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Sample records for adaptive inverse planning

  1. Expected treatment dose construction and adaptive inverse planning optimization: Implementation for offline head and neck cancer adaptive radiotherapy

    SciTech Connect

    Yan Di; Liang Jian

    2013-02-15

    Purpose: To construct expected treatment dose for adaptive inverse planning optimization, and evaluate it on head and neck (h and n) cancer adaptive treatment modification. Methods: Adaptive inverse planning engine was developed and integrated in our in-house adaptive treatment control system. The adaptive inverse planning engine includes an expected treatment dose constructed using the daily cone beam (CB) CT images in its objective and constrains. Feasibility of the adaptive inverse planning optimization was evaluated retrospectively using daily CBCT images obtained from the image guided IMRT treatment of 19 h and n cancer patients. Adaptive treatment modification strategies with respect to the time and the number of adaptive inverse planning optimization during the treatment course were evaluated using the cumulative treatment dose in organs of interest constructed using all daily CBCT images. Results: Expected treatment dose was constructed to include both the delivered dose, to date, and the estimated dose for the remaining treatment during the adaptive treatment course. It was used in treatment evaluation, as well as in constructing the objective and constraints for adaptive inverse planning optimization. The optimization engine is feasible to perform planning optimization based on preassigned treatment modification schedule. Compared to the conventional IMRT, the adaptive treatment for h and n cancer illustrated clear dose-volume improvement for all critical normal organs. The dose-volume reductions of right and left parotid glands, spine cord, brain stem and mandible were (17 {+-} 6)%, (14 {+-} 6)%, (11 {+-} 6)%, (12 {+-} 8)%, and (5 {+-} 3)% respectively with the single adaptive modification performed after the second treatment week; (24 {+-} 6)%, (22 {+-} 8)%, (21 {+-} 5)%, (19 {+-} 8)%, and (10 {+-} 6)% with three weekly modifications; and (28 {+-} 5)%, (25 {+-} 9)%, (26 {+-} 5)%, (24 {+-} 8)%, and (15 {+-} 9)% with five weekly modifications. Conclusions

  2. Organ sample generator for expected treatment dose construction and adaptive inverse planning optimization

    SciTech Connect

    Nie Xiaobo; Liang Jian; Yan Di

    2012-12-15

    Purpose: To create an organ sample generator (OSG) for expected treatment dose construction and adaptive inverse planning optimization. The OSG generates random samples of organs of interest from a distribution obeying the patient specific organ variation probability density function (PDF) during the course of adaptive radiotherapy. Methods: Principle component analysis (PCA) and a time-varying least-squares regression (LSR) method were used on patient specific geometric variations of organs of interest manifested on multiple daily volumetric images obtained during the treatment course. The construction of the OSG includes the determination of eigenvectors of the organ variation using PCA, and the determination of the corresponding coefficients using time-varying LSR. The coefficients can be either random variables or random functions of the elapsed treatment days depending on the characteristics of organ variation as a stationary or a nonstationary random process. The LSR method with time-varying weighting parameters was applied to the precollected daily volumetric images to determine the function form of the coefficients. Eleven h and n cancer patients with 30 daily cone beam CT images each were included in the evaluation of the OSG. The evaluation was performed using a total of 18 organs of interest, including 15 organs at risk and 3 targets. Results: Geometric variations of organs of interest during h and n cancer radiotherapy can be represented using the first 3 {approx} 4 eigenvectors. These eigenvectors were variable during treatment, and need to be updated using new daily images obtained during the treatment course. The OSG generates random samples of organs of interest from the estimated organ variation PDF of the individual. The accuracy of the estimated PDF can be improved recursively using extra daily image feedback during the treatment course. The average deviations in the estimation of the mean and standard deviation of the organ variation PDF for h

  3. Toward adaptive stereotactic robotic brachytherapy for prostate cancer: Demonstration of an adaptive workflow incorporating inverse planning and an MR stealth robot

    PubMed Central

    CUNHA, J. ADAM; HSU, I-CHOW; POULIOT, JEAN; ROACH, MACK; SHINOHARA, KATSUTO; KURHANEWICZ, JOHN; REED, GALEN; STOIANOVICI, DAN

    2011-01-01

    To translate any robot into a clinical environment, it is critical that the robot can seamlessly integrate with all the technology of a modern clinic. MRBot, an MR-stealth brachytherapy delivery device, was used in a closed-bore 3T MRI and a clinical brachytherapy cone beam CT suite. Targets included ceramic dummy seeds, MR-Spectroscopy-sensitive metabolite, and a prostate phantom. Acquired DICOM images were exported to planning software to register the robot coordinates in the imager’s frame, contour and verify target locations, create dose plans, and export needle and seed positions to the robot. The coordination of each system element (imaging device, brachytherapy planning system, robot control, robot) was validated with a seed delivery accuracy of within 2 mm in both a phantom and soft tissue. An adaptive workflow was demonstrated by acquiring images after needle insertion and prior to seed deposition. This allows for adjustment if the needle is in the wrong position. Inverse planning (IPSA) was used to generate a seed placement plan and coordinates for ten needles and 29 seeds were transferred to the robot. After every two needles placed, an image was acquired. The placed seeds were identified and validated prior to placing the seeds in the next two needles. The ability to robotically deliver seeds to locations determined by IPSA and the ability of the system to incorporate novel needle patterns were demonstrated. Shown here is the ability to overcome this critical step. An adaptive brachytherapy workflow is demonstrated which integrates a clinical anatomy-based seed location optimization engine and a robotic brachytherapy device. Demonstration of this workflow is a key element of a successful translation to the clinic of the MRI stealth robotic delivery system, MRBot. PMID:20642386

  4. Toward adaptive stereotactic robotic brachytherapy for prostate cancer: demonstration of an adaptive workflow incorporating inverse planning and an MR stealth robot.

    PubMed

    Cunha, J Adam; Hsu, I-Chow; Pouliot, Jean; Roach Iii, Mack; Shinohara, Katsuto; Kurhanewicz, John; Reed, Galen; Stoianovici, Dan

    2010-08-01

    To translate any robot into a clinical environment, it is critical that the robot can seamlessly integrate with all the technology of a modern clinic. MRBot, an MR-stealth brachytherapy delivery device, was used in a closed-bore 3T MRI and a clinical brachytherapy cone beam CT suite. Targets included ceramic dummy seeds, MR-Spectroscopy-sensitive metabolite, and a prostate phantom. Acquired DICOM images were exported to planning software to register the robot coordinates in the imager's frame, contour and verify target locations, create dose plans, and export needle and seed positions to the robot. The coordination of each system element (imaging device, brachytherapy planning system, robot control, robot) was validated with a seed delivery accuracy of within 2 mm in both a phantom and soft tissue. An adaptive workflow was demonstrated by acquiring images after needle insertion and prior to seed deposition. This allows for adjustment if the needle is in the wrong position. Inverse planning (IPSA) was used to generate a seed placement plan and coordinates for ten needles and 29 seeds were transferred to the robot. After every two needles placed, an image was acquired. The placed seeds were identified and validated prior to placing the seeds in the next two needles. The ability to robotically deliver seeds to locations determined by IPSA and the ability of the system to incorporate novel needle patterns were demonstrated. Shown here is the ability to overcome this critical step. An adaptive brachytherapy workflow is demonstrated which integrates a clinical anatomy-based seed location optimization engine and a robotic brachytherapy device. Demonstration of this workflow is a key element of a successful translation to the clinic of the MRI stealth robotic delivery system, MRBot.

  5. Inverse-consistent rigid registration of CT and MR for MR-based planning and adaptive prostate radiation therapy

    NASA Astrophysics Data System (ADS)

    Rivest-Hénault, David; Dowson, Nicholas; Greer, Peter; Dowling, Jason

    2014-03-01

    MRI-alone treatment planning and adaptive MRI-based prostate radiation therapy are two promising techniques that could significantly increase the accuracy of the curative dose delivery processes while reducing the total radiation dose. State-of-the-art methods rely on the registration of a patient MRI with a MR-CT atlas for the estimation of pseudo-CT [5]. This atlas itself is generally created by registering many CT and MRI pairs. Most registration methods are not symmetric, but the order of the images influences the result [8]. The computed transformation is therefore biased, introducing unwanted variability. This work examines how much a symmetric algorithm improves the registration. Methods: A robust symmetric registration algorithm is proposed that simultaneously optimises a half space transform and its inverse. During the registration process, the two input volumetric images are transformed to a common position in space, therefore minimising any computational bias. An asymmetrical implementation of the same algorithm was used for comparison purposes. Results: Whole pelvis MRI and CT scans from 15 prostate patients were registered, as in the creation of MR-CT atlases. In each case, two registrations were performed, with different input image orders, and the transformation error quantified. Mean residuals of 0.63±0.26 mm (translation) and (8.7±7.3) × 10--3 rad (rotation) were found for the asymmetrical implementation with corresponding values of 0.038±0.039 mm and (1.6 ± 1.3) × 10--3 rad for the proposed symmetric algorithm, a substantial improvement. Conclusions: The increased registration precision will enhance the generation of pseudo-CT from MRI for atlas based MR planning methods.

  6. Action Understanding as Inverse Planning

    ERIC Educational Resources Information Center

    Baker, Chris L.; Saxe, Rebecca; Tenenbaum, Joshua B.

    2009-01-01

    Humans are adept at inferring the mental states underlying other agents' actions, such as goals, beliefs, desires, emotions and other thoughts. We propose a computational framework based on Bayesian inverse planning for modeling human action understanding. The framework represents an intuitive theory of intentional agents' behavior based on the…

  7. Hybrid Adaptive Flight Control with Model Inversion Adaptation

    NASA Technical Reports Server (NTRS)

    Nguyen, Nhan

    2011-01-01

    This study investigates a hybrid adaptive flight control method as a design possibility for a flight control system that can enable an effective adaptation strategy to deal with off-nominal flight conditions. The hybrid adaptive control blends both direct and indirect adaptive control in a model inversion flight control architecture. The blending of both direct and indirect adaptive control provides a much more flexible and effective adaptive flight control architecture than that with either direct or indirect adaptive control alone. The indirect adaptive control is used to update the model inversion controller by an on-line parameter estimation of uncertain plant dynamics based on two methods. The first parameter estimation method is an indirect adaptive law based on the Lyapunov theory, and the second method is a recursive least-squares indirect adaptive law. The model inversion controller is therefore made to adapt to changes in the plant dynamics due to uncertainty. As a result, the modeling error is reduced that directly leads to a decrease in the tracking error. In conjunction with the indirect adaptive control that updates the model inversion controller, a direct adaptive control is implemented as an augmented command to further reduce any residual tracking error that is not entirely eliminated by the indirect adaptive control.

  8. Action understanding as inverse planning.

    PubMed

    Baker, Chris L; Saxe, Rebecca; Tenenbaum, Joshua B

    2009-12-01

    Humans are adept at inferring the mental states underlying other agents' actions, such as goals, beliefs, desires, emotions and other thoughts. We propose a computational framework based on Bayesian inverse planning for modeling human action understanding. The framework represents an intuitive theory of intentional agents' behavior based on the principle of rationality: the expectation that agents will plan approximately rationally to achieve their goals, given their beliefs about the world. The mental states that caused an agent's behavior are inferred by inverting this model of rational planning using Bayesian inference, integrating the likelihood of the observed actions with the prior over mental states. This approach formalizes in precise probabilistic terms the essence of previous qualitative approaches to action understanding based on an "intentional stance" [Dennett, D. C. (1987). The intentional stance. Cambridge, MA: MIT Press] or a "teleological stance" [Gergely, G., Nádasdy, Z., Csibra, G., & Biró, S. (1995). Taking the intentional stance at 12 months of age. Cognition, 56, 165-193]. In three psychophysical experiments using animated stimuli of agents moving in simple mazes, we assess how well different inverse planning models based on different goal priors can predict human goal inferences. The results provide quantitative evidence for an approximately rational inference mechanism in human goal inference within our simplified stimulus paradigm, and for the flexible nature of goal representations that human observers can adopt. We discuss the implications of our experimental results for human action understanding in real-world contexts, and suggest how our framework might be extended to capture other kinds of mental state inferences, such as inferences about beliefs, or inferring whether an entity is an intentional agent.

  9. Chromosome inversions, adaptive cassettes and the evolution of species' ranges.

    PubMed

    Kirkpatrick, Mark; Barrett, Brian

    2015-05-01

    A chromosome inversion can spread when it captures locally adapted alleles or when it is introduced into a species by hybridization with adapted alleles that were previously absent. We present a model that shows how both processes can cause a species range to expand. Introgression of an inversion that carries novel, locally adapted alleles is a particularly powerful mechanism for range expansion. The model supports the earlier proposal that introgression of an inversion triggered a large range expansion of a malaria mosquito. These results suggest a role for inversions as cassettes of genes that can accelerate adaptation by crossing species boundaries, rather than protecting genomes from introgression.

  10. Chromosome inversions, adaptive cassettes and the evolution of species' ranges.

    PubMed

    Kirkpatrick, Mark; Barrett, Brian

    2015-05-01

    A chromosome inversion can spread when it captures locally adapted alleles or when it is introduced into a species by hybridization with adapted alleles that were previously absent. We present a model that shows how both processes can cause a species range to expand. Introgression of an inversion that carries novel, locally adapted alleles is a particularly powerful mechanism for range expansion. The model supports the earlier proposal that introgression of an inversion triggered a large range expansion of a malaria mosquito. These results suggest a role for inversions as cassettes of genes that can accelerate adaptation by crossing species boundaries, rather than protecting genomes from introgression. PMID:25583098

  11. Genomic Evidence for Adaptive Inversion Clines in Drosophila melanogaster.

    PubMed

    Kapun, Martin; Fabian, Daniel K; Goudet, Jérôme; Flatt, Thomas

    2016-05-01

    Clines in chromosomal inversion polymorphisms-presumably driven by climatic gradients-are common but there is surprisingly little evidence for selection acting on them. Here we address this long-standing issue in Drosophila melanogaster by using diagnostic single nucleotide polymorphism (SNP) markers to estimate inversion frequencies from 28 whole-genome Pool-seq samples collected from 10 populations along the North American east coast. Inversions In(3L)P, In(3R)Mo, and In(3R)Payne showed clear latitudinal clines, and for In(2L)t, In(2R)NS, and In(3R)Payne the steepness of the clinal slopes changed between summer and fall. Consistent with an effect of seasonality on inversion frequencies, we detected small but stable seasonal fluctuations of In(2R)NS and In(3R)Payne in a temperate Pennsylvanian population over 4 years. In support of spatially varying selection, we observed that the cline in In(3R)Payne has remained stable for >40 years and that the frequencies of In(2L)t and In(3R)Payne are strongly correlated with climatic factors that vary latitudinally, independent of population structure. To test whether these patterns are adaptive, we compared the amount of genetic differentiation of inversions versus neutral SNPs and found that the clines in In(2L)t and In(3R)Payne are maintained nonneutrally and independent of admixture. We also identified numerous clinal inversion-associated SNPs, many of which exhibit parallel differentiation along the Australian cline and reside in genes known to affect fitness-related traits. Together, our results provide strong evidence that inversion clines are maintained by spatially-and perhaps also temporally-varying selection. We interpret our data in light of current hypotheses about how inversions are established and maintained. PMID:26796550

  12. An adaptive inverse kinematics algorithm for robot manipulators

    NASA Technical Reports Server (NTRS)

    Colbaugh, R.; Glass, K.; Seraji, H.

    1990-01-01

    An adaptive algorithm for solving the inverse kinematics problem for robot manipulators is presented. The algorithm is derived using model reference adaptive control (MRAC) theory and is computationally efficient for online applications. The scheme requires no a priori knowledge of the kinematics of the robot if Cartesian end-effector sensing is available, and it requires knowledge of only the forward kinematics if joint position sensing is used. Computer simulation results are given for the redundant seven-DOF robotics research arm, demonstrating that the proposed algorithm yields accurate joint angle trajectories for a given end-effector position/orientation trajectory.

  13. Effects of adaptive refinement on the inverse EEG solution

    NASA Astrophysics Data System (ADS)

    Weinstein, David M.; Johnson, Christopher R.; Schmidt, John A.

    1995-10-01

    One of the fundamental problems in electroencephalography can be characterized by an inverse problem. Given a subset of electrostatic potentials measured on the surface of the scalp and the geometry and conductivity properties within the head, calculate the current vectors and potential fields within the cerebrum. Mathematically the generalized EEG problem can be stated as solving Poisson's equation of electrical conduction for the primary current sources. The resulting problem is mathematically ill-posed i.e., the solution does not depend continuously on the data, such that small errors in the measurement of the voltages on the scalp can yield unbounded errors in the solution, and, for the general treatment of a solution of Poisson's equation, the solution is non-unique. However, if accurate solutions the general treatment of a solution of Poisson's equation, the solution is non-unique. However, if accurate solutions to such problems could be obtained, neurologists would gain noninvasive accesss to patient-specific cortical activity. Access to such data would ultimately increase the number of patients who could be effectively treated for pathological cortical conditions such as temporal lobe epilepsy. In this paper, we present the effects of spatial adaptive refinement on the inverse EEG problem and show that the use of adaptive methods allow for significantly better estimates of electric and potential fileds within the brain through an inverse procedure. To test these methods, we have constructed several finite element head models from magneteic resonance images of a patient. The finite element meshes ranged in size from 2724 nodes and 12,812 elements to 5224 nodes and 29,135 tetrahedral elements, depending on the level of discretization. We show that an adaptive meshing algorithm minimizes the error in the forward problem due to spatial discretization and thus increases the accuracy of the inverse solution.

  14. Rapid inversion of velocity map images for adaptive femtosecond control

    NASA Astrophysics Data System (ADS)

    Rallis, C.; Andrews, P.; Averin, R.; Jochim, B.; Gregerson, N.; Wells, E.; Zohrabi, M.; de, S.; Gaire, B.; Carnes, K. D.; Ben-Itzhak, I.; Bergues, B.; Kling, M. F.

    2011-05-01

    We report techniques developed to utilize three dimensional momentum information as feedback in adaptive femtosecond control of molecular systems. Velocity map imaging of the dissociating ions following interaction with an intense ultrafast laser pulse provides raw data. In order to recover momentum information, however, the two-dimensional image must be inverted to reconstruct the three-dimensional photofragment distribution. Using a variation of the onion-peeling technique, we invert 1054 × 1040 pixel images in under 1 second. This rapid inversion allows a slice of the momentum distribution to be used as feedback in a closed-loop adaptive control scheme. We report techniques developed to utilize three dimensional momentum information as feedback in adaptive femtosecond control of molecular systems. Velocity map imaging of the dissociating ions following interaction with an intense ultrafast laser pulse provides raw data. In order to recover momentum information, however, the two-dimensional image must be inverted to reconstruct the three-dimensional photofragment distribution. Using a variation of the onion-peeling technique, we invert 1054 × 1040 pixel images in under 1 second. This rapid inversion allows a slice of the momentum distribution to be used as feedback in a closed-loop adaptive control scheme. This work supported by National Science Foundation award PHY-0969687 and the Chemical Sciences, Geosciences, and Biosciences Division, Office of Basic Energy Science, Office of Science, US Department of Energy.

  15. Climate adaptation planning in practice: an evaluation of adaptation plans from three developed nations

    SciTech Connect

    Preston, Benjamin L; Westaway, Richard M.; Yuen, Emma J.

    2011-04-01

    Formal planning for climate change adaptation is emerging rapidly at a range of geo-political scales. This first generation of adaptation plans provides useful information regarding how institutions are framing the issue of adaptation and the range of processes that are recognized as being part of an adaptation response. To better understand adaptation planning among developed nations, a set of 57 adaptation plans from Australia, the United Kingdom and the United States was evaluated against a suite of 19 planning processes identified from existing guidance instruments for adaptation planning. Total scores among evaluated plans ranged from 16% of the maximum possible score to 61%, with an average of 37%. These results suggest adaptation plans are largely under-developed. Critical weaknesses in adaptation planning are related to limited consideration for non-climatic factors as well as neglect for issues of adaptive capacity including entitlements to various forms of capital needed for effective adaptation. Such gaps in planning suggest there are opportunities for institutions to make better use of existing guidance for adaptation planning and the need to consider the broader governance context in which adaptation will occur. In addition, the adaptation options prescribed by adaptation plans reflect a preferential bias toward low-risk capacity-building (72% of identified options) over the delivery of specific actions to reduce vulnerability. To the extent these findings are representative of the state of developed nation adaptation planning, there appear to be significant deficiencies in climate change preparedness, even among those nations often assumed to have the greatest adaptive capacity.

  16. Inversions and adaptation to the plant toxin ouabain shape DNA sequence variation within and between chromosomal inversions of Drosophila subobscura.

    PubMed Central

    Pegueroles, Cinta; Ferrés-Coy, Albert; Martí-Solano, Maria; Aquadro, Charles F; Pascual, Marta; Mestres, Francesc

    2016-01-01

    Adaptation is defined as an evolutionary process allowing organisms to succeed in certain habitats or conditions. Chromosomal inversions have the potential to be key in the adaptation processes, since they can contribute to the maintenance of favoured combinations of adaptive alleles through reduced recombination between individuals carrying different inversions. We have analysed six genes (Pif1A, Abi, Sqd, Yrt, Atpα and Fmr1), located inside and outside three inversions of the O chromosome in European populations of Drosophila subobscura. Genetic differentiation was significant between inversions despite extensive recombination inside inverted regions, irrespective of gene distance to the inversion breakpoints. Surprisingly, the highest level of genetic differentiation between arrangements was found for the Atpα gene, which is located outside the O1 and O7 inversions. Two derived unrelated arrangements (O3+4+1 and O3+4+7) are nearly fixed for several amino acid substitutions at the Atpα gene that have been described to confer resistance in other species to the cardenolide ouabain, a plant toxin capable of blocking ATPases. Similarities in the Atpα variants, conferring ouabain resistance in both arrangements, may be the result of convergent substitution and be favoured in response to selective pressures presumably related to the presence of plants containing ouabain in the geographic locations where both inversions are present. PMID:27029337

  17. Adaptive path planning for flexible manufacturing

    SciTech Connect

    Chen, Pang C.

    1994-08-01

    Path planning needs to be fast to facilitate real-time robot programming. Unfortunately, current planning techniques are still too slow to be effective, as they often require several minutes, if not hours of computation. To overcome this difficulty, we present an adaptive algorithm that uses past experience to speed up future performance. It is a learning algorithm suitable for automating flexible manufacturing in incrementally-changing environments. The algorithm allows the robot to adapt to its environment by having two experience manipulation schemes: For minor environmental change, we use an object-attached experience abstraction scheme to increase the flexibility of the learned experience; for major environmental change, we use an on-demand experience repair scheme to retain those experiences that remain valid and useful. Using this algorithm, we can effectively reduce the overall robot planning time by re-using the computation result for one task to plan a path for another.

  18. Adaptation Challenges and Emerging Efforts in Adaptation Planning in California

    NASA Astrophysics Data System (ADS)

    Moser, S. C.

    2008-12-01

    Following Governor Schwarzenegger's Executive Order (S-03-05) of 2005, numerous researchers have been engaged in an ongoing assessment effort to support the state's mitigation and adaptation efforts. Under the sponsorship and coordination of the California Energy Commission's Public Interest Energy Research (PIER) Program, a wide range of climate change impacts and adaptation studies are being conducted and summarized on a biannual basis to assess the latest climate change science, potential impacts on critical sectors, and the state's efforts to manage its climate change risks. In the past, adaptation needs assessments in the state have primarily used a hazards-based (i.e., climate scenario-driven, top-down) approach, while vulnerability-based, bottom-up studies are only now emerging. They are increasingly viewed as complementary and necessary to adequately inform adaptation strategies. This paper briefly highlights this assessment history and then focuses on the planning efforts currently underway to prepare California's first state-wide adaptation plan. As the science and policy/management evolve in tandem, this paper will suggest future policy- or use-inspired research areas, and offer recommendations on how to improve interaction between researchers and practitioners at the science-policy interface, in order to build the state's decision support capacity in the face of a rapidly changing climate.

  19. Resampling: An optimization method for inverse planning in robotic radiosurgery

    SciTech Connect

    Schweikard, Achim; Schlaefer, Alexander; Adler, John R. Jr.

    2006-11-15

    By design, the range of beam directions in conventional radiosurgery are constrained to an isocentric array. However, the recent introduction of robotic radiosurgery dramatically increases the flexibility of targeting, and as a consequence, beams need be neither coplanar nor isocentric. Such a nonisocentric design permits a large number of distinct beam directions to be used in one single treatment. These major technical differences provide an opportunity to improve upon the well-established principles for treatment planning used with GammaKnife or LINAC radiosurgery. With this objective in mind, our group has developed over the past decade an inverse planning tool for robotic radiosurgery. This system first computes a set of beam directions, and then during an optimization step, weights each individual beam. Optimization begins with a feasibility query, the answer to which is derived through linear programming. This approach offers the advantage of completeness and avoids local optima. Final beam selection is based on heuristics. In this report we present and evaluate a new strategy for utilizing the advantages of linear programming to improve beam selection. Starting from an initial solution, a heuristically determined set of beams is added to the optimization problem, while beams with zero weight are removed. This process is repeated to sample a set of beams much larger compared with typical optimization. Experimental results indicate that the planning approach efficiently finds acceptable plans and that resampling can further improve its efficiency.

  20. Addressing uncertainty in adaptation planning for agriculture.

    PubMed

    Vermeulen, Sonja J; Challinor, Andrew J; Thornton, Philip K; Campbell, Bruce M; Eriyagama, Nishadi; Vervoort, Joost M; Kinyangi, James; Jarvis, Andy; Läderach, Peter; Ramirez-Villegas, Julian; Nicklin, Kathryn J; Hawkins, Ed; Smith, Daniel R

    2013-05-21

    We present a framework for prioritizing adaptation approaches at a range of timeframes. The framework is illustrated by four case studies from developing countries, each with associated characterization of uncertainty. Two cases on near-term adaptation planning in Sri Lanka and on stakeholder scenario exercises in East Africa show how the relative utility of capacity vs. impact approaches to adaptation planning differ with level of uncertainty and associated lead time. An additional two cases demonstrate that it is possible to identify uncertainties that are relevant to decision making in specific timeframes and circumstances. The case on coffee in Latin America identifies altitudinal thresholds at which incremental vs. transformative adaptation pathways are robust options. The final case uses three crop-climate simulation studies to demonstrate how uncertainty can be characterized at different time horizons to discriminate where robust adaptation options are possible. We find that impact approaches, which use predictive models, are increasingly useful over longer lead times and at higher levels of greenhouse gas emissions. We also find that extreme events are important in determining predictability across a broad range of timescales. The results demonstrate the potential for robust knowledge and actions in the face of uncertainty.

  1. Addressing uncertainty in adaptation planning for agriculture

    PubMed Central

    Vermeulen, Sonja J.; Challinor, Andrew J.; Thornton, Philip K.; Campbell, Bruce M.; Eriyagama, Nishadi; Vervoort, Joost M.; Kinyangi, James; Jarvis, Andy; Läderach, Peter; Ramirez-Villegas, Julian; Nicklin, Kathryn J.; Hawkins, Ed; Smith, Daniel R.

    2013-01-01

    We present a framework for prioritizing adaptation approaches at a range of timeframes. The framework is illustrated by four case studies from developing countries, each with associated characterization of uncertainty. Two cases on near-term adaptation planning in Sri Lanka and on stakeholder scenario exercises in East Africa show how the relative utility of capacity vs. impact approaches to adaptation planning differ with level of uncertainty and associated lead time. An additional two cases demonstrate that it is possible to identify uncertainties that are relevant to decision making in specific timeframes and circumstances. The case on coffee in Latin America identifies altitudinal thresholds at which incremental vs. transformative adaptation pathways are robust options. The final case uses three crop–climate simulation studies to demonstrate how uncertainty can be characterized at different time horizons to discriminate where robust adaptation options are possible. We find that impact approaches, which use predictive models, are increasingly useful over longer lead times and at higher levels of greenhouse gas emissions. We also find that extreme events are important in determining predictability across a broad range of timescales. The results demonstrate the potential for robust knowledge and actions in the face of uncertainty. PMID:23674681

  2. Object-adapted inverse pattern projection: generation, evaluation, and applications

    NASA Astrophysics Data System (ADS)

    Bothe, Thorsten; Li, Wansong; von Kopylow, Christoph; Juptner, Werner P.

    2003-05-01

    Fast and robust 3D quality control as well as fast deformation measurement is of particular importance for industrial inspection. Additionally a direct response about measured properties is desired. Therefore, robust optical techniques are needed which use as few images as possible for measurement and visualize results in an efficient way. One promising technique for this aim is the inverse pattern projection which has the following advantages: The technique codes the information of a preceding measurement into the projected inverse pattern. Thus, it is possible to do differential measurements using only one camera frame for each state. Additionally, the results are optimized straight fringes for sampling which are independent of the object curvature. The ability to use any image for inverse projection enables the use for augmented reality, i.e. any properties can be visualized directly on the object's surface which makes inspections easier than with use of a separated indicating device. The hardware needs are low as just a programmable projector and a standard camera are necessary. The basic idea of inverse pattern projection, necessary algorithms ane found optimizations are demonstrated, roughly. Evaluation techniques were found to preserve a high quality phase measurement under imperfect conditions. The different application fields can be sorted out by the type of pattern used for inverse projection. We select two main topics for presentation. One is the incremental (one image per state) deformation measurement which is a promising technique for high speed deformation measurements. A video series of a wavering flag with projected inverse pattern was evaluated to show the complete deformation series. The other application is the optical feature marking (augmented reality) that allows to map any measured result directly onto the object under investigation. The general ability to straighten any kind of information on 3D surfaces is shown while preserving an exact

  3. Adaptive planning of emergency aerial photogrammetric mission

    NASA Astrophysics Data System (ADS)

    Shen, Fuqiang; Zhu, Qing; Zhang, Junxiao; Miao, Shuangxi; Zhou, Xingxia; Cao, Zhenyu

    2015-12-01

    Aiming at the diversity of emergency aerial photogrammetric mission requirements, complex ground and air environmental constraints make the planning mission time-consuming. This paper presents a fast adaptation for the UAV aerial photogrammetric mission planning. First, Building emergency aerial UAVs mission the unified expression of UAVs model and mechanical model of performance parameters in the semantic space make the integrated expression of mission requirements and low altitude environment. Proposed match assessment method which based on resource and mission efficiency. Made the Adaptive match of UAV aerial resources and mission. According to the emergency aerial resource properties, considering complex air-ground environment and mission requirements constraints. Made accurate design of UAV route. Experimental results show, the method scientific and efficient, greatly enhanced the emergency response rate.

  4. Adaptive robot path planning in changing environments

    SciTech Connect

    Chen, P.C.

    1994-08-01

    Path planning needs to be fast to facilitate real-time robot programming. Unfortunately, current planning techniques are still too slow to be effective, as they often require several minutes, if not hours of computation. To overcome this difficulty, we present an adaptive algorithm that uses past experience to speed up future performance. It is a learning algorithm suitable for incrementally-changing environments such as those encountered in manufacturing of evolving products and waste-site remediation. The algorithm allows the robot to adapt to its environment by having two experience manipulation schemes: For minor environmental change, we use an object-attached experience abstraction scheme to increase the flexibility of the learned experience; for major environmental change, we use an on-demand experience repair scheme to retain those experiences that remain valid and useful. Using this algorithm, we can effectively reduce the overall robot planning time by re-using the computation result for one task to plan a path for another.

  5. Inverse planning of energy-modulated electron beams in radiotherapy

    SciTech Connect

    Gentry, John R. . E-mail: gentryj@gmh.org; Steeves, Richard; Paliwal, Bhudatt A.

    2006-01-01

    The use of megavoltage electron beams often poses a clinical challenge in that the planning target volume (PTV) is anterior to other radiosensitive structures and has variable depth. To ensure that skin as well as the deepest extent of the PTV receives the prescribed dose entails prescribing to a point beyond the depth of peak dose for a single electron energy. This causes dose inhomogeneities and heightened potential for tissue fibrosis, scarring, and possible soft tissue necrosis. Use of bolus on the skin improves the entrant dose at the cost of decreasing the therapeutic depth that can be treated. Selection of a higher energy to improve dose homogeneity results in increased dose to structures beyond the PTV, as well as enlargement of the volume receiving heightened dose. Measured electron data from a linear accelerator was used as input to create an inverse planning tool employing energy and intensity modulation using bolus (e-IMRT{sup TM}). Using tools readily available in a radiotherapy department, the applications of energy and intensity modulation on the central axis makes it possible to remove hot spots of 115% or more over the depths clinically encountered. The e-IMRT{sup TM} algorithm enables the development of patient-specific dose distributions with user-defined positions of peak dose, range, and reduced dose to points beyond the prescription point.

  6. Genomic evidence for role of inversion 3RP of Drosophila melanogaster in facilitating climate change adaptation.

    PubMed

    Rane, Rahul V; Rako, Lea; Kapun, Martin; Lee, Siu F; Hoffmann, Ary A

    2015-05-01

    Chromosomal inversion polymorphisms are common in animals and plants, and recent models suggest that alternative arrangements spread by capturing different combinations of alleles acting additively or epistatically to favour local adaptation. It is also thought that inversions typically maintain favoured combinations for a long time by suppressing recombination between alternative chromosomal arrangements. Here, we consider patterns of linkage disequilibrium and genetic divergence in an old inversion polymorphism in Drosophila melanogaster (In(3R)Payne) known to be associated with climate change adaptation and a recent invasion event into Australia. We extracted, karyotyped and sequenced whole chromosomes from two Australian populations, so that changes in the arrangement of the alleles between geographically separated tropical and temperate areas could be compared. Chromosome-wide linkage disequilibrium (LD) analysis revealed strong LD within the region spanned by In(3R)Payne. This genomic region also showed strong differentiation between the tropical and the temperate populations, but no differentiation between different karyotypes from the same population, after controlling for chromosomal arrangement. Patterns of differentiation across the chromosome arm and in gene ontologies were enhanced by the presence of the inversion. These data support the notion that inversions are strongly selected by bringing together combinations of genes, but it is still not clear if such combinations act additively or epistatically. Our data suggest that climatic adaptation through inversions can be dynamic, reflecting changes in the relative abundance of different forms of an inversion and ongoing evolution of allelic content within an inversion.

  7. Adaptive path planning: Algorithm and analysis

    SciTech Connect

    Chen, Pang C.

    1993-03-01

    Path planning has to be fast to support real-time robot programming. Unfortunately, current planning techniques are still too slow to be effective, as they often require several minutes, if not hours of computation. To alleviate this problem, we present a learning algorithm that uses past experience to enhance future performance. The algorithm relies on an existing path planner to provide solutions to difficult tasks. From these solutions, an evolving sparse network of useful subgoals is learned to support faster planning. The algorithm is suitable for both stationary and incrementally-changing environments. To analyze our algorithm, we use a previously developed stochastic model that quantifies experience utility. Using this model, we characterize the situations in which the adaptive planner is useful, and provide quantitative bounds to predict its behavior. The results are demonstrated with problems in manipulator planning. Our algorithm and analysis are sufficiently general that they may also be applied to task planning or other planning domains in which experience is useful.

  8. Novel tools for stepping source brachytherapy treatment planning: Enhanced geometrical optimization and interactive inverse planning

    SciTech Connect

    Dinkla, Anna M. Laarse, Rob van der; Koedooder, Kees; Petra Kok, H.; Wieringen, Niek van; Pieters, Bradley R.; Bel, Arjan

    2015-01-15

    Purpose: Dose optimization for stepping source brachytherapy can nowadays be performed using automated inverse algorithms. Although much quicker than graphical optimization, an experienced treatment planner is required for both methods. With automated inverse algorithms, the procedure to achieve the desired dose distribution is often based on trial-and-error. Methods: A new approach for stepping source prostate brachytherapy treatment planning was developed as a quick and user-friendly alternative. This approach consists of the combined use of two novel tools: Enhanced geometrical optimization (EGO) and interactive inverse planning (IIP). EGO is an extended version of the common geometrical optimization method and is applied to create a dose distribution as homogeneous as possible. With the second tool, IIP, this dose distribution is tailored to a specific patient anatomy by interactively changing the highest and lowest dose on the contours. Results: The combined use of EGO–IIP was evaluated on 24 prostate cancer patients, by having an inexperienced user create treatment plans, compliant to clinical dose objectives. This user was able to create dose plans of 24 patients in an average time of 4.4 min/patient. An experienced treatment planner without extensive training in EGO–IIP also created 24 plans. The resulting dose-volume histogram parameters were comparable to the clinical plans and showed high conformance to clinical standards. Conclusions: Even for an inexperienced user, treatment planning with EGO–IIP for stepping source prostate brachytherapy is feasible as an alternative to current optimization algorithms, offering speed, simplicity for the user, and local control of the dose levels.

  9. Functional error estimators for the adaptive discretization of inverse problems

    NASA Astrophysics Data System (ADS)

    Clason, Christian; Kaltenbacher, Barbara; Wachsmuth, Daniel

    2016-10-01

    So-called functional error estimators provide a valuable tool for reliably estimating the discretization error for a sum of two convex functions. We apply this concept to Tikhonov regularization for the solution of inverse problems for partial differential equations, not only for quadratic Hilbert space regularization terms but also for nonsmooth Banach space penalties. Examples include the measure-space norm (i.e., sparsity regularization) or the indicator function of an {L}∞ ball (i.e., Ivanov regularization). The error estimators can be written in terms of residuals in the optimality system that can then be estimated by conventional techniques, thus leading to explicit estimators. This is illustrated by means of an elliptic inverse source problem with the above-mentioned penalties, and numerical results are provided for the case of sparsity regularization.

  10. Adaptive Role of Inversion Polymorphism of Drosophila subobscura in Lead Stressed Environment.

    PubMed

    Kenig, Bojan; Kurbalija Novičić, Zorana; Patenković, Aleksandra; Stamenković-Radak, Marina; Anđelković, Marko

    2015-01-01

    Local adaptation to environmental stress at different levels of genetic polymorphism in various plants and animals has been documented through evolution of heavy metal tolerance. We used samples of Drosophila subobscura populations from two differently polluted environments to analyze the change of chromosomal inversion polymorphism as genetic marker during laboratory exposure to lead. Exposure to environmental contamination can affect the genetic content within a particular inversion and produce targets for selection in populations from different environments. The aims were to discover whether the inversion polymorphism is shaped by the local natural environments, and if lead as a selection pressure would cause adaptive divergence of two populations during the multigenerational laboratory experiment. The results showed that populations retain signatures from past contamination events, and that heavy metal pollution can cause adaptive changes in population. Differences in inversion polymorphism between the two populations increased over generations under lead contamination in the laboratory. The inversion polymorphism of population originating from the more polluted natural environment was more stable during the experiment, both under conditions with and without lead. Therefore, results showed that inversion polymorphism as a genetic marker reflects a strong signature of adaptation to the local environment, and that historical demographic events and selection are important for both prediction of evolutionary potential and long-term viability of natural populations.

  11. Class solution for inversely planned permanent prostate implants to mimic an experienced dosimetrist

    SciTech Connect

    Lessard, Etienne; Kwa, Stefan L. S.; Pickett, Barby; Roach, Mach III; Pouliot, Jean

    2006-08-15

    The purpose of this paper is to present a method for the selection of inverse planning parameters and to establish a set of inverse planning parameters (class solution) for the inverse planning included in a commercial permanent prostate implant treatment planning system. The manual planning of more than 750 patients since 1996 led to the establishment of general treatment planning rules. A class solution is tuned to fulfill the treatment planning rules and generate equivalent implants. For ten patients, the inverse planning is compared with manual planning performed by our experienced physicist. The prostate volumes ranged from 17 to 51 cc and are implanted with low activity I-125 seeds. Dosimetric indices are calculated for comparison. The inverse planning needed about 15 s for each optimization (400 000 iterations on a 2.5 GHz PC). In comparison, the physicist needed about 20 min to perform each manual plan. A class solution is found that consistently produces dosimetric indices equivalent or better than the manual planning. Moreover, even with strict seed placement rules, the inverse planning can produce adequate prostate dose coverage and organ at risk protection. The inverse planning avoids implant with seeds outside of the prostate and too close to the urethra. It also avoids needles with only one seed and needles with three consecutive seeds. This reduces the risk of complication due to seed misplacement and edema. The inverse planning also uses a smaller number of needles, reducing the cause of trauma. The quality of the treatment plans is independent of the gland size and shape. A class solution is established that consistently and rapidly produces equivalent dosimetric indices as manual planning while respecting severe seed placement rules. The class solution can be used as a starting point for every patient, dramatically reducing the time needed to plan individual patient treatments. The class solution works with inverse preplanning, intraoperative

  12. A widespread chromosomal inversion polymorphism contributes to a major life-history transition, local adaptation, and reproductive isolation.

    PubMed

    Lowry, David B; Willis, John H

    2010-09-28

    The role of chromosomal inversions in adaptation and speciation is controversial. Historically, inversions were thought to contribute to these processes either by directly causing hybrid sterility or by facilitating the maintenance of co-adapted gene complexes. Because inversions suppress recombination when heterozygous, a recently proposed local adaptation mechanism predicts that they will spread if they capture alleles at multiple loci involved in divergent adaptation to contrasting environments. Many empirical studies have found inversion polymorphisms linked to putatively adaptive phenotypes or distributed along environmental clines. However, direct involvement of an inversion in local adaptation and consequent ecological reproductive isolation has not to our knowledge been demonstrated in nature. In this study, we discovered that a chromosomal inversion polymorphism is geographically widespread, and we test the extent to which it contributes to adaptation and reproductive isolation under natural field conditions. Replicated crosses between the prezygotically reproductively isolated annual and perennial ecotypes of the yellow monkeyflower, Mimulus guttatus, revealed that alternative chromosomal inversion arrangements are associated with life-history divergence over thousands of kilometers across North America. The inversion polymorphism affected adaptive flowering time divergence and other morphological traits in all replicated crosses between four pairs of annual and perennial populations. To determine if the inversion contributes to adaptation and reproductive isolation in natural populations, we conducted a novel reciprocal transplant experiment involving outbred lines, where alternative arrangements of the inversion were reciprocally introgressed into the genetic backgrounds of each ecotype. Our results demonstrate for the first time in nature the contribution of an inversion to adaptation, an annual/perennial life-history shift, and multiple reproductive

  13. Utilising pseudo-CT data for dose calculation and plan optimization in adaptive radiotherapy.

    PubMed

    Whelan, Brendan; Kumar, Shivani; Dowling, Jason; Begg, Jarrad; Lambert, Jonathan; Lim, Karen; Vinod, Shalini K; Greer, Peter B; Holloway, Lois

    2015-12-01

    To quantify the dose calculation error and resulting optimization uncertainty caused by performing inverse treatment planning on inaccurate electron density data (pseudo-CT) as needed for adaptive radiotherapy and Magnetic Resonance Imaging (MRI) based treatment planning. Planning Computer Tomography (CT) data from 10 cervix cancer patients was used to generate 4 pseudo-CT data sets. Each pseudo-CT was created based on an available method of assigning electron density to an anatomic image. An inversely modulated radiotherapy (IMRT) plan was developed on each planning CT. The dose calculation error caused by each pseudo-CT data set was quantified by comparing the dose calculated each pseudo-CT data set with that calculated on the original planning CT for the same IMRT plan. The optimization uncertainty introduced by the dose calculation error was quantified by re-optimizing the same optimization parameters on each pseudo-CT data set and comparing against the original planning CT. Dose differences were quantified by assessing the Equivalent Uniform Dose (EUD) for targets and relevant organs at risk. Across all pseudo-CT data sets and all organs, the absolute mean dose calculation error was 0.2 Gy, and was within 2 % of the prescription dose in 98.5 % of cases. Then absolute mean optimisation error was 0.3 Gy EUD, indicating that that inverse optimisation is impacted by the dose calculation error. However, the additional uncertainty introduced to plan optimisation is small compared the sources of variation which already exist. Use of inaccurate electron density data for inverse treatment planning results in a dose calculation error, which in turn introduces additional uncertainty into the plan optimization process. In this study, we showed that both of these effects are clinically acceptable for cervix cancer patients using four different pseudo-CT data sets. Dose calculation and inverse optimization on pseudo-CT is feasible for this patient cohort.

  14. Adaptive planning for applications with dynamic objectives

    NASA Technical Reports Server (NTRS)

    Hadavi, Khosrow; Hsu, Wen-Ling; Pinedo, Michael

    1992-01-01

    We devise a qualitative control layer to be integrated into a real-time multi-agent reactive planner. The reactive planning system consists of distributed planning agents attending to various perspectives of the task environment. Each perspective corresponds to an objective. The set of objectives considered are sometimes in conflict with each other. Each agent receives information about events as they occur, and a set of actions based on heuristics can be taken by the agents. Within the qualitative control scheme, we use a set of qualitative feature vectors to describe the effects of applying actions. A qualitative transition vector is used to denote the qualitative distance between the current state and the target state. We will then apply on-line learning at the qualitative control level to achieve adaptive planning. Our goal is to design a mechanism to refine the heuristics used by the reactive planner every time an action is taken toward achieving the objectives, using feedback from the results of the actions. When the outcome is compared with expectations, our prior objectives may be modified and a new set of objectives (or a new assessment of the relative importance of the different objectives) can be introduced. Because we are able to obtain better estimates of the time-varying objectives, the reactive strategies can be improved and better prediction can be achieved.

  15. Inversions

    ERIC Educational Resources Information Center

    Brown, Malcolm

    2009-01-01

    Inversions are fascinating phenomena. They are reversals of the normal or expected order. They occur across a wide variety of contexts. What do inversions have to do with learning spaces? The author suggests that they are a useful metaphor for the process that is unfolding in higher education with respect to education. On the basis of…

  16. Real-time fast inverse dose optimization for image guided adaptive radiation therapy-Enhancements to fast inverse dose optimization (FIDO)

    NASA Astrophysics Data System (ADS)

    Goldman, S. P.; Turnbull, D.; Johnson, C.; Chen, J. Z.; Battista, J. J.

    2009-05-01

    A fast, accurate and stable optimization algorithm is very important for inverse planning of intensity-modulated radiation therapy (IMRT), and for implementing dose-adaptive radiotherapy in the future. Conventional numerical search algorithms with positive beam weight constraints generally require numerous iterations and may produce suboptimal dose results due to trapping in local minima regions of the objective function landscape. A direct solution of the inverse problem using conventional quadratic objective functions without positive beam constraints is more efficient but it will result in unrealistic negative beam weights. We review here a direct solution of the inverse problem that is efficient and does not yield unphysical negative beam weights. In fast inverse dose optimization (FIDO) method the objective function for the optimization of a large number of beamlets is reformulated such that the optimization problem is reducible to a linear set of equations. The optimal set of intensities is then found through a matrix inversion, and negative beamlet intensities are avoided without the need for externally imposed ad hoc conditions. In its original version [S. P. Goldman, J. Z. Chen, and J. J. Battista, in Proceedings of the XIVth International Conference on the Use of Computers in Radiation Therapy, 2004, pp. 112-115; S. P. Goldman, J. Z. Chen, and J. J. Battista, Med. Phys. 32, 3007 (2005)], FIDO was tested on single two-dimensional computed tomography (CT) slices with sharp KERMA beams without scatter, in order to establish a proof of concept which demonstrated that FIDO could be a viable method for the optimization of cancer treatment plans. In this paper we introduce the latest advancements in FIDO that now include not only its application to three-dimensional volumes irradiated by beams with full scatter but include as well a complete implementation of clinical dose-volume constraints including maximum and minimum dose as well as equivalent uniform dose

  17. Impulse radar imaging for dispersive concrete using inverse adaptive filtering techniques

    SciTech Connect

    Arellano, J.; Hernandez, J.M.; Brase, J.

    1993-05-01

    This publication addresses applications of a delayed inverse model adaptive filter for modeled data obtained from short-pulse radar reflectometry. To determine the integrity of concrete, a digital adaptive filter was used, which allows compensation of dispersion and clutter generated by the concrete. A standard set of weights produced by an adaptive filter are used on modeled data to obtain the inverse-impulse response of the concrete. The data for this report include: Multiple target, nondispersive data; single-target, variable-size dispersive data; single-target, variable-depth dispersive data; and single-target, variable transmitted-pulse-width dispersive data. Results of this simulation indicate that data generated by the weights of the adaptive filter, coupled with a two-dimensional, synthetic-aperture focusing technique, successfully generate two-dimensional images of targets within the concrete from modeled data.

  18. Reproductive isolation and local adaptation quantified for a chromosome inversion in a malaria mosquito.

    PubMed

    Ayala, Diego; Guerrero, Rafael F; Kirkpatrick, Mark

    2013-04-01

    Chromosome inversions have long been thought to be involved in speciation and local adaptation. We have little quantitative information, however, about the effects that inversion polymorphisms have on reproductive isolation and viability. Here we provide the first estimates from any organism for the total amount of reproductive isolation associated with an inversion segregating in natural populations. We sampled chromosomes from 751 mosquitoes of the malaria vector Anopheles funestus along a 1421 km transect in Cameroon that traverses savannah, highland, and rainforest ecological zones. We then developed a series of population genetic models that account for selection, migration, and assortative mating, and fit the models to the data using likelihood. Results from the best-fit models suggest there is strong local adaptation, with relative viabilities of homozygotes ranging from 25% to 130% compared to heterozygotes. Viabilities vary qualitatively between regions: the inversion is underdominant in the savannah, whereas in the highlands it is overdominant. The inversion is also implicated in strong assortative mating. In the savannah, the two homozygote forms show 92% reproductive isolation, suggesting that this one inversion can generate most of the genetic barriers needed for speciation.

  19. SU-E-T-555: A Protontherapy Inverse Treatment Planning System Prototype with Linear Energy Transfer (LET) Optimization

    SciTech Connect

    Sanchez-Parcerisa, D; Carabe-Fernandez, A

    2014-06-01

    Purpose: Develop and benchmark an inverse treatment planning system (TPS) for proton radiotherapy integrating fast analytical dose and LET calculations in patient geometries and a dual objective function with both dose and LET components, enabling us to apply optimization techniques to improve the predicted outcome of treatments based on radiobiological models. Methods: The software package was developed in MATLAB and implements a fluence-dose calculation technique based on a pencil beam model for dose calculations and a 3D LET model based on the extension of the LET in the radial direction as a function of the predicted radiological pathway. Both models were benchmarked against commissioning data from our institution, dose calculations performed with a commercial treatment planning system and Monte Carlo simulations. The optimization is based on the adaptive simulated annealing approach . Results: The dose and LET calculations were tested in a water phantom and several real patient treatments. The pass rate for the gamma index analysis (3%/3mm) test was above 90% for all test cases analyzed, and the calculation time was of the order of seconds. The inverse planning module produced plans with a significantly higher mean LET in the target compared to traditional plans, without any loss of target coverage. The clinical relevance of this improvement is under consideration . Conclusion: The developed treatment planning system is a valuable clinical and research tool that enables us to incorporate LET effects into proton radiotherapy planning in a streamlined fashion.

  20. Adaptive path planning in changing environments

    SciTech Connect

    Chen, Pang C.

    1993-10-01

    Path planning needs to be fast to facilitate real-time robot programming. Unfortunately, current planning techniques are still too slow to be effective, as they often require several minutes, if not hours of computation. To overcome this difficulty, we present an adaptive algorithm that uses previous experience to speed up future performance. It is a learning algorithm suitable for incrementally-changing environments such as those encountered in manufacturing of evolving products and waste-site remediation. The algorithm extends our previous work for stationary environments in two directions: For minor environmental change, an object-attached experience abstraction scheme is introduced to increase the flexibility of the learned experience; for major environmental change, an on-demand experience repair scheme is also introduced to retain those experiences that remain valid and useful. In addition to presenting this algorithm, we identify three other variants with different repair strategies. To compare these algorithms, we develop an analytic model to compare the costs and benefits of the corresponding repair processes. Using this model, we formalize the concept of incremental change, and prove the optimality of our proposed algorithm under such change. Empirically, we also characterize the performance curve of each variant, confirm our theoretical optimality results, and demonstrate the practicality of our algorithm.

  1. Forward-Inverse Adaptive Techniques for Reservoir Characterization and Simulation: Theory and Applications

    SciTech Connect

    Doss, S D; Ezzedine, S; Gelinas, R; Chawathe, A

    2001-06-11

    A novel approach called Forward-Inverse Adaptive Techniques (FIAT) for reservoir characterization is developed and applied to three representative exploration cases. Inverse modeling refers to the determination of the entire reservoir permeability under steady state single-phase flow regime, given only field permeability, pressure and production well measurements. FIAT solves the forward and inverse partial differential equations (PDEs) simultaneously by adding a regularization term and filtering pressure gradients. An implicit adaptive-grid, Galerkin, numerical scheme is used to numerically solve the set of PDEs subject to pressure and permeability boundary conditions. Three examples are presented. Results from all three cases demonstrate attainable and reasonably accurate solutions and, more importantly, provide insights into the consequences of data undersampling.

  2. Adaptive divergence in the monkey flower Mimulus guttatus is maintained by a chromosomal inversion

    PubMed Central

    Twyford, Alex D.; Friedman, Jannice

    2015-01-01

    Organisms exhibit an incredible diversity of life history strategies as adaptive responses to environmental variation. The establishment of novel life history strategies involves multilocus polymorphisms, which will be challenging to establish in the face of gene flow and recombination. Theory predicts that adaptive allelic combinations may be maintained and spread if they occur in genomic regions of reduced recombination, such as chromosomal inversion polymorphisms, yet empirical support for this prediction is lacking. Here, we use genomic data to investigate the evolution of divergent adaptive ecotypes of the yellow monkey flower Mimulus guttatus. We show that a large chromosomal inversion polymorphism is the major region of divergence between geographically widespread annual and perennial ecotypes. In contrast, ∼40,000 single nucleotide polymorphisms in collinear regions of the genome show no signal of life history, revealing genomic patterns of diversity have been shaped by localized homogenizing gene flow and large‐scale Pleistocene range expansion. Our results provide evidence for an inversion capturing and protecting loci involved in local adaptation, while also explaining how adaptive divergence can occur with gene flow. PMID:25879251

  3. Adaptive divergence in the monkey flower Mimulus guttatus is maintained by a chromosomal inversion.

    PubMed

    Twyford, Alex D; Friedman, Jannice

    2015-06-01

    Organisms exhibit an incredible diversity of life history strategies as adaptive responses to environmental variation. The establishment of novel life history strategies involves multilocus polymorphisms, which will be challenging to establish in the face of gene flow and recombination. Theory predicts that adaptive allelic combinations may be maintained and spread if they occur in genomic regions of reduced recombination, such as chromosomal inversion polymorphisms, yet empirical support for this prediction is lacking. Here, we use genomic data to investigate the evolution of divergent adaptive ecotypes of the yellow monkey flower Mimulus guttatus. We show that a large chromosomal inversion polymorphism is the major region of divergence between geographically widespread annual and perennial ecotypes. In contrast, ∼40,000 single nucleotide polymorphisms in collinear regions of the genome show no signal of life history, revealing genomic patterns of diversity have been shaped by localized homogenizing gene flow and large-scale Pleistocene range expansion. Our results provide evidence for an inversion capturing and protecting loci involved in local adaptation, while also explaining how adaptive divergence can occur with gene flow.

  4. GNBP domain of Anopheles darlingi: are polymorphic inversions and gene variation related to adaptive evolution?

    PubMed

    Bridi, L C; Rafael, M S

    2016-02-01

    Anopheles darlingi is the main malaria vector in humans in South America. In the Amazon basin, it lives along the banks of rivers and lakes, which responds to the annual hydrological cycle (dry season and rainy season). In these breeding sites, the larvae of this mosquito feed on decomposing organic and microorganisms, which can be pathogenic and trigger the activation of innate immune system pathways, such as proteins Gram-negative binding protein (GNBP). Such environmental changes affect the occurrence of polymorphic inversions especially at the heterozygote frequency, which confer adaptative advantage compared to homozygous inversions. We mapped the GNBP probe to the An. darlingi 2Rd inversion by fluorescent in situ hybridization (FISH), which was a good indicator of the GNBP immune response related to the chromosomal polymorphic inversions and adaptative evolution. To better understand the evolutionary relations and time of divergence of the GNBP of An. darlingi, we compared it with nine other mosquito GNBPs. The results of the phylogenetic analysis of the GNBP sequence between the species of mosquitoes demonstrated three clades. Clade I and II included the GNBPB5 sequence, and clade III the sequence of GNBPB1. Most of these sequences of GNBP analyzed were homologous with that of subfamily B, including that of An. gambiae (87 %), therefore suggesting that GNBP of An. darling belongs to subfamily B. This work helps us understand the role of inversion polymorphism in evolution of An. darlingi.

  5. Adaptive inverse control for rotorcraft vibration reduction. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Jacklin, S. A.

    1985-01-01

    The Least Mean Square (LMS) algorithm is extended to solve the multiple-input, multiple-output problem of alleviating N/Rev helicopter fuselage vibration by means of adaptive inverse control. A frequency domain locally linear model is used to represent the transfer matrix relating the high harmonic pitch control inputs to the harmonic vibration outputs to be controlled. By using the inverse matrix as the controller gain matrix, an adaptive inverse regulator is formed to alleviate the N/Rev vibration. The stability and rate of convergence properties of the extended LMS algorithm are discussed. It is shown that the stability ranges for the elements of the stability gain matrix are directly related to the eigenvalues of the vibration signal information matrix for the learning phase, but not for the control phase. The overall conclusion is that the LMS adaptive inverse control method can form a robust vibration control system, but will require some tuning of the input sensor gains, the stability gain matrix, and the amount of control relaxation to be used. The learning curve of the controller during the learning phase is shown to be quantitatively close to that predicted by averaging the learning curves of the normal modes. It is shown that the best selections of the stability gain matrix elements and the amount of control relaxation is basically a compromise between slow, stable convergence and fast convergence with increased possibility of unstable identification.

  6. Comparison of forward planning with automated inverse planning for three-dimensional conformal radiotherapy of non-small cell lung cancer without IMRT.

    PubMed

    Mendes, Ruheena; Lavrenkov, Konstantin; Bedford, James L; Henrys, Anthony; Ashley, Sue; Brada, Michael

    2006-03-01

    The forward and inverse treatment plans of 10 patients with lung cancer were compared in terms of PTV coverage, sparing of normal lung and time required to generate a plan. The inverse planning produced as good treatment plans as an experienced dosimetrist with considerable reduction in staff time. When translated to other complex sites, inverse non-IMRT planning may have considerable impact on manpower requirements. PMID:16564591

  7. An Adaptive Path Planning Algorithm for Cooperating Unmanned Air Vehicles

    SciTech Connect

    Cunningham, C.T.; Roberts, R.S.

    2000-09-12

    An adaptive path planning algorithm is presented for cooperating Unmanned Air Vehicles (UAVs) that are used to deploy and operate land-based sensor networks. The algorithm employs a global cost function to generate paths for the UAVs, and adapts the paths to exceptions that might occur. Examples are provided of the paths and adaptation.

  8. Adaptive path planning algorithm for cooperating unmanned air vehicles

    SciTech Connect

    Cunningham, C T; Roberts, R S

    2001-02-08

    An adaptive path planning algorithm is presented for cooperating Unmanned Air Vehicles (UAVs) that are used to deploy and operate land-based sensor networks. The algorithm employs a global cost function to generate paths for the UAVs, and adapts the paths to exceptions that might occur. Examples are provided of the paths and adaptation.

  9. A nonlinear model reference adaptive inverse control algorithm with pre-compensator

    NASA Astrophysics Data System (ADS)

    Xiao, Bin; Yang, Tie-Jun; Liu, Zhi-Gang

    2005-12-01

    In this paper, the reduced-order modeling (ROM) technology and its corresponding linear theory are expanded from the linear dynamic system to the nonlinear one, and H ∞ control theory is employed in the frequency domain to design some nonlinear system s pre-compensator in some special way. The adaptive model inverse control (AMIC) theory coping with nonlinear system is improved as well. Such is the model reference adaptive inverse control with pre-compensator (PCMRAIC). The aim of that algorithm is to construct a strategy of control as a whole. As a practical example of the application, the numerical simulation has been given on matlab software packages. The numerical result is given. The proposed strategy realizes the linearization control of nonlinear dynamic system. And it carries out a good performance to deal with the nonlinear system.

  10. Improve earthquake hypocenter using adaptive simulated annealing inversion in regional tectonic, volcano tectonic, and geothermal observation

    SciTech Connect

    Ry, Rexha Verdhora; Nugraha, Andri Dian

    2015-04-24

    Observation of earthquakes is routinely used widely in tectonic activity observation, and also in local scale such as volcano tectonic and geothermal activity observation. It is necessary for determining the location of precise hypocenter which the process involves finding a hypocenter location that has minimum error between the observed and the calculated travel times. When solving this nonlinear inverse problem, simulated annealing inversion method can be applied to such global optimization problems, which the convergence of its solution is independent of the initial model. In this study, we developed own program codeby applying adaptive simulated annealing inversion in Matlab environment. We applied this method to determine earthquake hypocenter using several data cases which are regional tectonic, volcano tectonic, and geothermal field. The travel times were calculated using ray tracing shooting method. We then compared its results with the results using Geiger’s method to analyze its reliability. Our results show hypocenter location has smaller RMS error compared to the Geiger’s result that can be statistically associated with better solution. The hypocenter of earthquakes also well correlated with geological structure in the study area. Werecommend using adaptive simulated annealing inversion to relocate hypocenter location in purpose to get precise and accurate earthquake location.

  11. Novice High School Science Teachers: Lesson Plan Adaptations

    ERIC Educational Resources Information Center

    Scharon, Aracelis Janelle

    2013-01-01

    The Next Generation Science Standards (NRC, 2013) positions teachers as responsible for necessary decision making about how their intended science lesson plan content supports continuous student science learning. Teachers interact with their instructional lesson plans in dynamic and constructive ways. Adapting lesson plans is complex. This process…

  12. A Nonlinear Dynamic Inversion Predictor-Based Model Reference Adaptive Controller for a Generic Transport Model

    NASA Technical Reports Server (NTRS)

    Campbell, Stefan F.; Kaneshige, John T.

    2010-01-01

    Presented here is a Predictor-Based Model Reference Adaptive Control (PMRAC) architecture for a generic transport aircraft. At its core, this architecture features a three-axis, non-linear, dynamic-inversion controller. Command inputs for this baseline controller are provided by pilot roll-rate, pitch-rate, and sideslip commands. This paper will first thoroughly present the baseline controller followed by a description of the PMRAC adaptive augmentation to this control system. Results are presented via a full-scale, nonlinear simulation of NASA s Generic Transport Model (GTM).

  13. Comparative behaviour of the Dynamically Penalized Likelihood algorithm in inverse radiation therapy planning

    NASA Astrophysics Data System (ADS)

    Llacer, Jorge; Solberg, Timothy D.; Promberger, Claus

    2001-10-01

    This paper presents a description of tests carried out to compare the behaviour of five algorithms in inverse radiation therapy planning: (1) The Dynamically Penalized Likelihood (DPL), an algorithm based on statistical estimation theory; (2) an accelerated version of the same algorithm; (3) a new fast adaptive simulated annealing (ASA) algorithm; (4) a conjugate gradient method; and (5) a Newton gradient method. A three-dimensional mathematical phantom and two clinical cases have been studied in detail. The phantom consisted of a U-shaped tumour with a partially enclosed 'spinal cord'. The clinical examples were a cavernous sinus meningioma and a prostate case. The algorithms have been tested in carefully selected and controlled conditions so as to ensure fairness in the assessment of results. It has been found that all five methods can yield relatively similar optimizations, except when a very demanding optimization is carried out. For the easier cases, the differences are principally in robustness, ease of use and optimization speed. In the more demanding case, there are significant differences in the resulting dose distributions. The accelerated DPL emerges as possibly the algorithm of choice for clinical practice. An appendix describes the differences in behaviour between the new ASA method and the one based on a patent by the Nomos Corporation.

  14. Adaptive Surrogate Modeling for Expedited Estimation of Nonlinear Tissue Properties Through Inverse Finite Element Analysis

    PubMed Central

    Halloran, Jason P.; Erdemir, Ahmet

    2011-01-01

    Simulation-based prediction of specimen-specific biomechanical behavior commonly requires inverse analysis using geometrically consistent finite element (FE) models. Optimization drives such analyses but previous studies have highlighted a large computational cost dictated by iterative use of nonlinear FE models. The goal of this study was to evaluate the performance of a local regression-based adaptive surrogate modeling approach to decrease computational cost for both global and local optimization approaches using an inverse FE application. Nonlinear elastic material parameters for patient-specific heel-pad tissue were found, both with and without the surrogate model. Surrogate prediction replaced a FE simulation using local regression of previous simulations when the corresponding error estimate was less than a given tolerance. Performance depended on optimization type and tolerance value. The surrogate reduced local optimization expense up to 68%, but achieved accurate results for only 1 of 20 initial conditions. Conversely, up to a tolerance value of 20 N2, global optimization with the surrogate yielded consistent parameter predictions with a concurrent decrease in computational cost (up to 77%). However, the local optimization method without the surrogate, although sensitive to the initial conditions, was still on average seven times faster than the global approach. Our results help establish guide-lines for setting acceptable tolerance values while using an adaptive surrogate model for inverse FE analysis. Most important, the study demonstrates the benefits of a surrogate modeling approach for intensive FE-based iterative analysis. PMID:21544674

  15. Beyond Reduction: Climate Change Adaptation Planning for Universities and Colleges

    ERIC Educational Resources Information Center

    Owen, Rochelle; Fisher, Erica; McKenzie, Kyle

    2013-01-01

    Purpose: The purpose of this paper is to outline a unique six-step process for the inclusion of climate change adaption goals and strategies in a University Climate Change Plan. Design/methodology/approach: A mixed-method approach was used to gather data on campus climate change vulnerabilities and adaption strategies. A literature review…

  16. Inverse planning for four-dimensional (4D) volumetric modulated arc therapy

    SciTech Connect

    Ma Yunzhi; Chang, Daniel; Keall, Paul; Xie Yiaoqin; Park, Jae-yoon; Suh, Tae-Suk; Xing Lei

    2010-11-15

    Purpose: To develop a 4D volumetric modulated arc therapy (VMAT) inverse planning framework. Methods: 4D VMAT inverse planning aims to derive an aperture and weight modulated arc therapy treatment plan that optimizes the accumulated dose distribution from all gantry angles and breathing phases. Under an assumption that the gantry rotation and patient breathing are synchronized (i.e., there is a functional relationship between the phase of the patient breathing cycle and the beam angle), the authors compute the contribution from different respiration phases through the registration of the phased CT images. The accumulative dose distribution is optimized by iteratively adjusting the aperture shape and weight of each beam through the minimization of the planning objective function. For comparison, traditional 3D VMAT plans are also performed for the two cases and the performance of the proposed technique is demonstrated. Results: A framework for 4D VMAT inverse planning has been proposed. With the consideration of the extra dimension of time in VMAT, a tighter target margin can be achieved with a full duty cycle, which is otherwise not achievable simultaneously by either 3D VMAT optimization or gated VMAT. Conclusions: The 4D VMAT planning formulism proposed here provides useful insight on how the ''time'' dimension can be exploited in rotational arc therapy to maximally compensate for the intrafraction organ motion.

  17. An adaptive importance sampling algorithm for Bayesian inversion with multimodal distributions

    SciTech Connect

    Li, Weixuan; Lin, Guang

    2015-03-21

    Parametric uncertainties are encountered in the simulations of many physical systems, and may be reduced by an inverse modeling procedure that calibrates the simulation results to observations on the real system being simulated. Following Bayes’ rule, a general approach for inverse modeling problems is to sample from the posterior distribution of the uncertain model parameters given the observations. However, the large number of repetitive forward simulations required in the sampling process could pose a prohibitive computational burden. This difficulty is particularly challenging when the posterior is multimodal. We present in this paper an adaptive importance sampling algorithm to tackle these challenges. Two essential ingredients of the algorithm are: 1) a Gaussian mixture (GM) model adaptively constructed as the proposal distribution to approximate the possibly multimodal target posterior, and 2) a mixture of polynomial chaos (PC) expansions, built according to the GM proposal, as a surrogate model to alleviate the computational burden caused by computational-demanding forward model evaluations. In three illustrative examples, the proposed adaptive importance sampling algorithm demonstrates its capabilities of automatically finding a GM proposal with an appropriate number of modes for the specific problem under study, and obtaining a sample accurately and efficiently representing the posterior with limited number of forward simulations.

  18. An adaptive importance sampling algorithm for Bayesian inversion with multimodal distributions

    SciTech Connect

    Li, Weixuan; Lin, Guang

    2015-08-01

    Parametric uncertainties are encountered in the simulations of many physical systems, and may be reduced by an inverse modeling procedure that calibrates the simulation results to observations on the real system being simulated. Following Bayes' rule, a general approach for inverse modeling problems is to sample from the posterior distribution of the uncertain model parameters given the observations. However, the large number of repetitive forward simulations required in the sampling process could pose a prohibitive computational burden. This difficulty is particularly challenging when the posterior is multimodal. We present in this paper an adaptive importance sampling algorithm to tackle these challenges. Two essential ingredients of the algorithm are: 1) a Gaussian mixture (GM) model adaptively constructed as the proposal distribution to approximate the possibly multimodal target posterior, and 2) a mixture of polynomial chaos (PC) expansions, built according to the GM proposal, as a surrogate model to alleviate the computational burden caused by computational-demanding forward model evaluations. In three illustrative examples, the proposed adaptive importance sampling algorithm demonstrates its capabilities of automatically finding a GM proposal with an appropriate number of modes for the specific problem under study, and obtaining a sample accurately and efficiently representing the posterior with limited number of forward simulations.

  19. An adaptive importance sampling algorithm for Bayesian inversion with multimodal distributions

    DOE PAGES

    Li, Weixuan; Lin, Guang

    2015-03-21

    Parametric uncertainties are encountered in the simulations of many physical systems, and may be reduced by an inverse modeling procedure that calibrates the simulation results to observations on the real system being simulated. Following Bayes’ rule, a general approach for inverse modeling problems is to sample from the posterior distribution of the uncertain model parameters given the observations. However, the large number of repetitive forward simulations required in the sampling process could pose a prohibitive computational burden. This difficulty is particularly challenging when the posterior is multimodal. We present in this paper an adaptive importance sampling algorithm to tackle thesemore » challenges. Two essential ingredients of the algorithm are: 1) a Gaussian mixture (GM) model adaptively constructed as the proposal distribution to approximate the possibly multimodal target posterior, and 2) a mixture of polynomial chaos (PC) expansions, built according to the GM proposal, as a surrogate model to alleviate the computational burden caused by computational-demanding forward model evaluations. In three illustrative examples, the proposed adaptive importance sampling algorithm demonstrates its capabilities of automatically finding a GM proposal with an appropriate number of modes for the specific problem under study, and obtaining a sample accurately and efficiently representing the posterior with limited number of forward simulations.« less

  20. An optimal dynamic inversion-based neuro-adaptive approach for treatment of chronic myelogenous leukemia.

    PubMed

    Padhi, Radhakant; Kothari, Mangal

    2007-09-01

    Combining the advanced techniques of optimal dynamic inversion and model-following neuro-adaptive control design, an innovative technique is presented to design an automatic drug administration strategy for effective treatment of chronic myelogenous leukemia (CML). A recently developed nonlinear mathematical model for cell dynamics is used to design the controller (medication dosage). First, a nominal controller is designed based on the principle of optimal dynamic inversion. This controller can treat the nominal model patients (patients who can be described by the mathematical model used here with the nominal parameter values) effectively. However, since the system parameters for a realistic model patient can be different from that of the nominal model patients, simulation studies for such patients indicate that the nominal controller is either inefficient or, worse, ineffective; i.e. the trajectory of the number of cancer cells either shows non-satisfactory transient behavior or it grows in an unstable manner. Hence, to make the drug dosage history more realistic and patient-specific, a model-following neuro-adaptive controller is augmented to the nominal controller. In this adaptive approach, a neural network trained online facilitates a new adaptive controller. The training process of the neural network is based on Lyapunov stability theory, which guarantees both stability of the cancer cell dynamics as well as boundedness of the network weights. From simulation studies, this adaptive control design approach is found to be very effective to treat the CML disease for realistic patients. Sufficient generality is retained in the mathematical developments so that the technique can be applied to other similar nonlinear control design problems as well.

  1. Robustness via Run-Time Adaptation of Contingent Plans

    NASA Technical Reports Server (NTRS)

    Bresina, John L.; Washington, Richard; Norvig, Peter (Technical Monitor)

    2000-01-01

    In this paper, we discuss our approach to making the behavior of planetary rovers more robust for the purpose of increased productivity. Due to the inherent uncertainty in rover exploration, the traditional approach to rover control is conservative, limiting the autonomous operation of the rover and sacrificing performance for safety. Our objective is to increase the science productivity possible within a single uplink by allowing the rover's behavior to be specified with flexible, contingent plans and by employing dynamic plan adaptation during execution. We have deployed a system exhibiting flexible, contingent execution; this paper concentrates on our ongoing efforts on plan adaptation, Plans can be revised in two ways: plan steps may be deleted, with execution continuing with the plan suffix; and the current plan may be merged with an "alternate plan" from an on-board library. The plan revision action is chosen to maximize the expected utility of the plan. Plan merging and action deletion constitute a more conservative general-purpose planning system; in return, our approach is more efficient and more easily verified, two important criteria for deployed rovers.

  2. A covariance-adaptive approach for regularized inversion in linear models

    NASA Astrophysics Data System (ADS)

    Kotsakis, Christopher

    2007-11-01

    The optimal inversion of a linear model under the presence of additive random noise in the input data is a typical problem in many geodetic and geophysical applications. Various methods have been developed and applied for the solution of this problem, ranging from the classic principle of least-squares (LS) estimation to other more complex inversion techniques such as the Tikhonov-Philips regularization, truncated singular value decomposition, generalized ridge regression, numerical iterative methods (Landweber, conjugate gradient) and others. In this paper, a new type of optimal parameter estimator for the inversion of a linear model is presented. The proposed methodology is based on a linear transformation of the classic LS estimator and it satisfies two basic criteria. First, it provides a solution for the model parameters that is optimally fitted (in an average quadratic sense) to the classic LS parameter solution. Second, it complies with an external user-dependent constraint that specifies a priori the error covariance (CV) matrix of the estimated model parameters. The formulation of this constrained estimator offers a unified framework for the description of many regularization techniques that are systematically used in geodetic inverse problems, particularly for those methods that correspond to an eigenvalue filtering of the ill-conditioned normal matrix in the underlying linear model. Our study lies on the fact that it adds an alternative perspective on the statistical properties and the regularization mechanism of many inversion techniques commonly used in geodesy and geophysics, by interpreting them as a family of `CV-adaptive' parameter estimators that obey a common optimal criterion and differ only on the pre-selected form of their error CV matrix under a fixed model design.

  3. An adaptive inverse iteration algorithm using interpolating multiwavelets for structural eigenvalue problems

    NASA Astrophysics Data System (ADS)

    Wang, Youming; Chen, Xuefeng; He, Zhengjia

    2011-02-01

    Structural eigenvalues have been broadly applied in modal analysis, damage detection, vibration control, etc. In this paper, the interpolating multiwavelets are custom designed based on stable completion method to solve structural eigenvalue problems. The operator-orthogonality of interpolating multiwavelets gives rise to highly sparse multilevel stiffness and mass matrices of structural eigenvalue problems and permits the incremental computation of the eigenvalue solution in an efficient manner. An adaptive inverse iteration algorithm using the interpolating multiwavelets is presented to solve structural eigenvalue problems. Numerical examples validate the accuracy and efficiency of the proposed algorithm.

  4. An Adaptive ANOVA-based PCKF for High-Dimensional Nonlinear Inverse Modeling

    SciTech Connect

    LI, Weixuan; Lin, Guang; Zhang, Dongxiao

    2014-02-01

    The probabilistic collocation-based Kalman filter (PCKF) is a recently developed approach for solving inverse problems. It resembles the ensemble Kalman filter (EnKF) in every aspect—except that it represents and propagates model uncertainty by polynomial chaos expansion (PCE) instead of an ensemble of model realizations. Previous studies have shown PCKF is a more efficient alternative to EnKF for many data assimilation problems. However, the accuracy and efficiency of PCKF depends on an appropriate truncation of the PCE series. Having more polynomial chaos bases in the expansion helps to capture uncertainty more accurately but increases computational cost. Bases selection is particularly important for high-dimensional stochastic problems because the number of polynomial chaos bases required to represent model uncertainty grows dramatically as the number of input parameters (random dimensions) increases. In classic PCKF algorithms, the PCE bases are pre-set based on users’ experience. Also, for sequential data assimilation problems, the bases kept in PCE expression remain unchanged in different Kalman filter loops, which could limit the accuracy and computational efficiency of classic PCKF algorithms. To address this issue, we present a new algorithm that adaptively selects PCE bases for different problems and automatically adjusts the number of bases in different Kalman filter loops. The algorithm is based on adaptive functional ANOVA (analysis of variance) decomposition, which approximates a high-dimensional function with the summation of a set of low-dimensional functions. Thus, instead of expanding the original model into PCE, we implement the PCE expansion on these low-dimensional functions, which is much less costly. We also propose a new adaptive criterion for ANOVA that is more suited for solving inverse problems. The new algorithm is tested with different examples and demonstrated great effectiveness in comparison with non-adaptive PCKF and En

  5. An adaptive ANOVA-based PCKF for high-dimensional nonlinear inverse modeling

    SciTech Connect

    Li, Weixuan; Lin, Guang; Zhang, Dongxiao

    2014-02-01

    The probabilistic collocation-based Kalman filter (PCKF) is a recently developed approach for solving inverse problems. It resembles the ensemble Kalman filter (EnKF) in every aspect—except that it represents and propagates model uncertainty by polynomial chaos expansion (PCE) instead of an ensemble of model realizations. Previous studies have shown PCKF is a more efficient alternative to EnKF for many data assimilation problems. However, the accuracy and efficiency of PCKF depends on an appropriate truncation of the PCE series. Having more polynomial chaos basis functions in the expansion helps to capture uncertainty more accurately but increases computational cost. Selection of basis functions is particularly important for high-dimensional stochastic problems because the number of polynomial chaos basis functions required to represent model uncertainty grows dramatically as the number of input parameters (random dimensions) increases. In classic PCKF algorithms, the PCE basis functions are pre-set based on users' experience. Also, for sequential data assimilation problems, the basis functions kept in PCE expression remain unchanged in different Kalman filter loops, which could limit the accuracy and computational efficiency of classic PCKF algorithms. To address this issue, we present a new algorithm that adaptively selects PCE basis functions for different problems and automatically adjusts the number of basis functions in different Kalman filter loops. The algorithm is based on adaptive functional ANOVA (analysis of variance) decomposition, which approximates a high-dimensional function with the summation of a set of low-dimensional functions. Thus, instead of expanding the original model into PCE, we implement the PCE expansion on these low-dimensional functions, which is much less costly. We also propose a new adaptive criterion for ANOVA that is more suited for solving inverse problems. The new algorithm was tested with different examples and demonstrated

  6. Systematic Strategic Planning at a State University: A Case Study of Adapting Corporate Planning Techniques.

    ERIC Educational Resources Information Center

    Aggarwal, Raj

    1987-01-01

    The adaptation of a typical corporate strategic planning process to a midwestern state university is discussed. The university found that an ongoing planning process with a yearly cycle offers several advantages not available with prior approaches, and that strategic planning is a culture that takes time before it becomes pervasive in any…

  7. A Treatment Planning Analysis of Inverse-Planned and Forward-Planned Intensity-Modulated Radiation Therapy in Nasopharyngeal Carcinoma

    SciTech Connect

    Poon, Ian M Xia Ping; Weinberg, Vivien; Sultanem, Khalil; Akazawa, Clayton C.; Akazawa, Pamela C.; Verhey, Lynn; Quivey, Jeanne Marie; Lee, Nancy

    2007-12-01

    Purpose: To compare dose-volume histograms of target volumes and organs at risk in 57 patients with nasopharyngeal carcinoma (NPC) with inverse- (IP) or forward-planned (FP) intensity-modulated radiation treatment (IMRT). Methods and Materials: The DVHs of 57 patients with NPC with IMRT with or without chemotherapy were reviewed. Thirty-one patients underwent IP IMRT, and 26 patients underwent FP IMRT. Treatment goals were to prescribe a minimum dose of 66-70 Gy for gross tumor volume and 59.4 Gy for planning target volume to greater than 95% of the volume. Multiple selected end points were used to compare dose-volume histograms of the targets, including minimum, mean, and maximum doses; percentage of target volume receiving less than 90% (1-V90%), less than 95% (1-V95%), and greater than 105% (1-V105%). Dose-volume histograms of organs at risk were evaluated with characteristic end points. Results: Both planning methods provided excellent target coverage with no statistically significant differences found, although a trend was suggested in favor of improved target coverage with IP IMRT in patients with T3/T4 NPC (p = 0.10). Overall, IP IMRT statistically decreased the dose to the parotid gland, temporomandibular joint, brain stem, and spinal cord overall, whereas IP led to a dose decrease to the middle/inner ear in only the T1/T2 subgroup. Conclusions: Use of IP and FP IMRT can lead to good target coverage while maintaining critical structures within tolerance. The IP IMRT selectively spared these critical organs to a greater degree and should be considered the standard of treatment in patients with NPC, particularly those with T3/T4. The FP IMRT is an effective second option in centers with limited IP IMRT capacity. As a modification of conformal techniques, the human/departmental resources to incorporate FP-IMRT should be nominal.

  8. Inverse planning optimization method for intensity modulated radiation therapy.

    PubMed

    Lan, Yihua; Ren, Haozheng; Li, Cunhua; Min, Zhifang; Wan, Jinxin; Ma, Jianxin; Hung, Chih-Cheng

    2013-10-01

    In order to facilitate the leaf sequencing process in intensity modulated radiation therapy (IMRT), and design of a practical leaf sequencing algorithm, it is an important issue to smooth the planned fluence maps. The objective is to achieve both high-efficiency and high-precision dose delivering by considering characteristics of leaf sequencing process. The key factor which affects total number of monitor units for the leaf sequencing optimization process is the max flow value of the digraph which formulated from the fluence maps. Therefore, we believe that one strategy for compromising dose conformity and total number of monitor units in dose delivery is to balance the dose distribution function and the max flow value mentioned above. However, there are too many paths in the digraph, and we don't know the flow value of which path is the maximum. The maximum flow value among the horizontal paths was selected and used in the objective function of the fluence map optimization to formulate the model. The model is a traditional linear constrained quadratic optimization model which can be solved by interior point method easily. We believe that the smoothed maps from this model are more suitable for leaf sequencing optimization process than other smoothing models. A clinical head-neck case and a prostate case were tested and compared using our proposed model and the smoothing model which is based on the minimization of total variance. The optimization results with the same level of total number of monitor units (TNMU) show that the fluence maps obtained from our model have much better dose performance for the target/non-target region than the maps from total variance based on the smoothing model. This indicates that our model achieves better dose distribution when the algorithm suppresses the TNMU at the same level. Although we have just used the max flow value of the horizontal paths in the diagraph in the objective function, a good balance has been achieved between

  9. Adaptive Stereotactic Body Radiation Therapy Planning for Lung Cancer

    SciTech Connect

    Qin, Yujiao; Zhang, Fan; Yoo, David S.; Kelsey, Chris R.; Yin, Fang-Fang; Cai, Jing

    2013-09-01

    Purpose: To investigate the dosimetric effects of adaptive planning on lung stereotactic body radiation therapy (SBRT). Methods and Materials: Forty of 66 consecutive lung SBRT patients were selected for a retrospective adaptive planning study. CBCT images acquired at each fraction were used for treatment planning. Adaptive plans were created using the same planning parameters as the original CT-based plan, with the goal to achieve comparable comformality index (CI). For each patient, 2 cumulative plans, nonadaptive plan (P{sub NON}) and adaptive plan (P{sub ADP}), were generated and compared for the following organs-at-risks (OARs): cord, esophagus, chest wall, and the lungs. Dosimetric comparison was performed between P{sub NON} and P{sub ADP} for all 40 patients. Correlations were evaluated between changes in dosimetric metrics induced by adaptive planning and potential impacting factors, including tumor-to-OAR distances (d{sub T-OAR}), initial internal target volume (ITV{sub 1}), ITV change (ΔITV), and effective ITV diameter change (Δd{sub ITV}). Results: 34 (85%) patients showed ITV decrease and 6 (15%) patients showed ITV increase throughout the course of lung SBRT. Percentage ITV change ranged from −59.6% to 13.0%, with a mean (±SD) of −21.0% (±21.4%). On average of all patients, P{sub ADP} resulted in significantly (P=0 to .045) lower values for all dosimetric metrics. Δd{sub ITV}/d{sub T-OAR} was found to correlate with changes in dose to 5 cc (ΔD5cc) of esophagus (r=0.61) and dose to 30 cc (ΔD30cc) of chest wall (r=0.81). Stronger correlations between Δd{sub ITV}/d{sub T-OAR} and ΔD30cc of chest wall were discovered for peripheral (r=0.81) and central (r=0.84) tumors, respectively. Conclusions: Dosimetric effects of adaptive lung SBRT planning depend upon target volume changes and tumor-to-OAR distances. Adaptive lung SBRT can potentially reduce dose to adjacent OARs if patients present large tumor volume shrinkage during the treatment.

  10. Guideline adaptation and implementation planning: a prospective observational study

    PubMed Central

    2013-01-01

    Background Adaptation of high-quality practice guidelines for local use has been advanced as an efficient means to improve acceptability and applicability of evidence-informed care. In a pan-Canadian study, we examined how cancer care groups adapted pre-existing guidelines to their unique context and began implementation planning. Methods Using a mixed-methods, case-study design, five cases were purposefully sampled from self-identified groups and followed as they used a structured method and resources for guideline adaptation. Cases received the ADAPTE Collaboration toolkit, facilitation, methodological and logistical support, resources and assistance as required. Documentary and primary data collection methods captured individual case experience, including monthly summaries of meeting and field notes, email/telephone correspondence, and project records. Site visits, process audits, interviews, and a final evaluation forum with all cases contributed to a comprehensive account of participant experience. Results Study cases took 12 to >24 months to complete guideline adaptation. Although participants appreciated the structure, most found the ADAPTE method complex and lacking practical aspects. They needed assistance establishing individual guideline mandate and infrastructure, articulating health questions, executing search strategies, appraising evidence, and achieving consensus. Facilitation was described as a multi-faceted process, a team effort, and an essential ingredient for guideline adaptation. While front-line care providers implicitly identified implementation issues during adaptation, they identified a need to add an explicit implementation planning component. Conclusions Guideline adaptation is a positive initial step toward evidence-informed care, but adaptation (vs. ‘de novo’ development) did not meet expectations for reducing time or resource commitments. Undertaking adaptation is as much about the process (engagement and capacity building) as it

  11. Adaptive path planning: Algorithm and analysis

    SciTech Connect

    Chen, Pang C.

    1995-03-01

    To address the need for a fast path planner, we present a learning algorithm that improves path planning by using past experience to enhance future performance. The algorithm relies on an existing path planner to provide solutions difficult tasks. From these solutions, an evolving sparse work of useful robot configurations is learned to support faster planning. More generally, the algorithm provides a framework in which a slow but effective planner may be improved both cost-wise and capability-wise by a faster but less effective planner coupled with experience. We analyze algorithm by formalizing the concept of improvability and deriving conditions under which a planner can be improved within the framework. The analysis is based on two stochastic models, one pessimistic (on task complexity), the other randomized (on experience utility). Using these models, we derive quantitative bounds to predict the learning behavior. We use these estimation tools to characterize the situations in which the algorithm is useful and to provide bounds on the training time. In particular, we show how to predict the maximum achievable speedup. Additionally, our analysis techniques are elementary and should be useful for studying other types of probabilistic learning as well.

  12. High resolution imaging of the Earth with adaptive full-waveform inversion

    NASA Astrophysics Data System (ADS)

    Morgan, J. V.; Warner, M.; Guasch, L.; Umpleby, A.; Yao, G.; Herrmann, F. J.

    2014-12-01

    Three-dimensional full-waveform inversion (FWI) is a high-resolution, high-fidelity, quantitative, seismic imaging technique that has advanced rapidly within the oil and gas industry. The method involves the iterative improvement of a starting model using a series of local linearized updates to solve the full non-linear inversion problem. During the inversion, forward modeling employs the full two-way three-dimensional heterogeneous anisotropic acoustic or elastic wave equation to predict the observed raw field data, wiggle-for-wiggle, trace-by-trace. The method is computationally demanding; it is highly parallelized, and runs on large multi-core multi-node clusters. A recently developed adaptive version of FWI is able to overcome the requirement for a good starting model and low frequencies in the data, and this opens up the range of datasets and problems to which FWI can be applied. Here, we demonstrate what can be achieved by applying this newly practical technique to high-density 3D seismic datasets acquired to image petroleum targets. We show that the resulting anisotropic p-wave velocity models match in situ measurements in boreholes, reproduce detailed structure observed independently on high-resolution seismic reflection sections, accurately predict the raw seismic data, and simplify and sharpen reverse-time-migrated reflection images of deeper horizons. The velocity models image individual faults, gas clouds, channels, and other geological features with previously unobtainable resolution and clarity. These same benefits can be obtained when this technique is applied to scientific targets provided that the data coverage is adequate in three-dimensions, and that an appropriate range of offsets and azimuths are available. Possible targets range from the water column, ice sheets, and Holocene deposits, through active faults, spreading centres, collision zones, rifted margins, magma plumbing, lower-continental crust, and deep crustal hot zones, to whole

  13. Mission to Mars: Adaptive Identifier for the Solution of Inverse Optical Metrology Tasks

    NASA Astrophysics Data System (ADS)

    Krapivin, Vladimir F.; Varotsos, Costas A.; Christodoulakis, John

    2016-06-01

    A human mission to Mars requires the solution of many problems that mainly linked to the safety of life, the reliable operational control of drinking water as well as health care. The availability of liquid fuels is also an important issue since the existing tools cannot fully provide the required liquid fuels quantities for the mission return journey. This paper presents the development of new methods and technology for reliable, operational, and with high availability chemical analysis of liquid solutions of various types. This technology is based on the employment of optical sensors (such as the multi-channel spectrophotometers or spectroellipsometers and microwave radiometers) and the development of a database of spectral images for typical liquid solutions that could be the objects of life on Mars. This database exploits the adaptive recognition of optical images of liquids using specific algorithms that are based on spectral analysis, cluster analysis and methods for solving the inverse optical metrology tasks.

  14. How much can history constrain adaptive evolution? A real-time evolutionary approach of inversion polymorphisms in Drosophila subobscura.

    PubMed

    Fragata, I; Lopes-Cunha, M; Bárbaro, M; Kellen, B; Lima, M; Santos, M A; Faria, G S; Santos, M; Matos, M; Simões, P

    2014-12-01

    Chromosomal inversions are present in a wide range of animals and plants, having an important role in adaptation and speciation. Although empirical evidence of their adaptive value is abundant, the role of different processes underlying evolution of chromosomal polymorphisms is not fully understood. History and selection are likely to shape inversion polymorphism variation to an extent yet largely unknown. Here, we perform a real-time evolution study addressing the role of historical constraints and selection in the evolution of these polymorphisms. We founded laboratory populations of Drosophila subobscura derived from three locations along the European cline and followed the evolutionary dynamics of inversion polymorphisms throughout the first 40 generations. At the beginning, populations were highly differentiated and remained so throughout generations. We report evidence of positive selection for some inversions, variable between foundations. Signs of negative selection were more frequent, in particular for most cold-climate standard inversions across the three foundations. We found that previously observed convergence at the phenotypic level in these populations was not associated with convergence in inversion frequencies. In conclusion, our study shows that selection has shaped the evolutionary dynamics of inversion frequencies, but doing so within the constraints imposed by previous history. Both history and selection are therefore fundamental to predict the evolutionary potential of different populations to respond to global environmental changes.

  15. Uncertainty Propagation and Quantification using Constrained Coupled Adaptive Forward-Inverse Schemes: Theory and Applications

    NASA Astrophysics Data System (ADS)

    Ryerson, F. J.; Ezzedine, S. M.; Antoun, T.

    2013-12-01

    equation for the distribution of k is solved, provided that Cauchy data are appropriately assigned. In the next stage, only a limited number of passive measurements are provided. In this case, the forward and inverse PDEs are solved simultaneously. This is accomplished by adding regularization terms and filtering the pressure gradients in the inverse problem. Both the forward and the inverse problem are either simultaneously or sequentially coupled and solved using implicit schemes, adaptive mesh refinement, Galerkin finite elements. The final case arises when P, k, and Q data only exist at producing wells. This exceedingly ill posed problem calls for additional constraints on the forward-inverse coupling to insure that the production rates are satisfied at the desired locations. Results from all three cases are presented demonstrating stability and accuracy of the proposed approach and, more importantly, providing some insights into the consequences of data under sampling, uncertainty propagation and quantification. We illustrate the advantages of this novel approach over the common UQ forward drivers on several subsurface energy problems in either porous or fractured or/and faulted reservoirs. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  16. Improving IMRT delivery efficiency with reweighted L1-minimization for inverse planning

    SciTech Connect

    Kim, Hojin; Becker, Stephen; Lee, Rena; Lee, Soonhyouk; Shin, Sukyoung; Candes, Emmanuel; Xing Lei; Li Ruijiang

    2013-07-15

    Purpose: This study presents an improved technique to further simplify the fluence-map in intensity modulated radiation therapy (IMRT) inverse planning, thereby reducing plan complexity and improving delivery efficiency, while maintaining the plan quality.Methods: First-order total-variation (TV) minimization (min.) based on L1-norm has been proposed to reduce the complexity of fluence-map in IMRT by generating sparse fluence-map variations. However, with stronger dose sparing to the critical structures, the inevitable increase in the fluence-map complexity can lead to inefficient dose delivery. Theoretically, L0-min. is the ideal solution for the sparse signal recovery problem, yet practically intractable due to its nonconvexity of the objective function. As an alternative, the authors use the iteratively reweighted L1-min. technique to incorporate the benefits of the L0-norm into the tractability of L1-min. The weight multiplied to each element is inversely related to the magnitude of the corresponding element, which is iteratively updated by the reweighting process. The proposed penalizing process combined with TV min. further improves sparsity in the fluence-map variations, hence ultimately enhancing the delivery efficiency. To validate the proposed method, this work compares three treatment plans obtained from quadratic min. (generally used in clinic IMRT), conventional TV min., and our proposed reweighted TV min. techniques, implemented by a large-scale L1-solver (template for first-order conic solver), for five patient clinical data. Criteria such as conformation number (CN), modulation index (MI), and estimated treatment time are employed to assess the relationship between the plan quality and delivery efficiency.Results: The proposed method yields simpler fluence-maps than the quadratic and conventional TV based techniques. To attain a given CN and dose sparing to the critical organs for 5 clinical cases, the proposed method reduces the number of segments

  17. TH-A-9A-06: Inverse Planning of Gamma Knife Radiosurgery Using Natural Physical Models

    SciTech Connect

    Riofrio, D; Ma, L; Zhou, J; Luan, S

    2014-06-15

    Purpose: Treatment-planning systems rely on computer intensive optimization algorithms in order to provide radiation dose localization. We are investigating a new optimization paradigm based on natural physical modeling and simulations, which tend to evolve in time and find the minimum energy state. In our research, we aim to match physical models with radiation therapy inverse planning problems, where the minimum energy state coincides with the optimal solution. As a prototype study, we have modeled the inverse planning of Gamma Knife radiosurgery using the dynamic interactions between charged particles and demonstrate the potential of the paradigm. Methods: For inverse planning of Gamma Knife radiosurgery: (1) positive charges are uniformly placed on the surface of tumors and critical structures. (2) The Gamma Knife dose kernels of 4mm, 8mm and 16mm radii are modeled as geometric objects with variable charges. (3) The number of shots per each kernel radii is obtained by solving a constrained integer-linear problem. (4) The shots are placed into the tumor volume and move under electrostatic forces. The simulation is performed until internal forces are zero or maximum iterations are reached. (5) Finally, non-negative least squares (NNLS) is used to calculate the beam-on times for each shot. Results: A 3D C-shaped tumor surrounding a spherical critical structure was used for testing the new optimization paradigm. These tests showed that charges spread out evenly covering the tumor while keeping distance from the critical structure, resulting in a high quality plan. Conclusion: We have developed a new paradigm for dose optimization based on the simulation of physical models. As prototype studies, we applied electrostatic models to Gamma Knife radiosurgery and demonstrated the potential of the new paradigm. Further research and fine-tuning of the model are underway. NSF CBET-0853157.

  18. Adaptive Inverse Hyperbolic Tangent Algorithm for Dynamic Contrast Adjustment in Displaying Scenes

    NASA Astrophysics Data System (ADS)

    Yu, Cheng-Yi; Ouyang, Yen-Chieh; Wang, Chuin-Mu; Chang, Chein-I.

    2010-12-01

    Contrast has a great influence on the quality of an image in human visual perception. A poorly illuminated environment can significantly affect the contrast ratio, producing an unexpected image. This paper proposes an Adaptive Inverse Hyperbolic Tangent (AIHT) algorithm to improve the display quality and contrast of a scene. Because digital cameras must maintain the shadow in a middle range of luminance that includes a main object such as a face, a gamma function is generally used for this purpose. However, this function has a severe weakness in that it decreases highlight contrast. To mitigate this problem, contrast enhancement algorithms have been designed to adjust contrast to tune human visual perception. The proposed AIHT determines the contrast levels of an original image as well as parameter space for different contrast types so that not only the original histogram shape features can be preserved, but also the contrast can be enhanced effectively. Experimental results show that the proposed algorithm is capable of enhancing the global contrast of the original image adaptively while extruding the details of objects simultaneously.

  19. Inverse treatment planning for spinal robotic radiosurgery: an international multi-institutional benchmark trial.

    PubMed

    Blanck, Oliver; Wang, Lei; Baus, Wolfgang; Grimm, Jimm; Lacornerie, Thomas; Nilsson, Joakim; Luchkovskyi, Sergii; Palazon Cano, Isabel; Shou, Zhenyu; Ayadi, Myriam; Treuer, Harald; Viard, Romain; Siebert, Frank-Andre; Chan, Mark K H; Hildebrandt, Guido; Dunst, Jürgen; Imhoff, Detlef; Wurster, Stefan; Wolff, Robert; Romanelli, Pantaleo; Lartigau, Eric; Semrau, Robert; Soltys, Scott G; Schweikard, Achim

    2016-01-01

    Stereotactic radiosurgery (SRS) is the accurate, conformal delivery of high-dose radiation to well-defined targets while minimizing normal structure doses via steep dose gradients. While inverse treatment planning (ITP) with computerized optimization algorithms are routine, many aspects of the planning process remain user-dependent. We performed an international, multi-institutional benchmark trial to study planning variability and to analyze preferable ITP practice for spinal robotic radiosurgery. 10 SRS treatment plans were generated for a complex-shaped spinal metastasis with 21 Gy in 3 fractions and tight constraints for spinal cord (V14Gy < 2 cc, V18Gy < 0.1 cc) and target (coverage > 95%). The resulting plans were rated on a scale from 1 to 4 (excellent-poor) in five categories (constraint compliance, optimization goals, low-dose regions, ITP complexity, and clinical acceptability) by a blinded review panel. Additionally, the plans were mathemati-cally rated based on plan indices (critical structure and target doses, conformity, monitor units, normal tissue complication probability, and treatment time) and compared to the human rankings. The treatment plans and the reviewers' rankings varied substantially among the participating centers. The average mean overall rank was 2.4 (1.2-4.0) and 8/10 plans were rated excellent in at least one category by at least one reviewer. The mathematical rankings agreed with the mean overall human rankings in 9/10 cases pointing toward the possibility for sole mathematical plan quality comparison. The final rankings revealed that a plan with a well-balanced trade-off among all planning objectives was preferred for treatment by most par-ticipants, reviewers, and the mathematical ranking system. Furthermore, this plan was generated with simple planning techniques. Our multi-institutional planning study found wide variability in ITP approaches for spinal robotic radiosurgery. The participants', reviewers', and mathematical match

  20. Inverse treatment planning for spinal robotic radiosurgery: an international multi-institutional benchmark trial.

    PubMed

    Blanck, Oliver; Wang, Lei; Baus, Wolfgang; Grimm, Jimm; Lacornerie, Thomas; Nilsson, Joakim; Luchkovskyi, Sergii; Palazon Cano, Isabel; Shou, Zhenyu; Ayadi, Myriam; Treuer, Harald; Viard, Romain; Siebert, Frank-Andre; Chan, Mark K H; Hildebrandt, Guido; Dunst, Jürgen; Imhoff, Detlef; Wurster, Stefan; Wolff, Robert; Romanelli, Pantaleo; Lartigau, Eric; Semrau, Robert; Soltys, Scott G; Schweikard, Achim

    2016-01-01

    Stereotactic radiosurgery (SRS) is the accurate, conformal delivery of high-dose radiation to well-defined targets while minimizing normal structure doses via steep dose gradients. While inverse treatment planning (ITP) with computerized optimization algorithms are routine, many aspects of the planning process remain user-dependent. We performed an international, multi-institutional benchmark trial to study planning variability and to analyze preferable ITP practice for spinal robotic radiosurgery. 10 SRS treatment plans were generated for a complex-shaped spinal metastasis with 21 Gy in 3 fractions and tight constraints for spinal cord (V14Gy < 2 cc, V18Gy < 0.1 cc) and target (coverage > 95%). The resulting plans were rated on a scale from 1 to 4 (excellent-poor) in five categories (constraint compliance, optimization goals, low-dose regions, ITP complexity, and clinical acceptability) by a blinded review panel. Additionally, the plans were mathemati-cally rated based on plan indices (critical structure and target doses, conformity, monitor units, normal tissue complication probability, and treatment time) and compared to the human rankings. The treatment plans and the reviewers' rankings varied substantially among the participating centers. The average mean overall rank was 2.4 (1.2-4.0) and 8/10 plans were rated excellent in at least one category by at least one reviewer. The mathematical rankings agreed with the mean overall human rankings in 9/10 cases pointing toward the possibility for sole mathematical plan quality comparison. The final rankings revealed that a plan with a well-balanced trade-off among all planning objectives was preferred for treatment by most par-ticipants, reviewers, and the mathematical ranking system. Furthermore, this plan was generated with simple planning techniques. Our multi-institutional planning study found wide variability in ITP approaches for spinal robotic radiosurgery. The participants', reviewers', and mathematical match

  1. Evaluation of National Adaptation Planning: A Case Study in Indonesia

    SciTech Connect

    Kawanishi, Masato; Ridwan, Nadia Amelia

    2016-01-01

    The present study aims to evaluate national adaptation planning, using the National Action Plan for Climate Change Adaptation (RAN-API) in Indonesia as a case. In doing so, the current study applies the methodology used in Preston et al. (2011), where a set of 57 adaptation plans from three developed countries was evaluated against 19 planning processes. The same criteria and scoring system were applied to the current study to evaluate RAN-API, both as identified in its document and as viewed by the stakeholders. A desktop review and questionnaires were undertaken to this end. It was found that discrepancies exist between the status of RAN-API as documented and the stakeholders views of some criteria, suggesting that information or knowledge gaps may still exist despite the efforts made for stakeholder engagement. In some of the other criteria, the stakeholders views match the status as identified in the document. Most notably, they both agree that the weakness of RAN-API is related to limited consideration for non-climatic factors. While the development of RAN-API is a critical step taken in the country, the current study finds that there remains room for further improvement. The criteria or indicators to be used to assess the progress of RAN-API as a whole may need to be further elaborated.

  2. Inverse 4D conformal planning for lung SBRT using particle swarm optimization.

    PubMed

    Modiri, A; Gu, X; Hagan, A; Bland, R; Iyengar, P; Timmerman, R; Sawant, A

    2016-08-21

    A critical aspect of highly potent regimens such as lung stereotactic body radiation therapy (SBRT) is to avoid collateral toxicity while achieving planning target volume (PTV) coverage. In this work, we describe four dimensional conformal radiotherapy using a highly parallelizable swarm intelligence-based stochastic optimization technique. Conventional lung CRT-SBRT uses a 4DCT to create an internal target volume and then, using forward-planning, generates a 3D conformal plan. In contrast, we investigate an inverse-planning strategy that uses 4DCT data to create a 4D conformal plan, which is optimized across the three spatial dimensions (3D) as well as time, as represented by the respiratory phase. The key idea is to use respiratory motion as an additional degree of freedom. We iteratively adjust fluence weights for all beam apertures across all respiratory phases considering OAR sparing, PTV coverage and delivery efficiency. To demonstrate proof-of-concept, five non-small-cell lung cancer SBRT patients were retrospectively studied. The 4D optimized plans achieved PTV coverage comparable to the corresponding clinically delivered plans while showing significantly superior OAR sparing ranging from 26% to 83% for D max heart, 10%-41% for D max esophagus, 31%-68% for D max spinal cord and 7%-32% for V 13 lung. PMID:27476472

  3. Inverse 4D conformal planning for lung SBRT using particle swarm optimization

    NASA Astrophysics Data System (ADS)

    Modiri, A.; Gu, X.; Hagan, A.; Bland, R.; Iyengar, P.; Timmerman, R.; Sawant, A.

    2016-08-01

    A critical aspect of highly potent regimens such as lung stereotactic body radiation therapy (SBRT) is to avoid collateral toxicity while achieving planning target volume (PTV) coverage. In this work, we describe four dimensional conformal radiotherapy using a highly parallelizable swarm intelligence-based stochastic optimization technique. Conventional lung CRT-SBRT uses a 4DCT to create an internal target volume and then, using forward-planning, generates a 3D conformal plan. In contrast, we investigate an inverse-planning strategy that uses 4DCT data to create a 4D conformal plan, which is optimized across the three spatial dimensions (3D) as well as time, as represented by the respiratory phase. The key idea is to use respiratory motion as an additional degree of freedom. We iteratively adjust fluence weights for all beam apertures across all respiratory phases considering OAR sparing, PTV coverage and delivery efficiency. To demonstrate proof-of-concept, five non-small-cell lung cancer SBRT patients were retrospectively studied. The 4D optimized plans achieved PTV coverage comparable to the corresponding clinically delivered plans while showing significantly superior OAR sparing ranging from 26% to 83% for D max heart, 10%–41% for D max esophagus, 31%–68% for D max spinal cord and 7%–32% for V 13 lung.

  4. Inverse 4D conformal planning for lung SBRT using particle swarm optimization.

    PubMed

    Modiri, A; Gu, X; Hagan, A; Bland, R; Iyengar, P; Timmerman, R; Sawant, A

    2016-08-21

    A critical aspect of highly potent regimens such as lung stereotactic body radiation therapy (SBRT) is to avoid collateral toxicity while achieving planning target volume (PTV) coverage. In this work, we describe four dimensional conformal radiotherapy using a highly parallelizable swarm intelligence-based stochastic optimization technique. Conventional lung CRT-SBRT uses a 4DCT to create an internal target volume and then, using forward-planning, generates a 3D conformal plan. In contrast, we investigate an inverse-planning strategy that uses 4DCT data to create a 4D conformal plan, which is optimized across the three spatial dimensions (3D) as well as time, as represented by the respiratory phase. The key idea is to use respiratory motion as an additional degree of freedom. We iteratively adjust fluence weights for all beam apertures across all respiratory phases considering OAR sparing, PTV coverage and delivery efficiency. To demonstrate proof-of-concept, five non-small-cell lung cancer SBRT patients were retrospectively studied. The 4D optimized plans achieved PTV coverage comparable to the corresponding clinically delivered plans while showing significantly superior OAR sparing ranging from 26% to 83% for D max heart, 10%-41% for D max esophagus, 31%-68% for D max spinal cord and 7%-32% for V 13 lung.

  5. Inverse 4D conformal planning for lung SBRT using particle swarm optimization

    NASA Astrophysics Data System (ADS)

    Modiri, A.; Gu, X.; Hagan, A.; Bland, R.; Iyengar, P.; Timmerman, R.; Sawant, A.

    2016-08-01

    A critical aspect of highly potent regimens such as lung stereotactic body radiation therapy (SBRT) is to avoid collateral toxicity while achieving planning target volume (PTV) coverage. In this work, we describe four dimensional conformal radiotherapy using a highly parallelizable swarm intelligence-based stochastic optimization technique. Conventional lung CRT-SBRT uses a 4DCT to create an internal target volume and then, using forward-planning, generates a 3D conformal plan. In contrast, we investigate an inverse-planning strategy that uses 4DCT data to create a 4D conformal plan, which is optimized across the three spatial dimensions (3D) as well as time, as represented by the respiratory phase. The key idea is to use respiratory motion as an additional degree of freedom. We iteratively adjust fluence weights for all beam apertures across all respiratory phases considering OAR sparing, PTV coverage and delivery efficiency. To demonstrate proof-of-concept, five non-small-cell lung cancer SBRT patients were retrospectively studied. The 4D optimized plans achieved PTV coverage comparable to the corresponding clinically delivered plans while showing significantly superior OAR sparing ranging from 26% to 83% for D max heart, 10%-41% for D max esophagus, 31%-68% for D max spinal cord and 7%-32% for V 13 lung.

  6. Proliferation as a framework for adaptive planning. Final report

    SciTech Connect

    Adkins, M.A.

    1993-02-22

    Throughout the forty years of the cold war, the military proficiently demonstrated planning, exercising, and employing against weapons of mass destruction -- specifically nuclear weapons. However, this planning has never targeted the spread of those weapons. The four stages of proliferation (supply, demand, indigenous, threatening) provide a framework for using the adaptive planning concept and identifying proactive military objectives. The existence of nuclear technology, command and control of the weapons of mass destruction, associated moral issues, or the value of assured deterrence between two nuclear weapon states are not addressed. Weapons of mass destruction are the example used to examine the stages of proliferation. Once planning for proliferation of weapons of 'mass destruction has been proven effective, this framework can be applied to other types of proliferants such as narcotic trafficking and transfer of conventional/high technology arms.

  7. Adaptive fuzzy control with smooth inverse for nonlinear systems preceded by non-symmetric dead-zone

    NASA Astrophysics Data System (ADS)

    Wang, Xingjian; Wang, Shaoping

    2016-07-01

    In this study, the adaptive output feedback control problem of a class of nonlinear systems preceded by non-symmetric dead-zone is considered. To cope with the possible control signal chattering phenomenon which is caused by non-smooth dead-zone inverse, a new smooth inverse is proposed for non-symmetric dead-zone compensation. For the systematic design procedure of the adaptive fuzzy control algorithm, we combine the backstepping technique and small-gain approach. The Takagi-Sugeno fuzzy logic systems are used to approximate unknown system nonlinearities. The closed-loop stability is studied by using small gain theorem and the closed-loop system is proved to be semi-globally uniformly ultimately bounded. Simulation results indicate that, compared to the algorithm with the non-smooth inverse, the proposed control strategy can achieve better tracking performance and the chattering phenomenon can be avoided effectively.

  8. An efficient algorithm for the inverse problem in elasticity imaging by means of variational r-adaption.

    PubMed

    Arnold, Alexander; Bruhns, Otto T; Mosler, Jörn

    2011-07-21

    A novel finite element formulation suitable for computing efficiently the stiffness distribution in soft biological tissue is presented in this paper. For that purpose, the inverse problem of finite strain hyperelasticity is considered and solved iteratively. In line with Arnold et al (2010 Phys. Med. Biol. 55 2035), the computing time is effectively reduced by using adaptive finite element methods. In sharp contrast to previous approaches, the novel mesh adaption relies on an r-adaption (re-allocation of the nodes within the finite element triangulation). This method allows the detection of material interfaces between healthy and diseased tissue in a very effective manner. The evolution of the nodal positions is canonically driven by the same minimization principle characterizing the inverse problem of hyperelasticity. Consequently, the proposed mesh adaption is variationally consistent. Furthermore, it guarantees that the quality of the numerical solution is improved. Since the proposed r-adaption requires only a relatively coarse triangulation for detecting material interfaces, the underlying finite element spaces are usually not rich enough for predicting the deformation field sufficiently accurately (the forward problem). For this reason, the novel variational r-refinement is combined with the variational h-adaption (Arnold et al 2010) to obtain a variational hr-refinement algorithm. The resulting approach captures material interfaces well (by using r-adaption) and predicts a deformation field in good agreement with that observed experimentally (by using h-adaption).

  9. An efficient algorithm for the inverse problem in elasticity imaging by means of variational r-adaption

    NASA Astrophysics Data System (ADS)

    Arnold, Alexander; Bruhns, Otto T.; Mosler, Jörn

    2011-07-01

    A novel finite element formulation suitable for computing efficiently the stiffness distribution in soft biological tissue is presented in this paper. For that purpose, the inverse problem of finite strain hyperelasticity is considered and solved iteratively. In line with Arnold et al (2010 Phys. Med. Biol. 55 2035), the computing time is effectively reduced by using adaptive finite element methods. In sharp contrast to previous approaches, the novel mesh adaption relies on an r-adaption (re-allocation of the nodes within the finite element triangulation). This method allows the detection of material interfaces between healthy and diseased tissue in a very effective manner. The evolution of the nodal positions is canonically driven by the same minimization principle characterizing the inverse problem of hyperelasticity. Consequently, the proposed mesh adaption is variationally consistent. Furthermore, it guarantees that the quality of the numerical solution is improved. Since the proposed r-adaption requires only a relatively coarse triangulation for detecting material interfaces, the underlying finite element spaces are usually not rich enough for predicting the deformation field sufficiently accurately (the forward problem). For this reason, the novel variational r-refinement is combined with the variational h-adaption (Arnold et al 2010) to obtain a variational hr-refinement algorithm. The resulting approach captures material interfaces well (by using r-adaption) and predicts a deformation field in good agreement with that observed experimentally (by using h-adaption).

  10. Systematic Planning of Adaptation Options for Pluvial Flood Resilience

    NASA Astrophysics Data System (ADS)

    Babovic, Filip; Mijic, Ana; Madani, Kaveh

    2016-04-01

    Different elements of infrastructure and the built environment vary in their ability to quickly adapt to changing circumstances. Furthermore, many of the slowest, and often largest infrastructure adaptations, offer the greatest improvements to system performance. In the context of de-carbonation of individual buildings Brand (1995) identified six potential layers of adaptation based on their renewal times ranging from daily to multi-decadal time scales. Similar layers exist in urban areas with regards to Water Sensitive Urban Design (WSUD) and pluvial flood risk. These layers range from appliances within buildings to changes in the larger urban form. Changes in low-level elements can be quickly implemented, but are limited in effectiveness, while larger interventions occur at a much slower pace but offer greater benefits as a part of systemic change. In the context of urban adaptation this multi-layered approach provides information on how to order urban adaptations. This information helps to identify potential pathways by prioritising relatively quick adaptations to be implemented in the short term while identifying options which require more long term planning with respect to both uncertainty and flexibility. This information is particularly critical in the evolution towards more resilient and water sensitive cities (Brown, 2009). Several potential adaptation options were identified ranging from small to large-scale adaptations. The time needed for the adaptation to be implemented was estimated and curves representing the added drainage capacity per year were established. The total drainage capacity added by each option was then established. This methodology was utilised on a case study in the Cranbrook Catchment in the North East of London. This information was able to provide insight on how to best renew or extend the life of critical ageing infrastructure.

  11. Adaptive forward-inverse modeling of reservoir fluids away from wellbores

    SciTech Connect

    Ziagos, J P; Gelinas, R J; Doss, S K; Nelson, R G

    1999-07-30

    This Final Report contains the deliverables of the DeepLook Phase I project entitled, ''Adaptive Forward-Inverse Modeling of Reservoir Fluids Away from Wellbores''. The deliverables are: (i) a description of 2-D test problem results, analyses, and technical descriptions of the techniques used, (ii) a listing of program setup commands that construct and execute the codes for selected test problems (these commands are in mathematical terminology, which reinforces technical descriptions in the text), and (iii) an evaluation and recommendation regarding continuance of this project, including considerations of possible extensions to 3-D codes, additional technical scope, and budget for the out-years. The far-market objective in this project is to develop advanced technologies that can help locate and enhance the recovery of oil from heterogeneous rock formations. The specific technical objective in Phase I was to develop proof-of-concept of new forward and inverse (F-I) modeling techniques [Gelinas et al, 1998] that seek to enhance estimates (images) of formation permeability distributions and fluid motion away from wellbore volumes. This goes to the heart of improving industry's ability to jointly image reservoir permeability and flow predictions of trapped and recovered oil versus time. The estimation of formation permeability away from borehole measurements is an ''inverse'' problem. It is an inseparable part of modeling fluid flows throughout the reservoir in efforts to increase the efficiency of oil recovery at minimum cost. Classic issues of non-uniqueness, mathematical instability, noise effects, and inadequate numerical solution techniques have historically impeded progress in reservoir parameter estimations. Because information pertaining to fluid and rock properties is always sampled sparsely by wellbore measurements, a successful method for interpolating permeability and fluid data between the measurements must be: (i) physics-based, (ii) conditioned by

  12. Knowledge exchange for climate adaptation planning in western North America

    NASA Astrophysics Data System (ADS)

    Garfin, Gregg; Orr, Barron

    2015-04-01

    In western North America, the combination of sustained drought, rapid ecosystem changes, and land use changes associated with urban population growth has motivated concern among ecosystem managers about the implications of future climate changes for the landscapes which they manage. Through literature review, surveys, and workshop discussions, we assess the process of moving from concern, to planning, to action, with an emphasis on questions, such as: What are the roles of boundary organizations in facilitating knowledge exchange? Which practices lead to effective interactions between scientists, decision-makers, and knowledge brokers? While there is no "one size fits all" science communication method, the co-production of science and policy by research scientists, science translators, and decision-makers, as co-equals, is a resource intensive, but effective practice for moving adaptation planning forward. Constructive approaches make use of alliances with early adopters and opinion leaders, and make strong communication links between predictions, impacts and solutions. Resource managers need information on the basics of regional climate variability and global climate change, region-specific projections of climate changes and impacts, frank discussion of uncertainties, and opportunities for candid exploration of these topics with peers and subject experts. Research scientists play critical roles in adaptation planning discussions, because they assist resource managers in clarifying the cascade of interactions leading to potential impacts and, importantly, because decision-makers want to hear the information straight from the scientists conducting the research, which bolsters credibility. We find that uncertainty, formerly a topic to avoided, forms the foundation for constructive progress in adaptation planning. Candid exploration of the array of uncertainties, including those due to modeling, institutional, policy and economic factors, with practitioners, science

  13. IPIP: A new approach to inverse planning for HDR brachytherapy by directly optimizing dosimetric indices

    SciTech Connect

    Siauw, Timmy; Cunha, Adam; Atamtuerk, Alper; Hsu, I-Chow; Pouliot, Jean; Goldberg, Ken

    2011-07-15

    Purpose: Many planning methods for high dose rate (HDR) brachytherapy require an iterative approach. A set of computational parameters are hypothesized that will give a dose plan that meets dosimetric criteria. A dose plan is computed using these parameters, and if any dosimetric criteria are not met, the process is iterated until a suitable dose plan is found. In this way, the dose distribution is controlled by abstract parameters. The purpose of this study is to develop a new approach for HDR brachytherapy by directly optimizing the dose distribution based on dosimetric criteria. Methods: The authors developed inverse planning by integer program (IPIP), an optimization model for computing HDR brachytherapy dose plans and a fast heuristic for it. They used their heuristic to compute dose plans for 20 anonymized prostate cancer image data sets from patients previously treated at their clinic database. Dosimetry was evaluated and compared to dosimetric criteria. Results: Dose plans computed from IPIP satisfied all given dosimetric criteria for the target and healthy tissue after a single iteration. The average target coverage was 95%. The average computation time for IPIP was 30.1 s on an Intel(R) Core{sup TM}2 Duo CPU 1.67 GHz processor with 3 Gib RAM. Conclusions: IPIP is an HDR brachytherapy planning system that directly incorporates dosimetric criteria. The authors have demonstrated that IPIP has clinically acceptable performance for the prostate cases and dosimetric criteria used in this study, in both dosimetry and runtime. Further study is required to determine if IPIP performs well for a more general group of patients and dosimetric criteria, including other cancer sites such as GYN.

  14. Lessons and challenges from adaptation pathways planning applications

    NASA Astrophysics Data System (ADS)

    Haasnoot, M.; Lawrence, J.; Kwakkel, J. H.; Walker, W.; Timmermans, J.; Bloemen, P.; Thissen, W.

    2015-12-01

    Planning for adaptation to dynamic risks (e.g., because of climate change) is a critical need. The concept of 'adaptive policies' is receiving increasing attention as a way of performing strategic planning that is able to address many of the inherent challenges of uncertainty and dynamic change. Several approaches for developing adaptive policies are available in the literature. One approach, for which several applications already exist, is Dynamic Adaptive Policy Pathways (DAPP). Pathway maps enable policy analysts, decision makers, and stakeholders to recognize potential 'locked-in' situations and to assess the flexibility, robustness, and efficacy of decision alternatives. Most of the applications of DAPP have been in deltas, coastal cities, or floodplains, often within the context of climate change adaptation. In this talk, we describe the DAPP approach and present a framework for designing signposts as adaptation signals, together with an illustrative application for the Rhine River in the Netherlands. We also draw lessons and challenges from pathways applications that differ in environment, culture, and institutional context. For example, the Dutch Delta Programme has used pathways to identify short-term decisions and long-term policy options. In Bangladesh, an application is in its early phase. Steps before generating pathways - such as long- term thinking in multiple possible futures and acknowledging uncertainties - are already a big challenge there. In New Zealand, the 'Sustainable Delta Game' has been used as the catalyst for pathways thinking by two local councils. This has led to its application in decision making for coastal and flood risk management and economic analysis of policy options.

  15. Generation of prostate IMAT plans adaptable to the inter-fractional changes of patient geometry

    NASA Astrophysics Data System (ADS)

    Holubyev, K.; Gainey, M.; Bratengeier, K.; Polat, B.; Flentje, M.

    2014-04-01

    We present the results of 2-Step generation of adaptable IMAT plans for prostate carcinoma cases. The 2-Step IMAT plans show clinical and dosimetric equivalence to the reference SmartArcTM-generated VMAT plans. The 2-Step plans are adapted to inter-fractional changes of prostate-rectum geometry using 2-Step adaptation rules for a cohort of ten adaptation cases. The adapted 2-Step IMAT plans show statistically significant improvement (Wilcoxon 1-tail p < 0.05) of target coverage and of rectum sparing when compared to isocenter relocated plans.

  16. Climate Change Assessment and Adaptation Planning for the Southeast US

    NASA Astrophysics Data System (ADS)

    Georgakakos, A. P.; Yao, H.; Zhang, F.

    2012-12-01

    A climate change assessment is carried out for the Apalachicola-Chattahoochee-Flint River Basin in the southeast US following an integrated water resources assessment and planning framework. The assessment process begins with the development/selection of consistent climate, demographic, socio-economic, and land use/cover scenarios. Historical scenarios and responses are analyzed first to establish baseline conditions. Future climate scenarios are based on GCMs available through the IPCC. Statistical and/or dynamic downscaling of GCM outputs is applied to generate high resolution (12x12 km) atmospheric forcing, such as rainfall, temperature, and ET demand, over the ACF River Basin watersheds. Physically based watershed, aquifer, and estuary models (lumped and distributed) are used to quantify the hydrologic and water quality river basin response to alternative climate and land use/cover scenarios. Demand assessments are carried out for each water sector, for example, water supply for urban, agricultural, and industrial users; hydro-thermal facilities; navigation reaches; and environmental/ecological flow and lake level requirements, aiming to establish aspirational water use targets, performance metrics, and management/adaptation options. Response models for the interconnected river-reservoir-aquifer-estuary system are employed next to assess actual water use levels and other sector outputs under a specific set of hydrologic inputs, demand targets, and management/adaptation options. Adaptive optimization methods are used to generate system-wide management policies conditional on inflow forecasts. The generated information is used to inform stakeholder planning and decision processes aiming to develop consensus on adaptation measures, management strategies, and performance monitoring indicators. The assessment and planning process is driven by stakeholder input and is inherently iterative and sequential.

  17. Inverse planning in the age of digital LINACs: station parameter optimized radiation therapy (SPORT)

    NASA Astrophysics Data System (ADS)

    Xing, Lei; Li, Ruijiang

    2014-03-01

    The last few years have seen a number of technical and clinical advances which give rise to a need for innovations in dose optimization and delivery strategies. Technically, a new generation of digital linac has become available which offers features such as programmable motion between station parameters and high dose-rate Flattening Filter Free (FFF) beams. Current inverse planning methods are designed for traditional machines and cannot accommodate these features of new generation linacs without compromising either dose conformality and/or delivery efficiency. Furthermore, SBRT is becoming increasingly important, which elevates the need for more efficient delivery, improved dose distribution. Here we will give an overview of our recent work in SPORT designed to harness the digital linacs and highlight the essential components of SPORT. We will summarize the pros and cons of traditional beamlet-based optimization (BBO) and direct aperture optimization (DAO) and introduce a new type of algorithm, compressed sensing (CS)-based inverse planning, that is capable of automatically removing the redundant segments during optimization and providing a plan with high deliverability in the presence of a large number of station control points (potentially non-coplanar, non-isocentric, and even multi-isocenters). We show that CS-approach takes the interplay between planning and delivery into account and allows us to balance the dose optimality and delivery efficiency in a controlled way and, providing a viable framework to address various unmet demands of the new generation linacs. A few specific implementation strategies of SPORT in the forms of fixed-gantry and rotational arc delivery are also presented.

  18. Collaborative Adaptation Planning for Water Security: Preliminary Lessons, Challenges, and the Way Forward for Maipo Basin Adaptation Plan, Chile

    NASA Astrophysics Data System (ADS)

    Vicuna, S.; Scott, C. A.; Bonelli, S.; Bustos, E.; Meza, F. J.

    2014-12-01

    The Maipo basin holds 40% of Chile's total population and almost half of the country's Gross Domestic Product. The basin is located in the semiarid central region of the country and, aside from the typical pressures of growth in developing country basins, the Maipo river faces climate change impacts associated with a reduction in total runoff and changes in its seasonality. Surface water is the main water source for human settlements and economic activities including agriculture. In 2012 we started a research project to create a climate variability and climate change adaptation plan for the basin. The pillars of the plan are co-produced by researchers and a Scenario Building Team (SBT) with membership of relevant water and land use stakeholders (including from civil society, public and private sectors) in the basin. Following similar experiences in other regions in the world that have faced the challenges of dealing with long term planning under uncertainty, the project has divided the task of developing the plan into a series of interconnected elements. A critical first component is to work on the desired vision(s) of the basin for the future. In this regards, the "water security" concept has been chosen as a framework that accommodates all objectives of the SBT members. Understanding and quantifying the uncertainties that could affect the future water security of the basin is another critical aspect of the plan. Near and long term climate scenarios are one dimension of these uncertainties that are combined with base development uncertainties such as urban growth scenarios. A third component constructs the models/tools that allows the assessment of impacts on water security that could arise under these scenarios. The final critical component relates to the development of the adaptation measures that could avoid the negative impacts and/or capture the potential opportunities. After two years in the development of the adaptation plan a series of results has been

  19. Parallel three-dimensional magnetotelluric inversion using adaptive finite-element method. Part I: theory and synthetic study

    NASA Astrophysics Data System (ADS)

    Grayver, Alexander V.

    2015-07-01

    This paper presents a distributed magnetotelluric inversion scheme based on adaptive finite-element method (FEM). The key novel aspect of the introduced algorithm is the use of automatic mesh refinement techniques for both forward and inverse modelling. These techniques alleviate tedious and subjective procedure of choosing a suitable model parametrization. To avoid overparametrization, meshes for forward and inverse problems were decoupled. For calculation of accurate electromagnetic (EM) responses, automatic mesh refinement algorithm based on a goal-oriented error estimator has been adopted. For further efficiency gain, EM fields for each frequency were calculated using independent meshes in order to account for substantially different spatial behaviour of the fields over a wide range of frequencies. An automatic approach for efficient initial mesh design in inverse problems based on linearized model resolution matrix was developed. To make this algorithm suitable for large-scale problems, it was proposed to use a low-rank approximation of the linearized model resolution matrix. In order to fill a gap between initial and true model complexities and resolve emerging 3-D structures better, an algorithm for adaptive inverse mesh refinement was derived. Within this algorithm, spatial variations of the imaged parameter are calculated and mesh is refined in the neighborhoods of points with the largest variations. A series of numerical tests were performed to demonstrate the utility of the presented algorithms. Adaptive mesh refinement based on the model resolution estimates provides an efficient tool to derive initial meshes which account for arbitrary survey layouts, data types, frequency content and measurement uncertainties. Furthermore, the algorithm is capable to deliver meshes suitable to resolve features on multiple scales while keeping number of unknowns low. However, such meshes exhibit dependency on an initial model guess. Additionally, it is demonstrated

  20. Numerous strategies but limited implementation guidance in US local adaptation plans

    NASA Astrophysics Data System (ADS)

    Woodruff, Sierra C.; Stults, Missy

    2016-08-01

    Adaptation planning offers a promising approach for identifying and devising solutions to address local climate change impacts. Yet there is little empirical understanding of the content and quality of these plans. We use content analysis to evaluate 44 local adaptation plans in the United States and multivariate regression to examine how plan quality varies across communities. We find that plans draw on multiple data sources to analyse future climate impacts and include a breadth of strategies. Most plans, however, fail to prioritize impacts and strategies or provide detailed implementation processes, raising concerns about whether adaptation plans will translate into on-the-ground reductions in vulnerability. Our analysis also finds that plans authored by the planning department and those that engaged elected officials in the planning process were of higher quality. The results provide important insights for practitioners, policymakers and scientists wanting to improve local climate adaptation planning and action.

  1. SU-E-J-78: Adaptive Planning Workflow in a Pencil Beam Scanning Proton Therapy Center

    SciTech Connect

    Blakey, M; Price, S; Robison, B; Niek, S; Moe, S; Renegar, J; Mark, A; Spenser, W

    2015-06-15

    Purpose: The susceptibility of proton therapy to changes in patient setup and anatomy necessitates an adaptive planning process. With the right planning tools and clinical workflow, an adaptive plan can be created in a timely manner without adding significant workload to the treatment planning staff. Methods: In our center, a weekly QA CT is performed on most patients to assess setup, anatomy change, and tumor response. The QA CT is fused to the treatment planning CT, the contours are transferred via deformable registration, and the plan dose is recalculated on the QA CT. A physicist assesses the dose distribution, and an adaptive plan is requested based on tumor coverage or OAR dose changes. After the physician confirms or alters the deformed contours, a dosimetrist develops an adaptive plan using our TPS adaptation module. The plan is assessed for robustness and is then reviewed by the physician. Patient QA is performed within three days following the first adapted treatment. Results: Of the patients who received QA CTs, 19% required at least one adaptive plan (18.5% H&N, 18.5% brain, 11.1% breast, 14.8% chestwall, 14.8% lung, 18.5% pelvis and 3.8% abdomen). Of these patients, 14% went on a break, while the remainder was treated with the previous plan during the re-planning process. Adaptive plans were performed based on tumor shrinkage, anatomy change or positioning uncertainties for 37.9%, 44.8%, and 17.3% of the patients, respectively. On average, 3 full days are required between the QA CT and the first adapted plan treatment. Conclusion: Adaptive planning is a crucial component of proton therapy and should be applied to any site when the QA CT shows significant deviation from the plan. With an efficient workflow, an adaptive plan can be applied without delaying patient treatment or burdening the dosimetry and medical physics team.

  2. Automatic treatment plan re-optimization for adaptive radiotherapy guided with the initial plan DVHs.

    PubMed

    Li, Nan; Zarepisheh, Masoud; Uribe-Sanchez, Andres; Moore, Kevin; Tian, Zhen; Zhen, Xin; Graves, Yan Jiang; Gautier, Quentin; Mell, Loren; Zhou, Linghong; Jia, Xun; Jiang, Steve

    2013-12-21

    Adaptive radiation therapy (ART) can reduce normal tissue toxicity and/or improve tumor control through treatment adaptations based on the current patient anatomy. Developing an efficient and effective re-planning algorithm is an important step toward the clinical realization of ART. For the re-planning process, manual trial-and-error approach to fine-tune planning parameters is time-consuming and is usually considered unpractical, especially for online ART. It is desirable to automate this step to yield a plan of acceptable quality with minimal interventions. In ART, prior information in the original plan is available, such as dose-volume histogram (DVH), which can be employed to facilitate the automatic re-planning process. The goal of this work is to develop an automatic re-planning algorithm to generate a plan with similar, or possibly better, DVH curves compared with the clinically delivered original plan. Specifically, our algorithm iterates the following two loops. An inner loop is the traditional fluence map optimization, in which we optimize a quadratic objective function penalizing the deviation of the dose received by each voxel from its prescribed or threshold dose with a set of fixed voxel weighting factors. In outer loop, the voxel weighting factors in the objective function are adjusted according to the deviation of the current DVH curves from those in the original plan. The process is repeated until the DVH curves are acceptable or maximum iteration step is reached. The whole algorithm is implemented on GPU for high efficiency. The feasibility of our algorithm has been demonstrated with three head-and-neck cancer IMRT cases, each having an initial planning CT scan and another treatment CT scan acquired in the middle of treatment course. Compared with the DVH curves in the original plan, the DVH curves in the resulting plan using our algorithm with 30 iterations are better for almost all structures. The re-optimization process takes about 30 s using

  3. Automatic treatment plan re-optimization for adaptive radiotherapy guided with the initial plan DVHs

    NASA Astrophysics Data System (ADS)

    Li, Nan; Zarepisheh, Masoud; Uribe-Sanchez, Andres; Moore, Kevin; Tian, Zhen; Zhen, Xin; Jiang Graves, Yan; Gautier, Quentin; Mell, Loren; Zhou, Linghong; Jia, Xun; Jiang, Steve

    2013-12-01

    Adaptive radiation therapy (ART) can reduce normal tissue toxicity and/or improve tumor control through treatment adaptations based on the current patient anatomy. Developing an efficient and effective re-planning algorithm is an important step toward the clinical realization of ART. For the re-planning process, manual trial-and-error approach to fine-tune planning parameters is time-consuming and is usually considered unpractical, especially for online ART. It is desirable to automate this step to yield a plan of acceptable quality with minimal interventions. In ART, prior information in the original plan is available, such as dose-volume histogram (DVH), which can be employed to facilitate the automatic re-planning process. The goal of this work is to develop an automatic re-planning algorithm to generate a plan with similar, or possibly better, DVH curves compared with the clinically delivered original plan. Specifically, our algorithm iterates the following two loops. An inner loop is the traditional fluence map optimization, in which we optimize a quadratic objective function penalizing the deviation of the dose received by each voxel from its prescribed or threshold dose with a set of fixed voxel weighting factors. In outer loop, the voxel weighting factors in the objective function are adjusted according to the deviation of the current DVH curves from those in the original plan. The process is repeated until the DVH curves are acceptable or maximum iteration step is reached. The whole algorithm is implemented on GPU for high efficiency. The feasibility of our algorithm has been demonstrated with three head-and-neck cancer IMRT cases, each having an initial planning CT scan and another treatment CT scan acquired in the middle of treatment course. Compared with the DVH curves in the original plan, the DVH curves in the resulting plan using our algorithm with 30 iterations are better for almost all structures. The re-optimization process takes about 30 s using

  4. Path Planning Algorithms for the Adaptive Sensor Fleet

    NASA Technical Reports Server (NTRS)

    Stoneking, Eric; Hosler, Jeff

    2005-01-01

    The Adaptive Sensor Fleet (ASF) is a general purpose fleet management and planning system being developed by NASA in coordination with NOAA. The current mission of ASF is to provide the capability for autonomous cooperative survey and sampling of dynamic oceanographic phenomena such as current systems and algae blooms. Each ASF vessel is a software model that represents a real world platform that carries a variety of sensors. The OASIS platform will provide the first physical vessel, outfitted with the systems and payloads necessary to execute the oceanographic observations described in this paper. The ASF architecture is being designed for extensibility to accommodate heterogenous fleet elements, and is not limited to using the OASIS platform to acquire data. This paper describes the path planning algorithms developed for the acquisition phase of a typical ASF task. Given a polygonal target region to be surveyed, the region is subdivided according to the number of vessels in the fleet. The subdivision algorithm seeks a solution in which all subregions have equal area and minimum mean radius. Once the subregions are defined, a dynamic programming method is used to find a minimum-time path for each vessel from its initial position to its assigned region. This path plan includes the effects of water currents as well as avoidance of known obstacles. A fleet-level planning algorithm then shuffles the individual vessel assignments to find the overall solution which puts all vessels in their assigned regions in the minimum time. This shuffle algorithm may be described as a process of elimination on the sorted list of permutations of a cost matrix. All these path planning algorithms are facilitated by discretizing the region of interest onto a hexagonal tiling.

  5. Development of a residency program in radiation oncology physics: an inverse planning approach.

    PubMed

    Khan, Rao F H; Dunscombe, Peter B

    2016-03-08

    Over the last two decades, there has been a concerted effort in North America to organize medical physicists' clinical training programs along more structured and formal lines. This effort has been prompted by the Commission on Accreditation of Medical Physics Education Programs (CAMPEP) which has now accredited about 90 residency programs. Initially the accreditation focused on standardized and higher quality clinical physics training; the development of rounded professionals who can function at a high level in a multidisciplinary environment was recognized as a priority of a radiation oncology physics residency only lately. In this report, we identify and discuss the implementation of, and the essential components of, a radiation oncology physics residency designed to produce knowledgeable and effective clinical physicists for today's safety-conscious and collaborative work environment. Our approach is that of inverse planning, by now familiar to all radiation oncology physicists, in which objectives and constraints are identified prior to the design of the program. Our inverse planning objectives not only include those associated with traditional residencies (i.e., clinical physics knowledge and critical clinical skills), but also encompass those other attributes essential for success in a modern radiation therapy clinic. These attributes include formal training in management skills and leadership, teaching and communication skills, and knowledge of error management techniques and patient safety. The constraints in our optimization exercise are associated with the limited duration of a residency and the training resources available. Without compromising the knowledge and skills needed for clinical tasks, we have successfully applied the model to the University of Calgary's two-year residency program. The program requires 3840 hours of overall commitment from the trainee, of which 7%-10% is spent in obtaining formal training in nontechnical "soft skills".

  6. Development of a residency program in radiation oncology physics: an inverse planning approach.

    PubMed

    Khan, Rao F H; Dunscombe, Peter B

    2016-01-01

    Over the last two decades, there has been a concerted effort in North America to organize medical physicists' clinical training programs along more structured and formal lines. This effort has been prompted by the Commission on Accreditation of Medical Physics Education Programs (CAMPEP) which has now accredited about 90 residency programs. Initially the accreditation focused on standardized and higher quality clinical physics training; the development of rounded professionals who can function at a high level in a multidisciplinary environment was recognized as a priority of a radiation oncology physics residency only lately. In this report, we identify and discuss the implementation of, and the essential components of, a radiation oncology physics residency designed to produce knowledgeable and effective clinical physicists for today's safety-conscious and collaborative work environment. Our approach is that of inverse planning, by now familiar to all radiation oncology physicists, in which objectives and constraints are identified prior to the design of the program. Our inverse planning objectives not only include those associated with traditional residencies (i.e., clinical physics knowledge and critical clinical skills), but also encompass those other attributes essential for success in a modern radiation therapy clinic. These attributes include formal training in management skills and leadership, teaching and communication skills, and knowledge of error management techniques and patient safety. The constraints in our optimization exercise are associated with the limited duration of a residency and the training resources available. Without compromising the knowledge and skills needed for clinical tasks, we have successfully applied the model to the University of Calgary's two-year residency program. The program requires 3840 hours of overall commitment from the trainee, of which 7%-10% is spent in obtaining formal training in nontechnical "soft skills". PMID

  7. Applying Utility Functions to Adaptation Planning for Home Automation Applications

    NASA Astrophysics Data System (ADS)

    Bratskas, Pyrros; Paspallis, Nearchos; Kakousis, Konstantinos; Papadopoulos, George A.

    A pervasive computing environment typically comprises multiple embedded devices that may interact together and with mobile users. These users are part of the environment, and they experience it through a variety of devices embedded in the environment. This perception involves technologies which may be heterogeneous, pervasive, and dynamic. Due to the highly dynamic properties of such environments, the software systems running on them have to face problems such as user mobility, service failures, or resource and goal changes which may happen in an unpredictable manner. To cope with these problems, such systems must be autonomous and self-managed. In this chapter we deal with a special kind of a ubiquitous environment, a smart home environment, and introduce a user-preference-based model for adaptation planning. The model, which dynamically forms a set of configuration plans for resources, reasons automatically and autonomously, based on utility functions, on which plan is likely to best achieve the user's goals with respect to resource availability and user needs.

  8. Mixed integer programming improves comprehensibility and plan quality in inverse optimization of prostate HDR brachytherapy.

    PubMed

    Gorissen, Bram L; den Hertog, Dick; Hoffmann, Aswin L

    2013-02-21

    Current inverse treatment planning methods that optimize both catheter positions and dwell times in prostate HDR brachytherapy use surrogate linear or quadratic objective functions that have no direct interpretation in terms of dose-volume histogram (DVH) criteria, do not result in an optimum or have long solution times. We decrease the solution time of the existing linear and quadratic dose-based programming models (LP and QP, respectively) to allow optimizing over potential catheter positions using mixed integer programming. An additional average speed-up of 75% can be obtained by stopping the solver at an early stage, without deterioration of the plan quality. For a fixed catheter configuration, the dwell time optimization model LP solves to optimality in less than 15 s, which confirms earlier results. We propose an iterative procedure for QP that allows us to prescribe the target dose as an interval, while retaining independence between the solution time and the number of dose calculation points. This iterative procedure is comparable in speed to the LP model and produces better plans than the non-iterative QP. We formulate a new dose-volume-based model that maximizes V(100%) while satisfying pre-set DVH criteria. This model optimizes both catheter positions and dwell times within a few minutes depending on prostate volume and number of catheters, optimizes dwell times within 35 s and gives better DVH statistics than dose-based models. The solutions suggest that the correlation between the objective value and the clinical plan quality is weak in the existing dose-based models. PMID:23363622

  9. Adaptive Fuzzy Tracking Control of Nonlinear Systems With Asymmetric Actuator Backlash Based on a New Smooth Inverse.

    PubMed

    Lai, Guanyu; Liu, Zhi; Zhang, Yun; Philip Chen, C L

    2016-06-01

    This paper is concentrated on the problem of adaptive fuzzy tracking control for an uncertain nonlinear system whose actuator is encountered by the asymmetric backlash behavior. First, we propose a new smooth inverse model which can approximate the asymmetric actuator backlash arbitrarily. By applying it, two adaptive fuzzy control scenarios, namely, the compensation-based control scheme and nonlinear decomposition-based control scheme, are then developed successively. It is worth noticing that the first fuzzy controller exhibits a better tracking control performance, although it recourses to a known slope ratio of backlash nonlinearity. The second one further removes the restriction, and also gets a desirable control performance. By the strict Lyapunov argument, both adaptive fuzzy controllers guarantee that the output tracking error is convergent to an adjustable region of zero asymptotically, while all the signals remain semiglobally uniformly ultimately bounded. Lastly, two comparative simulations are conducted to verify the effectiveness of the proposed fuzzy controllers. PMID:27187937

  10. Cerebellum as a forward but not inverse model in visuomotor adaptation task: a tDCS-based and modeling study.

    PubMed

    Yavari, Fatemeh; Mahdavi, Shirin; Towhidkhah, Farzad; Ahmadi-Pajouh, Mohammad-Ali; Ekhtiari, Hamed; Darainy, Mohammad

    2016-04-01

    Despite several pieces of evidence, which suggest that the human brain employs internal models for motor control and learning, the location of these models in the brain is not yet clear. In this study, we used transcranial direct current stimulation (tDCS) to manipulate right cerebellar function, while subjects adapt to a visuomotor task. We investigated the effect of this manipulation on the internal forward and inverse models by measuring two kinds of behavior: generalization of training in one direction to neighboring directions (as a proxy for inverse models) and localization of the hand position after movement without visual feedback (as a proxy for forward model). The experimental results showed no effect of cerebellar tDCS on generalization, but significant effect on localization. These observations support the idea that the cerebellum is a possible brain region for internal forward, but not inverse model formation. We also used a realistic human head model to calculate current density distribution in the brain. The result of this model confirmed the passage of current through the cerebellum. Moreover, to further explain some observed experimental results, we modeled the visuomotor adaptation process with the help of a biologically inspired method known as population coding. The effect of tDCS was also incorporated in the model. The results of this modeling study closely match our experimental data and provide further evidence in line with the idea that tDCS manipulates FM's function in the cerebellum.

  11. Inverse theory resolution analysis in planning radio science gravity investigations of icy moons

    NASA Astrophysics Data System (ADS)

    Ganse, A.; Vance, S.

    2014-12-01

    The nature of an icy satellite's interior relates fundamentally to its composition, thermal structure, formation and evolution history, and prospects for supporting life. Gravity measurements via radio Doppler information during spacecraft flybys constitute an important tool to infer gross interior structure. Liquid water and ice layers have previously been inferred for the interiors of Jupiter's icy satellites Europa, Ganymede, and Callisto on the basis of magnetic field measurements by the Galileo probe. On Europa and Callisto induced magnetic field signatures measured by the Galileo probe provided strong evidence for an ionic aqueous ocean. Among the chief goals of the proposed Europa Clipper mission in returning to Europa is characterizing the structure of the moon's icy shell. A geophysical inverse theory resolution analysis can be calculated at the pre-measurement mission planning stage, contributing planning considerations from the point of view of the search for mass anomalies in the ice shell (meteorites or diapiric upwellings) or near the H2O/rock interface (seamounts). The analysis allows us to assess the location-varying resolution of an icy moon's interior density anomaly distribution that can be estimated from radio Doppler measurements. It considers the tradeoff between the resolution of the estimated density anomaly distribution and its estimation uncertainty, and investigates issues in distinguishing between ocean anomalies (e.g., seamounts) and mass anomalies within or near the surface of the ice layer. We apply the resolution analysis to proposed Europa Clipper trajectories and past Galileo spacecraft trajectories about Europa and Ganymede.

  12. Inverse Planned High-Dose-Rate Brachytherapy for Locoregionally Advanced Cervical Cancer: 4-Year Outcomes

    SciTech Connect

    Tinkle, Christopher L.; Weinberg, Vivian; Chen, Lee-May; Littell, Ramey; Cunha, J. Adam M.; Sethi, Rajni A.; Chan, John K.; Hsu, I-Chow

    2015-08-01

    Purpose: Evaluate the efficacy and toxicity of image guided brachytherapy using inverse planning simulated annealing (IPSA) high-dose-rate brachytherapy (HDRB) boost for locoregionally advanced cervical cancer. Methods and Materials: From December 2003 through September 2009, 111 patients with primary cervical cancer were treated definitively with IPSA-planned HDRB boost (28 Gy in 4 fractions) after external radiation at our institution. We performed a retrospective review of our experience using image guided brachytherapy. Of the patients, 70% had a tumor size >4 cm, 38% had regional nodal disease, and 15% had clinically evident distant metastasis, including nonregional nodal disease, at the time of diagnosis. Surgical staging involving pelvic lymph node dissection was performed in 15% of patients, and 93% received concurrent cisplatin-based chemotherapy. Toxicities are reported according to the Common Terminology Criteria for Adverse Events version 4.0 guidelines. Results: With a median follow-up time of 42 months (range, 3-84 months), no acute or late toxicities of grade 4 or higher were observed, and grade 3 toxicities (both acute and late) developed in 8 patients (1 constitutional, 1 hematologic, 2 genitourinary, 4 gastrointestinal). The 4-year Kaplan-Meier estimate of late grade 3 toxicity was 8%. Local recurrence developed in 5 patients (4 to 9 months after HDRB), regional recurrence in 3 (6, 16, and 72 months after HDRB), and locoregional recurrence in 1 (4 months after HDR boost). The 4-year estimates of local, locoregional, and distant control of disease were 94.0%, 91.9%, and 69.1%, respectively. The overall and disease-free survival rates at 4 years were 64.3% (95% confidence interval [CI] of 54%-73%) and 61.0% (95% CI, 51%-70%), respectively. Conclusions: Definitive radiation by use of inverse planned HDRB boost for locoregionally advanced cervical cancer is well tolerated and achieves excellent local control of disease. However, overall

  13. Adaptive dynamic inversion robust control for BTT missile based on wavelet neural network

    NASA Astrophysics Data System (ADS)

    Li, Chuanfeng; Wang, Yongji; Deng, Zhixiang; Wu, Hao

    2009-10-01

    A new nonlinear control strategy incorporated the dynamic inversion method with wavelet neural networks is presented for the nonlinear coupling system of Bank-to-Turn(BTT) missile in reentry phase. The basic control law is designed by using the dynamic inversion feedback linearization method, and the online learning wavelet neural network is used to compensate the inversion error due to aerodynamic parameter errors, modeling imprecise and external disturbance in view of the time-frequency localization properties of wavelet transform. Weights adjusting laws are derived according to Lyapunov stability theory, which can guarantee the boundedness of all signals in the whole system. Furthermore, robust stability of the closed-loop system under this tracking law is proved. Finally, the six degree-of-freedom(6DOF) simulation results have shown that the attitude angles can track the anticipant command precisely under the circumstances of existing external disturbance and in the presence of parameter uncertainty. It means that the dependence on model by dynamic inversion method is reduced and the robustness of control system is enhanced by using wavelet neural network(WNN) to reconstruct inversion error on-line.

  14. A novel adaptive Cuckoo search for optimal query plan generation.

    PubMed

    Gomathi, Ramalingam; Sharmila, Dhandapani

    2014-01-01

    The emergence of multiple web pages day by day leads to the development of the semantic web technology. A World Wide Web Consortium (W3C) standard for storing semantic web data is the resource description framework (RDF). To enhance the efficiency in the execution time for querying large RDF graphs, the evolving metaheuristic algorithms become an alternate to the traditional query optimization methods. This paper focuses on the problem of query optimization of semantic web data. An efficient algorithm called adaptive Cuckoo search (ACS) for querying and generating optimal query plan for large RDF graphs is designed in this research. Experiments were conducted on different datasets with varying number of predicates. The experimental results have exposed that the proposed approach has provided significant results in terms of query execution time. The extent to which the algorithm is efficient is tested and the results are documented. PMID:25215330

  15. A novel adaptive Cuckoo search for optimal query plan generation.

    PubMed

    Gomathi, Ramalingam; Sharmila, Dhandapani

    2014-01-01

    The emergence of multiple web pages day by day leads to the development of the semantic web technology. A World Wide Web Consortium (W3C) standard for storing semantic web data is the resource description framework (RDF). To enhance the efficiency in the execution time for querying large RDF graphs, the evolving metaheuristic algorithms become an alternate to the traditional query optimization methods. This paper focuses on the problem of query optimization of semantic web data. An efficient algorithm called adaptive Cuckoo search (ACS) for querying and generating optimal query plan for large RDF graphs is designed in this research. Experiments were conducted on different datasets with varying number of predicates. The experimental results have exposed that the proposed approach has provided significant results in terms of query execution time. The extent to which the algorithm is efficient is tested and the results are documented.

  16. A Novel Adaptive Cuckoo Search for Optimal Query Plan Generation

    PubMed Central

    Gomathi, Ramalingam; Sharmila, Dhandapani

    2014-01-01

    The emergence of multiple web pages day by day leads to the development of the semantic web technology. A World Wide Web Consortium (W3C) standard for storing semantic web data is the resource description framework (RDF). To enhance the efficiency in the execution time for querying large RDF graphs, the evolving metaheuristic algorithms become an alternate to the traditional query optimization methods. This paper focuses on the problem of query optimization of semantic web data. An efficient algorithm called adaptive Cuckoo search (ACS) for querying and generating optimal query plan for large RDF graphs is designed in this research. Experiments were conducted on different datasets with varying number of predicates. The experimental results have exposed that the proposed approach has provided significant results in terms of query execution time. The extent to which the algorithm is efficient is tested and the results are documented. PMID:25215330

  17. A Meta-Analysis of Urban Climate Change Adaptation Planning in the U.S.

    EPA Science Inventory

    The concentration of people, infrastructure, and ecosystem services in urban areas make them prime sites for climate change adaptation. While advances have been made in developing frameworks for adaptation planning and identifying both real and potential barriers to action, empir...

  18. Using adaptive sampling and triangular meshes for the processing and inversion of potential field data

    NASA Astrophysics Data System (ADS)

    Foks, Nathan Leon

    The interpretation of geophysical data plays an important role in the analysis of potential field data in resource exploration industries. Two categories of interpretation techniques are discussed in this thesis; boundary detection and geophysical inversion. Fault or boundary detection is a method to interpret the locations of subsurface boundaries from measured data, while inversion is a computationally intensive method that provides 3D information about subsurface structure. My research focuses on these two aspects of interpretation techniques. First, I develop a method to aid in the interpretation of faults and boundaries from magnetic data. These processes are traditionally carried out using raster grid and image processing techniques. Instead, I use unstructured meshes of triangular facets that can extract inferred boundaries using mesh edges. Next, to address the computational issues of geophysical inversion, I develop an approach to reduce the number of data in a data set. The approach selects the data points according to a user specified proxy for its signal content. The approach is performed in the data domain and requires no modification to existing inversion codes. This technique adds to the existing suite of compressive inversion algorithms. Finally, I develop an algorithm to invert gravity data for an interfacing surface using an unstructured mesh of triangular facets. A pertinent property of unstructured meshes is their flexibility at representing oblique, or arbitrarily oriented structures. This flexibility makes unstructured meshes an ideal candidate for geometry based interface inversions. The approaches I have developed provide a suite of algorithms geared towards large-scale interpretation of potential field data, by using an unstructured representation of both the data and model parameters.

  19. Temporal adaptability and the inverse relationship to sensitivity: a parameter identification model.

    PubMed

    Langley, Keith

    2005-01-01

    Following a prolonged period of visual adaptation to a temporally modulated sinusoidal luminance pattern, the threshold contrast of a similar visual pattern is elevated. The adaptive elevation in threshold contrast is selective for spatial frequency, may saturate at low adaptor contrast, and increases as a function of the spatio-temporal frequency of the adapting signal. A model for signal extraction that is capable of explaining these threshold contrast effects of adaptation is proposed. Contrast adaptation in the model is explained by the identification of the parameters of an environmental model: the autocorrelation function of the visualized signal. The proposed model predicts that the adaptability of threshold contrast is governed by unpredicted signal variations present in the visual signal, and thus represents an internal adjustment by the visual system that takes into account these unpredicted signal variations given the additional possibility for signal corruption by additive noise.

  20. Dosimetric aspects of inverse-planned modulated-arc total-body irradiation

    SciTech Connect

    Held, Mareike; Kirby, Neil; Morin, Olivier; Pouliot, Jean

    2012-08-15

    Purpose: To develop optimal beam parameters and to verify the dosimetric aspects of the recently developed modulated-arc total-body irradiation (MATBI) technique, which delivers an inverse-planned dose to the entire body using gantry rotation. Methods: The patient is positioned prone and supine underneath the gantry at about 2 m source-to-surface distance (SSD). Then, up to 28 beams irradiate the patient from different gantry angles. Based on full-body computed-tomography (CT) images of the patient, the weight of each beam is optimized, using inverse planning, to create a uniform body dose. This study investigates how to best simulate patients and the ideal beam setup parameters, such as field size, number of beams, and beam geometry, for treatment time and dose homogeneity. In addition, three anthropomorphic water phantoms were constructed and utilized to verify the accuracy of dose delivery, with both diode array and ion chamber measurements. Furthermore, to improve the accuracy of the new technique, a beam model is created specifically for the extended-SSD positioning for MATBI. Results: Low dose CT scans can be utilized for dose calculations without affecting the accuracy. The largest field size of 40 Multiplication-Sign 40 cm{sup 2} was found to deliver the most uniform dose in the least amount of time. Moreover, a higher number of beams improves dose homogeneity. The average dose discrepancy between ion chamber measurements and extended-SSD beam model calculations was 1.2%, with the largest discrepancy being 3.2%. This average dose discrepancy was 1.4% with the standard beam model for delivery at isocenter. Conclusions: The optimum beam setup parameters, regarding dose uniformity and treatment duration, are laid out for modulated-arc TBI. In addition, the presented dose measurements show that these treatments can be delivered accurately. These measurements also indicated that a new beam model did not significantly improve the accuracy of dose calculations

  1. Efficient IMRT inverse planning with a new L1-solver: template for first-order conic solver

    NASA Astrophysics Data System (ADS)

    Kim, Hojin; Suh, Tae-Suk; Lee, Rena; Xing, Lei; Li, Ruijiang

    2012-07-01

    Intensity modulated radiation therapy (IMRT) inverse planning using total-variation (TV) regularization has been proposed to reduce the complexity of fluence maps and facilitate dose delivery. Conventionally, the optimization problem with L-1 norm is solved with quadratic programming (QP), which is time consuming and memory expensive due to the second-order Newton update. This study proposes to use a new algorithm, template for first-order conic solver (TFOCS), for fast and memory-efficient optimization in IMRT inverse planning. The TFOCS utilizes dual-variable updates and first-order approaches for TV minimization without the need to compute and store the enlarged Hessian matrix required for Newton update in the QP technique. To evaluate the effectiveness and efficiency of the proposed method, two clinical cases were used for IMRT inverse planning: a head and neck case and a prostate case. For comparison, the conventional QP-based method for the TV form was adopted to solve the fluence map optimization problem in the above two cases. The convergence criteria and algorithm parameters were selected to achieve similar dose conformity for a fair comparison between the two methods. Compared with conventional QP-based approach, the proposed TFOCS-based method shows a remarkable improvement in computational efficiency for fluence map optimization, while maintaining the conformal dose distribution. Compared with QP-based algorithms, the computational speed using TFOCS for fluence optimization is increased by a factor of 4 to 6, and at the same time the memory requirement is reduced by a factor of 3 to 4. Therefore, TFOCS provides an effective, fast and memory-efficient method for IMRT inverse planning. The unique features of the approach should be particularly important in inverse planning involving a large number of beams, such as in VMAT and dense angularly sampled and sparse intensity modulated radiation therapy (DASSIM-RT).

  2. A radiobiology-based inverse treatment planning method for optimisation of permanent l-125 prostate implants in focal brachytherapy

    NASA Astrophysics Data System (ADS)

    Haworth, Annette; Mears, Christopher; Betts, John M.; Reynolds, Hayley M.; Tack, Guido; Leo, Kevin; Williams, Scott; Ebert, Martin A.

    2016-01-01

    Treatment plans for ten patients, initially treated with a conventional approach to low dose-rate brachytherapy (LDR, 145 Gy to entire prostate), were compared with plans for the same patients created with an inverse-optimisation planning process utilising a biologically-based objective. The ‘biological optimisation’ considered a non-uniform distribution of tumour cell density through the prostate based on known and expected locations of the tumour. Using dose planning-objectives derived from our previous biological-model validation study, the volume of the urethra receiving 125% of the conventional prescription (145 Gy) was reduced from a median value of 64% to less than 8% whilst maintaining high values of TCP. On average, the number of planned seeds was reduced from 85 to less than 75. The robustness of plans to random seed displacements needs to be carefully considered when using contemporary seed placement techniques. We conclude that an inverse planning approach to LDR treatments, based on a biological objective, has the potential to maintain high rates of tumour control whilst minimising dose to healthy tissue. In future, the radiobiological model will be informed using multi-parametric MRI to provide a personalised medicine approach.

  3. A Peak Power Reduction Method with Adaptive Inversion of Clustered Parity-Carriers in BCH-Coded OFDM Systems

    NASA Astrophysics Data System (ADS)

    Muta, Osamu; Akaiwa, Yoshihiko

    In this paper, we propose a simple peak power reduction (PPR) method based on adaptive inversion of parity-check block of codeword in BCH-coded OFDM system. In the proposed method, the entire parity-check block of the codeword is adaptively inversed by multiplying weighting factors (WFs) so as to minimize PAPR of the OFDM signal, symbol-by-symbol. At the receiver, these WFs are estimated based on the property of BCH decoding. When the primitive BCH code with single error correction such as (31,26) code is used, to estimate the WFs, the proposed method employs a significant bit protection method which assigns a significant bit to the best subcarrier selected among all possible subcarriers. With computer simulation, when (31,26), (31,21) and (32,21) BCH codes are employed, PAPR of the OFDM signal at the CCDF (Complementary Cumulative Distribution Function) of 10-4 is reduced by about 1.9, 2.5 and 2.5dB by applying the PPR method, while achieving the BER performance comparable to the case with the perfect WF estimation in exponentially decaying 12-path Rayleigh fading condition.

  4. Linkage disequilibrium network analysis (LDna) gives a global view of chromosomal inversions, local adaptation and geographic structure.

    PubMed

    Kemppainen, Petri; Knight, Christopher G; Sarma, Devojit K; Hlaing, Thaung; Prakash, Anil; Maung Maung, Yan Naung; Somboon, Pradya; Mahanta, Jagadish; Walton, Catherine

    2015-09-01

    Recent advances in sequencing allow population-genomic data to be generated for virtually any species. However, approaches to analyse such data lag behind the ability to generate it, particularly in nonmodel species. Linkage disequilibrium (LD, the nonrandom association of alleles from different loci) is a highly sensitive indicator of many evolutionary phenomena including chromosomal inversions, local adaptation and geographical structure. Here, we present linkage disequilibrium network analysis (LDna), which accesses information on LD shared between multiple loci genomewide. In LD networks, vertices represent loci, and connections between vertices represent the LD between them. We analysed such networks in two test cases: a new restriction-site-associated DNA sequence (RAD-seq) data set for Anopheles baimaii, a Southeast Asian malaria vector; and a well-characterized single nucleotide polymorphism (SNP) data set from 21 three-spined stickleback individuals. In each case, we readily identified five distinct LD network clusters (single-outlier clusters, SOCs), each comprising many loci connected by high LD. In A. baimaii, further population-genetic analyses supported the inference that each SOC corresponds to a large inversion, consistent with previous cytological studies. For sticklebacks, we inferred that each SOC was associated with a distinct evolutionary phenomenon: two chromosomal inversions, local adaptation, population-demographic history and geographic structure. LDna is thus a useful exploratory tool, able to give a global overview of LD associated with diverse evolutionary phenomena and identify loci potentially involved. LDna does not require a linkage map or reference genome, so it is applicable to any population-genomic data set, making it especially valuable for nonmodel species. PMID:25573196

  5. Linkage disequilibrium network analysis (LDna) gives a global view of chromosomal inversions, local adaptation and geographic structure.

    PubMed

    Kemppainen, Petri; Knight, Christopher G; Sarma, Devojit K; Hlaing, Thaung; Prakash, Anil; Maung Maung, Yan Naung; Somboon, Pradya; Mahanta, Jagadish; Walton, Catherine

    2015-09-01

    Recent advances in sequencing allow population-genomic data to be generated for virtually any species. However, approaches to analyse such data lag behind the ability to generate it, particularly in nonmodel species. Linkage disequilibrium (LD, the nonrandom association of alleles from different loci) is a highly sensitive indicator of many evolutionary phenomena including chromosomal inversions, local adaptation and geographical structure. Here, we present linkage disequilibrium network analysis (LDna), which accesses information on LD shared between multiple loci genomewide. In LD networks, vertices represent loci, and connections between vertices represent the LD between them. We analysed such networks in two test cases: a new restriction-site-associated DNA sequence (RAD-seq) data set for Anopheles baimaii, a Southeast Asian malaria vector; and a well-characterized single nucleotide polymorphism (SNP) data set from 21 three-spined stickleback individuals. In each case, we readily identified five distinct LD network clusters (single-outlier clusters, SOCs), each comprising many loci connected by high LD. In A. baimaii, further population-genetic analyses supported the inference that each SOC corresponds to a large inversion, consistent with previous cytological studies. For sticklebacks, we inferred that each SOC was associated with a distinct evolutionary phenomenon: two chromosomal inversions, local adaptation, population-demographic history and geographic structure. LDna is thus a useful exploratory tool, able to give a global overview of LD associated with diverse evolutionary phenomena and identify loci potentially involved. LDna does not require a linkage map or reference genome, so it is applicable to any population-genomic data set, making it especially valuable for nonmodel species.

  6. 76 FR 12945 - Instructions for Implementing Climate Change Adaptation Planning in Accordance With Executive...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-09

    ... expected to implement them as part of their compliance with E.O. 13514. Authority: E.O. 13514, 74 FR 52117... QUALITY Instructions for Implementing Climate Change Adaptation Planning in Accordance With Executive... Adaptation Planning Implementing Instructions. SUMMARY: The Chair of the Council on Environmental...

  7. Adapting to climate change through local municipal planning: barriers and challenges

    SciTech Connect

    Preston, Benjamin L

    2011-01-01

    Municipal planning represents a key avenue for local adaptation, but is subject to recognised constraints. To date, these constraints have focused on simplistic factors such as limited resources and lack of information. In this paper we argue that this focus has obscured a wider set of constraints which need to be acknowledged and addressed if adaptation is likely to advance through municipal planning. Although these recognised constraints are relevant, we argue that what underpins these issues are more fundamental challenges affecting local, placed-based planning by drawing on the related field of community-based environmental planning (CBEP). In considering a wider set of constraints to practical attempts towards adaptation, the paper considers planning based on a case study of three municipalities in Sydney, Australia in 2008. The results demonstrate that climate adaptation was widely accepted as an important issue for planning conducted by local governments. However, it was yet to be embedded in planning practice which retained a strong mitigation bias in relation to climate change. In considering the case study, we draw attention to factors thus far under-acknowledged in the climate adaptation literature. These include leadership, institutional context and competing planning agendas. These factors can serve as constraints or enabling mechanisms for achieving climate adaptation depending upon how they are exploited in any given situation. The paper concludes that, through addressing these issues, local, place-based planning can play a greater role in achieving climate adaptation.

  8. Improving our legacy: Incorporation of adaptive management into state wildlife action plans

    USGS Publications Warehouse

    Fontaine, J.J.

    2011-01-01

    The loss of biodiversity is a mounting concern, but despite numerous attempts there are few large scale conservation efforts that have proven successful in reversing current declines. Given the challenge of biodiversity conservation, there is a need to develop strategic conservation plans that address species declines even with the inherent uncertainty in managing multiple species in complex environments. In 2002, the State Wildlife Grant program was initiated to fulfill this need, and while not explicitly outlined by Congress follows the fundamental premise of adaptive management, 'Learning by doing'. When action is necessary, but basic biological information and an understanding of appropriate management strategies are lacking, adaptive management enables managers to be proactive in spite of uncertainty. However, regardless of the strengths of adaptive management, the development of an effective adaptive management framework is challenging. In a review of 53 State Wildlife Action Plans, I found a keen awareness by planners that adaptive management was an effective method for addressing biodiversity conservation, but the development and incorporation of explicit adaptive management approaches within each plan remained elusive. Only ???25% of the plans included a framework for how adaptive management would be implemented at the project level within their state. There was, however, considerable support across plans for further development and implementation of adaptive management. By furthering the incorporation of adaptive management principles in conservation plans and explicitly outlining the decision making process, states will be poised to meet the pending challenges to biodiversity conservation. ?? 2010 .

  9. Direct and Inverse Problems of Item Pool Design for Computerized Adaptive Testing

    ERIC Educational Resources Information Center

    Belov, Dmitry I.; Armstrong, Ronald D.

    2009-01-01

    The recent literature on computerized adaptive testing (CAT) has developed methods for creating CAT item pools from a large master pool. Each CAT pool is designed as a set of nonoverlapping forms reflecting the skill levels of an assumed population of test takers. This article presents a Monte Carlo method to obtain these CAT pools and discusses…

  10. Inversion for Refractivity Parameters Using a Dynamic Adaptive Cuckoo Search with Crossover Operator Algorithm.

    PubMed

    Zhang, Zhihua; Sheng, Zheng; Shi, Hanqing; Fan, Zhiqiang

    2016-01-01

    Using the RFC technique to estimate refractivity parameters is a complex nonlinear optimization problem. In this paper, an improved cuckoo search (CS) algorithm is proposed to deal with this problem. To enhance the performance of the CS algorithm, a parameter dynamic adaptive operation and crossover operation were integrated into the standard CS (DACS-CO). Rechenberg's 1/5 criteria combined with learning factor were used to control the parameter dynamic adaptive adjusting process. The crossover operation of genetic algorithm was utilized to guarantee the population diversity. The new hybrid algorithm has better local search ability and contributes to superior performance. To verify the ability of the DACS-CO algorithm to estimate atmospheric refractivity parameters, the simulation data and real radar clutter data are both implemented. The numerical experiments demonstrate that the DACS-CO algorithm can provide an effective method for near-real-time estimation of the atmospheric refractivity profile from radar clutter. PMID:27212938

  11. Inversion for Refractivity Parameters Using a Dynamic Adaptive Cuckoo Search with Crossover Operator Algorithm.

    PubMed

    Zhang, Zhihua; Sheng, Zheng; Shi, Hanqing; Fan, Zhiqiang

    2016-01-01

    Using the RFC technique to estimate refractivity parameters is a complex nonlinear optimization problem. In this paper, an improved cuckoo search (CS) algorithm is proposed to deal with this problem. To enhance the performance of the CS algorithm, a parameter dynamic adaptive operation and crossover operation were integrated into the standard CS (DACS-CO). Rechenberg's 1/5 criteria combined with learning factor were used to control the parameter dynamic adaptive adjusting process. The crossover operation of genetic algorithm was utilized to guarantee the population diversity. The new hybrid algorithm has better local search ability and contributes to superior performance. To verify the ability of the DACS-CO algorithm to estimate atmospheric refractivity parameters, the simulation data and real radar clutter data are both implemented. The numerical experiments demonstrate that the DACS-CO algorithm can provide an effective method for near-real-time estimation of the atmospheric refractivity profile from radar clutter.

  12. Inversion for Refractivity Parameters Using a Dynamic Adaptive Cuckoo Search with Crossover Operator Algorithm

    PubMed Central

    Zhang, Zhihua; Sheng, Zheng; Shi, Hanqing; Fan, Zhiqiang

    2016-01-01

    Using the RFC technique to estimate refractivity parameters is a complex nonlinear optimization problem. In this paper, an improved cuckoo search (CS) algorithm is proposed to deal with this problem. To enhance the performance of the CS algorithm, a parameter dynamic adaptive operation and crossover operation were integrated into the standard CS (DACS-CO). Rechenberg's 1/5 criteria combined with learning factor were used to control the parameter dynamic adaptive adjusting process. The crossover operation of genetic algorithm was utilized to guarantee the population diversity. The new hybrid algorithm has better local search ability and contributes to superior performance. To verify the ability of the DACS-CO algorithm to estimate atmospheric refractivity parameters, the simulation data and real radar clutter data are both implemented. The numerical experiments demonstrate that the DACS-CO algorithm can provide an effective method for near-real-time estimation of the atmospheric refractivity profile from radar clutter. PMID:27212938

  13. Multiscale viscoacoustic waveform inversion with the second generation wavelet transform and adaptive time-space domain finite-difference method

    NASA Astrophysics Data System (ADS)

    Ren, Zhiming; Liu, Yang; Zhang, Qunshan

    2014-05-01

    Full waveform inversion (FWI) has the potential to provide preferable subsurface model parameters. The main barrier of its applications to real seismic data is heavy computational amount. Numerical modelling methods are involved in both forward modelling and backpropagation of wavefield residuals, which spend most of computational time in FWI. We develop a time-space domain finite-difference (FD) method and adaptive variable-length spatial operator scheme in numerical simulation of viscoacoustic equation and extend them into the viscoacoustic FWI. Compared with conventional FD methods, different operator lengths are adopted for different velocities and quality factors, which can reduce the amount of computation without reducing accuracy. Inversion algorithms also play a significant role in FWI. In conventional single-scale methods, it is likely to converge to local minimums especially when the initial model is far from the real model. To tackle the problem, we introduce the second generation wavelet transform to implement the multiscale FWI. Compared to other multiscale methods, our method has advantages of ease of implementation and better time-frequency local analysis ability. The L2 norm is widely used in FWI and gives invalid model estimates when the data is contaminated with strong non-uniform noises. We apply the L1-norm and the Huber-norm criteria in the time-domain FWI to improve its antinoise ability. Our strategies have been successfully applied in synthetic experiments to both onshore and offshore reflection seismic data. The results of the viscoacoustic Marmousi example indicate that our new FWI scheme consumes smaller computer resources. In addition, the viscoacoustic Overthrust example shows its better convergence and more reasonable velocity and quality factor structures. All these results demonstrate that our method can improve inversion accuracy and computational efficiency of FWI.

  14. Exploring equivalence domain in nonlinear inverse problems using Covariance Matrix Adaption Evolution Strategy (CMAES) and random sampling

    NASA Astrophysics Data System (ADS)

    Grayver, Alexander V.; Kuvshinov, Alexey V.

    2016-05-01

    This paper presents a methodology to sample equivalence domain (ED) in nonlinear partial differential equation (PDE)-constrained inverse problems. For this purpose, we first applied state-of-the-art stochastic optimization algorithm called Covariance Matrix Adaptation Evolution Strategy (CMAES) to identify low-misfit regions of the model space. These regions were then randomly sampled to create an ensemble of equivalent models and quantify uncertainty. CMAES is aimed at exploring model space globally and is robust on very ill-conditioned problems. We show that the number of iterations required to converge grows at a moderate rate with respect to number of unknowns and the algorithm is embarrassingly parallel. We formulated the problem by using the generalized Gaussian distribution. This enabled us to seamlessly use arbitrary norms for residual and regularization terms. We show that various regularization norms facilitate studying different classes of equivalent solutions. We further show how performance of the standard Metropolis-Hastings Markov chain Monte Carlo algorithm can be substantially improved by using information CMAES provides. This methodology was tested by using individual and joint inversions of magneotelluric, controlled-source electromagnetic (EM) and global EM induction data.

  15. Acute small bowel toxicity and preoperative chemoradiotherapy for rectal cancer: Investigating dose-volume relationships and role for inverse planning

    SciTech Connect

    Tho, Lye Mun . E-mail: l.tho@beatson.gla.ac.uk; Glegg, Martin; Paterson, Jennifer; Yap, Christina; MacLeod, Alice; McCabe, Marie; McDonald, Alexander C.

    2006-10-01

    Purpose: The relationship between volume of irradiated small bowel (VSB) and acute toxicity in rectal cancer radiotherapy is poorly quantified, particularly in patients receiving concurrent preoperative chemoradiotherapy. Using treatment planning data, we studied a series of such patients. Methods and Materials: Details of 41 patients with locally advanced rectal cancer were reviewed. All received 45 Gy in 25 fractions over 5 weeks, 3-4 fields three-dimensional conformal radiotherapy with daily 5-fluorouracil and folinic acid during Weeks 1 and 5. Toxicity was assessed prospectively in a weekly clinic. Using computed tomography planning software, the VSB was determined at 5 Gy dose intervals (V{sub 5}, V{sub 1}, etc.). Eight patients with maximal VSB had dosimetry and radiobiological modeling outcomes compared between inverse and conformal three-dimensional planning. Results: VSB correlated strongly with diarrheal severity at every dose level (p < 0.03), with strongest correlation at lowest doses. Median VSB differed significantly between patients experiencing Grade 0-1 and Grade 2-4 diarrhea (p {<=} 0.05). No correlation was found with anorexia, nausea, vomiting, abdominal cramps, age, body mass index, sex, tumor position, or number of fields. Analysis of 8 patients showed that inverse planning reduced median dose to small bowel by 5.1 Gy (p = 0.008) and calculated late normal tissue complication probability (NTCP) by 67% (p = 0.016). We constructed a model using mathematical analysis to predict for acute diarrhea occurring at V{sub 5} and V{sub 15}. Conclusions: A strong dose-volume relationship exists between VSB and acute diarrhea at all dose levels during preoperative chemoradiotherapy. Our constructed model may be useful in predicting toxicity, and this has been derived without the confounding influence of surgical excision on bowel function. Inverse planning can reduce calculated dose to small bowel and late NTCP, and its clinical role warrants further

  16. On the role of model-based monitoring for adaptive planning under uncertainty

    NASA Astrophysics Data System (ADS)

    Raso, Luciano; Kwakkel, Jan; Timmermans, Jos; Haasnoot, Mariolijn

    2016-04-01

    Adaptive plans, designed to anticipate and respond to an unfolding uncertain future, have found a fertile application domain in the planning of deltas that are exposed to rapid socioeconomic development and climate change. Adaptive planning, under the moniker of adaptive delta management, is used in the Dutch Delta Program for developing a nation-wide plan to prepare for uncertain climate change and socio-economic developments. Scientifically, adaptive delta management relies heavily on Dynamic Adaptive Policy Pathways. Currently, in the Netherlands the focus is shifting towards implementing the adaptive delta plan. This shift is especially relevant because the efficacy of adaptive plans hinges on monitoring on-going developments and ensuring that actions are indeed taken if and when necessary. In the design of an effective monitoring system for an adaptive plan, three challenges have to be confronted: • Shadow of the past: The development of adaptive plans and the design of their monitoring system relies heavily on current knowledge of the system, and current beliefs about plausible future developments. A static monitoring system is therefore exposed to the exact same uncertainties one tries to address through adaptive planning. • Inhibition of learning: Recent applications of adaptive planning tend to overlook the importance of learning and new information, and fail to account for this explicitly in the design of adaptive plans. • Challenge of surprise: Adaptive policies are designed in light of the current foreseen uncertainties. However, developments that are not considered during the design phase as being plausible could still substantially affect the performance of adaptive policies. The shadow of the past, the inhibition of learning, and the challenge of surprise taken together suggest that there is a need for redesigning the concepts of monitoring and evaluation to support the implementation of adaptive plans. Innovations from control theory

  17. Cautious but committed: moving toward adaptive planning and operation strategies for renewable energy's wildlife implications.

    PubMed

    Köppel, Johann; Dahmen, Marie; Helfrich, Jennifer; Schuster, Eva; Bulling, Lea

    2014-10-01

    Wildlife planning for renewable energy must cope with the uncertainties of potential wildlife impacts. Unfortunately, the environmental policies which instigate renewable energy and those which protect wildlife are not coherently aligned-creating a green versus green dilemma. Thus, climate mitigation efforts trigger renewable energy development, but then face substantial barriers from biodiversity protection instruments and practices. This article briefly reviews wind energy and wildlife interactions, highlighting the lively debated effects on bats. Today, planning and siting of renewable energy are guided by the precautionary principle in an attempt to carefully address wildlife challenges. However, this planning attitude creates limitations as it struggles to negotiate the aforementioned green versus green dilemma. More adaptive planning and management strategies and practices hold the potential to reconcile these discrepancies to some degree. This adaptive approach is discussed using facets of case studies from policy, planning, siting, and operational stages of wind energy in Germany and the United States, with one case showing adaptive planning in action for solar energy as well. This article attempts to highlight the benefits of more adaptive approaches as well as the possible shortcomings, such as reduced planning security for renewable energy developers. In conclusion, these studies show that adaptive planning and operation strategies can be designed to supplement and enhance the precautionary principle in wildlife planning for green energy. PMID:25096164

  18. Cautious but committed: moving toward adaptive planning and operation strategies for renewable energy's wildlife implications.

    PubMed

    Köppel, Johann; Dahmen, Marie; Helfrich, Jennifer; Schuster, Eva; Bulling, Lea

    2014-10-01

    Wildlife planning for renewable energy must cope with the uncertainties of potential wildlife impacts. Unfortunately, the environmental policies which instigate renewable energy and those which protect wildlife are not coherently aligned-creating a green versus green dilemma. Thus, climate mitigation efforts trigger renewable energy development, but then face substantial barriers from biodiversity protection instruments and practices. This article briefly reviews wind energy and wildlife interactions, highlighting the lively debated effects on bats. Today, planning and siting of renewable energy are guided by the precautionary principle in an attempt to carefully address wildlife challenges. However, this planning attitude creates limitations as it struggles to negotiate the aforementioned green versus green dilemma. More adaptive planning and management strategies and practices hold the potential to reconcile these discrepancies to some degree. This adaptive approach is discussed using facets of case studies from policy, planning, siting, and operational stages of wind energy in Germany and the United States, with one case showing adaptive planning in action for solar energy as well. This article attempts to highlight the benefits of more adaptive approaches as well as the possible shortcomings, such as reduced planning security for renewable energy developers. In conclusion, these studies show that adaptive planning and operation strategies can be designed to supplement and enhance the precautionary principle in wildlife planning for green energy.

  19. Adaptive planning using megavoltage fan-beam CT for radiation therapy with testicular shielding

    SciTech Connect

    Yadav, Poonam; Kozak, Kevin; Tolakanahalli, Ranjini; Ramasubramanian, V.; Paliwal, Bhudatt R.; Welsh, James S.; Rong, Yi

    2012-07-01

    This study highlights the use of adaptive planning to accommodate testicular shielding in helical tomotherapy for malignancies of the proximal thigh. Two cases of young men with large soft tissue sarcomas of the proximal thigh are presented. After multidisciplinary evaluation, preoperative radiation therapy was recommended. Both patients were referred for sperm banking and lead shields were used to minimize testicular dose during radiation therapy. To minimize imaging artifacts, kilovoltage CT (kVCT) treatment planning was conducted without shielding. Generous hypothetical contours were generated on each 'planning scan' to estimate the location of the lead shield and generate a directionally blocked helical tomotherapy plan. To ensure the accuracy of each plan, megavoltage fan-beam CT (MVCT) scans were obtained at the first treatment and adaptive planning was performed to account for lead shield placement. Two important regions of interest in these cases were femurs and femoral heads. During adaptive planning for the first patient, it was observed that the virtual lead shield contour on kVCT planning images was significantly larger than the actual lead shield used for treatment. However, for the second patient, it was noted that the size of the virtual lead shield contoured on the kVCT image was significantly smaller than the actual shield size. Thus, new adaptive plans based on MVCT images were generated and used for treatment. The planning target volume was underdosed up to 2% and had higher maximum doses without adaptive planning. In conclusion, the treatment of the upper thigh, particularly in young men, presents several clinical challenges, including preservation of gonadal function. In such circumstances, adaptive planning using MVCT can ensure accurate dose delivery even in the presence of high-density testicular shields.

  20. The dosimetric impact of inversely optimized arc radiotherapy plan modulation for real-time dynamic MLC tracking delivery

    SciTech Connect

    Falk, Marianne; Larsson, Tobias; Keall, Paul; Chul Cho, Byung; Aznar, Marianne; Korreman, Stine; Poulsen, Per; Munck af Rosenschoeld, Per

    2012-03-15

    Purpose: Real-time dynamic multileaf collimator (MLC) tracking for management of intrafraction tumor motion can be challenging for highly modulated beams, as the leaves need to travel far to adjust for target motion perpendicular to the leaf travel direction. The plan modulation can be reduced by using a leaf position constraint (LPC) that reduces the difference in the position of adjacent MLC leaves in the plan. The purpose of this study was to investigate the impact of the LPC on the quality of inversely optimized arc radiotherapy plans and the effect of the MLC motion pattern on the dosimetric accuracy of MLC tracking delivery. Specifically, the possibility of predicting the accuracy of MLC tracking delivery based on the plan modulation was investigated. Methods: Inversely optimized arc radiotherapy plans were created on CT-data of three lung cancer patients. For each case, five plans with a single 358 deg. arc were generated with LPC priorities of 0 (no LPC), 0.25, 0.5, 0.75, and 1 (highest possible LPC), respectively. All the plans had a prescribed dose of 2 Gy x 30, used 6 MV, a maximum dose rate of 600 MU/min and a collimator angle of 45 deg. or 315 deg. To quantify the plan modulation, an average adjacent leaf distance (ALD) was calculated by averaging the mean adjacent leaf distance for each control point. The linear relationship between the plan quality [i.e., the calculated dose distributions and the number of monitor units (MU)] and the LPC was investigated, and the linear regression coefficient as well as a two tailed confidence level of 95% was used in the evaluation. The effect of the plan modulation on the performance of MLC tracking was tested by delivering the plans to a cylindrical diode array phantom moving with sinusoidal motion in the superior-inferior direction with a peak-to-peak displacement of 2 cm and a cycle time of 6 s. The delivery was adjusted to the target motion using MLC tracking, guided in real-time by an infrared optical system

  1. Climate change adaptation frameworks: an evaluation of plans for coastal Suffolk, UK

    NASA Astrophysics Data System (ADS)

    Armstrong, J.; Wilby, R.; Nicholls, R. J.

    2015-11-01

    This paper asserts that three principal frameworks for climate change adaptation can be recognised in the literature: scenario-led (SL), vulnerability-led (VL) and decision-centric (DC) frameworks. A criterion is developed to differentiate these frameworks in recent adaptation projects. The criterion features six key hallmarks as follows: (1) use of climate model information; (2) analysis of metrics/units; (3) socio-economic knowledge; (4) stakeholder engagement; (5) adaptation of implementation mechanisms; (6) tier of adaptation implementation. The paper then tests the validity of this approach using adaptation projects on the Suffolk coast, UK. Fourteen adaptation plans were identified in an online survey. They were analysed in relation to the hallmarks outlined above and assigned to an adaptation framework. The results show that while some adaptation plans are primarily SL, VL or DC, the majority are hybrid, showing a mixture of DC/VL and DC/SL characteristics. Interestingly, the SL/VL combination is not observed, perhaps because the DC framework is intermediate and attempts to overcome weaknesses of both SL and VL approaches. The majority (57 %) of adaptation projects generated a risk assessment or advice notes. Further development of this type of framework analysis would allow better guidance on approaches for organisations when implementing climate change adaptation initiatives, and other similar proactive long-term planning.

  2. Climate change adaptation frameworks: an evaluation of plans for coastal, Suffolk, UK

    NASA Astrophysics Data System (ADS)

    Armstrong, J.; Wilby, R.; Nicholls, R. J.

    2015-06-01

    This paper asserts that three principal frameworks for climate change adaptation can be recognised in the literature: Scenario-Led (SL), Vulnerability-Led (VL) and Decision-Centric (DC) frameworks. A criterion is developed to differentiate these frameworks in recent adaptation projects. The criterion features six key hallmarks as follows: (1) use of climate model information; (2) analysis metrics/units; (3) socio-economic knowledge; (4) stakeholder engagement; (5) adaptation implementation mechanisms; (6) tier of adaptation implementation. The paper then tests the validity of this approach using adaptation projects on the Suffolk coast, UK. Fourteen adaptation plans were identified in an online survey. They were analysed in relation to the hallmarks outlined above and assigned to an adaptation framework. The results show that while some adaptation plans are primarily SL, VL or DC, the majority are hybrid showing a mixture of DC/VL and DC/SL characteristics. Interestingly, the SL/VL combination is not observed, perhaps because the DC framework is intermediate and attempts to overcome weaknesses of both SL and VL approaches. The majority (57 %) of adaptation projects generated a risk assessment or advice notes. Further development of this type of framework analysis would allow better guidance on approaches for organisations when implementing climate change adaptation initiatives, and other similar proactive long-term planning.

  3. An error function minimization approach for the inverse problem of adaptive mirrors tuning

    NASA Astrophysics Data System (ADS)

    Vannoni, Maurizio; Yang, Fan; Siewert, Frank; Sinn, Harald

    2014-09-01

    Adaptive x-ray optics are more and more used in synchrotron beamlines, and it is probable that they will be considered for the future high-power free-electron laser sources, as the European XFEL now under construction in Hamburg, or similar projects now in discussion. These facilities will deliver a high power x-ray beam, with an expected high heat load delivered on the optics. For this reason, bendable mirrors are required to actively compensate the resulting wavefront distortion. On top of that, the mirror could have also intrinsic surface defects, as polishing errors or mounting stresses. In order to be able to correct the mirror surface with a high precision to maintain its challenging requirements, the mirror surface is usually characterized with a high accuracy metrology to calculate the actuators pulse functions and to assess its initial shape. After that, singular value decomposition (SVD) is used to find the signals to be applied into the actuators, to reach the desired surface deformation or correction. But in some cases this approach could be not robust enough for the needed performance. We present here a comparison between the classical SVD method and an error function minimization based on root-mean-square calculation. Some examples are provided, using a simulation of the European XFEL mirrors design as a case of study, and performances of the algorithms are evaluated in order to reach the ultimate quality in different scenarios. The approach could be easily generalized to other situations as well.

  4. Linking population, fertility, and family planning with adaptation to climate change: perspectives from Ethiopia.

    PubMed

    Rovin, Kimberly; Hardee, Karen; Kidanu, Aklilu

    2013-09-01

    Global climate change is felt disproportionately in the world's most economically disadvantaged countries. As adaption to an evolving climate becomes increasingly salient on national and global scales, it is important to assess how people at the local-level are already coping with changes. Understanding local responses to climate change is essential for helping countries to construct strategies to bolster resilience to current and future effects. This qualitative research investigated responses to climate change in Ethiopia; specifically, how communities react to and cope with climate variation, which groups are most vulnerable, and the role of family planning in increasing resilience. Participants were highly aware of changing climate effects, impacts of rapid population growth, and the need for increased access to voluntary family planning. Identification of family planning as an important adaptation strategy supports the inclusion of rights-based voluntary family planning and reproductive health into local and national climate change adaptation plans.

  5. Designing monitoring programs in an adaptive management context for regional multiple species conservation plans

    USGS Publications Warehouse

    Atkinson, A.J.; Trenham, P.C.; Fisher, R.N.; Hathaway, S.A.; Johnson, B.S.; Torres, S.G.; Moore, Y.C.

    2004-01-01

    critical management uncertainties; and 3) implementing long-term monitoring and adaptive management. Ultimately, the success of regional conservation planning depends on the ability of monitoring programs to confront the challenges of adaptively managing and monitoring complex ecosystems and diverse arrays of sensitive species.

  6. Two Teachers' Thoughtful Adaptations during Planning and Instruction and the Relationship to Student Agency & Teacher Visioning

    ERIC Educational Resources Information Center

    Vaughn, Margaret

    2010-01-01

    Despite the appealing and intuitive nature of the writings about thoughtfully adaptive teaching, no one has systematically collected empirical evidence to support such claims (Duffy, Miller, Kear, Parsons, Davis, & Williams, 2008). In response to this need, the current study focused on planning as well as on-the-fly adaptations, included a student…

  7. Adapting physically complete models to vehicle-based EMI array sensor data: data inversion and discrimination studies

    NASA Astrophysics Data System (ADS)

    Shubitidze, Fridon; Miller, Jonathan S.; Schultz, Gregory M.; Marble, Jay A.

    2010-04-01

    This paper reports vehicle based electromagnetic induction (EMI) array sensor data inversion and discrimination results. Recent field studies show that EMI arrays, such as the Minelab Single Transmitter Multiple Receiver (STMR), and the Geophex GEM-5 EMI array, provide a fast and safe way to detect subsurface metallic targets such as landmines, unexploded ordnance (UXO) and buried explosives. The array sensors are flexible and easily adaptable for a variety of ground vehicles and mobile platforms, which makes them very attractive for safe and cost effective detection operations in many applications, including but not limited to explosive ordnance disposal and humanitarian UXO and demining missions. Most state-of-the-art EMI arrays measure the vertical or full vector field, or gradient tensor fields and utilize them for real-time threat detection based on threshold analysis. Real field practice shows that the threshold-level detection has high false alarms. One way to reduce these false alarms is to use EMI numerical techniques that are capable of inverting EMI array data in real time. In this work a physically complete model, known as the normalized volume/surface magnetic sources (NV/SMS) model is adapted to the vehicle-based EMI array, such as STMR and GEM-5, data. The NV/SMS model can be considered as a generalized volume or surface dipole model, which in a special limited case coincides with an infinitesimal dipole model approach. According to the NV/SMS model, an object's response to a sensor's primary field is modeled mathematically by a set of equivalent magnetic dipoles, distributed inside the object (i.e. NVMS) or over a surface surrounding the object (i.e. NSMS). The scattered magnetic field of the NSMS is identical to that produced by a set of interacting magnetic dipoles. The amplitudes of the magnetic dipoles are normalized to the primary magnetic field, relating induced magnetic dipole polarizability and the primary magnetic field. The magnitudes of

  8. A DVH-guided IMRT optimization algorithm for automatic treatment planning and adaptive radiotherapy replanning

    SciTech Connect

    Zarepisheh, Masoud; Li, Nan; Long, Troy; Romeijn, H. Edwin; Tian, Zhen; Jia, Xun; Jiang, Steve B.

    2014-06-15

    Purpose: To develop a novel algorithm that incorporates prior treatment knowledge into intensity modulated radiation therapy optimization to facilitate automatic treatment planning and adaptive radiotherapy (ART) replanning. Methods: The algorithm automatically creates a treatment plan guided by the DVH curves of a reference plan that contains information on the clinician-approved dose-volume trade-offs among different targets/organs and among different portions of a DVH curve for an organ. In ART, the reference plan is the initial plan for the same patient, while for automatic treatment planning the reference plan is selected from a library of clinically approved and delivered plans of previously treated patients with similar medical conditions and geometry. The proposed algorithm employs a voxel-based optimization model and navigates the large voxel-based Pareto surface. The voxel weights are iteratively adjusted to approach a plan that is similar to the reference plan in terms of the DVHs. If the reference plan is feasible but not Pareto optimal, the algorithm generates a Pareto optimal plan with the DVHs better than the reference ones. If the reference plan is too restricting for the new geometry, the algorithm generates a Pareto plan with DVHs close to the reference ones. In both cases, the new plans have similar DVH trade-offs as the reference plans. Results: The algorithm was tested using three patient cases and found to be able to automatically adjust the voxel-weighting factors in order to generate a Pareto plan with similar DVH trade-offs as the reference plan. The algorithm has also been implemented on a GPU for high efficiency. Conclusions: A novel prior-knowledge-based optimization algorithm has been developed that automatically adjust the voxel weights and generate a clinical optimal plan at high efficiency. It is found that the new algorithm can significantly improve the plan quality and planning efficiency in ART replanning and automatic treatment

  9. Planning for an uncertain future - Monitoring, integration, and adaptation

    USGS Publications Warehouse

    Webb, Richard M. T.; Semmens, Darius J.

    2009-01-01

    The 6.7 billion human inhabitants of the earth have the ability to drastically alter ecosystems and the populations of species that have taken eons to evolve. By better understanding how our actions affect the environment, we stand a better chance of designing successful strategies to manage ecosystems sustainably. Toward this end, the Third Interagency Conference on Research in the Watersheds (ICRW) was convened in Estes Park, CO, on September 8-11, 2008. The Conference provided a forum to present adaptive management as a practical tool for learning how to manage complex ecosystems more sustainably. Further complexity introduced by spatially variable and continuously changing environmental drivers favors this management approach because of its emphasis on adaptation in response to changing conditions or ineffective actions. For climate change in particular, an adaptive approach can more effectively accommodate the uncertainty in future climate scenarios. Scenarios compiled by the Intergovernmental Panel on Climate Change are built on distinct economic, energy, and societal models. The scenarios predict potential changes in greenhouse gases, temperature, precipitation, and atmospheric aerosols, which would have direct or indirect impacts on the timing, volume, and quality of runoff, vegetation, snowpack, stream temperature, groundwater, thawing permafrost, and icecaps. Through presentations and field trips, researchers and stakeholders described how their findings and issues fit into the adaptive management 'learning by doing' paradigm of Assess > Design > Implement > Monitor > Evaluate > Adjust > Assess.

  10. A Conceptual Framework for Planning Systemic Human Adaptation to Global Warming.

    PubMed

    Tait, Peter W; Hanna, Elizabeth G

    2015-08-31

    Human activity is having multiple, inter-related effects on ecosystems. Greenhouse gas emissions persisting along current trajectories threaten to significantly alter human society. At 0.85 °C of anthropogenic warming, deleterious human impacts are acutely evident. Additional warming of 0.5 °C-1.0 °C from already emitted CO₂ will further intensify extreme heat and damaging storm events. Failing to sufficiently address this trend will have a heavy human toll directly and indirectly on health. Along with mitigation efforts, societal adaptation to a warmer world is imperative. Adaptation efforts need to be significantly upscaled to prepare society to lessen the public health effects of rising temperatures. Modifying societal behaviour is inherently complex and presents a major policy challenge. We propose a social systems framework for conceptualizing adaptation that maps out three domains within the adaptation policy landscape: acclimatisation, behavioural adaptation and technological adaptation, which operate at societal and personal levels. We propose that overlaying this framework on a systems approach to societal change planning methods will enhance governments' capacity and efficacy in strategic planning for adaptation. This conceptual framework provides a policy oriented planning assessment tool that will help planners match interventions to the behaviours being targeted for change. We provide illustrative examples to demonstrate the framework's application as a planning tool.

  11. A Conceptual Framework for Planning Systemic Human Adaptation to Global Warming

    PubMed Central

    Tait, Peter W.; Hanna, Elizabeth G.

    2015-01-01

    Human activity is having multiple, inter-related effects on ecosystems. Greenhouse gas emissions persisting along current trajectories threaten to significantly alter human society. At 0.85 °C of anthropogenic warming, deleterious human impacts are acutely evident. Additional warming of 0.5 °C–1.0 °C from already emitted CO2 will further intensify extreme heat and damaging storm events. Failing to sufficiently address this trend will have a heavy human toll directly and indirectly on health. Along with mitigation efforts, societal adaptation to a warmer world is imperative. Adaptation efforts need to be significantly upscaled to prepare society to lessen the public health effects of rising temperatures. Modifying societal behaviour is inherently complex and presents a major policy challenge. We propose a social systems framework for conceptualizing adaptation that maps out three domains within the adaptation policy landscape: acclimatisation, behavioural adaptation and technological adaptation, which operate at societal and personal levels. We propose that overlaying this framework on a systems approach to societal change planning methods will enhance governments’ capacity and efficacy in strategic planning for adaptation. This conceptual framework provides a policy oriented planning assessment tool that will help planners match interventions to the behaviours being targeted for change. We provide illustrative examples to demonstrate the framework’s application as a planning tool. PMID:26334285

  12. A Conceptual Framework for Planning Systemic Human Adaptation to Global Warming.

    PubMed

    Tait, Peter W; Hanna, Elizabeth G

    2015-09-01

    Human activity is having multiple, inter-related effects on ecosystems. Greenhouse gas emissions persisting along current trajectories threaten to significantly alter human society. At 0.85 °C of anthropogenic warming, deleterious human impacts are acutely evident. Additional warming of 0.5 °C-1.0 °C from already emitted CO₂ will further intensify extreme heat and damaging storm events. Failing to sufficiently address this trend will have a heavy human toll directly and indirectly on health. Along with mitigation efforts, societal adaptation to a warmer world is imperative. Adaptation efforts need to be significantly upscaled to prepare society to lessen the public health effects of rising temperatures. Modifying societal behaviour is inherently complex and presents a major policy challenge. We propose a social systems framework for conceptualizing adaptation that maps out three domains within the adaptation policy landscape: acclimatisation, behavioural adaptation and technological adaptation, which operate at societal and personal levels. We propose that overlaying this framework on a systems approach to societal change planning methods will enhance governments' capacity and efficacy in strategic planning for adaptation. This conceptual framework provides a policy oriented planning assessment tool that will help planners match interventions to the behaviours being targeted for change. We provide illustrative examples to demonstrate the framework's application as a planning tool. PMID:26334285

  13. Automated and Adaptive Mission Planning for Orbital Express

    NASA Technical Reports Server (NTRS)

    Chouinard, Caroline; Knight, Russell; Jones, Grailing; Tran, Daniel; Koblick, Darin

    2008-01-01

    The Orbital Express space mission was a Defense Advanced Research Projects Agency (DARPA) lead demonstration of on-orbit satellite servicing scenarios, autonomous rendezvous, fluid transfers of hydrazine propellant, and robotic arm transfers of Orbital Replacement Unit (ORU) components. Boeing's Autonomous Space Transport Robotic Operations (ASTRO) vehicle provided the servicing to the Ball Aerospace's Next Generation Serviceable Satellite (NextSat) client. For communication opportunities, operations used the high-bandwidth ground-based Air Force Satellite Control Network (AFSCN) along with the relatively low-bandwidth GEO-Synchronous space-borne Tracking and Data Relay Satellite System (TDRSS) network. Mission operations were conducted out of the RDT&E Support Complex (RSC) at the Kirtland Air Force Base in New Mexico. All mission objectives were met successfully: The first of several autonomous rendezvous was demonstrated on May 5, 2007; autonomous free-flyer capture was demonstrated on June 22, 2007; the fluid and ORU transfers throughout the mission were successful. Planning operations for the mission were conducted by a team of personnel including Flight Directors, who were responsible for verifying the steps and contacts within the procedures, the Rendezvous Planners who would compute the locations and visibilities of the spacecraft, the Scenario Resource Planners (SRPs), who were concerned with assignment of communications windows, monitoring of resources, and sending commands to the ASTRO spacecraft, and the Mission planners who would interface with the real-time operations environment, process planning products and coordinate activities with the SRP. The SRP position was staffed by JPL personnel who used the Automated Scheduling and Planning ENvironment (ASPEN) to model and enforce mission and satellite constraints. The lifecycle of a plan began three weeks outside its execution on-board. During the planning timeframe, many aspects could change the plan

  14. Dosimetric benefit of adaptive re-planning in pancreatic cancer stereotactic body radiotherapy.

    PubMed

    Li, Yongbao; Hoisak, Jeremy D P; Li, Nan; Jiang, Carrie; Tian, Zhen; Gautier, Quentin; Zarepisheh, Masoud; Wu, Zhaoxia; Liu, Yaqiang; Jia, Xun; Hattangadi-Gluth, Jona; Mell, Loren K; Jiang, Steve; Murphy, James D

    2015-01-01

    Stereotactic body radiotherapy (SBRT) shows promise in unresectable pancreatic cancer, though this treatment modality has high rates of normal tissue toxicity. This study explores the dosimetric utility of daily adaptive re-planning with pancreas SBRT. We used a previously developed supercomputing online re-planning environment (SCORE) to re-plan 10 patients with pancreas SBRT. Tumor and normal tissue contours were deformed from treatment planning computed tomographies (CTs) and transferred to daily cone-beam CT (CBCT) scans before re-optimizing each daily treatment plan. We compared the intended radiation dose, the actual radiation dose, and the optimized radiation dose for the pancreas tumor planning target volume (PTV) and the duodenum. Treatment re-optimization improved coverage of the PTV and reduced dose to the duodenum. Within the PTV, the actual hot spot (volume receiving 110% of the prescription dose) decreased from 4.5% to 0.5% after daily adaptive re-planning. Within the duodenum, the volume receiving the prescription dose decreased from 0.9% to 0.3% after re-planning. It is noteworthy that variation in the amount of air within a patient׳s stomach substantially changed dose to the PTV. Adaptive re-planning with pancreas SBRT has the ability to improve dose to the tumor and decrease dose to the nearby duodenum, thereby reducing the risk of toxicity. PMID:26002122

  15. Using Uncertain Climate and Development Information in Health Adaptation Planning.

    PubMed

    Ebi, Kristie L; Hess, Jeremy J; Isaksen, Tania Busch

    2016-03-01

    To aid health adaptation decision-making, there are increasing efforts to provide climate projections at finer temporal and spatial scales. Relying solely on projected climate changes for longer-term decisions makes the implicit assumption that sources of vulnerability other than climate change will remain the same, which is not very probable. Over longer time horizons, this approach likely over estimates the extent to which climate change could alter the magnitude and pattern of health outcomes, introducing systematic bias into health management decisions. To balance this potential bias, decision-makers also need projections of other drivers of health outcomes that are, like climate change, recognized determinants of some disease burdens. Incorporating projections via an iterative process that allows for regular updates based on new knowledge and experience has the potential to improve the utility of fine-scale climate projections in health system adaptation to climate change.

  16. The Adapted Dance Process: Planning, Partnering, and Performing

    ERIC Educational Resources Information Center

    Block, Betty A.; Johnson, Peggy V.

    2011-01-01

    This article contains specific planning, partnering, and performing techniques for fully integrating dancers with special needs into a dance pedagogy program. Each aspect is discussed within the context of the domains of learning. Fundamental partnering strategies are related to each domain as part of the integration process. The authors recommend…

  17. An information adaptive system study report and development plan

    NASA Technical Reports Server (NTRS)

    Ataras, W. S.; Eng, K.; Morone, J. J.; Beaudet, P. R.; Chin, R.

    1980-01-01

    The purpose of the information adaptive system (IAS) study was to determine how some selected Earth resource applications may be processed onboard a spacecraft and to provide a detailed preliminary IAS design for these applications. Detailed investigations of a number of applications were conducted with regard to IAS and three were selected for further analysis. Areas of future research and development include algorithmic specifications, system design specifications, and IAS recommended time lines.

  18. Climate change adaptation strategies for resource management and conservation planning.

    PubMed

    Lawler, Joshua J

    2009-04-01

    Recent rapid changes in the Earth's climate have altered ecological systems around the globe. Global warming has been linked to changes in physiology, phenology, species distributions, interspecific interactions, and disturbance regimes. Projected future climate change will undoubtedly result in even more dramatic shifts in the states of many ecosystems. These shifts will provide one of the largest challenges to natural resource managers and conservation planners. Managing natural resources and ecosystems in the face of uncertain climate requires new approaches. Here, the many adaptation strategies that have been proposed for managing natural systems in a changing climate are reviewed. Most of the recommended approaches are general principles and many are tools that managers are already using. What is new is a turning toward a more agile management perspective. To address climate change, managers will need to act over different spatial and temporal scales. The focus of restoration will need to shift from historic species assemblages to potential future ecosystem services. Active adaptive management based on potential future climate impact scenarios will need to be a part of everyday operations. And triage will likely become a critical option. Although many concepts and tools for addressing climate change have been proposed, key pieces of information are still missing. To successfully manage for climate change, a better understanding will be needed of which species and systems will likely be most affected by climate change, how to preserve and enhance the evolutionary capacity of species, how to implement effective adaptive management in new systems, and perhaps most importantly, in which situations and systems will the general adaptation strategies that have been proposed work and how can they be effectively applied.

  19. Health Aspects of Climate Change in Cities with Mediterranean Climate, and Local Adaptation Plans

    PubMed Central

    Paz, Shlomit; Negev, Maya; Clermont, Alexandra; Green, Manfred S.

    2016-01-01

    Cities with a Mediterranean-type climate (Med-cities) are particularly susceptible to health risks from climate change since they are located in biogeographical hot-spots that experience some of the strongest effects of the changing climate. The study aims to highlight health impacts of climate change in Med-cities, analyze local climate adaptation plans and make adaptation policy recommendations for the Med-city level. We identified five Med-cities with a climate change adaptation plan: Adelaide, Barcelona, Cape Town, Los Angeles and Santiago. Beyond their similar Med-climate features (although Santiago’s are slightly different), the cities have different socio-economic characteristics in various aspects. We analyzed each plan according to how it addresses climate change-related drivers of health impacts among city dwellers. For each driver, we identified the types of policy adaptation tools that address it in the urban climate adaptation plans. The surveyed cities address most of the fundamental climate change-related drivers of risks to human health, including rising temperatures, flooding and drought, but the policy measures to reduce negative impacts vary across cities. We suggest recommendations for Med-cities in various aspects, depending on their local needs and vulnerability challenges: assessment of health risks, extreme events management and long-term adaptation, among others. PMID:27110801

  20. Health Aspects of Climate Change in Cities with Mediterranean Climate, and Local Adaptation Plans.

    PubMed

    Paz, Shlomit; Negev, Maya; Clermont, Alexandra; Green, Manfred S

    2016-04-21

    Cities with a Mediterranean-type climate (Med-cities) are particularly susceptible to health risks from climate change since they are located in biogeographical hot-spots that experience some of the strongest effects of the changing climate. The study aims to highlight health impacts of climate change in Med-cities, analyze local climate adaptation plans and make adaptation policy recommendations for the Med-city level. We identified five Med-cities with a climate change adaptation plan: Adelaide, Barcelona, Cape Town, Los Angeles and Santiago. Beyond their similar Med-climate features (although Santiago's are slightly different), the cities have different socio-economic characteristics in various aspects. We analyzed each plan according to how it addresses climate change-related drivers of health impacts among city dwellers. For each driver, we identified the types of policy adaptation tools that address it in the urban climate adaptation plans. The surveyed cities address most of the fundamental climate change-related drivers of risks to human health, including rising temperatures, flooding and drought, but the policy measures to reduce negative impacts vary across cities. We suggest recommendations for Med-cities in various aspects, depending on their local needs and vulnerability challenges: assessment of health risks, extreme events management and long-term adaptation, among others.

  1. Health Aspects of Climate Change in Cities with Mediterranean Climate, and Local Adaptation Plans.

    PubMed

    Paz, Shlomit; Negev, Maya; Clermont, Alexandra; Green, Manfred S

    2016-04-01

    Cities with a Mediterranean-type climate (Med-cities) are particularly susceptible to health risks from climate change since they are located in biogeographical hot-spots that experience some of the strongest effects of the changing climate. The study aims to highlight health impacts of climate change in Med-cities, analyze local climate adaptation plans and make adaptation policy recommendations for the Med-city level. We identified five Med-cities with a climate change adaptation plan: Adelaide, Barcelona, Cape Town, Los Angeles and Santiago. Beyond their similar Med-climate features (although Santiago's are slightly different), the cities have different socio-economic characteristics in various aspects. We analyzed each plan according to how it addresses climate change-related drivers of health impacts among city dwellers. For each driver, we identified the types of policy adaptation tools that address it in the urban climate adaptation plans. The surveyed cities address most of the fundamental climate change-related drivers of risks to human health, including rising temperatures, flooding and drought, but the policy measures to reduce negative impacts vary across cities. We suggest recommendations for Med-cities in various aspects, depending on their local needs and vulnerability challenges: assessment of health risks, extreme events management and long-term adaptation, among others. PMID:27110801

  2. Physically constrained voxel-based penalty adaptation for ultra-fast IMRT planning.

    PubMed

    Wahl, Niklas; Bangert, Mark; Kamerling, Cornelis P; Ziegenhein, Peter; Bol, Gijsbert H; Raaymakers, Bas W; Oelfke, Uwe

    2016-07-08

    Conventional treatment planning in intensity-modulated radiation therapy (IMRT) is a trial-and-error process that usually involves tedious tweaking of optimization parameters. Here, we present an algorithm that automates part of this process, in particular the adaptation of voxel-based penalties within normal tissue. Thereby, the proposed algorithm explicitly considers a priori known physical limitations of photon irradiation. The efficacy of the developed algorithm is assessed during treatment planning studies comprising 16 prostate and 5 head and neck cases. We study the eradication of hot spots in the normal tissue, effects on target coverage and target conformity, as well as selected dose volume points for organs at risk. The potential of the proposed method to generate class solutions for the two indications is investigated. Run-times of the algorithms are reported. Physically constrained voxel-based penalty adaptation is an adequate means to automatically detect and eradicate hot-spots during IMRT planning while maintaining target coverage and conformity. Negative effects on organs at risk are comparably small and restricted to lower doses. Using physically constrained voxel-based penalty adaptation, it was possible to improve the generation of class solutions for both indications. Considering the reported run-times of less than 20 s, physically constrained voxel-based penalty adaptation has the potential to reduce the clinical workload during planning and automated treatment plan generation in the long run, facilitating adaptive radiation treatments.

  3. A planning quality evaluation tool for prostate adaptive IMRT based on machine learning

    SciTech Connect

    Zhu Xiaofeng; Ge Yaorong; Li Taoran; Thongphiew, Danthai; Yin Fangfang; Wu, Q Jackie

    2011-02-15

    Purpose: To ensure plan quality for adaptive IMRT of the prostate, we developed a quantitative evaluation tool using a machine learning approach. This tool generates dose volume histograms (DVHs) of organs-at-risk (OARs) based on prior plans as a reference, to be compared with the adaptive plan derived from fluence map deformation. Methods: Under the same configuration using seven-field 15 MV photon beams, DVHs of OARs (bladder and rectum) were estimated based on anatomical information of the patient and a model learned from a database of high quality prior plans. In this study, the anatomical information was characterized by the organ volumes and distance-to-target histogram (DTH). The database consists of 198 high quality prostate plans and was validated with 14 cases outside the training pool. Principal component analysis (PCA) was applied to DVHs and DTHs to quantify their salient features. Then, support vector regression (SVR) was implemented to establish the correlation between the features of the DVH and the anatomical information. Results: DVH/DTH curves could be characterized sufficiently just using only two or three truncated principal components, thus, patient anatomical information was quantified with reduced numbers of variables. The evaluation of the model using the test data set demonstrated its accuracy {approx}80% in prediction and effectiveness in improving ART planning quality. Conclusions: An adaptive IMRT plan quality evaluation tool based on machine learning has been developed, which estimates OAR sparing and provides reference in evaluating ART.

  4. Adaptive Planning: Understanding Organizational Workload to Capability/ Capacity through Modeling and Simulation

    NASA Technical Reports Server (NTRS)

    Hase, Chris

    2010-01-01

    In August 2003, the Secretary of Defense (SECDEF) established the Adaptive Planning (AP) initiative [1] with an objective of reducing the time necessary to develop and revise Combatant Commander (COCOM) contingency plans and increase SECDEF plan visibility. In addition to reducing the traditional plan development timeline from twenty-four months to less than twelve months (with a goal of six months)[2], AP increased plan visibility to Department of Defense (DoD) leadership through In-Progress Reviews (IPRs). The IPR process, as well as the increased number of campaign and contingency plans COCOMs had to develop, increased the workload while the number of planners remained fixed. Several efforts from collaborative planning tools to streamlined processes were initiated to compensate for the increased workload enabling COCOMS to better meet shorter planning timelines. This paper examines the Joint Strategic Capabilities Plan (JSCP) directed contingency planning and staffing requirements assigned to a combatant commander staff through the lens of modeling and simulation. The dynamics of developing a COCOM plan are captured with an ExtendSim [3] simulation. The resulting analysis provides a quantifiable means by which to measure a combatant commander staffs workload associated with development and staffing JSCP [4] directed contingency plans with COCOM capability/capacity. Modeling and simulation bring significant opportunities in measuring the sensitivity of key variables in the assessment of workload to capability/capacity analysis. Gaining an understanding of the relationship between plan complexity, number of plans, planning processes, and number of planners with time required for plan development provides valuable information to DoD leadership. Through modeling and simulation AP leadership can gain greater insight in making key decisions on knowing where to best allocate scarce resources in an effort to meet DoD planning objectives.

  5. Quality Assurance/Quality Control Issues for Intraoperative Planning and Adaptive Repeat Planning of Image-Guided Prostate Implants

    SciTech Connect

    Zaider, Marco Cohen, Gilad; Meli, Jerome; Rosenfeld, Anatoly B.

    2008-05-01

    The quality assurance/quality control purpose is this. We design a treatment plan, and we wish to be as certain as reasonably possible that the treatment is delivered as planned. In the case of conventionally planned prostate brachytherapy, implementing to the letter the implantation plan is rarely attainable and therefore can require adaptive replanning (a quality control issue). The reasons for this state of affairs include changes in the prostate shape and volume during implantation and treatment delivery (e.g., edema resolution) and unavoidable inaccuracy in the placement of the seeds in the prostate. As a result, quality-control activities (e.g., the need to monitor-ideally, on the fly-the target and urethral and rectal dosage) must be also addressed.

  6. Spatiotemporal Movement Planning and Rapid Adaptation for Manual Interaction

    PubMed Central

    Huber, Markus; Kupferberg, Aleksandra; Lenz, Claus; Knoll, Alois; Brandt, Thomas; Glasauer, Stefan

    2013-01-01

    Many everyday tasks require the ability of two or more individuals to coordinate their actions with others to increase efficiency. Such an increase in efficiency can often be observed even after only very few trials. Previous work suggests that such behavioral adaptation can be explained within a probabilistic framework that integrates sensory input and prior experience. Even though higher cognitive abilities such as intention recognition have been described as probabilistic estimation depending on an internal model of the other agent, it is not clear whether much simpler daily interaction is consistent with a probabilistic framework. Here, we investigate whether the mechanisms underlying efficient coordination during manual interactions can be understood as probabilistic optimization. For this purpose we studied in several experiments a simple manual handover task concentrating on the action of the receiver. We found that the duration until the receiver reacts to the handover decreases over trials, but strongly depends on the position of the handover. We then replaced the human deliverer by different types of robots to further investigate the influence of the delivering movement on the reaction of the receiver. Durations were found to depend on movement kinematics and the robot’s joint configuration. Modeling the task was based on the assumption that the receiver’s decision to act is based on the accumulated evidence for a specific handover position. The evidence for this handover position is collected from observing the hand movement of the deliverer over time and, if appropriate, by integrating this sensory likelihood with prior expectation that is updated over trials. The close match of model simulations and experimental results shows that the efficiency of handover coordination can be explained by an adaptive probabilistic fusion of a-priori expectation and online estimation. PMID:23724112

  7. Adaptive Radiotherapy Planning on Decreasing Gross Tumor Volumes as Seen on Megavoltage Computed Tomography Images

    SciTech Connect

    Woodford, Curtis; Yartsev, Slav Dar, A. Rashid; Bauman, Glenn; Van Dyk, Jake

    2007-11-15

    Purpose: To evaluate gross tumor volume (GTV) changes for patients with non-small-cell lung cancer by using daily megavoltage (MV) computed tomography (CT) studies acquired before each treatment fraction on helical tomotherapy and to relate the potential benefit of adaptive image-guided radiotherapy to changes in GTV. Methods and Materials: Seventeen patients were prescribed 30 fractions of radiotherapy on helical tomotherapy for non-small-cell lung cancer at London Regional Cancer Program from Dec 2005 to March 2007. The GTV was contoured on the daily MVCT studies of each patient. Adapted plans were created using merged MVCT-kilovoltage CT image sets to investigate the advantages of replanning for patients with differing GTV regression characteristics. Results: Average GTV change observed over 30 fractions was -38%, ranging from -12 to -87%. No significant correlation was observed between GTV change and patient's physical or tumor features. Patterns of GTV changes in the 17 patients could be divided broadly into three groups with distinctive potential for benefit from adaptive planning. Conclusions: Changes in GTV are difficult to predict quantitatively based on patient or tumor characteristics. If changes occur, there are points in time during the treatment course when it may be appropriate to adapt the plan to improve sparing of normal tissues. If GTV decreases by greater than 30% at any point in the first 20 fractions of treatment, adaptive planning is appropriate to further improve the therapeutic ratio.

  8. Real-time inverse high-dose-rate brachytherapy planning with catheter optimization by compressed sensing-inspired optimization strategies

    NASA Astrophysics Data System (ADS)

    Guthier, C. V.; Aschenbrenner, K. P.; Müller, R.; Polster, L.; Cormack, R. A.; Hesser, J. W.

    2016-08-01

    This paper demonstrates that optimization strategies derived from the field of compressed sensing (CS) improve computational performance in inverse treatment planning (ITP) for high-dose-rate (HDR) brachytherapy. Following an approach applied to low-dose-rate brachytherapy, we developed a reformulation of the ITP problem with the same mathematical structure as standard CS problems. Two greedy methods, derived from hard thresholding and subspace pursuit are presented and their performance is compared to state-of-the-art ITP solvers. Applied to clinical prostate brachytherapy plans speed-up by a factor of 56-350 compared to state-of-the-art methods. Based on a Wilcoxon signed rank-test the novel method statistically significantly decreases the final objective function value (p  <  0.01). The optimization times were below one second and thus planing can be considered as real-time capable. The novel CS inspired strategy enables real-time ITP for HDR brachytherapy including catheter optimization. The generated plans are either clinically equivalent or show a better performance with respect to dosimetric measures.

  9. Real-time inverse high-dose-rate brachytherapy planning with catheter optimization by compressed sensing-inspired optimization strategies

    NASA Astrophysics Data System (ADS)

    Guthier, C. V.; Aschenbrenner, K. P.; Müller, R.; Polster, L.; Cormack, R. A.; Hesser, J. W.

    2016-08-01

    This paper demonstrates that optimization strategies derived from the field of compressed sensing (CS) improve computational performance in inverse treatment planning (ITP) for high-dose-rate (HDR) brachytherapy. Following an approach applied to low-dose-rate brachytherapy, we developed a reformulation of the ITP problem with the same mathematical structure as standard CS problems. Two greedy methods, derived from hard thresholding and subspace pursuit are presented and their performance is compared to state-of-the-art ITP solvers. Applied to clinical prostate brachytherapy plans speed-up by a factor of 56–350 compared to state-of-the-art methods. Based on a Wilcoxon signed rank-test the novel method statistically significantly decreases the final objective function value (p  <  0.01). The optimization times were below one second and thus planing can be considered as real-time capable. The novel CS inspired strategy enables real-time ITP for HDR brachytherapy including catheter optimization. The generated plans are either clinically equivalent or show a better performance with respect to dosimetric measures.

  10. Real-time inverse high-dose-rate brachytherapy planning with catheter optimization by compressed sensing-inspired optimization strategies.

    PubMed

    Guthier, C V; Aschenbrenner, K P; Müller, R; Polster, L; Cormack, R A; Hesser, J W

    2016-08-21

    This paper demonstrates that optimization strategies derived from the field of compressed sensing (CS) improve computational performance in inverse treatment planning (ITP) for high-dose-rate (HDR) brachytherapy. Following an approach applied to low-dose-rate brachytherapy, we developed a reformulation of the ITP problem with the same mathematical structure as standard CS problems. Two greedy methods, derived from hard thresholding and subspace pursuit are presented and their performance is compared to state-of-the-art ITP solvers. Applied to clinical prostate brachytherapy plans speed-up by a factor of 56-350 compared to state-of-the-art methods. Based on a Wilcoxon signed rank-test the novel method statistically significantly decreases the final objective function value (p  <  0.01). The optimization times were below one second and thus planing can be considered as real-time capable. The novel CS inspired strategy enables real-time ITP for HDR brachytherapy including catheter optimization. The generated plans are either clinically equivalent or show a better performance with respect to dosimetric measures. PMID:27435044

  11. SU-E-J-80: A Comparative Analysis of MIM and Pinnacle Software for Adaptive Planning

    SciTech Connect

    Stanford, J; Duggar, W; Morris, B; Yang, C

    2015-06-15

    Purpose: IMRT treatment is often administered with image guidance and small PTV margins. Change in body habitus such as weight loss and tumor response during the course of a treatment could be significant, thus warranting re-simulation and re-planning. Adaptive planning is challenging and places significant burden on the staff, as such some commercial vendors are now offering adaptive planning software to stream line the process of re-planning and dose accumulation between different CT data set. The purpose of this abstract is to compare the adaptive planning tools between Pinnacle version 9.8 and MIM 6.4 software. Methods: Head and Neck cases of previously treated patients that experienced anatomical changes during the course of their treatment were chosen for evaluation. The new CT data set from the re-simulation was imported to Pinnacle and MIM software. The dynamic planning tool in pinnacle was used to calculate the old plan with fixed MU setting on the new CT data. In MIM, the old CT was registered to the new data set, followed by a dose transformation to the new CT. The dose distribution to the PTV and critical structures from each software were analyzed and compared. Results: 9% difference was observed between the Global maximum doses reported by both software. Mean doses to organs at risk and PTV’s were within 6 % however pinnacle showed greater difference in PTV coverage change. Conclusion: MIM software adaptive planning corrects for geometrical changes without consideration for the effect of radiological path length on dose distribution; however Pinnacle corrects for both geometric and radiological effect on the dose distribution. Pinnacle gives a better estimate of the dosimetric impact due to anatomical changes.

  12. On-line re-optimization of prostate IMRT plans for adaptive radiation therapy

    NASA Astrophysics Data System (ADS)

    Wu, Q. Jackie; Thongphiew, Danthai; Wang, Zhiheng; Mathayomchan, Boonyanit; Chankong, Vira; Yoo, Sua; Lee, W. Robert; Yin, Fang-Fang

    2008-02-01

    For intermediate and high risk prostate cancer, both the prostate gland and seminal vesicles are included in the clinical target volume. Internal motion patterns of these two organs vary, presenting a challenge for adaptive treatment. Adaptive techniques such as isocenter repositioning and soft tissue alignment are effective when tumor volumes only exhibit translational shift, while direct re-optimization of the intensity-modulated radiation therapy (IMRT) plan maybe more desirable when extreme deformation or differential positioning changes of the organs occur. Currently, direct re-optimization of the IMRT plan using beamlet (or fluence map) has not been reported. In this study, we report a novel on-line re-optimization technique that can accomplish plan adjustment on-line. Deformable image registration is used to provide position variation information on each voxel along the three dimensions. The original planned dose distribution is used as the 'goal' dose distribution for adaptation and to ensure planning quality. Fluence maps are re-optimized via linear programming, and a plan solution can be achieved within 2 min. The feasibility of this technique is demonstrated with a clinical case with large deformation. Such on-line ART process can be highly valuable with hypo-fractionated prostate IMRT treatment. Abstract and preliminary data presented at 49th AAPM Annual Meeting, Minneapolis, MN, USA, July 2007.

  13. On-line re-optimization of prostate IMRT plans for adaptive radiation therapy.

    PubMed

    Wu, Q Jackie; Thongphiew, Danthai; Wang, Zhiheng; Mathayomchan, Boonyanit; Chankong, Vira; Yoo, Sua; Lee, W Robert; Yin, Fang-Fang

    2008-02-01

    For intermediate and high risk prostate cancer, both the prostate gland and seminal vesicles are included in the clinical target volume. Internal motion patterns of these two organs vary, presenting a challenge for adaptive treatment. Adaptive techniques such as isocenter repositioning and soft tissue alignment are effective when tumor volumes only exhibit translational shift, while direct re-optimization of the intensity-modulated radiation therapy (IMRT) plan maybe more desirable when extreme deformation or differential positioning changes of the organs occur. Currently, direct re-optimization of the IMRT plan using beamlet (or fluence map) has not been reported. In this study, we report a novel on-line re-optimization technique that can accomplish plan adjustment on-line. Deformable image registration is used to provide position variation information on each voxel along the three dimensions. The original planned dose distribution is used as the 'goal' dose distribution for adaptation and to ensure planning quality. Fluence maps are re-optimized via linear programming, and a plan solution can be achieved within 2 min. The feasibility of this technique is demonstrated with a clinical case with large deformation. Such on-line ART process can be highly valuable with hypo-fractionated prostate IMRT treatment. PMID:18199909

  14. A morphological adaptation approach to path planning inspired by slime mould

    NASA Astrophysics Data System (ADS)

    Jones, Jeff

    2015-04-01

    Path planning is a classic problem in computer science and robotics which has recently been implemented in unconventional computing substrates such as chemical reaction-diffusion computers. These novel computing schemes utilise the parallel spatial propagation of information and often use a two-stage method involving diffusive propagation to discover all paths and a second stage to highlight or visualise the path between two particular points in the arena. The true slime mould Physarum polycephalum is known to construct efficient transport networks between nutrients in its environment. These networks are continuously remodelled as the organism adapts its body plan to changing spatial stimuli. It can be guided towards attractant stimuli (nutrients, warm regions) and it avoids locations containing hazardous stimuli (light irradiation, repellents, or regions occupied by predatory threats). Using a particle model of slime mould we demonstrate scoping experiments which explore how path planning may be performed by morphological adaptation. We initially demonstrate simple path planning by a shrinking blob of virtual plasmodium between two attractant sources within a polygonal arena. We examine the case where multiple paths are required and the subsequent selection of a single path from multiple options. Collision-free paths are implemented via repulsion from the borders of the arena. Finally, obstacle avoidance is implemented by repulsion from obstacles as they are uncovered by the shrinking blob. These examples show proof-of-concept results of path planning by morphological adaptation which complement existing research on path planning in novel computing substrates.

  15. Adaptive/non-adaptive proton radiation planning and outcome in a phase II trial for locally advanced non-small cell lung cancer

    PubMed Central

    Koay, Eugene J.; Lege, David; Mohan, Radhe; Komaki, Ritsuko; Cox, James D.; Chang, Joe Y.

    2012-01-01

    Purpose To analyze dosimetric variables and outcomes after adaptive replanning of radiotherapy during concurrent high-dose protons and chemotherapy for locally advanced non-small cell lung cancer (NSCLC). Methods and Materials Nine of 44 patients with stage III NSCLC in a prospective phase II trial of concurrent paclitaxel/carboplatin with proton radiation [74 Gy(RBE) in 37 fractions] had modifications to their original treatment plans after re-evaluation revealed changes that would compromise coverage of the target volume or violate dose constraints; plans for the other 35 patients were not changed. We compared patients with adaptive plans with those with nonadaptive plans in terms of dosimetry and outcomes. Results At a median follow-up of 21.2 months (median overall survival, 29.6 months), no differences were found in local, regional, or distant failure or overall survival between groups. Adaptive planning was used more often for large tumors that shrank to a greater extent (median, 107.1 cm3 adaptive and 86.4 cm3 non-adaptive; median changes in volume, 25.3% adaptive and 1.2% non-adaptive; p<0.01). The median number of fractions delivered using adaptive planning was 13 (range, 4–22). Adaptive planning generally improved sparing of the esophagus (median absolute decrease in V70, 1.8%; range, 0–22.9%) and spinal cord (median absolute change in maximum dose, 3.7 Gy; range, 0–13.8 Gy). Without adaptive replanning, target coverage would have been compromised in 2 cases (57% and 82% coverage without adaptation vs. 100% for both with adaptation); neither patient experienced local failure. Radiation-related grade 3 toxicity rates were similar between groups. Conclusions Adaptive planning can reduce normal tissue doses and prevent target misses, particularly for patients with large tumors that shrink substantially during therapy. Adaptive plans seem to have acceptable toxicity and achieve similar local, regional, and distant control and overall survival, even in

  16. Uncertainties encountered in implementation of adaptive planning with in vivo dosimeters.

    PubMed

    Studenski, M T; Gardner, S J; Den, R B

    2015-01-01

    Under a previously approved institutional review board protocol for prostate cancer patients, implanted metal-oxide semiconductor field-effect transistor dosimeters (dose verification system, Sicel Technologies) were used for measurement of the in vivo delivered daily dose. This dosimetric information provided the ability to adapt the plan if the measured doses did not match the dose expected from the planning system. Due to the inherent uncertainty in the dosimeters, the decision to adapt the treatment plan was made only if readings differed by more than 7 % for three consecutive days. To validate this method, we acquired daily cone beam computed tomography images for five patients, and the dose delivered to the dosimeters was calculated by use of (1) an automated procedure (MIM Maestro, MIM Software) and (2) the treatment planning system (XIO, Elekta). 72 % of the doses calculated automatically fell within 1 % of the doses calculated in the planning system, and 99 % agreed within 2 %. When compared to the calculated dose, 53 % of the in vivo measurements fell within 3 % of the calculated dose, 80 % fell within 5 %, and 9.8 % were greater than 7 %, but never on three consecutive days. The measured doses agreed reasonably well with the calculated doses, supporting the decision to adapt the plan only if there were discrepancies of more than 7 % over three consecutive days. Even with the inherent uncertainty in the dosimeters, this adaptive planning method can detect delivery inaccuracies that would not otherwise be caught with the use of only daily image guidance or other dose calculation surrogates.

  17. SU-E-J-135: Feasibility of Using Quantitative Cone Beam CT for Proton Adaptive Planning

    SciTech Connect

    Jingqian, W; Wang, Q; Zhang, X; Wen, Z; Zhu, X; Frank, S; Li, H; Tsui, T; Zhu, L; Wei, J

    2015-06-15

    Purpose: To investigate the feasibility of using scatter corrected cone beam CT (CBCT) for proton adaptive planning. Methods: Phantom study was used to evaluate the CT number difference between the planning CT (pCT), quantitative CBCT (qCBCT) with scatter correction and calibrated Hounsfield units using adaptive scatter kernel superposition (ASKS) technique, and raw CBCT (rCBCT). After confirming the CT number accuracy, prostate patients, each with a pCT and several sets of weekly CBCT, were investigated for this study. Spot scanning proton treatment plans were independently generated on pCT, qCBCT and rCBCT. The treatment plans were then recalculated on all images. Dose-volume-histogram (DVH) parameters and gamma analysis were used to compare between dose distributions. Results: Phantom study suggested that Hounsfield unit accuracy for different materials are within 20 HU for qCBCT and over 250 HU for rCBCT. For prostate patients, proton dose could be calculated accurately on qCBCT but not on rCBCT. When the original plan was recalculated on qCBCT, tumor coverage was maintained when anatomy was consistent with pCT. However, large dose variance was observed when patient anatomy change. Adaptive plan using qCBCT was able to recover tumor coverage and reduce dose to normal tissue. Conclusion: It is feasible to use qu antitative CBCT (qCBCT) with scatter correction and calibrated Hounsfield units for proton dose calculation and adaptive planning in proton therapy. Partly supported by Varian Medical Systems.

  18. Uncertainties encountered in implementation of adaptive planning with in vivo dosimeters.

    PubMed

    Studenski, M T; Gardner, S J; Den, R B

    2015-01-01

    Under a previously approved institutional review board protocol for prostate cancer patients, implanted metal-oxide semiconductor field-effect transistor dosimeters (dose verification system, Sicel Technologies) were used for measurement of the in vivo delivered daily dose. This dosimetric information provided the ability to adapt the plan if the measured doses did not match the dose expected from the planning system. Due to the inherent uncertainty in the dosimeters, the decision to adapt the treatment plan was made only if readings differed by more than 7 % for three consecutive days. To validate this method, we acquired daily cone beam computed tomography images for five patients, and the dose delivered to the dosimeters was calculated by use of (1) an automated procedure (MIM Maestro, MIM Software) and (2) the treatment planning system (XIO, Elekta). 72 % of the doses calculated automatically fell within 1 % of the doses calculated in the planning system, and 99 % agreed within 2 %. When compared to the calculated dose, 53 % of the in vivo measurements fell within 3 % of the calculated dose, 80 % fell within 5 %, and 9.8 % were greater than 7 %, but never on three consecutive days. The measured doses agreed reasonably well with the calculated doses, supporting the decision to adapt the plan only if there were discrepancies of more than 7 % over three consecutive days. Even with the inherent uncertainty in the dosimeters, this adaptive planning method can detect delivery inaccuracies that would not otherwise be caught with the use of only daily image guidance or other dose calculation surrogates. PMID:25236778

  19. Adaptive fault discretization for the inversion of geodetic data with an application to the 2011 Tohoku-oki earthquake

    NASA Astrophysics Data System (ADS)

    Aoki, Y.

    2013-12-01

    Recent development of geodetic observations allows us to image slip distribution on buried faults during interseismic, coseismic, and postseismic peiords. The capability of imaging fault slips at depth from geodetic data is, however, limited because geodetic observations are almost always done at Earth's surface. In addition, the absence of or limited offshore geodetic measurements make detailed imaging of the slip on a shallow offshore fault difficult. In geodetic inversions, spatial distribution of fault slips is often obtained by applying smoothing constraints. However, the optimum choice of the smoothing parameter is not straightforward. Although several studies have proposed methods to choose the optimum smoothing parameter, they do not always give a definitive optimum parameter. Also a single smoothing parameter cannot take the heterogeneous spatial resolution on the fault plane into account. Here I propose a method to adaptively discretize a fault plane of arbitrary shape according to the spatial resolution to ope with the heterogeneous spatial resolution on the fault plane. The method applies Singular Value Decomposition of the data kernel, a matrix that relates the observation to the fault slip, to truncate higher modes, and continues to discretize the fault plane by Voronoi diagrams as long as diagonal elements of the model resolution matrix are above a specified threshold. The only parameter that needs to be set in this method is the truncation threshold of eigenmodes that is determined roughly by the signal-to-noise ratio of the observation. Note that the real dataset is not necessary to evaluate the spatial resolution of the fault slip but only the truncation threshold of eigenmodes needs to be preset. I applied the method to the coseismic displacement field associated with the 2011 Tohoku earthquake. I evaluated the spatial resolution of the inverted fault slip with and without offshore GPS measurements. The spatial resolution at a depth of 50 km is

  20. Adapted Physical Education in Self-Contained Settings: Planning for Successful Instruction

    ERIC Educational Resources Information Center

    Wilson, Wesley J.; Beamer, Jennifer; Block, Martin E.

    2016-01-01

    Nearly 30% of U.S. schools have students with severe disabilities who participate in a self-contained adapted physical education (SAPE) setting, separate from their typically developing classmates. It is imperative that physical education teachers become familiar with pedagogical strategies for planning and teaching SAPE. The purpose of this…

  1. Linking Climate Risk, Policy Networks and Adaptation Planning in Public Lands

    NASA Astrophysics Data System (ADS)

    Lubell, M.; Schwartz, M.; Peters, C.

    2014-12-01

    Federal public land management agencies in the United States have engaged a variety of planning efforts to address climate adaptation. A major goal of these efforts is to build policy networks that enable land managers to access information and expertise needed for responding to local climate risks. This paper investigates whether the perceived and modeled climate risk faced by different land managers is leading to larger networks or more participating in climate adaptation. In theory, the benefits of climate planning networks are larger when land managers are facing more potential changes. The basic hypothesis is tested with a survey of public land managers from hundreds of local and regional public lands management units in the Southwestern United States, as well as other stakeholders involved with climate adaptation planning. All survey respondents report their perceptions of climate risk along a variety of dimensions, as well as their participation in climate adaptation planning and information sharing networks. For a subset of respondents, we have spatially explicity GIS data about their location, which will be linked with downscaled climate model data. With the focus on climate change, the analysis is a subset of the overall idea of linking social and ecological systems.

  2. Evaluations of an adaptive planning technique incorporating dose feedback in image-guided radiotherapy of prostate cancer

    SciTech Connect

    Liu Han; Wu Qiuwen

    2011-12-15

    Purpose: Online image guidance (IG) has been used to effectively correct the setup error and inter-fraction rigid organ motion for prostate cancer. However, planning margins are still necessary to account for uncertainties such as deformation and intra-fraction motion. The purpose of this study is to investigate the effectiveness of an adaptive planning technique incorporating offline dose feedback to manage inter-fraction motion and residuals from online correction. Methods: Repeated helical CT scans from 28 patients were included in the study. The contours of prostate and organs-at-risk (OARs) were delineated on each CT, and online IG was simulated by matching center-of-mass of prostate between treatment CTs and planning CT. A seven beam intensity modulated radiation therapy (IMRT) plan was designed for each patient on planning CT for a total of 15 fractions. Dose distribution at each fraction was evaluated based on actual contours of the target and OARs from that fraction. Cumulative dose up to each fraction was calculated by tracking each voxel based on a deformable registration algorithm. The cumulative dose was compared with the dose from initial plan. If the deviation exceeded the pre-defined threshold, such as 2% of the D{sub 99} to the prostate, an adaptive planning technique called dose compensation was invoked, in which the cumulative dose distribution was fed back to the treatment planning system and the dose deficit was made up through boost radiation in future treatment fractions. The dose compensation was achieved by IMRT inverse planning. Two weekly compensation delivery strategies were simulated: one intended to deliver the boost dose in all future fractions (schedule A) and the other in the following week only (schedule B). The D{sub 99} to prostate and generalized equivalent uniform dose (gEUD) to rectal wall and bladder were computed and compared with those without the dose compensation. Results: If only 2% underdose is allowed at the end of the

  3. SU-E-T-567: A Three-Field Mono-Isocentric Inverse Treatment Planning Method for the Patients with Larger Breasts

    SciTech Connect

    Zhang, T; Marina, O; Chen, P; Teahan, M; Liu, Q; Benedetti, L

    2014-06-01

    Purpose: The purpose of this study is to develop a three-field monoisocentric inverse breast treatment planning technique without the use of half-beam block. Methods: Conventional three-field breast treatment with supraclavicular half-beam blocked requires two isocenters when the breast is too large to be contained within half-beam. The inferior border of the supraclavicular field and superior borders of the breast fields are matched on patient's skin with the light field. This method causes a large dose variation in the matching region due to daily setup uncertainties and requires a longer treatment setup time. We developed a three-field mono-isocentric planning method for the treatment of larger breasts. The three fields share the same isocenter located in the breast. Beam matching is achieved by rotating collimator, couch and gantry. Furthermore, we employed a mixed open-IMRT inverse optimization method to improve dose uniformity and coverage. Results: Perfect geometric beam matching was achieved by rotating couch, collimator and gantry together. Treatment setup time was significantly reduced without light-field matching during treatment deliveries. Inverse mixed open-IMRT optimization method achieved better dose uniformity and PTV coverage while keeping sufficient air flash to compensate setup and breast shape changes in daily treatments. Conclusion: By eliminating light field matching, the three-field mono-isocentric treatment method can significantly reduce setup time and uncertainty for large breast patients. Plan quality is further improved by inverse IMRT planning.

  4. Approaches to evaluating climate change impacts on species: a guide to initiating the adaptation planning process.

    PubMed

    Rowland, Erika L; Davison, Jennifer E; Graumlich, Lisa J

    2011-03-01

    Assessing the impact of climate change on species and associated management objectives is a critical initial step for engaging in the adaptation planning process. Multiple approaches are available. While all possess limitations to their application associated with the uncertainties inherent in the data and models that inform their results, conducting and incorporating impact assessments into the adaptation planning process at least provides some basis for making resource management decisions that are becoming inevitable in the face of rapidly changing climate. Here we provide a non-exhaustive review of long-standing (e.g., species distribution models) and newly developed (e.g., vulnerability indices) methods used to anticipate the response to climate change of individual species as a guide for managers grappling with how to begin the climate change adaptation process. We address the limitations (e.g., uncertainties in climate change projections) associated with these methods, and other considerations for matching appropriate assessment approaches with the management questions and goals. Thorough consideration of the objectives, scope, scale, time frame and available resources for a climate impact assessment allows for informed method selection. With many data sets and tools available on-line, the capacity to undertake and/or benefit from existing species impact assessments is accessible to those engaged in resource management. With some understanding of potential impacts, even if limited, adaptation planning begins to move toward the development of management strategies and targeted actions that may help to sustain functioning ecosystems and their associated services into the future.

  5. A need for planned adaptation to climate change in the wine industry

    NASA Astrophysics Data System (ADS)

    Metzger, Marc J.; Rounsevell, Mark D. A.

    2011-09-01

    The diversity of wine production depends on subtle differences in microclimate and is therefore especially sensitive to climate change. A warmer climate will impact directly on wine-grapes through over-ripening, drying out, rising acidity levels, and greater vulnerability to pests and disease, resulting in changes in wine quality (e.g. complexity, balance and structure) or potentially the style of wine that can be produced. The growing scientific evidence for significant climate change in the coming decades means that adaptation will be of critical importance to the multi-billion dollar global wine-industry in general, and to quality wine producers in particular (White et al 2006, 2009; Hertsgaard 2011). Adaptation is understood as an adjustment in natural or human systems in response to actual or expected environmental change, which moderates harm or exploits beneficial opportunities (IPCC 2007). Autonomous adaptation has been an integral part of the 20th century wine industry. Technological advances, changes in consumer demand, and global competition have meant that growers and producers have had to adapt to stay in business. The gradual temperature rise in the 20th Century (0.7 °C globally) has been accommodated successfully by gradual changes in vine management, technological measures, production control, and marketing (White et al 2009), although this has in many cases resulted in the production of bolder, more alcoholic wines (Hertsgaard 2011). In spite of this success, the wine industry is surprisingly conservative when it comes to considering longer term planned adaptation for substantial climate change impacts. A few producers are expanding to new locations at higher altitudes or cooler climates (e.g. Torres is developing new vineyards high in the Pyrenees, and Mouton Rothschild is setting up new vineyards in South America), and the legal and cultural restrictions of Appelation d'Origine Cȏntrollée (AOC) systems are being discussed (White et al 2009

  6. Can Perceptions of Environmental and Climate Change in Island Communities Assist in Adaptation Planning Locally?

    PubMed

    Aswani, Shankar; Vaccaro, Ismael; Abernethy, Kirsten; Albert, Simon; de Pablo, Javier Fernández-López

    2015-12-01

    Local perceptions of environmental and climate change, as well as associated adaptations made by local populations, are fundamental for designing comprehensive and inclusive mitigation and adaptation plans both locally and nationally. In this paper, we analyze people's perceptions of environmental and climate-related transformations in communities across the Western Solomon Islands through ethnographic and geospatial methods. Specifically, we documented people's observed changes over the past decades across various environmental domains, and for each change, we asked respondents to identify the causes, timing, and people's adaptive responses. We also incorporated this information into a geographical information system database to produce broad-scale base maps of local perceptions of environmental change. Results suggest that people detected changes that tended to be acute (e.g., water clarity, logging intensity, and agricultural diseases). We inferred from these results that most local observations of and adaptations to change were related to parts of environment/ecosystem that are most directly or indirectly related to harvesting strategies. On the other hand, people were less aware of slower insidious/chronic changes identified by scientific studies. For the Solomon Islands and similar contexts in the insular tropics, a broader anticipatory adaptation planning strategy to climate change should include a mix of local scientific studies and local observations of ongoing ecological changes.

  7. A new methodology for inter- and intrafraction plan adaptation for the MR-linac.

    PubMed

    Kontaxis, C; Bol, G H; Lagendijk, J J W; Raaymakers, B W

    2015-10-01

    The new era of hybrid MRI and linear accelerator machines, including the MR-linac currently being installed in the University Medical Center Utrecht (Utrecht, The Netherlands), will be able to provide the actual anatomy and real-time anatomy changes of the patient's target(s) and organ(s) at risk (OARs) during radiation delivery. In order to be able to take advantage of this input, a new generation of treatment planning systems is needed, that will allow plan adaptation to the latest anatomy state in an online regime. In this paper, we present a treatment planning algorithm for intensity-modulated radiotherapy (IMRT), which is able to compensate for patient anatomy changes. The system consists of an iterative sequencing loop open to anatomy updates and an inter- and intrafraction adaptation scheme that enables convergence to the ideal dose distribution without the need of a final segment weight optimization (SWO). The ability of the system to take into account organ motion and adapt the plan to the latest anatomy state is illustrated using artificial baseline shifts created for three different kidney cases. Firstly, for two kidney cases of different target volumes, we show that the system can account for intrafraction motion, delivering the intended dose to the target with minimal dose deposition to the surroundings compared to conventional plans. Secondly, for a third kidney case we show that our algorithm combined with the interfraction scheme can be used to deliver the prescribed dose while adapting to the changing anatomy during multi-fraction treatments without performing a final SWO. PMID:26371425

  8. A new methodology for inter- and intrafraction plan adaptation for the MR-linac

    NASA Astrophysics Data System (ADS)

    Kontaxis, C.; Bol, G. H.; Lagendijk, J. J. W.; Raaymakers, B. W.

    2015-10-01

    The new era of hybrid MRI and linear accelerator machines, including the MR-linac currently being installed in the University Medical Center Utrecht (Utrecht, The Netherlands), will be able to provide the actual anatomy and real-time anatomy changes of the patient’s target(s) and organ(s) at risk (OARs) during radiation delivery. In order to be able to take advantage of this input, a new generation of treatment planning systems is needed, that will allow plan adaptation to the latest anatomy state in an online regime. In this paper, we present a treatment planning algorithm for intensity-modulated radiotherapy (IMRT), which is able to compensate for patient anatomy changes. The system consists of an iterative sequencing loop open to anatomy updates and an inter- and intrafraction adaptation scheme that enables convergence to the ideal dose distribution without the need of a final segment weight optimization (SWO). The ability of the system to take into account organ motion and adapt the plan to the latest anatomy state is illustrated using artificial baseline shifts created for three different kidney cases. Firstly, for two kidney cases of different target volumes, we show that the system can account for intrafraction motion, delivering the intended dose to the target with minimal dose deposition to the surroundings compared to conventional plans. Secondly, for a third kidney case we show that our algorithm combined with the interfraction scheme can be used to deliver the prescribed dose while adapting to the changing anatomy during multi-fraction treatments without performing a final SWO.

  9. Two-dimensional inverse planning and delivery with a preclinical image guided microirradiator

    SciTech Connect

    Stewart, James M. P.; Lindsay, Patricia E.; Jaffray, David A.

    2013-10-15

    profiles taken through the sock distribution of 3.9%. Mean absolute delivery error across the 0–1 Gy linear dose gradient over 7.5 mm was 0.01 Gy.Conclusions: The work presented here demonstrates the potential for complex dose distributions to be planned and automatically delivered with millimeter scale heterogeneity at submillimeter accuracy. This capability establishes the technical foundation for preclinical validation of biologically guided radiotherapy investigations and development of unique radiobiological experiments.

  10. Quality assurance for online adapted treatment plans: Benchmarking and delivery monitoring simulation

    SciTech Connect

    Li, Taoran Wu, Qiuwen; Yang, Yun; Rodrigues, Anna; Yin, Fang-Fang; Jackie Wu, Q.

    2015-01-15

    Purpose: An important challenge facing online adaptive radiation therapy is the development of feasible and efficient quality assurance (QA). This project aimed to validate the deliverability of online adapted plans and develop a proof-of-concept online delivery monitoring system for online adaptive radiation therapy QA. Methods: The first part of this project benchmarked automatically online adapted prostate treatment plans using traditional portal dosimetry IMRT QA. The portal dosimetry QA results of online adapted plans were compared to original (unadapted) plans as well as randomly selected prostate IMRT plans from our clinic. In the second part, an online delivery monitoring system was designed and validated via a simulated treatment with intentional multileaf collimator (MLC) errors. This system was based on inputs from the dynamic machine information (DMI), which continuously reports actual MLC positions and machine monitor units (MUs) at intervals of 50 ms or less during delivery. Based on the DMI, the system performed two levels of monitoring/verification during the delivery: (1) dynamic monitoring of cumulative fluence errors resulting from leaf position deviations and visualization using fluence error maps (FEMs); and (2) verification of MLC positions against the treatment plan for potential errors in MLC motion and data transfer at each control point. Validation of the online delivery monitoring system was performed by introducing intentional systematic MLC errors (ranging from 0.5 to 2 mm) to the DMI files for both leaf banks. These DMI files were analyzed by the proposed system to evaluate the system’s performance in quantifying errors and revealing the source of errors, as well as to understand patterns in the FEMs. In addition, FEMs from 210 actual prostate IMRT beams were analyzed using the proposed system to further validate its ability to catch and identify errors, as well as establish error magnitude baselines for prostate IMRT delivery

  11. A flexible automatically adaptive surface nuclear magnetic resonance modelling and inversion framework incorporating complex data and static dephasing dynamics

    NASA Astrophysics Data System (ADS)

    Irons, Trevor P.

    Surface nuclear magnetic resonance (sNMR) is the only geophysical technique that can directly and non-invasively detect the presence of subsurface liquid water. The method has established itself as valuable tool for hydrologists and groundwater managers owing to the fact that both porosity and hydraulic conductivity estimates can be made using this technique. Although sNMR has enormous potential, there are many challenges with the technique which hinder it's more widespread adoption. For these reasons sNMR has primarily been used as a 1D groundwater sounding tool, although there exist myriad other applications for a method directly sensitive to liquid water. Simultaneously inverting the entire complex dataset as well as the employment of arrays of separated transmitter and receiver coils and integration with other geophysical methods can help to overcome these limitations. This requires modelling algorithms that can accommodate a widely varying set of survey configurations and scenarios. I present the innovative use of sNMR applied to two geotechnical problems: volcanic landslide hazard characterization on Mt. Baker, Washington and the monitoring of internal erosion in earthen embankments. These applications necessitated the development of a general modelling framework capable of handling arbitrary positioned transmitter and receiver coils as well as 3D water distribution. The advantages of comprehensive (whole dataset) inversion of the entire sNMR record have been established for time-domain inversions. However, these inversions are memory intensive and struggle to fit the phase portion of the dataset-necessitating the regretful dismissal of this valuable information. I instead consider the sNMR inversion problem in the frequency-domain for the first time. There are several benefits: effectively lossless compression, and the ability to easily incorporate and solve for static dephasing dynamics caused by magnetic field inhomogeneities. This has allowed for the

  12. Integrating human responses to climate change into conservation vulnerability assessments and adaptation planning.

    PubMed

    Maxwell, Sean L; Venter, Oscar; Jones, Kendall R; Watson, James E M

    2015-10-01

    The impact of climate change on biodiversity is now evident, with the direct impacts of changing temperature and rainfall patterns and increases in the magnitude and frequency of extreme events on species distribution, populations, and overall ecosystem function being increasingly publicized. Changes in the climate system are also affecting human communities, and a range of human responses across terrestrial and marine realms have been witnessed, including altered agricultural activities, shifting fishing efforts, and human migration. Failing to account for the human responses to climate change is likely to compromise climate-smart conservation efforts. Here, we use a well-established conservation planning framework to show how integrating human responses to climate change into both species- and site-based vulnerability assessments and adaptation plans is possible. By explicitly taking into account human responses, conservation practitioners will improve their evaluation of species and ecosystem vulnerability, and will be better able to deliver win-wins for human- and biodiversity-focused climate adaptation.

  13. Plans, Projections and Practitioners: Engaging with Communities to Explore Adaptation Strategies for Transportation Infrastructure

    NASA Astrophysics Data System (ADS)

    Picketts, I. M.

    2015-12-01

    Transportation infrastructure is a significant climate change adaptation concern because it is: costly; designed for long operational lives; susceptible to both episodic and seasonal deterioration; and a significant safety concern. While examples of adaptation exist in transportation design, many communities do not have the capacity to incorporate climate change considerations into infrastructure planning and management. This presentation will overview the process and outcomes of research conducted in collaboration with the communities of Prince George and Squamish, both located in British Columbia (BC), Canada. Previous research in Prince George (in northern BC) involved applying downscaled climate projection information to assess local climate impacts, and identified transportation infrastructure as the top priority for ongoing study. In Prince George the adaptation process was oriented toward determining how the City could plan, design, and maintain roads and other structures to account for climate change. A local steering committee was formed, and created and evaluated 23 potential research topics. Two focus areas were selected for further investigation and explored during a workshop with practitioners, researchers, consultants and other representatives. The workshop precipitated additional modelling of projected impacts of climate change on road maintenance and road safety, and plans to explore the viability of alternative paving techniques. Outcomes of the case study provide insights regarding how researchers can 'combine' top down and bottom up approaches by using modelling information as part of an engagement process with local experts to explore adaptation. Ongoing research in Squamish seeks to apply lessons learned from the Prince George case study (both related to process and the application of modelling information) to a more temperate coastal region with a more climate-concerned population. In Squamish there also lies an opportunity to explicitly focus

  14. Climate Hazard Assessment for Stakeholder Adaptation Planning in New York City

    NASA Technical Reports Server (NTRS)

    Horton, Radley M.; Gornitz, Vivien; Bader, Daniel A.; Ruane, Alex C.; Goldberg, Richard; Rosenzweig, Cynthia

    2011-01-01

    This paper describes a time-sensitive approach to climate change projections, developed as part of New York City's climate change adaptation process, that has provided decision support to stakeholders from 40 agencies, regional planning associations, and private companies. The approach optimizes production of projections given constraints faced by decision makers as they incorporate climate change into long-term planning and policy. New York City stakeholders, who are well-versed in risk management, helped pre-select the climate variables most likely to impact urban infrastructure, and requested a projection range rather than a single 'most likely' outcome. The climate projections approach is transferable to other regions and consistent with broader efforts to provide climate services, including impact, vulnerability, and adaptation information. The approach uses 16 Global Climate Models (GCMs) and three emissions scenarios to calculate monthly change factors based on 30-year average future time slices relative to a 30- year model baseline. Projecting these model mean changes onto observed station data for New York City yields dramatic changes in the frequency of extreme events such as coastal flooding and dangerous heat events. Based on these methods, the current 1-in-10 year coastal flood is projected to occur more than once every 3 years by the end of the century, and heat events are projected to approximately triple in frequency. These frequency changes are of sufficient magnitude to merit consideration in long-term adaptation planning, even though the precise changes in extreme event frequency are highly uncertain

  15. Comparison of three IMRT inverse planning techniques that allow for partial esophagus sparing in patients receiving thoracic radiation therapy for lung cancer.

    PubMed

    Xiao, Ying; Werner-Wasik, Maria; Michalski, D; Houser, C; Bednarz, G; Curran, W; Galvin, James

    2004-01-01

    The purpose of this study is to compare 3 intensity-modulated radiation therapy (IMRT) inverse treatment planning techniques as applied to locally-advanced lung cancer. This study evaluates whether sufficient radiotherapy (RT) dose is given for durable control of tumors while sparing a portion of the esophagus, and whether large number of segments and monitor units are required. We selected 5 cases of locally-advanced lung cancer with large central tumor, abutting the esophagus. To ensure that no more than half of the esophagus circumference at any level received the specified dose limit, it was divided into disk-like sections and dose limits were imposed on each. Two sets of dose objectives were specified for tumor and other critical structures for standard dose RT and for dose escalation RT. Plans were generated using an aperture-based inverse planning (ABIP) technique with the Cimmino algorithm for optimization. Beamlet-based inverse treatment planning was carried out with a commercial simulated annealing package (CORVUS) and with an in-house system that used the Cimmino projection algorithm (CIMM). For 3 of the 5 cases, results met all of the constraints from the 3 techniques for the 2 sets of dose objectives. The CORVUS system without delivery efficiency consideration required the most segments and monitor units. The CIMM system reduced the number while the ABIP techniques showed a further reduction, although for one of the cases, a solution was not readily obtained using the ABIP technique for dose escalation objectives. PMID:15324918

  16. Adaptive Management Plan for Sensitive Plant Species on the Nevada Test Site

    SciTech Connect

    C. A. Wills

    2001-03-01

    The Nevada Test Site supports numerous plant species considered sensitive because of their past or present status under the Endangered Species Act and with federal and state agencies. In 1998, the U.S. Department of Energy, Nevada Operation Office (DOE/NV) prepared a Resource Management Plan which commits to protects and conserve these sensitive plant species and to minimize accumulative impacts to them. This document presents the procedures of a long-term adaptive management plan which is meant to ensure that these goals are met. It identifies the parameters that are measured for all sensitive plant populations during long-term monitoring and the adaptive management actions which may be taken if significant threats to these populations are detected. This plan does not, however, identify the current list of sensitive plant species know to occur on the Nevada Test Site. The current species list and progress on their monitoring is reported annually by DOE/NV in the Resource Management Plan.

  17. Cyclone preparedness and response: an analysis of lessons identified using an adapted military planning framework.

    PubMed

    Tatham, Peter; Oloruntoba, Richard; Spens, Karen

    2012-01-01

    The United Kingdom uses the Defence Lines of Development (DLOD) framework to analyse and understand the key components and costs of a military capability. Rooted in the Resource Based View (RBV) of a firm, an adapted DLOD approach is employed to explore, analyse and discuss the preparedness, planning and response strategies of two markedly different countries (Australia and Bangladesh) when faced with a major cyclone event of a comparable size. Given the numerous similarities in the challenges facing military forces in a complex emergency and humanitarian agencies in a natural disaster, the paper demonstrates the applicability of the DLOD framework as an analysis and planning tool in the cyclone preparedness planning and response phases, and more broadly within the disaster management area. In addition, the paper highlights the benefit to disaster managers, policymakers and researchers of exploiting comparative cross-learning opportunities from disaster events, drawn from different sectors and countries.

  18. Integrated Modeling and Participatory Scenario Planning for Climate Adaptation: the Maui Groundwater Project

    NASA Astrophysics Data System (ADS)

    Keener, V. W.; Finucane, M.; Brewington, L.

    2014-12-01

    For the last century, the island of Maui, Hawaii, has been the center of environmental, agricultural, and legal conflict with respect to surface and groundwater allocation. Planning for adequate future freshwater resources requires flexible and adaptive policies that emphasize partnerships and knowledge transfer between scientists and non-scientists. In 2012 the Hawai'i state legislature passed the Climate Change Adaptation Priority Guidelines (Act 286) law requiring county and state policy makers to include island-wide climate change scenarios in their planning processes. This research details the ongoing work by researchers in the NOAA funded Pacific RISA to support the development of Hawaii's first island-wide water use plan under the new climate adaptation directive. This integrated project combines several models with participatory future scenario planning. The dynamically downscaled triply nested Hawaii Regional Climate Model (HRCM) was modified from the WRF community model and calibrated to simulate the many microclimates on the Hawaiian archipelago. For the island of Maui, the HRCM was validated using 20 years of hindcast data, and daily projections were created at a 1 km scale to capture the steep topography and diverse rainfall regimes. Downscaled climate data are input into a USGS hydrological model to quantify groundwater recharge. This model was previously used for groundwater management, and is being expanded utilizing future climate projections, current land use maps and future scenario maps informed by stakeholder input. Participatory scenario planning began in 2012 to bring together a diverse group of over 50 decision-makers in government, conservation, and agriculture to 1) determine the type of information they would find helpful in planning for climate change, and 2) develop a set of scenarios that represent alternative climate/management futures. This is an iterative process, resulting in flexible and transparent narratives at multiple scales

  19. A need for planned adaptation to climate change in the wine industry

    NASA Astrophysics Data System (ADS)

    Metzger, Marc J.; Rounsevell, Mark D. A.

    2011-09-01

    The diversity of wine production depends on subtle differences in microclimate and is therefore especially sensitive to climate change. A warmer climate will impact directly on wine-grapes through over-ripening, drying out, rising acidity levels, and greater vulnerability to pests and disease, resulting in changes in wine quality (e.g. complexity, balance and structure) or potentially the style of wine that can be produced. The growing scientific evidence for significant climate change in the coming decades means that adaptation will be of critical importance to the multi-billion dollar global wine-industry in general, and to quality wine producers in particular (White et al 2006, 2009; Hertsgaard 2011). Adaptation is understood as an adjustment in natural or human systems in response to actual or expected environmental change, which moderates harm or exploits beneficial opportunities (IPCC 2007). Autonomous adaptation has been an integral part of the 20th century wine industry. Technological advances, changes in consumer demand, and global competition have meant that growers and producers have had to adapt to stay in business. The gradual temperature rise in the 20th Century (0.7 °C globally) has been accommodated successfully by gradual changes in vine management, technological measures, production control, and marketing (White et al 2009), although this has in many cases resulted in the production of bolder, more alcoholic wines (Hertsgaard 2011). In spite of this success, the wine industry is surprisingly conservative when it comes to considering longer term planned adaptation for substantial climate change impacts. A few producers are expanding to new locations at higher altitudes or cooler climates (e.g. Torres is developing new vineyards high in the Pyrenees, and Mouton Rothschild is setting up new vineyards in South America), and the legal and cultural restrictions of Appelation d'Origine Cȏntrollée (AOC) systems are being discussed (White et al 2009

  20. Exploring factors influencing farmers' willingness to pay (WTP) for a planned adaptation programme to address climatic issues in agricultural sectors.

    PubMed

    Ahmed, Adeel; Masud, Muhammad Mehedi; Al-Amin, Abul Quasem; Yahaya, Siti Rohani Binti; Rahman, Mahfuzur; Akhtar, Rulia

    2015-06-01

    This study empirically estimates farmers' willingness to pay (WTP) for a planned adaptation programme for addressing climate issues in Pakistan's agricultural sectors. The contingent valuation method (CVM) was employed to determine a monetary valuation of farmers' preferences for a planned adaptation programme by ascertaining the value attached to address climatic issues. The survey was conducted by distributing structured questionnaires among Pakistani farmers. The study found that 67 % of respondents were willing to pay for a planned adaptation programme. However, several socioeconomic and motivational factors exert greater influence on their willingness to pay (WTP). This paper specifies the steps needed for all institutional bodies to better address issues in climate change. The outcomes of this paper will support attempts by policy makers to design an efficient adaptation framework for mitigating and adapting to the adverse impacts of climate change. PMID:25613801

  1. Exploring factors influencing farmers' willingness to pay (WTP) for a planned adaptation programme to address climatic issues in agricultural sectors.

    PubMed

    Ahmed, Adeel; Masud, Muhammad Mehedi; Al-Amin, Abul Quasem; Yahaya, Siti Rohani Binti; Rahman, Mahfuzur; Akhtar, Rulia

    2015-06-01

    This study empirically estimates farmers' willingness to pay (WTP) for a planned adaptation programme for addressing climate issues in Pakistan's agricultural sectors. The contingent valuation method (CVM) was employed to determine a monetary valuation of farmers' preferences for a planned adaptation programme by ascertaining the value attached to address climatic issues. The survey was conducted by distributing structured questionnaires among Pakistani farmers. The study found that 67 % of respondents were willing to pay for a planned adaptation programme. However, several socioeconomic and motivational factors exert greater influence on their willingness to pay (WTP). This paper specifies the steps needed for all institutional bodies to better address issues in climate change. The outcomes of this paper will support attempts by policy makers to design an efficient adaptation framework for mitigating and adapting to the adverse impacts of climate change.

  2. IMRT planning on adaptive volume structures--a decisive reduction in computational complexity.

    PubMed

    Scherrer, Alexander; Küfer, Karl-Heinz; Bortfeld, Thomas; Monz, Michael; Alonso, Fernando

    2005-05-01

    The objective of radiotherapy planning is to find a compromise between the contradictive goals of delivering a sufficiently high dose to the target volume while widely sparing critical structures. The search for such a compromise requires the computation of several plans, which mathematically means solving several optimization problems. In the case of intensity modulated radiotherapy (IMRT) these problems are large-scale, hence the accumulated computational expense is very high. The adaptive clustering method presented in this paper overcomes this difficulty. The main idea is to use a preprocessed hierarchy of aggregated dose-volume information as a basis for individually adapted approximations of the original optimization problems. This leads to a decisively reduced computational expense: numerical experiments on several sets of real clinical data typically show computation times decreased by a factor of about 10. In contrast to earlier work in this field, this reduction in computational complexity will not lead to a loss in accuracy: the adaptive clustering method produces the optimum of the original optimization problem.

  3. The brain uses adaptive internal models of scene statistics for sensorimotor estimation and planning.

    PubMed

    Kwon, Oh-Sang; Knill, David C

    2013-03-12

    Because of uncertainty and noise, the brain should use accurate internal models of the statistics of objects in scenes to interpret sensory signals. Moreover, the brain should adapt its internal models to the statistics within local stimulus contexts. Consider the problem of hitting a baseball. The impoverished nature of the visual information available makes it imperative that batters use knowledge of the temporal statistics and history of previous pitches to accurately estimate pitch speed. Using a laboratory analog of hitting a baseball, we tested the hypothesis that the brain uses adaptive internal models of the statistics of object speeds to plan hand movements to intercept moving objects. We fit Bayesian observer models to subjects' performance to estimate the statistical environments in which subjects' performance would be ideal and compared the estimated statistics with the true statistics of stimuli in an experiment. A first experiment showed that subjects accurately estimated and used the variance of object speeds in a stimulus set to time hitting behavior but also showed serial biases that are suboptimal for stimuli that were uncorrelated over time. A second experiment showed that the strength of the serial biases depended on the temporal correlations within a stimulus set, even when the biases were estimated from uncorrelated stimulus pairs subsampled from the larger set. Taken together, the results show that subjects adapted their internal models of the variance and covariance of object speeds within a stimulus set to plan interceptive movements but retained a bias to positive correlations.

  4. The brain uses adaptive internal models of scene statistics for sensorimotor estimation and planning.

    PubMed

    Kwon, Oh-Sang; Knill, David C

    2013-03-12

    Because of uncertainty and noise, the brain should use accurate internal models of the statistics of objects in scenes to interpret sensory signals. Moreover, the brain should adapt its internal models to the statistics within local stimulus contexts. Consider the problem of hitting a baseball. The impoverished nature of the visual information available makes it imperative that batters use knowledge of the temporal statistics and history of previous pitches to accurately estimate pitch speed. Using a laboratory analog of hitting a baseball, we tested the hypothesis that the brain uses adaptive internal models of the statistics of object speeds to plan hand movements to intercept moving objects. We fit Bayesian observer models to subjects' performance to estimate the statistical environments in which subjects' performance would be ideal and compared the estimated statistics with the true statistics of stimuli in an experiment. A first experiment showed that subjects accurately estimated and used the variance of object speeds in a stimulus set to time hitting behavior but also showed serial biases that are suboptimal for stimuli that were uncorrelated over time. A second experiment showed that the strength of the serial biases depended on the temporal correlations within a stimulus set, even when the biases were estimated from uncorrelated stimulus pairs subsampled from the larger set. Taken together, the results show that subjects adapted their internal models of the variance and covariance of object speeds within a stimulus set to plan interceptive movements but retained a bias to positive correlations. PMID:23440185

  5. Bayesian prestack seismic inversion with a self-adaptive Huber-Markov random-field edge protection scheme

    NASA Astrophysics Data System (ADS)

    Tian, Yu-Kun; Zhou, Hui; Chen, Han-Ming; Zou, Ya-Ming; Guan, Shou-Jun

    2013-12-01

    Seismic inversion is a highly ill-posed problem, due to many factors such as the limited seismic frequency bandwidth and inappropriate forward modeling. To obtain a unique solution, some smoothing constraints, e.g., the Tikhonov regularization are usually applied. The Tikhonov method can maintain a global smooth solution, but cause a fuzzy structure edge. In this paper we use Huber-Markov random-field edge protection method in the procedure of inverting three parameters, P-velocity, S-velocity and density. The method can avoid blurring the structure edge and resist noise. For the parameter to be inverted, the Huber-Markov random-field constructs a neighborhood system, which further acts as the vertical and lateral constraints. We use a quadratic Huber edge penalty function within the layer to suppress noise and a linear one on the edges to avoid a fuzzy result. The effectiveness of our method is proved by inverting the synthetic data without and with noises. The relationship between the adopted constraints and the inversion results is analyzed as well.

  6. Revealing Risks in Adaptation Planning: expanding Uncertainty Treatment and dealing with Large Projection Ensembles during Planning Scenario development

    NASA Astrophysics Data System (ADS)

    Brekke, L. D.; Clark, M. P.; Gutmann, E. D.; Wood, A.; Mizukami, N.; Mendoza, P. A.; Rasmussen, R.; Ikeda, K.; Pruitt, T.; Arnold, J. R.; Rajagopalan, B.

    2015-12-01

    Adaptation planning assessments often rely on single methods for climate projection downscaling and hydrologic analysis, do not reveal uncertainties from associated method choices, and thus likely produce overly confident decision-support information. Recent work by the authors has highlighted this issue by identifying strengths and weaknesses of widely applied methods for downscaling climate projections and assessing hydrologic impacts. This work has shown that many of the methodological choices made can alter the magnitude, and even the sign of the climate change signal. Such results motivate consideration of both sources of method uncertainty within an impacts assessment. Consequently, the authors have pursued development of improved downscaling techniques spanning a range of method classes (quasi-dynamical and circulation-based statistical methods) and developed approaches to better account for hydrologic analysis uncertainty (multi-model; regional parameter estimation under forcing uncertainty). This presentation summarizes progress in the development of these methods, as well as implications of pursuing these developments. First, having access to these methods creates an opportunity to better reveal impacts uncertainty through multi-method ensembles, expanding on present-practice ensembles which are often based only on emissions scenarios and GCM choices. Second, such expansion of uncertainty treatment combined with an ever-expanding wealth of global climate projection information creates a challenge of how to use such a large ensemble for local adaptation planning. To address this challenge, the authors are evaluating methods for ensemble selection (considering the principles of fidelity, diversity and sensitivity) that is compatible with present-practice approaches for abstracting change scenarios from any "ensemble of opportunity". Early examples from this development will also be presented.

  7. Adaptation of the Resource Room Version of the Career Planning System for Use with Microcomputers. Final Report.

    ERIC Educational Resources Information Center

    Long, James P.; Neuman, Delia

    An 18-month project was conducted to adapt the resource room version of the National Center for Research in Vocational Education's Career Planning System (CPS) for delivery through microcomputers. Specific goals of the project were as follows: to adapt a print-based product previously found successful with middle school students who displayed mild…

  8. Incorporating Natural Capital into Climate Adaptation Planning: Exploring the Role of Habitat in Increasing Coastal Resilience

    NASA Astrophysics Data System (ADS)

    Wedding, L.; Hartge, E. H.; Guannel, G.; Melius, M.; Reiter, S. M.; Ruckelshaus, M.; Guerry, A.; Caldwell, M.

    2014-12-01

    To support decision-makers in their efforts to manage coastal resources in a changing climate the Natural Capital Project and the Center for Ocean Solutions are engaging in, informing, and helping to shape climate adaptation planning at various scales throughout coastal California. Our team is building collaborations with regional planners and local scientific and legal experts to inform local climate adaptation decisions that might minimize the economic and social losses associated with rising seas and more damaging storms. Decision-makers are considering engineered solutions (e.g. seawalls), natural solutions (e.g. dune or marsh restoration), and combinations of the two. To inform decisions about what kinds of solutions might best work in specific locations, we are comparing alternate climate and adaptation scenarios. We will present results from our use of the InVEST ecosystem service models in Sonoma County, with an initial focus on protection from coastal hazards due to erosion and inundation. By strategically choosing adaptation alternatives, communities and agencies can work to protect people and property while also protecting or restoring dwindling critical habitat and the full suite of benefits those habitats provide to people.

  9. 78 FR 9387 - Notice of Availability for Public Review and Comment: Draft EPA Climate Change Adaptation Plan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-08

    ... involve anticipating and planning for changes in climate and incorporating considerations of climate... Agency Climate Change Adaptation Plans in response to the President's October 2009 Executive Order (E.O... health and the environment. Many of the goals EPA is working to attain (e.g., clean air, safe...

  10. Participatory Scenario Planning for Climate Change Adaptation: the Maui Groundwater Project

    NASA Astrophysics Data System (ADS)

    Keener, V. W.; Brewington, L.; Finucane, M.

    2015-12-01

    For the last century, the island of Maui in Hawai'i has been the center of environmental, agricultural, and legal conflict with respect to both surface and groundwater allocation. Planning for sustainable future freshwater supply in Hawai'i requires adaptive policies and decision-making that emphasizes private and public partnerships and knowledge transfer between scientists and non-scientists. We have downscaled dynamical climate models to 1 km resolution in Maui and coupled them with a USGS Water Budget model and a participatory scenario building process to quantify future changes in island-scale climate and groundwater recharge under different land uses. Although these projections are uncertain, the integrated nature of the Pacific RISA research program has allowed us to take a multi-pronged approach to facilitate the uptake of climate information into policy and management. This presentation details the ongoing work to support the development of Hawai'i's first island-wide water use plan under the new climate adaptation directive. Participatory scenario planning began in 2012 to bring together a diverse group of ~100 decision-makers in state and local government, watershed restoration, agriculture, and conservation to 1) determine the type of information (climate variables, land use and development, agricultural practices) they would find helpful in planning for climate change, and 2) develop a set of nested scenarios that represent alternative climate and management futures. This integration of knowledge is an iterative process, resulting in flexible and transparent narratives of complex futures comprised of information at multiple scales. We will present an overview of the downscaling, scenario building, hydrological modeling processes, and stakeholder response.

  11. State Wildlife Action Plans as Tools for Adapting to a Continuously Changing Climate

    NASA Astrophysics Data System (ADS)

    Metivier, D. W.; Yocum, H.; Ray, A. J.

    2015-12-01

    Public land management plans are potentially powerful policies for building sustainability and adaptive capacity. Land managers are recognizing the need to respond to numerous climate change impacts on natural and human systems. For the first time, in 2015, the federal government required each state to incorporate climate change into their State Wildlife Action Plans (SWAP) as a condition for funding. As important land management tools, SWAPs have the potential to guide state agencies in shaping and implementing practices for climate change adaptation. Intended to be revised every ten years, SWAPs can change as conditions and understanding of climate change evolves. This study asks what practices are states using to integrate climate change, and how does this vary between states? To answer this question, we conducted a broad analysis among seven states (CO, MT, NE, ND, SD, UT, WY) and a more in-depth analysis of four states (CO, ND, SD, WY). We use seven key factors that represent best practices for incorporating climate change identified in the literature. These best practices are species prioritization, key habitats, threats, monitoring, partnerships and participation, identification of management options, and implementation of management options. The in-depth analysis focuses on how states are using climate change information for specific habitats addressed in the plans. We find that states are integrating climate change in many different ways, showing varying degrees of sophistication and preparedness. We summarize different practices and highlight opportunities to improve the effectiveness of plans through: communication tools across state lines and stakeholders, explicit targeting of key habitats, enforcement and monitoring progress and success, and conducting vulnerability analyses that incorporate topics beyond climate and include other drivers, trajectories, and implications of historic and future land-use change.

  12. A-T linker adapter polymerase chain reaction for determining flanking sequences by rescuing inverse PCR or thermal asymmetric interlaced PCR products.

    PubMed

    Trinh, Quoclinh; Zhu, Pengyu; Shi, Hui; Xu, Wentao; Hao, Junran; Luo, Yunbo; Huang, Kunlun

    2014-12-01

    The polymerase chain reaction (PCR)-based genome walking method has been extensively used to isolate unknown flanking sequences, whereas nonspecific products are always inevitable. To resolve these problems, we developed a new strategy to isolate the unknown flanking sequences by combining A-T linker adapter PCR with inverse PCR (I-PCR) or thermal asymmetric interlaced PCR (TAIL-PCR). The result showed that this method can be efficiently achieved with the flanking sequence from the Arabidopsis mutant and papain gene. Our study provides researchers with an additional method for determining genomic DNA flanking sequences to identify the target band from bulk of bands and to eliminate the cloning step for sequencing.

  13. The adaptation of megavoltage cone beam CT for use in standard radiotherapy treatment planning

    NASA Astrophysics Data System (ADS)

    Thomas, T. Hannah Mary; Devakumar, D.; Purnima, S.; Ravindran, B. Paul

    2009-04-01

    Potential areas where megavoltage computed tomography (MVCT) could be used are second- and third-phase treatment planning in 3D conformal radiotherapy and IMRT, adaptive radiation therapy, single fraction palliative treatment and for the treatment of patients with metal prostheses. A feasibility study was done on using MV cone beam CT (CBCT) images generated by proprietary 3D reconstruction software based on the FDK algorithm for megavoltage treatment planning. The reconstructed images were converted to a DICOM file set. The pixel values of megavoltage cone beam computed tomography (MV CBCT) were rescaled to those of kV CT for use with a treatment planning system. A calibration phantom was designed and developed for verification of geometric accuracy and CT number calibration. The distance measured between two marker points on the CBCT image and the physical dimension on the phantom were in good agreement. Point dose verification for a 10 cm × 10 cm beam at a gantry angle of 0° and SAD of 100 cm were performed for a 6 MV beam for both kV and MV CBCT images. The point doses were found to vary between ±6.1% of the dose calculated from the kV CT image. The isodose curves for 6 MV for both kV CT and MV CBCT images were within 2% and 3 mm distance-to-agreement. A plan with three beams was performed on MV CBCT, simulating a treatment plan for cancer of the pituitary. The distribution obtained was compared with those corresponding to that obtained using the kV CT. This study has shown that treatment planning with MV cone beam CT images is feasible.

  14. Ecologically-Relevant Maps of Landforms and Physiographic Diversity for Climate Adaptation Planning.

    PubMed

    Theobald, David M; Harrison-Atlas, Dylan; Monahan, William B; Albano, Christine M

    2015-01-01

    Key to understanding the implications of climate and land use change on biodiversity and natural resources is to incorporate the physiographic platform on which changes in ecological systems unfold. Here, we advance a detailed classification and high-resolution map of physiography, built by combining landforms and lithology (soil parent material) at multiple spatial scales. We used only relatively static abiotic variables (i.e., excluded climatic and biotic factors) to prevent confounding current ecological patterns and processes with enduring landscape features, and to make the physiographic classification more interpretable for climate adaptation planning. We generated novel spatial databases for 15 landform and 269 physiographic types across the conterminous United States of America. We examined their potential use by natural resource managers by placing them within a contemporary climate change adaptation framework, and found our physiographic databases could play key roles in four of seven general adaptation strategies. We also calculated correlations with common empirical measures of biodiversity to examine the degree to which the physiographic setting explains various aspects of current biodiversity patterns. Additionally, we evaluated the relationship between landform diversity and measures of climate change to explore how changes may unfold across a geophysical template. We found landform types are particularly sensitive to spatial scale, and so we recommend using high-resolution datasets when possible, as well as generating metrics using multiple neighborhood sizes to both minimize and characterize potential unknown biases. We illustrate how our work can inform current strategies for climate change adaptation. The analytical framework and classification of landforms and parent material are easily extendable to other geographies and may be used to promote climate change adaptation in other settings.

  15. Ecologically-Relevant Maps of Landforms and Physiographic Diversity for Climate Adaptation Planning

    PubMed Central

    Theobald, David M.; Harrison-Atlas, Dylan; Monahan, William B.; Albano, Christine M.

    2015-01-01

    Key to understanding the implications of climate and land use change on biodiversity and natural resources is to incorporate the physiographic platform on which changes in ecological systems unfold. Here, we advance a detailed classification and high-resolution map of physiography, built by combining landforms and lithology (soil parent material) at multiple spatial scales. We used only relatively static abiotic variables (i.e., excluded climatic and biotic factors) to prevent confounding current ecological patterns and processes with enduring landscape features, and to make the physiographic classification more interpretable for climate adaptation planning. We generated novel spatial databases for 15 landform and 269 physiographic types across the conterminous United States of America. We examined their potential use by natural resource managers by placing them within a contemporary climate change adaptation framework, and found our physiographic databases could play key roles in four of seven general adaptation strategies. We also calculated correlations with common empirical measures of biodiversity to examine the degree to which the physiographic setting explains various aspects of current biodiversity patterns. Additionally, we evaluated the relationship between landform diversity and measures of climate change to explore how changes may unfold across a geophysical template. We found landform types are particularly sensitive to spatial scale, and so we recommend using high-resolution datasets when possible, as well as generating metrics using multiple neighborhood sizes to both minimize and characterize potential unknown biases. We illustrate how our work can inform current strategies for climate change adaptation. The analytical framework and classification of landforms and parent material are easily extendable to other geographies and may be used to promote climate change adaptation in other settings. PMID:26641818

  16. Ecologically-Relevant Maps of Landforms and Physiographic Diversity for Climate Adaptation Planning.

    PubMed

    Theobald, David M; Harrison-Atlas, Dylan; Monahan, William B; Albano, Christine M

    2015-01-01

    Key to understanding the implications of climate and land use change on biodiversity and natural resources is to incorporate the physiographic platform on which changes in ecological systems unfold. Here, we advance a detailed classification and high-resolution map of physiography, built by combining landforms and lithology (soil parent material) at multiple spatial scales. We used only relatively static abiotic variables (i.e., excluded climatic and biotic factors) to prevent confounding current ecological patterns and processes with enduring landscape features, and to make the physiographic classification more interpretable for climate adaptation planning. We generated novel spatial databases for 15 landform and 269 physiographic types across the conterminous United States of America. We examined their potential use by natural resource managers by placing them within a contemporary climate change adaptation framework, and found our physiographic databases could play key roles in four of seven general adaptation strategies. We also calculated correlations with common empirical measures of biodiversity to examine the degree to which the physiographic setting explains various aspects of current biodiversity patterns. Additionally, we evaluated the relationship between landform diversity and measures of climate change to explore how changes may unfold across a geophysical template. We found landform types are particularly sensitive to spatial scale, and so we recommend using high-resolution datasets when possible, as well as generating metrics using multiple neighborhood sizes to both minimize and characterize potential unknown biases. We illustrate how our work can inform current strategies for climate change adaptation. The analytical framework and classification of landforms and parent material are easily extendable to other geographies and may be used to promote climate change adaptation in other settings. PMID:26641818

  17. Successful adaptation of three-dimensional inversion methodologies for archaeological-scale, total-field magnetic data sets

    NASA Astrophysics Data System (ADS)

    Cheyney, S.; Fishwick, S.; Hill, I. A.; Linford, N. T.

    2015-08-01

    Despite the development of advanced processing and interpretation tools for magnetic data sets in the fields of mineral and hydrocarbon industries, these methods have not achieved similar levels of adoption for archaeological or very near surface surveys. Using a synthetic data set we demonstrate that certain methodologies and assumptions used to successfully invert more regional-scale data can lead to large discrepancies between the true and recovered depths when applied to archaeological-type anomalies. We propose variations to the current approach, analysing the choice of the depth-weighting function, mesh design and parameter constraints, to develop an appropriate technique for the 3-D inversion of archaeological-scale data sets. The results show a successful recovery of a synthetic scenario, as well as a case study of a Romano-Celtic temple in the UK. For the case study, the final susceptibility model is compared with two coincident ground penetrating radar surveys, showing a high correlation with the comparative depth slices. The new approach takes interpretation of archaeological data sets beyond a simple 2-D visual interpretation based on pattern recognition.

  18. Multi-optimization Criteria-based Robot Behavioral Adaptability and Motion Planning

    SciTech Connect

    Pin, Francois G.

    2002-06-01

    Robotic tasks are typically defined in Task Space (e.g., the 3-D World), whereas robots are controlled in Joint Space (motors). The transformation from Task Space to Joint Space must consider the task objectives (e.g., high precision, strength optimization, torque optimization), the task constraints (e.g., obstacles, joint limits, non-holonomic constraints, contact or tool task constraints), and the robot kinematics configuration (e.g., tools, type of joints, mobile platform, manipulator, modular additions, locked joints). Commercially available robots are optimized for a specific set of tasks, objectives and constraints and, therefore, their control codes are extremely specific to a particular set of conditions. Thus, there exist a multiplicity of codes, each handling a particular set of conditions, but none suitable for use on robots with widely varying tasks, objectives, constraints, or environments. On the other hand, most DOE missions and tasks are typically ''batches of one''. Attempting to use commercial codes for such work requires significant personnel and schedule costs for re-programming or adding code to the robots whenever a change in task objective, robot configuration, number and type of constraint, etc. occurs. The objective of our project is to develop a ''generic code'' to implement this Task-space to Joint-Space transformation that would allow robot behavior adaptation, in real time (at loop rate), to changes in task objectives, number and type of constraints, modes of controls, kinematics configuration (e.g., new tools, added module). Our specific goal is to develop a single code for the general solution of under-specified systems of algebraic equations that is suitable for solving the inverse kinematics of robots, is useable for all types of robots (mobile robots, manipulators, mobile manipulators, etc.) with no limitation on the number of joints and the number of controlled Task-Space variables, can adapt to real time changes in number and

  19. Influences on Adaptive Planning to Reduce Flood Risks among Parishes in South Louisiana

    PubMed Central

    Paille, Mary; Reams, Margaret; Argote, Jennifer; Lam, Nina S.-N.; Kirby, Ryan

    2016-01-01

    Residents of south Louisiana face a range of increasing, climate-related flood exposure risks that could be reduced through local floodplain management and hazard mitigation planning. A major incentive for community planning to reduce exposure to flood risks is offered by the Community Rating System (CRS) of the National Flood Insurance Program (NFIP). The NFIP encourages local collective action by offering reduced flood insurance premiums for individual policy holders of communities where suggested risk-reducing measures have been implemented. This preliminary analysis examines the extent to which parishes (counties) in southern Louisiana have implemented the suggested policy actions and identifies key factors that account for variation in the implementation of the measures. More measures implemented results in higher CRS scores. Potential influences on scores include socioeconomic attributes of residents, government capacity, average elevation and past flood events. The results of multiple regression analysis indicate that higher CRS scores are associated most closely with higher median housing values. Furthermore, higher scores are found in parishes with more local municipalities that participate in the CRS program. The number of floods in the last five years and the revenue base of the parish does not appear to influence CRS scores. The results shed light on the conditions under which local adaptive planning to mitigate increasing flood risks is more likely to be implemented and offer insights for program administrators, researchers and community stakeholders. PMID:27330828

  20. Multiscale registration of planning CT and daily cone beam CT images for adaptive radiation therapy

    SciTech Connect

    Paquin, Dana; Levy, Doron; Xing Lei

    2009-01-15

    Adaptive radiation therapy (ART) is the incorporation of daily images in the radiotherapy treatment process so that the treatment plan can be evaluated and modified to maximize the amount of radiation dose to the tumor while minimizing the amount of radiation delivered to healthy tissue. Registration of planning images with daily images is thus an important component of ART. In this article, the authors report their research on multiscale registration of planning computed tomography (CT) images with daily cone beam CT (CBCT) images. The multiscale algorithm is based on the hierarchical multiscale image decomposition of E. Tadmor, S. Nezzar, and L. Vese [Multiscale Model. Simul. 2(4), pp. 554-579 (2004)]. Registration is achieved by decomposing the images to be registered into a series of scales using the (BV, L{sup 2}) decomposition and initially registering the coarsest scales of the image using a landmark-based registration algorithm. The resulting transformation is then used as a starting point to deformably register the next coarse scales with one another. This procedure is iterated at each stage using the transformation computed by the previous scale registration as the starting point for the current registration. The authors present the results of studies of rectum, head-neck, and prostate CT-CBCT registration, and validate their registration method quantitatively using synthetic results in which the exact transformations our known, and qualitatively using clinical deformations in which the exact results are not known.

  1. Future planning and evaluation for automated adaptive minehunting: a roadmap for mine countermeasures theory modernization

    NASA Astrophysics Data System (ADS)

    Garcia, Gregory A.; Wettergren, Thomas A.

    2012-06-01

    This paper presents a discussion of U.S. naval mine countermeasures (MCM) theory modernization in light of advances in the areas of autonomy, tactics, and sensor processing. The unifying theme spanning these research areas concerns the capability for in situ adaptation of processing algorithms, plans, and vehicle behaviors enabled through run-time situation assessment and performance estimation. Independently, each of these technology developments impact the MCM Measures of Effectiveness1 [MOE(s)] of time and risk by improving one or more associated Measures of Performance2 [MOP(s)]; the contribution of this paper is to outline an integrated strategy for realizing the cumulative benefits of these technology enablers to the United States Navy's minehunting capability. An introduction to the MCM problem is provided to frame the importance of the foundational research and the ramifications of the proposed strategy on the MIW community. We then include an overview of current and future adaptive capability research in the aforementioned areas, highlighting a departure from the existing rigid assumption-based approaches while identifying anticipated technology acceptance issues. Consequently, the paper describes an incremental strategy for transitioning from the current minehunting paradigm where tactical decision aids rely on a priori intelligence and there is little to no in situ adaptation or feedback to a future vision where unmanned systems3, equipped with a representation of the commander's intent, are afforded the authority and ability to adapt to environmental perturbations with minimal human-in-the-loop supervision. The discussion concludes with an articulation of the science and technology issues which the MCM research community must continue to address.

  2. Offline multiple adaptive planning strategy for concurrent irradiation of the prostate and pelvic lymph nodes

    SciTech Connect

    Qi, Peng; Xia, Ping; Pouliot, Jean; Roach, Mack

    2014-02-15

    Purpose: Concurrent irradiation of the prostate and pelvic lymph nodes (PLNs) can be challenging due to the independent motion of the two target volumes. To address this challenge, the authors have proposed a strategy referred to as Multiple Adaptive Planning (MAP). To minimize the number of MAP plans, the authors’ previous work only considered the prostate motion in one major direction. After analyzing the pattern of the prostate motion, the authors investigated a practical number of intensity-modulated radiotherapy (IMRT) plans needed to accommodate the prostate motion in two major directions simultaneously. Methods: Six patients, who received concurrent irradiation of the prostate and PLNs, were selected for this study. Nine MAP-IMRT plans were created for each patient with nine prostate contours that represented the prostate at nine locations with respect to the PLNs, including the original prostate contour and eight contours shifted either 5 mm in a single anterior-posterior (A-P), or superior-inferior (S-I) direction, or 5 mm in both A-P and S-I directions simultaneously. From archived megavoltage cone beam CT (MV-CBCT) and a dual imaging registration, 17 MV-CBCTs from 33 available MV-CBCT from these patients showed large prostate displacements (>3 mm in any direction) with respect to the pelvic bones. For each of these 17 fractions, one of nine MAP-IMRT plans was retrospectively selected and applied to the MV-CBCT for dose calculation. For comparison, a simulated isocenter-shifting plan and a reoptimized plan were also created for each of these 17 fractions. The doses to 95% (D95) of the prostate and PLNs, and the doses to 5% (D5) of the rectum and bladder were calculated and analyzed. Results: For the prostate, D95 > 97% of the prescription dose was observed in 16, 16, and 17 of 17 fractions for the MAP, isocenter-shifted, and reoptimized plans, respectively. For PLNs, D95 > 97% of the prescription doses was observed in 10, 3, and 17 of 17 fractions for

  3. Mapping Heat-related Risks for Community-based Adaptation Planning under Uncertainty

    NASA Astrophysics Data System (ADS)

    Bai, Yingjiu; Kaneko, Ikuyo; Kobayashi, Hikaru; Kurihara, Kazuo; Sasaki, Hidetaka; Murata, Akihiko; Takayabu, Izuru

    2016-04-01

    Climate change is leading to more frequent and intense heat waves. Recently, epidemiologic findings on heat-related health impacts have reinforced our understanding of the mortality impacts of extreme heat. This research has several aims: 1) to promote climate prediction services with spatial and temporal information on heat-related risks, using GIS (Geographical Information System), and digital mapping techniques; 2) to propose a visualization approach to articulating the evolution of local heat-health responses over time and the evaluation of new interventions for the implementation of valid community-based adaptation strategies and reliable actionable planning; and 3) to provide an appropriate and simple method of adjusting bias and quantifying the uncertainty in future outcomes, so that regional climate projections may be transcribed into useful forms for a wide variety of different users. Following the 2003 European heat wave, climatologists, medical specialists, and social scientists expedited efforts to revise and integrate risk governance frameworks for communities to take appropriate and effective actions themselves. Recently, the Coupled Model Intercomparison Project (CMIP) methodology has made projections possible for anyone wanting to openly access state-of-the-art climate model outputs and climate data to provide the backbone for decisions. Furthermore, the latest high-solution regional climate model (RCM) has been a huge increase in the volumes of data available. In this study, we used high-quality hourly projections (5-km resolution) from the Non-Hydrostatic Regional Climate Model (NHRCM-5km), following the SRES-A1B scenario developed by the Meteorological Research Institute (MRI) and observational data from the Automated Meteorological Data Acquisition System, Japan Meteorological Agency (JMA). The NHRCM-5km is a dynamic downscaling of results from the MRI-AGCM3.2S (20-km resolution), an atmospheric general circulation model (AGCM) driven by the

  4. Evaluation of Multiple Breathing States Using a Multiple Instance Geometry Approximation (MIGA) in Inverse-Planned Optimization for Locoregional Breast Treatment

    SciTech Connect

    Lin, Alexander; Moran, Jean M.; Marsh, Robin B.; Balter, James M.; Fraass, Benedick A.; McShan, Daniel L.; Kessler, Marc L.; Pierce, Lori J.

    2008-10-01

    Purpose: Although previous work demonstrated superior dose distributions for left-sided breast cancer patients planned for intensity-modulated radiation therapy (IMRT) at deep inspiration breath hold compared with conventional techniques with free-breathing, such techniques are not always feasible to limit the impact of respiration on treatment delivery. This study assessed whether optimization based on multiple instance geometry approximation (MIGA) could derive an IMRT plan that is less sensitive to known respiratory motions. Methods and Materials: CT scans were acquired with an active breathing control device at multiple breath-hold states. Three inverse optimized plans were generated for eight left-sided breast cancer patients: one static IMRT plan optimized at end exhale, two (MIGA) plans based on a MIGA representation of normal breathing, and a MIGA representation of deep breathing, respectively. Breast and nodal targets were prescribed 52.2 Gy, and a simultaneous tumor bed boost was prescribed 60 Gy. Results: With normal breathing, doses to the targets, heart, and left anterior descending (LAD) artery were equivalent whether optimizing with MIGA or on a static data set. When simulating motion due to deep breathing, optimization with MIGA appears to yield superior tumor-bed coverage, decreased LAD mean dose, and maximum heart and LAD dose compared with optimization on a static representation. Conclusions: For left-sided breast-cancer patients, inverse-based optimization accounting for motion due to normal breathing may be similar to optimization on a static data set. However, some patients may benefit from accounting for deep breathing with MIGA with improvements in tumor-bed coverage and dose to critical structures.

  5. Scenario Planning Provides a Framework for Climate Change Adaptation in the National Park Service

    NASA Astrophysics Data System (ADS)

    Welling, L. A.

    2012-12-01

    Resource management decisions must be based on future expectations. Abundant evidence suggests climate change will have highly consequential effects on the Nation's natural and cultural resources, but specific impacts are difficult to accurately predict. This situation of too much information but not enough specificity can often lead to either paralysis or denial for decision makers. Scenario planning is an emerging tool for climate change adaptation that provides a structured framework for identifying and exploring critical drivers of change and their uncertain outcomes. Since 2007, the National Park Service (NPS) has been working with its partners to develop and apply a scenario-based approach for adaptation planning that integrates quantitative, model-driven, climate change projections with qualitative, participatory exercises to explore management and policy options under a range of future conditions. Major outcomes of this work are (1) increased understanding of key scientific results and uncertainties, (2) incorporation of alternative perspectives into park and landscape level planning, (3) identification of "no brainer" and "no gainer" actions, (4) strengthening of regional science-management partnerships, and (5) overall improved capacity for flexible decision making. The basic approach employed by NPS for scenario planning follows a typical adaptive management process: define the focal question, assess the relevant science, explore plausible futures, identify effective strategies, prioritize and implement actions, and monitor results. Many science and management partners contributed to the process, including NOAA Regional Integrated Science and Assessment teams (RISAs) and Regional Climate Centers (RCCs), USGS Research Centers, and other university and government scientists. The Global Business Network, an internationally recognized leader in scenario development, provided expert facilitation and training techniques. Climate science input is provided

  6. SU-E-J-52: Dosimetric Benefit of Adaptive Re-Planning in Lung Cancer Stereotactic Body Radiotherapy (SBRT)

    SciTech Connect

    Jia, J; Tian, Z; Gu, X; Yan, H; Jiang, S; Jia, X

    2014-06-01

    Purpose: To investigate the dosimetric benefit of adaptive re-planning for lung stereotactic body radiotherapy(SBRT). Methods: Five lung cancer patients with SBRT treatment were retrospectively investigated. Our in-house supercomputing online re-planning environment (SCORE) was used to realize the re-planning process. First a deformable image registration was carried out to transfer contours from treatment planning CT to each treatment CBCT. Then an automatic re-planning using original plan DVH guided fluence-map optimization is performed to get a new plan for the up-to-date patient geometry. We compared the re-optimized plan to the original plan projected on the up-to-date patient geometry in critical dosimetric parameters, such as PTV coverage, spinal cord maximum and volumetric constraint dose, esophagus maximum and volumetric constraint dose. Results: The average volume of PTV covered by prescription dose for all patients was improved by 7.56% after the adaptive re-planning. The volume of the spinal cord receiving 14.5Gy and 23Gy (V14.5, V23) decreased by 1.48% and 0.68%, respectively. For the esophagus, the volume receiving 19.5Gy (V19.5) reduced by 1.37%. Meanwhile, the maximum dose dropped off by 2.87% for spinal cord and 4.80% for esophagus. Conclusion: Our experimental results demonstrate that adaptive re-planning for lung SBRT has the potential to minimize the dosimetric effect of inter-fraction deformation and thus improve target coverage while reducing the risk of toxicity to nearby normal tissues.

  7. Planning an adaptive management process for biodiversity conservation and resource development in the Camisea River Basin.

    PubMed

    Dallmeier, Francisco; Alonso, Alfonso; Jones, Murray

    2002-05-01

    The Smithsonian Institution's Monitoring and Assessment of Biodiversity Program joined Shell Prospecting and Development Peru (SPDP) to protect biodiversity during a natural gas exploration project. Emphasis was on long-term societal and environmental benefits in addition to financial gain for the company. The systematic, cyclical adaptive management process was used to generate feedback for SPDP managers. Adaptive management enables ongoing improvement of management policies and practices based on lessons learned from operational activities. Previous to this study, very little information about the local biodiversity was available. Over a 2-year period, the team conducted biological assessments of six taxonomic groups at five sites located within 600 km2. A broad range of management options such as location, timing and technology were developed from the beginning of the project. They were considered in conjunction with emerging lessons from the biodiversity assessments. Critical decisions included location of a gas plant and the cost of helicopter access versus roads to service the full field development. Both of these decisions were evaluated to ensure that they were economically and environmentally feasible. Project design changes, addressed in the planning stage, were accepted once consensus was achieved. Stakeholders were apprised of the implications of the baseline biodiversity assessments.

  8. Quality assurance plan for the Objective Supply Capability Adaptive Redesign (OSCAR) project

    SciTech Connect

    Stewart, K.A.; Rasch, K.A.; Reid, R.W.

    1996-11-01

    This document establishes the Quality Assurance Plan (QAP) for the National Guard Bureau Objective Supply Capability Adaptive Redesign (OSCAR) project activities under the Oak Ridge National Laboratory (ORNL) management. It defines the requirements and assigns responsibilities for ensuring, with a high degree of confidence, that project objectives will be achieved as planned. The QAP outlined herein is responsive to and meets the Quality Assurance Program standards for the U.S. Department of Energy (DOE), Lockheed Martin Energy Research Corporation and ORNL and the ORNL Computing, Robotics, and Education Directorate (CRE). This document is intended to be in compliance with DOE Order 5700.6C, Quality Assurance Program, and the ORNL Standard Practice Procedure, SPP X-QA-8, Quality Assurance for ORNL Computing Software. This standard allows individual organizations to apply the stated requirements in a flexible manner suitable to the type of activity involved. Section I of this document provides an introduction to the OSCAR project QAP; Sections 2 and 3 describe the specific aspects of quality assurance as applicable to the OSCAR project. Section 4 describes the project approach to risk management. The Risk Management Matrix given in Appendix A is a tool to assess, prioritize, and prevent problems before they occur. Therefore, the matrix will be reviewed and revised on a periodic basis.

  9. Translation, adaptation and validation the contents of the Diabetes Medical Management Plan for the Brazilian context

    PubMed Central

    Torres, Heloísa de Carvalho; Chaves, Fernanda Figueredo; da Silva, Daniel Dutra Romualdo; Bosco, Adriana Aparecida; Gabriel, Beatriz Diniz; Reis, Ilka Afonso; Rodrigues, Júlia Santos Nunes; Pagano, Adriana Silvina

    2016-01-01

    ABSTRACT Objective: to translate, adapt and validate the contents of the Diabetes Medical Management Plan for the Brazilian context. This protocol was developed by the American Diabetes Association and guides the procedure of educators for the care of children and adolescents with diabetes in schools. Method: this methodological study was conducted in four stages: initial translation, synthesis of initial translation, back translation and content validation by an expert committee, composed of 94 specialists (29 applied linguists and 65 health professionals), for evaluation of the translated version through an online questionnaire. The concordance level of the judges was calculated based on the Content Validity Index. Data were exported into the R program for statistical analysis: Results: the evaluation of the instrument showed good concordance between the judges of the Health and Applied Linguistics areas, with a mean content validity index of 0.9 and 0.89, respectively, and slight variability of the index between groups (difference of less than 0.01). The items in the translated version, evaluated as unsatisfactory by the judges, were reformulated based on the considerations of the professionals of each group. Conclusion: a Brazilian version of Diabetes Medical Management Plan was constructed, called the Plano de Manejo do Diabetes na Escola. PMID:27508911

  10. A hybrid strategy of offline adaptive planning and online image guidance for prostate cancer radiotherapy

    NASA Astrophysics Data System (ADS)

    Lei, Yu; Wu, Qiuwen

    2010-04-01

    Offline adaptive radiotherapy (ART) has been used to effectively correct and compensate for prostate motion and reduce the required margin. The efficacy depends on the characteristics of the patient setup error and interfraction motion through the whole treatment; specifically, systematic errors are corrected and random errors are compensated for through the margins. In online image-guided radiation therapy (IGRT) of prostate cancer, the translational setup error and inter-fractional prostate motion are corrected through pre-treatment imaging and couch correction at each fraction. However, the rotation and deformation of the target are not corrected and only accounted for with margins in treatment planning. The purpose of this study was to investigate whether the offline ART strategy is necessary for an online IGRT protocol and to evaluate the benefit of the hybrid strategy. First, to investigate the rationale of the hybrid strategy, 592 cone-beam-computed tomography (CBCT) images taken before and after each fraction for an online IGRT protocol from 16 patients were analyzed. Specifically, the characteristics of prostate rotation were analyzed. It was found that there exist systematic inter-fractional prostate rotations, and they are patient specific. These rotations, if not corrected, are persistent through the treatment fraction, and rotations detected in early fractions are representative of those in later fractions. These findings suggest that the offline adaptive replanning strategy is beneficial to the online IGRT protocol with further margin reductions. Second, to quantitatively evaluate the benefit of the hybrid strategy, 412 repeated helical CT scans from 25 patients during the course of treatment were included in the replanning study. Both low-risk patients (LRP, clinical target volume, CTV = prostate) and intermediate-risk patients (IRP, CTV = prostate + seminal vesicles) were included in the simulation. The contours of prostate and seminal vesicles were

  11. Adapt

    NASA Astrophysics Data System (ADS)

    Bargatze, L. F.

    2015-12-01

    Active Data Archive Product Tracking (ADAPT) is a collection of software routines that permits one to generate XML metadata files to describe and register data products in support of the NASA Heliophysics Virtual Observatory VxO effort. ADAPT is also a philosophy. The ADAPT concept is to use any and all available metadata associated with scientific data to produce XML metadata descriptions in a consistent, uniform, and organized fashion to provide blanket access to the full complement of data stored on a targeted data server. In this poster, we present an application of ADAPT to describe all of the data products that are stored by using the Common Data File (CDF) format served out by the CDAWEB and SPDF data servers hosted at the NASA Goddard Space Flight Center. These data servers are the primary repositories for NASA Heliophysics data. For this purpose, the ADAPT routines have been used to generate data resource descriptions by using an XML schema named Space Physics Archive, Search, and Extract (SPASE). SPASE is the designated standard for documenting Heliophysics data products, as adopted by the Heliophysics Data and Model Consortium. The set of SPASE XML resource descriptions produced by ADAPT includes high-level descriptions of numerical data products, display data products, or catalogs and also includes low-level "Granule" descriptions. A SPASE Granule is effectively a universal access metadata resource; a Granule associates an individual data file (e.g. a CDF file) with a "parent" high-level data resource description, assigns a resource identifier to the file, and lists the corresponding assess URL(s). The CDAWEB and SPDF file systems were queried to provide the input required by the ADAPT software to create an initial set of SPASE metadata resource descriptions. Then, the CDAWEB and SPDF data repositories were queried subsequently on a nightly basis and the CDF file lists were checked for any changes such as the occurrence of new, modified, or deleted

  12. Adaptation and Validation of the Tower of London Test of Planning and Problem Solving in People with Intellectual Disabilities

    ERIC Educational Resources Information Center

    Masson, J. D.; Dagnan, D.; Evans, J.

    2010-01-01

    Background: There is a need for validated, standardised tools for the assessment of executive functions in adults with intellectual disabilities (ID). This study examines the validity of a test of planning and problem solving (Tower of London) with adults with ID. Method: Participants completed an adapted version of the Tower of London (ToL) while…

  13. A Fully Automated Method for CT-on-Rails-Guided Online Adaptive Planning for Prostate Cancer Intensity Modulated Radiation Therapy

    SciTech Connect

    Li, Xiaoqiang; Quan, Enzhuo M.; Li, Yupeng; Pan, Xiaoning; Zhou, Yin; Wang, Xiaochun; Du, Weiliang; Kudchadker, Rajat J.; Johnson, Jennifer L.; Kuban, Deborah A.; Lee, Andrew K.; Zhang, Xiaodong

    2013-08-01

    Purpose: This study was designed to validate a fully automated adaptive planning (AAP) method which integrates automated recontouring and automated replanning to account for interfractional anatomical changes in prostate cancer patients receiving adaptive intensity modulated radiation therapy (IMRT) based on daily repeated computed tomography (CT)-on-rails images. Methods and Materials: Nine prostate cancer patients treated at our institution were randomly selected. For the AAP method, contours on each repeat CT image were automatically generated by mapping the contours from the simulation CT image using deformable image registration. An in-house automated planning tool incorporated into the Pinnacle treatment planning system was used to generate the original and the adapted IMRT plans. The cumulative dose–volume histograms (DVHs) of the target and critical structures were calculated based on the manual contours for all plans and compared with those of plans generated by the conventional method, that is, shifting the isocenters by aligning the images based on the center of the volume (COV) of prostate (prostate COV-aligned). Results: The target coverage from our AAP method for every patient was acceptable, while 1 of the 9 patients showed target underdosing from prostate COV-aligned plans. The normalized volume receiving at least 70 Gy (V{sub 70}), and the mean dose of the rectum and bladder were reduced by 8.9%, 6.4 Gy and 4.3%, 5.3 Gy, respectively, for the AAP method compared with the values obtained from prostate COV-aligned plans. Conclusions: The AAP method, which is fully automated, is effective for online replanning to compensate for target dose deficits and critical organ overdosing caused by interfractional anatomical changes in prostate cancer.

  14. SU-E-J-254: Utility of Pinnacle Dynamic Planning Module Utilizing Deformable Image Registration in Adaptive Radiotherapy

    SciTech Connect

    Jani, S

    2014-06-01

    Purpose For certain highly conformal treatment techniques, changes in patient anatomy due to weight loss and/or tumor shrinkage can result in significant changes in dose distribution. Recently, the Pinnacle treatment planning system added a Dynamic Planning module utilizing Deformable Image Registration (DIR). The objective of this study was to evaluate the effectiveness of this software in adapting to altered anatomy and adjusting treatment plans to account for it. Methods We simulated significant tumor response by changing patient thickness and altered chin positions using a commercially-available head and neck (H and N) phantom. In addition, we studied 23 CT image sets of fifteen (15) patients with H and N tumors and eight (8) patients with prostate cancer. In each case, we applied deformable image registration through Dynamic Planning module of our Pinnacle Treatment Planning System. The dose distribution of the original CT image set was compared to the newly computed dose without altering any treatment parameter. Result was a dose if we did not adjust the plan to reflect anatomical changes. Results For the H and N phantom, a tumor response of up to 3.5 cm was correctly deformed by the Pinnacle Dynamic module. Recomputed isodose contours on new anatomies were within 1 mm of the expected distribution. The Pinnacle system configuration allowed dose computations resulting from original plans on new anatomies without leaving the planning system. Original and new doses were available side-by-side with both CT image sets. Based on DIR, about 75% of H and N patients (11/15) required a re-plan using new anatomy. Among prostate patients, the DIR predicted near-correct bladder volume in 62% of the patients (5/8). Conclusions The Dynamic Planning module of the Pinnacle system proved to be an accurate and useful tool in our ability to adapt to changes in patient anatomy during a course of radiotherapy.

  15. Lessons from the construction of a climate change adaptation plan: A Broads wetland case study.

    PubMed

    Turner, R Kerry; Palmieri, Maria Giovanna; Luisetti, Tiziana

    2016-10-01

    The dynamic nature of environmental change in coastal areas means that a flexible "learning by doing" management strategy has a number of advantages. This article lays out the principles of such a strategy and then assesses an actual planning and management process focused on climate change consequences for the Broads wetland on the East coast of England. The management strategy focused on the concept of ecosystem services (stocks and flows) provided by the coastal wetland and the threats and opportunities posed to the area by sea level rise and other climate change impacts. The analysis explores the process by which an adaptive management plan has been formulated and coproduced by a combination of centralized (vertical) and stakeholder social network (horizontal) arrangements. The process values where feasible the ecosystem services under threat and prioritizes response actions. Coastal management needs a careful balance between strategic requirements imposed at a national scale and local schemes that affect regional and/or local communities and social networks. These networks aided by electronic media have allowed groups to engage more rapidly and effectively with policy proposals. However, successful deliberation is conditioned by a range of context specific factors, including the type of social networks present and their relative competitive and/or complementary characteristics. The history of consultation and dialogue between official agencies and stakeholders also plays a part in contemporary deliberation processes and the success of their outcomes. Among the issues highlighted are the multiple dimensions of nature's value; the difficulty of quantifying some ecosystem service changes, especially for cultural services; and the problem of "stakeholder fatigue" complicating engagement arrangements. Integr Environ Assess Manag 2016;12:719-725. © 2016 SETAC.

  16. Lessons from the construction of a climate change adaptation plan: A Broads wetland case study.

    PubMed

    Turner, R Kerry; Palmieri, Maria Giovanna; Luisetti, Tiziana

    2016-10-01

    The dynamic nature of environmental change in coastal areas means that a flexible "learning by doing" management strategy has a number of advantages. This article lays out the principles of such a strategy and then assesses an actual planning and management process focused on climate change consequences for the Broads wetland on the East coast of England. The management strategy focused on the concept of ecosystem services (stocks and flows) provided by the coastal wetland and the threats and opportunities posed to the area by sea level rise and other climate change impacts. The analysis explores the process by which an adaptive management plan has been formulated and coproduced by a combination of centralized (vertical) and stakeholder social network (horizontal) arrangements. The process values where feasible the ecosystem services under threat and prioritizes response actions. Coastal management needs a careful balance between strategic requirements imposed at a national scale and local schemes that affect regional and/or local communities and social networks. These networks aided by electronic media have allowed groups to engage more rapidly and effectively with policy proposals. However, successful deliberation is conditioned by a range of context specific factors, including the type of social networks present and their relative competitive and/or complementary characteristics. The history of consultation and dialogue between official agencies and stakeholders also plays a part in contemporary deliberation processes and the success of their outcomes. Among the issues highlighted are the multiple dimensions of nature's value; the difficulty of quantifying some ecosystem service changes, especially for cultural services; and the problem of "stakeholder fatigue" complicating engagement arrangements. Integr Environ Assess Manag 2016;12:719-725. © 2016 SETAC. PMID:26946335

  17. NOTE: Implementation of biologically conformal radiation therapy (BCRT) in an algorithmic segmentation-based inverse planning approach

    NASA Astrophysics Data System (ADS)

    Vanderstraeten, Barbara; DeGersem, Werner; Duthoy, Wim; DeNeve, Wilfried; Thierens, Hubert

    2006-08-01

    The development of new biological imaging technologies offers the opportunity to further individualize radiotherapy. Biologically conformal radiation therapy (BCRT) implies the use of the spatial distribution of one or more radiobiological parameters to guide the IMRT dose prescription. Our aim was to implement BCRT in an algorithmic segmentation-based planning approach. A biology-based segmentation tool was developed to generate initial beam segments that reflect the biological signal intensity pattern. The weights and shapes of the initial segments are optimized by means of an objective function that minimizes the root mean square deviation between the actual and intended dose values within the PTV. As proof of principle, [18F]FDG-PET-guided BCRT plans for two different levels of dose escalation were created for an oropharyngeal cancer patient. Both plans proved to be dosimetrically feasible without violating the planning constraints for the expanded spinal cord and the contralateral parotid gland as organs at risk. The obtained biological conformity was better for the first (2.5 Gy per fraction) than for the second (3 Gy per fraction) dose escalation level.

  18. A health impact assessment framework for assessing vulnerability and adaptation planning for climate change.

    PubMed

    Brown, Helen; Spickett, Jeffery; Katscherian, Dianne

    2014-12-12

    This paper presents a detailed description of an approach designed to investigate the application of the Health Impact Assessment (HIA) framework to assess the potential health impacts of climate change. A HIA framework has been combined with key climate change terminology and concepts. The fundamental premise of this framework is an understanding of the interactions between people, the environment and climate. The diversity and complexity of these interactions can hinder much needed action on the critical health issue of climate change. The objectives of the framework are to improve the methodology for understanding and assessing the risks associated with potential health impacts of climate change, and to provide decision-makers with information that can facilitate the development of effective adaptation plans. While the process presented here provides guidance with respect to this task it is not intended to be prescriptive. As such, aspects of the process can be amended to suit the scope and available resources of each project. A series of working tables has been developed to assist in the collation of evidence throughout the process. The framework has been tested in a number of locations including Western Australia, Solomon Islands, Vanuatu and Nauru.

  19. A Health Impact Assessment Framework for Assessing Vulnerability and Adaptation Planning for Climate Change

    PubMed Central

    Brown, Helen; Spickett, Jeffery; Katscherian, Dianne

    2014-01-01

    This paper presents a detailed description of an approach designed to investigate the application of the Health Impact Assessment (HIA) framework to assess the potential health impacts of climate change. A HIA framework has been combined with key climate change terminology and concepts. The fundamental premise of this framework is an understanding of the interactions between people, the environment and climate. The diversity and complexity of these interactions can hinder much needed action on the critical health issue of climate change. The objectives of the framework are to improve the methodology for understanding and assessing the risks associated with potential health impacts of climate change, and to provide decision-makers with information that can facilitate the development of effective adaptation plans. While the process presented here provides guidance with respect to this task it is not intended to be prescriptive. As such, aspects of the process can be amended to suit the scope and available resources of each project. A series of working tables has been developed to assist in the collation of evidence throughout the process. The framework has been tested in a number of locations including Western Australia, Solomon Islands, Vanuatu and Nauru. PMID:25514146

  20. Adaptation Strategies to Climate Change and the Role of Planning Instruments - The Example of the Dresden Region (Saxony/Germany)

    NASA Astrophysics Data System (ADS)

    Albrecht, J.; Juta, K.; Nobis, A.

    2009-04-01

    In the past, identifying anthropogenic influences on climate change, scenario analyses and issues of climate change mitigation were predominant approaches in climate change research (IPCC 2007). Currently, for instance in Germany, climate impact research on regional level comes to the forefront of research and policy making. Climate change has become an important topic on the agenda of politicians, administration and planning. In order to counteract the (unavoidable) climate change and its impacts it is necessary to develop adaptation strategies. At present, such strategies and guidelines are formulated on international, supranational and national level. The initial point was the United Nations Framework Convention on Climate Change in 1992 where the contracting states obligated themselves to develop national (and regional) programmes for adaptation. In 2007 the European Commission published its Green Paper called Adaptation to Climate Change in Europe. The paper states that adaptation efforts have to be intensified at different (spatial) levels (local, regional, national, and so forth). Furthermore, coordinating these efforts is of high importance. With the recent agreement on the German Adaptation Strategy to Climate Change (DAS 2008) in December 2008, federal government tries to accomplish this task. The German strategy mainly focuses on two elements: decreasing vulnerability and increasing adaptability. While the above mentioned strategies have presented information and policies concerning climate change and adaptation on international, supranational and national level, such documents dońt yet exist on regional level. However, because of their close link to the local level the regions are of high importance for adaptation strategies. Therefore, the Leibniz-Institute of Ecological and Regional Development developed a transdisciplinary project to formulate and implement the so-called Integrated Regional Climate Adaptation Programme (IRCAP) for the Model Region

  1. Towards automated on-line adaptation of 2-Step IMRT plans: QUASIMODO phantom and prostate cancer cases

    PubMed Central

    2013-01-01

    Background The standard clinical protocol of image-guided IMRT for prostate carcinoma introduces isocenter relocation to restore the conformity of the multi-leaf collimator (MLC) segments to the target as seen in the cone-beam CT on the day of treatment. The large interfractional deformations of the clinical target volume (CTV) still require introduction of safety margins which leads to undesirably high rectum toxicity. Here we present further results from the 2-Step IMRT method which generates adaptable prostate IMRT plans using Beam Eye View (BEV) and 3D information. Methods Intermediate/high-risk prostate carcinoma cases are treated using Simultaneous Integrated Boost at the Universitätsklinkum Würzburg (UKW). Based on the planning CT a CTV is defined as the prostate and the base of seminal vesicles. The CTV is expanded by 10 mm resulting in the PTV; the posterior margin is limited to 7 mm. The Boost is obtained by expanding the CTV by 5 mm, overlap with rectum is not allowed. Prescription doses to PTV and Boost are 60.1 and 74 Gy respectively given in 33 fractions. We analyse the geometry of the structures of interest (SOIs): PTV, Boost, and rectum, and generate 2-Step IMRT plans to deliver three fluence steps: conformal to the target SOIs (S0), sparing the rectum (S1), and narrow segments compensating the underdosage in the target SOIs due to the rectum sparing (S2). The width of S2 segments is calculated for every MLC leaf pair based on the target and rectum geometry in the corresponding CT layer to have best target coverage. The resulting segments are then fed into the DMPO optimizer of the Pinnacle treatment planning system for weight optimization and fine-tuning of the form, prior to final dose calculation using the collapsed cone algorithm. We adapt 2-Step IMRT plans to changed geometry whilst simultaneously preserving the number of initially planned Monitor Units (MU). The adaptation adds three further steps to the previous isocenter relocation: 1

  2. Using Rapid-Response Scenario-Building Methodology for Climate Change Adaptation Planning

    NASA Astrophysics Data System (ADS)

    Ludwig, K. A.; Stoepler, T. M.; Schuster, R.

    2015-12-01

    Rapid-response scenario-building methodology can be modified to develop scenarios for slow-onset disasters associated with climate change such as drought. Results of a collaboration between the Department of the Interior (DOI) Strategic Sciences Group (SSG) and the Southwest Colorado Social-Ecological Climate Resilience Project are presented in which SSG scenario-building methods were revised and applied to climate change adaptation planning in Colorado's Gunnison Basin, United States. The SSG provides the DOI with the capacity to rapidly assemble multidisciplinary teams of experts to develop scenarios of the potential environmental, social, and economic cascading consequences of environmental crises, and to analyze these chains to determine actionable intervention points. By design, the SSG responds to acute events of a relatively defined duration. As a capacity-building exercise, the SSG explored how its scenario-building methodology could be applied to outlining the cascading consequences of slow-onset events related to climate change. SSG staff facilitated two workshops to analyze the impacts of drought, wildfire, and insect outbreak in the sagebrush and spruce-fir ecosystems. Participants included local land managers, natural and social scientists, ranchers, and other stakeholders. Key findings were: 1) scenario framing must be adjusted to accommodate the multiple, synergistic components and longer time frames of slow-onset events; 2) the development of slow-onset event scenarios is likely influenced by participants having had more time to consider potential consequences, relative to acute events; 3) participants who are from the affected area may have a more vested interest in the outcome and/or may be able to directly implement interventions.

  3. Motion Analysis of 100 Mediastinal Lymph Nodes: Potential Pitfalls in Treatment Planning and Adaptive Strategies

    SciTech Connect

    Pantarotto, Jason R.; Piet, Anna H.M.; Vincent, Andrew; Soernsen de Koste, John R. van; Senan, Suresh

    2009-07-15

    Purpose: The motion of mediastinal lymph nodes may undermine local control with involved-field radiotherapy. We studied patterns of nodal and tumor motion in 41 patients with lung cancer. Methods and Materials: Four-dimensional (4D) computed tomography planning scans were retrospectively evaluated to identify patients with clearly visible mediastinal lymph nodes. One hundred nodes from 14 patients with Stage I and 27 patients with Stage III were manually contoured in all 4D computed tomography respiratory phases. Motion was derived from changes in the nodal center-of-mass position. Primary tumors were also delineated in all phases for 16 patients with Stage III disease. Statistical analysis included a multivariate mixed-effects model of grouped data. Results: Average 3D nodal motion during quiet breathing was 0.68 cm (range, 0.17-1.64 cm); 77% moved greater than 0.5 cm, and 10% moved greater than 1.0 cm. Motion was greatest in the lower mediastinum (p = 0.002), and nodes measuring 2 cm or greater in diameter showed motion similar to that in smaller nodes. In 11 of 16 patients studied, at least one node moved more than the corresponding primary tumor. No association between 3D primary tumor motion and nodal motion was observed. For mobile primary tumors, phase offsets between the primary tumor and nodes of two or more and three or more phases were observed for 33% and 12% of nodes, respectively. Conclusions: Mediastinal nodal motion is common, with phase offsets seen between the primary tumor and different nodes in the same patient. Patient-specific information is needed to ensure geometric coverage, and adaptive strategies based solely on the primary tumor may be misleading.

  4. Adaptive Planning in Intensity-Modulated Radiation Therapy for Head and Neck Cancers: Single-Institution Experience and Clinical Implications

    SciTech Connect

    Ahn, Peter H.; Chen, Chin-Cheng; Ahn, Andrew I.; Hong, Linda; Scripes, Paola G.; Shen Jin; Lee, Chen-Chiao; Miller, Ekeni; Kalnicki, Shalom; Garg, Madhur K.

    2011-07-01

    Purpose: Anatomic changes and positional variability during intensity-modulated radiation therapy (IMRT) for head and neck cancer can lead to clinically significant dosimetric changes. We report our single-institution experience using an adaptive protocol and correlate these changes with anatomic and positional changes during treatment. Methods and Materials: Twenty-three sequential head and neck IMRT patients underwent serial computed tomography (CT) scans during their radiation course. After undergoing the planning CT scan, patients underwent planned rescans at 11, 22, and 33 fractions; a total of 89 scans with 129 unique CT plan combinations were thus analyzed. Positional variability and anatomic changes during treatment were correlated with changes in dosimetric parameters to target and avoidance structures between planning CT and subsequent scans. Results: A total of 15/23 patients (65%) benefited from adaptive planning, either due to inadequate dose to gross disease or to increased dose to organs at risk. Significant differences in primary and nodal targets (planning target volume, gross tumor volume, and clinical tumor volume), parotid, and spinal cord dosimetric parameters were noted throughout the treatment. Correlations were established between these dosimetric changes and weight loss, fraction number, multiple skin separations, and change in position of the skull, mandible, and cervical spine. Conclusions: Variations in patient positioning and anatomy changes during IMRT for head and neck cancer can affect dosimetric parameters and have wide-ranging clinical implications. The interplay between random positional variability and gradual anatomic changes requires careful clinical monitoring and frequent use of CT- based image-guided radiation therapy, which should determine variations necessitating new plans.

  5. Summarizing components of U.S. Department of the Interior vulnerability assessments to focus climate adaptation planning

    USGS Publications Warehouse

    Thompson, Laura M.; Staudinger, Michelle D.; Carter, Shawn L.

    2015-09-29

    A secretarial order identified climate adaptation as a critical performance objective for future management of U.S. Department of the Interior (DOI) lands and resources in response to global change. Vulnerability assessments can inform climate adaptation planning by providing insight into what natural resources are most at risk and why. Three components of vulnerability—exposure, sensitivity, and adaptive capacity—were defined by the Intergovernmental Panel on Climate Change (IPCC) as necessary for identifying climate adaptation strategies and actions. In 2011, the DOI requested all internal bureaus report ongoing or completed vulnerability assessments about a defined range of assessment targets or climate-related threats. Assessment targets were defined as freshwater resources, landscapes and wildlife habitat, native and cultural resources, and ocean health. Climate-related threats were defined as invasive species, wildfire risk, sea-level rise, and melting ice and permafrost. Four hundred and three projects were reported, but the original DOI survey did not specify that information be provided on exposure, sensitivity, and adaptive capacity collectively as part of the request, and it was unclear which projects adhered to the framework recommended by the IPCC. Therefore, the U.S. Geological Survey National Climate Change and Wildlife Science Center conducted a supplemental survey to determine how frequently each of the three vulnerability components was assessed. Information was categorized for 124 of the 403 reported projects (30.8 percent) based on the three vulnerability components, and it was discovered that exposure was the most common component assessed (87.9 percent), followed by sensitivity (68.5 percent) and adaptive capacity (33.1 percent). The majority of projects did not fully assess vulnerability; projects focused on landscapes/wildlife habitats and sea-level rise were among the minority that simultaneously addressed all three vulnerability

  6. Summarizing components of U.S. Department of the Interior vulnerability assessments to focus climate adaptation planning

    USGS Publications Warehouse

    Thompson, Laura M.; Staudinger, Michelle D.; Carter, Shawn L.

    2015-01-01

    A secretarial order identified climate adaptation as a critical performance objective for future management of U.S. Department of the Interior (DOI) lands and resources in response to global change. Vulnerability assessments can inform climate adaptation planning by providing insight into what natural resources are most at risk and why. Three components of vulnerability—exposure, sensitivity, and adaptive capacity—were defined by the Intergovernmental Panel on Climate Change (IPCC) as necessary for identifying climate adaptation strategies and actions. In 2011, the DOI requested all internal bureaus report ongoing or completed vulnerability assessments about a defined range of assessment targets or climate-related threats. Assessment targets were defined as freshwater resources, landscapes and wildlife habitat, native and cultural resources, and ocean health. Climate-related threats were defined as invasive species, wildfire risk, sea-level rise, and melting ice and permafrost. Four hundred and three projects were reported, but the original DOI survey did not specify that information be provided on exposure, sensitivity, and adaptive capacity collectively as part of the request, and it was unclear which projects adhered to the framework recommended by the IPCC. Therefore, the U.S. Geological Survey National Climate Change and Wildlife Science Center conducted a supplemental survey to determine how frequently each of the three vulnerability components was assessed. Information was categorized for 124 of the 403 reported projects (30.8 percent) based on the three vulnerability components, and it was discovered that exposure was the most common component assessed (87.9 percent), followed by sensitivity (68.5 percent) and adaptive capacity (33.1 percent). The majority of projects did not fully assess vulnerability; projects focused on landscapes/wildlife habitats and sea-level rise were among the minority that simultaneously addressed all three vulnerability

  7. Missouri River Emergent Sandbar Habitat Monitoring Plan - A Conceptual Framework for Adaptive Management

    USGS Publications Warehouse

    Sherfy, Mark H.; Stucker, Jennifer H.; Anteau, Michael J.

    2009-01-01

    available to quantify changes in managed habitats for least terns and piping plovers, so that management effectiveness can be evaluated. Extremely high flows and flooding of the Missouri River in 1997 created and improved vast amounts of nesting habitat for least terns and piping plovers. Since 1998, there has been an apparent loss and/or degradation of habitat throughout the river system. However, during the same timeframe reservoir water levels have declined, exposing extensive piping plover breeding habitat. For example, 64 percent of adult piping plovers using the Missouri River in 2005 were observed on reservoir habitats, and 43 percent were observed on Lake Sakakawea (Threatened and Endangered Species Section, Omaha District, U.S. Army Corps of Engineers, unpub. data, 2006). Given the vast dynamics of this river and reservoir system, systemwide monitoring of habitat is clearly needed for the U.S. Army Corps of Engineers (USACE) to employ adaptive management (with respect to river operations) to provide most optimal conditions for the maintenance of breeding habitat of least terns and piping plovers. As a result of this need, the U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers, began work on a habitat monitoring plan in 2005 as a conceptual framework for adaptive management.

  8. Back to the Future -Precipitation Extremes, Climate Variability, Environmental Planning and Adaptation

    NASA Astrophysics Data System (ADS)

    Barros, A. P.

    2008-12-01

    uncertainty and separating climatic variability and change from model error. Nonstationarity and persistence at multiple scales confound the problem. From an economics perspective, the unprecedented success of environmental control and "conservation" in the 20th century, present another yet challenge in terms of social expectations and human development, including the right to sustainable (high) quality of life. In this presentation, we illustrate these challenges by considering first the estimation of Probable Maximum Precipitation, an engineering design criterion typically used in dam design, and examine how it varies spatially across the continental US according to physiographic region and as a function of climate regime. Second, we explore the spatial and temporal scales that link climate variability to macroscale environmental planning, and the notion of place-based adaptive riskgrade analysis.

  9. A Review of National-Level Adaptation Planning with Regards to the Risks Posed by Climate Change on Infectious Diseases in 14 OECD Nations

    PubMed Central

    Panic, Mirna; Ford, James D.

    2013-01-01

    Climate change is likely to have significant implications for human health, particularly through alterations of the incidence, prevalence, and distribution of infectious diseases. In the context of these risks, governments in high income nations have begun developing strategies to reduce potential climate change impacts and increase health system resilience (i.e., adaptation). In this paper, we review and evaluate national-level adaptation planning in relation to infectious disease risks in 14 OECD countries with respect to “best practices” for adaptation identified in peer-reviewed literature. We find a number of limitations to current planning, including negligible consideration of the needs of vulnerable population groups, limited emphasis on local risks, and inadequate attention to implementation logistics, such as available funding and timelines for evaluation. The nature of planning documents varies widely between nations, four of which currently lack adaptation plans. In those countries where planning documents were available, adaptations were mainstreamed into existing public health programs, and prioritized a sectoral, rather than multidisciplinary, approach. The findings are consistent with other scholarship examining adaptation planning indicating an ad hoc and fragmented process, and support the need for enhanced attention to adaptation to infectious disease risks in public health policy at a national level. PMID:24351735

  10. Inversion layer MOS solar cells

    NASA Technical Reports Server (NTRS)

    Ho, Fat Duen

    1986-01-01

    Inversion layer (IL) Metal Oxide Semiconductor (MOS) solar cells were fabricated. The fabrication technique and problems are discussed. A plan for modeling IL cells is presented. Future work in this area is addressed.

  11. Adaptive/Nonadaptive Proton Radiation Planning and Outcomes in a Phase II Trial for Locally Advanced Non-small Cell Lung Cancer

    SciTech Connect

    Koay, Eugene J.; Lege, David; Mohan, Radhe; Komaki, Ritsuko; Cox, James D.; Chang, Joe Y.

    2012-12-01

    Purpose: To analyze dosimetric variables and outcomes after adaptive replanning of radiation therapy during concurrent high-dose protons and chemotherapy for locally advanced non-small cell lung cancer (NSCLC). Methods and Materials: Nine of 44 patients with stage III NSCLC in a prospective phase II trial of concurrent paclitaxel/carboplatin with proton radiation [74 Gy(RBE) in 37 fractions] had modifications to their original treatment plans after re-evaluation revealed changes that would compromise coverage of the target volume or violate dose constraints; plans for the other 35 patients were not changed. We compared patients with adaptive plans with those with nonadaptive plans in terms of dosimetry and outcomes. Results: At a median follow-up of 21.2 months (median overall survival, 29.6 months), no differences were found in local, regional, or distant failure or overall survival between groups. Adaptive planning was used more often for large tumors that shrank to a greater extent (median, 107.1 cm{sup 3} adaptive and 86.4 cm{sup 3} nonadaptive; median changes in volume, 25.3% adaptive and 1.2% nonadaptive; P<.01). The median number of fractions delivered using adaptive planning was 13 (range, 4-22). Adaptive planning generally improved sparing of the esophagus (median absolute decrease in V{sub 70}, 1.8%; range, 0%-22.9%) and spinal cord (median absolute change in maximum dose, 3.7 Gy; range, 0-13.8 Gy). Without adaptive replanning, target coverage would have been compromised in 2 cases (57% and 82% coverage without adaptation vs 100% for both with adaptation); neither patient experienced local failure. Radiation-related grade 3 toxicity rates were similar between groups. Conclusions: Adaptive planning can reduce normal tissue doses and prevent target misses, particularly for patients with large tumors that shrink substantially during therapy. Adaptive plans seem to have acceptable toxicity and achieve similar local, regional, and distant control and overall

  12. On-line re-optimization of prostate IMRT plan for adaptive radiation therapy: A feasibility study and implementation

    NASA Astrophysics Data System (ADS)

    Thongphiew, Danthai

    Prostate cancer is a disease that affected approximately 200,000 men in United States in 2006. Radiation therapy is a non invasive treatment option for this disease and is highly effective. The goal of radiation therapy is to deliver the prescription dose to the tumor (prostate) while sparing the surrounding healthy organs (e.g. bladder, rectum, and femoral heads). One limitation of the radiation therapy is organ position and shape variation from day to day. These variations could be as large as half inch. The conventional solution to this problem is to include some margins surrounding the target when plan the treatment. The development of image guided radiation therapy technique allows in-room correction which potentially eliminates the patient setup error however the uncertainty due to organ deformation still remains. Performing a plan re-optimization will take about half hour which is infeasible to perform an online correction. A technique of performing online re-optimization of intensity modulated radiation therapy is developed for adaptive radiation therapy of prostate cancer. The technique is capable of correction both organ positioning and shape changes within a few minutes. The proposed technique involves (1) 3D on-board imaging of daily anatomy, (2) registering the daily images with original planning CT images and mapping the original dose distribution to the daily anatomy, (3) real time re-optimization of the plan. Finally the leaf sequences are calculated for the treatment delivery. The feasibility of this online adaptive radiation therapy scheme was evaluated by clinical cases. The results demonstrate that it is feasible to perform online re-optimization of the original plan when large position or shape variation occurs.

  13. Designing and Adapting Tasks in Lesson Planning: A Critical Process of Lesson Study

    ERIC Educational Resources Information Center

    Fujii, Toshiakira

    2016-01-01

    There is no doubt that a lesson plan is a necessary product of Lesson Study. However, the collaborative work among teachers that goes into creating that lesson plan is largely under-appreciated by non-Japanese adopters of Lesson Study, possibly because the effort involved is invisible to outsiders, with our attention going to its most visible…

  14. SU-E-J-68: Adaptive Radiotherapy of Head and Neck Cancer: Re-Planning Based On Prior Dose

    SciTech Connect

    Dogan, N; Padgett, K; Evans, J; Sleeman, W; Song, S; Fatyga, M

    2015-06-15

    Purpose: Adaptive Radiotherapy (ART) with frequent CT imaging has been used to improve dosimetric accuracy by accounting for anatomical variations, such as primary tumor shrinkage and/or body weight loss, in Head and Neck (H&N) patients. In most ART strategies, the difference between the planned and the delivered dose is estimated by generating new plans on repeated CT scans using dose-volume constraints used with the initial planning CT without considering already delivered dose. The aim of this study was to assess the dosimetric gains achieved by re-planning based on prior dose by comparing them to re-planning not based-on prior dose for H&N patients. Methods: Ten locally-advanced H&N cancer patients were selected for this study. For each patient, six weekly CT imaging were acquired during the course of radiotherapy. PTVs, parotids, cord, brainstem, and esophagus were contoured on both planning and six weekly CT images. ART with weekly re-plans were done by two strategies: 1) Generating a new optimized IMRT plan without including prior dose from previous fractions (NoPriorDose) and 2) Generating a new optimized IMRT plan based on the prior dose given from previous fractions (PriorDose). Deformable image registration was used to accumulate the dose distributions between planning and six weekly CT scans. The differences in accumulated doses for both strategies were evaluated using the DVH constraints for all structures. Results: On average, the differences in accumulated doses for PTV1, PTV2 and PTV3 for NoPriorDose and PriorDose strategies were <2%. The differences in Dmean to the cord and brainstem were within 3%. The esophagus Dmean was reduced by 2% using PriorDose. PriorDose strategy, however, reduced the left parotid D50 and Dmean by 15% and 14% respectively. Conclusion: This study demonstrated significant parotid sparing, potentially reducing xerostomia, by using ART with IMRT optimization based on prior dose for weekly re-planning of H&N cancer patients.

  15. Local heat stroke prevention plans in Japan: characteristics and elements for public health adaptation to climate change.

    PubMed

    Martinez, Gerardo Sanchez; Imai, Chisato; Masumo, Kanako

    2011-12-01

    The adverse health effects from hot weather and heat waves represent significant public health risks in vulnerable areas worldwide. Rising temperatures due to climate change are aggravating these risks in a context of fast urbanization, population growth and societal ageing. However, environmental heat-related health effects are largely preventable through adequate preparedness and responses. Public health adaptation to climate change will often require the implementation of heat wave warning systems and targeted preventive activities at different levels. While several national governments have established such systems at the country level, municipalities do not generally play a major role in the prevention of heat disorders. This paper analyzes selected examples of locally operated heat-health prevention plans in Japan. The analysis of these plans highlights their strengths, but also the need of local institutions for assistance to make the transition towards an effective public health management of high temperatures and heat waves. It can also provide useful elements for municipal governments in vulnerable areas, both in planning their climate change and health adaptation activities or to better protect their communities against current health effects from heat.

  16. Local Heat Stroke Prevention Plans in Japan: Characteristics and Elements for Public Health Adaptation to Climate Change

    PubMed Central

    Martinez, Gerardo Sanchez; Imai, Chisato; Masumo, Kanako

    2011-01-01

    The adverse health effects from hot weather and heat waves represent significant public health risks in vulnerable areas worldwide. Rising temperatures due to climate change are aggravating these risks in a context of fast urbanization, population growth and societal ageing. However, environmental heat-related health effects are largely preventable through adequate preparedness and responses. Public health adaptation to climate change will often require the implementation of heat wave warning systems and targeted preventive activities at different levels. While several national governments have established such systems at the country level, municipalities do not generally play a major role in the prevention of heat disorders. This paper analyzes selected examples of locally operated heat-health prevention plans in Japan. The analysis of these plans highlights their strengths, but also the need of local institutions for assistance to make the transition towards an effective public health management of high temperatures and heat waves. It can also provide useful elements for municipal governments in vulnerable areas, both in planning their climate change and health adaptation activities or to better protect their communities against current health effects from heat. PMID:22408589

  17. Adaptive Liver Stereotactic Body Radiation Therapy: Automated Daily Plan Reoptimization Prevents Dose Delivery Degradation Caused by Anatomy Deformations

    SciTech Connect

    Leinders, Suzanne M.; Breedveld, Sebastiaan; Méndez Romero, Alejandra; Schaart, Dennis; Seppenwoolde, Yvette; Heijmen, Ben J.M.

    2013-12-01

    Purpose: To investigate how dose distributions for liver stereotactic body radiation therapy (SBRT) can be improved by using automated, daily plan reoptimization to account for anatomy deformations, compared with setup corrections only. Methods and Materials: For 12 tumors, 3 strategies for dose delivery were simulated. In the first strategy, computed tomography scans made before each treatment fraction were used only for patient repositioning before dose delivery for correction of detected tumor setup errors. In adaptive second and third strategies, in addition to the isocenter shift, intensity modulated radiation therapy beam profiles were reoptimized or both intensity profiles and beam orientations were reoptimized, respectively. All optimizations were performed with a recently published algorithm for automated, multicriteria optimization of both beam profiles and beam angles. Results: In 6 of 12 cases, violations of organs at risk (ie, heart, stomach, kidney) constraints of 1 to 6 Gy in single fractions occurred in cases of tumor repositioning only. By using the adaptive strategies, these could be avoided (<1 Gy). For 1 case, this needed adaptation by slightly underdosing the planning target volume. For 2 cases with restricted tumor dose in the planning phase to avoid organ-at-risk constraint violations, fraction doses could be increased by 1 and 2 Gy because of more favorable anatomy. Daily reoptimization of both beam profiles and beam angles (third strategy) performed slightly better than reoptimization of profiles only, but the latter required only a few minutes of computation time, whereas full reoptimization took several hours. Conclusions: This simulation study demonstrated that replanning based on daily acquired computed tomography scans can improve liver stereotactic body radiation therapy dose delivery.

  18. Science-society collaboration for robust adaptation planning in water management - The Maipo River Basin in Chile

    NASA Astrophysics Data System (ADS)

    Ocampo Melgar, Anahí; Vicuña, Sebastián; Gironás, Jorge

    2015-04-01

    The Metropolitan Region (M.R.) in Chile is populated by over 6 million people and supplied by the Maipo River and its large number of irrigation channels. Potential environmental alterations caused by global change will extremely affect managers and users of water resources in this semi-arid basin. These hydro-climatological impacts combined with demographic and economic changes will be particularly complex in the city of Santiago, due to the diverse, counterpoised and equally important existing activities and demands. These challenges and complexities request the implementation of flexible plans and actions to adapt policies, institutions, infrastructure and behaviors to a new future with climate change. Due to the inherent uncertainties in the future, a recent research project entitled MAPA (Maipo Adaptation Plan for its initials in Spanish) has formed a collaborative science-society platform to generate insights into the vulnerabilities, challenges and possible mitigation measures that would be necessary to deal with the potential changes in the M.R. This large stakeholder platform conformed by around 30 public, private and civil society organizations, both at the local and regional level and guided by a Robust Decision Making Framework (RDMF) has identified vulnerabilities, future scenarios, performance indicators and mitigation measures for the Maipo River basin. The RDMF used in this project is the XLRM framework (Lempert et al. 2006) that incorporates policy levers (L), exogenous uncertainties (X), measures of performance standards (M) and relationships (R) in an interlinked process. Both stakeholders' expertise and computational capabilities have been used to create hydrological models for the urban, rural and highland sectors supported also by the Water Evaluation and Planning system software (WEAP). The identification of uncertainties and land use transition trends was used to develop future development scenarios to explore possible water management

  19. Toward Quantitative Analysis of Water-Energy-Urban-Climate Nexus for Urban Adaptation Planning

    EPA Science Inventory

    Water and energy are two interwoven factors affecting environmental management and urban development planning. Meanwhile, rapid urban development and a changing climate exacerbate the magnitude and effects of water-energy interactions in what nexus defines. These factors and th...

  20. Adapting and Testing Business Management Development Programs for Educational Administrators. Volume 5 of 6 Volumes. Appendix I-Planning Document: North Carolina LEA, Laurinburg-Scotland. Final Report.

    ERIC Educational Resources Information Center

    Klawuhn, Raymond E.; Basso, Alexander J.

    This document is comprised of an appendix that provides a portion of the materials utilized in the project to test the feasibility of adapting business management practices to educational institutions. Included is the educational planning process document for one of the eight participating management teams. The planning process document states the…

  1. Adapting and Testing Business Management Development Programs for Educational Administrators. Volume 4 of 6 Volumes. Appendix G-Planning Document: North Carolina SEA, Program Services. Appendix H-Planning Document: North Carolina LEA, Cabarrus County. Final Report.

    ERIC Educational Resources Information Center

    Klawuhn, Raymond E.; Basso, Alexander J.

    This document is comprised of two appendixes that provide a portion of the materials utilized in the project to test the feasibility of adapting business management practices to educational institutions. Included are the educational planning process documents for two of the eight participating management teams. Each planning process document…

  2. Adapting and Testing Business Management Development Programs for Educational Administrators. Volume 3 of 6 Volumes. Appendix E-Planning Document: Maryland LEA, Prince George's Co., Appendix F-Planning Document: North Carolina SEA, Executive Staff. Final Report.

    ERIC Educational Resources Information Center

    Klawuhn, Raymond E.; Basso, Alexander J.

    This document is comprised of two appendixes that provide a portion of the materials utilized in the project to test the feasibility of adapting business management practices to educational institutions. Included are the educational planning process documents for two of the eight participating management teams. Each planning process document…

  3. Trajectory Planning and Optimized Adaptive Control for a Class of Wheeled Inverted Pendulum Vehicle Models.

    PubMed

    Yang, Chenguang; Li, Zhijun; Li, Jing

    2013-02-01

    In this paper, we investigate optimized adaptive control and trajectory generation for a class of wheeled inverted pendulum (WIP) models of vehicle systems. Aiming at shaping the controlled vehicle dynamics to be of minimized motion tracking errors as well as angular accelerations, we employ the linear quadratic regulation optimization technique to obtain an optimal reference model. Adaptive control has then been developed using variable structure method to ensure the reference model to be exactly matched in a finite-time horizon, even in the presence of various internal and external uncertainties. The minimized yaw and tilt angular accelerations help to enhance the vehicle rider's comfort. In addition, due to the underactuated mechanism of WIP, the vehicle forward velocity dynamics cannot be controlled separately from the pendulum tilt angle dynamics. Inspired by the control strategy of human drivers, who usually manipulate the tilt angle to control the forward velocity, we design a neural-network-based adaptive generator of implicit control trajectory (AGICT) of the tilt angle which indirectly "controls" the forward velocity such that it tracks the desired velocity asymptotically. The stability and optimal tracking performance have been rigorously established by theoretic analysis. In addition, simulation studies have been carried out to demonstrate the efficiency of the developed AGICT and optimized adaptive controller.

  4. Supporting Preservice Elementary Teachers' Critique and Adaptation of Science Lesson Plans Using Educative Curriculum Materials

    ERIC Educational Resources Information Center

    Beyer, Carrie; Davis, Elizabeth A.

    2009-01-01

    Critiquing and adapting curriculum materials are essential teaching practices but challenging for many preservice teachers. This study explores the use of educative curriculum materials--materials intended to support both teacher and student learning--to help preservice elementary teachers develop their pedagogical design capacity for critiquing…

  5. Adapting Online Learning Resources for All: Planning for Professionalism in Accessibility

    ERIC Educational Resources Information Center

    McAndrew, Patrick; Farrow, Robert; Cooper, Martyn

    2012-01-01

    Online resources for education offer opportunities for those with disabilities but also raise challenges on how to best adjust resources to accommodate accessibility. Automated reconfiguration could in principle remove the need for expensive and time-consuming discussions about adaptation. On the other hand, human-based systems provide much needed…

  6. Dosimetric and geometric evaluation of a hybrid strategy of offline adaptive planning and online image guidance for prostate cancer radiotherapy

    NASA Astrophysics Data System (ADS)

    Liu, Han; Wu, Qiuwen

    2011-08-01

    For prostate cancer patients, online image-guided (IG) radiotherapy has been widely used in clinic to correct the translational inter-fractional motion at each treatment fraction. For uncertainties that cannot be corrected online, such as rotation and deformation of the target volume, margins are still required to be added to the clinical target volume (CTV) for the treatment planning. Offline adaptive radiotherapy has been implemented to optimize the treatment for each individual patient based on the measurements at early stages of treatment process. It has been shown that offline adaptive radiotherapy can effectively reduce the required margin. Recently a hybrid strategy of offline adaptive replanning and online IG was proposed and the geometric evaluation was performed. It was found that the planning margins can further be reduced by 1-2 mm compared to online IG only strategy. The purpose of this study was to investigate the dosimetric benefits of such a hybrid strategy on the target and organs at risk. A total of 420 repeated helical computed tomography scans from 28 patients were included in the study. Both low-risk patients (LRP, CTV = prostate) and intermediate-risk patients (IRP, CTV = prostate + seminal vesicles, SV) were included in the simulation. Two registration methods, based on center-of-mass shift of prostate only and prostate plus SV, were performed for IRP. The intensity-modulated radiotherapy was used in the simulation. Criteria on both cumulative and fractional doses were evaluated. Furthermore, the geometric evaluation was extended to investigate the optimal number of fractions necessary to construct the internal target volume (ITV) for the hybrid strategy. The dosimetric margin improvement was smaller than its geometric counterpart and was in the range of 0-1 mm. The optimal number of fractions necessary for the ITV construction is 2 for LRPs and 3-4 for IRPs in a hypofractionation protocol. A new cumulative index of target volume was proposed

  7. Multi-optimization Criteria-based Robot Behavioral Adaptability and Motion Planning

    SciTech Connect

    Pin, Grancois G.

    2004-06-01

    Our overall objective is the development of a generalized methodology and code for the automated generation of the kinematics equations of robots and for the analytical solution of their motion planning equations subject to time-varying constraints, behavioral objectives, and modular configuration.

  8. Adaptation of Consultation Planning for Native American and Latina Women with Breast Cancer

    ERIC Educational Resources Information Center

    Belkora, Jeffrey; Franklin, Lauren; O'Donnell, Sara; Ohnemus, Julie; Stacey, Dawn

    2009-01-01

    Context: Resource centers in rural, underserved areas are implementing Consultation Planning (CP) to help women with breast cancer create a question list before a doctor visit. Purpose: To identify changes needed for acceptable delivery of CP to rural Native Americans and Latinas. Methods: We interviewed and surveyed 27 Native American and Latino…

  9. Health impacts of climate change in Vanuatu: an assessment and adaptation action plan.

    PubMed

    Spickett, Jeffery T; Katscherian, Dianne; McIver, Lachlan

    2013-01-30

    Climate change is one of the greatest global challenges and Pacific island countries are particularly vulnerable due to, among other factors, their geography, demography and level of economic development. A Health Impact Assessment (HIA) framework was used as a basis for the consideration of the potential health impacts of changes in the climate on the population of Vanuatu, to assess the risks and propose a range of potential adaptive responses appropriate for Vanuatu. The HIA process involved the participation of a broad range of stakeholders including expert sector representatives in the areas of bio-physical, socio-economic, infrastructure, environmental diseases and food, who provided informed comment and input into the understanding of the potential health impacts and development of adaptation strategies. The risk associated with each of these impacts was assessed with the application of a qualitative process that considered both the consequences and the likelihood of each of the potential health impacts occurring. Potential adaptation strategies and actions were developed which could be used to mitigate the identified health impacts and provide responses which could be used by the various sectors in Vanuatu to contribute to future decision making processes associated with the health impacts of climate change.

  10. A self-adaptive case-based reasoning system for dose planning in prostate cancer radiotherapy

    SciTech Connect

    Mishra, Nishikant; Petrovic, Sanja; Sundar, Santhanam

    2011-12-15

    Purpose: Prostate cancer is the most common cancer in the male population. Radiotherapy is often used in the treatment for prostate cancer. In radiotherapy treatment, the oncologist makes a trade-off between the risk and benefit of the radiation, i.e., the task is to deliver a high dose to the prostate cancer cells and minimize side effects of the treatment. The aim of our research is to develop a software system that will assist the oncologist in planning new treatments. Methods: A nonlinear case-based reasoning system is developed to capture the expertise and experience of oncologists in treating previous patients. Importance (weights) of different clinical parameters in the dose planning is determined by the oncologist based on their past experience, and is highly subjective. The weights are usually fixed in the system. In this research, the weights are updated automatically each time after generating a treatment plan for a new patient using a group based simulated annealing approach. Results: The developed approach is analyzed on the real data set collected from the Nottingham University Hospitals NHS Trust, City Hospital Campus, UK. Extensive experiments show that the dose plan suggested by the proposed method is coherent with the dose plan prescribed by an experienced oncologist or even better. Conclusions: The developed case-based reasoning system enables the use of knowledge and experience gained by the oncologist in treating new patients. This system may play a vital role to assist the oncologist in making a better decision in less computational time; it utilizes the success rate of the previously treated patients and it can also be used in teaching and training processes.

  11. MO-C-17A-06: Online Adaptive Re-Planning to Account for Independent Motions Between Multiple Targets During Radiotherapy of Lung Cancer

    SciTech Connect

    Liu, F; Tai, A; Ahunbay, E; Gore, E; Johnstone, C; Li, X

    2014-06-15

    Purpose: To quantify interfractional independent motions between multiple targets in radiotherapy (RT) of lung cancer, and to study the dosimetric benefits of an online adaptive replanning method to account for these variations. Methods: Ninety five diagnostic-quality daily CTs acquired for 9 lung cancer patients treated with IGRT using an in-room CT (CTVision, Siemens) were analyzed. On each daily CT set, contours of the targets (GTV, CTV, or involved nodes) and organs at risk were generated by populating the planning contours using an auto-segmentation tool (ABAS, Elekta) with manual editing. For each patient, an IMRT plan was generated based on the planning CT with a prescription dose of 60 Gy in 2Gy fractions. Three plans were generated and compared for each daily CT set: an IGRT (repositioning) plan by copying the original plan with the required shifts, an online adaptive plan by rapidly modifying the aperture shapes and segment weights of the original plan to conform to the daily anatomy, and a new fully re-optimized plan based on the daily CT using a planning system (Panther, Prowess). Results: The daily deviations of the distance between centers of masses of the targets from the plans varied daily from -10 to 8 mm with an average −0.9±4.1 mm (one standard deviation). The average CTV V100 are 99.0±0.7%, 97.9±2.8%, 99.0±0.6%, and 99.1±0.6%, and the lung V20 Gy 928±332 cc, 944±315 cc, 917±300 cc, and 891±295 cc for the original, repositioning, adaptive, and re-optimized plans, respectively. Wilcoxon signed-rank tests show that the adaptive plans are statistically significantly better than the repositioning plans and comparable with the reoptimized plans. Conclusion: There exist unpredictable, interfractional, relative volume changes and independent motions between multiple targets during lung cancer RT which cannot be accounted for by the current IGRT repositioning but can be corrected by the online adaptive replanning method.

  12. Adaptive Gait Control for a Quadruped Robot on 3D Path Planning

    NASA Astrophysics Data System (ADS)

    Igarashi, Hiroshi; Kakikura, Masayoshi

    A legged walking robot is able to not only move on irregular terrain but also change its posture. For example, the robot can pass under overhead obstacles by crouching. The purpose of our research is to realize efficient path planning with a quadruped robot. Therefore, the path planning is expected to extended in three dimensions because of the mobility. However, some issues of the quadruped robot, which are instability, workspace limitation, deadlock and slippage, complicate realizing such application. In order to improve these issues and reinforce the mobility, a new static gait pattern for a quadruped robot, called TFG: Trajectory Following Gait, is proposed. The TFG intends to obtain high controllability like a wheel robot. Additionally, the TFG allows to change it posture during the walk. In this paper, some experimental results show that the TFG improves the issues and it is available for efficient locomotion in three dimensional environment.

  13. Preparing for Future Water Resources Conflicts through Climate Change Adaptation Planning: A Case Study in Eastern Europe and Central Asia

    NASA Astrophysics Data System (ADS)

    Boehlert, B. B.; Neumann, J. E.; Strzepek, K.; Sutton, W.; Srivastava, J.

    2011-12-01

    Uncertainties posed by climate change and rapidly rising global water demand suggest that existing conflicts over water resources are likely to be exacerbated and new conflicts will appear where little or no conflict occurs today. Successfully planning for and preventing conflicts first requires a sound scientific understanding of the timing, location, and magnitude of water resource shortfalls, identification of the most appropriate climate adaptation options based on multiple criteria, and development of broad, multi-level consensus within the affected community. We recently applied this approach in a World Bank-funded adaptation assessment for the agricultural sectors of four countries in Eastern Europe and Central Asia-Albania, Macedonia, Moldova, and Uzbekistan. For each major basin, we first used a hydrological model to project changes in water availability through 2050 under country-specific high, medium, and low climate impact scenarios. Next, under the three climate scenarios, we projected changes in agricultural water demand using a crop model (i.e., AquaCrop and DSSAT), and changes in water demand in other sectors based on population projections and sectoral forecasts of changes in per capita use. We incorporated these water availability and demand projections-along with other characteristics of the water system such as water supply priorities, environmental and transboundary flow requirements, irrigation efficiency, and reservoir locations and volumes-into a monthly integrated water resource planning tool (the Water Evaluation And Planning tool, or WEAP) to generate projected unmet water demand under each climate scenario and to each sector through 2050. The findings suggest that the agricultural sector in each country (except the relatively water-rich Albania) would experience significant unmet water demands, up to 52 percent in the Syr Darya and Amu Darya River basins of Uzbekistan. Potential adaptation responses to address unmet water demands-such as

  14. Integrating Collaboration, Adaptive Management, and Scenario-Planning to Address Rapid Change: Experiences at Las Cienegas National Conservation Area

    NASA Astrophysics Data System (ADS)

    Caves, J. K.; Bodner, G.; Simms, K.; Fisher, L.; Robertson, T.

    2012-12-01

    There is growing recognition that public lands cannot be managed as islands; rather, land management must address the ecological, social, and temporal complexity that often spans jurisdictions and traditional planning horizons. Collaborative decision-making and adaptive management (CAM) have been promoted as methods to reconcile competing societal demands and respond to complex ecosystem dynamics. We present the experiences of land managers and stakeholders in using CAM at Las Cienegas National Conservation Area (LCNCA), a highly valued site under the jurisdiction of the Bureau of Land Management (BLM). The CAM process at Las Cienegas is marked by strong stakeholder engagement, with four core elements: 1) shared watershed goals with measurable resource objectives; 2) mechanisms to incorporate new information into decision-making; 3) efforts to make information increasingly relevant and reliable; and 4) shared learning to improve both the process and management actions. The combination of stakeholder engagement and adaptive management has led to agreement on contentious issues, more innovative solutions, and more effective land management. Yet the region is now experiencing rapid changes outside managers' control—including climate change, human population growth, and reduced federal budgets—with large but unpredictable impacts on natural resources. While CAM experience provides a strong foundation for making the difficult and contentious management decisions that such changes are likely to require, neither collaboration nor adaptive management provides a sufficient structure for addressing uncontrollable and unpredictable change. As a result, LCNCA is exploring two specific modifications to CAM that may better address emerging challenges, including: 1) Creating nested resource objectives to distinguish between those objectives which may be crucial from those which may hinder a flexible response to climate change, and 2) Incorporating scenario planning into CAM

  15. Adaptive planning strategy for high dose rate prostate brachytherapy—a simulation study on needle positioning errors.

    PubMed

    Borot de Battisti, M; Denis de Senneville, B; Maenhout, M; Hautvast, G; Binnekamp, D; Lagendijk, J J W; van Vulpen, M; Moerland, M A

    2016-03-01

    The development of magnetic resonance (MR) guided high dose rate (HDR) brachytherapy for prostate cancer has gained increasing interest for delivering a high tumor dose safely in a single fraction. To support needle placement in the limited workspace inside the closed-bore MRI, a single-needle MR-compatible robot is currently under development at the University Medical Center Utrecht (UMCU). This robotic device taps the needle in a divergent way from a single rotation point into the prostate. With this setup, it is warranted to deliver the irradiation dose by successive insertions of the needle. Although robot-assisted needle placement is expected to be more accurate than manual template-guided insertion, needle positioning errors may occur and are likely to modify the pre-planned dose distribution.In this paper, we propose a dose plan adaptation strategy for HDR prostate brachytherapy with feedback on the needle position: a dose plan is made at the beginning of the interventional procedure and updated after each needle insertion in order to compensate for possible needle positioning errors. The introduced procedure can be used with the single needle MR-compatible robot developed at the UMCU. The proposed feedback strategy was tested by simulating complete HDR procedures with and without feedback on eight patients with different numbers of needle insertions (varying from 4 to 12). In of the cases tested, the number of clinically acceptable plans obtained at the end of the procedure was larger with feedback compared to the situation without feedback. Furthermore, the computation time of the feedback between each insertion was below 100 s which makes it eligible for intra-operative use.

  16. Health Impacts of Climate Change in the Solomon Islands: An Assessment and Adaptation Action Plan

    PubMed Central

    Spickett, Jeffery T; Katscherian, Dianne

    2014-01-01

    The Pacific island countries are particularly vulnerable to the environmental changes wrought by global climate change such as sea level rise, more frequent and intense extreme weather events and increasing temperatures. The potential biophysical changes likely to affect these countries have been identified and it is important that consideration be given to the implications of these changes on the health of their citizens. The potential health impacts of climatic changes on the population of the Solomon Islands were assessed through the use of a Health Impact Assessment framework. The process used a collaborative and consultative approach with local experts to identify the impacts to health that could arise from local environmental changes, considered the risks associated with these and proposed appropriate potential adaptive responses. Participants included knowledgeable representatives from the biophysical, socio-economic, infrastructure, environmental diseases and food sectors. The risk assessments considered both the likelihood and consequences of the health impacts occurring using a qualitative process. To mitigate the adverse effects of the health impacts, an extensive range of potential adaptation strategies were developed. The overall process provided an approach that could be used for further assessments as well as an extensive range of responses which could be used by sectors and to assist future decision making associated with the Solomon Islands’ responses to climate change. PMID:25168977

  17. Health impacts of climate change in the Solomon Islands: an assessment and adaptation action plan.

    PubMed

    Spickett, Jeffery T; Katscherian, Dianne

    2014-09-01

    The Pacific island countries are particularly vulnerable to the environmental changes wrought by global climate change such as sea level rise, more frequent and intense extreme weather events and increasing temperatures. The potential biophysical changes likely to affect these countries have been identified and it is important that consideration be given to the implications of these changes on the health of their citizens. The potential health impacts of climatic changes on the population of the Solomon Islands were assessed through the use of a Health Impact Assessment framework. The process used a collaborative and consultative approach with local experts to identify the impacts to health that could arise from local environmental changes, considered the risks associated with these and proposed appropriate potential adaptive responses. Participants included knowledgeable representatives from the biophysical, socio-economic, infrastructure, environmental diseases and food sectors. The risk assessments considered both the likelihood and consequences of the health impacts occurring using a qualitative process. To mitigate the adverse effects of the health impacts, an extensive range of potential adaptation strategies were developed. The overall process provided an approach that could be used for further assessments as well as an extensive range of responses which could be used by sectors and to assist future decision making associated with the Solomon Islands' responses to climate change. PMID:25168977

  18. Health impacts of climate change in the Solomon Islands: an assessment and adaptation action plan.

    PubMed

    Spickett, Jeffery T; Katscherian, Dianne

    2014-06-25

    The Pacific island countries are particularly vulnerable to the environmental changes wrought by global climate change such as sea level rise, more frequent and intense extreme weather events and increasing temperatures. The potential biophysical changes likely to affect these countries have been identified and it is important that consideration be given to the implications of these changes on the health of their citizens. The potential health impacts of climatic changes on the population of the Solomon Islands were assessed through the use of a Health Impact Assessment framework. The process used a collaborative and consultative approach with local experts to identify the impacts to health that could arise from local environmental changes, considered the risks associated with these and proposed appropriate potential adaptive responses. Participants included knowledgeable representatives from the biophysical, socio-economic, infrastructure, environmental diseases and food sectors. The risk assessments considered both the likelihood and consequences of the health impacts occurring using a qualitative process. To mitigate the adverse effects of the health impacts, an extensive range of potential adaptation strategies were developed. The overall process provided an approach that could be used for further assessments as well as an extensive range of responses which could be used by sectors and to assist future decision making associated with the Solomon Islands' responses to climate change.

  19. Indirect inversions

    NASA Astrophysics Data System (ADS)

    Sergienko, Olga

    2013-04-01

    Since Doug MacAyeal's pioneering studies of the ice-stream basal traction optimizations by control methods, inversions for unknown parameters (e.g., basal traction, accumulation patterns, etc) have become a hallmark of the present-day ice-sheet modeling. The common feature of such inversion exercises is a direct relationship between optimized parameters and observations used in the optimization procedure. For instance, in the standard optimization for basal traction by the control method, ice-stream surface velocities constitute the control data. The optimized basal traction parameters explicitly appear in the momentum equations for the ice-stream velocities (compared to the control data). The inversion for basal traction is carried out by minimization of the cost (or objective, misfit) function that includes the momentum equations facilitated by the Lagrange multipliers. Here, we build upon this idea, and demonstrate how to optimize for parameters indirectly related to observed data using a suite of nested constraints (like Russian dolls) with additional sets of Lagrange multipliers in the cost function. This method opens the opportunity to use data from a variety of sources and types (e.g., velocities, radar layers, surface elevation changes, etc.) in the same optimization process.

  20. ADAPTIVE MANAGEMENT AND PLANNING MODELS FOR CULTURAL RESOURCES IN OIL & GAS FIELDS IN NEW MEXICO AND WYOMING

    SciTech Connect

    Peggy Robinson

    2004-07-01

    This report contains a summary of activities of Gnomon, Inc. and five subcontractors that have taken place during the first six months of 2004 (January 1, 2004-June 30, 2004) under the DOE-NETL cooperative agreement: ''Adaptive Management and Planning Models for Cultural Resources in Oil & Gas Fields in New Mexico and Wyoming'', DE-FC26-02NT15445. Although Gnomon and all five subcontractors completed tasks during these six months, most of the technical experimental work was conducted by the subcontractor, SRI Foundation (SRIF). SRIF created a sensitivity model for the Azotea Mesa area of southeastern New Mexico that rates areas as having a very good chance, a good chance, or a very poor chance of containing cultural resource sites. SRIF suggested that the results of the sensitivity model might influence possible changes in cultural resource management (CRM) practices in the Azote Mesa area of southeastern New Mexico.

  1. ADAPTIVE MANAGEMENT AND PLANNING MODELS FOR CULTURAL RESOURCES IN OIL & GAS FIELDS IN NEW MEXICO AND WYOMING

    SciTech Connect

    Peggy Robinson

    2004-01-01

    This report contains a summary of activities of Gnomon, Inc. and five subcontractors that have taken place during the second six months (July 1, 2003-December 31, 2003) under the DOE-NETL cooperative agreement: ''Adaptive Management and Planning Models for Cultural Resources in Oil & Gas Fields in New Mexico and Wyoming'', DE-FC26-02NT15445. Although Gnomon and all five subcontractors completed tasks during these six months, most of the technical experimental work was conducted by the subcontractor, SRI Foundation (SRIF). SRIF created a sensitivity model for the Loco Hills area of southeastern New Mexico that rates areas as having a very good chance, a good chance, or a very poor chance of containing cultural resource sites. SRIF suggested that the results of the sensitivity model might influence possible changes in cultural resource management (CRM) practices in the Loco Hills area of southeastern New Mexico.

  2. ADAPTIVE MANAGEMENT AND PLANNING MODELS FOR CULTURAL RESOURCES IN OIL & GAS FIELDS IN NEW MEXICO AND WYOMING

    SciTech Connect

    Peggy Robinson

    2005-01-01

    This report summarizes activities that have taken place in the last 6 months (July 2004-December 2004) under the DOE-NETL cooperative agreement ''Adaptive Management and Planning Models for Cultural Resources in Oil and Gas Fields, New Mexico and Wyoming'' DE-FC26-02NT15445. This project examines the practices and results of cultural resource investigation and management in two different oil and gas producing areas of the US: southeastern New Mexico and the Powder River Basin of Wyoming. The project evaluates how cultural resource investigations have been conducted in the past and considers how investigation and management could be pursued differently in the future. The study relies upon full database population for cultural resource inventories and resources and geomorphological studies. These are the basis for analysis of cultural resource occurrence, strategies for finding and evaluating cultural resources, and recommendations for future management practices. Activities can be summarized as occurring in either Wyoming or New Mexico.

  3. Earth Observation in Support of the Development of the Adaptation Plans for Climate Change in Cities: An Application for the Thermal Environment in Athens, Greece

    NASA Astrophysics Data System (ADS)

    Cartalis, C.; Polydoros, A.; Mavrakou, Th.; Asimakopoulos, D. N.

    2014-11-01

    The development of adaptation plans for climate change in cities need to reflect how urban mechanisms are influenced by the transfer of heat and the reflection/emission of electromagnetic radiation. For doing so, a thorough knowledge of a number of urban parameters is needed, namely of the land surface albedo, the land surface emissivity and the land surface temperature. Furthermore, information on land use and land cover as well as a Digital Elevation Model of the area concerned are needed. In this paper, the potential of Earth Observation to support the extraction and spatial/temporal representation of the above parameters, in support of adaptation plans for climate change is examined.

  4. Sea Level Rise Decision Support Tools for Adaptation Planning in Vulnerable Coastal Communities

    NASA Astrophysics Data System (ADS)

    Rozum, J. S.; Marcy, D.

    2015-12-01

    NOAA is involved in a myriad of climate related research and projects that help decision makers and the public understand climate science as well as climate change impacts. The NOAA Office for Coastal Management (OCM) provides data, tools, trainings and technical assistance to coastal resource managers. Beginning in 2011, NOAA OCM began developing a sea level rise and coastal flooding impacts viewer which provides nationally consistent data sets and analyses to help communities with coastal management goals such as: understanding and communicating coastal flood hazards, performing vulnerability assessments and increasing coastal resilience, and prioritizing actions for different inundation/flooding scenarios. The Viewer is available on NOAA's Digital Coast platform: (coast.noaa.gov/ditgitalcoast/tools/slr). In this presentation we will share the lessons learned from our work with coastal decision-makers on the role of coastal flood risk data and tools in helping to shape future land use decisions and policies. We will also focus on a recent effort in California to help users understand the similarities and differences of a growing array of sea level rise decision support tools. NOAA staff and other partners convened a workshop entitled, "Lifting the Fog: Bringing Clarity to Sea Level Rise and Shoreline Change Models and Tools," which was attended by tool develops, science translators and coastal managers with the goal to create a collaborative communication framework to help California coastal decision-makers navigate the range of available sea level rise planning tools, and to inform tool developers of future planning needs. A sea level rise tools comparison matrix will be demonstrated. This matrix was developed as part of this effort and has been expanded to many other states via a partnership with NOAA, Climate Central, and The Nature Conservancy.

  5. Adapting radiotherapy to hypoxic tumours

    NASA Astrophysics Data System (ADS)

    Malinen, Eirik; Søvik, Åste; Hristov, Dimitre; Bruland, Øyvind S.; Rune Olsen, Dag

    2006-10-01

    In the current work, the concepts of biologically adapted radiotherapy of hypoxic tumours in a framework encompassing functional tumour imaging, tumour control predictions, inverse treatment planning and intensity modulated radiotherapy (IMRT) were presented. Dynamic contrast enhanced magnetic resonance imaging (DCEMRI) of a spontaneous sarcoma in the nasal region of a dog was employed. The tracer concentration in the tumour was assumed related to the oxygen tension and compared to Eppendorf histograph measurements. Based on the pO2-related images derived from the MR analysis, the tumour was divided into four compartments by a segmentation procedure. DICOM structure sets for IMRT planning could be derived thereof. In order to display the possible advantages of non-uniform tumour doses, dose redistribution among the four tumour compartments was introduced. The dose redistribution was constrained by keeping the average dose to the tumour equal to a conventional target dose. The compartmental doses yielding optimum tumour control probability (TCP) were used as input in an inverse planning system, where the planning basis was the pO2-related tumour images from the MR analysis. Uniform (conventional) and non-uniform IMRT plans were scored both physically and biologically. The consequences of random and systematic errors in the compartmental images were evaluated. The normalized frequency distributions of the tracer concentration and the pO2 Eppendorf measurements were not significantly different. 28% of the tumour had, according to the MR analysis, pO2 values of less than 5 mm Hg. The optimum TCP following a non-uniform dose prescription was about four times higher than that following a uniform dose prescription. The non-uniform IMRT dose distribution resulting from the inverse planning gave a three times higher TCP than that of the uniform distribution. The TCP and the dose-based plan quality depended on IMRT parameters defined in the inverse planning procedure (fields

  6. Glacial Lake Outburst Flood Risk in Himachal Pradesh, India: An Integrative and Anticipatory Approach to Inform Adaptation Planning

    NASA Astrophysics Data System (ADS)

    Allen, Simon; Linsbauer, Andreas; Huggel, Christian; Singh Randhawa, Surjeet

    2016-04-01

    adaptation measures implemented now will offer dual benefits - reducing not only the current GLOF risk, but also responding to the emerging risk anticipated for the coming decades. Such adaptation strategies (e.g. early warning systems, community preparedness, disaster response planning and land zoning) can be considered "low-regret" measures, i.e, responses that offer immediate benefits to the communities now while also offering benefits over a range of possible future scenarios. Conversely in locations where the formation of new lakes over the coming decades will create an entirely new threat, local authorities would be encouraged to consider long time scales in their climate adaptation planning. This is particularly relevant for new infrastructural developments (residential property, road, hydropower dams etc) where new threats could clearly emerge during the intended lifetime of any constructions.

  7. Classification and assessment of water bodies as adaptive structural measures for flood risk management planning.

    PubMed

    McMinn, William R; Yang, Qinli; Scholz, Miklas

    2010-09-01

    Severe rainfall events have become increasingly common in Europe. Flood defence engineering works are highly capital intensive and can be limited by land availability, leaving land and communities exposed to repeated flooding. Any adaptive drainage structure must have engineered inlets and outlets that control the water level and the rate of release. In Scotland, there are a relatively high number of drinking water reservoirs (operated by Scottish Water), which fall within this defined category and could contribute to flood management control. Reducing the rate of runoff from the upper reaches of a catchment will reduce the volume and peak flows of flood events downstream, thus allowing flood defences to be reduced in size, decreasing the corresponding capital costs. A database of retention basins with flood control potential has been developed for Scotland. The research shows that the majority of small and former drinking water reservoirs are kept full and their spillways are continuously in operation. Utilising some of the available capacity to contribute to flood control could reduce the costs of complying with the EU Flood Directive. Furthermore, the application of a previously developed classification model for Baden in Germany for the Scottish data set showed a lower diversity for basins in Scotland due to less developed infrastructure. The principle value of this approach is a clear and unambiguous categorisation, based on standard variables, which can help to promote communication and understanding between stakeholders.

  8. Megaphylogeny, cell body plans, adaptive zones: causes and timing of eukaryote basal radiations.

    PubMed

    Cavalier-Smith, Thomas

    2009-01-01

    I discuss eukaryote megaphylogeny and the timing of major innovations in the light of multigene trees and the rarity of marine/freshwater evolutionary transitions. The first eukaryotes were aerobic phagotrophs, probably substratum-associated heterotrophic amoeboflagellates. The primary eukaryote bifurcation generated unikonts (ancestrally probably unicentriolar, with a conical microtubular [MT] cytoskeleton) and bikonts (ciliary transformation from anterior cilium to ancestrally gliding posterior cilium; cytoskeleton of ventral MT bands). Unikonts diverged into Amoebozoa with anterior cilia, lost when lobosan broad pseudopods evolved for locomotion, and Choanozoa with posterior cilium and filose pseudopods that became unbranched tentacles/microvilli in holozoa and eventually the choanoflagellate/choanocyte collar. Of choanozoan ancestry, animals evolved epithelia, fibroblasts, eggs, and sperm. Fungi and Ichthyosporea evolved walls. Bikonts, ancestrally with ventral grooves, include three adaptively divergent megagroups: Rhizaria (Retaria and Cercozoa, ancestrally reticulofilose soft-surfaced gliding amoeboflagellates), and the originally planktonic Excavata, and the corticates (Plantae and chromalveolates) that suppressed pseudopodia. Excavata evolved cilia-generated feeding currents for grooval ingestion; corticates evolved cortical alveoli and ciliary hairs. Symbiogenetic origin and transfers of chloroplasts stimulated an explosive radiation of corticates--hard to resolve on multigene trees--and opisthokonts, and ensuing Cambrian explosions of animals and protists. Plantae lost phagotrophy and multiply evolved walls and macroalgae. Apusozoa, with dorsal pellicle and ventral pseudopods, are probably the most divergent bikonts or related to opisthokonts. Eukaryotes probably originated 800-850 My ago. Amoebozoa, Apusozoa, Loukozoa, and Metamonada may be the only extant eukaryote phyla pre-dating Neoproterozoic snowball earth. New subphyla are established for

  9. Megaphylogeny, cell body plans, adaptive zones: causes and timing of eukaryote basal radiations.

    PubMed

    Cavalier-Smith, Thomas

    2009-01-01

    I discuss eukaryote megaphylogeny and the timing of major innovations in the light of multigene trees and the rarity of marine/freshwater evolutionary transitions. The first eukaryotes were aerobic phagotrophs, probably substratum-associated heterotrophic amoeboflagellates. The primary eukaryote bifurcation generated unikonts (ancestrally probably unicentriolar, with a conical microtubular [MT] cytoskeleton) and bikonts (ciliary transformation from anterior cilium to ancestrally gliding posterior cilium; cytoskeleton of ventral MT bands). Unikonts diverged into Amoebozoa with anterior cilia, lost when lobosan broad pseudopods evolved for locomotion, and Choanozoa with posterior cilium and filose pseudopods that became unbranched tentacles/microvilli in holozoa and eventually the choanoflagellate/choanocyte collar. Of choanozoan ancestry, animals evolved epithelia, fibroblasts, eggs, and sperm. Fungi and Ichthyosporea evolved walls. Bikonts, ancestrally with ventral grooves, include three adaptively divergent megagroups: Rhizaria (Retaria and Cercozoa, ancestrally reticulofilose soft-surfaced gliding amoeboflagellates), and the originally planktonic Excavata, and the corticates (Plantae and chromalveolates) that suppressed pseudopodia. Excavata evolved cilia-generated feeding currents for grooval ingestion; corticates evolved cortical alveoli and ciliary hairs. Symbiogenetic origin and transfers of chloroplasts stimulated an explosive radiation of corticates--hard to resolve on multigene trees--and opisthokonts, and ensuing Cambrian explosions of animals and protists. Plantae lost phagotrophy and multiply evolved walls and macroalgae. Apusozoa, with dorsal pellicle and ventral pseudopods, are probably the most divergent bikonts or related to opisthokonts. Eukaryotes probably originated 800-850 My ago. Amoebozoa, Apusozoa, Loukozoa, and Metamonada may be the only extant eukaryote phyla pre-dating Neoproterozoic snowball earth. New subphyla are established for

  10. Dynamically consistent Jacobian inverse for mobile manipulators

    NASA Astrophysics Data System (ADS)

    Ratajczak, Joanna; Tchoń, Krzysztof

    2016-06-01

    By analogy to the definition of the dynamically consistent Jacobian inverse for robotic manipulators, we have designed a dynamically consistent Jacobian inverse for mobile manipulators built of a non-holonomic mobile platform and a holonomic on-board manipulator. The endogenous configuration space approach has been exploited as a source of conceptual guidelines. The new inverse guarantees a decoupling of the motion in the operational space from the forces exerted in the endogenous configuration space and annihilated by the dual Jacobian inverse. A performance study of the new Jacobian inverse as a tool for motion planning is presented.

  11. Online adaptation and verification of VMAT

    SciTech Connect

    Crijns, Wouter; Defraene, Gilles; Depuydt, Tom; Haustermans, Karin; Van Herck, Hans; Maes, Frederik; Van den Heuvel, Frank

    2015-07-15

    practice. Results: The proposed adaptation of a two-arc VMAT plan resulted in the intended CTV{sub mean} (Δ ≤ 3%) and TCP (ΔTCP ≤ 0.001). Moreover, the method assures the intended CI{sub 95%} (Δ ≤ 11%) resulting in lowered rectal NTCP for all cases. Compared to replanning, their adaptation is faster (13 s vs 10 min) and more intuitive. Compared to the current clinical practice, it has a better protection of the healthy tissue. Compared to IMRT, VMAT is more robust to anatomical variations, but it is also less sensitive to the different correction steps. The observed variations of the plan parameters in their database included a linear dependence on the date of treatment planning and on the target radius. The MCS is not retained as QA metric due to a contrasting behavior of its components (LSV and AAV). If three out of four plan parameters (MU, EqFS, AAV, and LSV) need to lie inside a 50% prediction interval (3/4—50%PI), all adapted plans will be accepted. In contrast, all replanned plans do not meet this loose criterion, mainly because they have no connection to the initially optimized and verified plan. Conclusions: A direct (forward) VMAT adaptation performs equally well as (inverse) replanning but is faster and can be extended to real-time adaptation. The prediction intervals for the machine parameters are equivalent to the tolerance tables for couch shifts in the current clinical practice. A 3/4—50%PI QA criterion accepts all the adapted plans but rejects all the replanned plans.

  12. Convergence Properties of a Class of Probabilistic Adaptive Schemes Called Sequential Reproductive Plans. Psychology and Education Series, Technical Report No. 210.

    ERIC Educational Resources Information Center

    Martin, Nancy

    Presented is a technical report concerning the use of a mathematical model describing certain aspects of the duplication and selection processes in natural genetic adaptation. This reproductive plan/model occurs in artificial genetics (the use of ideas from genetics to develop general problem solving techniques for computers). The reproductive…

  13. Inclusive and Individually Adapted Education in Norway Results from a Survey Study in Two Municipalities Focusing the Roles of Headteachers, Teachers and Curriculum Planning

    ERIC Educational Resources Information Center

    Buli-Holmberg, Jorun; Nilsen, Sven; Skogen, Kjell

    2014-01-01

    This article aims to throw light on how the intentions behind inclusive and individually adapted education in Norwegian compulsory schools are followed up in practice with regard to central aspects of the roles of headteachers, teachers and curriculum planning. The study was carried out as a postal survey of compulsory school teachers in two…

  14. Adapting machine learning techniques to censored time-to-event health record data: A general-purpose approach using inverse probability of censoring weighting.

    PubMed

    Vock, David M; Wolfson, Julian; Bandyopadhyay, Sunayan; Adomavicius, Gediminas; Johnson, Paul E; Vazquez-Benitez, Gabriela; O'Connor, Patrick J

    2016-06-01

    Models for predicting the probability of experiencing various health outcomes or adverse events over a certain time frame (e.g., having a heart attack in the next 5years) based on individual patient characteristics are important tools for managing patient care. Electronic health data (EHD) are appealing sources of training data because they provide access to large amounts of rich individual-level data from present-day patient populations. However, because EHD are derived by extracting information from administrative and clinical databases, some fraction of subjects will not be under observation for the entire time frame over which one wants to make predictions; this loss to follow-up is often due to disenrollment from the health system. For subjects without complete follow-up, whether or not they experienced the adverse event is unknown, and in statistical terms the event time is said to be right-censored. Most machine learning approaches to the problem have been relatively ad hoc; for example, common approaches for handling observations in which the event status is unknown include (1) discarding those observations, (2) treating them as non-events, (3) splitting those observations into two observations: one where the event occurs and one where the event does not. In this paper, we present a general-purpose approach to account for right-censored outcomes using inverse probability of censoring weighting (IPCW). We illustrate how IPCW can easily be incorporated into a number of existing machine learning algorithms used to mine big health care data including Bayesian networks, k-nearest neighbors, decision trees, and generalized additive models. We then show that our approach leads to better calibrated predictions than the three ad hoc approaches when applied to predicting the 5-year risk of experiencing a cardiovascular adverse event, using EHD from a large U.S. Midwestern healthcare system.

  15. Adapting machine learning techniques to censored time-to-event health record data: A general-purpose approach using inverse probability of censoring weighting.

    PubMed

    Vock, David M; Wolfson, Julian; Bandyopadhyay, Sunayan; Adomavicius, Gediminas; Johnson, Paul E; Vazquez-Benitez, Gabriela; O'Connor, Patrick J

    2016-06-01

    Models for predicting the probability of experiencing various health outcomes or adverse events over a certain time frame (e.g., having a heart attack in the next 5years) based on individual patient characteristics are important tools for managing patient care. Electronic health data (EHD) are appealing sources of training data because they provide access to large amounts of rich individual-level data from present-day patient populations. However, because EHD are derived by extracting information from administrative and clinical databases, some fraction of subjects will not be under observation for the entire time frame over which one wants to make predictions; this loss to follow-up is often due to disenrollment from the health system. For subjects without complete follow-up, whether or not they experienced the adverse event is unknown, and in statistical terms the event time is said to be right-censored. Most machine learning approaches to the problem have been relatively ad hoc; for example, common approaches for handling observations in which the event status is unknown include (1) discarding those observations, (2) treating them as non-events, (3) splitting those observations into two observations: one where the event occurs and one where the event does not. In this paper, we present a general-purpose approach to account for right-censored outcomes using inverse probability of censoring weighting (IPCW). We illustrate how IPCW can easily be incorporated into a number of existing machine learning algorithms used to mine big health care data including Bayesian networks, k-nearest neighbors, decision trees, and generalized additive models. We then show that our approach leads to better calibrated predictions than the three ad hoc approaches when applied to predicting the 5-year risk of experiencing a cardiovascular adverse event, using EHD from a large U.S. Midwestern healthcare system. PMID:26992568

  16. Inversion of monthly GRACE potentials for climate-based mass transports by a novel technique with locally adapted and increased resolution

    NASA Astrophysics Data System (ADS)

    Michel, Volker; Fischer, Doreen

    2013-04-01

    We show the applicability of a novel method called the Regularized Functional Matching Pursuit (RFMP) to the local analysis of mass transports. We consider monthly GRACE potentials for South America during one year and subtract a temporal mean. The resulting difference fields are denoised with Freeden's spherical wavelets. Finally, the obtained monthly potential anomalies are inverted for volumetric mass density anomalies with the RFMP. The calculated results clearly show seasonal variations in the mass density distribution in the Amazon area. For another application, we consider the detection of droughts and a flood in the summers of 2005 to 2010. The novel technique combines the advantages of global basis functions (spherical harmonics) and local trial functions (splines or wavelets) and yields a resolution which is locally adapted to the detail structure of the solution. We believe that this can contribute to an increased spatial resolution of the result.

  17. Modeled Sea Level Rise Impacts on Coastal Ecosystems at Six Major Estuaries on Florida's Gulf Coast: Implications for Adaptation Planning.

    PubMed

    Geselbracht, Laura L; Freeman, Kathleen; Birch, Anne P; Brenner, Jorge; Gordon, Doria R

    2015-01-01

    The Sea Level Affecting Marshes Model (SLAMM) was applied at six major estuaries along Florida's Gulf Coast (Pensacola Bay, St. Andrews/Choctawhatchee Bays, Apalachicola Bay, Southern Big Bend, Tampa Bay and Charlotte Harbor) to provide quantitative and spatial information on how coastal ecosystems may change with sea level rise (SLR) and to identify how this information can be used to inform adaption planning. High resolution LiDAR-derived elevation data was utilized under three SLR scenarios: 0.7 m, 1 m and 2 m through the year 2100 and uncertainty analyses were conducted on selected input parameters at three sites. Results indicate that the extent, spatial orientation and relative composition of coastal ecosystems at the study areas may substantially change with SLR. Under the 1 m SLR scenario, total predicted impacts for all study areas indicate that coastal forest (-69,308 ha; -18%), undeveloped dry land (-28,444 ha; -2%) and tidal flat (-25,556 ha; -47%) will likely face the greatest loss in cover by the year 2100. The largest potential gains in cover were predicted for saltmarsh (+32,922 ha; +88%), transitional saltmarsh (+23,645 ha; na) and mangrove forest (+12,583 ha; +40%). The Charlotte Harbor and Tampa Bay study areas were predicted to experience the greatest net loss in coastal wetlands The uncertainty analyses revealed low to moderate changes in results when some numerical SLAMM input parameters were varied highlighting the value of collecting long-term sedimentation, accretion and erosion data to improve SLAMM precision. The changes predicted by SLAMM will affect exposure of adjacent human communities to coastal hazards and ecosystem functions potentially resulting in impacts to property values, infrastructure investment and insurance rates. The results and process presented here can be used as a guide for communities vulnerable to SLR to identify and prioritize adaptation strategies that slow and/or accommodate the changes underway. PMID:26207914

  18. Modeled Sea Level Rise Impacts on Coastal Ecosystems at Six Major Estuaries on Florida's Gulf Coast: Implications for Adaptation Planning.

    PubMed

    Geselbracht, Laura L; Freeman, Kathleen; Birch, Anne P; Brenner, Jorge; Gordon, Doria R

    2015-01-01

    The Sea Level Affecting Marshes Model (SLAMM) was applied at six major estuaries along Florida's Gulf Coast (Pensacola Bay, St. Andrews/Choctawhatchee Bays, Apalachicola Bay, Southern Big Bend, Tampa Bay and Charlotte Harbor) to provide quantitative and spatial information on how coastal ecosystems may change with sea level rise (SLR) and to identify how this information can be used to inform adaption planning. High resolution LiDAR-derived elevation data was utilized under three SLR scenarios: 0.7 m, 1 m and 2 m through the year 2100 and uncertainty analyses were conducted on selected input parameters at three sites. Results indicate that the extent, spatial orientation and relative composition of coastal ecosystems at the study areas may substantially change with SLR. Under the 1 m SLR scenario, total predicted impacts for all study areas indicate that coastal forest (-69,308 ha; -18%), undeveloped dry land (-28,444 ha; -2%) and tidal flat (-25,556 ha; -47%) will likely face the greatest loss in cover by the year 2100. The largest potential gains in cover were predicted for saltmarsh (+32,922 ha; +88%), transitional saltmarsh (+23,645 ha; na) and mangrove forest (+12,583 ha; +40%). The Charlotte Harbor and Tampa Bay study areas were predicted to experience the greatest net loss in coastal wetlands The uncertainty analyses revealed low to moderate changes in results when some numerical SLAMM input parameters were varied highlighting the value of collecting long-term sedimentation, accretion and erosion data to improve SLAMM precision. The changes predicted by SLAMM will affect exposure of adjacent human communities to coastal hazards and ecosystem functions potentially resulting in impacts to property values, infrastructure investment and insurance rates. The results and process presented here can be used as a guide for communities vulnerable to SLR to identify and prioritize adaptation strategies that slow and/or accommodate the changes underway.

  19. Adaptation to heavy rainfall events: watershed-community planning of soil and water conservation technologies in Syria

    NASA Astrophysics Data System (ADS)

    Ziadat, Feras; Al-Wadaey, Ahmed; Masri, Zuhair; Sakai, Hirokazu

    2010-05-01

    The Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) and other research, predict a significant future increase in the frequency and intensity of heavy rainfall events in many regions. This increase runoff and soil erosion, and reduce agricultural productivity, as well as increasing risks of flood damage to crops and infrastructure. Implementing adaptation measures and improved land management through erosion control and soil protection are among those that protect water and agriculture and limit their vulnerability. Soil erosion control practices are often based on long-term climatic averages. Special attention is needed to provide protection against average high-return frequency storms as well as severe storms with low-return frequency. Suitable and affordable soil conservation plans, coupled with an appropriate enabling environment, are needed. A watershed and community were selected in the mountainous area of North West Syria. The fields represent the non-tropical highland dry areas and dominated by olive orchards on steep slopes. Farmers were aware of resource degradation and productivity reduction, but lacked financial capital to implement the needed adaptation measures. A micro-credit system was established with the help of the UNDP Global Environment Facility - Small Grants Program (GEF-SGP) with small grants available for each farmer. Haphazard implementation on scattered fields proved inefficient in demonstrating obvious impact. Therefore, each watershed was classified into three erosion risk categories (high, moderate and low), derived from maps of flow accumulation, slope steepness, slope shape and land use. Using field survey of land ownership, the boundaries of 168 farms in the watersheds were mapped. Farmers' fields were classified using the erosion-risk map and considering the on-farm erosion hazard and the off-farm effect on other farmers' fields following the hillslope sequence. More than 60% of the farms were

  20. Adaptive Management and Planning Models for Cultural Resources in Oil and Gas Fields in New Mexico and Wyoming

    SciTech Connect

    Eckerle, William; Hall, Stephen

    2005-12-30

    In 2002, Gnomon, Inc., entered into a cooperative agreement with the U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) for a project entitled, Adaptive Management and Planning Models for Cultural Resources in Oil and Gas Fields in New Mexico and Wyoming (DE-FC26-02NT15445). This project, funded through DOE’s Preferred Upstream Management Practices grant program, examined cultural resource management practices in two major oil- and gas-producing areas, southeastern New Mexico and the Powder River Basin of Wyoming (Figure 1). The purpose of this project was to examine how cultural resources have been investigated and managed and to identify more effective management practices. The project also was designed to build information technology and modeling tools to meet both current and future management needs. The goals of the project were described in the original proposal as follows: Goal 1. Create seamless information systems for the project areas. Goal 2. Examine what we have learned from archaeological work in the southeastern New Mexico oil fields and whether there are better ways to gain additional knowledge more rapidly or at a lower cost. Goal 3. Provide useful sensitivity models for planning, management, and as guidelines for field investigations. Goal 4. Integrate management, investigation, and decision- making in a real-time electronic system. Gnomon, Inc., in partnership with the Wyoming State Historic Preservation Office (WYSHPO) and Western GeoArch Research, carried out the Wyoming portion of the project. SRI Foundation, in partnership with the New Mexico Historic Preservation Division (NMHPD), Statistical Research, Inc., and Red Rock Geological Enterprises, completed the New Mexico component of the project. Both the New Mexico and Wyoming summaries concluded with recommendations how cultural resource management (CRM) processes might be modified based on the findings of this research.

  1. High resolution 3D nonlinear integrated inversion

    NASA Astrophysics Data System (ADS)

    Li, Yong; Wang, Xuben; Li, Zhirong; Li, Qiong; Li, Zhengwen

    2009-06-01

    The high resolution 3D nonlinear integrated inversion method is based on nonlinear theory. Under layer control, the log data from several wells (or all wells) in the study area and seismic trace data adjacent to the wells are input to a network with multiple inputs and outputs and are integratedly trained to obtain an adaptive weight function of the entire study area. Integrated nonlinear mapping relationships are built and updated by the lateral and vertical geologic variations of the reservoirs. Therefore, the inversion process and its inversion results can be constrained and controlled and a stable seismic inversion section with high resolution with velocity inversion, impedance inversion, and density inversion sections, can be gained. Good geologic effects have been obtained in model computation tests and real data processing, which verified that this method has high precision, good practicality, and can be used for quantitative reservoir analysis.

  2. Recombination rate predicts inversion size in Diptera.

    PubMed

    Cáceres, M; Barbadilla, A; Ruiz, A

    1999-09-01

    Most species of the Drosophila genus and other Diptera are polymorphic for paracentric inversions. A common observation is that successful inversions are of intermediate size. We test here the hypothesis that the selected property is the recombination length of inversions, not their physical length. If so, physical length of successful inversions should be negatively correlated with recombination rate across species. This prediction was tested by a comprehensive statistical analysis of inversion size and recombination map length in 12 Diptera species for which appropriate data are available. We found that (1) there is a wide variation in recombination map length among species; (2) physical length of successful inversions varies greatly among species and is inversely correlated with the species recombination map length; and (3) neither the among-species variation in inversion length nor the correlation are observed in unsuccessful inversions. The clear differences between successful and unsuccessful inversions point to natural selection as the most likely explanation for our results. Presumably the selective advantage of an inversion increases with its length, but so does its detrimental effect on fertility due to double crossovers. Our analysis provides the strongest and most extensive evidence in favor of the notion that the adaptive value of inversions stems from their effect on recombination.

  3. Recombination rate predicts inversion size in Diptera.

    PubMed Central

    Cáceres, M; Barbadilla, A; Ruiz, A

    1999-01-01

    Most species of the Drosophila genus and other Diptera are polymorphic for paracentric inversions. A common observation is that successful inversions are of intermediate size. We test here the hypothesis that the selected property is the recombination length of inversions, not their physical length. If so, physical length of successful inversions should be negatively correlated with recombination rate across species. This prediction was tested by a comprehensive statistical analysis of inversion size and recombination map length in 12 Diptera species for which appropriate data are available. We found that (1) there is a wide variation in recombination map length among species; (2) physical length of successful inversions varies greatly among species and is inversely correlated with the species recombination map length; and (3) neither the among-species variation in inversion length nor the correlation are observed in unsuccessful inversions. The clear differences between successful and unsuccessful inversions point to natural selection as the most likely explanation for our results. Presumably the selective advantage of an inversion increases with its length, but so does its detrimental effect on fertility due to double crossovers. Our analysis provides the strongest and most extensive evidence in favor of the notion that the adaptive value of inversions stems from their effect on recombination. PMID:10471710

  4. Clinical Implementation of an Online Adaptive Plan-of-the-Day Protocol for Nonrigid Motion Management in Locally Advanced Cervical Cancer IMRT

    SciTech Connect

    Heijkoop, Sabrina T. Langerak, Thomas R.; Quint, Sandra; Bondar, Luiza; Mens, Jan Willem M.; Heijmen, Ben J.M.; Hoogeman, Mischa S.

    2014-11-01

    Purpose: To evaluate the clinical implementation of an online adaptive plan-of-the-day protocol for nonrigid target motion management in locally advanced cervical cancer intensity modulated radiation therapy (IMRT). Methods and Materials: Each of the 64 patients had four markers implanted in the vaginal fornix to verify the position of the cervix during treatment. Full and empty bladder computed tomography (CT) scans were acquired prior to treatment to build a bladder volume-dependent cervix-uterus motion model for establishment of the plan library. In the first phase of clinical implementation, the library consisted of one IMRT plan based on a single model-predicted internal target volume (mpITV), covering the target for the whole pretreatment observed bladder volume range, and a 3D conformal radiation therapy (3DCRT) motion-robust backup plan based on the same mpITV. The planning target volume (PTV) combined the ITV and nodal clinical target volume (CTV), expanded with a 1-cm margin. In the second phase, for patients showing >2.5-cm bladder-induced cervix-uterus motion during planning, two IMRT plans were constructed, based on mpITVs for empty-to-half-full and half-full-to-full bladder. In both phases, a daily cone beam CT (CBCT) scan was acquired to first position the patient based on bony anatomy and nodal targets and then select the appropriate plan. Daily post-treatment CBCT was used to verify plan selection. Results: Twenty-four and 40 patients were included in the first and second phase, respectively. In the second phase, 11 patients had two IMRT plans. Overall, an IMRT plan was used in 82.4% of fractions. The main reasons for selecting the motion-robust backup plan were uterus outside the PTV (27.5%) and markers outside their margin (21.3%). In patients with two IMRT plans, the half-full-to-full bladder plan was selected on average in 45% of the first 12 fractions, which was reduced to 35% in the last treatment fractions. Conclusions: The implemented

  5. SU-E-J-73: Extension of a Clinical OIS/EMR/R&V System to Deliver Safe and Efficient Adaptive Plan-Of-The-Day Treatments Using a Fully Customizable Plan-Library-Based Workflow

    SciTech Connect

    Akhiat, A.; Kanis, A.P.; Penninkhof, J.J.; Sodjo, S.; O’Neill, T.; Quint, S.; Doorn, X. van; Schillemans, W.; Heijmen, B.; Hoogeman, M.; Linton, N.; Coleman, A.

    2015-06-15

    Purpose: To extend a clinical Record and Verify (R&V) system to enable a safe and fast workflow for Plan-of-the-Day (PotD) adaptive treatments based on patient-specific plan libraries. Methods: Plan libraries for PotD adaptive treatments contain for each patient several pre-treatment generated treatment plans. They may be generated for various patient anatomies or CTV-PTV margins. For each fraction, a Cone Beam CT scan is acquired to support the selection of the plan that best fits the patient’s anatomy-of-the-day. To date, there are no commercial R&V systems that support PotD delivery strategies. Consequently, the clinical workflow requires many manual interventions. Moreover, multiple scheduled plans have a high risk of excessive dose delivery. In this work we extended a commercial R&V system (MOSAIQ) to support PotD workflows using IQ-scripting. The PotD workflow was designed after extensive risk analysis of the manual procedure, and all identified risks were incorporated as logical checks. Results: All manual PotD activities were automated. The workflow first identifies if the patient is scheduled for PotD, then performs safety checks, and continues to treatment plan selection only if no issues were found. The user selects the plan to deliver from a list of candidate plans. After plan selection, the workflow makes the treatment fields of the selected plan available for delivery by adding them to the treatment calendar. Finally, control is returned to the R&V system to commence treatment. Additional logic was added to incorporate off-line changes such as updating the plan library. After extensive testing including treatment fraction interrupts and plan-library updates during the treatment course, the workflow is running successfully in a clinical pilot, in which 35 patients have been treated since October 2014. Conclusion: We have extended a commercial R&V system for improved safety and efficiency in library-based adaptive strategies enabling a wide

  6. Coastal Adaptation Planning for Sea Level Rise and Extremes: A Global Model for Adaptation Decision-making at the Local Level Given Uncertain Climate Projections

    NASA Astrophysics Data System (ADS)

    Turner, D.

    2014-12-01

    Understanding the potential economic and physical impacts of climate change on coastal resources involves evaluating a number of distinct adaptive responses. This paper presents a tool for such analysis, a spatially-disaggregated optimization model for adaptation to sea level rise (SLR) and storm surge, the Coastal Impact and Adaptation Model (CIAM). This decision-making framework fills a gap between very detailed studies of specific locations and overly aggregate global analyses. While CIAM is global in scope, the optimal adaptation strategy is determined at the local level, evaluating over 12,000 coastal segments as described in the DIVA database (Vafeidis et al. 2006). The decision to pursue a given adaptation measure depends on local socioeconomic factors like income, population, and land values and how they develop over time, relative to the magnitude of potential coastal impacts, based on geophysical attributes like inundation zones and storm surge. For example, the model's decision to protect or retreat considers the costs of constructing and maintaining coastal defenses versus those of relocating people and capital to minimize damages from land inundation and coastal storms. Uncertain storm surge events are modeled with a generalized extreme value distribution calibrated to data on local surge extremes. Adaptation is optimized for the near-term outlook, in an "act then learn then act" framework that is repeated over the model time horizon. This framework allows the adaptation strategy to be flexibly updated, reflecting the process of iterative risk management. CIAM provides new estimates of the economic costs of SLR; moreover, these detailed results can be compactly represented in a set of adaptation and damage functions for use in integrated assessment models. Alongside the optimal result, CIAM evaluates suboptimal cases and finds that global costs could increase by an order of magnitude, illustrating the importance of adaptive capacity and coastal policy.

  7. ADAPTIVE MANAGEMENT AND PLANNING MODELS FOR CULTURAL RESOURCES IN OIL & GAS FIELDS IN NEW MEXICO AND WYOMING

    SciTech Connect

    Peggy Robinson

    2005-07-01

    This report summarizes activities that have taken place in the last six (6) months (January 2005-June 2005) under the DOE-NETL cooperative agreement ''Adaptive Management and Planning Models for Cultural Resources in Oil and Gas Fields, New Mexico and Wyoming'' DE-FC26-02NT15445. This project examines the practices and results of cultural resource investigation and management in two different oil and gas producing areas of the United States: southeastern New Mexico and the Powder River Basin of Wyoming. The project evaluates how cultural resource investigations have been conducted in the past and considers how investigation and management could be pursued differently in the future. The study relies upon full database population for cultural resource inventories and resources and geomorphological studies. These are the basis for analysis of cultural resource occurrence, strategies for finding and evaluating cultural resources, and recommendations for future management practices. Activities can be summarized as occurring in either Wyoming or New Mexico. Gnomon as project lead, worked in both areas.

  8. ADAPTIVE MANAGEMENT AND PLANNING MODELS FOR CULTURAL RESOURCES IN OIL AND GAS IN NEW MEXICO AND WYOMING

    SciTech Connect

    Peggy Robinson

    2003-07-25

    This report contains a summary of activities of Gnomon, Inc. and five sub-contractors that have taken place during the first six months (January 1, 2003--June 30, 2003) under the DOE-NETL cooperative agreement: ''Adaptive Management and Planning Models for Cultural Resources in Oil & Gas Fields in New Mexico and Wyoming'', DE-FC26-02NT15445. Gnomon, Inc. and all five (5) subcontractors have agreed on a process for the framework of this two-year project. They have also started gathering geomorphological information and entering cultural resource data into databases that will be used to create models later in the project. This data is being gathered in both the Power River Basin of Wyoming, and the Southeastern region of New Mexico. Several meetings were held with key players in this project to explain the purpose of the research, to obtain feedback and to gain support. All activities have been accomplished on time and within budget with no major setbacks.

  9. Scale invariant feature transform in adaptive radiation therapy: a tool for deformable image registration assessment and re-planning indication

    NASA Astrophysics Data System (ADS)

    Paganelli, Chiara; Peroni, Marta; Riboldi, Marco; Sharp, Gregory C.; Ciardo, Delia; Alterio, Daniela; Orecchia, Roberto; Baroni, Guido

    2013-01-01

    Adaptive radiation therapy (ART) aims at compensating for anatomic and pathological changes to improve delivery along a treatment fraction sequence. Current ART protocols require time-consuming manual updating of all volumes of interest on the images acquired during treatment. Deformable image registration (DIR) and contour propagation stand as a state of the ART method to automate the process, but the lack of DIR quality control methods hinder an introduction into clinical practice. We investigated the scale invariant feature transform (SIFT) method as a quantitative automated tool (1) for DIR evaluation and (2) for re-planning decision-making in the framework of ART treatments. As a preliminary test, SIFT invariance properties at shape-preserving and deformable transformations were studied on a computational phantom, granting residual matching errors below the voxel dimension. Then a clinical dataset composed of 19 head and neck ART patients was used to quantify the performance in ART treatments. For the goal (1) results demonstrated SIFT potential as an operator-independent DIR quality assessment metric. We measured DIR group systematic residual errors up to 0.66 mm against 1.35 mm provided by rigid registration. The group systematic errors of both bony and all other structures were also analyzed, attesting the presence of anatomical deformations. The correct automated identification of 18 patients who might benefit from ART out of the total 22 cases using SIFT demonstrated its capabilities toward goal (2) achievement.

  10. Inverse Floatation

    NASA Astrophysics Data System (ADS)

    Nath, Saurabh; Mukherjee, Anish; Chatterjee, Souvick; Ganguly, Ranjan; Sen, Swarnendu; Mukhopadhyay, Achintya; Boreyko, Jonathan

    2014-11-01

    We have observed that capillarity forces may cause floatation in a few non-intuitive configurations. These may be divided into 2 categories: i) floatation of heavier liquid droplets on lighter immiscible ones and ii) fully submerged floatation of lighter liquid droplets in a heavier immiscible medium. We call these counter-intuitive because of the inverse floatation configuration. For case (i) we have identified and studied in detail the several factors affecting the shape and maximum volume of the floating drop. We used water and vegetable oil combinations as test fluids and established the relation between Bond Number and maximum volume contained in a floating drop (in the order of μL). For case (ii), we injected vegetable oil drop-wise into a pool of water. The fully submerged configuration of the drop is not stable and a slight perturbation to the system causes the droplet to burst and float in partially submerged condition. Temporal variation of a characteristic length of the droplet is analyzed using MATLAB image processing. The constraint of small Bond Number establishes the assumption of lubrication regime in the thin gap. A brief theoretical formulation also shows the temporal variation of the gap thickness. Jadavpur University, Jagadis Bose Centre of Excellence, Virginia Tech.

  11. Darwin's "strange inversion of reasoning".

    PubMed

    Dennett, Daniel

    2009-06-16

    Darwin's theory of evolution by natural selection unifies the world of physics with the world of meaning and purpose by proposing a deeply counterintuitive "inversion of reasoning" (according to a 19th century critic): "to make a perfect and beautiful machine, it is not requisite to know how to make it" [MacKenzie RB (1868) (Nisbet & Co., London)]. Turing proposed a similar inversion: to be a perfect and beautiful computing machine, it is not requisite to know what arithmetic is. Together, these ideas help to explain how we human intelligences came to be able to discern the reasons for all of the adaptations of life, including our own.

  12. SU-E-J-229: Quantitative Assessment for Timely Adaptive Re-Planning Using Weekly Dose Monitoring for Head and Neck Cancer

    SciTech Connect

    Shang, Q; Liu, H; Greskovich, J; Koyfman, S; Xia, P; Li, Z

    2014-06-01

    Purpose: For patients with head and neck (HN) cancer, mid-course adaptive radiation therapy (ART) is a common practice in our institution to accommodate anatomic changes. The aim of the study is to evaluate whether dose re-calculation on weekly verification images can provide quantitative assessment for timely adaptive re-planning with daily image-guided intensity modulated radiotherapy (IMRT). Methods: We retrospectively selected sixty daily verification images acquired on CT-on-rail/CBCT from ten HN patients. These image sets were typically a week apart. Among these patients, six patients received a mid-course ART. Contours of the tumors and organ-at-risks (OARs) were manually delineated by a physician on each verification CT. After placing the treatment iso-center on the verification CTs according to the recorded clinical shifts, daily dose was re-calculated with the same beam configuration as the original plan. For the purpose of this study, electron densities for both verification CTs and planning CTs were set to 1.0 g/cm3. Results: Two patients had D99 of the CTV < 97% of the planned dose for more than three fractions due to remarkable tumor volume shrinkages. D-max of the spinal cord exceeded a tolerance of 45 Gy for four fractions in additional two patients. D-mean of the parotid increased within 25% of the planned value. D-max of the brainstem and D-mean of the oral cavity did not show significant variation. If the re-planning criteria included D99 of the CTV < 97% of the planned dose and D-max of the spinal cord > 45 Gy, two out ten patients required ART at week 2 and two patients required ART at week 3, respectively. Conclusion: Weekly dose monitoring with re-calculation on verification images can provide quantitative dose guidance for timely adaptive re-planning. Future work will include accumulative dose analysis for the decision of adaptive re-planning. The study is supported in part by Siemens Medical Solutions.

  13. Source Inversion Validation: Quantifying Uncertainties in Earthquake Source Inversions

    NASA Astrophysics Data System (ADS)

    Mai, P. M.; Page, M. T.; Schorlemmer, D.

    2010-12-01

    Earthquake source inversions image the spatio-temporal rupture evolution on one or more fault planes using seismic and/or geodetic data. Source inversion methods thus represent an important research tool in seismology to unravel the complexity of earthquake ruptures. Subsequently, source-inversion results are used to study earthquake mechanics, to develop spontaneous dynamic rupture models, to build models for generating rupture realizations for ground-motion simulations, and to perform Coulomb-stress modeling. In all these applications, the underlying finite-source rupture models are treated as “data” (input information), but the uncertainties in these data (i.e. source models obtained from solving an inherently ill-posed inverse problem) are hardly known, and almost always neglected. The Source Inversion Validation (SIV) project attempts to better understand the intra-event variability of earthquake rupture models. We plan to build a long-standing and rigorous testing platform to examine the current state-of-the-art in earthquake source inversion that also facilitates to develop robust approaches to quantify rupture-model uncertainties. Our contribution reviews the current status of the SIV project, recent forward-modeling tests for point and extended sources in layered media, and discusses the strategy of the SIV-project for the coming years.

  14. Towards an equitable allocation of the cost of a global change adaptation plan at the river basin scale: going beyond the perfect cooperation assumption

    NASA Astrophysics Data System (ADS)

    Girard, Corentin; Rinaudo, Jean-Daniel; Pulido-Velázquez, Manuel

    2015-04-01

    Adaptation to global change is a key issue in the planning of water resource systems in a changing world. Adaptation has to be efficient, but also equitable in the share of the costs of joint adaptation at the river basin scale. Least-cost hydro-economic optimization models have been helpful at defining efficient adaptation strategies. However, they often rely on the assumption of a "perfect cooperation" among the stakeholders, required for reaching the optimal solution. Nowadays, most adaptation decisions have to be agreed among the different actors in charge of their implementation, thus challenging the validity of a perfect command-and-control solution. As a first attempt to over-pass this limitation, our work presents a method to allocate the cost of an efficient adaptation programme of measures among the different stakeholders at the river basin scale. Principles of equity are used to define cost allocation scenarios from different perspectives, combining elements from cooperative game theory and axioms from social justice to bring some "food for thought" in the decision making process of adaptation. To illustrate the type of interactions between stakeholders in a river basin, the method has been applied in a French case study, the Orb river basin. Located on the northern rim of the Mediterranean Sea, this river basin is experiencing changes in demand patterns, and its water resources will be impacted by climate change, calling for the design of an adaptation plan. A least-cost river basin optimization model (LCRBOM) has been developed under GAMS to select the combination of demand- and supply-side adaptation measures that allows meeting quantitative water management targets at the river basin scale in a global change context. The optimal adaptation plan encompasses measures in both agricultural and urban sectors, up-stream and down-stream of the basin, disregarding the individual interests of the stakeholders. In order to ensure equity in the cost allocation

  15. TH-E-17A-09: High Quality and Artifact-Free 4D Cone Beam CT and Its Application in Adaptive Treatment Planning

    SciTech Connect

    Niu, K; Li, K; Smilowitz, J; Chen, G

    2014-06-15

    Purpose: To develop a high quality 4D cone beam CT (4DCBCT) method that is immune to patient/couch truncations and to investigate its application in adaptive replanning of lung XRT. Methods: In this study, IRB-approved human subject CBCT data was acquired using a Varian on-board imager with 1 minute rotation time. The acquired projection data was retrospectively sorted into 20 respiratory phase bins, from which 4DCBCT images with high SNR and high temporal resolution were generated using Prior Image Constrained Compressed Sensing (PICCS). Couch and patient truncations generate strong data inconsistency in the projection data and artifacts in the 4DCBCT image. They were addressed using an adaptive PICCS method. The artifact-free PICCS-4DCBCT images were used to generate adaptive treatment plans for the same patient at the 10th (day 21) and 30th (day 47) fractions. Dosimetric impacts with and without PICCS- 4DCBCT were evaluated by isodose distributions, DVHs, and other dosimetric factors. Results: The adaptive PICCS-4DCBCT method improves image quality by removing residue truncation artifacts; measured universal image quality increased 37%. The isodose lines and DVHs with PICCS-4DCBCT-based adaptive replanning were significantly more conformal to PTV than without replanning due to changes in patient anatomy caused by progress of the treatment. The mean dose to PTV at the 10th fraction was 63.1Gy with replanning and 64.2Gy without replanning, where the prescribed dose was 60Gy, in 2Gy × 30 fractions. The mean dose to PTV at the 30th fraction was 61.6Gy with replanning and 64.9Gy without replanning. Lung V20 was 37.1%, 41.9% and 43.3% for original plan, 10th fraction plan and 30th fraction plan; with re-planning, Lung V20 was 37.1%, 32%, 27.8%. Conclusion: 4DCBCT imaging using adaptive PICCS is able to generate high quality, artifact-free images that potentially can be used to create replanning for improving radiotherapy of the lung. K Niu, K Li, J Smilowitz: Nothing

  16. Multidimensional NMR inversion without Kronecker products: Multilinear inversion.

    PubMed

    Medellín, David; Ravi, Vivek R; Torres-Verdín, Carlos

    2016-08-01

    Multidimensional NMR inversion using Kronecker products poses several challenges. First, kernel compression is only possible when the kernel matrices are separable, and in recent years, there has been an increasing interest in NMR sequences with non-separable kernels. Second, in three or more dimensions, the singular value decomposition is not unique; therefore kernel compression is not well-defined for higher dimensions. Without kernel compression, the Kronecker product yields matrices that require large amounts of memory, making the inversion intractable for personal computers. Finally, incorporating arbitrary regularization terms is not possible using the Lawson-Hanson (LH) or the Butler-Reeds-Dawson (BRD) algorithms. We develop a minimization-based inversion method that circumvents the above problems by using multilinear forms to perform multidimensional NMR inversion without using kernel compression or Kronecker products. The new method is memory efficient, requiring less than 0.1% of the memory required by the LH or BRD methods. It can also be extended to arbitrary dimensions and adapted to include non-separable kernels, linear constraints, and arbitrary regularization terms. Additionally, it is easy to implement because only a cost function and its first derivative are required to perform the inversion. PMID:27209370

  17. Multidimensional NMR inversion without Kronecker products: Multilinear inversion

    NASA Astrophysics Data System (ADS)

    Medellín, David; Ravi, Vivek R.; Torres-Verdín, Carlos

    2016-08-01

    Multidimensional NMR inversion using Kronecker products poses several challenges. First, kernel compression is only possible when the kernel matrices are separable, and in recent years, there has been an increasing interest in NMR sequences with non-separable kernels. Second, in three or more dimensions, the singular value decomposition is not unique; therefore kernel compression is not well-defined for higher dimensions. Without kernel compression, the Kronecker product yields matrices that require large amounts of memory, making the inversion intractable for personal computers. Finally, incorporating arbitrary regularization terms is not possible using the Lawson-Hanson (LH) or the Butler-Reeds-Dawson (BRD) algorithms. We develop a minimization-based inversion method that circumvents the above problems by using multilinear forms to perform multidimensional NMR inversion without using kernel compression or Kronecker products. The new method is memory efficient, requiring less than 0.1% of the memory required by the LH or BRD methods. It can also be extended to arbitrary dimensions and adapted to include non-separable kernels, linear constraints, and arbitrary regularization terms. Additionally, it is easy to implement because only a cost function and its first derivative are required to perform the inversion.

  18. Tadpole transport logistics in a Neotropical poison frog: indications for strategic planning and adaptive plasticity in anuran parental care

    PubMed Central

    2013-01-01

    Introduction Individuals should aim to adjust their parental behaviours in order to maximize the success of their offspring but minimize associated costs. Plasticity in parental care is well documented from various bird, mammal and fish species, whereas amphibians were traditionally assumed as being highly instinct-bound. Therefore, little is known about ‘higher’ cognitive abilities of amphibians, such as strategic planning and behavioural flexibility. Dendrobatid frogs have evolved a remarkable diversity of parental behaviours. The most noticeable of these behaviours is tadpole transport, which is obligatory in almost all species. Nonetheless, there is limited knowledge about spatial and temporal patterns of tadpole transport and the possible existence of behavioural plasticity on the individual level. In this study, we investigated correlates of tadpole transport behaviour in a natural population of the dendrobatid frog Allobates femoralis during five years. Results Tadpole transport was predominantly observed during morning hours. Although tadpoles were carried almost exclusively by males (N = 119), we also observed ten females performing this task. The parentage analysis revealed that in all cases females transported their own offspring. In contrast, four tadpole-carrying males were not the genetic fathers of the larvae they were transporting. The average clutch size of 20 eggs and our observation of an average of 8 tadpoles on the back of transporting individuals indicate that frogs do not carry entire clutches at once, and/or that they distribute their larvae across several water bodies. Contrary to the predictions from a hypothetical random search for deposition sites, the number of transported tadpoles was higher in males that travelled over longer distances. Conclusions Our results suggest a strong selective pressure on males to shift the time invested in tadpole transport to periods of low intra-specific competition. The number of tadpoles on the

  19. How urban system vulnerabilities to flooding could be assessed to improve resilience and adaptation in spatial planning

    NASA Astrophysics Data System (ADS)

    Pasi, Riccardo; Viavattene, Christophe; La Loggia, Goffredo

    2016-04-01

    Natural hazards damage assets and infrastructure inducing disruptions to urban functions and key daily services. These disruptions may be short or long with a variable spatial scale of impact. From an urban planning perspective, measuring these disruptions and their consequences at an urban scale is fundamental in order to develop more resilient cities. Whereas the assessment of physical vulnerabilities and direct damages is commonly addressed, new methodologies for assessing the systemic vulnerability at the urban scale are required to reveal these disruptions and their consequences. Physical and systemic vulnerability should be measured in order to reflect the multifaceted fragility of cities in the face of external stress, both in terms of the natural/built environment and socio-economic sphere. Additionally, a systemic approach allows the consideration of vulnerability across different spatial scales, as impacts may vary and be transmitted across local, regional or national levels. Urban systems are spatially distributed and the nature of this can have significant effects on flood impacts. The proposed approach identifies the vulnerabilities of flooding within urban contexts, including both in terms of single elementary units (buildings, infrastructures, people, etc.) and systemic functioning (urban functions and daily life networks). Direct losses are appraised initially using conventional methodologies (e.g. depth-damage functions). This aims to both understand the spatial distribution of physical vulnerability and associated losses and, secondly, to identify the most vulnerable building types and ways to improve the physical adaptation of our cities, proposing changes to building codes, design principles and other municipal regulation tools. The subsequent systemic approach recognises the city as a collection of sub-systems or functional units (such as neighbourhoods and suburbs) providing key daily services for inhabitants (e.g. healthcare facilities

  20. L1 Adaptive Control Law for Flexible Space Launch Vehicle and Proposed Plan for Flight Test Validation

    NASA Technical Reports Server (NTRS)

    Kharisov, Evgeny; Gregory, Irene M.; Cao, Chengyu; Hovakimyan, Naira

    2008-01-01

    This paper explores application of the L1 adaptive control architecture to a generic flexible Crew Launch Vehicle (CLV). Adaptive control has the potential to improve performance and enhance safety of space vehicles that often operate in very unforgiving and occasionally highly uncertain environments. NASA s development of the next generation space launch vehicles presents an opportunity for adaptive control to contribute to improved performance of this statically unstable vehicle with low damping and low bending frequency flexible dynamics. In this paper, we consider the L1 adaptive output feedback controller to control the low frequency structural modes and propose steps to validate the adaptive controller performance utilizing one of the experimental test flights for the CLV Ares-I Program.

  1. Parotid Glands Dose-Effect Relationships Based on Their Actually Delivered Doses: Implications for Adaptive Re-Planning in Radiotherapy of Head and Neck Cancer

    PubMed Central

    Hunter, Klaudia U.; Fernandes, Laura; Vineberg, Karen A.; McShan, Daniel; Antonuk, Alan E.; Cornwall, Craig; Feng, Mary; Schipper, Mathew; Balter, James; Eisbruch, Avraham

    2013-01-01

    Purpose Doses actually delivered to the parotid glands during radiotherapy often exceed planned doses. We hypothesized that the delivered doses correlate better with parotid salivary output than the planned doses, used in all previous studies, and that determining these correlations will help decisions regarding adaptive re-planning (ART) aimed at reducing the delivered doses. Methods and Materials Prospective study: oropharyngeal cancer patients treated definitively with chemo-irradiation underwent daily cone beam CT (CBCT) with clinical set-up alignment based on C2 posterior edge. Parotid glands in the CBCTs were aligned by deformable registration to calculate cumulative delivered doses. Stimulated salivary flow rates were measured separately from each parotid gland pretherapy and periodically posttherapy. Results 36 parotid glands of 18 patients were analyzed. Average mean planned doses was 32 Gy and differences from planned to delivered mean gland doses were −4.9 to +8.4 Gy, median difference +2.2 Gy in glands whose delivered doses increased relative to planned. Both planned and delivered mean doses were significantly correlated with post-treatment salivary outputs at almost all post-therapy time points, without statistically significant differences in the correlations. Large dispersions [on average, standard deviation (SD) 3.6 Gy] characterized the dose/effect relationships for both. The differences between the cumulative delivered doses and planned doses were evident already at first fraction (r=0.92, p<0.0001) due to complex set-up deviations, e.g. rotations and neck articulations, uncorrected by the translational clinical alignments. Conclusions After daily translational set-up corrections, differences between planned and delivered doses in most glands were small relative to the SDs of the dose/saliva data, suggesting that ART is not likely to gain measurable salivary output improvement in most cases. These differences were observed already at first

  2. Human inversions and their functional consequences

    PubMed Central

    Puig, Marta; Casillas, Sònia; Villatoro, Sergi

    2015-01-01

    Polymorphic inversions are a type of structural variants that are difficult to analyze owing to their balanced nature and the location of breakpoints within complex repeated regions. So far, only a handful of inversions have been studied in detail in humans and current knowledge about their possible functional effects is still limited. However, inversions have been related to phenotypic changes and adaptation in multiple species. In this review, we summarize the evidences of the functional impact of inversions in the human genome. First, given that inversions have been shown to inhibit recombination in heterokaryotes, chromosomes displaying different orientation are expected to evolve independently and this may lead to distinct gene-expression patterns. Second, inversions have a role as disease-causing mutations both by directly affecting gene structure or regulation in different ways, and by predisposing to other secondary arrangements in the offspring of inversion carriers. Finally, several inversions show signals of being selected during human evolution. These findings illustrate the potential of inversions to have phenotypic consequences also in humans and emphasize the importance of their inclusion in genome-wide association studies. PMID:25998059

  3. A biologically based model for the integration of sensory-motor contingencies in rules and plans: a prefrontal cortex based extension of the Distributed Adaptive Control architecture.

    PubMed

    Duff, Armin; Fibla, Marti Sanchez; Verschure, Paul F M J

    2011-06-30

    Intelligence depends on the ability of the brain to acquire and apply rules and representations. At the neuronal level these properties have been shown to critically depend on the prefrontal cortex. Here we present, in the context of the Distributed Adaptive Control architecture (DAC), a biologically based model for flexible control and planning based on key physiological properties of the prefrontal cortex, i.e. reward modulated sustained activity and plasticity of lateral connectivity. We test the model in a series of pertinent tasks, including multiple T-mazes and the Tower of London that are standard experimental tasks to assess flexible control and planning. We show that the model is both able to acquire and express rules that capture the properties of the task and to quickly adapt to changes. Further, we demonstrate that this biomimetic self-contained cognitive architecture generalizes to planning. In addition, we analyze the extended DAC architecture, called DAC 6, as a model that can be applied for the creation of intelligent and psychologically believable synthetic agents. PMID:21138760

  4. Toward Online Adaptive Hyperthermia Treatment Planning: Correlation Between Measured and Simulated Specific Absorption Rate Changes Caused by Phase Steering in Patients

    SciTech Connect

    Kok, H. Petra; Ciampa, Silvia; Kroon-Oldenhof, Rianne de; Steggerda-Carvalho, Eva J.; Stam, Gerard van; Zum Vörde Sive Vörding, Paul J.; Stalpers, Lukas J.A.; Geijsen, Elisabeth D.; Bardati, Fernando; Bel, Arjan; Crezee, Johannes

    2014-10-01

    Purpose: Hyperthermia is the clinical application of heat, in which tumor temperatures are raised to 40°C to 45°C. This proven radiation and chemosensitizer significantly improves clinical outcome for several tumor sites. Earlier studies of the use of pre-treatment planning for hyperthermia showed good qualitative but disappointing quantitative reliability. The purpose of this study was to investigate whether hyperthermia treatment planning (HTP) can be used more reliably for online adaptive treatment planning during locoregional hyperthermia treatments. Methods and Materials: This study included 78 treatment sessions for 15 patients with non-muscle-invasive bladder cancer. At the start of treatments, temperature rise measurements were performed with 3 different antenna settings optimized for each patient, from which the absorbed power (specific absorption rate [SAR]) was derived. HTP was performed based on a computed tomography (CT) scan in treatment position with the bladder catheter in situ. The SAR along the thermocouple tracks was extracted from the simulated SAR distributions. Correlations between measured and simulated (average) SAR values were determined. To evaluate phase steering, correlations between the changes in simulated and measured SAR values averaged over the thermocouple probe were determined for all 3 combinations of antenna settings. Results: For 42% of the individual treatment sessions, the correlation coefficient between measured and simulated SAR profiles was higher than 0.5, whereas 58% showed a weak correlation (R of <0.5). The overall correlation coefficient between measured and simulated average SAR was weak (R=0.31; P<.001). The measured and simulated changes in average SAR after adapting antenna settings correlated much better (R=0.70; P<.001). The ratio between the measured and simulated quotients of maximum and average SARs was 1.03 ± 0.26 (mean ± SD), indicating that HTP can also correctly predict the relative amplitude of

  5. An Atlas-Based Electron Density Mapping Method for Magnetic Resonance Imaging (MRI)-Alone Treatment Planning and Adaptive MRI-Based Prostate Radiation Therapy

    SciTech Connect

    Dowling, Jason A.; Lambert, Jonathan; Parker, Joel; Salvado, Olivier; Fripp, Jurgen; Capp, Anne; Wratten, Chris; Denham, James W.; Greer, Peter B.

    2012-05-01

    Purpose: Prostate radiation therapy dose planning directly on magnetic resonance imaging (MRI) scans would reduce costs and uncertainties due to multimodality image registration. Adaptive planning using a combined MRI-linear accelerator approach will also require dose calculations to be performed using MRI data. The aim of this work was to develop an atlas-based method to map realistic electron densities to MRI scans for dose calculations and digitally reconstructed radiograph (DRR) generation. Methods and Materials: Whole-pelvis MRI and CT scan data were collected from 39 prostate patients. Scans from 2 patients showed significantly different anatomy from that of the remaining patient population, and these patients were excluded. A whole-pelvis MRI atlas was generated based on the manually delineated MRI scans. In addition, a conjugate electron-density atlas was generated from the coregistered computed tomography (CT)-MRI scans. Pseudo-CT scans for each patient were automatically generated by global and nonrigid registration of the MRI atlas to the patient MRI scan, followed by application of the same transformations to the electron-density atlas. Comparisons were made between organ segmentations by using the Dice similarity coefficient (DSC) and point dose calculations for 26 patients on planning CT and pseudo-CT scans. Results: The agreement between pseudo-CT and planning CT was quantified by differences in the point dose at isocenter and distance to agreement in corresponding voxels. Dose differences were found to be less than 2%. Chi-squared values indicated that the planning CT and pseudo-CT dose distributions were equivalent. No significant differences (p > 0.9) were found between CT and pseudo-CT Hounsfield units for organs of interest. Mean {+-} standard deviation DSC scores for the atlas-based segmentation of the pelvic bones were 0.79 {+-} 0.12, 0.70 {+-} 0.14 for the prostate, 0.64 {+-} 0.16 for the bladder, and 0.63 {+-} 0.16 for the rectum

  6. Inverse anticipating chaos synchronization.

    PubMed

    Shahverdiev, E M; Sivaprakasam, S; Shore, K A

    2002-07-01

    We derive conditions for achieving inverse anticipating synchronization where a driven time-delay chaotic system synchronizes to the inverse future state of the driver. The significance of inverse anticipating chaos in delineating synchronization regimes in time-delay systems is elucidated. The concept is extended to cascaded time-delay systems.

  7. Adaptive Optics and planned HST follow-up observations of the strongly lensed SNIa iPTF16geu

    NASA Astrophysics Data System (ADS)

    Goobar, Ariel; Amanullah, Rahman; Kulkarni, Shri; Steidel, Charles; Law, David

    2016-10-01

    Adaptive optics (AO) observations of iPTF16geu (ATel #9603) were carried out on October 11 with NACO in Natural Guide Star (NGS) mode on VLT. A bright star 30" SE of the SN position provided for the AO corrections.

  8. Providing Adaptation and Guidance for Design Learning by Problem Solving: The Design Planning Approach in DomoSim-TPC Environment

    ERIC Educational Resources Information Center

    Redondo, Miguel A.; Bravo, Crescencio; Ortega, Manuel; Verdejo, M. Felisa

    2007-01-01

    Experimental learning environments based on simulation usually require monitoring and adaptation to the actions the users carry out. Some systems provide this functionality, but they do so in a way which is static or cannot be applied to problem solving tasks. In response to this problem, we propose a method based on the use of intermediate…

  9. An Image-Guided Study of Setup Reproducibility of Postmastectomy Breast Cancer Patients Treated With Inverse-Planned Intensity Modulated Radiation Therapy

    SciTech Connect

    Feng, Christine H.; Gerry, Emily; Chmura, Steven J.; Hasan, Yasmin; Al-Hallaq, Hania A.

    2015-01-01

    Purpose: To calculate planning target volume (PTV) margins for chest wall and regional nodal targets using daily orthogonal kilovolt (kV) imaging and to study residual setup error after kV alignment using volumetric cone-beam computed tomography (CBCT). Methods and Materials: Twenty-one postmastectomy patients were treated with intensity modulated radiation therapy with 7-mm PTV margins. Population-based PTV margins were calculated from translational shifts after daily kV positioning and/or weekly CBCT data for each of 8 patients, whose surgical clips were used as surrogates for target volumes. Errors from kV and CBCT data were mathematically combined to generate PTV margins for 3 simulated alignment workflows: (1) skin marks alone; (2) weekly kV imaging; and (3) daily kV imaging. Results: The kV data from 613 treatment fractions indicated that a 7-mm uniform margin would account for 95% of daily shifts if patients were positioned using only skin marks. Total setup errors incorporating both kV and CBCT data were larger than those from kV alone, yielding PTV expansions of 7 mm anterior–posterior, 9 mm left–right, and 9 mm superior–inferior. Required PTV margins after weekly kV imaging were similar in magnitude as alignment to skin marks, but rotational adjustments of patients were required in 32% ± 17% of treatments. These rotations would have remained uncorrected without the use of daily kV imaging. Despite the use of daily kV imaging, CBCT data taken at the treatment position indicate that an anisotropic PTV margin of 6 mm anterior–posterior, 4 mm left–right, and 8 mm superior–inferior must be retained to account for residual errors. Conclusions: Cone-beam CT provides additional information on 3-dimensional reproducibility of treatment setup for chest wall targets. Three-dimensional data indicate that a uniform 7-mm PTV margin is insufficient in the absence of daily IGRT. Interfraction movement is greater than suggested by 2-dimensional

  10. Adaptive VFH

    NASA Astrophysics Data System (ADS)

    Odriozola, Iñigo; Lazkano, Elena; Sierra, Basi

    2011-10-01

    This paper investigates the improvement of the Vector Field Histogram (VFH) local planning algorithm for mobile robot systems. The Adaptive Vector Field Histogram (AVFH) algorithm has been developed to improve the effectiveness of the traditional VFH path planning algorithm overcoming the side effects of using static parameters. This new algorithm permits the adaptation of planning parameters for the different type of areas in an environment. Genetic Algorithms are used to fit the best VFH parameters to each type of sector and, afterwards, every section in the map is labelled with the sector-type which best represents it. The Player/Stage simulation platform has been chosen for making all sort of tests and to prove the new algorithm's adequateness. Even though there is still much work to be carried out, the developed algorithm showed good navigation properties and turned out to be softer and more effective than the traditional VFH algorithm.

  11. Computers in My Curriculum? 18 Lesson Plans for Teaching Computer Awareness without a Computer. Adaptable Grades 3-12.

    ERIC Educational Resources Information Center

    Bailey, Suzanne Powers; Jeffers, Marcia

    Eighteen interrelated, sequential lesson plans and supporting materials for teaching computer literacy at the elementary and secondary levels are presented. The activities, intended to be infused into the regular curriculum, do not require the use of a computer. The introduction presents background information on computer literacy, suggests a…

  12. An Inversion Recovery NMR Kinetics Experiment

    ERIC Educational Resources Information Center

    Williams, Travis J.; Kershaw, Allan D.; Li, Vincent; Wu, Xinping

    2011-01-01

    A convenient laboratory experiment is described in which NMR magnetization transfer by inversion recovery is used to measure the kinetics and thermochemistry of amide bond rotation. The experiment utilizes Varian spectrometers with the VNMRJ 2.3 software, but can be easily adapted to any NMR platform. The procedures and sample data sets in this…

  13. Evaluation of Online/Offline Image Guidance/Adaptation Approaches for Prostate Cancer Radiation Therapy

    SciTech Connect

    Qin, An; Sun, Ying; Liang, Jian; Yan, Di

    2015-04-01

    Purpose: To evaluate online/offline image-guided/adaptive treatment techniques for prostate cancer radiation therapy with daily cone-beam CT (CBCT) imaging. Methods and Materials: Three treatment techniques were evaluated retrospectively using daily pre- and posttreatment CBCT images on 22 prostate cancer patients. Prostate, seminal vesicles (SV), rectal wall, and bladder were delineated on all CBCT images. For each patient, a pretreatment intensity modulated radiation therapy plan with clinical target volume (CTV) = prostate + SV and planning target volume (PTV) = CTV + 3 mm was created. The 3 treatment techniques were as follows: (1) Daily Correction: The pretreatment intensity modulated radiation therapy plan was delivered after online CBCT imaging, and position correction; (2) Online Planning: Daily online inverse plans with 3-mm CTV-to-PTV margin were created using online CBCT images, and delivered; and (3) Hybrid Adaption: Daily Correction plus an offline adaptive inverse planning performed after the first week of treatment. The adaptive plan was delivered for all remaining 15 fractions. Treatment dose for each technique was constructed using the daily posttreatment CBCT images via deformable image registration. Evaluation was performed using treatment dose distribution in target and critical organs. Results: Treatment equivalent uniform dose (EUD) for the CTV was within [85.6%, 100.8%] of the pretreatment planned target EUD for Daily Correction; [98.7%, 103.0%] for Online Planning; and [99.2%, 103.4%] for Hybrid Adaptation. Eighteen percent of the 22 patients in Daily Correction had a target dose deficiency >5%. For rectal wall, the mean ± SD of the normalized EUD was 102.6% ± 2.7% for Daily Correction, 99.9% ± 2.5% for Online Planning, and 100.6% ± 2.1% for Hybrid Adaptation. The mean ± SD of the normalized bladder EUD was 108.7% ± 8.2% for Daily Correction, 92.7% ± 8.6% for Online Planning, and 89.4% ± 10.8% for Hybrid

  14. Models of reforestation productivity and carbon sequestration for land use and climate change adaptation planning in South Australia.

    PubMed

    Hobbs, Trevor J; Neumann, Craig R; Meyer, Wayne S; Moon, Travis; Bryan, Brett A

    2016-10-01

    Environmental management and regional land use planning has become more complex in recent years as growing world population, climate change, carbon markets and government policies for sustainability have emerged. Reforestation and agroforestry options for environmental benefits, carbon sequestration, economic development and biodiversity conservation are now important considerations of land use planners. New information has been collected and regionally-calibrated models have been developed to facilitate better regional land use planning decisions and counter the limitations of currently available models of reforestation productivity and carbon sequestration. Surveys of above-ground biomass of 264 reforestation sites (132 woodlots, 132 environmental plantings) within the agricultural regions of South Australia were conducted, and combined with spatial information on climate and soils, to develop new spatial and temporal models of plant density and above-ground biomass productivity from reforestation. The models can be used to estimate productivity and total carbon sequestration (i.e. above-ground + below-ground biomass) under a continuous range of planting designs (e.g. variable proportions of trees and shrubs or plant densities), timeframes and future climate scenarios. Representative spatial models (1 ha resolution) for 3 reforestation designs (i.e. woodlots, typical environmental planting, biodiverse environmental plantings) × 3 timeframes (i.e. 25, 45, 65 years) × 4 possible climates (i.e. no change, mild, moderate, severe warming and drying) were generated (i.e. 36 scenarios) for use within land use planning tools. PMID:27372250

  15. Adapting the "managing by walking around" methodology as a leadership strategy to communicate a hospital-wide strategic plan.

    PubMed

    Rubin, Marcie Sara; Stone, Richard K

    2010-01-01

    Metropolitan Hospital Center (MHC) in East Harlem, New York, has undergone significant leadership changes within the past few years, and the current leadership team developed a long-term strategic plan for the organization that it wanted to effectively communicate to all hospital staff. The spread of information is a challenge at MHC, as it is in many hospitals, because of the large number of staff working various shifts, and the inability of staff to leave their units at the same time to attend general staff meetings. Because of the recent success of the hospital's Executive WalkRounds Program and Breakthough Program, which embody principles of the leadership strategy Managing By Walking Around (MBWA), the senior leadership team decided to roll out their new strategic plan in a 2-week series of rounds to each unit/department throughout the hospital during each shift. Utilizing this method, 69 percent of MHC staff attended the rounds, and 88.9 percent of management level staff and 64.5 percent of unionized/labor who participated in the hospital's Employee Satisfaction Survey stated that they understood the hospital's new strategic plan. MHC's successful strategy is easily applicable within other similar settings.

  16. Models of reforestation productivity and carbon sequestration for land use and climate change adaptation planning in South Australia.

    PubMed

    Hobbs, Trevor J; Neumann, Craig R; Meyer, Wayne S; Moon, Travis; Bryan, Brett A

    2016-10-01

    Environmental management and regional land use planning has become more complex in recent years as growing world population, climate change, carbon markets and government policies for sustainability have emerged. Reforestation and agroforestry options for environmental benefits, carbon sequestration, economic development and biodiversity conservation are now important considerations of land use planners. New information has been collected and regionally-calibrated models have been developed to facilitate better regional land use planning decisions and counter the limitations of currently available models of reforestation productivity and carbon sequestration. Surveys of above-ground biomass of 264 reforestation sites (132 woodlots, 132 environmental plantings) within the agricultural regions of South Australia were conducted, and combined with spatial information on climate and soils, to develop new spatial and temporal models of plant density and above-ground biomass productivity from reforestation. The models can be used to estimate productivity and total carbon sequestration (i.e. above-ground + below-ground biomass) under a continuous range of planting designs (e.g. variable proportions of trees and shrubs or plant densities), timeframes and future climate scenarios. Representative spatial models (1 ha resolution) for 3 reforestation designs (i.e. woodlots, typical environmental planting, biodiverse environmental plantings) × 3 timeframes (i.e. 25, 45, 65 years) × 4 possible climates (i.e. no change, mild, moderate, severe warming and drying) were generated (i.e. 36 scenarios) for use within land use planning tools.

  17. Optimal regeneration planning for old-growth forest: addressing scientific uncertainty in endangered species recovery through adaptive management

    USGS Publications Warehouse

    Moore, C.T.; Conroy, M.J.

    2006-01-01

    Stochastic and structural uncertainties about forest dynamics present challenges in the management of ephemeral habitat conditions for endangered forest species. Maintaining critical foraging and breeding habitat for the endangered red-cockaded woodpecker (Picoides borealis) requires an uninterrupted supply of old-growth forest. We constructed and optimized a dynamic forest growth model for the Piedmont National Wildlife Refuge (Georgia, USA) with the objective of perpetuating a maximum stream of old-growth forest habitat. Our model accommodates stochastic disturbances and hardwood succession rates, and uncertainty about model structure. We produced a regeneration policy that was indexed by current forest state and by current weight of evidence among alternative model forms. We used adaptive stochastic dynamic programming, which anticipates that model probabilities, as well as forest states, may change through time, with consequent evolution of the optimal decision for any given forest state. In light of considerable uncertainty about forest dynamics, we analyzed a set of competing models incorporating extreme, but plausible, parameter values. Under any of these models, forest silviculture practices currently recommended for the creation of woodpecker habitat are suboptimal. We endorse fully adaptive approaches to the management of endangered species habitats in which predictive modeling, monitoring, and assessment are tightly linked.

  18. SU-E-T-250: New IMRT Sequencing Strategy: Towards Intra-Fraction Plan Adaptation for the MR-Linac

    SciTech Connect

    Kontaxis, C; Bol, G; Lagendijk, J; Raaymakers, B

    2014-06-01

    Purpose: To develop a new sequencer for IMRT planning that during treatment makes the inclusion of external factors possible and by doing so accounts for intra-fraction anatomy changes. Given a real-time imaging modality that will provide the updated patient anatomy during delivery, this sequencer is able to take these changes into account during the calculation of subsequent segments. Methods: Pencil beams are generated for each beam angle of the treatment and a fluence optimization is performed. The pencil beams, together with the patient anatomy and the above optimal fluence form the input of our algorithm. During each iteration the following steps are performed: A fluence optimization is done and each beam's fluence is then split to discrete intensity levels. Deliverable segments are calculated for each one of these. Each segment's area multiplied by its intensity describes its efficiency. The most efficient segment among all beams is then chosen to deliver a part of the calculated fluence and the dose that will be delivered by this segment is calculated. This delivered dose is then subtracted from the remaining dose. This loop is repeated until 90% of the dose has been delivered and a final segment weight optimization is performed to reach full convergence. Results: This algorithm was tested in several prostate cases yielding results that meet all clinical constraints. Quality assurance was performed on Delta4 and film phantoms for one of these prostate cases and received clinical acceptance after passing both gamma analyses with the 3%/3mm criteria. Conclusion: A new sequencing algorithm was developed to facilitate the needs of intensity modulated treatment. The first results on static anatomy confirm that it can calculate clinical plans equivalent to those of the commercially available planning systems. We are now working towards 100% dose convergence which will allow us to handle anatomy deformations. This work is financially supported by Elekta AB

  19. Adapting the Quebecois method for assessing implementation to the French National Alzheimer Plan 2008–2012: lessons for gerontological services integration

    PubMed Central

    Somme, Dominique; Trouvé, Hélène; Perisset, Catherine; Corvol, Aline; Ankri, Joël; Saint-Jean, Olivier; de Stampa, Matthieu

    2014-01-01

    Introduction Many countries face ageing-related demographic and epidemiological challenges, notably neurodegenerative disorders, due to the multiple care services they require, thereby pleading for a more integrated system of care. The integrated Quebecois method issued from the Programme of Research to Integrate Services for the Maintenance of Autonomy inspired a French pilot experiment and the National Alzheimer Plan 2008–2012. Programme of Research to Integrate Services for the Maintenance of Autonomy method implementation was rated with an evaluation grid adapted to assess its successive degrees of completion. Discussion The approaching end of the president's term led to the method's institutionalization (2011–2012), before the implementation study ended. When the government changed, the study was interrupted. The results extracted from that ‘lost’ study (presented herein) have, nonetheless, ‘found’ some key lessons. Key lessons/conclusion It was possible to implement a Quebecois integrated-care method in France. We describe the lessons and pitfalls encountered in adapting this evaluation tool. This process is necessarily multidisciplinary and requires a test phase. A simple tool for quantitative assessment of integration was obtained. The first assessment of the tool was unsatisfactory but requires further studies. In the meantime, we recommend using mixed methodologies to assess the services integration level. PMID:24959112

  20. A Framework for Effective Use of Hydroclimate Models in Climate-Change Adaptation Planning for Managed Habitats with Limited Hydrologic Response Data

    NASA Astrophysics Data System (ADS)

    Esralew, Rachel A.; Flint, Lorraine; Thorne, James H.; Boynton, Ryan; Flint, Alan

    2016-07-01

    Climate-change adaptation planning for managed wetlands is challenging under uncertain futures when the impact of historic climate variability on wetland response is unquantified. We assessed vulnerability of Modoc National Wildlife Refuge (MNWR) through use of the Basin Characterization Model (BCM) landscape hydrology model, and six global climate models, representing projected wetter and drier conditions. We further developed a conceptual model that provides greater value for water managers by incorporating the BCM outputs into a conceptual framework that links modeled parameters to refuge management outcomes. This framework was used to identify landscape hydrology parameters that reflect refuge sensitivity to changes in (1) climatic water deficit (CWD) and recharge, and (2) the magnitude, timing, and frequency of water inputs. BCM outputs were developed for 1981-2100 to assess changes and forecast the probability of experiencing wet and dry water year types that have historically resulted in challenging conditions for refuge habitat management. We used a Yule's Q skill score to estimate the probability of modeled discharge that best represents historic water year types. CWD increased in all models across 72.3-100 % of the water supply basin by 2100. Earlier timing in discharge, greater cool season discharge, and lesser irrigation season water supply were predicted by most models. Under the worst-case scenario, moderately dry years increased from 10-20 to 40-60 % by 2100. MNWR could adapt by storing additional water during the cool season for later use and prioritizing irrigation of habitats during dry years.

  1. A Framework for Effective Use of Hydroclimate Models in Climate-Change Adaptation Planning for Managed Habitats with Limited Hydrologic Response Data.

    PubMed

    Esralew, Rachel A; Flint, Lorraine; Thorne, James H; Boynton, Ryan; Flint, Alan

    2016-07-01

    Climate-change adaptation planning for managed wetlands is challenging under uncertain futures when the impact of historic climate variability on wetland response is unquantified. We assessed vulnerability of Modoc National Wildlife Refuge (MNWR) through use of the Basin Characterization Model (BCM) landscape hydrology model, and six global climate models, representing projected wetter and drier conditions. We further developed a conceptual model that provides greater value for water managers by incorporating the BCM outputs into a conceptual framework that links modeled parameters to refuge management outcomes. This framework was used to identify landscape hydrology parameters that reflect refuge sensitivity to changes in (1) climatic water deficit (CWD) and recharge, and (2) the magnitude, timing, and frequency of water inputs. BCM outputs were developed for 1981-2100 to assess changes and forecast the probability of experiencing wet and dry water year types that have historically resulted in challenging conditions for refuge habitat management. We used a Yule's Q skill score to estimate the probability of modeled discharge that best represents historic water year types. CWD increased in all models across 72.3-100 % of the water supply basin by 2100. Earlier timing in discharge, greater cool season discharge, and lesser irrigation season water supply were predicted by most models. Under the worst-case scenario, moderately dry years increased from 10-20 to 40-60 % by 2100. MNWR could adapt by storing additional water during the cool season for later use and prioritizing irrigation of habitats during dry years.

  2. A Framework for Effective Use of Hydroclimate Models in Climate-Change Adaptation Planning for Managed Habitats with Limited Hydrologic Response Data.

    PubMed

    Esralew, Rachel A; Flint, Lorraine; Thorne, James H; Boynton, Ryan; Flint, Alan

    2016-07-01

    Climate-change adaptation planning for managed wetlands is challenging under uncertain futures when the impact of historic climate variability on wetland response is unquantified. We assessed vulnerability of Modoc National Wildlife Refuge (MNWR) through use of the Basin Characterization Model (BCM) landscape hydrology model, and six global climate models, representing projected wetter and drier conditions. We further developed a conceptual model that provides greater value for water managers by incorporating the BCM outputs into a conceptual framework that links modeled parameters to refuge management outcomes. This framework was used to identify landscape hydrology parameters that reflect refuge sensitivity to changes in (1) climatic water deficit (CWD) and recharge, and (2) the magnitude, timing, and frequency of water inputs. BCM outputs were developed for 1981-2100 to assess changes and forecast the probability of experiencing wet and dry water year types that have historically resulted in challenging conditions for refuge habitat management. We used a Yule's Q skill score to estimate the probability of modeled discharge that best represents historic water year types. CWD increased in all models across 72.3-100 % of the water supply basin by 2100. Earlier timing in discharge, greater cool season discharge, and lesser irrigation season water supply were predicted by most models. Under the worst-case scenario, moderately dry years increased from 10-20 to 40-60 % by 2100. MNWR could adapt by storing additional water during the cool season for later use and prioritizing irrigation of habitats during dry years. PMID:26141222

  3. Sensorimotor adaptation of point-to-point arm movements after spaceflight: the role of internal representation of gravity force in trajectory planning.

    PubMed

    Gaveau, Jérémie; Paizis, Christos; Berret, Bastien; Pozzo, Thierry; Papaxanthis, Charalambos

    2011-08-01

    After an exposure to weightlessness, the central nervous system operates under new dynamic and sensory contexts. To find optimal solutions for rapid adaptation, cosmonauts have to decide whether parameters from the world or their body have changed and to estimate their properties. Here, we investigated sensorimotor adaptation after a spaceflight of 10 days. Five cosmonauts performed forward point-to-point arm movements in the sagittal plane 40 days before and 24 and 72 h after the spaceflight. We found that, whereas the shape of hand velocity profiles remained unaffected after the spaceflight, hand path curvature significantly increased 1 day after landing and returned to the preflight level on the third day. Control experiments, carried out by 10 subjects under normal gravity conditions, showed that loading the arm with varying loads (from 0.3 to 1.350 kg) did not affect path curvature. Therefore, changes in path curvature after spaceflight cannot be the outcome of a control process based on the subjective feeling that arm inertia was increased. By performing optimal control simulations, we found that arm kinematics after exposure to microgravity corresponded to a planning process that overestimated the gravity level and optimized movements in a hypergravity environment (∼1.4 g). With time and practice, the sensorimotor system was recalibrated to Earth's gravity conditions, and cosmonauts progressively generated accurate estimations of the body state, gravity level, and sensory consequences of the motor commands (72 h). These observations provide novel insights into how the central nervous system evaluates body (inertia) and environmental (gravity) states during sensorimotor adaptation of point-to-point arm movements after an exposure to weightlessness.

  4. Seismic Inversion Methods

    NASA Astrophysics Data System (ADS)

    Jackiewicz, Jason

    2009-09-01

    With the rapid advances in sophisticated solar modeling and the abundance of high-quality solar pulsation data, efficient and robust inversion techniques are crucial for seismic studies. We present some aspects of an efficient Fourier Optimally Localized Averaging (OLA) inversion method with an example applied to time-distance helioseismology.

  5. Seismic Inversion Methods

    SciTech Connect

    Jackiewicz, Jason

    2009-09-16

    With the rapid advances in sophisticated solar modeling and the abundance of high-quality solar pulsation data, efficient and robust inversion techniques are crucial for seismic studies. We present some aspects of an efficient Fourier Optimally Localized Averaging (OLA) inversion method with an example applied to time-distance helioseismology.

  6. A ''Voice Inversion Effect?''

    ERIC Educational Resources Information Center

    Bedard, Catherine; Belin, Pascal

    2004-01-01

    Voice is the carrier of speech but is also an ''auditory face'' rich in information on the speaker's identity and affective state. Three experiments explored the possibility of a ''voice inversion effect,'' by analogy to the classical ''face inversion effect,'' which could support the hypothesis of a voice-specific module. Experiment 1 consisted…

  7. Speaker independent acoustic-to-articulatory inversion

    NASA Astrophysics Data System (ADS)

    Ji, An

    Acoustic-to-articulatory inversion, the determination of articulatory parameters from acoustic signals, is a difficult but important problem for many speech processing applications, such as automatic speech recognition (ASR) and computer aided pronunciation training (CAPT). In recent years, several approaches have been successfully implemented for speaker dependent models with parallel acoustic and kinematic training data. However, in many practical applications inversion is needed for new speakers for whom no articulatory data is available. In order to address this problem, this dissertation introduces a novel speaker adaptation approach called Parallel Reference Speaker Weighting (PRSW), based on parallel acoustic and articulatory Hidden Markov Models (HMM). This approach uses a robust normalized articulatory space and palate referenced articulatory features combined with speaker-weighted adaptation to form an inversion mapping for new speakers that can accurately estimate articulatory trajectories. The proposed PRSW method is evaluated on the newly collected Marquette electromagnetic articulography -- Mandarin Accented English (EMA-MAE) corpus using 20 native English speakers. Cross-speaker inversion results show that given a good selection of reference speakers with consistent acoustic and articulatory patterns, the PRSW approach gives good speaker independent inversion performance even without kinematic training data.

  8. An adaptive approach to metal artifact reduction in helical computed tomography for radiation therapy treatment planning: Experimental and clinical studies

    SciTech Connect

    Yazdia, Mehran; Gingras, Luc; Beaulieu, Luc . E-mail: beaulieu@phy.ulaval.ca

    2005-07-15

    Purpose: In this article, an approach to metal artifact reduction is proposed that is practical for clinical use in radiation therapy. It is based on a new interpolation scheme of the projections associated with metal implants in helical computed tomography (CT) scanners. Methods and Materials: A three-step approach was developed consisting of an automatic algorithm for metal implant detection, a correction algorithm for helical projections, and a new, efficient algorithm for projection interpolation. The modified raw projection data are transferred back to the CT scanner device where CT slices are regenerated using the built-in reconstruction operator. The algorithm was tested on a CT calibration phantom in which the density of inserted objects are known and on clinical prostate cases with two hip prostheses. The results are evaluated using the CT number and shape of the objects. Results: The validations on a CT calibration phantom with various inserts of known densities show that the algorithm improved the overall image quality by restoring the shape and the representative CT number of the objects in the image. For the clinical hip replacement cases, a large fraction of the bladder, rectum, and prostate that were not visible on the original CT slices were recovered using the algorithm. Precise contouring of the target volume was thus feasible. Without this enhancement, physicians would have drawn bigger margins to be sure to include the target and, at the same time, could have prescribed a lower dose to keep the same level of normal tissue toxicity. Conclusions: In both phantom experiment and patient studies, the algorithm resulted in significant artifact reduction with increases in the reliability of planning procedure for the case of metallic hip prostheses. This algorithm is now clinically used as a preprocessing before treatment planning for metal artifact reduction.

  9. Pacific-Australia Climate Change Science and Adaptation Planning program: supporting climate science and enhancing climate services in Pacific Island Countries

    NASA Astrophysics Data System (ADS)

    Kuleshov, Yuriy; Jones, David; Hendon, Harry; Charles, Andrew; Shelton, Kay; de Wit, Roald; Cottrill, Andrew; Nakaegawa, Toshiyuki; Atalifo, Terry; Prakash, Bipendra; Seuseu, Sunny; Kaniaha, Salesa

    2013-04-01

    Over the past few years, significant progress in developing climate science for the Pacific has been achieved through a number of research projects undertaken under the Australian government International Climate Change Adaptation Initiative (ICCAI). Climate change has major impact on Pacific Island Countries and advancement in understanding past, present and futures climate in the region is vital for island nation to develop adaptation strategies to their rapidly changing environment. This new science is now supporting new services for a wide range of stakeholders in the Pacific through the National Meteorological Agencies of the region. Seasonal climate prediction is particularly important for planning in agriculture, tourism and other weather-sensitive industries, with operational services provided by all National Meteorological Services in the region. The interaction between climate variability and climate change, for example during droughts or very warm seasons, means that much of the early impacts of climate change are being felt through seasonal variability. A means to reduce these impacts is to improve forecasts to support decision making. Historically, seasonal climate prediction has been developed based on statistical past relationship. Statistical methods relate meteorological variables (e.g. temperature and rainfall) to indices which describe large-scale environment (e.g. ENSO indices) using historical data. However, with observed climate change, statistical approaches based on historical data are getting less accurate and less reliable. Recognising the value of seasonal forecasts, we have used outputs of a dynamical model POAMA (Predictive Ocean Atmosphere Model for Australia), to develop web-based information tools (http://poama.bom.gov.au/experimental/pasap/index.shtml) which are now used by climate services in 15 partner countries in the Pacific for preparing seasonal climate outlooks. Initial comparison conducted during 2012 has shown that the

  10. Adaptive Image-Guided Radiotherapy (IGRT) Eliminates the Risk of Biochemical Failure Caused by the Bias of Rectal Distension in Prostate Cancer Treatment Planning: Clinical Evidence

    SciTech Connect

    Park, Sean S.; Yan Di; McGrath, Samuel; Dilworth, Joshua T.; Liang Jian; Ye Hong; Krauss, Daniel J.; Martinez, Alvaro A.; Kestin, Larry L.

    2012-07-01

    Purpose: Rectal distension has been shown to decrease the probability of biochemical control. Adaptive image-guided radiotherapy (IGRT) corrects for target position and volume variations, reducing the risk of biochemical failure while yielding acceptable rates of gastrointestinal (GI)/genitourinary (GU) toxicities. Methods and Materials: Between 1998 and 2006, 962 patients were treated with computed tomography (CT)-based offline adaptive IGRT. Patients were stratified into low (n = 400) vs. intermediate/high (n = 562) National Comprehensive Cancer Network (NCCN) risk groups. Target motion was assessed with daily CT during the first week. Electronic portal imaging device (EPID) was used to measure daily setup error. Patient-specific confidence-limited planning target volumes (cl-PTV) were then constructed, reducing the standard PTV and compensating for geometric variation of the target and setup errors. Rectal volume (RV), cross-sectional area (CSA), and rectal volume from the seminal vesicles to the inferior prostate (SVP) were assessed on the planning CT. The impact of these volumetric parameters on 5-year biochemical control (BC) and chronic Grades {>=}2 and 3 GU and GI toxicity were examined. Results: Median follow-up was 5.5 years. Median minimum dose covering cl-PTV was 75.6 Gy. Median values for RV, CSA, and SVP were 82.8 cm{sup 3}, 5.6 cm{sup 2}, and 53.3 cm{sup 3}, respectively. The 5-year BC was 89% for the entire group: 96% for low risk and 83% for intermediate/high risk (p < 0.001). No statistically significant differences in BC were seen with stratification by RV, CSA, and SVP in quartiles. Maximum chronic Grades {>=}2 and 3 GI toxicities were 21.2% and 2.9%, respectively. Respective values for GU toxicities were 15.5% and 4.3%. No differences in GI or GU toxicities were noted when patients were stratified by RV. Conclusions: Incorporation of adaptive IGRT reduces the risk of geometric miss and results in excellent biochemical control that is

  11. Backstepping-based cooperative and adaptive tracking control design for a group of underactuated AUVs in horizontal plan

    NASA Astrophysics Data System (ADS)

    Ghommam, Jawhar; Saad, Maarouf

    2014-05-01

    In this paper, we investigate new implementable cooperative adaptive backstepping controllers for a group of underactuated autonomous vehicles that are communicating with their local neighbours to track a time-varying virtual leader of which the relative position may only be available to a portion of the team members. At the kinematic cooperative control level of the autonomous underwater vehicle, the virtual cooperative controller is basically designed on a proportional and derivative consensus algorithm presented in Ren (2010), which involves velocity information from local neighbours. In this paper, we propose a new design algorithm based on singular perturbation theory that precludes the use of the neighbours' velocity information in the cooperative design. At the dynamic cooperative control level, calculation of the partial derivatives of some stabilising functions which in turn will contain velocity information from the local neighbours is required. To facilitate the implementation of the cooperative controllers, we propose a command filter approach technique to avoid analytic differentiation of the virtual cooperative control laws. We show how Lyapunov-based techniques and graph theory can be combined together to yield a robust cooperative controller where the uncertain dynamics of the cooperating vehicles and the constraints on the communication topology which contains a directed spanning tree are explicitly taken into account. Simulation results with a dynamic model of underactuated autonomous underwater vehicles moving on the horizontal plane are presented and discussed.

  12. Effects of spatial pattern of green space on land surface temperature: implications for sustainable urban planning and climate change adaptation

    NASA Astrophysics Data System (ADS)

    Maimaitiyiming, M.; Ghulam, A.

    2013-12-01

    The urban heat island (UHI) refers to the phenomenon of higher atmospheric and surface temperatures occurring in urban areas than in the surrounding rural areas. Numerous studies have shown that increased percent cover of green space (PLAND) can significantly decrease land surface temperatures (LST). Fewer studies, however, have investigated the effects of configuration of green space on LST. This paper aims at to fill this gap using oasis city Aksu in northwestern China as a case study. PLAND along with two configuration metrics are used to measure the composition and configuration of green space. The metrics are calculated by moving window method based on a green space map derived from Landsat Thematic Mapper (TM) imagery, and LST data are retrieved from Landsat TM thermal band. Normalized mutual information measure is employed to investigate the relationship between LST and the spatial pattern of green space. The results show that while the PLAND is the most important variable that elicits LST dynamics, spatial configuration of green space also has significant effect on LST. In addition, the variance of LST is largely explained by both composition and configuration of green space. Results from this study can expand our understanding of the relationship between LST and vegetation, and provide insights for sustainable urban planning and management under changing climate.

  13. An emerging crisis across northern prairie refuges: Prevalence of invasive plants and a plan for adaptive management

    USGS Publications Warehouse

    Grant, T.A.; Flanders-Wanner, B.; Shaffer, T.L.; Murphy, R.K.; Knutsen, G.A.

    2009-01-01

    In the northern Great Plains, native prairies managed by the U.S. Fish and Wildlife Service (Service) can be pivotal in conservation of North America's biological diversity. From 2002 to 2006, we surveyed 7,338 belt transects to assess the general composition of mixed-grass and tallgrass prairie vegetation across five "complexes" (i.e., administrative groupings) of national wildlife refuges managed by the Service in North Dakota and South Dakota. Native grasses and forbs were common (mean frequency of occurrence 47%-54%) on two complexes but uncommon (4%-13%) on two others. Conversely, an introduced species of grass, smooth brome (Bromus inermis), accounted for 45% to 49% of vegetation on two complexes and another species, Kentucky bluegrass (Poa pratensis) accounted for 27% to 36% of the vegetation on three of the complexes. Our data confirm prior suspicions of widespread invasion by introduced species of plants on Service-owned tracts of native prairie, changes that likely stem in part from a common management history of little or no disturbance (e.g., defoliation by grazing or fire). However, variability in the degree and type of invasion among prairie tracts suggests that knowledge of underlying causes (e.g., edaphic or climatic factors, management histories) could help managers more effectively restore prairies. We describe an adaptive management approach to acquire such knowledge while progressing with restoration. More specifically, we propose to use data from inventories of plant communities on Service-owned prairies to design and implement, as experiments, optimal restoration strategies. We will then monitor these experiments and use the results to refine future strategies. This comprehensive, process-oriented approach should yield reliable and robust recommendations for restoration and maintenance of native prairies in the northern Great Plains. ??2009 by the Board of Regents of the University of Wisconsin System.

  14. Adaptive control of robotic manipulators

    NASA Technical Reports Server (NTRS)

    Seraji, H.

    1987-01-01

    The author presents a novel approach to adaptive control of manipulators to achieve trajectory tracking by the joint angles. The central concept in this approach is the utilization of the manipulator inverse as a feedforward controller. The desired trajectory is applied as an input to the feedforward controller which behaves as the inverse of the manipulator at any operating point; the controller output is used as the driving torque for the manipulator. The controller gains are then updated by an adaptation algorithm derived from MRAC (model reference adaptive control) theory to cope with variations in the manipulator inverse due to changes of the operating point. An adaptive feedback controller and an auxiliary signal are also used to enhance closed-loop stability and to achieve faster adaptation. The proposed control scheme is computationally fast and does not require a priori knowledge of the complex dynamic model or the parameter values of the manipulator or the payload.

  15. Interactive Genetic Algorithm - An Adaptive and Interactive Decision Support Framework for Design of Optimal Groundwater Monitoring Plans

    NASA Astrophysics Data System (ADS)

    Babbar-Sebens, M.; Minsker, B. S.

    2006-12-01

    that met the DM's preference criteria, therefore allowing the expert to select among several strong candidate designs depending on her/his LTM budget, c) two of the methodologies - Case-Based Micro Interactive Genetic Algorithm (CBMIGA) and Interactive Genetic Algorithm with Mixed Initiative Interaction (IGAMII) - were also able to assist in controlling human fatigue and adapt to the DM's learning process.

  16. Solar inverse theory

    NASA Astrophysics Data System (ADS)

    Gough, D.

    1984-12-01

    Helioseismological inversion, as with the inversion of any other data, is divided into three phases. The first is the solution of the so-called forward problem: namely, the calculation of the eigenfrequencies of a theoretical equilibrium state. The second is an attempt to understand the results, either empirically by determining how those frequencies vary as chosen parameters defining the equilibrium model are varied, or analytically from asymptotic expansions in limiting cases of high order or degree. The third phase is to pose and solve an inverse problem, which seeks to find a plausible equilibrium model of the Sun whose eigenfrequencies are consistent with observation. The three phases are briefly discussed in this review, and the third, which is not yet widely used in helioseismology, is illustrated with some selected inversions of artificial solar data.

  17. Modeled Sea Level Rise Impacts on Coastal Ecosystems at Six Major Estuaries on Florida’s Gulf Coast: Implications for Adaptation Planning

    PubMed Central

    Birch, Anne P.; Brenner, Jorge; Gordon, Doria R.

    2015-01-01

    The Sea Level Affecting Marshes Model (SLAMM) was applied at six major estuaries along Florida’s Gulf Coast (Pensacola Bay, St. Andrews/Choctawhatchee Bays, Apalachicola Bay, Southern Big Bend, Tampa Bay and Charlotte Harbor) to provide quantitative and spatial information on how coastal ecosystems may change with sea level rise (SLR) and to identify how this information can be used to inform adaption planning. High resolution LiDAR-derived elevation data was utilized under three SLR scenarios: 0.7 m, 1 m and 2 m through the year 2100 and uncertainty analyses were conducted on selected input parameters at three sites. Results indicate that the extent, spatial orientation and relative composition of coastal ecosystems at the study areas may substantially change with SLR. Under the 1 m SLR scenario, total predicted impacts for all study areas indicate that coastal forest (-69,308 ha; -18%), undeveloped dry land (-28,444 ha; -2%) and tidal flat (-25,556 ha; -47%) will likely face the greatest loss in cover by the year 2100. The largest potential gains in cover were predicted for saltmarsh (+32,922 ha; +88%), transitional saltmarsh (+23,645 ha; na) and mangrove forest (+12,583 ha; +40%). The Charlotte Harbor and Tampa Bay study areas were predicted to experience the greatest net loss in coastal wetlands The uncertainty analyses revealed low to moderate changes in results when some numerical SLAMM input parameters were varied highlighting the value of collecting long-term sedimentation, accretion and erosion data to improve SLAMM precision. The changes predicted by SLAMM will affect exposure of adjacent human communities to coastal hazards and ecosystem functions potentially resulting in impacts to property values, infrastructure investment and insurance rates. The results and process presented here can be used as a guide for communities vulnerable to SLR to identify and prioritize adaptation strategies that slow and/or accommodate the changes underway. PMID:26207914

  18. Generalized emissivity inverse problem.

    PubMed

    Ming, DengMing; Wen, Tao; Dai, XianXi; Dai, JiXin; Evenson, William E

    2002-04-01

    Inverse problems have recently drawn considerable attention from the physics community due to of potential widespread applications [K. Chadan and P. C. Sabatier, Inverse Problems in Quantum Scattering Theory, 2nd ed. (Springer Verlag, Berlin, 1989)]. An inverse emissivity problem that determines the emissivity g(nu) from measurements of only the total radiated power J(T) has recently been studied [Tao Wen, DengMing Ming, Xianxi Dai, Jixin Dai, and William E. Evenson, Phys. Rev. E 63, 045601(R) (2001)]. In this paper, a new type of generalized emissivity and transmissivity inverse (GETI) problem is proposed. The present problem differs from our previous work on inverse problems by allowing the unknown (emissivity) function g(nu) to be temperature dependent as well as frequency dependent. Based on published experimental information, we have developed an exact solution formula for this GETI problem. A universal function set suggested for numerical calculation is shown to be robust, making this inversion method practical and convenient for realistic calculations.

  19. The inverse electroencephalography pipeline

    NASA Astrophysics Data System (ADS)

    Weinstein, David Michael

    The inverse electroencephalography (EEG) problem is defined as determining which regions of the brain are active based on remote measurements recorded with scalp EEG electrodes. An accurate solution to this problem would benefit both fundamental neuroscience research and clinical neuroscience applications. However, constructing accurate patient-specific inverse EEG solutions requires complex modeling, simulation, and visualization algorithms, and to date only a few systems have been developed that provide such capabilities. In this dissertation, a computational system for generating and investigating patient-specific inverse EEG solutions is introduced, and the requirements for each stage of this Inverse EEG Pipeline are defined and discussed. While the requirements of many of the stages are satisfied with existing algorithms, others have motivated research into novel modeling and simulation methods. The principal technical results of this work include novel surface-based volume modeling techniques, an efficient construction for the EEG lead field, and the Open Source release of the Inverse EEG Pipeline software for use by the bioelectric field research community. In this work, the Inverse EEG Pipeline is applied to three research problems in neurology: comparing focal and distributed source imaging algorithms; separating measurements into independent activation components for multifocal epilepsy; and localizing the cortical activity that produces the P300 effect in schizophrenia.

  20. Direct and indirect inversions

    NASA Astrophysics Data System (ADS)

    Virieux, Jean; Brossier, Romain; Métivier, Ludovic; Operto, Stéphane; Ribodetti, Alessandra

    2016-06-01

    A bridge is highlighted between the direct inversion and the indirect inversion. They are based on fundamental different approaches: one is looking after a projection from the data space to the model space while the other one is reducing a misfit between observed data and synthetic data obtained from a given model. However, it is possible to obtain similar structures for model perturbation, and we shall focus on P-wave velocity reconstruction. This bridge is built up through the Born approximation linearizing the forward problem with respect to model perturbation and through asymptotic approximations of the Green functions of the wave propagation equation. We first describe the direct inversion and its ingredients and then we focus on a specific misfit function design leading to a indirect inversion. Finally, we shall compare this indirect inversion with more standard least-squares inversion as the FWI, enabling the focus on small weak velocity perturbations on one side and the speed-up of the velocity perturbation reconstruction on the other side. This bridge has been proposed by the group led by Raul Madariaga in the early nineties, emphasizing his leading role in efficient imaging workflows for seismic velocity reconstruction, a drastic requirement at that time.

  1. SU-E-J-77: Dose Tracking On An MR-Linac for Online QA and Plan Adaptation in Abdominal Organs

    SciTech Connect

    Glitzner, M; Crijns, S; Kontaxis, C; Prins, F; Lagendijk, J; Raaymakers, B; Senneville, B Denis de

    2015-06-15

    Recent developments made MRI-guided radiotherapy feasible. Simultaneously performed imaging during dose delivery reveals the influence of changes in anatomy not yet known at the planning stage. When targeting highly motile abdominal organs, respiratory gating is commonly employed in MRI and investigated in external beam radiotherapy to mitigate malicious motion effects. The purpose of the presented work is to investigate anatomy-adaptive dose reconstruction in the treatment of abdominalorgans using concurrent (duplex) gating of an integrated MRlinac modality.Using navigators, 3D-MR images were sampled during exhale phase, requiring 3s per axial volume (360×260×100mm{sup 3}, waterselective T1w-FFE). Deformation vector fields (DVF) were calculated for all imaging dynamics with respect to initial anatomy, yielding an estimation of anatomy changes over the time of a fraction. A pseudo-CT was generated from the outline of a reference MR image, assuming a water-filled body. Consecutively, a treatment was planned on a fictional kidney lesion and optimized simulating a 6MV linac in a 1.5T magnetic field. After delivery, using the DVF, the pseudo-CT was deformed and dose accumulated for every individual gating interval yielding the true accumulated dose on the dynamic anatomy during beam-on.Dose-volume parameters on the PTV show only moderate changes when incorporating motion, i.e. ΔD{sub 99} (GTV)=0.3Gy with D{sub 99} (GTV)=20Gy constraints. However, local differences in the PTV region showed underdosages as high as 2.7Gy and overdosages up to 1.4Gy as compared to the optimized dose on static anatomy.A dose reconstruction toolchain was successfully implemented and proved its potential in the duplex gated treatment of abdominal organs by means of an MR-linac modality. While primary dose constraints were not violated on the fictional test data, large deviations could be found locally, which are left unaccounted for in conventional treatments. Dose-tracking of both target

  2. MASSACHUSETTS DIVISION OF FISHERIES AND WILDLIFE ADAPTATION PLANNING USING AN EXPERT PANEL BASED HABITAT VULNERABLITY ASSESSMENT John O'Leary, MA Div. of Fisheries and Wildlife and Hector Galbraith, Ph d. Climate Change Initiative, Manomet Center for Conservation Sciences

    NASA Astrophysics Data System (ADS)

    O'Leary, J. A.; Galbraith, H.

    2010-12-01

    We are using the results from a recently completed Habitat Vulnerability Assessment (HVA) for adaptation planning within the Massachusetts Division of Fisheries and Wildlife. We used Regional Downscale Climate Projections to provide exposure information for the assessment and an Expert Panel of biologists to provide information on the sensitivity and adaptive capacity of the habitat types we assessed. We estimated the vulnerability of 22 key habitat types which were identified in the State Wildlife Action Plan (SWAP). Results of the expert panel based HVA include a relative ranking of vulnerability to climate change for these habitats within Massachusetts, a confidence score for the estimated vulnerability for each habitat type evaluated and a narrative identifying the factors which influence the vulnerability of the habitat. We also evaluated the vulnerability of the Species in Greatest Conservation Need (SGCN) from the SWAP to climate change conditions. The SGCN are linked to their primary habitat types. The HVA results along with recommendations from the National Academies Report: Adapting to the Impacts of Climate Change America’s Climate Choices: Panel on Adapting to the Impacts of Climate Change will inform “climate smart” adaptation strategies for agency management, acquisition, and research and monitoring programs that build on and do not replace existing implementation strategies. We believe that the adaptation planning process that we outline in this presentation could serve as a model for resource agencies and others who are in the process of developing their response to anticipated impacts from climate change conditions. We are also engaged in a collaborative effort to conduct a Regional Habitat Vulnerability Assessment (RHVA). Results form the RHVA will provide the MDFW with the ability to assess adaptation strategies based on regional need.

  3. Aquifer Structure Identification Using Stochastic Inversion

    SciTech Connect

    Harp, Dylan R; Dai, Zhenxue; Wolfsberg, Andrew V; Vrugt, Jasper A

    2008-01-01

    This study presents a stochastic inverse method for aquifer structure identification using sparse geophysical and hydraulic response data. The method is based on updating structure parameters from a transition probability model to iteratively modify the aquifer structure and parameter zonation. The method is extended to the adaptive parameterization of facies hydraulic parameters by including these parameters as optimization variables. The stochastic nature of the statistical structure parameters leads to nonconvex objective functions. A multi-method genetically adaptive evolutionary approach (AMALGAM-SO) was selected to perform the inversion given its search capabilities. Results are obtained as a probabilistic assessment of facies distribution based on indicator cokriging simulation of the optimized structural parameters. The method is illustrated by estimating the structure and facies hydraulic parameters of a synthetic example with a transient hydraulic response.

  4. Analysis of Temperature Distributions in Nighttime Inversions

    NASA Astrophysics Data System (ADS)

    Telyak, Oksana; Krasouski, Aliaksandr; Svetashev, Alexander; Turishev, Leonid; Barodka, Siarhei

    2015-04-01

    theoretical approaches based on discriminant analysis, mesoscale modeling with WRF provides fairly successful forecasts of formation times and regions for all types of temperature inversions up to 3 days in advance. Furthermore, we conclude that without proper adjustment for the presence of thin isothermal layers (adiabatic and/or inversion layers), temperature data can affect results of statistical climate studies. Provided there are regions where a long-term, constant inversion is present (e.g., Antarctica or regions with continental climate), these data can contribute an uncompensated systematic error of 2 to 10° C. We argue that this very fact may lead to inconsistencies in long-term temperature data interpretations (e.g., conclusions ranging from "global warming" to "global cooling" based on temperature observations for the same region and time period). Due to the importance of this problem from the scientific as well as practical point of view, our plans for further studies include analysis of autumn and wintertime inversions and convective inversions. At the same time, it seems promising to develop an algorithm of automatic recognition of temperature inversions based on a combination of WRF modeling results, surface and satellite observations.

  5. Boundary conditions of patient-specific fluid dynamics modelling of cavopulmonary connections: possible adaptation of pulmonary resistances results in a critical issue for a virtual surgical planning

    PubMed Central

    Pennati, Giancarlo; Corsini, Chiara; Cosentino, Daria; Hsia, Tain-Yen; Luisi, Vincenzo S.; Dubini, Gabriele; Migliavacca, Francesco

    2011-01-01

    Cavopulmonary connections are surgical procedures used to treat a variety of complex congenital cardiac defects. Virtual pre-operative planning based on in silico patient-specific modelling might become a powerful tool in the surgical decision-making process. For this purpose, three-dimensional models can be easily developed from medical imaging data to investigate individual haemodynamics. However, the definition of patient-specific boundary conditions is still a crucial issue. The present study describes an approach to evaluate the vascular impedance of the right and left lungs on the basis of pre-operative clinical data and numerical simulations. Computational fluid dynamics techniques are applied to a patient with a bidirectional cavopulmonary anastomosis, who later underwent a total cavopulmonary connection (TCPC). Multi-scale models describing the surgical region and the lungs are adopted, while the flow rates measured in the venae cavae are used at the model inlets. Pre-operative and post-operative conditions are investigated; namely, TCPC haemodynamics, which are predicted using patient-specific pre-operative boundary conditions, indicates that the pre-operative balanced lung resistances are not compatible with the TCPC measured flows, suggesting that the pulmonary vascular impedances changed individually after the surgery. These modifications might be the consequence of adaptation to the altered pulmonary blood flows. PMID:22670201

  6. WE-A-17A-06: Evaluation of An Automatic Interstitial Catheter Digitization Algorithm That Reduces Treatment Planning Time and Provide Means for Adaptive Re-Planning in HDR Brachytherapy of Gynecologic Cancers

    SciTech Connect

    Dise, J; Liang, X; Lin, L; Teo, B

    2014-06-15

    Purpose: To evaluate an automatic interstitial catheter digitization algorithm that reduces treatment planning time and provide means for adaptive re-planning in HDR Brachytherapy of Gynecologic Cancers. Methods: The semi-automatic catheter digitization tool utilizes a region growing algorithm in conjunction with a spline model of the catheters. The CT images were first pre-processed to enhance the contrast between the catheters and soft tissue. Several seed locations were selected in each catheter for the region growing algorithm. The spline model of the catheters assisted in the region growing by preventing inter-catheter cross-over caused by air or metal artifacts. Source dwell positions from day one CT scans were applied to subsequent CTs and forward calculated using the automatically digitized catheter positions. This method was applied to 10 patients who had received HDR interstitial brachytherapy on an IRB approved image-guided radiation therapy protocol. The prescribed dose was 18.75 or 20 Gy delivered in 5 fractions, twice daily, over 3 consecutive days. Dosimetric comparisons were made between automatic and manual digitization on day two CTs. Results: The region growing algorithm, assisted by the spline model of the catheters, was able to digitize all catheters. The difference between automatic and manually digitized positions was 0.8±0.3 mm. The digitization time ranged from 34 minutes to 43 minutes with a mean digitization time of 37 minutes. The bulk of the time was spent on manual selection of initial seed positions and spline parameter adjustments. There was no significance difference in dosimetric parameters between the automatic and manually digitized plans. D90% to the CTV was 91.5±4.4% for the manual digitization versus 91.4±4.4% for the automatic digitization (p=0.56). Conclusion: A region growing algorithm was developed to semi-automatically digitize interstitial catheters in HDR brachytherapy using the Syed-Neblett template. This automatic

  7. An adaptive dual-optimal path-planning technique for unmanned air vehicles with application to solar-regenerative high altitude long endurance flight

    NASA Astrophysics Data System (ADS)

    Whitfield, Clifford A.

    2009-12-01

    A multi-objective technique for Unmanned Air Vehicle (UAV) path and trajectory autonomy generation, through task allocation and sensor fusion has been developed. The Dual-Optimal Path-Planning (D-O.P-P.) Technique generates on-line adaptive flight paths for UAVs based on available flight windows and environmental influenced objectives. The environmental influenced optimal condition, known as the driver' determines the condition, within a downstream virtual window of possible vehicle destinations and orientation built from the UAV kinematics. The intermittent results are pursued by a dynamic optimization technique to determine the flight path. This sequential optimization technique is a multi-objective optimization procedure consisting of two goals, without requiring additional information to combine the conflicting objectives into a single-objective. An example case-study and additional applications are developed and the results are discussed; including the application to the field of Solar Regenerative (SR) High Altitude Long Endurance (HALE) UAV flight. Harnessing solar energy has recently been adapted for use on high altitude UAV platforms. An aircraft that uses solar panels and powered by the sun during the day and through the night by SR systems, in principle could sustain flight for weeks or months. The requirements and limitations of solar powered flight were determined. The SR-HALE UAV platform geometry and flight characteristics were selected from an existing aircraft that has demonstrated the capability for sustained flight through flight tests. The goals were to maintain continual Situational Awareness (SA) over a case-study selected Area of Interest (AOI) and existing UAV power and surveillance systems. This was done for still wind and constant wind conditions at altitude along with variations in latitude. The characteristics of solar flux and the dependence on the surface location and orientation were established along with fixed flight maneuvers for

  8. Inversion of triton moments

    NASA Astrophysics Data System (ADS)

    Clare, R. B.; Levinger, J. S.

    1981-02-01

    We use the formalism of hyperspherical harmonics to calculate several moments for the triton photoeffect, for a Volkov spin-independent potential. First, we improve the accuracy of Maleki's calculations of the moments σ2 and σ3 by including more terms in the hyperspherical expansion. We also calculate moments σ0 and σ1 for a Serber mixture. We find reasonable agreement between our moments found by sum rules and those found from the cross sections calculated by Fang et al. and Levinger-Fitzgibbon. We then develop a technique of inversion of a finite number of moments by making the assumption that the cross section can be written as a sum of several Laguerre polynomials multiplied by a decreasing exponential. We test our inversion technique successfully on several model potentials. We then modify it and apply it to the five moments (σ-1 to σ3) for a force without exchange, and find fair agreement with Fang's values of the cross section. Finally, we apply the inversion technique to our three moments (σ-1,σ0,and σ1) for a Serber mixture, and find reasonable agreement with Gorbunov's measurements of the 3He photoeffect. NUCLEAR REACTIONS Triton photoeffects, hyperspherical harmonics, moments of photoeffect, inversion of moments.

  9. Mega drought in the Colorado River Basin, water supply, and adaptive scenario planning for the Phoenix Metropolitan Area; simulations using WaterSim 5.

    NASA Astrophysics Data System (ADS)

    Sampson, D. A.

    2015-12-01

    The Decision Center for a Desert City (DCDC), a boundary organization, bridges science and policy (to foster knowledge-based decision making); we study how decisions are made in the face of uncertainty. Our water policy and management model for the Phoenix Metropolitan Area (hereafter "Phoenix"), termed WaterSim, represents one such bridging mechanism. We evaluated the effect of varying the length of drought on water availability for Phoenix. We examined droughts (starting in 2000) lasting 15, 25, and 50 years. We picked a 60-year window of runoff estimates from the paleo reconstruction data for the Colorado River (CO) (1121 through 1180 A.D.), and the two local rivers (1391 through 1450 A.D.), and assumed that the proportional difference in median flow between these periods and the long-term record represented an estimate of potential drought reductions on river flows. This resulted in a 12%, and 19% reduction in flows for the CO River and the Salt-Verde (SV) Rivers, respectively. WaterSim uses 30-year trace periods from the historical flow records to simulate river flow for future projections. We used each 30-year trace from the historical record (1906 to present, CO River; 1945 to present SV Rivers) , and default settings, to simulate 60 year projections of Lake Mead elevation and the accompanying Colorado River water shortages to Phoenix. Overall, elevations for Lake Mead fell below the 1st shortage sharing tier (1075 ft) in 83% of the simulations; 74% of the simulations fell below the 2nd tier (1050 ft), and 64% fell below the 3rd (1025 ft). Length of drought, however, determined the shortage tiers met. Median elevations for droughts ending in 2015, 2025, and 2050 were 1036, 1019, and 967 feet msl, respectively. We present the plausible water futures with adaptive anticipatory scenario planning for the projected reductions in surface water availability to demonstrate decision points for water conservation measures to effectively manage shortage conditions.

  10. Application of full-wave inversion to real crosshole data

    SciTech Connect

    Song, Z.; Williamson, P.R.

    1994-12-31

    A 2.5D acoustic frequency domain fullwave inversion method was applied to a real dataset from an open-cast coal exploration site. The only data processing required was the removal of tube waves, because no shear wave arrivals were observed. The inversion is efficient because only a few frequency components are needed. The authors encounter two site-specific problems (source inconsistency and anisotropy) which are addressed by simple adaptations of the inversion algorithm. High resolution results are achieved for both velocity and attenuation reconstructions. The fullwave inversion method combines the advantages of first-arrival travel-time tomography and reflected waves migration. To evaluate the inversion result, they model time domain traces using a source signature estimated by fitting the frequency domain response of the reconstructed model to the observed data across the spectrum. The synthetic traces match the early arrivals in the real data reasonably well.

  11. Phase and amplitude inversion of crosswell radar data

    USGS Publications Warehouse

    Ellefsen, Karl J.; Mazzella, Aldo T.; Horton, Robert J.; McKenna, Jason R.

    2011-01-01

    Phase and amplitude inversion of crosswell radar data estimates the logarithm of complex slowness for a 2.5D heterogeneous model. The inversion is formulated in the frequency domain using the vector Helmholtz equation. The objective function is minimized using a back-propagation method that is suitable for a 2.5D model and that accounts for the near-, intermediate-, and far-field regions of the antennas. The inversion is tested with crosswell radar data collected in a laboratory tank. The model anomalies are consistent with the known heterogeneity in the tank; the model’s relative dielectric permittivity, which is calculated from the real part of the estimated complex slowness, is consistent with independent laboratory measurements. The methodologies developed for this inversion can be adapted readily to inversions of seismic data (e.g., crosswell seismic and vertical seismic profiling data).

  12. Population genomics of inversion polymorphisms in Drosophila melanogaster.

    PubMed

    Corbett-Detig, Russell B; Hartl, Daniel L

    2012-01-01

    Chromosomal inversions have been an enduring interest of population geneticists since their discovery in Drosophila melanogaster. Numerous lines of evidence suggest powerful selective pressures govern the distributions of polymorphic inversions, and these observations have spurred the development of many explanatory models. However, due to a paucity of nucleotide data, little progress has been made towards investigating selective hypotheses or towards inferring the genealogical histories of inversions, which can inform models of inversion evolution and suggest selective mechanisms. Here, we utilize population genomic data to address persisting gaps in our knowledge of D. melanogaster's inversions. We develop a method, termed Reference-Assisted Reassembly, to assemble unbiased, highly accurate sequences near inversion breakpoints, which we use to estimate the age and the geographic origins of polymorphic inversions. We find that inversions are young, and most are African in origin, which is consistent with the demography of the species. The data suggest that inversions interact with polymorphism not only in breakpoint regions but also chromosome-wide. Inversions remain differentiated at low levels from standard haplotypes even in regions that are distant from breakpoints. Although genetic exchange appears fairly extensive, we identify numerous regions that are qualitatively consistent with selective hypotheses. Finally, we show that In(1)Be, which we estimate to be ∼60 years old (95% CI 5.9 to 372.8 years), has likely achieved high frequency via sex-ratio segregation distortion in males. With deeper sampling, it will be possible to build on our inferences of inversion histories to rigorously test selective models-particularly those that postulate that inversions achieve a selective advantage through the maintenance of co-adapted allele complexes.

  13. AVO inversion based on inverse operator estimation in trust region

    NASA Astrophysics Data System (ADS)

    Yin, Xing-Yao; Deng, Wei; Zong, Zhao-Yun

    2016-04-01

    Amplitude variation with offset (AVO) inversion is widely utilized in exploration geophysics, especially for reservoir prediction and fluid identification. Inverse operator estimation in the trust region algorithm is applied for solving AVO inversion problems in which optimization and inversion directly are integrated. The L1 norm constraint is considered on the basis of reasonable initial model in order to improve effciency and stability during the AVO inversion process. In this study, high-order Zoeppritz approximation is utilized to establish the inversion objective function in which variation of {{v}\\text{p}}/{{v}\\text{s}} with time is taken into consideration. A model test indicates that the algorithm has a relatively higher stability and accuracy than the damp least-squares algorithm. Seismic data inversion is feasible and inversion values of three parameters ({{v}\\text{p}},{{v}\\text{s}},ρ ) maintain good consistency with logging curves.

  14. Inverse heat conduction problems

    NASA Astrophysics Data System (ADS)

    Orlande, Helcio Rangel Barreto

    We present the solution of the following inverse problems: (1) Inverse Problem of Estimating Interface Conductance Between Periodically Contacting Surfaces; (2) Inverse Problem of Estimating Interface Conductance During Solidification via Conjugate Gradient Method; (3) Determination of the Reaction Function in a Reaction-Diffusion Parabolic Problem; and (4) Simultaneous Estimation of Thermal Diffusivity and Relaxation Time with Hyperbolic Heat Conduction Model. Also, we present the solution of a direct problem entitled: Transient Thermal Constriction Resistance in a Finite Heat Flux Tube. The Conjugate Gradient Method with Adjoint Equation was used in chapters 1-3. The more general function estimation approach was treated in these chapters. In chapter 1, we solve the inverse problem of estimating the timewise variation of the interface conductance between periodically contacting solids, under quasi-steady-state conditions. The present method is found to be more accurate than the B-Spline approach for situations involving small periods, which are the most difficult on which to perform the inverse analysis. In chapter 2, we estimate the timewise variation of the interface conductance between casting and mold during the solidification of aluminum. The experimental apparatus used in this study is described. In chapter 3, we present the estimation of the reaction function in a one dimensional parabolic problem. A comparison of the present function estimation approach with the parameter estimation technique, wing B-Splines to approximate the reaction function, revealed that the use of function estimation reduces the computer time requirements. In chapter 4 we present a finite difference solution for the transient constriction resistance in a cylinder of finite length with a circular contact surface. A numerical grid generation scheme was used to concentrate grid points in the regions of high temperature gradients in order to reduce discretization errors. In chapter 6, we

  15. Unstructured discontinuous Galerkin for seismic inversion.

    SciTech Connect

    van Bloemen Waanders, Bart Gustaaf; Ober, Curtis Curry; Collis, Samuel Scott

    2010-04-01

    This abstract explores the potential advantages of discontinuous Galerkin (DG) methods for the time-domain inversion of media parameters within the earth's interior. In particular, DG methods enable local polynomial refinement to better capture localized geological features within an area of interest while also allowing the use of unstructured meshes that can accurately capture discontinuous material interfaces. This abstract describes our initial findings when using DG methods combined with Runge-Kutta time integration and adjoint-based optimization algorithms for full-waveform inversion. Our initial results suggest that DG methods allow great flexibility in matching the media characteristics (faults, ocean bottom and salt structures) while also providing higher fidelity representations in target regions. Time-domain inversion using discontinuous Galerkin on unstructured meshes and with local polynomial refinement is shown to better capture localized geological features and accurately capture discontinuous-material interfaces. These approaches provide the ability to surgically refine representations in order to improve predicted models for specific geological features. Our future work will entail automated extensions to directly incorporate local refinement and adaptive unstructured meshes within the inversion process.

  16. Inverse Functions and their Derivatives.

    ERIC Educational Resources Information Center

    Snapper, Ernst

    1990-01-01

    Presented is a method of interchanging the x-axis and y-axis for viewing the graph of the inverse function. Discussed are the inverse function and the usual proofs that are used for the function. (KR)

  17. Intersections, ideals, and inversion

    SciTech Connect

    Vasco, D.W.

    1998-10-01

    Techniques from computational algebra provide a framework for treating large classes of inverse problems. In particular, the discretization of many types of integral equations and of partial differential equations with undetermined coefficients lead to systems of polynomial equations. The structure of the solution set of such equations may be examined using algebraic techniques.. For example, the existence and dimensionality of the solution set may be determined. Furthermore, it is possible to bound the total number of solutions. The approach is illustrated by a numerical application to the inverse problem associated with the Helmholtz equation. The algebraic methods are used in the inversion of a set of transverse electric (TE) mode magnetotelluric data from Antarctica. The existence of solutions is demonstrated and the number of solutions is found to be finite, bounded from above at 50. The best fitting structure is dominantly onedimensional with a low crustal resistivity of about 2 ohm-m. Such a low value is compatible with studies suggesting lower surface wave velocities than found in typical stable cratons.

  18. Towards adaptive IMRT sequencing for the MR-linac.

    PubMed

    Kontaxis, C; Bol, G H; Lagendijk, J J W; Raaymakers, B W

    2015-03-21

    The MRI linear accelerator (MR-linac) that is currently being installed in the University Medical Center Utrecht (Utrecht, The Netherlands), will be able to track the patient's target(s) and Organ(s) At Risk during radiation delivery. In this paper, we present a treatment planning system for intensity-modulated radiotherapy (IMRT). It is capable of Adaptive Radiotherapy and consists of a GPU Monte Carlo dose engine, an inverse dose optimization algorithm and a novel adaptive sequencing algorithm. The system is able to compensate for patient anatomy changes and enables radiation delivery immediately from the first calculated segment. IMRT plans meeting all clinical constraints were generated for two breast cases, one spinal bone metastasis case, two prostate cases with integrated boost regions and one head and neck case. These plans were generated by the segment weighted version of our algorithm, in a 0 T environment in order to test the feasibility of the new sequencing strategy in current clinical conditions, yielding very small differences between the fluence and sequenced distributions. All plans went through stringent experimental quality assurance on Delta4 and passed all clinical tests currently performed in our institute. A new inter-fraction adaptation scheme built on top of this algorithm is also proposed that enables convergence to the ideal dose distribution without the need of a final segment weight optimization. The first results of this method confirm that convergence is achieved within the first fractions of the treatment. These features combined will lead to a fully adaptive intra-fraction planning system able to take into account patient anatomy updates during treatment. PMID:25749856

  19. Towards adaptive IMRT sequencing for the MR-linac

    NASA Astrophysics Data System (ADS)

    Kontaxis, C.; Bol, G. H.; Lagendijk, J. J. W.; Raaymakers, B. W.

    2015-03-01

    The MRI linear accelerator (MR-linac) that is currently being installed in the University Medical Center Utrecht (Utrecht, The Netherlands), will be able to track the patient’s target(s) and Organ(s) At Risk during radiation delivery. In this paper, we present a treatment planning system for intensity-modulated radiotherapy (IMRT). It is capable of Adaptive Radiotherapy and consists of a GPU Monte Carlo dose engine, an inverse dose optimization algorithm and a novel adaptive sequencing algorithm. The system is able to compensate for patient anatomy changes and enables radiation delivery immediately from the first calculated segment. IMRT plans meeting all clinical constraints were generated for two breast cases, one spinal bone metastasis case, two prostate cases with integrated boost regions and one head and neck case. These plans were generated by the segment weighted version of our algorithm, in a 0 T environment in order to test the feasibility of the new sequencing strategy in current clinical conditions, yielding very small differences between the fluence and sequenced distributions. All plans went through stringent experimental quality assurance on Delta4 and passed all clinical tests currently performed in our institute. A new inter-fraction adaptation scheme built on top of this algorithm is also proposed that enables convergence to the ideal dose distribution without the need of a final segment weight optimization. The first results of this method confirm that convergence is achieved within the first fractions of the treatment. These features combined will lead to a fully adaptive intra-fraction planning system able to take into account patient anatomy updates during treatment.

  20. Preview-Based Stable-Inversion for Output Tracking

    NASA Technical Reports Server (NTRS)

    Zou, Qing-Ze; Devasia, Santosh

    1999-01-01

    Stable Inversion techniques can be used to achieve high-accuracy output tracking. However, for nonminimum phase systems, the inverse is non-causal - hence the inverse has to be pre-computed using a pre-specified desired-output trajectory. This requirement for pre-specification of the desired output restricts the use of inversion-based approaches to trajectory planning problems (for nonminimum phase systems). In the present article, it is shown that preview information of the desired output can be used to achieve online inversion-based output tracking of linear systems. The amount of preview-time needed is quantified in terms of the tracking error and the internal dynamics of the system (zeros of the system). The methodology is applied to the online output tracking of a flexible structure and experimental results are presented.

  1. Darwin's “strange inversion of reasoning”

    PubMed Central

    Dennett, Daniel

    2009-01-01

    Darwin's theory of evolution by natural selection unifies the world of physics with the world of meaning and purpose by proposing a deeply counterintuitive “inversion of reasoning” (according to a 19th century critic): “to make a perfect and beautiful machine, it is not requisite to know how to make it” [MacKenzie RB (1868) (Nisbet & Co., London)]. Turing proposed a similar inversion: to be a perfect and beautiful computing machine, it is not requisite to know what arithmetic is. Together, these ideas help to explain how we human intelligences came to be able to discern the reasons for all of the adaptations of life, including our own. PMID:19528651

  2. Climate change adaptation planning for the Skeena region of British Columbia, Canada: A combined biophysical modelling, social science, and community engagement approach

    NASA Astrophysics Data System (ADS)

    Melton, J. R.; Kaplan, J. O.; Matthews, R.; Sydneysmith, R.; Tesluk, J.; Piggot, G.; Robinson, D. C.; Brinkman, D.; Marmorek, D.; Cohen, S.; McPherson, K.

    2011-12-01

    The Skeena region of British Columbia, Canada is among the world's most important commercial forest production areas, a key transportation corridor, and provides critical habitat for salmon and other wildlife. Climate change compounds threats to the region from other local environmental and social challenges. To aid local communities in adaptive planning for future climate change impacts, our project combined biophysical modelling, social science, and community engagement in a participatory approach to build regional capacity to prepare and respond to climate change. The sociological aspect of our study interviewed local leaders and resource managers (both First Nations and settlers groups in three communities) to examine how perceptions of environmental and socioeconomic issues have changed in the recent past, and the values placed on diverse natural resources at the present. The three communities differed in their perception of the relative value and condition of community resources, such as small business, natural resource trade, education and local government. However, all three communities regarded salmon as their most important and threatened resource. The most important future drivers of change in the study region were perceived to be: "aboriginal rights, title and treaty settlements", "availability of natural resources", "natural resource policies", and the "global economy". Climate change, as a potential driver of change in the region, was perceived as less important than other socio-economic factors; even though climate records for the region already demonstrate warmer winters, decreased snowfall, and decreased spring precipitation over the last half century. The natural science component of our project applies a regional-scale dynamic vegetation model (LPJ-GUESS) to simulate the potential future of forest ecosystems, with a focus on how climate change and management strategy interact to influence forest productivity, disturbance frequency, species

  3. Mission planning for autonomous systems

    NASA Technical Reports Server (NTRS)

    Pearson, G.

    1987-01-01

    Planning is a necessary task for intelligent, adaptive systems operating independently of human controllers. A mission planning system that performs task planning by decomposing a high-level mission objective into subtasks and synthesizing a plan for those tasks at varying levels of abstraction is discussed. Researchers use a blackboard architecture to partition the search space and direct the focus of attention of the planner. Using advanced planning techniques, they can control plan synthesis for the complex planning tasks involved in mission planning.

  4. Final Technical Report for "Applied Mathematics Research: Simulation Based Optimization and Application to Electromagnetic Inverse Problems"

    SciTech Connect

    Haber, Eldad

    2014-03-17

    The focus of research was: Developing adaptive mesh for the solution of Maxwell's equations; Developing a parallel framework for time dependent inverse Maxwell's equations; Developing multilevel methods for optimization problems with inequal- ity constraints; A new inversion code for inverse Maxwell's equations in the 0th frequency (DC resistivity); A new inversion code for inverse Maxwell's equations in low frequency regime. Although the research concentrated on electromagnetic forward and in- verse problems the results of the research was applied to the problem of image registration.

  5. Improvements of Travel-time Tomography Models from Joint Inversion of Multi-channel and Wide-angle Seismic Data

    NASA Astrophysics Data System (ADS)

    Begović, Slaven; Ranero, César; Sallarès, Valentí; Meléndez, Adrià; Grevemeyer, Ingo

    2016-04-01

    Commonly multichannel seismic reflection (MCS) and wide-angle seismic (WAS) data are modeled and interpreted with different approaches. Conventional travel-time tomography models using solely WAS data lack the resolution to define the model properties and, particularly, the geometry of geologic boundaries (reflectors) with the required accuracy, specially in the shallow complex upper geological layers. We plan to mitigate this issue by combining these two different data sets, specifically taking advantage of the high redundancy of multichannel seismic (MCS) data, integrated with wide-angle seismic (WAS) data into a common inversion scheme to obtain higher-resolution velocity models (Vp), decrease Vp uncertainty and improve the geometry of reflectors. To do so, we have adapted the tomo2d and tomo3d joint refraction and reflection travel time tomography codes (Korenaga et al, 2000; Meléndez et al, 2015) to deal with streamer data and MCS acquisition geometries. The scheme results in a joint travel-time tomographic inversion based on integrated travel-time information from refracted and reflected phases from WAS data and reflected identified in the MCS common depth point (CDP) or shot gathers. To illustrate the advantages of a common inversion approach we have compared the modeling results for synthetic data sets using two different travel-time inversion strategies: We have produced seismic velocity models and reflector geometries following typical refraction and reflection travel-time tomographic strategy modeling just WAS data with a typical acquisition geometry (one OBS each 10 km). Second, we performed joint inversion of two types of seismic data sets, integrating two coincident data sets consisting of MCS data collected with a 8 km-long streamer and the WAS data into a common inversion scheme. Our synthetic results of the joint inversion indicate a 5-10 times smaller ray travel-time misfit in the deeper parts of the model, compared to models obtained using just

  6. Adaptive techniques in electrical impedance tomography reconstruction.

    PubMed

    Li, Taoran; Isaacson, David; Newell, Jonathan C; Saulnier, Gary J

    2014-06-01

    We present an adaptive algorithm for solving the inverse problem in electrical impedance tomography. To strike a balance between the accuracy of the reconstructed images and the computational efficiency of the forward and inverse solvers, we propose to combine an adaptive mesh refinement technique with the adaptive Kaczmarz method. The iterative algorithm adaptively generates the optimal current patterns and a locally-refined mesh given the conductivity estimate and solves for the unknown conductivity distribution with the block Kaczmarz update step. Simulation and experimental results with numerical analysis demonstrate the accuracy and the efficiency of the proposed algorithm.

  7. Addressing Climate Change Adaptation in Regional Transportation Plans in California: A Guide and Online Visualization Tool for Planners to Incorporate Risks of Climate Change Impacts in Policy and Decision-Making

    NASA Astrophysics Data System (ADS)

    Tao, W.; Tucker, K.; DeFlorio, J.

    2012-12-01

    for the strategy framework. The strategy framework for MPOs and RTPAs is used to: 1) Assess the relative risks to their transportation system infrastructure and services of different climate stressors (sea level rise, temperature changes, snow melt, precipita¬tion changes, flooding, extreme weather events); 2) Conduct an asset inventory and vulnerability assessment of existing infrastructure; 3) Prioritize segments and facilities for adaptation action; 4) Identify appropriate and cost-effective adaptation strategies; and 5) Incorporate climate impact considerations into future long-range transportation planning and investment decisions. This framework complements the broader planning and investment processes that MPOs and RTPAs already manage. It recognizes the varying capacities and resources among MPOs and RTPAs and provide methods that can be used by organizations seeking to conduct in-depth analysis or a more sketch-level assessment.

  8. Advanced Adaptive Optics Technology Development

    SciTech Connect

    Olivier, S

    2001-09-18

    The NSF Center for Adaptive Optics (CfAO) is supporting research on advanced adaptive optics technologies. CfAO research activities include development and characterization of micro-electro-mechanical systems (MEMS) deformable mirror (DM) technology, as well as development and characterization of high-resolution adaptive optics systems using liquid crystal (LC) spatial light modulator (SLM) technology. This paper presents an overview of the CfAO advanced adaptive optics technology development activities including current status and future plans.

  9. Joint Applications Pilot of the National Climate Predictions and Projections Platform and the North Central Climate Science Center: Delivering climate projections on regional scales to support adaptation planning

    NASA Astrophysics Data System (ADS)

    Ray, A. J.; Ojima, D. S.; Morisette, J. T.

    2012-12-01

    The DOI North Central Climate Science Center (NC CSC) and the NOAA/NCAR National Climate Predictions and Projections (NCPP) Platform and have initiated a joint pilot study to collaboratively explore the "best available climate information" to support key land management questions and how to provide this information. NCPP's mission is to support state of the art approaches to develop and deliver comprehensive regional climate information and facilitate its use in decision making and adaptation planning. This presentation will describe the evolving joint pilot as a tangible, real-world demonstration of linkages between climate science, ecosystem science and resource management. Our joint pilot is developing a deliberate, ongoing interaction to prototype how NCPP will work with CSCs to develop and deliver needed climate information products, including translational information to support climate data understanding and use. This pilot also will build capacity in the North Central CSC by working with NCPP to use climate information used as input to ecological modeling. We will discuss lessons to date on developing and delivering needed climate information products based on this strategic partnership. Four projects have been funded to collaborate to incorporate climate information as part of an ecological modeling project, which in turn will address key DOI stakeholder priorities in the region: Riparian Corridors: Projecting climate change effects on cottonwood and willow seed dispersal phenology, flood timing, and seedling recruitment in western riparian forests. Sage Grouse & Habitats: Integrating climate and biological data into land management decision models to assess species and habitat vulnerability Grasslands & Forests: Projecting future effects of land management, natural disturbance, and CO2 on woody encroachment in the Northern Great Plains The value of climate information: Supporting management decisions in the Plains and Prairie Potholes LCC. NCCSC's role in

  10. Adaptive nonlinear flight control

    NASA Astrophysics Data System (ADS)

    Rysdyk, Rolf Theoduor

    1998-08-01

    Research under supervision of Dr. Calise and Dr. Prasad at the Georgia Institute of Technology, School of Aerospace Engineering. has demonstrated the applicability of an adaptive controller architecture. The architecture successfully combines model inversion control with adaptive neural network (NN) compensation to cancel the inversion error. The tiltrotor aircraft provides a specifically interesting control design challenge. The tiltrotor aircraft is capable of converting from stable responsive fixed wing flight to unstable sluggish hover in helicopter configuration. It is desirable to provide the pilot with consistency in handling qualities through a conversion from fixed wing flight to hover. The linear model inversion architecture was adapted by providing frequency separation in the command filter and the error-dynamics, while not exiting the actuator modes. This design of the architecture provides for a model following setup with guaranteed performance. This in turn allowed for convenient implementation of guaranteed handling qualities. A rigorous proof of boundedness is presented making use of compact sets and the LaSalle-Yoshizawa theorem. The analysis allows for the addition of the e-modification which guarantees boundedness of the NN weights in the absence of persistent excitation. The controller is demonstrated on the Generic Tiltrotor Simulator of Bell-Textron and NASA Ames R.C. The model inversion implementation is robustified with respect to unmodeled input dynamics, by adding dynamic nonlinear damping. A proof of boundedness of signals in the system is included. The effectiveness of the robustification is also demonstrated on the XV-15 tiltrotor. The SHL Perceptron NN provides a more powerful application, based on the universal approximation property of this type of NN. The SHL NN based architecture is also robustified with the dynamic nonlinear damping. A proof of boundedness extends the SHL NN augmentation with robustness to unmodeled actuator

  11. Chromosome inversion polymorphisms influence morphological traits in Trimerotropis pallidipennis (Orthoptera).

    PubMed

    Colombo, P C

    2002-04-01

    Trimerotropis pallidipennis is a New World grasshopper whose South-American populations are polymorphic for six pericentric inversions. Previous work has demonstrated that the frequences of these inversions correlate with climatic variables, and hence a possible adaptive pattern was put forward. In the present work we analysed a sample of a natural population of T pallidipennis to ascertain whether the chromosomal inversions have effects on exophenotypes. Two hundred and sixty-eight males coming from a natural population at Uspallata, Mendoza Province, Argentina were analysed, and it was observed that most inversions had significant effects on phenotypes. Furthermore, some body size-related characteristics (such as tegmina length) were correlated with the number of inversions. Individuals from populations at higher altitude or latitude (i.e., at lower minimum temperatures), along with higher frequencies of standard sequences, were significantly smaller, and this coherence between interpopulational with intrapopulational results may indicate that the diminished body size of the standard sequence-carrying individuals may be caused by an effect of the inversions, or genes within the inversions, on body size. We finally put forward the hypothesis that reduced body size in a context of reduced minimum temperature may be a response to shortened development season, and so smaller individuals may be advantageous.

  12. Stress inversion assumptions review

    NASA Astrophysics Data System (ADS)

    Lejri, Mostfa; Maerten, Frantz; Maerten, Laurent; Joonnenkindt, Jean Pierre; Soliva, Roger

    2014-05-01

    Wallace (1951) and Bott (1959) were the first to introduce the idea that the slip on each fault surface has the same direction and sense as the maximum shear stress resolved on that surface. This hypothesis are based on the assumptions that (i) faults are planar, (ii) blocks are rigid, (iii) neither stress perturbations nor block rotations along fault surfaces occur and (iv), the applied stress state is uniform. However, this simplified hypothesis is questionable since complex fault geometries, heterogeneous fault slip directions, evidences of stress perturbations in microstructures and block rotations along fault surfaces were reported in the literature. Earlier numerical geomechanical models confirmed that the striation lines (slip vectors) are not necessarily parallel to the maximum shear stress vector but is consistent with local stress perturbations. This leads us to ask as to what extent the Wallace and Bott simplifications are reliable as a basis hypothesis for stress inversion. In this presentation, a geomechanical multi-parametric study using 3D boundary element method (BEM), covering (i) fault geometries such as intersected faults or corrugated fault surfaces, (ii) the full range of Andersonian state of stress, (iii) fault friction, (iv) half space effect and (v), rock properties, is performed in order to understand the effect of each parameter on the angular misfit between geomechanical slip vectors and the resolved shear stresses. It is shown that significant angular misfits can be found under specific configurations and therefore we conclude that stress inversions based on the Wallace-Bott hypothesis might sometime give results that should be interpreted with care. Major observations are that (i) applying optimum tectonic stress conditions on complex fault geometries can increase the angular misfit, (ii) elastic material properties, combined to half-space effect, can enhance this effect, and (iii) an increase of the sliding friction leads to a

  13. Inverse magnetorheological fluids.

    PubMed

    Rodríguez-Arco, L; López-López, M T; Zubarev, A Y; Gdula, K; Durán, J D G

    2014-09-01

    We report a new kind of field-responsive fluid consisting of suspensions of diamagnetic (DM) and ferromagnetic (FM) microparticles in ferrofluids. We designate them as inverse magnetorheological (IMR) fluids for analogy with inverse ferrofluids (IFFs). Observations on the particle self-assembly in IMR fluids upon magnetic field application showed that DM and FM microparticles were assembled into alternating chains oriented along the field direction. We explain such assembly on the basis of the dipolar interaction energy between particles. We also present results on the rheological properties of IMR fluids and, for comparison, those of IFFs and bidispersed magnetorheological (MR) fluids. Interestingly, we found that upon magnetic field application, the rheological properties of IMR fluids were enhanced with respect to bidispersed MR fluids with the same FM particle concentration, by an amount greater than the sum of the isolated contribution of DM particles. Furthermore, the field-induced yield stress was moderately increased when up to 30% of the total FM particle content was replaced with DM particles. Beyond this point, the dependence of the yield stress on the DM content was non-monotonic, as expected for FM concentrations decreasing to zero. We explain these synergistic results by two separate phenomena: the formation of exclusion areas for FM particles due to the perturbation of the magnetic field by DM particles and the dipole-dipole interaction between DM and FM particles, which enhances the field-induced structures. Based on the second phenomenon, we present a theoretical model for the yield stress that semi-quantitatively predicts the experimental results. PMID:25022363

  14. Wavelet Sparse Approximate Inverse Preconditioners

    NASA Technical Reports Server (NTRS)

    Chan, Tony F.; Tang, W.-P.; Wan, W. L.

    1996-01-01

    There is an increasing interest in using sparse approximate inverses as preconditioners for Krylov subspace iterative methods. Recent studies of Grote and Huckle and Chow and Saad also show that sparse approximate inverse preconditioner can be effective for a variety of matrices, e.g. Harwell-Boeing collections. Nonetheless a drawback is that it requires rapid decay of the inverse entries so that sparse approximate inverse is possible. However, for the class of matrices that, come from elliptic PDE problems, this assumption may not necessarily hold. Our main idea is to look for a basis, other than the standard one, such that a sparse representation of the inverse is feasible. A crucial observation is that the kind of matrices we are interested in typically have a piecewise smooth inverse. We exploit this fact, by applying wavelet techniques to construct a better sparse approximate inverse in the wavelet basis. We shall justify theoretically and numerically that our approach is effective for matrices with smooth inverse. We emphasize that in this paper we have only presented the idea of wavelet approximate inverses and demonstrated its potential but have not yet developed a highly refined and efficient algorithm.

  15. Inverse problem for Bremsstrahlung radiation

    SciTech Connect

    Voss, K.E.; Fisch, N.J.

    1991-10-01

    For certain predominantly one-dimensional distribution functions, an analytic inversion has been found which yields the velocity distribution of superthermal electrons given their Bremsstrahlung radiation. 5 refs.

  16. Selection on Inversion Breakpoints Favors Proximity to Pairing Sensitive Sites in Drosophila melanogaster.

    PubMed

    Corbett-Detig, Russell B

    2016-09-01

    Chromosomal inversions are widespread among taxa, and have been implicated in a number of biological processes including adaptation, sex chromosome evolution, and segregation distortion. Consistent with selection favoring linkage between loci, it is well established that length is a selected trait of inversions. However, the factors that affect the distribution of inversion breakpoints remain poorly understood. "Sensitive sites" have been mapped on all euchromatic chromosome arms in Drosophila melanogaster, and may be a source of natural selection on inversion breakpoint positions. Briefly, sensitive sites are genomic regions wherein proximal structural rearrangements result in large reductions in local recombination rates in heterozygotes. Here, I show that breakpoints of common inversions are significantly more likely to lie within a cytological band containing a sensitive site than are breakpoints of rare inversions. Furthermore, common inversions for which neither breakpoint intersects a sensitive site are significantly longer than rare inversions, but common inversions whose breakpoints intersect a sensitive site show no evidence for increased length. I interpret these results to mean that selection favors inversions whose breakpoints disrupt synteny near to sensitive sites, possibly because these inversions suppress recombination in large genomic regions. To my knowledge this is the first evidence consistent with positive selection acting on inversion breakpoint positions. PMID:27343234

  17. Adapted Intervention Mapping: A Strategic Planning Process for Increasing Physical Activity and Healthy Eating Opportunities in Schools via Environment and Policy Change

    ERIC Educational Resources Information Center

    Belansky, Elaine S.; Cutforth, Nick; Chavez, Robert; Crane, Lori A.; Waters, Emily; Marshall, Julie A.

    2013-01-01

    Background: School environment and policy changes have increased healthy eating and physical activity; however, there has been modest success in translating research ?ndings to practice. The School Environment Project tested whether an adapted version of Intervention Mapping (AIM) resulted in school change. Methods: Using a pair randomized design,…

  18. Adapting the Primary-School Curriculum for Multigrade Classes in Developing Countries: A Five-Step Plan and an Agenda for Change

    ERIC Educational Resources Information Center

    Pridmore, Pat

    2007-01-01

    This paper draws on the findings from an international programme of research that has demonstrated the need for teachers in many developing countries to be given more support in adapting monograded curricula to the needs of their multigrade classes. It describes four empirical models of multigrade practice and examines the models of curriculum…

  19. Experience Gained during the Adaptation of Classical ChE Subjects to the Bologna Plan in Europe: The Case of Chemical Reactors

    ERIC Educational Resources Information Center

    Ponsa, Sergio; Sanchez, Antoni

    2011-01-01

    At present, due to the overall adaptation to the European Higher Education Area (EHEA), a new concept regarding the teaching methodology was thought to be essential for engineering subjects. In this paper we describe our experience teaching the altered content of the courses on two classical subjects; Chemical Reactors (Chemical Engineering) and…

  20. Modular theory of inverse systems

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The relationship between multivariable zeros and inverse systems was explored. A definition of zero module is given in such a way that it is basis independent. The existence of essential right and left inverses were established. The way in which the abstract zero module captured previous definitions of multivariable zeros is explained and examples are presented.

  1. Inversion exercises inspired by mechanics

    NASA Astrophysics Data System (ADS)

    Groetsch, C. W.

    2016-02-01

    An elementary calculus transform, inspired by the centroid and gyration radius, is introduced as a prelude to the study of more advanced transforms. Analysis of the transform, including its inversion, makes use of several key concepts from basic calculus and exercises in the application and inversion of the transform provide practice in the use of technology in calculus.

  2. Estimating patient specific uncertainty parameters for adaptive treatment re-planning in proton therapy using in vivo range measurements and Bayesian inference: application to setup and stopping power errors.

    PubMed

    Labarbe, Rudi; Janssens, Guillaume; Sterpin, Edmond

    2016-09-01

    In proton therapy, quantification of the proton range uncertainty is important to achieve dose distribution compliance. The promising accuracy of prompt gamma imaging (PGI) suggests the development of a mathematical framework using the range measurements to convert population based estimates of uncertainties into patient specific estimates with the purpose of plan adaptation. We present here such framework using Bayesian inference. The sources of uncertainty were modeled by three parameters: setup bias m, random setup precision r and water equivalent path length bias u. The evolution of the expectation values E(m), E(r) and E(u) during the treatment was simulated. The expectation values converged towards the true simulation parameters after 5 and 10 fractions, for E(m) and E(u), respectively. E(r) settle on a constant value slightly lower than the true value after 10 fractions. In conclusion, the simulation showed that there is enough information in the frequency distribution of the range errors measured by PGI to estimate the expectation values and the confidence interval of the model parameters by Bayesian inference. The updated model parameters were used to compute patient specific lateral and local distal margins for adaptive re-planning. PMID:27494118

  3. Estimating patient specific uncertainty parameters for adaptive treatment re-planning in proton therapy using in vivo range measurements and Bayesian inference: application to setup and stopping power errors

    NASA Astrophysics Data System (ADS)

    Labarbe, Rudi; Janssens, Guillaume; Sterpin, Edmond

    2016-09-01

    In proton therapy, quantification of the proton range uncertainty is important to achieve dose distribution compliance. The promising accuracy of prompt gamma imaging (PGI) suggests the development of a mathematical framework using the range measurements to convert population based estimates of uncertainties into patient specific estimates with the purpose of plan adaptation. We present here such framework using Bayesian inference. The sources of uncertainty were modeled by three parameters: setup bias m, random setup precision r and water equivalent path length bias u. The evolution of the expectation values E(m), E(r) and E(u) during the treatment was simulated. The expectation values converged towards the true simulation parameters after 5 and 10 fractions, for E(m) and E(u), respectively. E(r) settle on a constant value slightly lower than the true value after 10 fractions. In conclusion, the simulation showed that there is enough information in the frequency distribution of the range errors measured by PGI to estimate the expectation values and the confidence interval of the model parameters by Bayesian inference. The updated model parameters were used to compute patient specific lateral and local distal margins for adaptive re-planning.

  4. Inverse Problems of Thermoelectricity

    NASA Astrophysics Data System (ADS)

    Anatychuk, L. I.; Luste, O. J.; Kuz, R. V.; Strutinsky, M. N.

    2011-05-01

    Classical thermoelectricity is based on the use of the Seebeck and Thomson effects that occur in the near-contact areas between n- and p-type materials. A conceptually different approach to thermoelectric power converter design that is based on the law of thermoelectric induction of currents is also known. The efficiency of this approach has already been demonstrated by its first applications. More than 10 basically new types of thermoelements were discovered with properties that cannot be achieved by thermocouple power converters. Therefore, further development of this concept is of practical interest. This paper provides a classification and theory for solving the inverse problems of thermoelectricity that form the basis for devising new thermoelement types. Computer methods for their solution for anisotropic and inhomogeneous media are elaborated. Regularities related to thermoelectric current excitation in anisotropic and inhomogeneous media are established. The possibility of obtaining eddy currents of a particular configuration through control of the temperature field and material parameters for the creation of new thermo- element types is demonstrated for three-dimensional (3D) models of anisotropic and inhomogeneous media.

  5. Inverse problem in hydrogeology

    NASA Astrophysics Data System (ADS)

    Carrera, Jesús; Alcolea, Andrés; Medina, Agustín; Hidalgo, Juan; Slooten, Luit J.

    2005-03-01

    The state of the groundwater inverse problem is synthesized. Emphasis is placed on aquifer characterization, where modelers have to deal with conceptual model uncertainty (notably spatial and temporal variability), scale dependence, many types of unknown parameters (transmissivity, recharge, boundary conditions, etc.), nonlinearity, and often low sensitivity of state variables (typically heads and concentrations) to aquifer properties. Because of these difficulties, calibration cannot be separated from the modeling process, as it is sometimes done in other fields. Instead, it should be viewed as one step in the process of understanding aquifer behavior. In fact, it is shown that actual parameter estimation methods do not differ from each other in the essence, though they may differ in the computational details. It is argued that there is ample room for improvement in groundwater inversion: development of user-friendly codes, accommodation of variability through geostatistics, incorporation of geological information and different types of data (temperature, occurrence and concentration of isotopes, age, etc.), proper accounting of uncertainty, etc. Despite this, even with existing codes, automatic calibration facilitates enormously the task of modeling. Therefore, it is contended that its use should become standard practice. L'état du problème inverse des eaux souterraines est synthétisé. L'accent est placé sur la caractérisation de l'aquifère, où les modélisateurs doivent jouer avec l'incertitude des modèles conceptuels (notamment la variabilité spatiale et temporelle), les facteurs d'échelle, plusieurs inconnues sur différents paramètres (transmissivité, recharge, conditions aux limites, etc.), la non linéarité, et souvent la sensibilité de plusieurs variables d'état (charges hydrauliques, concentrations) des propriétés de l'aquifère. A cause de ces difficultés, le calibrage ne peut êtreséparé du processus de modélisation, comme c'est le

  6. Polarization of inverse plasmon scattering

    NASA Technical Reports Server (NTRS)

    Windsor, R. A.; Kellogg, P. J.

    1974-01-01

    The scattering of electrostatic plasma waves by a flux of ultrarelativistic electrons passing through a plasma gives rise to a radiation spectrum which is similar to a synchrotron radiation spectrum. This mechanism, first considered by Gailitis and Tsytovich, is analagous to inverse Compton scattering, and we have named it inverse plasmon scattering. For a power-law electron flux, both inverse plasmon scattering and synchrotron radiation have the same spectral index. In an attempt to distinguish between these mechanisms, we have calculated the polarization level expected from inverse plasmon scattering. The polarization level found is similar to that obtained from a synchrotron radiation source. This means that the radiation produced by two mechanisms, synchrotron radiation and inverse plasmon scattering, is indistinguishable; and this attempt to differentiate between them by polarization effects has been unsuccessful.

  7. A randomised trial of adaptive pacing therapy, cognitive behaviour therapy, graded exercise, and specialist medical care for chronic fatigue syndrome (PACE): statistical analysis plan

    PubMed Central

    2013-01-01

    Background The publication of protocols by medical journals is increasingly becoming an accepted means for promoting good quality research and maximising transparency. Recently, Finfer and Bellomo have suggested the publication of statistical analysis plans (SAPs).The aim of this paper is to make public and to report in detail the planned analyses that were approved by the Trial Steering Committee in May 2010 for the principal papers of the PACE (Pacing, graded Activity, and Cognitive behaviour therapy: a randomised Evaluation) trial, a treatment trial for chronic fatigue syndrome. It illustrates planned analyses of a complex intervention trial that allows for the impact of clustering by care providers, where multiple care-providers are present for each patient in some but not all arms of the trial. Results The trial design, objectives and data collection are reported. Considerations relating to blinding, samples, adherence to the protocol, stratification, centre and other clustering effects, missing data, multiplicity and compliance are described. Descriptive, interim and final analyses of the primary and secondary outcomes are then outlined. Conclusions This SAP maximises transparency, providing a record of all planned analyses, and it may be a resource for those who are developing SAPs, acting as an illustrative example for teaching and methodological research. It is not the sum of the statistical analysis sections of the principal papers, being completed well before individual papers were drafted. Trial registration ISRCTN54285094 assigned 22 May 2003; First participant was randomised on 18 March 2005. PMID:24225069

  8. Performance-optimized clinical IMRT planning on modern CPUs

    NASA Astrophysics Data System (ADS)

    Ziegenhein, Peter; Kamerling, Cornelis Ph; Bangert, Mark; Kunkel, Julian; Oelfke, Uwe

    2013-06-01

    Intensity modulated treatment plan optimization is a computationally expensive task. The feasibility of advanced applications in intensity modulated radiation therapy as every day treatment planning, frequent re-planning for adaptive radiation therapy and large-scale planning research severely depends on the runtime of the plan optimization implementation. Modern computational systems are built as parallel architectures to yield high performance. The use of GPUs, as one class of parallel systems, has become very popular in the field of medical physics. In contrast we utilize the multi-core central processing unit (CPU), which is the heart of every modern computer and does not have to be purchased additionally. In this work we present an ultra-fast, high precision implementation of the inverse plan optimization problem using a quasi-Newton method on pre-calculated dose influence data sets. We redefined the classical optimization algorithm to achieve a minimal runtime and high scalability on CPUs. Using the proposed methods in this work, a total plan optimization process can be carried out in only a few seconds on a low-cost CPU-based desktop computer at clinical resolution and quality. We have shown that our implementation uses the CPU hardware resources efficiently with runtimes comparable to GPU implementations, at lower costs.

  9. Scaling Climate Change Adaptation in the Northern Great Plains through Regional Climate Summaries and Local Qualitative-quantitative Scenario Planning Workshops

    NASA Astrophysics Data System (ADS)

    Ray, A. J.

    2015-12-01

    This presentation will describe a project to between ecologists and climate scientists to inform National Park Service managers who are developing scenario planning for their parks and surrounding areas; this effort is advancing scenario methodologies and improving delivery mechanisms and applications to decision-making for National Parks. Climate change is expressed in both regional climatic shifts (e.g., temperature and precipitation changes) and local resource impacts. Resource management in a changing climate is challenging because future climate change and resource responses cannot be precisely predicted. Scenario planning is a tool to assess the range of plausible future conditions. However, selecting, acquiring, synthesizing, and scaling climate information for scenario planning requires significant time and skills. This project, which was recently selected for funding by the NC CSC, has three goals: 1) synthesize climate data into 3-5 distinctly different but plausible climate summaries for the northern Great Plains region; 2) craft summaries of these climate futures that are relevant to local land management units; and 3) apply these local summaries to further develop quantitative climate-resource-management scenarios through participatory workshops and simulation models. We will engage multiple stakeholders in two focal areas within the region: southwestern South Dakota in the vicinity of Badlands National Park, and central North Dakota in the vicinity of Knife River Indian Villages National Historic Site. This effort will increase climate change planning efficiency in the region; promote collaborations across jurisdictions; and develop a prototype for a novel, efficient, and replicable form of scenario planning that could serve additional management units.

  10. Stylolite stress inversion

    NASA Astrophysics Data System (ADS)

    Koehn, Daniel; Toussaint, Renaud; Ebner, Marcus; Gomez-Rivas, Enrique; Bons, Paul; Rood, Daisy

    2014-05-01

    Stylolites are localized dissolution seams that can be found in a variety of rocks, and can form due to sediment compaction or tectonic forces. Dissolution of the host-rock next to the stylolite is a function of the applied stress on the stylolite plane. Stylolite teeth indicate the direction of the main compressive stress. Recent advances have shown that the stylolite roughness also shows a stress scaling relation that can be used to calculate magnitudes of stress. Elastic and surface energies produce a different roughness, and the transition between the two is stress dependent and can be quantified. In order to measure the roughness a two or three-dimensional section of a stylolite plane is taken and transferred to a one-dimensional function. The cross-over in the roughness is then picked with the help of an FFT plot. Using this method the burial depth of sedimentary stylolites can be determined. Moreover, tectonic stylolites can be used to determine the full three-dimensional stress tensor if the paleodepth of the tectonic stylolite is known. Stylolites can also be used to find fault offsets and to understand when these faults were active and how the paleotopography looked like at the time the stylolites grew. However, uncertainties remain since Youngs Modulus, Poisson Ratio and surface energy may vary in rocks. In addition, the stylolites record only a snapshot in time, probably the moment when they closed and stopped dissolving. We show examples of the use of stress inversion for stylolite formation conditions in different tectonic settings, and discuss the potential of the method.

  11. Microwave inverse Cerenkov accelerator

    NASA Astrophysics Data System (ADS)

    Zhang, T. B.; Marshall, T. C.; LaPointe, M. A.; Hirshfield, J. L.

    1997-03-01

    A Microwave Inverse Cerenkov Accelerator (MICA) is currently under construction at the Yale Beam Physics Laboratory. The accelerating structure in MICA consists of an axisymmetric dielectrically lined waveguide. For the injection of 6 MeV microbunches from a 2.856 GHz RF gun, and subsequent acceleration by the TM01 fields, particle simulation studies predict that an acceleration gradient of 6.3 MV/m can be achieved with a traveling-wave power of 15 MW applied to the structure. Synchronous injection into a narrow phase window is shown to allow trapping of all injected particles. The RF fields of the accelerating structure are shown to provide radial focusing, so that longitudinal and transverse emittance growth during acceleration is small, and that no external magnetic fields are required for focusing. For 0.16 nC, 5 psec microbunches, the normalized emittance of the accelerated beam is predicted to be less than 5πmm-mrad. Experiments on sample alumina tubes have been conducted that verify the theoretical dispersion relation for the TM01 mode over a two-to-one range in frequency. No excitation of axisymmetric or non-axisymmetric competing waveguide modes was observed. High power tests showed that tangential electric fields at the inner surface of an uncoated sample of alumina pipe could be sustained up to at least 8.4 MV/m without breakdown. These considerations suggest that a MICA test accelerator can be built to examine these predictions using an available RF power source, 6 MeV RF gun and associated beam line.

  12. Temperature inversion in China seas

    NASA Astrophysics Data System (ADS)

    Hao, Jiajia; Chen, Yongli; Wang, Fan

    2010-12-01

    Temperature inversion was reported as a common phenomenon in the areas near the southeastern Chinese coast (region A), west and south of the Korean Peninsula (region B), and north and east of the Shandong Peninsula (region C) during October-May in the present study, based on hydrographic data archived from 1930 through 2001 (319,029 profiles). The inversion was found to be remarkable with obvious temporal and spatial variabilities in both magnitude and coverage, with higher probabilities in region A (up to about 60%) and region C (40%-50%) than in region B (15%-20%). The analysis shows that seasonal variation of the net air-sea heat flux is closely related to the occurrence time of the inversion in the three areas, while the Yangtze and Yellow river freshwater plumes in the surface layer and ocean origin saline water in the subsurface layer maintain stable stratification. It seems that the evaporation/excessive precipitation flux makes little contribution to maintaining the stable inversion. Advection of surface fresh water by the wind-driven coastal currents results in the expansion of inversion in regions A and C. The inversion lasts for the longest period in region A (October-May) sustained by the Taiwan Warm Current carrying the subsurface saline water, while evolution of the inversion in region B is mainly controlled by the Yellow Sea Warm Current.

  13. 11. Strategic planning.

    PubMed

    2014-05-01

    There are several types of planning processes and plans, including strategic, operational, tactical, and contingency. For this document, operational planning includes tactical planning. This chapter examines the strategic planning process and includes an introduction into disaster response plans. "A strategic plan is an outline of steps designed with the goals of the entire organisation as a whole in mind, rather than with the goals of specific divisions or departments". Strategic planning includes all measures taken to provide a broad picture of what must be achieved and in which order, including how to organise a system capable of achieving the overall goals. Strategic planning often is done pre-event, based on previous experience and expertise. The strategic planning for disasters converts needs into a strategic plan of action. Strategic plans detail the goals that must be achieved. The process of converting needs into plans has been deconstructed into its components and includes consideration of: (1) disaster response plans; (2) interventions underway or planned; (3) available resources; (4) current status vs. pre-event status; (5) history and experience of the planners; and (6) access to the affected population. These factors are tempered by the local: (a) geography; (b) climate; (c) culture; (d) safety; and (e) practicality. The planning process consumes resources (costs). All plans must be adapted to the actual conditions--things never happen exactly as planned.

  14. Givental Graphs and Inversion Symmetry

    NASA Astrophysics Data System (ADS)

    Dunin-Barkowski, Petr; Shadrin, Sergey; Spitz, Loek

    2013-05-01

    Inversion symmetry is a very non-trivial discrete symmetry of Frobenius manifolds. It was obtained by Dubrovin from one of the elementary Schlesinger transformations of a special ODE associated to a Frobenius manifold. In this paper, we review the Givental group action on Frobenius manifolds in terms of Feynman graphs and obtain an interpretation of the inversion symmetry in terms of the action of the Givental group. We also consider the implication of this interpretation of the inversion symmetry for the Schlesinger transformations and for the Hamiltonians of the associated principle hierarchy.

  15. Application of Adaptive Autopilot Designs for an Unmanned Aerial Vehicle

    NASA Technical Reports Server (NTRS)

    Shin, Yoonghyun; Calise, Anthony J.; Motter, Mark A.

    2005-01-01

    This paper summarizes the application of two adaptive approaches to autopilot design, and presents an evaluation and comparison of the two approaches in simulation for an unmanned aerial vehicle. One approach employs two-stage dynamic inversion and the other employs feedback dynamic inversions based on a command augmentation system. Both are augmented with neural network based adaptive elements. The approaches permit adaptation to both parametric uncertainty and unmodeled dynamics, and incorporate a method that permits adaptation during periods of control saturation. Simulation results for an FQM-117B radio controlled miniature aerial vehicle are presented to illustrate the performance of the neural network based adaptation.

  16. Uterine Inversion; A case report.

    PubMed

    Bouchikhi, C; Saadi, H; Fakhir, B; Chaara, H; Bouguern, H; Banani, A; Melhouf, Ma

    2008-01-01

    The puerperal uterine inversion is a rare and severe complication occurring in the third stage of labour. The mechanisms are not completely known. However, extrinsic factors such as oxytocic arrests after a prolonged labour, umbilical cord traction or abdominal expression are pointed. Other intrinsic factors such as primiparity, uterine hypotonia, various placental localizations, fundic myoma or short umbilical cord were also reported. The diagnosis of the uterine inversion is mainly supported by clinical symptoms. It is based on three elements: haemorrhage, shock and a strong pelvic pain. The immediate treatment of the uterine inversion is required. It is based on a medical reanimation associated with firstly a manual reduction then surgical treatment using various techniques. We report an observation of a 25 years old grand multiparous patient with a subacute uterine inversion after delivery at home. PMID:21516244

  17. Uterine Inversion; A case report

    PubMed Central

    Bouchikhi, C; Saadi, H; Fakhir, B; Chaara, H; Bouguern, H; Banani, A; Melhouf, MA

    2008-01-01

    The puerperal uterine inversion is a rare and severe complication occurring in the third stage of labour. The mechanisms are not completely known. However, extrinsic factors such as oxytocic arrests after a prolonged labour, umbilical cord traction or abdominal expression are pointed. Other intrinsic factors such as primiparity, uterine hypotonia, various placental localizations, fundic myoma or short umbilical cord were also reported. The diagnosis of the uterine inversion is mainly supported by clinical symptoms. It is based on three elements: haemorrhage, shock and a strong pelvic pain. The immediate treatment of the uterine inversion is required. It is based on a medical reanimation associated with firstly a manual reduction then surgical treatment using various techniques. We report an observation of a 25 years old grand multiparous patient with a subacute uterine inversion after delivery at home. PMID:21516244

  18. Testing earthquake source inversion methodologies

    USGS Publications Warehouse

    Page, M.; Mai, P.M.; Schorlemmer, D.

    2011-01-01

    Source Inversion Validation Workshop; Palm Springs, California, 11-12 September 2010; Nowadays earthquake source inversions are routinely performed after large earthquakes and represent a key connection between recorded seismic and geodetic data and the complex rupture process at depth. The resulting earthquake source models quantify the spatiotemporal evolution of ruptures. They are also used to provide a rapid assessment of the severity of an earthquake and to estimate losses. However, because of uncertainties in the data, assumed fault geometry and velocity structure, and chosen rupture parameterization, it is not clear which features of these source models are robust. Improved understanding of the uncertainty and reliability of earthquake source inversions will allow the scientific community to use the robust features of kinematic inversions to more thoroughly investigate the complexity of the rupture process and to better constrain other earthquakerelated computations, such as ground motion simulations and static stress change calculations.

  19. Donor states in inverse opals

    SciTech Connect

    Mahan, G. D.

    2014-09-21

    We calculate the binding energy of an electron bound to a donor in a semiconductor inverse opal. Inverse opals have two kinds of cavities, which we call octahedral and tetrahedral, according to their group symmetry. We put the donor in the center of each of these two cavities and obtain the binding energy. The binding energies become very large when the inverse opal is made from templates with small spheres. For spheres less than 50 nm in diameter, the donor binding can increase to several times its unconfined value. Then electrons become tightly bound to the donor and are unlikely to be thermally activated to the semiconductor conduction band. This conclusion suggests that inverse opals will be poor conductors.

  20. Temperature Inversions Have Cold Bottoms.

    ERIC Educational Resources Information Center

    Bohren, Craig F.; Brown, Gail M.

    1982-01-01

    Uses discussion and illustrations of several demonstrations on air temperature differences and atmospheric stability to explain the phenomena of temperature inversions. Relates this to the smog in Los Angeles and discusses the implications. (DC)

  1. Donor states in inverse opals

    NASA Astrophysics Data System (ADS)

    Mahan, G. D.

    2014-09-01

    We calculate the binding energy of an electron bound to a donor in a semiconductor inverse opal. Inverse opals have two kinds of cavities, which we call octahedral and tetrahedral, according to their group symmetry. We put the donor in the center of each of these two cavities and obtain the binding energy. The binding energies become very large when the inverse opal is made from templates with small spheres. For spheres less than 50 nm in diameter, the donor binding can increase to several times its unconfined value. Then electrons become tightly bound to the donor and are unlikely to be thermally activated to the semiconductor conduction band. This conclusion suggests that inverse opals will be poor conductors.

  2. Moebius inversion formula and inverting lattice sums

    NASA Astrophysics Data System (ADS)

    Millane, Rick P.

    2000-11-01

    The Mobius inversion formula is an interesting theorem from number theory that has application to a number inverse problems, particularly lattice problems. Specific inverse problems, however, often require related Mobius inversion formulae that can be derived from the fundamental formula. Derivation of such formulae is not easy for the non- specialist, however. Examples of the kinds of inversion formulae that can be derived and their application to inverse lattice problems are described.

  3. Adaptive Management

    EPA Science Inventory

    Adaptive management is an approach to natural resource management that emphasizes learning through management where knowledge is incomplete, and when, despite inherent uncertainty, managers and policymakers must act. Unlike a traditional trial and error approach, adaptive managem...

  4. Understanding Perceptions of Climate Change, Priorities, and Decision-Making among Municipalities in Lima, Peru to Better Inform Adaptation and Mitigation Planning.

    PubMed

    Siña, Mariella; Wood, Rachel C; Saldarriaga, Enrique; Lawler, Joshua; Zunt, Joseph; Garcia, Patricia; Cárcamo, César

    2016-01-01

    Climate change poses multiple risks to the population of Lima, the largest city and capital of Peru, located on the Pacific coast in a desert ecosystem. These risks include increased water scarcity, increased heat, and the introduction and emergence of vector-borne and other climate sensitive diseases. To respond to these threats, it is necessary for the government, at every level, to adopt more mitigation and adaptation strategies. Here, focus groups were conducted with representatives from five Lima municipalities to determine priorities, perception of climate change, and decision-making processes for implementing projects within each municipality. These factors can affect the ability and desire of a community to implement climate change adaptation and mitigation strategies. The results show that climate change and other environmental factors are of relatively low priority, whereas public safety and water and sanitation services are of highest concern. Perhaps most importantly, climate change is not well understood among the municipalities. Participants had trouble distinguishing climate change from other environmental issues and did not fully understand its causes and effects. Greater understanding of what climate change is and why it is important is necessary for it to become a priority for the municipalities. Different aspects of increased climate change awareness seem to be connected to having experienced extreme weather events, whether related or not to climate change, and to higher socioeconomic status. PMID:26808087

  5. Understanding Perceptions of Climate Change, Priorities, and Decision-Making among Municipalities in Lima, Peru to Better Inform Adaptation and Mitigation Planning

    PubMed Central

    Saldarriaga, Enrique; Lawler, Joshua; Zunt, Joseph; Garcia, Patricia; Cárcamo, César

    2016-01-01

    Climate change poses multiple risks to the population of Lima, the largest city and capital of Peru, located on the Pacific coast in a desert ecosystem. These risks include increased water scarcity, increased heat, and the introduction and emergence of vector-borne and other climate sensitive diseases. To respond to these threats, it is necessary for the government, at every level, to adopt more mitigation and adaptation strategies. Here, focus groups were conducted with representatives from five Lima municipalities to determine priorities, perception of climate change, and decision-making processes for implementing projects within each municipality. These factors can affect the ability and desire of a community to implement climate change adaptation and mitigation strategies. The results show that climate change and other environmental factors are of relatively low priority, whereas public safety and water and sanitation services are of highest concern. Perhaps most importantly, climate change is not well understood among the municipalities. Participants had trouble distinguishing climate change from other environmental issues and did not fully understand its causes and effects. Greater understanding of what climate change is and why it is important is necessary for it to become a priority for the municipalities. Different aspects of increased climate change awareness seem to be connected to having experienced extreme weather events, whether related or not to climate change, and to higher socioeconomic status. PMID:26808087

  6. Understanding Perceptions of Climate Change, Priorities, and Decision-Making among Municipalities in Lima, Peru to Better Inform Adaptation and Mitigation Planning.

    PubMed

    Siña, Mariella; Wood, Rachel C; Saldarriaga, Enrique; Lawler, Joshua; Zunt, Joseph; Garcia, Patricia; Cárcamo, César

    2016-01-01

    Climate change poses multiple risks to the population of Lima, the largest city and capital of Peru, located on the Pacific coast in a desert ecosystem. These risks include increased water scarcity, increased heat, and the introduction and emergence of vector-borne and other climate sensitive diseases. To respond to these threats, it is necessary for the government, at every level, to adopt more mitigation and adaptation strategies. Here, focus groups were conducted with representatives from five Lima municipalities to determine priorities, perception of climate change, and decision-making processes for implementing projects within each municipality. These factors can affect the ability and desire of a community to implement climate change adaptation and mitigation strategies. The results show that climate change and other environmental factors are of relatively low priority, whereas public safety and water and sanitation services are of highest concern. Perhaps most importantly, climate change is not well understood among the municipalities. Participants had trouble distinguishing climate change from other environmental issues and did not fully understand its causes and effects. Greater understanding of what climate change is and why it is important is necessary for it to become a priority for the municipalities. Different aspects of increased climate change awareness seem to be connected to having experienced extreme weather events, whether related or not to climate change, and to higher socioeconomic status.

  7. Path planning for robotic truss assembly

    NASA Technical Reports Server (NTRS)

    Sanderson, Arthur C.

    1993-01-01

    A new Potential Fields approach to the robotic path planning problem is proposed and implemented. Our approach, which is based on one originally proposed by Munger, computes an incremental joint vector based upon attraction to a goal and repulsion from obstacles. By repetitively adding and computing these 'steps', it is hoped (but not guaranteed) that the robot will reach its goal. An attractive force exerted by the goal is found by solving for the the minimum norm solution to the linear Jacobian equation. A repulsive force between obstacles and the robot's links is used to avoid collisions. Its magnitude is inversely proportional to the distance. Together, these forces make the goal the global minimum potential point, but local minima can stop the robot from ever reaching that point. Our approach improves on a basic, potential field paradigm developed by Munger by using an active, adaptive field - what we will call a 'flexible' potential field. Active fields are stronger when objects move towards one another and weaker when they move apart. An adaptive field's strength is individually tailored to be just strong enough to avoid any collision. In addition to the local planner, a global planning algorithm helps the planner to avoid local field minima by providing subgoals. These subgoals are based on the obstacles which caused the local planner to fail. A best-first search algorithm A* is used for graph search.

  8. Inverse Ising inference with correlated samples

    NASA Astrophysics Data System (ADS)

    Obermayer, Benedikt; Levine, Erel

    2014-12-01

    Correlations between two variables of a high-dimensional system can be indicative of an underlying interaction, but can also result from indirect effects. Inverse Ising inference is a method to distinguish one from the other. Essentially, the parameters of the least constrained statistical model are learned from the observed correlations such that direct interactions can be separated from indirect correlations. Among many other applications, this approach has been helpful for protein structure prediction, because residues which interact in the 3D structure often show correlated substitutions in a multiple sequence alignment. In this context, samples used for inference are not independent but share an evolutionary history on a phylogenetic tree. Here, we discuss the effects of correlations between samples on global inference. Such correlations could arise due to phylogeny but also via other slow dynamical processes. We present a simple analytical model to address the resulting inference biases, and develop an exact method accounting for background correlations in alignment data by combining phylogenetic modeling with an adaptive cluster expansion algorithm. We find that popular reweighting schemes are only marginally effective at removing phylogenetic bias, suggest a rescaling strategy that yields better results, and provide evidence that our conclusions carry over to the frequently used mean-field approach to the inverse Ising problem.

  9. Inverse statistical mechanics, lattice packings, and glasses

    NASA Astrophysics Data System (ADS)

    Marcotte, Etienne

    Computer simulation methods enable the investigation of systems and properties that are intractable by purely analytical or experimental approaches. Each chapter of this dissertation contains an application of simulation methods to solve complex physical problems consisting of interacting many-particle or many-spin systems. The problems studied in this dissertation can be divided up into the following two broad categories: inverse and forward problems. The inverse problems considered are those in which we construct an interaction potential such that the corresponding ground state is a targeted configuration. In Chapters 2 and 3, we devise convex pair-potential functions that result in low-coordinated ground states. Chapter 2 describes targeted ground states that are the square and honeycomb crystals, while in Chapter 3 the targeted ground state is the diamond crystal. Chapter 4 applies similar techniques to explicitly enumerate all unique ground states up to a given system size, for spin configurations that interact according to generalized isotropic Ising potentials with finite range. We also consider forward statistical-mechanical problems. In Chapter 5, we adapt a linear programming algorithm to find the densest lattice packings across Euclidean space dimensions. In Chapter 6, we demonstrate that for two different glass models a signature of the glass transition is apparent well before the transition temperature is reached. In both models, this signature appears as nonequilibrium length scales that grow upon supercooling.

  10. Impacts of decline harvest of country food on nutrient intake among Inuit in Arctic Canada: impact of climate change and possible adaptation plan

    PubMed Central

    Rosol, Renata; Powell-Hellyer, Stephanie; Chan, Hing Man

    2016-01-01

    Background The pervasive food insecurity and the diet transition away from local, nutrient-rich country foods present a public health challenge among Inuit living in the Canadian Arctic. While environmental factors such as climate change decreased the accessibility and availability of many country food species, new species were introduced into regions where they were previously unavailable. An adaptation such as turning to alternate country food species can be a viable solution to substitute for the nutrients provided by the declined food species. The objective of this study was to estimate the impact on nutrient intake using hypothetical scenarios that current commonly harvested country foods were reduced by 50%, and were replaced with alternate or new species. Methods Data collected during the 2007–2008 Inuit Health Survey from 36 Canadian Arctic communities spanning Nunavut, the Inuvialuit Settlement Region and Nunatsiavut were used. Results A 50% decline in consumption of fish, whale, ringed seals and birds (the food that was reported to be in decline) resulted in a significant decrease in essential nutrient intake. Possible substitute foods were identified but some nutrients such as zinc and especially vitamin D were most often found lacking in the alternative diet. Conclusions If the alternative species are not available or feasible, more expensive and less nutritionally dense store-bought foods may be sought. Given the superior quality of country foods and their association with food security, and Inuit cultural health and personal identity, developing skills and awareness for adaptation, promoting regional sharing networks, forming a co-management agency and continuing nutritional monitoring may potentially preserve the nutritional integrity of Inuit diet, and in turn their health and cultural survival. PMID:27388896

  11. Adaptation Planning to Minimize Damage to Road Infrastructure from Rising Groundwater Associated with Climate Change and Sea Level Rise in Coastal New Hampshire

    NASA Astrophysics Data System (ADS)

    Knott, J. F.; Jacobs, J. M.; Daniel, J.; Kirshen, P. H.

    2015-12-01

    Coastal communities with high population density and infrastructure close to the shoreline are vulnerable to the effects of climate change and sea level rise (SLR). In the northeast, annual precipitation has increased by more than 10-percent in the last 100 years and is projected to increase further in the future. In addition, sea level in coastal New Hampshire is projected to rise 1.2 to 2.0 meters by the year 2100 (New Hampshire Coastal Risks and Hazards Commission). Climate change vulnerability and adaptation studies have primarily focused on surface water flooding from SLR; however, little attention has been given to rising waters from beneath the ground surface. Groundwater in many coastal communities will rise with rising sea level which will likely have important consequences for water quality, the structural integrity of foundations and infrastructure, and the health of natural ecosystems in the coastal zone. In this study, we have constructed a regional groundwater flow model of coastal New Hampshire to investigate the effect of various climate change and SLR scenarios on groundwater levels, focusing on impacts to road infrastructure. Using LiDAR datasets and downscaled global climate predictions, we determined that the interaction of several hydrogeological factors resulted in distinct spatial patterns of groundwater rise that were not evident from simple models linking SLR and terrain. Furthermore, by loosely coupling the groundwater model to a hydraulic model for pavement systems, we were able to identify sections of roadways that will have compromised pavement performance due to rising groundwater intersecting the sublayers of these roadways. Our findings broadly suggest that adaptation strategies designed to counter the effects of climate change and SLR in coastal communities must consider potential damage from rising groundwater in addition to surface water impacts not only immediately along the coast but also at significant distances inland.

  12. Inverse solutions for electric and potential field imaging

    NASA Astrophysics Data System (ADS)

    Johnson, Christopher R.; MacLeod, Robert S.

    1993-08-01

    One of the fundamental problems in theoretical electrocardiography can be characterized by an inverse problem. In this paper, we present new methods for achieving better estimates of heart surface potential distributions in terms of torso potentials through an inverse procedure. First, an adaptive meshing algorithm is described which minimizes the error in the forward problem due to spatial discretization. We have found that since the inverse problem relies directly on the accuracy of the forward solution, adaptive meshing produces a more accurate inverse transfer matrix. Secondly, we introduce a new local regularization procedure. This method works by breaking the global transfer matrix into sub-matrices and performing regularization only on those sub-matrices which have large condition numbers. Furthermore, the regularization parameters are specifically 'tuned' for each sub-matrix using an a priori scheme based on the L-curve method. This local regularization method provides substantial increases in accuracy when compared to global regularization schemes. Finally, we present specific examples of the implementation of these schemes using models derived from magnetic resonance imaging data from a human subject.

  13. Nonlinear Dynamic Inversion Baseline Control Law: Architecture and Performance Predictions

    NASA Technical Reports Server (NTRS)

    Miller, Christopher J.

    2011-01-01

    A model reference dynamic inversion control law has been developed to provide a baseline control law for research into adaptive elements and other advanced flight control law components. This controller has been implemented and tested in a hardware-in-the-loop simulation; the simulation results show excellent handling qualities throughout the limited flight envelope. A simple angular momentum formulation was chosen because it can be included in the stability proofs for many basic adaptive theories, such as model reference adaptive control. Many design choices and implementation details reflect the requirements placed on the system by the nonlinear flight environment and the desire to keep the system as basic as possible to simplify the addition of the adaptive elements. Those design choices are explained, along with their predicted impact on the handling qualities.

  14. Fireplace adapters

    SciTech Connect

    Hunt, R.L.

    1983-12-27

    An adapter is disclosed for use with a fireplace. The stove pipe of a stove standing in a room to be heated may be connected to the flue of the chimney so that products of combustion from the stove may be safely exhausted through the flue and outwardly of the chimney. The adapter may be easily installed within the fireplace by removing the damper plate and fitting the adapter to the damper frame. Each of a pair of bolts has a portion which hooks over a portion of the damper frame and a threaded end depending from the hook portion and extending through a hole in the adapter. Nuts are threaded on the bolts and are adapted to force the adapter into a tight fit with the adapter frame.

  15. Megabase-scale inversion polymorphism in the wild ancestor of maize.

    PubMed

    Fang, Zhou; Pyhäjärvi, Tanja; Weber, Allison L; Dawe, R Kelly; Glaubitz, Jeffrey C; González, José de Jesus Sánchez; Ross-Ibarra, Claudia; Doebley, John; Morrell, Peter L; Ross-Ibarra, Jeffrey

    2012-07-01

    Chromosomal inversions are thought to play a special role in local adaptation, through dramatic suppression of recombination, which favors the maintenance of locally adapted alleles. However, relatively few inversions have been characterized in population genomic data. On the basis of single-nucleotide polymorphism (SNP) genotyping across a large panel of Zea mays, we have identified an ∼50-Mb region on the short arm of chromosome 1 where patterns of polymorphism are highly consistent with a polymorphic paracentric inversion that captures >700 genes. Comparison to other taxa in Zea and Tripsacum suggests that the derived, inverted state is present only in the wild Z. mays subspecies parviglumis and mexicana and is completely absent in domesticated maize. Patterns of polymorphism suggest that the inversion is ancient and geographically widespread in parviglumis. Cytological screens find little evidence for inversion loops, suggesting that inversion heterozygotes may suffer few crossover-induced fitness consequences. The inversion polymorphism shows evidence of adaptive evolution, including a strong altitudinal cline, a statistical association with environmental variables and phenotypic traits, and a skewed haplotype frequency spectrum for inverted alleles.

  16. Global inversion for anisotropy during full-waveform inversion

    NASA Astrophysics Data System (ADS)

    Debens, H. A.; Warner, M.; Umpleby, A.

    2015-12-01

    Full-waveform inversion (FWI) is a powerful tool for quantitative estimation of high-resolution high-fidelity models of subsurface seismic parameters, typically P-wave velocity. The solution to FWI's posed nonlinear inverse problem is obtained via an iterative series of linearized local updates to a start model, assuming this model lies within the basin of attraction to the global minimum. Thanks to many successful published applications to three-dimensional (3D) field datasets, its advance has been rapid and driven in large-part by the oil and gas industry. The consideration of seismic anisotropy during FWI is of vital importance, as it holds influence over both the kinematics and dynamics of seismic waveforms. If not appropriately taken into account then inadequacies in the anisotropy model are likely to manifest as significant error in the recovered velocity model. Conventionally, anisotropic FWI employs either an a priori anisotropy model, held fixed during FWI, or it uses a multi-parameter local inversion scheme to recover the anisotropy as part of the FWI; both of these methods can be problematic. Constructing an anisotropy model prior to FWI often involves intensive (and hence expensive) iterative procedures, such as travel-time tomography or moveout velocity analysis. On the other hand, introducing multiple parameters to FWI itself increases the complexity of what is already an underdetermined inverse problem. We propose that global rather than local FWI can be used to recover the long-wavelength acoustic anisotropy model, and that this can then be followed by more-conventional local FWI to recover the detailed model. We validate this approach using a full 3D field dataset, demonstrating that it avoids problems associated to crosstalk that can bedevil local inversion schemes, and reconciles well with in situ borehole measurements. Although our approach includes a global inversion for anisotropy, it is nonetheless affordable and practical for 3D field data.

  17. MHD Simulation of the Inverse Pinch Plasma Discharge

    SciTech Connect

    Esaulov, A; Bauer, B; Lindemuth, I; Makhin, V; Presura, R; Ryutov, D

    2004-07-01

    A wall confined plasma in an inverse pinch configuration holds potential as a plasma target for Magnetized Target Fusion (MTF) as well as the simple geometry to study wall-confined plasma. An experiment is planned to study the inverse pinch configuration using the Nevada Terawatt Facility (NTF) at the University of Nevada, Reno (UNR). The dynamics of the discharge formation have been analyzed using analytic models and numerical methods. Strong heating occurs by thermalization of directed energy when an outward moving current sheet (the inverse pinch effect) collides with the outer wall of the experimental chamber. Two dimensional MHD simulations show Rayleigh-Taylor and Richtmyer-Meshkov -like modes of instability, as expected because of the shock acceleration during plasma formation phase. The instabilities are not disruptive, but give rise to a mild level of turbulence. The conclusion from this work is that an interesting experiment relevant to wall confinement for MTF could be done using existing equipment at UNR.

  18. Inversion strategies for visco-acoustic waveform inversion

    NASA Astrophysics Data System (ADS)

    Kamei, R.; Pratt, R. G.

    2013-08-01

    Visco-acoustic waveform inversion can potentially yield quantitative images of the distribution of both velocity and the attenuation parameters from seismic data. Intrinsic P-wave attenuation has been of particular interest, but has also proven challenging. Frequency-domain inversion allows attenuation and velocity relations to be easily incorporated, and allows a natural multiscale approach. The Laplace-Fourier approach extends this to allow the natural damping of waveforms to enhance early arrivals. Nevertheless, simultaneous inversion of velocity and attenuation leads to significant `cross-talk' between the resulting images, reflecting a lack of parameter resolution and indicating the need for pre-conditioning and regularization of the inverse problem. We analyse the cross-talk issue by partitioning the inversion parameters into two classes; the velocity parameter class, and the attenuation parameter class. Both parameters are defined at a reference frequency, and a dispersion relation is assumed that describes these parameters at any other frequency. We formulate the model gradients at a forward modelling frequency, and convert them to the reference frequency by employing the Jacobian of the coordinate change represented by the dispersion relation. We show that at a given modelling frequency, the Fréchet derivatives corresponding to these two parameter classes differ only by a 90° phase shift, meaning that the magnitudes of resulting model updates will be unscaled, and will not reflect the expected magnitudes in realistic (Q-1 ≪ 1) media. Due to the lack of scaling, cross-talk will be enhanced by poor subsurface illumination, by errors in kinematics, and by data noise. To solve these issues, we introduce an attenuation scaling term (the inverse of a penalty term) that is used to pre-condition the gradient by controlling the magnitudes of the updates to the attenuation parameters. Initial results from a suite of synthetic cross-hole tests using a three

  19. Climate Variability and Change and Their Potential Health Effects in Small Island States: Information for Adaptation Planning in the Health Sector

    PubMed Central

    Ebi, Kristie L.; Lewis, Nancy D.; Corvalan, Carlos

    2006-01-01

    Small island states are likely the countries most vulnerable to climate variability and long-term climate change. Climate models suggest that small island states will experience warmer temperatures and changes in rainfall, soil moisture budgets, prevailing winds (speed and direction), and patterns of wave action. El Niño events likely will strengthen short-term and interannual climate variations. In addition, global mean sea level is projected to increase by 0.09–0.88 m by 2100, with variable effects on regional and local sea level. To better understand the potential human health consequences of these projected changes, a series of workshops and a conference organized by the World Health Organization, in partnership with the World Meteorological Organization and the United Nations Environment Programme, addressed the following issues: the current distribution and burden of climate-sensitive diseases in small island states, the potential future health impacts of climate variability and change, the interventions currently used to reduce the burden of climate-sensitive diseases, additional interventions that are needed to adapt to current and future health impacts, and the health implications of climate variability and change in other sectors. Information on these issues is synthesized and key recommendations are identified for improving the capacity of the health sector to anticipate and prepare for climate variability and change in small island states. PMID:17185291

  20. Climate variability and change and their potential health effects in small island states: information for adaptation planning in the health sector.

    PubMed

    Ebi, Kristie L; Lewis, Nancy D; Corvalan, Carlos

    2006-12-01

    Small island states are likely the countries most vulnerable to climate variability and longterm climate change. Climate models suggest that small island states will experience warmer temperatures and changes in rainfall, soil moisture budgets, prevailing winds (speed and direction), and patterns of wave action. El Niño events likely will strengthen shortterm and interannual climate variations. In addition, global mean sea level is projected to increase by 0.09-0.88 m by 2100, with variable effects on regional and local sea level. To better understand the potential human health consequences of these projected changes, a series of workshops and a conference organized by the World Health Organization, in partnership with the World Meteorological Organization and the United Nations Environment Programme, addressed the following issues: the current distribution and burden of climate-sensitive diseases in small island states, the potential future health impacts of climate variability and change, the interventions currently used to reduce the burden of climate-sensitive diseases, additional interventions that are needed to adapt to current and future health impacts, and the health implications of climate variability and change in other sectors. Information on these issues is synthesized and key recommendations are identified for improving the capacity of the health sector to anticipate and prepare for climate variability and change in small island states.

  1. Adaptive SPECT

    PubMed Central

    Barrett, Harrison H.; Furenlid, Lars R.; Freed, Melanie; Hesterman, Jacob Y.; Kupinski, Matthew A.; Clarkson, Eric; Whitaker, Meredith K.

    2008-01-01

    Adaptive imaging systems alter their data-acquisition configuration or protocol in response to the image information received. An adaptive pinhole single-photon emission computed tomography (SPECT) system might acquire an initial scout image to obtain preliminary information about the radiotracer distribution and then adjust the configuration or sizes of the pinholes, the magnifications, or the projection angles in order to improve performance. This paper briefly describes two small-animal SPECT systems that allow this flexibility and then presents a framework for evaluating adaptive systems in general, and adaptive SPECT systems in particular. The evaluation is in terms of the performance of linear observers on detection or estimation tasks. Expressions are derived for the ideal linear (Hotelling) observer and the ideal linear (Wiener) estimator with adaptive imaging. Detailed expressions for the performance figures of merit are given, and possible adaptation rules are discussed. PMID:18541485

  2. Thermoelectric properties of inverse opals

    NASA Astrophysics Data System (ADS)

    Mahan, G. D.; Poilvert, N.; Crespi, V. H.

    2016-02-01

    Rayleigh's method [Philos. Mag. Ser. 5 34, 481 (1892)] is used to solve for the classical thermoelectric equations in inverse opals. His theory predicts that in an inverse opal, with periodic holes, the Seebeck coefficient and the figure of merit are identical to that of the bulk material. We also provide a major revision to Rayleigh's method, in using the electrochemical potential as an important variable, instead of the electrostatic potential. We also show that in some cases, the thermal boundary resistance is important in the effective thermal conductivity.

  3. Population inversion by chirped pulses

    SciTech Connect

    Lu Tianshi

    2011-09-15

    In this paper, we analyze the condition for complete population inversion by a chirped pulse over a finite duration. The nonadiabatic transition probability is mapped in the two-dimensional parameter space of coupling strength and detuning amplitude. Asymptotic forms of the probability are derived by the interference of nonadiabatic transitions for sinusoidal and triangular pulses. The qualitative difference between the maps for the two types of pulses is accounted for. The map is used for the design of stable inversion pulses under specific accuracy thresholds.

  4. Multiphase inverse modeling: An Overview

    SciTech Connect

    Finsterle, S.

    1998-03-01

    Inverse modeling is a technique to derive model-related parameters from a variety of observations made on hydrogeologic systems, from small-scale laboratory experiments to field tests to long-term geothermal reservoir responses. If properly chosen, these observations contain information about the system behavior that is relevant to the performance of a geothermal field. Estimating model-related parameters and reducing their uncertainty is an important step in model development, because errors in the parameters constitute a major source of prediction errors. This paper contains an overview of inverse modeling applications using the ITOUGH2 code, demonstrating the possibilities and limitations of a formalized approach to the parameter estimation problem.

  5. Adaptive Computing.

    ERIC Educational Resources Information Center

    Harrell, William

    1999-01-01

    Provides information on various adaptive technology resources available to people with disabilities. (Contains 19 references, an annotated list of 129 websites, and 12 additional print resources.) (JOW)

  6. Contour adaptation.

    PubMed

    Anstis, Stuart

    2013-01-01

    It is known that adaptation to a disk that flickers between black and white at 3-8 Hz on a gray surround renders invisible a congruent gray test disk viewed afterwards. This is contrast adaptation. We now report that adapting simply to the flickering circular outline of the disk can have the same effect. We call this "contour adaptation." This adaptation does not transfer interocularly, and apparently applies only to luminance, not color. One can adapt selectively to only some of the contours in a display, making only these contours temporarily invisible. For instance, a plaid comprises a vertical grating superimposed on a horizontal grating. If one first adapts to appropriate flickering vertical lines, the vertical components of the plaid disappears and it looks like a horizontal grating. Also, we simulated a Cornsweet (1970) edge, and we selectively adapted out the subjective and objective contours of a Kanisza (1976) subjective square. By temporarily removing edges, contour adaptation offers a new technique to study the role of visual edges, and it demonstrates how brightness information is concentrated in edges and propagates from them as it fills in surfaces.

  7. Adaptation in Collaborative Governance Regimes

    NASA Astrophysics Data System (ADS)

    Emerson, Kirk; Gerlak, Andrea K.

    2014-10-01

    Adaptation and the adaptive capacity of human and environmental systems have been of central concern to natural and social science scholars, many of whom characterize and promote the need for collaborative cross-boundary systems that are seen as flexible and adaptive by definition. Researchers who study collaborative governance systems in the public administration, planning and policy literature have paid less attention to adaptive capacity specifically and institutional adaptation in general. This paper bridges the two literatures and finds four common dimensions of capacity, including structural arrangements, leadership, knowledge and learning, and resources. In this paper, we focus on institutional adaptation in the context of collaborative governance regimes and try to clarify and distinguish collaborative capacity from adaptive capacity and their contributions to adaptive action. We posit further that collaborative capacities generate associated adaptive capacities thereby enabling institutional adaptation within collaborative governance regimes. We develop these distinctions and linkages between collaborative and adaptive capacities with the help of an illustrative case study in watershed management within the National Estuary Program.

  8. Adaptation in collaborative governance regimes.

    PubMed

    Emerson, Kirk; Gerlak, Andrea K

    2014-10-01

    Adaptation and the adaptive capacity of human and environmental systems have been of central concern to natural and social science scholars, many of whom characterize and promote the need for collaborative cross-boundary systems that are seen as flexible and adaptive by definition. Researchers who study collaborative governance systems in the public administration, planning and policy literature have paid less attention to adaptive capacity specifically and institutional adaptation in general. This paper bridges the two literatures and finds four common dimensions of capacity, including structural arrangements, leadership, knowledge and learning, and resources. In this paper, we focus on institutional adaptation in the context of collaborative governance regimes and try to clarify and distinguish collaborative capacity from adaptive capacity and their contributions to adaptive action. We posit further that collaborative capacities generate associated adaptive capacities thereby enabling institutional adaptation within collaborative governance regimes. We develop these distinctions and linkages between collaborative and adaptive capacities with the help of an illustrative case study in watershed management within the National Estuary Program.

  9. EEG Theta Dynamics within Frontal and Parietal Cortices for Error Processing during Reaching Movements in a Prism Adaptation Study Altering Visuo-Motor Predictive Planning.

    PubMed

    Arrighi, Pieranna; Bonfiglio, Luca; Minichilli, Fabrizio; Cantore, Nicoletta; Carboncini, Maria Chiara; Piccotti, Emily; Rossi, Bruno; Andre, Paolo

    2016-01-01

    Modulation of frontal midline theta (fmθ) is observed during error commission, but little is known about the role of theta oscillations in correcting motor behaviours. We investigate EEG activity of healthy partipants executing a reaching task under variable degrees of prism-induced visuo-motor distortion and visual occlusion of the initial arm trajectory. This task introduces directional errors of different magnitudes. The discrepancy between predicted and actual movement directions (i.e. the error), at the time when visual feedback (hand appearance) became available, elicits a signal that triggers on-line movement correction. Analysis were performed on 25 EEG channels. For each participant, the median value of the angular error of all reaching trials was used to partition the EEG epochs into high- and low-error conditions. We computed event-related spectral perturbations (ERSP) time-locked either to visual feedback or to the onset of movement correction. ERSP time-locked to the onset of visual feedback showed that fmθ increased in the high- but not in the low-error condition with an approximate time lag of 200 ms. Moreover, when single epochs were sorted by the degree of motor error, fmθ started to increase when a certain level of error was exceeded and, then, scaled with error magnitude. When ERSP were time-locked to the onset of movement correction, the fmθ increase anticipated this event with an approximate time lead of 50 ms. During successive trials, an error reduction was observed which was associated with indices of adaptations (i.e., aftereffects) suggesting the need to explore if theta oscillations may facilitate learning. To our knowledge this is the first study where the EEG signal recorded during reaching movements was time-locked to the onset of the error visual feedback. This allowed us to conclude that theta oscillations putatively generated by anterior cingulate cortex activation are implicated in error processing in semi-naturalistic motor

  10. EEG Theta Dynamics within Frontal and Parietal Cortices for Error Processing during Reaching Movements in a Prism Adaptation Study Altering Visuo-Motor Predictive Planning

    PubMed Central

    Bonfiglio, Luca; Minichilli, Fabrizio; Cantore, Nicoletta; Carboncini, Maria Chiara; Piccotti, Emily; Rossi, Bruno

    2016-01-01

    Modulation of frontal midline theta (fmθ) is observed during error commission, but little is known about the role of theta oscillations in correcting motor behaviours. We investigate EEG activity of healthy partipants executing a reaching task under variable degrees of prism-induced visuo-motor distortion and visual occlusion of the initial arm trajectory. This task introduces directional errors of different magnitudes. The discrepancy between predicted and actual movement directions (i.e. the error), at the time when visual feedback (hand appearance) became available, elicits a signal that triggers on-line movement correction. Analysis were performed on 25 EEG channels. For each participant, the median value of the angular error of all reaching trials was used to partition the EEG epochs into high- and low-error conditions. We computed event-related spectral perturbations (ERSP) time-locked either to visual feedback or to the onset of movement correction. ERSP time-locked to the onset of visual feedback showed that fmθ increased in the high- but not in the low-error condition with an approximate time lag of 200 ms. Moreover, when single epochs were sorted by the degree of motor error, fmθ started to increase when a certain level of error was exceeded and, then, scaled with error magnitude. When ERSP were time-locked to the onset of movement correction, the fmθ increase anticipated this event with an approximate time lead of 50 ms. During successive trials, an error reduction was observed which was associated with indices of adaptations (i.e., aftereffects) suggesting the need to explore if theta oscillations may facilitate learning. To our knowledge this is the first study where the EEG signal recorded during reaching movements was time-locked to the onset of the error visual feedback. This allowed us to conclude that theta oscillations putatively generated by anterior cingulate cortex activation are implicated in error processing in semi-naturalistic motor

  11. Inversions. Popular Lectures in Mathematics.

    ERIC Educational Resources Information Center

    Bakel'man, I. Ya

    Inversions are transformations of geometric figures, under which straight lines may be mapped to circles, and conversely. The use of such mapping allows development of a unified method of solution for many of the problems of elementary geometry, especially those concerning constructions and "pencils" of curves. This book discusses the inversion…

  12. Climate adaptation

    NASA Astrophysics Data System (ADS)

    Kinzig, Ann P.

    2015-03-01

    This paper is intended as a brief introduction to climate adaptation in a conference devoted otherwise to the physics of sustainable energy. Whereas mitigation involves measures to reduce the probability of a potential event, such as climate change, adaptation refers to actions that lessen the impact of climate change. Mitigation and adaptation differ in other ways as well. Adaptation does not necessarily have to be implemented immediately to be effective; it only needs to be in place before the threat arrives. Also, adaptation does not necessarily require global, coordinated action; many effective adaptation actions can be local. Some urban communities, because of land-use change and the urban heat-island effect, currently face changes similar to some expected under climate change, such as changes in water availability, heat-related morbidity, or changes in disease patterns. Concern over those impacts might motivate the implementation of measures that would also help in climate adaptation, despite skepticism among some policy makers about anthropogenic global warming. Studies of ancient civilizations in the southwestern US lends some insight into factors that may or may not be important to successful adaptation.

  13. Complex Patterns of Local Adaptation in Teosinte

    PubMed Central

    Pyhäjärvi, Tanja; Hufford, Matthew B.; Mezmouk, Sofiane; Ross-Ibarra, Jeffrey

    2013-01-01

    Populations of widely distributed species encounter and must adapt to local environmental conditions. However, comprehensive characterization of the genetic basis of adaptation is demanding, requiring genome-wide genotype data, multiple sampled populations, and an understanding of population structure and potential selection pressures. Here, we used single-nucleotide polymorphism genotyping and data on numerous environmental variables to describe the genetic basis of local adaptation in 21 populations of teosinte, the wild ancestor of maize. We found complex hierarchical genetic structure created by altitude, dispersal events, and admixture among subspecies, which complicated identification of locally beneficial alleles. Patterns of linkage disequilibrium revealed four large putative inversion polymorphisms showing clinal patterns of frequency. Population differentiation and environmental correlations suggest that both inversions and intergenic polymorphisms are involved in local adaptation. PMID:23902747

  14. Applications of inverse pattern projection

    NASA Astrophysics Data System (ADS)

    Li, Wansong; Bothe, Thorsten; Kalms, Michael K.; von Kopylow, Christoph; Jueptner, Werner P. O.

    2003-05-01

    Fast and robust 3D quality control as well as fast deformation measurement is of particular importance for industrial inspection. Additionally a direct response about measured properties is desired. Therefore, robust optical techniques are needed which use as few images as possible for measurement and visualize results in an efficient way. One promising technique for this aim is the inverse pattern projection which has the following advantages: The technique codes the information of a preceding measurement into the projected inverse pattern. Thus, it is possible to do differential measurements using only one camera frame for each state. Additionally, the results are optimized straight fringes for sampling which are independent of the object curvature. The hardware needs are low as just a programmable projector and a standard camera are necessary. The basic idea of inverse pattern projection, necessary algorithms and found optimizations are demonstrated, roughly. Evaluation techniques were found to preserve a high quality phase measurement under imperfect conditions. The different application fields can be sorted out by the type of pattern used for inverse projection. We select two main topics for presentation. One is the incremental (one image per state) deformation measurement which is a promising technique for high speed deformation measurements. A video series of a wavering flag with projected inverse pattern was evaluated to show the complete deformation series. The other application is the optical feature marking (augmented reality) that allows to map any measured result directly onto the object under investigation. Any properties can be visualized directly on the object"s surface which makes inspections easier than with use of a separated indicating device. The general ability to straighten any kind of information on 3D surfaces is shown while preserving an exact mapping of camera image and object parts. In many cases this supersedes an additional monitor to

  15. Institutional Long-Range Planning.

    ERIC Educational Resources Information Center

    Bolin, John G.

    This booklet presents a general outline for conducting a long-range planning study that can be adapted for use by any institution of higher education. The basic components of an effective long-range plan should include: (1) purposes of the plan, which define the scope of the study and provide the setting in which it will be initiated; (2) a set of…

  16. SU-E-J-151: Dosimetric Evaluation of DIR Mapped Contours for Image Guided Adaptive Radiotherapy with 4D Cone-Beam CT

    SciTech Connect

    Balik, S; Weiss, E; Williamson, J; Hugo, G; Jan, N; Zhang, L; Roman, N; Christensen, G

    2014-06-01

    Purpose: To estimate dosimetric errors resulting from using contours deformably mapped from planning CT to 4D cone beam CT (CBCT) images for image-guided adaptive radiotherapy of locally advanced non-small cell lung cancer (NSCLC). Methods: Ten locally advanced non-small cell lung cancer (NSCLC) patients underwent one planning 4D fan-beam CT (4DFBCT) and weekly 4DCBCT scans. Multiple physicians delineated the gross tumor volume (GTV) and normal structures in planning CT images and only GTV in CBCT images. Manual contours were mapped from planning CT to CBCTs using small deformation, inverse consistent linear elastic (SICLE) algorithm for two scans in each patient. Two physicians reviewed and rated the DIR-mapped (auto) and manual GTV contours as clinically acceptable (CA), clinically acceptable after minor modification (CAMM) and unacceptable (CU). Mapped normal structures were visually inspected and corrected if necessary, and used to override tissue density for dose calculation. CTV (6mm expansion of GTV) and PTV (5mm expansion of CTV) were created. VMAT plans were generated using the DIR-mapped contours to deliver 66 Gy in 33 fractions with 95% and 100% coverage (V66) to PTV and CTV, respectively. Plan evaluation for V66 was based on manual PTV and CTV contours. Results: Mean PTV V66 was 84% (range 75% – 95%) and mean CTV V66 was 97% (range 93% – 100%) for CAMM scored plans (12 plans); and was 90% (range 80% – 95%) and 99% (range 95% – 100%) for CA scored plans (7 plans). The difference in V66 between CAMM and CA was significant for PTV (p = 0.03) and approached significance for CTV (p = 0.07). Conclusion: The quality of DIR-mapped contours directly impacted the plan quality for 4DCBCT-based adaptation. Larger safety margins may be needed when planning with auto contours for IGART with 4DCBCT images. Reseach was supported by NIH P01CA116602.

  17. Non-linearity in Bayesian 1-D magnetotelluric inversion

    NASA Astrophysics Data System (ADS)

    Guo, Rongwen; Dosso, Stan E.; Liu, Jianxin; Dettmer, Jan; Tong, Xiaozhong

    2011-05-01

    This paper applies a Bayesian approach to examine non-linearity for the 1-D magnetotelluric (MT) inverse problem. In a Bayesian formulation the posterior probability density (PPD), which combines data and prior information, is interpreted in terms of parameter estimates and uncertainties, which requires optimizing and integrating the PPD. Much work on 1-D MT inversion has been based on (approximate) linearized solutions, but more recently fully non-linear (numerical) approaches have been applied. This paper directly compares results of linearized and non-linear uncertainty estimation for 1-D MT inversion; to do so, advanced methods for both approaches are applied. In the non-linear formulation used here, numerical optimization is carried out using an adaptive-hybrid algorithm. Numerical integration applies Metropolis-Hastings sampling, rotated to a principal-component parameter space for efficient sampling of correlated parameters, and employing non-unity sampling temperatures to ensure global sampling. Since appropriate model parametrizations are generally not known a priori, both under- and overparametrized approaches are considered. For underparametrization, the Bayesian information criterion is applied to determine the number of layers consistent with the resolving power of the data. For overparametrization, prior information is included which favours simple structure in a manner similar to regularized inversion. The data variance and/or trade-off parameter regulating data and prior information are treated in several ways, including applying fixed optimal estimates (an empirical Bayesian approach) or including them as hyperparameters in the sampling (hierarchical Bayesian). The latter approach has the benefit of accounting for the uncertainty in the hyperparameters in estimating model parameter uncertainties. Non-linear and linearized inversion results are compared for synthetic test cases and for the measured COPROD1 MT data by considering marginal probability

  18. Multiple and diverse structural changes affect the breakpoint regions of polymorphic inversions across the Drosophila genus

    PubMed Central

    Puerma, Eva; Orengo, Dorcas J.; Aguadé, Montserrat

    2016-01-01

    Chromosomal polymorphism is widespread in the Drosophila genus, with extensive evidence supporting its adaptive character in diverse species. Moreover, inversions are the major contributors to the genus chromosomal evolution. The molecular characterization of a reduced number of polymorphic inversion breakpoints in Drosophila melanogaster and Drosophila subobscura supports that their inversions would have mostly originated through a mechanism that generates duplications —staggered double-strand breaks— and has thus the potential to contribute to their adaptive character. There is also evidence for inversion breakpoint reuse at different time scales. Here, we have characterized the breakpoints of two inversions of D. subobscura —O4 and O8— involved in complex arrangements that are frequent in the warm parts of the species distribution area. The duplications detected at their breakpoints are consistent with their origin through the staggered-break mechanism, which further supports it as the prevalent mechanism in D. subobscura. The comparative analysis of inversions breakpoint regions across the Drosophila genus has revealed several genes affected by multiple disruptions due not only to inversions but also to single-gene transpositions and duplications. PMID:27782210

  19. Estimating stellar mean density through seismic inversions

    NASA Astrophysics Data System (ADS)

    Reese, D. R.; Marques, J. P.; Goupil, M. J.; Thompson, M. J.; Deheuvels, S.

    2012-03-01

    Context. Determining the mass of stars is crucial both for improving stellar evolution theory and for characterising exoplanetary systems. Asteroseismology offers a promising way for estimating the stellar mean density. When combined with accurate radii determinations, such as are expected from Gaia, this yields accurate stellar masses. The main difficulty is finding the best way to extract the mean density of a star from a set of observed frequencies. Aims: We seek to establish a new method for estimating the stellar mean density, which combines the simplicity of a scaling law while providing the accuracy of an inversion technique. Methods: We provide a framework in which to construct and evaluate kernel-based linear inversions that directly yield the mean density of a star. We then describe three different inversion techniques (SOLA and two scaling laws) and apply them to the Sun, several test cases and three stars, α Cen B, HD 49933 and HD 49385, two of which are observed by CoRoT. Results: The SOLA (subtractive optimally localised averages) approach and the scaling law based on the surface correcting technique described by Kjeldsen et al. (2008, ApJ, 683, L175) yield comparable results that can reach an accuracy of 0.5% and are better than scaling the large frequency separation. The reason for this is that the averaging kernels from the two first methods are comparable in quality and are better than what is obtained with the large frequency separation. It is also shown that scaling the large frequency separation is more sensitive to near-surface effects, but is much less affected by an incorrect mode identification. As a result, one can identify pulsation modes by looking for an ℓ and n assignment which provides the best agreement between the results from the large frequency separation and those from one of the two other methods. Non-linear effects are also discussed, as is the effects of mixed modes. In particular, we show that mixed modes bring little

  20. Classifying climate change adaptation frameworks

    NASA Astrophysics Data System (ADS)

    Armstrong, Jennifer

    2014-05-01

    Complex socio-ecological demographics are factors that must be considered when addressing adaptation to the potential effects of climate change. As such, a suite of deployable climate change adaptation frameworks is necessary. Multiple frameworks that are required to communicate the risks of climate change and facilitate adaptation. Three principal adaptation frameworks have emerged from the literature; Scenario - Led (SL), Vulnerability - Led (VL) and Decision - Centric (DC). This study aims to identify to what extent these adaptation frameworks; either, planned or deployed are used in a neighbourhood vulnerable to climate change. This work presents a criterion that may be used as a tool for identifying the hallmarks of adaptation frameworks and thus enabling categorisation of projects. The study focussed on the coastal zone surrounding the Sizewell nuclear power plant in Suffolk in the UK. An online survey was conducted identifying climate change adaptation projects operating in the study area. This inventory was analysed to identify the hallmarks of each adaptation project; Levels of dependency on climate model information, Metrics/units of analysis utilised, Level of demographic knowledge, Level of stakeholder engagement, Adaptation implementation strategies and Scale of adapta