Development of the Free Time Motivation Scale for Adolescents.

ERIC Educational Resources Information Center

Baldwin, Cheryl K.; Caldwell, Linda L.

2003-01-01

Developed a self-report measure of adolescent free time motivation based in self-determination theory, using data from 634 seventh graders. The scale measured five forms of motivation (amotivation, external, introjected, identified, and intrinsic motivation). Examination of each of the subscales indicated minimally acceptable levels of fit. The…

An efficient graph theory based method to identify every minimal reaction set in a metabolic network

PubMed Central

2014-01-01

Background Development of cells with minimal metabolic functionality is gaining importance due to their efficiency in producing chemicals and fuels. Existing computational methods to identify minimal reaction sets in metabolic networks are computationally expensive. Further, they identify only one of the several possible minimal reaction sets. Results In this paper, we propose an efficient graph theory based recursive optimization approach to identify all minimal reaction sets. Graph theoretical insights offer systematic methods to not only reduce the number of variables in math programming and increase its computational efficiency, but also provide efficient ways to find multiple optimal solutions. The efficacy of the proposed approach is demonstrated using case studies from Escherichia coli and Saccharomyces cerevisiae. In case study 1, the proposed method identified three minimal reaction sets each containing 38 reactions in Escherichia coli central metabolic network with 77 reactions. Analysis of these three minimal reaction sets revealed that one of them is more suitable for developing minimal metabolism cell compared to other two due to practically achievable internal flux distribution. In case study 2, the proposed method identified 256 minimal reaction sets from the Saccharomyces cerevisiae genome scale metabolic network with 620 reactions. The proposed method required only 4.5 hours to identify all the 256 minimal reaction sets and has shown a significant reduction (approximately 80%) in the solution time when compared to the existing methods for finding minimal reaction set. Conclusions Identification of all minimal reactions sets in metabolic networks is essential since different minimal reaction sets have different properties that effect the bioprocess development. The proposed method correctly identified all minimal reaction sets in a both the case studies. The proposed method is computationally efficient compared to other methods for finding minimal reaction sets and useful to employ with genome-scale metabolic networks. PMID:24594118

Construction schedules slack time minimizing

NASA Astrophysics Data System (ADS)

Krzemiński, Michał

2017-07-01

The article presents two copyright models for minimizing downtime working brigades. Models have been developed for construction schedules performed using the method of work uniform. Application of flow shop models is possible and useful for the implementation of large objects, which can be divided into plots. The article also presents a condition describing gives which model should be used, as well as a brief example of optimization schedule. The optimization results confirm the legitimacy of the work on the newly-developed models.

A multimedia electronic patient record (ePR) system for image-assisted minimally invasive spinal surgery.

PubMed

Documet, Jorge; Le, Anh; Liu, Brent; Chiu, John; Huang, H K

2010-05-01

This paper presents the concept of bridging the gap between diagnostic images and image-assisted surgical treatment through the development of a one-stop multimedia electronic patient record (ePR) system that manages and distributes the real-time multimodality imaging and informatics data that assists the surgeon during all clinical phases of the operation from planning Intra-Op to post-care follow-up. We present the concept of this multimedia ePR for surgery by first focusing on image-assisted minimally invasive spinal surgery as a clinical application. Three clinical phases of minimally invasive spinal surgery workflow in Pre-Op, Intra-Op, and Post-Op are discussed. The ePR architecture was developed based on the three-phased workflow, which includes the Pre-Op, Intra-Op, and Post-Op modules and four components comprising of the input integration unit, fault-tolerant gateway server, fault-tolerant ePR server, and the visualization and display. A prototype was built and deployed to a minimally invasive spinal surgery clinical site with user training and support for daily use. A step-by-step approach was introduced to develop a multimedia ePR system for imaging-assisted minimally invasive spinal surgery that includes images, clinical forms, waveforms, and textual data for planning the surgery, two real-time imaging techniques (digital fluoroscopic, DF) and endoscope video images (Endo), and more than half a dozen live vital signs of the patient during surgery. Clinical implementation experiences and challenges were also discussed.

Study to Minimize Learning Progress Differences in Software Learning Class Using PLITAZ System

ERIC Educational Resources Information Center

Dong, Jian-Jie; Hwang, Wu-Yuin

2012-01-01

This study developed a system using two-phased strategies called "Pause Lecture, Instant Tutor-Tutee Match, and Attention Zone" (PLITAZ). This system was used to help solve learning challenges and to minimize learning progress differences in a software learning class. During a teacher's lecture time, students were encouraged to anonymously express…

A minimization principle for the description of modes associated with finite-time instabilities

PubMed Central

Babaee, H.

2016-01-01

We introduce a minimization formulation for the determination of a finite-dimensional, time-dependent, orthonormal basis that captures directions of the phase space associated with transient instabilities. While these instabilities have finite lifetime, they can play a crucial role either by altering the system dynamics through the activation of other instabilities or by creating sudden nonlinear energy transfers that lead to extreme responses. However, their essentially transient character makes their description a particularly challenging task. We develop a minimization framework that focuses on the optimal approximation of the system dynamics in the neighbourhood of the system state. This minimization formulation results in differential equations that evolve a time-dependent basis so that it optimally approximates the most unstable directions. We demonstrate the capability of the method for two families of problems: (i) linear systems, including the advection–diffusion operator in a strongly non-normal regime as well as the Orr–Sommerfeld/Squire operator, and (ii) nonlinear problems, including a low-dimensional system with transient instabilities and the vertical jet in cross-flow. We demonstrate that the time-dependent subspace captures the strongly transient non-normal energy growth (in the short-time regime), while for longer times the modes capture the expected asymptotic behaviour. PMID:27118900

Fastener Capture Plate Technology to Contain On-Orbit Debris

NASA Technical Reports Server (NTRS)

Eisenhower, Kevin

2010-01-01

The Fastener Capture Plate technology was developed to solve the problem of capturing loose hardware and small fasteners, items that were not originally intended to be disengaged in microgravity, thus preventing them from becoming space debris. This technology was incorporated into astronaut tools designed and successfully used on NASA s Hubble Space Telescope Servicing Mission #4. The technology s ultimate benefit is that it allows a very time-efficient method for disengaging fasteners and removing hardware while minimizing the chances of losing parts or generating debris. The technology aims to simplify the manual labor required of the operator. It does so by optimizing visibility and access to the work site and minimizing the operator's need to be concerned with debris while performing the operations. It has a range of unique features that were developed to minimize task time, as well as maximize the ease and confidence of the astronaut operator. This paper describes the technology and the astronaut tools developed specifically for a complicated on-orbit repair, and it includes photographs of the hardware being used in outer space.

Assessing and minimizing contamination in time of flight based validation data

NASA Astrophysics Data System (ADS)

Lennox, Kristin P.; Rosenfield, Paul; Blair, Brenton; Kaplan, Alan; Ruz, Jaime; Glenn, Andrew; Wurtz, Ronald

2017-10-01

Time of flight experiments are the gold standard method for generating labeled training and testing data for the neutron/gamma pulse shape discrimination problem. As the popularity of supervised classification methods increases in this field, there will also be increasing reliance on time of flight data for algorithm development and evaluation. However, time of flight experiments are subject to various sources of contamination that lead to neutron and gamma pulses being mislabeled. Such labeling errors have a detrimental effect on classification algorithm training and testing, and should therefore be minimized. This paper presents a method for identifying minimally contaminated data sets from time of flight experiments and estimating the residual contamination rate. This method leverages statistical models describing neutron and gamma travel time distributions and is easily implemented using existing statistical software. The method produces a set of optimal intervals that balance the trade-off between interval size and nuisance particle contamination, and its use is demonstrated on a time of flight data set for Cf-252. The particular properties of the optimal intervals for the demonstration data are explored in detail.

Minimal-change nephropathy and malignant thymoma.

PubMed

Varsano, S; Bruderman, I; Bernheim, J L; Rathaus, M; Griffel, B

1980-05-01

A 56-year-old man had fever, precordial pain, and a mediastinal mass. The mass disappeared two months later and the patient remained asymptomatic for 2 1/2 years. At that time a full-blown nephrotic syndrome developed, with minimal-change glomerulopathy. The chest x-ray film showed the reappearance of a giant mediastinal mass. On biopsy of the mass, malignant thymoma was diagnosed. Association between minimal-change disease and Hodgkin's disease is well known, while the association with malignant thymoma has not been previously reported. The relationship between malignant thymoma and minimal-change disease is discussed, and a possible pathogenic mechanism involving cell-mediated immunity is proposed.

Finite element procedures for time-dependent convection-diffusion-reaction systems

NASA Technical Reports Server (NTRS)

Tezduyar, T. E.; Park, Y. J.; Deans, H. A.

1988-01-01

New finite element procedures based on the streamline-upwind/Petrov-Galerkin formulations are developed for time-dependent convection-diffusion-reaction equations. These procedures minimize spurious oscillations for convection-dominated and reaction-dominated problems. The results obtained for representative numerical examples are accurate with minimal oscillations. As a special application problem, the single-well chemical tracer test (a procedure for measuring oil remaining in a depleted field) is simulated numerically. The results show the importance of temperature effects on the interpreted value of residual oil saturation from such tests.

Optimal Black Start Resource Allocation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qiu, Feng; Wang, Jianhui; Chen, Chen

The restoration of the bulk power system after a partial or complete blackout relies on black-start (BS) resources. To prepare for system restoration, it is important to procure the right amount of BS resources at the right locations in the grid so that the total restoration time can be minimized. Achieving this goal requires that resource procurement planning takes the restoration process into account. In this study, we integrate the BS resource procurement decision with a restoration planning model and develop an optimization model that produces a minimal cost procurement plan that satisfies the restoration time requirement.

Real time selective harmonic minimization for multilevel inverters using genetic algorithm and artifical neural network angle generation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Filho, Faete J; Tolbert, Leon M; Ozpineci, Burak

2012-01-01

The work developed here proposes a methodology for calculating switching angles for varying DC sources in a multilevel cascaded H-bridges converter. In this approach the required fundamental is achieved, the lower harmonics are minimized, and the system can be implemented in real time with low memory requirements. Genetic algorithm (GA) is the stochastic search method to find the solution for the set of equations where the input voltages are the known variables and the switching angles are the unknown variables. With the dataset generated by GA, an artificial neural network (ANN) is trained to store the solutions without excessive memorymore » storage requirements. This trained ANN then senses the voltage of each cell and produces the switching angles in order to regulate the fundamental at 120 V and eliminate or minimize the low order harmonics while operating in real time.« less

A multimedia Electronic Patient Record (ePR) system for Image-Assisted Minimally Invasive Spinal Surgery

PubMed Central

Documet, Jorge; Le, Anh; Liu, Brent; Chiu, John; Huang, HK

2009-01-01

Purpose This paper presents the concept of bridging the gap between diagnostic images and image-assisted surgical treatment through the development of a one-stop multimedia electronic patient record (ePR) system that manages and distributes the real-time multimodality imaging and informatics data that assists the surgeon during all clinical phases of the operation from planning Intra-Op to post-care follow-up. We present the concept of this multimedia ePR for surgery by first focusing on Image-Assisted Minimally Invasive Spinal Surgery as a clinical application. Methods Three clinical Phases of Minimally Invasive Spinal Surgery workflow in Pre-Op, Intra-Op, and Post Op are discussed. The ePR architecture was developed based on the three-phased workflow, which includes the Pre-Op, Intra-Op, and Post-Op modules and four components comprising of the input integration unit, fault-tolerant gateway server, fault-tolerant ePR server, and the visualization and display. A prototype was built and deployed to a Minimally Invasive Spinal Surgery clinical site with user training and support for daily use. Summary A step-by step approach was introduced to develop a multi-media ePR system for Imaging-Assisted Minimally Invasive Spinal Surgery that includes images, clinical forms, waveforms, and textual data for planning the surgery, two real-time imaging techniques (digital fluoroscopic, DF) and endoscope video images (Endo), and more than half a dozen live vital signs of the patient during surgery. Clinical implementation experiences and challenges were also discussed. PMID:20033507

Application of quadratic optimization to supersonic inlet control.

NASA Technical Reports Server (NTRS)

Lehtinen, B.; Zeller, J. R.

1972-01-01

This paper describes the application of linear stochastic optimal control theory to the design of the control system for the air intake, the inlet, of a supersonic air-breathing propulsion system. The controls must maintain a stable inlet shock position in the presence of random airflow disturbances and prevent inlet unstart. Two different linear time invariant controllers are developed. One is designed to minimize a nonquadratic index, the expected frequency of inlet unstart, and the other is designed to minimize the mean square value of inlet shock motion. The quadratic equivalence principle is used to obtain a linear controller that minimizes the nonquadratic index. The two controllers are compared on the basis of unstart prevention, control effort requirements, and frequency response. It is concluded that while controls designed to minimize unstarts are desirable in that the index minimized is physically meaningful, computation time required is longer than for the minimum mean square shock position approach. The simpler minimum mean square shock position solution produced expected unstart frequency values which were not significantly larger than those of the nonquadratic solution.

Two time scale output feedback regulation for ill-conditioned systems

NASA Technical Reports Server (NTRS)

Calise, A. J.; Moerder, D. D.

1986-01-01

Issues pertaining to the well-posedness of a two time scale approach to the output feedback regulator design problem are examined. An approximate quadratic performance index which reflects a two time scale decomposition of the system dynamics is developed. It is shown that, under mild assumptions, minimization of this cost leads to feedback gains providing a second-order approximation of optimal full system performance. A simplified approach to two time scale feedback design is also developed, in which gains are separately calculated to stabilize the slow and fast subsystem models. By exploiting the notion of combined control and observation spillover suppression, conditions are derived assuring that these gains will stabilize the full-order system. A sequential numerical algorithm is described which obtains output feedback gains minimizing a broad class of performance indices, including the standard LQ case. It is shown that the algorithm converges to a local minimum under nonrestrictive assumptions. This procedure is adapted to and demonstrated for the two time scale design formulations.

Optimal Rate Schedules with Data Sharing in Energy Harvesting Communication Systems.

PubMed

Wu, Weiwei; Li, Huafan; Shan, Feng; Zhao, Yingchao

2017-12-20

Despite the abundant research on energy-efficient rate scheduling polices in energy harvesting communication systems, few works have exploited data sharing among multiple applications to further enhance the energy utilization efficiency, considering that the harvested energy from environments is limited and unstable. In this paper, to overcome the energy shortage of wireless devices at transmitting data to a platform running multiple applications/requesters, we design rate scheduling policies to respond to data requests as soon as possible by encouraging data sharing among data requests and reducing the redundancy. We formulate the problem as a transmission completion time minimization problem under constraints of dynamical data requests and energy arrivals. We develop offline and online algorithms to solve this problem. For the offline setting, we discover the relationship between two problems: the completion time minimization problem and the energy consumption minimization problem with a given completion time. We first derive the optimal algorithm for the min-energy problem and then adopt it as a building block to compute the optimal solution for the min-completion-time problem. For the online setting without future information, we develop an event-driven online algorithm to complete the transmission as soon as possible. Simulation results validate the efficiency of the proposed algorithm.

Optimal Rate Schedules with Data Sharing in Energy Harvesting Communication Systems

PubMed Central

Wu, Weiwei; Li, Huafan; Shan, Feng; Zhao, Yingchao

2017-01-01

Despite the abundant research on energy-efficient rate scheduling polices in energy harvesting communication systems, few works have exploited data sharing among multiple applications to further enhance the energy utilization efficiency, considering that the harvested energy from environments is limited and unstable. In this paper, to overcome the energy shortage of wireless devices at transmitting data to a platform running multiple applications/requesters, we design rate scheduling policies to respond to data requests as soon as possible by encouraging data sharing among data requests and reducing the redundancy. We formulate the problem as a transmission completion time minimization problem under constraints of dynamical data requests and energy arrivals. We develop offline and online algorithms to solve this problem. For the offline setting, we discover the relationship between two problems: the completion time minimization problem and the energy consumption minimization problem with a given completion time. We first derive the optimal algorithm for the min-energy problem and then adopt it as a building block to compute the optimal solution for the min-completion-time problem. For the online setting without future information, we develop an event-driven online algorithm to complete the transmission as soon as possible. Simulation results validate the efficiency of the proposed algorithm. PMID:29261135

OxMaR: open source free software for online minimization and randomization for clinical trials.

PubMed

O'Callaghan, Christopher A

2014-01-01

Minimization is a valuable method for allocating participants between the control and experimental arms of clinical studies. The use of minimization reduces differences that might arise by chance between the study arms in the distribution of patient characteristics such as gender, ethnicity and age. However, unlike randomization, minimization requires real time assessment of each new participant with respect to the preceding distribution of relevant participant characteristics within the different arms of the study. For multi-site studies, this necessitates centralized computational analysis that is shared between all study locations. Unfortunately, there is no suitable freely available open source or free software that can be used for this purpose. OxMaR was developed to enable researchers in any location to use minimization for patient allocation and to access the minimization algorithm using any device that can connect to the internet such as a desktop computer, tablet or mobile phone. The software is complete in itself and requires no special packages or libraries to be installed. It is simple to set up and run over the internet using online facilities which are very low cost or even free to the user. Importantly, it provides real time information on allocation to the study lead or administrator and generates real time distributed backups with each allocation. OxMaR can readily be modified and customised and can also be used for standard randomization. It has been extensively tested and has been used successfully in a low budget multi-centre study. Hitherto, the logistical difficulties involved in minimization have precluded its use in many small studies and this software should allow more widespread use of minimization which should lead to studies with better matched control and experimental arms. OxMaR should be particularly valuable in low resource settings.

Posting behaviour patterns in an online smoking cessation social network: implications for intervention design and development.

PubMed

Healey, Benjamin; Hoek, Janet; Edwards, Richard

2014-01-01

Online Cessation Support Networks (OCSNs) are associated with increased quit success rates, but few studies have examined their use over time. We identified usage patterns in New Zealand's largest OCSN over two years and explored implications for OCSN intervention design and evaluation. We analysed metadata relating to 133,096 OCSN interactions during 2011 and 2012. Metrics covered aggregate network activity, user posting activity and longevity, and between-user commenting. Binary logistic regression models were estimated to investigate the feasibility of predicting low user engagement using early interaction data. Repeating periodic peaks and troughs in aggregate activity related not only to seasonality (e.g., New Year), but also to day of the week. Out of 2,062 unique users, 69 Highly Engaged Users (180+ interactions each) contributed 69% of all OCSN interactions in 2012 compared to 1.3% contributed by 864 Minimally Engaged Users (< = 2 items each). The proportion of Highly Engaged Users increased with network growth between 2011 and 2012 (with marginal significance), but the proportion of Minimally Engaged Users did not decline substantively. First week interaction data enabled identification of Minimally Engaged Users with high specificity and sensitivity (AUROC= 0.94). Results suggest future research should develop and test interventions that promote activity, and hence cessation support, amongst specific user groups or at key time points. For example, early usage information could help identify Minimally Engaged Users for tests of targeted messaging designed to improve their integration into, or re-engagement with, the OCSN. Furthermore, although we observed strong growth over time on varied metrics including posts and comments, this change did not coincide with large gains in first-time user persistence. Researchers assessing intervention effects should therefore examine multiple measures when evaluating changes in network dynamics over time.

A global approach for using kinematic redundancy to minimize base reactions of manipulators

NASA Technical Reports Server (NTRS)

Chung, C. L.; Desa, S.

1989-01-01

An important consideration in the use of manipulators in microgravity environments is the minimization of the base reactions, i.e. the magnitude of the force and the moment exerted by the manipulator on its base as it performs its tasks. One approach which was proposed and implemented is to use the redundant degree of freedom in a kinematically redundant manipulator to plan manipulator trajectories to minimize base reactions. A global approach was developed for minimizing the magnitude of the base reactions for kinematically redundant manipulators which integrates the Partitioned Jacobian method of redundancy resolution, a 4-3-4 joint-trajectory representation and the minimization of a cost function which is the time-integral of the magnitude of the base reactions. The global approach was also compared with a local approach developed earlier for the case of point-to-point motion of a three degree-of-freedom planar manipulator with one redundant degree-of-freedom. The results show that the global approach is more effective in reducing and smoothing the base force while the local approach is superior in reducing the base moment.

Mini-Membrane Evaporator for Contingency Spacesuit Cooling

NASA Technical Reports Server (NTRS)

Makinen, Janice V.; Bue, Grant C.; Campbell, Colin; Petty, Brian; Craft, Jesse; Lynch, William; Wilkes, Robert; Vogel, Matthew

2015-01-01

The next-generation Advanced Extravehicular Mobility Unit (AEMU) Portable Life Support System (PLSS) is integrating a number of new technologies to improve reliability and functionality. One of these improvements is the development of the Auxiliary Cooling Loop (ACL) for contingency crewmember cooling. The ACL is a completely redundant, independent cooling system that consists of a small evaporative cooler--the Mini Membrane Evaporator (Mini-ME), independent pump, independent feedwater assembly and independent Liquid Cooling Garment (LCG). The Mini-ME utilizes the same hollow fiber technology featured in the full-sized AEMU PLSS cooling device, the Spacesuit Water Membrane Evaporator (SWME), but Mini-ME occupies only approximately 25% of the volume of SWME, thereby providing only the necessary crewmember cooling in a contingency situation. The ACL provides a number of benefits when compared with the current EMU PLSS contingency cooling technology, which relies upon a Secondary Oxygen Vessel; contingency crewmember cooling can be provided for a longer period of time, more contingency situations can be accounted for, no reliance on a Secondary Oxygen Vessel (SOV) for contingency cooling--thereby allowing a reduction in SOV size and pressure, and the ACL can be recharged-allowing the AEMU PLSS to be reused, even after a contingency event. The first iteration of Mini-ME was developed and tested in-house. Mini-ME is currently packaged in AEMU PLSS 2.0, where it is being tested in environments and situations that are representative of potential future Extravehicular Activities (EVA's). The second iteration of Mini-ME, known as Mini-ME2, is currently being developed to offer more heat rejection capability. The development of this contingency evaporative cooling system will contribute to a more robust and comprehensive AEMU PLSS.

Developing and Using Ada Parts in Real-Time Embedded Applications

DTIC Science & Technology

1990-04-27

ARCHTECTURAL DESIGN Guideline #3-a: Avoid duplication of data types packages. Guideline #3-b: Minimize variant proliferation. Concentrate on developing a...of SOFTWARE REUSE DEVELOPING and USING ADA PARTS in RTE APPUCATIONS ARCHTECTURAL DESIGN Table 5-10 illustrates the use of this more strongly data typed

Reconnaissance and Autonomy for Small Robots (RASR) team: MAGIC 2010 challenge

NASA Astrophysics Data System (ADS)

Lacaze, Alberto; Murphy, Karl; Del Giorno, Mark; Corley, Katrina

2012-06-01

The Reconnaissance and Autonomy for Small Robots (RASR) team developed a system for the coordination of groups of unmanned ground vehicles (UGVs) that can execute a variety of military relevant missions in dynamic urban environments. Historically, UGV operations have been primarily performed via tele-operation, requiring at least one dedicated operator per robot, and requiring substantial real-time bandwidth to accomplish those missions. Our team goal was to develop a system that can provide long-term value to the war-fighter, utilizing MAGIC-2010 as a stepping stone. To that end, we self-imposed a set of constraints that would force us to develop technology that could readily be used by the military in the near term: • Use a relevant (deployed) platform • Use low-cost, reliable sensors • Develop an expandable and modular control system with innovative software algorithms to minimize the computing footprint required • Minimize required communications bandwidth and handle communication losses • Minimize additional power requirements to maximize battery life and mission duration

Thermotolerance of human myometrium: implications for minimally invasive uterine therapies

NASA Astrophysics Data System (ADS)

Thomas, Aaron C.; Grisez, Brian T.; McMillan, Kathleen; Chill, Nicholas; Harclerode, Tyler P.; Radabaugh, Rebecca; Jones, Ryan M.; Coad, James E.

2013-02-01

Endometrial ablation has gained significant clinical acceptance over the last decade as a minimally invasive treatment for abnormal uterine bleeding. To improve upon current thermal injury modeling, it is important to better characterize the myometrium's thermotolerance. The extent of myometrial thermal injury was determined across a spectrum of thermal histories/doses (time-temperature combinations). Fresh extirpated human myometrium was obtained from 13 subjects who underwent a previous scheduled benign hysterectomy. Within two hours of hysterectomy, the unfixed myometrium was treated in a stabilized saline bath with temperatures ranging from 45-70 °C and time intervals from 30- 150 seconds. The time-temperature combinations were selected to simulate treatment times under 2.5 minutes. A total of six such thermal matrices, each comprised of 45 time-temperature combinations, were prepared for evaluation. The treated myometrium was cryosectioned for nitro blue tetrazolium (NBT) staining to assess for thermal respiratory enzyme inactivation. Image analysis was subsequently used to quantitatively assess the stained myometrium's capacity to metabolize the tetrazolium at each time-temperature combination. This colorimetric data was then used as marker of cellular viability and determine survival parameters with implications for developing minimally invasive uterine therapies.

Development of a minimization instrument for allocation of a hospital-level performance improvement intervention to reduce waiting times in Ontario emergency departments.

PubMed

Leaver, Chad Andrew; Guttmann, Astrid; Zwarenstein, Merrick; Rowe, Brian H; Anderson, Geoff; Stukel, Therese; Golden, Brian; Bell, Robert; Morra, Dante; Abrams, Howard; Schull, Michael J

2009-06-08

Rigorous evaluation of an intervention requires that its allocation be unbiased with respect to confounders; this is especially difficult in complex, system-wide healthcare interventions. We developed a short survey instrument to identify factors for a minimization algorithm for the allocation of a hospital-level intervention to reduce emergency department (ED) waiting times in Ontario, Canada. Potential confounders influencing the intervention's success were identified by literature review, and grouped by healthcare setting specific change stages. An international multi-disciplinary (clinical, administrative, decision maker, management) panel evaluated these factors in a two-stage modified-delphi and nominal group process based on four domains: change readiness, evidence base, face validity, and clarity of definition. An original set of 33 factors were identified from the literature. The panel reduced the list to 12 in the first round survey. In the second survey, experts scored each factor according to the four domains; summary scores and consensus discussion resulted in the final selection and measurement of four hospital-level factors to be used in the minimization algorithm: improved patient flow as a hospital's leadership priority; physicians' receptiveness to organizational change; efficiency of bed management; and physician incentives supporting the change goal. We developed a simple tool designed to gather data from senior hospital administrators on factors likely to affect the success of a hospital patient flow improvement intervention. A minimization algorithm will ensure balanced allocation of the intervention with respect to these factors in study hospitals.

Intercell scheduling: A negotiation approach using multi-agent coalitions

NASA Astrophysics Data System (ADS)

Tian, Yunna; Li, Dongni; Zheng, Dan; Jia, Yunde

2016-10-01

Intercell scheduling problems arise as a result of intercell transfers in cellular manufacturing systems. Flexible intercell routes are considered in this article, and a coalition-based scheduling (CBS) approach using distributed multi-agent negotiation is developed. Taking advantage of the extended vision of the coalition agents, the global optimization is improved and the communication cost is reduced. The objective of the addressed problem is to minimize mean tardiness. Computational results show that, compared with the widely used combinatorial rules, CBS provides better performance not only in minimizing the objective, i.e. mean tardiness, but also in minimizing auxiliary measures such as maximum completion time, mean flow time and the ratio of tardy parts. Moreover, CBS is better than the existing intercell scheduling approach for the same problem with respect to the solution quality and computational costs.

SSAT Presidential Address 2017 "Passion and the GI Surgeon".

PubMed

Soper, Nathaniel J

2018-01-01

Gastrointestinal (GI) surgery is a dynamic, exciting field that has dramatically evolved over the past three decades. According to a survey of leaders in GI surgery, the development of minimally invasive surgery has been the most significant advance during this period of time. The author traces his pursuit of minimally invasive surgery and its impact on his career satisfaction. Discovering one's passion within surgery and developing "flow" during operative procedures is important to help prevent burnout. Surgical educators must transmit this sense of passion to their trainees such that they can understand the true meaning of the surgical vocation.

Developing Higher Education Programs in Emergency Management: Ghana's Experience

ERIC Educational Resources Information Center

Yakubu, Mariama Bisongu

2013-01-01

Ghana is highly vulnerable and threatened by several hazards and has sought ways of minimizing impacts of hazards events over time including demonstrating an interest in developing an emergency management training and an higher education degree program. Yet, as of 2013, the country has not developed a disaster management training program or a…

The timing of flowering in Douglas-fir is determined by cool-season temperatures and genetic variation

Treesearch

Janet S. Prevey; Constance A. Harrington; J. Bradley St. Clair

2018-01-01

Trees have evolved to time flowering to maximize outcrossing, minimize exposure to damaging frosts, and synchronize development with soil moisture and nutrient availability. Understanding the environmental cues that influence the timing of reproductive budburst will be important for predicting how flowering phenology of trees will change with a changing climate, and...

Emergency material allocation with time-varying supply-demand based on dynamic optimization method for river chemical spills.

PubMed

Liu, Jie; Guo, Liang; Jiang, Jiping; Jiang, Dexun; Wang, Peng

2018-04-13

Aiming to minimize the damage caused by river chemical spills, efficient emergency material allocation is critical for an actual emergency rescue decision-making in a quick response. In this study, an emergency material allocation framework based on time-varying supply-demand constraint is developed to allocate emergency material, minimize the emergency response time, and satisfy the dynamic emergency material requirements in post-accident phases dealing with river chemical spills. In this study, the theoretically critical emergency response time is firstly obtained for the emergency material allocation system to select a series of appropriate emergency material warehouses as potential supportive centers. Then, an enumeration method is applied to identify the practically critical emergency response time, the optimum emergency material allocation and replenishment scheme. Finally, the developed framework is applied to a computational experiment based on south-to-north water transfer project in China. The results illustrate that the proposed methodology is a simple and flexible tool for appropriately allocating emergency material to satisfy time-dynamic demands during emergency decision-making. Therefore, the decision-makers can identify an appropriate emergency material allocation scheme in a balance between time-effective and cost-effective objectives under the different emergency pollution conditions.

The Spectrum of Reversible Minimizers

NASA Astrophysics Data System (ADS)

Ureña, Antonio J.

2018-05-01

Poincaré and, later on, Carathéodory, showed that the Floquet multipliers of 1-dimensional periodic curves minimizing the Lagrangian action are real and positive. Even though Carathéodory himself observed that this result loses its validity in the general higherdimensional case, we shall show that it remains true for systems which are reversible in time. In this way, we also generalize a previous result by Offin on the hyperbolicity of nondegenerate symmetric minimizers. Our arguments rely on the higher-dimensional generalizations of the Sturm theory which were developed during the second half of the twentieth century by several authors, including Hartman, Morse or Arnol'd.

Minimalism in Art, Medical Science and Neurosurgery.

PubMed

Okten, Ali Ihsan

2018-01-01

The word "minimalism" is a word derived from French the word "minimum". Whereas the lexical meaning of minimum is "the least or the smallest quantity necessary for something", its expression in mathematics can be described as "the lowest step a variable number can descend, least, minimal". Minimalism, which advocates an extreme simplicity of the artistic form, is a current in modern art and music whose origins go to 1960s and which features simplicity and objectivity. Although art, science and philosophy are different disciplines, they support each other from time to time, sometimes they intertwine and sometimes they copy each other. A periodic schools or teaching in one of them can take the others into itself, so, they proceed on their ways empowering each other. It is also true for the minimalism in art and the minimal invasive surgical approaches in science. Concepts like doing with less, avoiding unnecessary materials and reducing the number of the elements in order to increase the effect in the expression which are the main elements of the minimalism in art found their equivalents in medicine and neurosurgery. Their equivalents in medicine or neurosurgery have been to protect the physical integrity of the patient with less iatrogenic injury, minimum damage and the same therapeutic effect in the most effective way and to enable the patient to regain his health in the shortest span of time. As an anticipation, we can consider that the minimal approaches started by Richard Wollheim and Barbara Rose in art and Lars Leksell, Gazi Yaşargil and other neurosurgeons in neurosurgery in the 1960s are the present day equivalents of the minimalist approaches perhaps unconsciously started by Kazimir Malevich in art and Victor Darwin L"Espinasse in neurosurgery in the early 1900s. We can also consider that they have developed interacting with each other, not by chance.

A dispersion minimizing scheme for the 3-D Helmholtz equation based on ray theory

NASA Astrophysics Data System (ADS)

Stolk, Christiaan C.

2016-06-01

We develop a new dispersion minimizing compact finite difference scheme for the Helmholtz equation in 2 and 3 dimensions. The scheme is based on a newly developed ray theory for difference equations. A discrete Helmholtz operator and a discrete operator to be applied to the source and the wavefields are constructed. Their coefficients are piecewise polynomial functions of hk, chosen such that phase and amplitude errors are minimal. The phase errors of the scheme are very small, approximately as small as those of the 2-D quasi-stabilized FEM method and substantially smaller than those of alternatives in 3-D, assuming the same number of gridpoints per wavelength is used. In numerical experiments, accurate solutions are obtained in constant and smoothly varying media using meshes with only five to six points per wavelength and wave propagation over hundreds of wavelengths. When used as a coarse level discretization in a multigrid method the scheme can even be used with down to three points per wavelength. Tests on 3-D examples with up to 108 degrees of freedom show that with a recently developed hybrid solver, the use of coarser meshes can lead to corresponding savings in computation time, resulting in good simulation times compared to the literature.

Wideband Agile Digital Microwave Radiometer

NASA Technical Reports Server (NTRS)

Gaier, Todd C.; Brown, Shannon T.; Ruf, Christopher; Gross, Steven

2012-01-01

The objectives of this work were to take the initial steps needed to develop a field programmable gate array (FPGA)- based wideband digital radiometer backend (>500 MHz bandwidth) that will enable passive microwave observations with minimal performance degradation in a radiofrequency-interference (RFI)-rich environment. As manmade RF emissions increase over time and fill more of the microwave spectrum, microwave radiometer science applications will be increasingly impacted in a negative way, and the current generation of spaceborne microwave radiometers that use broadband analog back ends will become severely compromised or unusable over an increasing fraction of time on orbit. There is a need to develop a digital radiometer back end that, for each observation period, uses digital signal processing (DSP) algorithms to identify the maximum amount of RFI-free spectrum across the radiometer band to preserve bandwidth to minimize radiometer noise (which is inversely related to the bandwidth). Ultimately, the objective is to incorporate all processing necessary in the back end to take contaminated input spectra and produce a single output value free of manmade signals to minimize data rates for spaceborne radiometer missions. But, to meet these objectives, several intermediate processing algorithms had to be developed, and their performance characterized relative to typical brightness temperature accuracy re quirements for current and future microwave radiometer missions, including those for measuring salinity, soil moisture, and snow pack.

Time Management in the Operating Room: An Analysis of the Dedicated Minimally Invasive Surgery Suite

PubMed Central

Hsiao, Kenneth C.; Machaidze, Zurab

2004-01-01

Background: Dedicated minimally invasive surgery suites are available that contain specialized equipment to facilitate endoscopic surgery. Laparoscopy performed in a general operating room is hampered by the multitude of additional equipment that must be transported into the room. The objective of this study was to compare the preparation times between procedures performed in traditional operating rooms versus dedicated minimally invasive surgery suites to see whether operating room efficiency is improved in the specialized room. Methods: The records of 50 patients who underwent laparoscopic procedures between September 2000 and April 2002 were retrospectively reviewed. Twenty-three patients underwent surgery in a general operating room and 18 patients in an minimally invasive surgery suite. Nine patients were excluded because of cystoscopic procedures undergone prior to laparoscopy. Various time points were recorded from which various time intervals were derived, such as preanesthesia time, anesthesia induction time, and total preparation time. A 2-tailed, unpaired Student t test was used for statistical analysis. Results: The mean preanesthesia time was significantly faster in the minimally invasive surgery suite (12.2 minutes) compared with that in the traditional operating room (17.8 minutes) (P=0.013). Mean anesthesia induction time in the minimally invasive surgery suite (47.5 minutes) was similar to time in the traditional operating room (45.7 minutes) (P=0.734). The average total preparation time for the minimally invasive surgery suite (59.6 minutes) was not significantly faster than that in the general operating room (63.5 minutes) (P=0.481). Conclusion: The amount of time that elapses between the patient entering the room and anesthesia induction is statically shorter in a dedicated minimally invasive surgery suite. Laparoscopic surgery is performed more efficiently in a dedicated minimally invasive surgery suite versus a traditional operating room. PMID:15554269

Land transportation model for supply chain manufacturing industries

NASA Astrophysics Data System (ADS)

Kurniawan, Fajar

2017-12-01

Supply chain is a system that integrates production, inventory, distribution and information processes for increasing productivity and minimize costs. Transportation is an important part of the supply chain system, especially for supporting the material distribution process, work in process products and final products. In fact, Jakarta as the distribution center of manufacturing industries for the industrial area. Transportation system has a large influences on the implementation of supply chain process efficiency. The main problem faced in Jakarta is traffic jam that will affect on the time of distribution. Based on the system dynamic model, there are several scenarios that can provide solutions to minimize timing of distribution that will effect on the cost such as the construction of ports approaching industrial areas other than Tanjung Priok, widening road facilities, development of railways system, and the development of distribution center.

Multi objective optimization model for minimizing production cost and environmental impact in CNC turning process

NASA Astrophysics Data System (ADS)

Widhiarso, Wahyu; Rosyidi, Cucuk Nur

2018-02-01

Minimizing production cost in a manufacturing company will increase the profit of the company. The cutting parameters will affect total processing time which then will affect the production cost of machining process. Besides affecting the production cost and processing time, the cutting parameters will also affect the environment. An optimization model is needed to determine the optimum cutting parameters. In this paper, we develop an optimization model to minimize the production cost and the environmental impact in CNC turning process. The model is used a multi objective optimization. Cutting speed and feed rate are served as the decision variables. Constraints considered are cutting speed, feed rate, cutting force, output power, and surface roughness. The environmental impact is converted from the environmental burden by using eco-indicator 99. Numerical example is given to show the implementation of the model and solved using OptQuest of Oracle Crystal Ball software. The results of optimization indicate that the model can be used to optimize the cutting parameters to minimize the production cost and the environmental impact.

Mini-Membrane Evaporator for Contingency Spacesuit Cooling

NASA Technical Reports Server (NTRS)

Makinen, Janice V.; Bue, Grant C.; Campbell, Colin; Craft, Jesse; Lynch, William; Wilkes, Robert; Vogel, Matthew

2014-01-01

The next-generation Advanced Extravehicular Mobility Unit (AEMU) Portable Life Support System (PLSS) is integrating a number of new technologies to improve reliability and functionality. One of these improvements is the development of the Auxiliary Cooling Loop (ACL) for contingency crewmember cooling. The ACL is a completely redundant, independent cooling system that consists of a small evaporative cooler--the Mini Membrane Evaporator (Mini-ME), independent pump, independent feedwater assembly and independent Liquid Cooling Garment (LCG). The Mini-ME utilizes the same hollow fiber technology featured in the full-sized AEMU PLSS cooling device, the Spacesuit Water Membrane Evaporator (SWME), but Mini-ME occupies only 25% of the volume of SWME, thereby providing only the necessary crewmember cooling in a contingency situation. The ACL provides a number of benefits when compared with the current EMU PLSS contingency cooling technology, which relies upon a Secondary Oxygen Vessel; contingency crewmember cooling can be provided for a longer period of time, more contingency situations can be accounted for, no reliance on a Secondary Oxygen Vessel (SOV) for contingency cooling--thereby allowing a reduction in SOV size and pressure, and the ACL can be recharged-allowing the AEMU PLSS to be reused, even after a contingency event. The first iteration of Mini-ME was developed and tested in-house. Mini-ME is currently packaged in AEMU PLSS 2.0, where it is being tested in environments and situations that are representative of potential future Extravehicular Activities (EVA's). The second iteration of Mini-ME, known as Mini- ME2, is currently being developed to offer more heat rejection capability. The development of this contingency evaporative cooling system will contribute to a more robust and comprehensive AEMU PLSS.

Use of minimally invasive spine surgical instruments for the treatment of bone tumors.

PubMed

Reeves, Russell A; DeWolf, Matthew C; Shaughnessy, Peter J; Ames, James B; Henderson, Eric R

2017-11-01

Orthopedic oncologists often encounter patients with minor bony lesions that are difficult to access surgically and therefore require large exposures out of proportion to the severity of disease that confer significant patient morbidity. Minimally invasive surgical techniques offer the advantage of smaller incisions, shorter operative times, decreased tissue damage, and decreased costs. A variety of surgical procedures have emerged using minimally invasive technologies, particularly in the field of spine surgery. Areas covered: In this article, we describe the Minimal Exposure Tubular Retractor (METRx TM ) System which is a minimally invasive surgical device that utilizes a series of dilators to permit access to a surgical site of interest. This system was developed for use in treatment of disc herniation, spinal stenosis, posterior lumbar interbody fusion, transforaminal lumbar interbody fusion and spinal cord stimulation implantation. We also describe novel uses of this system for minimally invasive biopsy and treatment of benign and metastatic bone lesions at our institution. Expert commentary: Minimally invasive surgical techniques will continue to expand into the field of orthopedic oncology. With a greater number of studies proving the safety and effectiveness of this technique, the demand for minimally invasive treatments will grow.

Development of a real-time chemical injection system for air-assisted variable-rate sprayers

USDA-ARS?s Scientific Manuscript database

A chemical injection system is an effective method to minimize chemical waste and reduce the environmental pollution in pesticide spray applications. A microprocessor controlled injection system implementing a ceramic piston metering pump was developed to accurately dispense chemicals to be mixed wi...

The SCUBA Data Reduction Pipeline: ORAC-DR at the JCMT

NASA Astrophysics Data System (ADS)

Jenness, Tim; Economou, Frossie

The ORAC data reduction pipeline, developed for UKIRT, has been designed to be a completely general approach to writing data reduction pipelines. This generality has enabled the JCMT to adapt the system for use with SCUBA with minimal development time using the existing SCUBA data reduction algorithms (Surf).

Mechanics of Disease Control in Production Operations

USDA-ARS?s Scientific Manuscript database

Disease problems develop when the surfaces of susceptible plant tissue (part 1) are colonized by a virulent pathogen (part 2) at the time when conditions are conducive for infection and disease development (part 3). Negatively effect one or more of the three parts, then disease can be minimized or e...

Posting Behaviour Patterns in an Online Smoking Cessation Social Network: Implications for Intervention Design and Development

PubMed Central

Healey, Benjamin; Hoek, Janet; Edwards, Richard

2014-01-01

Objectives Online Cessation Support Networks (OCSNs) are associated with increased quit success rates, but few studies have examined their use over time. We identified usage patterns in New Zealand's largest OCSN over two years and explored implications for OCSN intervention design and evaluation. Methods We analysed metadata relating to 133,096 OCSN interactions during 2011 and 2012. Metrics covered aggregate network activity, user posting activity and longevity, and between-user commenting. Binary logistic regression models were estimated to investigate the feasibility of predicting low user engagement using early interaction data. Results Repeating periodic peaks and troughs in aggregate activity related not only to seasonality (e.g., New Year), but also to day of the week. Out of 2,062 unique users, 69 Highly Engaged Users (180+ interactions each) contributed 69% of all OCSN interactions in 2012 compared to 1.3% contributed by 864 Minimally Engaged Users (< = 2 items each). The proportion of Highly Engaged Users increased with network growth between 2011 and 2012 (with marginal significance), but the proportion of Minimally Engaged Users did not decline substantively. First week interaction data enabled identification of Minimally Engaged Users with high specificity and sensitivity (AUROC  = 0.94). Implications Results suggest future research should develop and test interventions that promote activity, and hence cessation support, amongst specific user groups or at key time points. For example, early usage information could help identify Minimally Engaged Users for tests of targeted messaging designed to improve their integration into, or re-engagement with, the OCSN. Furthermore, although we observed strong growth over time on varied metrics including posts and comments, this change did not coincide with large gains in first-time user persistence. Researchers assessing intervention effects should therefore examine multiple measures when evaluating changes in network dynamics over time. PMID:25192174

Reference Network Real-Time Services Control Techniques

NASA Astrophysics Data System (ADS)

Nykiel, Grzegorz; Szolucha, Marcin

2013-04-01

Differential corrections and services for real-time kinematic method (RTK) in many cases are used to support survey being base for administration decision. For that reason, services which allow to perform GNSS measurements should be constantly monitored to minimize the risk of any errors or unexpected gap in observation. System providing such control is the subject of the work carried out under a grant NR09-0010-10/2010 conducted by the Military University of Technology. This study was made to develop the concept of monitoring real-time services of Polish reference network ASG-EUPOS and the implementation of software providing users information on system accuracy. The main objectives of all concepts were: maximum use of existing infrastructure while minimizing the cost of installation of new elements, providing users calculation results via the ASG-EUPOS website. In the same time concept assume openness of the module that allow the successive development of applications and integration with existing solutions. This paper present several solutions and algorithms which have been implemented and tested. It also consist some examples of data visualization methods.

Real-Time Navigation System Implementation Within the Scope of 3d Geographic Information Systems for Multi Storey CAR Park

NASA Astrophysics Data System (ADS)

Yenigun, B.; Karas, I. R.; Demiral, E.

2016-10-01

Today, a large increase in the number of vehicles in traffic with population growth and economic development are observed. This increase brings with it many problems. One of these problems is the parking problem as a result of the need to park the vehicle. Impractical and inadequate parking areas have a negative impact on drivers. To minimize these drawbacks, car parking is intended to develop a system to come to the aid of users. This system is planned to be developed which can be applied to indoor and multi-storey parking structure. Considered in this study, in the garage, drivers are intended to be directed as soon as possible in place of the convenient parking. However, the amount of fuel spent looking for parking tool that are caused by air and noise pollution, and to search for a parking lot when looking for a place to park the lost time, the resulting stress is minimized, it is expected that.

Development and experimental assessment of a numerical modelling code to aid the design of profile extrusion cooling tools

NASA Astrophysics Data System (ADS)

Carneiro, O. S.; Rajkumar, A.; Fernandes, C.; Ferrás, L. L.; Habla, F.; Nóbrega, J. M.

2017-10-01

On the extrusion of thermoplastic profiles, upon the forming stage that takes place in the extrusion die, the profile must be cooled in a metallic calibrator. This stage must be done at a high rate, to assure increased productivity, but avoiding the development of high temperature gradients, in order to minimize the level of induced thermal residual stresses. In this work, we present a new coupled numerical solver, developed in the framework of the OpenFOAM® computational library, that computes the temperature distribution in both domains simultaneously (metallic calibrator and plastic profile), whose implementation aimed the minimization of the computational time. The new solver was experimentally assessed with an industrial case study.

Economics of gynecologic morcellation.

PubMed

Bortoletto, Pietro; Friedman, Jaclyn; Milad, Magdy P

2018-02-01

As the Food and Drug Administration raised concern over the power morcellator in 2014, the field has seen significant change, with patients and physicians questioning which procedure is safest and most cost-effective. The economic impact of these decisions is poorly understood. Multiple new technologies have been developed to allow surgeons to continue to afford patients the many benefits of minimally invasive surgery while minimizing the risks of power morcellation. At the same time, researchers have focused on the true benefits of the power morcellator from a safety and cost perspective, and consistently found that with careful patient selection, by preventing laparotomies, it can be a cost-effective tool. Changes since 2014 have resulted in new techniques and technologies to allow these minimally invasive procedures to continue to be offered in a safe manner. With this rapid change, physicians are altering their practice and patients are attempting to educate themselves to decide what is best for them. This evolution has allowed us to refocus on the cost implications of new developments, allowing stakeholders the opportunity to maximize patient safety and surgical outcomes while minimizing cost.

Modeling of electrical and mesoscopic circuits at quantum nanoscale from heat momentum operator

NASA Astrophysics Data System (ADS)

El-Nabulsi, Rami Ahmad

2018-04-01

We develop a new method to study electrical circuits at quantum nanoscale by introducing a heat momentum operator which reproduces quantum effects similar to those obtained in Suykens's nonlocal-in-time kinetic energy approach for the case of reversible motion. The series expansion of the heat momentum operator is similar to the momentum operator obtained in the framework of minimal length phenomenologies characterized by the deformation of Heisenberg algebra. The quantization of both LC and mesoscopic circuits revealed a number of motivating features like the emergence of a generalized uncertainty relation and a minimal charge similar to those obtained in the framework of minimal length theories. Additional features were obtained and discussed accordingly.

Optimization of motion control laws for tether crawler or elevator systems

NASA Technical Reports Server (NTRS)

Swenson, Frank R.; Von Tiesenhausen, Georg

1988-01-01

Based on the proposal of a motion control law by Lorenzini (1987), a method is developed for optimizing motion control laws for tether crawler or elevator systems in terms of the performance measures of travel time, the smoothness of acceleration and deceleration, and the maximum values of velocity and acceleration. The Lorenzini motion control law, based on powers of the hyperbolic tangent function, is modified by the addition of a constant-velocity section, and this modified function is then optimized by parameter selections to minimize the peak acceleration value for a selected travel time or to minimize travel time for the selected peak values of velocity and acceleration. It is shown that the addition of a constant-velocity segment permits further optimization of the motion control law performance.

Reliability enhancement of Navier-Stokes codes through convergence enhancement

NASA Technical Reports Server (NTRS)

Choi, K.-Y.; Dulikravich, G. S.

1993-01-01

Reduction of total computing time required by an iterative algorithm for solving Navier-Stokes equations is an important aspect of making the existing and future analysis codes more cost effective. Several attempts have been made to accelerate the convergence of an explicit Runge-Kutta time-stepping algorithm. These acceleration methods are based on local time stepping, implicit residual smoothing, enthalpy damping, and multigrid techniques. Also, an extrapolation procedure based on the power method and the Minimal Residual Method (MRM) were applied to the Jameson's multigrid algorithm. The MRM uses same values of optimal weights for the corrections to every equation in a system and has not been shown to accelerate the scheme without multigriding. Our Distributed Minimal Residual (DMR) method based on our General Nonlinear Minimal Residual (GNLMR) method allows each component of the solution vector in a system of equations to have its own convergence speed. The DMR method was found capable of reducing the computation time by 10-75 percent depending on the test case and grid used. Recently, we have developed and tested a new method termed Sensitivity Based DMR or SBMR method that is easier to implement in different codes and is even more robust and computationally efficient than our DMR method.

Reliability enhancement of Navier-Stokes codes through convergence enhancement

NASA Astrophysics Data System (ADS)

Choi, K.-Y.; Dulikravich, G. S.

1993-11-01

Reduction of total computing time required by an iterative algorithm for solving Navier-Stokes equations is an important aspect of making the existing and future analysis codes more cost effective. Several attempts have been made to accelerate the convergence of an explicit Runge-Kutta time-stepping algorithm. These acceleration methods are based on local time stepping, implicit residual smoothing, enthalpy damping, and multigrid techniques. Also, an extrapolation procedure based on the power method and the Minimal Residual Method (MRM) were applied to the Jameson's multigrid algorithm. The MRM uses same values of optimal weights for the corrections to every equation in a system and has not been shown to accelerate the scheme without multigriding. Our Distributed Minimal Residual (DMR) method based on our General Nonlinear Minimal Residual (GNLMR) method allows each component of the solution vector in a system of equations to have its own convergence speed. The DMR method was found capable of reducing the computation time by 10-75 percent depending on the test case and grid used. Recently, we have developed and tested a new method termed Sensitivity Based DMR or SBMR method that is easier to implement in different codes and is even more robust and computationally efficient than our DMR method.

Minimization principles for the coupled problem of Darcy-Biot-type fluid transport in porous media linked to phase field modeling of fracture

NASA Astrophysics Data System (ADS)

Miehe, Christian; Mauthe, Steffen; Teichtmeister, Stephan

2015-09-01

This work develops new minimization and saddle point principles for the coupled problem of Darcy-Biot-type fluid transport in porous media at fracture. It shows that the quasi-static problem of elastically deforming, fluid-saturated porous media is related to a minimization principle for the evolution problem. This two-field principle determines the rate of deformation and the fluid mass flux vector. It provides a canonically compact model structure, where the stress equilibrium and the inverse Darcy's law appear as the Euler equations of a variational statement. A Legendre transformation of the dissipation potential relates the minimization principle to a characteristic three field saddle point principle, whose Euler equations determine the evolutions of deformation and fluid content as well as Darcy's law. A further geometric assumption results in modified variational principles for a simplified theory, where the fluid content is linked to the volumetric deformation. The existence of these variational principles underlines inherent symmetries of Darcy-Biot theories of porous media. This can be exploited in the numerical implementation by the construction of time- and space-discrete variational principles, which fully determine the update problems of typical time stepping schemes. Here, the proposed minimization principle for the coupled problem is advantageous with regard to a new unconstrained stable finite element design, while space discretizations of the saddle point principles are constrained by the LBB condition. The variational principles developed provide the most fundamental approach to the discretization of nonlinear fluid-structure interactions, showing symmetric systems in algebraic update procedures. They also provide an excellent starting point for extensions towards more complex problems. This is demonstrated by developing a minimization principle for a phase field description of fracture in fluid-saturated porous media. It is designed for an incorporation of alternative crack driving forces, such as a convenient criterion in terms of the effective stress. The proposed setting provides a modeling framework for the analysis of complex problems such as hydraulic fracture. This is demonstrated by a spectrum of model simulations.

Management of pilonidal disease.

PubMed

Kallis, Michelle P; Maloney, Caroline; Lipskar, Aaron M

2018-06-01

Pilonidal disease, and the treatment associated with it, can cause significant morbidity and substantial burden to patients' quality of life. Despite the plethora of surgical techniques that have been developed to treat pilonidal disease, discrepancies in technique, recurrence rates, complications, time to return to work/school and patients' aesthetic satisfaction between treatment options have led to controversy over the best approach to this common acquired disease of young adults. The management of pilonidal disease must strike a balance between recurrence and surgical morbidity. The commonly performed wide excision without closure has prolonged recovery, while flap closures speed recovery time and improve aesthetics at the expense of increased wound complications. Less invasive surgical techniques have recently evolved and are straightforward, with minimal morbidity and satisfactory results. As with any surgical intervention, the ideal treatment for pilonidal disease would be simple and cost-effective, cause minimal pain, have a limited hospital stay, low recurrence rate and require minimal time off from school or work. Less invasive procedures for pilonidal disease may be favourable as an initial approach for these patients reserving complex surgical treatment for refractory disease.

The use of time-of-flight camera for navigating robots in computer-aided surgery: monitoring the soft tissue envelope of minimally invasive hip approach in a cadaver study.

PubMed

Putzer, David; Klug, Sebastian; Moctezuma, Jose Luis; Nogler, Michael

2014-12-01

Time-of-flight (TOF) cameras can guide surgical robots or provide soft tissue information for augmented reality in the medical field. In this study, a method to automatically track the soft tissue envelope of a minimally invasive hip approach in a cadaver study is described. An algorithm for the TOF camera was developed and 30 measurements on 8 surgical situs (direct anterior approach) were carried out. The results were compared to a manual measurement of the soft tissue envelope. The TOF camera showed an overall recognition rate of the soft tissue envelope of 75%. On comparing the results from the algorithm with the manual measurements, a significant difference was found (P > .005). In this preliminary study, we have presented a method for automatically recognizing the soft tissue envelope of the surgical field in a real-time application. Further improvements could result in a robotic navigation device for minimally invasive hip surgery. © The Author(s) 2014.

A Retrospective Comparison of Conventional versus Transverse Mini-Incision Technique for Carpal Tunnel Release

PubMed Central

Gülşen, İsmail; Ak, Hakan; Evcılı, Gökhan; Balbaloglu, Özlem; Sösüncü, Enver

2013-01-01

Background. In this retrospective study, we aimed to compare the results of two surgical techniques, conventional and transverse mini-incision. Materials and Methods. 95 patients were operated between 2011 and 2012 in Bitlis State Hospital. 50 patients were operated with conventional technique and 45 of them were operated with minimal transverse incision. Postoperative complications, incision site problems, and the time of starting to use their hands in daily activities were noted. Results. 95 patients were included in the study. The mean age was 48. 87 of them were female and 8 were male. There was no problem of incision site in both of the two surgical techniques. Only in one patient, anesthesia developed in minimal incision technique. The time of starting to use their hands in daily activities was 22,2 days and 17 days in conventional and minimal incision technique, respectively. Conclusion. Two surgical techniques did not show superiority to each other in terms of postoperative complications and incision site problems except the time of starting to use their hands in daily activities. PMID:24396607

Standoff laser-based spectroscopy for explosives detection

NASA Astrophysics Data System (ADS)

Gaft, M.; Nagli, L.

2007-10-01

Real time detection and identification of explosives at a standoff distance is a major issue in efforts to develop defense against so-called Improvised Explosive Devices (IED). It is recognized that the only technique, which is potentially capable to standoff detection of minimal amounts of explosives is laser-based spectroscopy. LDS activity is based on a combination of laser-based spectroscopic methods with orthogonal capabilities. Our technique belongs to trace detection, namely to its micro-particles variety. It is based on commonly held belief that surface contamination was very difficult to avoid and could be exploited for standoff detection. We has applied optical techniques including gated Raman and time-resolved luminescence spectroscopy for detection of main explosive materials, both factory and homemade. We developed and tested a Raman system for the field remote detection and identification of minimal amounts of explosives on relevant surfaces at a distance of up to 30 meters.

Cross-bispectrum computation and variance estimation

NASA Technical Reports Server (NTRS)

Lii, K. S.; Helland, K. N.

1981-01-01

A method for the estimation of cross-bispectra of discrete real time series is developed. The asymptotic variance properties of the bispectrum are reviewed, and a method for the direct estimation of bispectral variance is given. The symmetry properties are described which minimize the computations necessary to obtain a complete estimate of the cross-bispectrum in the right-half-plane. A procedure is given for computing the cross-bispectrum by subdividing the domain into rectangular averaging regions which help reduce the variance of the estimates and allow easy application of the symmetry relationships to minimize the computational effort. As an example of the procedure, the cross-bispectrum of a numerically generated, exponentially distributed time series is computed and compared with theory.

Real-time minimal-bit-error probability decoding of convolutional codes

NASA Technical Reports Server (NTRS)

Lee, L.-N.

1974-01-01

A recursive procedure is derived for decoding of rate R = 1/n binary convolutional codes which minimizes the probability of the individual decoding decisions for each information bit, subject to the constraint that the decoding delay be limited to Delta branches. This new decoding algorithm is similar to, but somewhat more complex than, the Viterbi decoding algorithm. A real-time, i.e., fixed decoding delay, version of the Viterbi algorithm is also developed and used for comparison to the new algorithm on simulated channels. It is shown that the new algorithm offers advantages over Viterbi decoding in soft-decision applications, such as in the inner coding system for concatenated coding.

Real-time minimal bit error probability decoding of convolutional codes

NASA Technical Reports Server (NTRS)

Lee, L. N.

1973-01-01

A recursive procedure is derived for decoding of rate R=1/n binary convolutional codes which minimizes the probability of the individual decoding decisions for each information bit subject to the constraint that the decoding delay be limited to Delta branches. This new decoding algorithm is similar to, but somewhat more complex than, the Viterbi decoding algorithm. A real-time, i.e. fixed decoding delay, version of the Viterbi algorithm is also developed and used for comparison to the new algorithm on simulated channels. It is shown that the new algorithm offers advantages over Viterbi decoding in soft-decision applications such as in the inner coding system for concatenated coding.

Minimizing patient waiting time in emergency department of public hospital using simulation optimization approach

NASA Astrophysics Data System (ADS)

Ibrahim, Ireen Munira; Liong, Choong-Yeun; Bakar, Sakhinah Abu; Ahmad, Norazura; Najmuddin, Ahmad Farid

2017-04-01

Emergency department (ED) is the main unit of a hospital that provides emergency treatment. Operating 24 hours a day with limited number of resources invites more problems to the current chaotic situation in some hospitals in Malaysia. Delays in getting treatments that caused patients to wait for a long period of time are among the frequent complaints against government hospitals. Therefore, the ED management needs a model that can be used to examine and understand resource capacity which can assist the hospital managers to reduce patients waiting time. Simulation model was developed based on 24 hours data collection. The model developed using Arena simulation replicates the actual ED's operations of a public hospital in Selangor, Malaysia. The OptQuest optimization in Arena is used to find the possible combinations of a number of resources that can minimize patients waiting time while increasing the number of patients served. The simulation model was modified for improvement based on results from OptQuest. The improvement model significantly improves ED's efficiency with an average of 32% reduction in average patients waiting times and 25% increase in the total number of patients served.

Incorporating Auditory Models in Speech/Audio Applications

NASA Astrophysics Data System (ADS)

Krishnamoorthi, Harish

2011-12-01

Following the success in incorporating perceptual models in audio coding algorithms, their application in other speech/audio processing systems is expanding. In general, all perceptual speech/audio processing algorithms involve minimization of an objective function that directly/indirectly incorporates properties of human perception. This dissertation primarily investigates the problems associated with directly embedding an auditory model in the objective function formulation and proposes possible solutions to overcome high complexity issues for use in real-time speech/audio algorithms. Specific problems addressed in this dissertation include: 1) the development of approximate but computationally efficient auditory model implementations that are consistent with the principles of psychoacoustics, 2) the development of a mapping scheme that allows synthesizing a time/frequency domain representation from its equivalent auditory model output. The first problem is aimed at addressing the high computational complexity involved in solving perceptual objective functions that require repeated application of auditory model for evaluation of different candidate solutions. In this dissertation, a frequency pruning and a detector pruning algorithm is developed that efficiently implements the various auditory model stages. The performance of the pruned model is compared to that of the original auditory model for different types of test signals in the SQAM database. Experimental results indicate only a 4-7% relative error in loudness while attaining up to 80-90 % reduction in computational complexity. Similarly, a hybrid algorithm is developed specifically for use with sinusoidal signals and employs the proposed auditory pattern combining technique together with a look-up table to store representative auditory patterns. The second problem obtains an estimate of the auditory representation that minimizes a perceptual objective function and transforms the auditory pattern back to its equivalent time/frequency representation. This avoids the repeated application of auditory model stages to test different candidate time/frequency vectors in minimizing perceptual objective functions. In this dissertation, a constrained mapping scheme is developed by linearizing certain auditory model stages that ensures obtaining a time/frequency mapping corresponding to the estimated auditory representation. This paradigm was successfully incorporated in a perceptual speech enhancement algorithm and a sinusoidal component selection task.

A Prospective Randomized Study on Operative Treatment for Simple Distal Tibial Fractures-Minimally Invasive Plate Osteosynthesis Versus Minimal Open Reduction and Internal Fixation.

PubMed

Kim, Ji Wan; Kim, Hyun Uk; Oh, Chang-Wug; Kim, Joon-Woo; Park, Ki Chul

2018-01-01

To compare the radiologic and clinical results of minimally invasive plate osteosynthesis (MIPO) and minimal open reduction and internal fixation (ORIF) for simple distal tibial fractures. Randomized prospective study. Three level 1 trauma centers. Fifty-eight patients with simple and distal tibial fractures were randomized into a MIPO group (treatment with MIPO; n = 29) or a minimal group (treatment with minimal ORIF; n = 29). These numbers were designed to define the rate of soft tissue complication; therefore, validation of superiority in union time or determination of differences in rates of delayed union was limited in this study. Simple distal tibial fractures treated with MIPO or minimal ORIF. The clinical outcome measurements included operative time, radiation exposure time, and soft tissue complications. To evaluate a patient's function, the American Orthopedic Foot and Ankle Society ankle score (AOFAS) was used. Radiologic measurements included fracture alignment, delayed union, and union time. All patients acquired bone union without any secondary intervention. The mean union time was 17.4 weeks and 16.3 weeks in the MIPO and minimal groups, respectively. There was 1 case of delayed union and 1 case of superficial infection in each group. The radiation exposure time was shorter in the minimal group than in the MIPO group. Coronal angulation showed a difference between both groups. The American Orthopedic Foot and Ankle Society ankle scores were 86.0 and 86.7 in the MIPO and minimal groups, respectively. Minimal ORIF resulted in similar outcomes, with no increased rate of soft tissue problems compared to MIPO. Both MIPO and minimal ORIF have high union rates and good functional outcomes for simple distal tibial fractures. Minimal ORIF did not result in increased rates of infection and wound dehiscence. Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Identifying Minimal Changes in Nonerosive Reflux Disease: Is the Pay Worth the Labor?

PubMed

Gabbard, Scott L; Fass, Ronnie; Maradey-Romero, Carla; Gingold Belfer, Rachel; Dickman, Ram

2016-01-01

Gastroesophageal reflux disease has a variable presentation on upper endoscopy. Gastroesophageal reflux disease can be divided into 3 endoscopic categories: Barrett's esophagus, erosive esophagitis, and normal mucosa/nonerosive reflux disease (NERD). Each of these phenotypes behave in a distinct manner, in regards to symptom response to treatment, and risk of development of complications such as esophageal adenocarcinoma. Recently, it has been proposed to further differentiate NERD into 2 categories: those with and those without "minimal changes." These minimal changes include endoscopic abnormalities, such as villous mucosal surface, mucosal islands, microerosions, and increased vascularity at the squamocolumnar junction. Although some studies have shown that patients with minimal changes may have higher rates of esophageal acid exposure compared with those without minimal changes, it is currently unclear if these patients behave differently than those currently categorized as having NERD. The clinical utility of identifying these lesions should be weighed against the cost of the requisite equipment and the additional time required for diagnosis, compared with conventional white light endoscopy.

Batch Scheduling for Hybrid Assembly Differentiation Flow Shop to Minimize Total Actual Flow Time

NASA Astrophysics Data System (ADS)

Maulidya, R.; Suprayogi; Wangsaputra, R.; Halim, A. H.

2018-03-01

A hybrid assembly differentiation flow shop is a three-stage flow shop consisting of Machining, Assembly and Differentiation Stages and producing different types of products. In the machining stage, parts are processed in batches on different (unrelated) machines. In the assembly stage, each part of the different parts is assembled into an assembly product. Finally, the assembled products will further be processed into different types of final products in the differentiation stage. In this paper, we develop a batch scheduling model for a hybrid assembly differentiation flow shop to minimize the total actual flow time defined as the total times part spent in the shop floor from the arrival times until its due date. We also proposed a heuristic algorithm for solving the problems. The proposed algorithm is tested using a set of hypothetic data. The solution shows that the algorithm can solve the problems effectively.

Least-squares finite element methods for compressible Euler equations

NASA Technical Reports Server (NTRS)

Jiang, Bo-Nan; Carey, G. F.

1990-01-01

A method based on backward finite differencing in time and a least-squares finite element scheme for first-order systems of partial differential equations in space is applied to the Euler equations for gas dynamics. The scheme minimizes the L-sq-norm of the residual within each time step. The method naturally generates numerical dissipation proportional to the time step size. An implicit method employing linear elements has been implemented and proves robust. For high-order elements, computed solutions based on the L-sq method may have oscillations for calculations at similar time step sizes. To overcome this difficulty, a scheme which minimizes the weighted H1-norm of the residual is proposed and leads to a successful scheme with high-degree elements. Finally, a conservative least-squares finite element method is also developed. Numerical results for two-dimensional problems are given to demonstrate the shock resolution of the methods and compare different approaches.

Work intensity in sacroiliac joint fusion and lumbar microdiscectomy

PubMed Central

Frank, Clay; Kondrashov, Dimitriy; Meyer, S Craig; Dix, Gary; Lorio, Morgan; Kovalsky, Don; Cher, Daniel

2016-01-01

Background The evidence base supporting minimally invasive sacroiliac (SI) joint fusion (SIJF) surgery is increasing. The work relative value units (RVUs) associated with minimally invasive SIJF are seemingly low. To date, only one published study describes the relative work intensity associated with minimally invasive SIJF. No study has compared work intensity vs other commonly performed spine surgery procedures. Methods Charts of 192 patients at five sites who underwent either minimally invasive SIJF (American Medical Association [AMA] CPT® code 27279) or lumbar microdiscectomy (AMA CPT® code 63030) were reviewed. Abstracted were preoperative times associated with diagnosis and patient care, intraoperative parameters including operating room (OR) in/out times and procedure start/stop times, and postoperative care requirements. Additionally, using a visual analog scale, surgeons estimated the intensity of intraoperative care, including mental, temporal, and physical demands and effort and frustration. Work was defined as operative time multiplied by task intensity. Results Patients who underwent minimally invasive SIJF were more likely female. Mean procedure times were lower in SIJF by about 27.8 minutes (P<0.0001) and mean total OR times were lower by 27.9 minutes (P<0.0001), but there was substantial overlap across procedures. Mean preservice and post-service total labor times were longer in minimally invasive SIJF (preservice times longer by 63.5 minutes [P<0.0001] and post-service labor times longer by 20.2 minutes [P<0.0001]). The number of postoperative visits was higher in minimally invasive SIJF. Mean total service time (preoperative + OR time + postoperative) was higher in the minimally invasive SIJF group (261.5 vs 211.9 minutes, P<0.0001). Intraoperative intensity levels were higher for mental, physical, effort, and frustration domains (P<0.0001 each). After taking into account intensity, intraoperative workloads showed substantial overlap. Conclusion Compared to a commonly performed lumbar spine surgical procedure, lumbar microdiscectomy, that currently has a higher work RVU, preoperative, intraoperative, and postoperative workload for minimally invasive SIJF is higher. The work RVU for minimally invasive SIJF should be adjusted upward as the relative amount of work is comparable. PMID:27555790

Detection of minimal residual disease following induction immunochemotherapy predicts progression free survival in mantle cell lymphoma: final results of CALGB 59909

PubMed Central

Liu, Hongtao; Johnson, Jeffrey L.; Koval, Greg; Malnassy, Greg; Sher, Dorie; Damon, Lloyd E.; Hsi, Eric D.; Bucci, Donna Marie; Linker, Charles A.; Cheson, Bruce D.; Stock, Wendy

2012-01-01

Background In the present study, the prognostic impact of minimal residual disease during treatment on time to progression and overall survival was analyzed prospectively in patients with mantle cell lymphoma treated on the Cancer and Leukemia Group B 59909 clinical trial. Design and Methods Peripheral blood and bone marrow samples were collected during different phases of the Cancer and Leukemia Group B 59909 study for minimal residual disease analysis. Minimal residual disease status was determined by quantitative polymerase chain reaction of IgH and/or BCL-1/JH gene rearrangement. Correlation of minimal residual disease status with time to progression and overall survival was determined. In multivariable analysis, minimal residual disease, and other risk factors were correlated with time to progression. Results Thirty-nine patients had evaluable, sequential peripheral blood and bone marrow samples for minimal residual disease analysis. Using peripheral blood monitoring, 18 of 39 (46%) achieved molecular remission following induction therapy. The molecular remission rate increased from 46 to 74% after one course of intensification therapy. Twelve of 21 minimal residual disease positive patients (57%) progressed within three years of follow up compared to 4 of 18 (22%) molecular remission patients (P=0.049). Detection of minimal residual disease following induction therapy predicted disease progression with a hazard ratio of 3.7 (P=0.016). The 3-year probability of time to progression among those who were in molecular remission after induction chemotherapy was 82% compared to 48% in patients with detectable minimal residual disease. The prediction of time to progression by post-induction minimal residual disease was independent of other prognostic factors in multivariable analysis. Conclusions Detection of minimal residual disease following induction immunochemotherapy was an independent predictor of time to progression following immunochemotherapy and autologous stem cell transplantation for mantle cell lymphoma. The clinical trial was registered at ClinicalTrials.gov: NCT00020943. PMID:22102709

Development of resistance of mutans streptococci and Porphyromonas gingivalis to chlorhexidine digluconate and amine fluoride/stannous fluoride-containing mouthrinses, in vitro.

PubMed

Kulik, Eva M; Waltimo, Tuomas; Weiger, Roland; Schweizer, Irene; Lenkeit, Krystyna; Filipuzzi-Jenny, Elisabeth; Walter, Clemens

2015-07-01

The aim if this study was to determine the minimal inhibitory concentrations of chlorhexidine digluconate and an amine fluoride/stannous fluoride-containing mouthrinse against Porphyromonas gingivalis and mutans streptococci during an experimental long-term subinhibitory exposition. Five P. gingivalis strains and four mutans streptococci were subcultivated for 20-30 passages in subinhibitory concentrations of chlorhexidine digluconate or an amine fluoride/stannous fluoride-containing mouthrinse. Pre-passaging minimal inhibitory concentrations for chlorhexidine ranged from 0.5 to 2 mg/l for mutans streptococci and from 2 to 4 mg/l for the P. gingivalis isolates. For the amine fluoride/stannous fluoride-containing mouthrinse minimal inhibitory values from 0.125 to 0.25% for the mutans streptococci and from 0.063 to 0.125% for the P. gingivalis isolates were determined. Two- to fourfold increased minimal inhibitory concentrations against chlorhexidine were detected for two of the five P. gingivalis isolates, whereas no increase in minimal inhibitory concentrations was found for the mutans streptococci after repeated passaging through subinhibitory concentrations. Repeated exposure to subinhibitory concentrations of the amine fluoride/stannous fluoride-containing mouthrinse did not alter the minimally inhibitory concentrations of the bacterial isolates tested. Chlorhexidine and the amine fluoride/stannous fluoride-containing mouthrinse are effective inhibitory agents against the oral bacterial isolates tested. No general development of resistance against chlorhexidine or the amine fluoride/stannous fluoride-containing mouthrinse was detected. However, some strains showed potential to develop resistance against chlorhexidine after prolonged exposure. The use of chlorhexidine should be limited to short periods of time. The amine fluoride/stannous fluoride-containing mouthrinse appears to have the potential to be used on a long-term basis.

Component-Level Electronic-Assembly Repair (CLEAR) Operational Concept

NASA Technical Reports Server (NTRS)

Oeftering, Richard C.; Bradish, Martin A.; Juergens, Jeffrey R.; Lewis, Michael J.; Vrnak, Daniel R.

2011-01-01

This Component-Level Electronic-Assembly Repair (CLEAR) Operational Concept document was developed as a first step in developing the Component-Level Electronic-Assembly Repair (CLEAR) System Architecture (NASA/TM-2011-216956). The CLEAR operational concept defines how the system will be used by the Constellation Program and what needs it meets. The document creates scenarios for major elements of the CLEAR architecture. These scenarios are generic enough to apply to near-Earth, Moon, and Mars missions. The CLEAR operational concept involves basic assumptions about the overall program architecture and interactions with the CLEAR system architecture. The assumptions include spacecraft and operational constraints for near-Earth orbit, Moon, and Mars missions. This document addresses an incremental development strategy where capabilities evolve over time, but it is structured to prevent obsolescence. The approach minimizes flight hardware by exploiting Internet-like telecommunications that enables CLEAR capabilities to remain on Earth and to be uplinked as needed. To minimize crew time and operational cost, CLEAR exploits offline development and validation to support online teleoperations. Operational concept scenarios are developed for diagnostics, repair, and functional test operations. Many of the supporting functions defined in these operational scenarios are further defined as technologies in NASA/TM-2011-216956.

Testing an Emerging Paradigm in Migration Ecology Shows Surprising Differences in Efficiency between Flight Modes

PubMed Central

Duerr, Adam E.; Miller, Tricia A.; Lanzone, Michael; Brandes, Dave; Cooper, Jeff; O'Malley, Kieran; Maisonneuve, Charles; Tremblay, Junior; Katzner, Todd

2012-01-01

To maximize fitness, flying animals should maximize flight speed while minimizing energetic expenditure. Soaring speeds of large-bodied birds are determined by flight routes and tradeoffs between minimizing time and energetic costs. Large raptors migrating in eastern North America predominantly glide between thermals that provide lift or soar along slopes or ridgelines using orographic lift (slope soaring). It is usually assumed that slope soaring is faster than thermal gliding because forward progress is constant compared to interrupted progress when birds pause to regain altitude in thermals. We tested this slope-soaring hypothesis using high-frequency GPS-GSM telemetry devices to track golden eagles during northbound migration. In contrast to expectations, flight speed was slower when slope soaring and eagles also were diverted from their migratory path, incurring possible energetic costs and reducing speed of progress towards a migratory endpoint. When gliding between thermals, eagles stayed on track and fast gliding speeds compensated for lack of progress during thermal soaring. When thermals were not available, eagles minimized migration time, not energy, by choosing energetically expensive slope soaring instead of waiting for thermals to develop. Sites suited to slope soaring include ridges preferred for wind-energy generation, thus avian risk of collision with wind turbines is associated with evolutionary trade-offs required to maximize fitness of time-minimizing migratory raptors. PMID:22558166

Testing an emerging paradigm in migration ecology shows surprising differences in efficiency between flight modes.

PubMed

Duerr, Adam E; Miller, Tricia A; Lanzone, Michael; Brandes, Dave; Cooper, Jeff; O'Malley, Kieran; Maisonneuve, Charles; Tremblay, Junior; Katzner, Todd

2012-01-01

To maximize fitness, flying animals should maximize flight speed while minimizing energetic expenditure. Soaring speeds of large-bodied birds are determined by flight routes and tradeoffs between minimizing time and energetic costs. Large raptors migrating in eastern North America predominantly glide between thermals that provide lift or soar along slopes or ridgelines using orographic lift (slope soaring). It is usually assumed that slope soaring is faster than thermal gliding because forward progress is constant compared to interrupted progress when birds pause to regain altitude in thermals. We tested this slope-soaring hypothesis using high-frequency GPS-GSM telemetry devices to track golden eagles during northbound migration. In contrast to expectations, flight speed was slower when slope soaring and eagles also were diverted from their migratory path, incurring possible energetic costs and reducing speed of progress towards a migratory endpoint. When gliding between thermals, eagles stayed on track and fast gliding speeds compensated for lack of progress during thermal soaring. When thermals were not available, eagles minimized migration time, not energy, by choosing energetically expensive slope soaring instead of waiting for thermals to develop. Sites suited to slope soaring include ridges preferred for wind-energy generation, thus avian risk of collision with wind turbines is associated with evolutionary trade-offs required to maximize fitness of time-minimizing migratory raptors.

Blading Design for Axial Turbomachines

DTIC Science & Technology

1989-05-01

three- dimensional, viscous computation systems appear to have a long development period ahead, in which fluid shear stress modeling and computation time ...and n directions and T is the shear stress , As a consequence the solution time is longer than for integral methods, dependent largely on thc accuracy of...distributions over airfoils is an adaptation of thin plate deflection theory from stress analysis. At the same time , it minimizes designer effort

Evaluating the Magnitude and Duration of Cold Load Pick-up on Residential Distribution Feeders Using Multi-State Load Models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schneider, Kevin P.; Sortomme, Eric; Venkata, S. S.

The increased level of demand that is associated with the restoration of service after an outage, Cold Load Pick-Up (CLPU), can be significantly higher than pre-outage levels, even exceeding the normal distribution feeder peak demand. These high levels of demand can delay restoration efforts and in extreme cases damage equipment. The negative impacts of CLPU can be mitigated with strategies that restore the feeder in sections, minimizing the load current. The challenge for utilities is to manage the current level on critical equipment while minimizing the time to restore service to all customers. Accurately modeling CLPU events is the firstmore » step in developing improved restoration strategies that minimize restoration times. This paper presents a new method for evaluating the magnitude of the CLPU peak, and its duration, using multi-state load models. The use of multi-state load models allows for a more accurate representation of the end-use loads that are present on residential distribution feeders.« less

A 3D virtual reality simulator for training of minimally invasive surgery.

PubMed

Mi, Shao-Hua; Hou, Zeng-Gunag; Yang, Fan; Xie, Xiao-Liang; Bian, Gui-Bin

2014-01-01

For the last decade, remarkable progress has been made in the field of cardiovascular disease treatment. However, these complex medical procedures require a combination of rich experience and technical skills. In this paper, a 3D virtual reality simulator for core skills training in minimally invasive surgery is presented. The system can generate realistic 3D vascular models segmented from patient datasets, including a beating heart, and provide a real-time computation of force and force feedback module for surgical simulation. Instruments, such as a catheter or guide wire, are represented by a multi-body mass-spring model. In addition, a realistic user interface with multiple windows and real-time 3D views are developed. Moreover, the simulator is also provided with a human-machine interaction module that gives doctors the sense of touch during the surgery training, enables them to control the motion of a virtual catheter/guide wire inside a complex vascular model. Experimental results show that the simulator is suitable for minimally invasive surgery training.

The Steinberg-Bernstein Centre for Minimally Invasive Surgery at McGill University.

PubMed

Fried, Gerald M

2005-12-01

Surgical skills and simulation centers have been developed in recent years to meet the educational needs of practicing surgeons, residents, and students. The rapid pace of innovation in surgical procedures and technology, as well as the overarching desire to enhance patient safety, have driven the development of simulation technology and new paradigms for surgical education. McGill University has implemented an innovative approach to surgical education in the field of minimally invasive surgery. The goal is to measure surgical performance in the operating room using practical, reliable, and valid metrics, which allow the educational needs of the learner to be established and enable feedback and performance to be tracked over time. The GOALS system and the MISTELS program have been developed to measure operative performance and minimally invasive surgical technical skills in the inanimate skills lab, respectively. The MISTELS laparoscopic simulation-training program has been incorporated as the manual skills education and evaluation component of the Fundamentals of Laparoscopic Surgery program distributed by the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) and the American College of Surgeons.

Application of quadratic optimization to supersonic inlet control

NASA Technical Reports Server (NTRS)

Lehtinen, B.; Zeller, J. R.

1971-01-01

The application of linear stochastic optimal control theory to the design of the control system for the air intake (inlet) of a supersonic air-breathing propulsion system is discussed. The controls must maintain a stable inlet shock position in the presence of random airflow disturbances and prevent inlet unstart. Two different linear time invariant control systems are developed. One is designed to minimize a nonquadratic index, the expected frequency of inlet unstart, and the other is designed to minimize the mean square value of inlet shock motion. The quadratic equivalence principle is used to obtain the best linear controller that minimizes the nonquadratic performance index. The two systems are compared on the basis of unstart prevention, control effort requirements, and sensitivity to parameter variations.

Developing self-cleaning and air purifying transportation infrastructure components to minimize environmental impact of transportation.

DOT National Transportation Integrated Search

2013-10-01

Creating transportation infrastructure, which can clean up itself and contaminated air surrounding it, can be a : groundbreaking approach in addressing environmental challenges of our time. This project has explored a possibility of : depositing coat...

Improving the performance of minimizers and winnowing schemes

PubMed Central

Marçais, Guillaume; Pellow, David; Bork, Daniel; Orenstein, Yaron; Shamir, Ron; Kingsford, Carl

2017-01-01

Abstract Motivation: The minimizers scheme is a method for selecting k-mers from sequences. It is used in many bioinformatics software tools to bin comparable sequences or to sample a sequence in a deterministic fashion at approximately regular intervals, in order to reduce memory consumption and processing time. Although very useful, the minimizers selection procedure has undesirable behaviors (e.g. too many k-mers are selected when processing certain sequences). Some of these problems were already known to the authors of the minimizers technique, and the natural lexicographic ordering of k-mers used by minimizers was recognized as their origin. Many software tools using minimizers employ ad hoc variations of the lexicographic order to alleviate those issues. Results: We provide an in-depth analysis of the effect of k-mer ordering on the performance of the minimizers technique. By using small universal hitting sets (a recently defined concept), we show how to significantly improve the performance of minimizers and avoid some of its worse behaviors. Based on these results, we encourage bioinformatics software developers to use an ordering based on a universal hitting set or, if not possible, a randomized ordering, rather than the lexicographic order. This analysis also settles negatively a conjecture (by Schleimer et al.) on the expected density of minimizers in a random sequence. Availability and Implementation: The software used for this analysis is available on GitHub: https://github.com/gmarcais/minimizers.git. Contact: gmarcais@cs.cmu.edu or carlk@cs.cmu.edu PMID:28881970

Parturition prediction and timing of canine pregnancy

PubMed Central

Kim, YeunHee; Travis, Alexander J.; Meyers-Wallen, Vicki N.

2007-01-01

An accurate method of predicting the date of parturition in the bitch is clinically useful to minimize or prevent reproductive losses by timely intervention. Similarly, an accurate method of timing canine ovulation and gestation is critical for development of assisted reproductive technologies, e.g. estrous synchronization and embryo transfer. This review discusses present methods for accurately timing canine gestational age and outlines their use in clinical management of high-risk pregnancies and embryo transfer research. PMID:17904630

Comparison of Low-Thrust Control Laws for Application in Planetocentric Space

NASA Technical Reports Server (NTRS)

Falck, Robert D.; Sjauw, Waldy K.; Smith, David A.

2014-01-01

Recent interest at NASA for the application of solar electric propulsion for the transfer of significant payloads in cislunar space has led to the development of high-fidelity simulations of such missions. With such transfers involving transfer times on the order of months, simulation time can be significant. In the past, the examination of such missions typically began with the use of lower-fidelity trajectory optimization tools such as SEPSPOT to develop and tune guidance laws which delivered optimal or near- optimal trajectories, where optimal is generally defined as minimizing propellant expenditure or time of flight. The transfer of these solutions to a high-fidelity simulation is typically an iterative process whereby the initial solution may nearly, but not precisely, meet mission objectives. Further tuning of the guidance algorithm is typically necessary when accounting for high-fidelity perturbations such as those due to more detailed gravity models, secondary-body effects, solar radiation pressure, etc. While trajectory optimization is a useful method for determining optimal performance metrics, algorithms which deliver nearly optimal performance with minimal tuning are an attractive alternative.

The Power of Story in the Spiritual Development of Children

ERIC Educational Resources Information Center

Hoopes, Marva L.

2013-01-01

In a child's life, the church has minimal time to make a maximum impact. The time children are in church must not be wasted, but should be spent in valuable and life changing ways. Stories have long been included in Christian education, but is the practice of telling stories something that is continued merely because "we've always done it…

Rapid calculation of genomic evaluations for new animals

USDA-ARS?s Scientific Manuscript database

A method was developed to calculate preliminary genomic evaluations daily or weekly before the release of official monthly evaluations by processing only newly genotyped animals using estimates of SNP effects from the previous official evaluation. To minimize computing time, reliabilities and genomi...

75 FR 71419 - Proposed Information Collection; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-23

..., reporting burden (time and financial resources) is minimized, collection instruments are clearly understood... Community Corp's NCCC Sponsor Survey. This survey was developed to support NCCC performance measurement for... collection of information is necessary for the proper performance of the functions of the Corporation...

Preclinical development of monoclonal antibodies: considerations for the use of non-human primates.

PubMed

Chapman, Kathryn; Pullen, Nick; Coney, Lee; Dempster, Maggie; Andrews, Laura; Bajramovic, Jeffrey; Baldrick, Paul; Buckley, Lorrene; Jacobs, Abby; Hale, Geoff; Green, Colin; Ragan, Ian; Robinson, Vicky

2009-01-01

The development of mAbs remains high on the therapeutic agenda for the majority of pharmaceutical and biotechnology companies. Often, the only relevant species for preclinical safety assessment of mAbs are non-human primates (NHPs), and this raises important scientific, ethical and economic issues. To investigate evidence-based opportunities to minimize the use of NHPs, an expert working group with representatives from leading pharmaceutical and biotechnology companies, contract research organizations and institutes from Europe and the USA, has shared and analyzed data on mAbs for a range of therapeutic areas. This information has been applied to hypothetical examples to recommend scientifically appropriate development pathways and study designs for a variety of potential mAbs. The addendum of ICHS6 provides a timely opportunity for the scientific and regulatory community to embrace strategies which minimize primate use and increase efficiency of mAb development.

Method for Hot Real-Time Sampling of Gasification Products

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pomeroy, Marc D

The Thermochemical Process Development Unit (TCPDU) at the National Renewable Energy Laboratory (NREL) is a highly instrumented half-ton/day pilot scale plant capable of demonstrating industrially relevant thermochemical technologies from lignocellulosic biomass conversion, including gasification. Gasification creates primarily Syngas (a mixture of Hydrogen and Carbon Monoxide) that can be utilized with synthesis catalysts to form transportation fuels and other valuable chemicals. Biomass derived gasification products are a very complex mixture of chemical components that typically contain Sulfur and Nitrogen species that can act as catalysis poisons for tar reforming and synthesis catalysts. Real-time hot online sampling techniques, such as Molecular Beammore » Mass Spectrometry (MBMS), and Gas Chromatographs with Sulfur and Nitrogen specific detectors can provide real-time analysis providing operational indicators for performance. Sampling typically requires coated sampling lines to minimize trace sulfur interactions with steel surfaces. Other materials used inline have also shown conversion of sulfur species into new components and must be minimized. Sample line Residence time within the sampling lines must also be kept to a minimum to reduce further reaction chemistries. Solids from ash and char contribute to plugging and must be filtered at temperature. Experience at NREL has shown several key factors to consider when designing and installing an analytical sampling system for biomass gasification products. They include minimizing sampling distance, effective filtering as close to source as possible, proper line sizing, proper line materials or coatings, even heating of all components, minimizing pressure drops, and additional filtering or traps after pressure drops.« less

Real-time detection system for tumor localization during minimally invasive surgery for gastric and colon cancer removal: In vivo feasibility study in a swine model.

PubMed

Choi, Won Jung; Moon, Jin-Hee; Min, Jae Seok; Song, Yong Keun; Lee, Seung A; Ahn, Jin Woo; Lee, Sang Hun; Jung, Ha Chul

2018-03-01

During minimally invasive surgery (MIS), it is impossible to directly detect marked clips around tumors via palpation. Therefore, we developed a novel method and device using Radio Frequency IDentification (RFID) technology to detect the position of clips during minimally invasive gastrectomy or colectomy. The feasibility of the RFID-based detection system was evaluated in an animal experiment consisting of seven swine. The primary outcome was to successfully detect the location of RFID clips in the stomach and colon. The secondary outcome measures were to detect time (time during the intracorporeal detection of the RFID clip), and accuracy (distance between the RFID clip and the detected site). A total of 25 detection attempts (14 in the stomach and 11 in the colon) using the RFID antenna had a 100% success rate. The median detection time was 32.5 s (range, 15-119 s) for the stomach and 28.0 s (range, 8-87 s) for the colon. The median detection distance was 6.5 mm (range, 4-18 mm) for the stomach and 6.0 mm (range, 3-13 mm) for the colon. We demonstrated favorable results for a RFID system that detects the position of gastric and colon tumors in real-time during MIS. © 2017 Wiley Periodicals, Inc.

Typical Toddlers' Participation in "Just-in-Time" Programming of Vocabulary for Visual Scene Display Augmentative and Alternative Communication Apps on Mobile Technology: A Descriptive Study.

PubMed

Holyfield, Christine; Drager, Kathryn; Light, Janice; Caron, Jessica Gosnell

2017-08-15

Augmentative and alternative communication (AAC) promotes communicative participation and language development for young children with complex communication needs. However, the motor, linguistic, and cognitive demands of many AAC technologies restrict young children's operational use of and influence over these technologies. The purpose of the current study is to better understand young children's participation in programming vocabulary "just in time" on an AAC application with minimized demands. A descriptive study was implemented to highlight the participation of 10 typically developing toddlers (M age: 16 months, range: 10-22 months) in just-in-time vocabulary programming in an AAC app with visual scene displays. All 10 toddlers participated in some capacity in adding new visual scene displays and vocabulary to the app just in time. Differences in participation across steps were observed, suggesting variation in the developmental demands of controls involved in vocabulary programming. Results from the current study provide clinical insights toward involving young children in AAC programming just in time and steps that may allow for more independent participation or require more scaffolding. Technology designed to minimize motor, cognitive, and linguistic demands may allow children to participate in programming devices at a younger age.

Communication growth in minimally verbal children with ASD: The importance of interaction.

PubMed

DiStefano, Charlotte; Shih, Wendy; Kaiser, Ann; Landa, Rebecca; Kasari, Connie

2016-10-01

Little is known about language development in children with Autism Spectrum Disorders (ASD) who remain minimally verbal past age 5. While there is evidence that children can develop language after age 5, we lack detailed information. Studies of this population generally focus on discrete language skills without addressing broader social-communication abilities. As communication and social deficits are both inherent to ASD, an examination of not only what language skills are acquired, but how those skills are used in interactions is relevant. Research in typical development has examined how communication interchanges (unbroken back-and-forth exchanges around a unified purpose) develop, which can be used as a framework for studying minimally verbal children. This study examined the interchange use by 55 children with ASD over the course of a 6-month play and engagement-based communication intervention. Half of the children received intervention sessions that also incorporated a speech-generating device (SGD). Interchanges were coded by: frequency, length, function, and initiator (child or adult). Results indicated that children initiated a large proportion of interchanges and this proportion increased over time. The average length and number of interchanges increased over time, with children in the SGD group showing even greater growth. Finally, children's total number of interchanges at baseline was positively associated with their spoken language gains over the course of intervention. This study supports the crucial relationship between social engagement and expressive language development, and highlights the need to include sustained communication interchanges as a target for intervention with this population. Autism Res 2016, 9: 1093-1102. © 2016 International Society for Autism Research, Wiley Periodicals, Inc. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.

Artificial Intelligence in Autonomous Telescopes

NASA Astrophysics Data System (ADS)

Mahoney, William; Thanjavur, Karun

2011-03-01

Artificial Intelligence (AI) is key to the natural evolution of today's automated telescopes to fully autonomous systems. Based on its rapid development over the past five decades, AI offers numerous, well-tested techniques for knowledge based decision making essential for real-time telescope monitoring and control, with minimal - and eventually no - human intervention. We present three applications of AI developed at CFHT for monitoring instantaneous sky conditions, assessing quality of imaging data, and a prototype for scheduling observations in real-time. Closely complementing the current remote operations at CFHT, we foresee further development of these methods and full integration in the near future.

Analysis of research ethics board approval times in an academic department of medicine.

PubMed

Tsang, Teresa S M; Jones, Meaghan; Meneilly, Graydon S

2015-04-01

As part of an ongoing effort to better understand barriers to academic research, we reviewed and analyzed the process of research ethics applications, focusing on ethics approval time, within the Department of Medicine from 2006 to 2011. A total of 1,268 applications for approval to use human subjects in research were included in our analysis. Three variables, risk category (minimal vs. non-minimal risk), type of funding, and year of submission, were statistically significant for prediction of ethics approval time, with risk status being the most important of these. The covariate-adjusted mean time for approval for minimal risk studies (35.7 days) was less than half that of non-minimal risk protocols (76.5 days). Studies funded through a for-profit sponsor had significantly longer approval times than those funded through other means but were also predominantly (87%) non-minimal risk protocols. Further investigations of the reasons underlying the observed differences are needed to determine whether improved training for research ethics board (REB) members and/or greater dialogue with investigators may reduce the lengthy approval times associated with non-minimal risk protocols. © The Author(s) 2015.

Blackfolds, plane waves and minimal surfaces

NASA Astrophysics Data System (ADS)

Armas, Jay; Blau, Matthias

2015-07-01

Minimal surfaces in Euclidean space provide examples of possible non-compact horizon geometries and topologies in asymptotically flat space-time. On the other hand, the existence of limiting surfaces in the space-time provides a simple mechanism for making these configurations compact. Limiting surfaces appear naturally in a given space-time by making minimal surfaces rotate but they are also inherent to plane wave or de Sitter space-times in which case minimal surfaces can be static and compact. We use the blackfold approach in order to scan for possible black hole horizon geometries and topologies in asymptotically flat, plane wave and de Sitter space-times. In the process we uncover several new configurations, such as black helicoids and catenoids, some of which have an asymptotically flat counterpart. In particular, we find that the ultraspinning regime of singly-spinning Myers-Perry black holes, described in terms of the simplest minimal surface (the plane), can be obtained as a limit of a black helicoid, suggesting that these two families of black holes are connected. We also show that minimal surfaces embedded in spheres rather than Euclidean space can be used to construct static compact horizons in asymptotically de Sitter space-times.

[Haptic tracking control for minimally invasive robotic surgery].

PubMed

Xu, Zhaohong; Song, Chengli; Wu, Wenwu

2012-06-01

Haptic feedback plays a significant role in minimally invasive robotic surgery (MIRS). A major deficiency of the current MIRS is the lack of haptic perception for the surgeon, including the commercially available robot da Vinci surgical system. In this paper, a dynamics model of a haptic robot is established based on Newton-Euler method. Because it took some period of time in exact dynamics solution, we used a digital PID arithmetic dependent on robot dynamics to ensure real-time bilateral control, and it could improve tracking precision and real-time control efficiency. To prove the proposed method, an experimental system in which two Novint Falcon haptic devices acting as master-slave system has been developed. Simulations and experiments showed proposed methods could give instrument force feedbacks to operator, and bilateral control strategy is an effective method to master-slave MIRS. The proposed methods could be used to tele-robotic system.

Development of a Method to Produce Freeze-Dried Cubes from 3 Pacific Salmon Species

USDA-ARS?s Scientific Manuscript database

Freeze-dried boneless skinless cubes of pink (Oncorhynchus gorbuscha), sockeye (Oncorhynchus nerka), and chum (Oncorhynchus keta) salmon were prepared and physical properties evaluated. To minimize freeze-drying time, the kinetics of dehydration and processing yields were investigated. The physical ...

Combined-cycle plant built in record time

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1995-04-01

This article reports that this low-cost cogeneration plant meets residential community`s environmental concerns with noise minimization, emissions control, and zero wastewater discharge. Supplying electricity to the local utility and steam to two hosts, the Auburndale cogeneration facility embodies the ``reference plant`` design approach developed by Westinghouse Power Generation (WPG), Orlando, Fla. With this approach customers meet their particular needs by choosing from a standard package of plant equipment and design options. Main goals of the concept are reduced construction time efficient and reliable power generation, minimal operating staff, and low cost. WPG built the plant on a turnkey basis formore » Auburndale Power Partners Limited Partnership (APP). APP is a partially owned subsidiary of Mission Energy, a California-based international developer and operator of independent-power facilities. The cogeneration facility supplies 150 MW of electric power to Florida Power Corp and exports 120,000 lb/hr of steam to Florida Distillers Co and Coca-Cola Foods.« less

Minimizing Segregation During the Controlled Directional Solidification of Dendritic Alloys Publication: Metallurgical and Materials Transactions

NASA Technical Reports Server (NTRS)

Grugel, R. N.; Fedoseyev, A. I.; Kim, S.; Curreri, Peter A. (Technical Monitor)

2002-01-01

Gravity-driven thermosolutal convection that arises during controlled directional solidification (DS) of dendritic alloys promotes detrimental macro-segregation (e.g. freckles and steepling) in products such as turbine blades. Considerable time and effort has been spent to experimentally and theoretically investigate this phenomena; although our knowledge has advanced to the point where convection can be modeled and accurately compared to experimental results, little has been done to minimize its onset and deleterious effects. The experimental work demonstrates that segregation can be. minimized and microstructural uniformity promoted when a slow axial rotation is applied to the sample crucible during controlled directional solidification processing. Numerical modeling utilizing continuation and bifurcation methods have been employed to develop accurate physical and mathematical models with the intent of identifying and optimizing processing parameters.

Real-Time Control of Lean Blowout in a Turbine Engine for Minimizing No(x) Emissions

NASA Technical Reports Server (NTRS)

Zinn, Ben

2004-01-01

This report describes research on the development and demonstration of a controlled combustor operates with minimal NO, emissions, thus meeting one of NASA s UEET program goals. NO(x) emissions have been successfully minimized by operating a premixed, lean burning combustor (modeling a lean prevaporized, premixed LPP combustor) safely near its lean blowout (LBO) limit over a range of operating conditions. This was accomplished by integrating the combustor with an LBO precursor sensor and closed-loop, rule-based control system that allowed the combustor to operate far closer to the point of LBO than an uncontrolled combustor would be allowed to in a current engine. Since leaner operation generally leads to lower NO, emissions, engine NO, was reduced without loss of safety.

Improving the performance of minimizers and winnowing schemes.

PubMed

Marçais, Guillaume; Pellow, David; Bork, Daniel; Orenstein, Yaron; Shamir, Ron; Kingsford, Carl

2017-07-15

The minimizers scheme is a method for selecting k -mers from sequences. It is used in many bioinformatics software tools to bin comparable sequences or to sample a sequence in a deterministic fashion at approximately regular intervals, in order to reduce memory consumption and processing time. Although very useful, the minimizers selection procedure has undesirable behaviors (e.g. too many k -mers are selected when processing certain sequences). Some of these problems were already known to the authors of the minimizers technique, and the natural lexicographic ordering of k -mers used by minimizers was recognized as their origin. Many software tools using minimizers employ ad hoc variations of the lexicographic order to alleviate those issues. We provide an in-depth analysis of the effect of k -mer ordering on the performance of the minimizers technique. By using small universal hitting sets (a recently defined concept), we show how to significantly improve the performance of minimizers and avoid some of its worse behaviors. Based on these results, we encourage bioinformatics software developers to use an ordering based on a universal hitting set or, if not possible, a randomized ordering, rather than the lexicographic order. This analysis also settles negatively a conjecture (by Schleimer et al. ) on the expected density of minimizers in a random sequence. The software used for this analysis is available on GitHub: https://github.com/gmarcais/minimizers.git . gmarcais@cs.cmu.edu or carlk@cs.cmu.edu. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

Primary Hyperparathyroidism in Older People: Surgical Treatment with Minimally Invasive Approaches and Outcome

PubMed Central

Dobrinja, Chiara; Silvestri, Marta; de Manzini, Nicolò

2012-01-01

Introduction. Elderly patients with primary hyperparathyroidism (pHPT) are often not referred to surgery because of their associated comorbidities that may increase surgical risk. The aim of the study was to review indications and results of minimally invasive approach parathyroidectomy in elderly patients to evaluate its impact on outcome. Materials and Methods. All patients of 70 years of age or older undergoing minimally approach parathyroidectomy at our Department from May 2005 to May 2011 were reviewed. Data collected included patients demographic information, biochemical pathology, time elapsed from pHPT diagnosis to surgical intervention, operative findings, complications, and results of postoperative biochemical studies. Results and Discussion. 37 patients were analysed. The average length of stay was 2.8 days. 11 patients were discharged within 24 hours after their operation. Morbidity included 6 transient symptomatic postoperative hypocalcemias while one patient developed a transient laryngeal nerve palsy. Time elapsed from pHPT diagnosis to first surgical visit evidences that the elderly patients were referred after their disease had progressed. Conclusions. Our data show that minimally invasive approach to parathyroid surgery seems to be safe and curative also in elderly patients with few associated risks because of combination of modern preoperative imaging, advances in surgical technique, and advances in anesthesia care. PMID:22737167

A novel method to estimate safety factor of capture by a fetal micropacemaker.

PubMed

Vest, Adriana Nicholson; Zhou, Li; Bar-Cohen, Yaniv; Eli Loeb, Gerald

2016-07-01

We have developed a rechargeable fetal micropacemaker in order to treat severe fetal bradycardia with comorbid hydrops fetalis, a life-threatening condition in pre-term non-viable fetuses for which there are no effective treatment options. The small size and minimally invasive form factor of our design limit the volume available for circuitry and a power source. The device employs a fixed-rate and fixed-amplitude relaxation oscillator and a tiny, rechargeable lithium ion power cell. For both research and clinical applications, it is valuable to monitor the electrode-myocardium interface in order to determine that adequate pacemaker output is being provided. This is typically accomplished by observing the minimal stimulus strength that achieves threshold for pacing capture. The output of our simple micropacemaker cannot be programmatically altered to determine this minimal capture threshold, but a safety factor can be inferred by determining the refractory period for ventricular capture at a given stimulus strength. This is done by measuring the minimal timing between naturally occurring QRS complexes and pacing stimuli that successfully generate a premature ventricular contraction. The method was tested in a pilot study in four fetal sheep and the data demonstrate that a relative measure of threshold is obtainable. This method provides valuable real-time information about the electrode-tissue interface.

A novel method to estimate safety factor of capture by a fetal micropacemaker

PubMed Central

Vest, Adriana Nicholson; Zhou, Li; Bar-Cohen, Yaniv; Loeb, Gerald Eli

2016-01-01

We have developed a rechargeable fetal micropacemaker in order to treat severe fetal bradycardia with comorbid hydrops fetalis, a life-threatening condition in pre-term non-viable fetuses for which there are no effective treatment options. The small size and minimally invasive form factor of our design limit the volume available for circuitry and a power source. The device employs a fixed-rate and fixed-amplitude relaxation oscillator and a tiny, rechargeable lithium ion power cell. For both research and clinical applications, it is valuable to monitor the electrode-myocardium interface in order to determine that adequate pacemaker output is being provided. This is typically accomplished by observing the minimal stimulus strength that achieves threshold for pacing capture. The output of our simple micropacemaker cannot be programmatically altered to determine this minimal capture threshold, but a safety factor can be inferred by determining the refractory period for ventricular capture at a given stimulus strength. This is done by measuring the minimal timing between naturally occurring QRS complexes and pacing stimuli that successfully generate a premature ventricular contraction. The method was tested in a pilot study in 4 fetal sheep and the data demonstrate that a relative measure of threshold is obtainable. This method provides valuable real-time information about the electrode-tissue interface. PMID:27340134

A randomized prospective study of desflurane versus isoflurane in minimal flow anesthesia using “equilibration time” as the change-over point to minimal flow

PubMed Central

Mallik, Tanuja; Aneja, S; Tope, R; Muralidhar, V

2012-01-01

Background: In the administration of minimal flow anesthesia, traditionally a fixed time period of high flow has been used before changing over to minimal flow. However, newer studies have used “equilibration time” of a volatile anesthetic agent as the change-over point. Materials and Methods: A randomized prospective study was conducted on 60 patients, who were divided into two groups of 30 patients each. Two volatile inhalational anesthetic agents were compared. Group I received desflurane (n = 30) and group II isoflurane (n = 30). Both the groups received an initial high flow till equilibration between inspired (Fi) and expired (Fe) agent concentration were achieved, which was defined as Fe/Fi = 0.8. The mean (SD) equilibration time was obtained for both the agent. Then, a drift in end-tidal agent concentration during the minimal flow anesthesia and recovery profile was noted. Results: The mean equilibration time obtained for desflurane and isoflurane were 4.96 ± 1.60 and 16.96 ± 9.64 min (P < 0.001). The drift in end-tidal agent concentration over time was minimal in the desflurane group (P = 0.065). Recovery time was 5.70 ± 2.78 min in the desflurane group and 8.06 ± 31 min in the isoflurane group (P = 0.004). Conclusion: Use of equilibration time of the volatile anesthetic agent as a change-over point, from high flow to minimal flow, can help us use minimal flow anesthesia, in a more efficient way. PMID:23225926

Iterated greedy algorithms to minimize the total family flow time for job-shop scheduling with job families and sequence-dependent set-ups

NASA Astrophysics Data System (ADS)

Kim, Ji-Su; Park, Jung-Hyeon; Lee, Dong-Ho

2017-10-01

This study addresses a variant of job-shop scheduling in which jobs are grouped into job families, but they are processed individually. The problem can be found in various industrial systems, especially in reprocessing shops of remanufacturing systems. If the reprocessing shop is a job-shop type and has the component-matching requirements, it can be regarded as a job shop with job families since the components of a product constitute a job family. In particular, sequence-dependent set-ups in which set-up time depends on the job just completed and the next job to be processed are also considered. The objective is to minimize the total family flow time, i.e. the maximum among the completion times of the jobs within a job family. A mixed-integer programming model is developed and two iterated greedy algorithms with different local search methods are proposed. Computational experiments were conducted on modified benchmark instances and the results are reported.

Insights into a microwave susceptible agent for minimally invasive microwave tumor thermal therapy.

PubMed

Shi, Haitang; Liu, Tianlong; Fu, Changhui; Li, Linlin; Tan, Longfei; Wang, Jingzhuo; Ren, Xiangling; Ren, Jun; Wang, Jianxin; Meng, Xianwei

2015-03-01

This work develops a kind of sodium alginate (SA) microcapsules as microwave susceptible agents for in vivo tumor microwave thermal therapy for the first time. Due to the excellent microwave susceptible properties and low bio-toxicity, excellent therapy efficiency can be achieved with the tumor inhibiting ratio of 97.85% after one-time microwave thermal therapy with ultralow power (1.8 W, 450 MHz). Meanwhile, the mechanism of high microwave heating efficiency was confirmed via computer-simulated model in theory, demonstrating that the spatial confinement efficiency of microcapsule walls endows the inside ions with high microwave susceptible properties. This strategy offers tremendous potential applications in clinical tumor treatment with the benefits of safety, reliability, effectiveness and minimally invasiveness. Copyright © 2014 Elsevier Ltd. All rights reserved.

Root Cause Analysis of Sexual Assault: Shifting from Early Detection to a Vaccine

DTIC Science & Technology

2015-02-17

Women Bystander Behavior Basic Development /Personal Identity Sexuality Pornography Dating STDs/Communicable Diseases He Said/She Said - Mars vs Venus...trust over time and sharing of current life experiences allows for “ developmental coaching” (CCLD, “ Developing Leaders,” 21) in a safe environment...skill development . Just as root sources for cancer are mitigated by not smoking, minimal sun exposure, adopting healthy eating habits and alcohol use

The minimal scenario of leptogenesis

NASA Astrophysics Data System (ADS)

Blanchet, Steve; Di Bari, Pasquale

2012-12-01

We review the main features and results of thermal leptogenesis within the type I seesaw mechanism, the minimal extension of the Standard Model explaining neutrino masses and mixing. After presenting the simplest approach, the vanilla scenario, we discuss various important developments of recent years, such as the inclusion of lepton and heavy neutrino flavour effects, a description beyond a hierarchical heavy neutrino mass spectrum and an improved kinetic description within the density matrix and the closed-time-path formalisms. We also discuss how leptogenesis can ultimately represent an important phenomenological tool to test the seesaw mechanism and the underlying model of new physics.

Multilayer mounting for long-term light sheet microscopy of zebrafish.

PubMed

Weber, Michael; Mickoleit, Michaela; Huisken, Jan

2014-02-27

Light sheet microscopy is the ideal imaging technique to study zebrafish embryonic development. Due to minimal photo-toxicity and bleaching, it is particularly suited for long-term time-lapse imaging over many hours up to several days. However, an appropriate sample mounting strategy is needed that offers both confinement and normal development of the sample. Multilayer mounting, a new embedding technique using low-concentration agarose in optically clear tubes, now overcomes this limitation and unleashes the full potential of light sheet microscopy for real-time developmental biology.

Multilayer Mounting for Long-term Light Sheet Microscopy of Zebrafish

PubMed Central

Weber, Michael; Mickoleit, Michaela; Huisken, Jan

2014-01-01

Light sheet microscopy is the ideal imaging technique to study zebrafish embryonic development. Due to minimal photo-toxicity and bleaching, it is particularly suited for long-term time-lapse imaging over many hours up to several days. However, an appropriate sample mounting strategy is needed that offers both confinement and normal development of the sample. Multilayer mounting, a new embedding technique using low-concentration agarose in optically clear tubes, now overcomes this limitation and unleashes the full potential of light sheet microscopy for real-time developmental biology. PMID:24637614

Orbital Battleship: A Guessing Game to Reinforce Atomic Structure

ERIC Educational Resources Information Center

Kurushkin, Mikhail; Mikhaylenko, Maria

2016-01-01

A competitive educational guessing game "Orbital Battleship" which reinforces Madelung's and Hund's rules, values of quantum numbers, and understanding of periodicity was designed. The game develops strategic thinking, is not time-consuming, requires minimal preparation and supervision, and is an efficient and fun alternative to more…

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Hao; Garzoglio, Gabriele; Ren, Shangping

FermiCloud is a private cloud developed in Fermi National Accelerator Laboratory to provide elastic and on-demand resources for different scientific research experiments. The design goal of the FermiCloud is to automatically allocate resources for different scientific applications so that the QoS required by these applications is met and the operational cost of the FermiCloud is minimized. Our earlier research shows that VM launching overhead has large variations. If such variations are not taken into consideration when making resource allocation decisions, it may lead to poor performance and resource waste. In this paper, we show how we may use an VMmore » launching overhead reference model to minimize VM launching overhead. In particular, we first present a training algorithm that automatically tunes a given refer- ence model to accurately reflect FermiCloud environment. Based on the tuned reference model for virtual machine launching overhead, we develop an overhead-aware-best-fit resource allocation algorithm that decides where and when to allocate resources so that the average virtual machine launching overhead is minimized. The experimental results indicate that the developed overhead-aware-best-fit resource allocation algorithm can significantly improved the VM launching time when large number of VMs are simultaneously launched.« less

A network-based approach for resistance transmission in bacterial populations.

PubMed

Gehring, Ronette; Schumm, Phillip; Youssef, Mina; Scoglio, Caterina

2010-01-07

Horizontal transfer of mobile genetic elements (conjugation) is an important mechanism whereby resistance is spread through bacterial populations. The aim of our work is to develop a mathematical model that quantitatively describes this process, and to use this model to optimize antimicrobial dosage regimens to minimize resistance development. The bacterial population is conceptualized as a compartmental mathematical model to describe changes in susceptible, resistant, and transconjugant bacteria over time. This model is combined with a compartmental pharmacokinetic model to explore the effect of different plasma drug concentration profiles. An agent-based simulation tool is used to account for resistance transfer occurring when two bacteria are adjacent or in close proximity. In addition, a non-linear programming optimal control problem is introduced to minimize bacterial populations as well as the drug dose. Simulation and optimization results suggest that the rapid death of susceptible individuals in the population is pivotal in minimizing the number of transconjugants in a population. This supports the use of potent antimicrobials that rapidly kill susceptible individuals and development of dosage regimens that maintain effective antimicrobial drug concentrations for as long as needed to kill off the susceptible population. Suggestions are made for experiments to test the hypotheses generated by these simulations.

Influence of regeneration method and tissue source on the frequency of somatic variation in Populus to infection by Septoria musiva

Treesearch

Michael E. Ostry; Ronald L. Hackett; Charles H. Michler; R. Serres; B. McCown

1994-01-01

Septoria leaf spot and canker are serious diseases of many hybrid poplar clones in plantations established for biomass production. Developing resistant clones through breeding is the best long-term strategy to minimize tree damage caused by this disease. Tissue culture and somaclonal selection techniques may reduce the time needed to develop disease resistance in...

Giant saltation on Mars

PubMed Central

Almeida, Murilo P.; Parteli, Eric J. R.; Andrade, José S.; Herrmann, Hans J.

2008-01-01

Saltation, the motion of sand grains in a sequence of ballistic trajectories close to the ground, is a major factor for surface erosion, dune formation, and triggering of dust storms on Mars. Although this mode of sand transport has been matter of research for decades through both simulations and wind tunnel experiments under Earth and Mars conditions, it has not been possible to provide accurate measurements of particle trajectories in fully developed turbulent flow. Here we calculate the motion of saltating grains by directly solving the turbulent wind field and its interaction with the particles. Our calculations show that the minimal wind velocity required to sustain saltation on Mars may be surprisingly lower than the aerodynamic minimal threshold measurable in wind tunnels. Indeed, Mars grains saltate in 100 times higher and longer trajectories and reach 5-10 times higher velocities than Earth grains do. On the basis of our results, we arrive at general expressions that can be applied to calculate the length and height of saltation trajectories and the flux of grains in saltation under various physical conditions, when the wind velocity is close to the minimal threshold for saltation. PMID:18443302

LSST: Cadence Design and Simulation

NASA Astrophysics Data System (ADS)

Cook, Kem H.; Pinto, P. A.; Delgado, F.; Miller, M.; Petry, C.; Saha, A.; Gee, P. A.; Tyson, J. A.; Ivezic, Z.; Jones, L.; LSST Collaboration

2009-01-01

The LSST Project has developed an operations simulator to investigate how best to observe the sky to achieve its multiple science goals. The simulator has a sophisticated model of the telescope and dome to properly constrain potential observing cadences. This model has also proven useful for investigating various engineering issues ranging from sizing of slew motors, to design of cryogen lines to the camera. The simulator is capable of balancing cadence goals from multiple science programs, and attempts to minimize time spent slewing as it carries out these goals. The operations simulator has been used to demonstrate a 'universal' cadence which delivers the science requirements for a deep cosmology survey, a Near Earth Object Survey and good sampling in the time domain. We will present the results of simulating 10 years of LSST operations using realistic seeing distributions, historical weather data, scheduled engineering downtime and current telescope and camera parameters. These simulations demonstrate the capability of the LSST to deliver a 25,000 square degree survey probing the time domain including 20,000 square degrees for a uniform deep, wide, fast survey, while effectively surveying for NEOs over the same area. We will also present our plans for future development of the simulator--better global minimization of slew time and eventual transition to a scheduler for the real LSST.

The evolution of endovascular electroencephalography: historical perspective and future applications.

PubMed

Sefcik, Roberta K; Opie, Nicholas L; John, Sam E; Kellner, Christopher P; Mocco, J; Oxley, Thomas J

2016-05-01

Current standard practice requires an invasive approach to the recording of electroencephalography (EEG) for epilepsy surgery, deep brain stimulation (DBS), and brain-machine interfaces (BMIs). The development of endovascular techniques offers a minimally invasive route to recording EEG from deep brain structures. This historical perspective aims to describe the technical progress in endovascular EEG by reviewing the first endovascular recordings made using a wire electrode, which was followed by the development of nanowire and catheter recordings and, finally, the most recent progress in stent-electrode recordings. The technical progress in device technology over time and the development of the ability to record chronic intravenous EEG from electrode arrays is described. Future applications for the use of endovascular EEG in the preoperative and operative management of epilepsy surgery are then discussed, followed by the possibility of the technique's future application in minimally invasive operative approaches to DBS and BMI.

Software for Optimizing Quality Assurance of Other Software

NASA Technical Reports Server (NTRS)

Feather, Martin; Cornford, Steven; Menzies, Tim

2004-01-01

Software assurance is the planned and systematic set of activities that ensures that software processes and products conform to requirements, standards, and procedures. Examples of such activities are the following: code inspections, unit tests, design reviews, performance analyses, construction of traceability matrices, etc. In practice, software development projects have only limited resources (e.g., schedule, budget, and availability of personnel) to cover the entire development effort, of which assurance is but a part. Projects must therefore select judiciously from among the possible assurance activities. At its heart, this can be viewed as an optimization problem; namely, to determine the allocation of limited resources (time, money, and personnel) to minimize risk or, alternatively, to minimize the resources needed to reduce risk to an acceptable level. The end result of the work reported here is a means to optimize quality-assurance processes used in developing software.

Software for Analyzing Laminar-to-Turbulent Flow Transitions

NASA Technical Reports Server (NTRS)

Chang, Chau-Lyan

2004-01-01

Software assurance is the planned and systematic set of activities that ensures that software processes and products conform to requirements, standards, and procedures. Examples of such activities are the following: code inspections, unit tests, design reviews, performance analyses, construction of traceability matrices, etc. In practice, software development projects have only limited resources (e.g., schedule, budget, and availability of personnel) to cover the entire development effort, of which assurance is but a part. Projects must therefore select judiciously from among the possible assurance activities. At its heart, this can be viewed as an optimization problem; namely, to determine the allocation of limited resources (time, money, and personnel) to minimize risk or, alternatively, to minimize the resources needed to reduce risk to an acceptable level. The end result of the work reported here is a means to optimize quality-assurance processes used in developing software. This is achieved by combining two prior programs in an innovative manner

Implementing real-time robotic systems using CHIMERA II

NASA Technical Reports Server (NTRS)

Stewart, David B.; Schmitz, Donald E.; Khosla, Pradeep K.

1990-01-01

A description is given of the CHIMERA II programming environment and operating system, which was developed for implementing real-time robotic systems. Sensor-based robotic systems contain both general- and special-purpose hardware, and thus the development of applications tends to be a time-consuming task. The CHIMERA II environment is designed to reduce the development time by providing a convenient software interface between the hardware and the user. CHIMERA II supports flexible hardware configurations which are based on one or more VME-backplanes. All communication across multiple processors is transparent to the user through an extensive set of interprocessor communication primitives. CHIMERA II also provides a high-performance real-time kernel which supports both deadline and highest-priority-first scheduling. The flexibility of CHIMERA II allows hierarchical models for robot control, such as NASREM, to be implemented with minimal programming time and effort.

Sideband Algorithm for Automatic Wind Turbine Gearbox Fault Detection and Diagnosis: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zappala, D.; Tavner, P.; Crabtree, C.

2013-01-01

Improving the availability of wind turbines (WT) is critical to minimize the cost of wind energy, especially for offshore installations. As gearbox downtime has a significant impact on WT availabilities, the development of reliable and cost-effective gearbox condition monitoring systems (CMS) is of great concern to the wind industry. Timely detection and diagnosis of developing gear defects within a gearbox is an essential part of minimizing unplanned downtime of wind turbines. Monitoring signals from WT gearboxes are highly non-stationary as turbine load and speed vary continuously with time. Time-consuming and costly manual handling of large amounts of monitoring data representmore » one of the main limitations of most current CMSs, so automated algorithms are required. This paper presents a fault detection algorithm for incorporation into a commercial CMS for automatic gear fault detection and diagnosis. The algorithm allowed the assessment of gear fault severity by tracking progressive tooth gear damage during variable speed and load operating conditions of the test rig. Results show that the proposed technique proves efficient and reliable for detecting gear damage. Once implemented into WT CMSs, this algorithm can automate data interpretation reducing the quantity of information that WT operators must handle.« less

32 CFR 32.21 - Standards for financial management systems.

Code of Federal Regulations, 2010 CFR

2010-07-01

.... For awards that support research, it should be noted that it is generally not appropriate to develop... that support research. (5) Written procedures to minimize the time elapsing between the transfer of... Cash Management Improvement Act (CMIA) (Pub. L. 101-453) govern, payment methods of State agencies...

Planned Missing Data Designs for Research in Cognitive Development

ERIC Educational Resources Information Center

Rhemtulla, Mijke; Little, Todd D.

2012-01-01

Data collection can be the most time- and cost-intensive part of developmental research. This article describes some long-proposed but little-used research designs that have the potential to maximize data quality (reliability and validity) while minimizing research cost. In "planned missing data designs", missing data are used…

Developing a Successful Asynchronous Online Extension Program for Forest Landowners

ERIC Educational Resources Information Center

Zobrist, Kevin W.

2014-01-01

Asynchronous online Extension classes can reach a wide audience, is convenient for the learner, and minimizes ongoing demands on instructor time. However, producing such classes takes significant effort up front. Advance planning and good communication with contributors are essential to success. Considerations include delivery platforms, content…

Perioperative Events and Complications in Minimally Invasive Live Donor Nephrectomy: A Systematic Review and Meta-Analysis.

PubMed

Kortram, Kirsten; Ijzermans, Jan N M; Dor, Frank J M F

2016-11-01

Minimally invasive live donor nephrectomy has become a fully implemented and accepted procedure. Donors have to be well educated about all risks and details during the informed consent process. For this to be successful, more information regarding short-term outcome is necessary. A literature search was performed; all studies discussing short-term complications after minimally invasive live donor nephrectomy were included. Outcomes evaluated were intraoperative and postoperative complications, conversions, operative and warm ischemia times, blood loss, length of hospital stay, pain score, convalescence, quality of life, and costs. One hundred ninety articles were included in the systematic review, 41 in the meta-analysis. Conversion rate was 1.1%. Intraoperative complication rate was 2.3%, mainly bleeding (1.5%). Postoperative complications occurred in 7.3% of donors, including infectious complications (2.6%), of which mainly wound infection (1.6%) and bleeding (1.0%). Reported mortality rate was 0.01%. All minimally invasive techniques were comparable with regard to complication or conversion rate. The used techniques for minimally invasive live donor nephrectomy are safe and associated with low complication rates and minimal risk of mortality. These data may be helpful to develop a standardized, donor-tailored informed consent procedure for live donor nephrectomy.

UV gated Raman spectroscopy for standoff detection of explosives

NASA Astrophysics Data System (ADS)

Gaft, M.; Nagli, L.

2008-07-01

Real-time detection and identification of explosives at a standoff distance is a major issue in efforts to develop defense against so-called improvised explosive devices (IED). It is recognized that the only method, which is potentially capable to standoff detection of minimal amounts of explosives is laser-based spectroscopy. LDS technique belongs to trace detection, namely to its micro-particles variety. It is based on commonly held belief that surface contamination was very difficult to avoid and could be exploited for standoff detection. We have applied gated Raman spectroscopy for detection of main explosive materials, both factory and homemade. We developed and tested a Raman system for the field remote detection and identification of minimal amounts of explosives on relevant surfaces at a distance of up to 30 m.

Development and Execution of End-of-Mission Operations Case Study of the UARS and ERBS End-of-Mission Plans

NASA Technical Reports Server (NTRS)

Hughes, John; Marius, Julio L.; Montoro, Manuel; Patel, Mehul; Bludworth, David

2006-01-01

This Paper is a case study of the development and execution of the End-of-Mission plans for the Earth Radiation Budget Satellite (ERBS) and the Upper Atmosphere Research Satellite (UARS). The goals of the End-of-Mission Plans are to minimize the time the spacecraft remains on orbit and to minimize the risk of creating orbital debris. Both of these Missions predate the NASA Management Instructions (NMI) that directs missions to provide for safe mission termination. Each spacecrafts had their own unique challenges, which required assessing End-of-Mission requirements versus spacecraft limitations. Ultimately the End-of- Mission operations were about risk mitigation. This paper will describe the operational challenges and the lessons learned executing these End-of-Mission Plans

Silicon Valley as an Early Adopter for On-Demand Civil VTOL Operations

NASA Technical Reports Server (NTRS)

Antcliff, Kevin R.; Moore, Mark D.; Goodrich, Kenneth H.

2016-01-01

With high incomes, long commutes, severe ground geographic constraints, severe highway congestion during peak commute times, high housing costs, and near perfect year-round weather, the Silicon Valley is positioned to be an excellent early adopter market for emerging aviation On-Demand Mobility transportation solutions. Prior efforts have attempted to use existing aviation platforms (helicopters or General Aviation aircraft) with existing infrastructure solutions, or only investigated new vehicle platforms without understanding how to incorporate new vehicle types into existing built-up communities. Research has been performed with the objective of minimizing door-to-door time for "Hyper Commuters" (frequent, long-distance commuters) in the Silicon Valley through the development of new helipad infrastructure for ultra-low noise Vertical Takeoff and Landing (VTOL) aircraft. Current travel times for chosen city-pairs across urban and suburban commutes are compared to future mobility concepts that provide significantly higher utilization and productivity to yield competitive operating costs compared to existing transportation choices. Helipads are introduced near current modes of transportation and infrastructure for ease-of-access, and maximizing proximity. Strategies for both private and public infrastructure development are presented that require no new land purchase while minimizing community noise exposure. New VTOL concepts are introduced with cruise speeds of 200 mph, which yield a greater than three times improvement in overall door-to-door time when compared to current automobiles, and in some cases, improvements of up to 6 times lower trip times.

On-loom, real-time, noncontact detection of fabric defects by ultrasonic imaging.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chien, H. T.

1998-09-08

A noncontact, on-loom ultrasonic inspection technique was developed for real-time 100% defect inspection of fabrics. A prototype was built and tested successfully on loom. The system is compact, rugged, low cost, requires minimal maintenance, is not sensitive to fabric color and vibration, and can easily be adapted to current loom configurations. Moreover, it can detect defects in both the pick and warp directions. The system is capable of determining the size, location, and orientation of each defect. To further improve the system, air-coupled transducers with higher efficiency and sensitivity need to be developed. Advanced detection algorithms also need to bemore » developed for better classification and categorization of defects in real-time.« less

Congestion relief by travel time minimization in near real time : Detroit area I-75 corridor study.

DOT National Transportation Integrated Search

2008-12-01

"This document summarizes the activities concerning the project: Congestion Relief by : Travel Time Minimization in Near Real Time -- Detroit Area I-75 Corridor Study since : the inception of the project (Nov. 22, 2006 through September 30, 2008). : ...

Optimization of radiation treatment of ginger ( Zingiber officinale) rhizomes using response surface methodology

NASA Astrophysics Data System (ADS)

Nketsia-Tabiri, Josephine

1998-06-01

The effects of pre-irradiation storage time (7-21 days), radiation dose (0-75 Gy) and post-irradiation storage time (2-20 weeks) on sprouting, wrinkling and weight loss of ginger was investigated using a central composite rotatable design. Predictive models developed for all three responses were highly significant. Weight loss and wrinkling decreased as pre-irradiation storage time increased. Dose and post-irradiation storage time had significant interactive effects on weight loss and sprouting. Processing conditions for achieving minimal sprouting resulted in maximum weight loss and wrinkling.

Route optimization as an instrument to improve animal welfare and economics in pre-slaughter logistics.

PubMed

Frisk, Mikael; Jonsson, Annie; Sellman, Stefan; Flisberg, Patrik; Rönnqvist, Mikael; Wennergren, Uno

2018-01-01

Each year, more than three million animals are transported from farms to abattoirs in Sweden. Animal transport is related to economic and environmental costs and a negative impact on animal welfare. Time and the number of pick-up stops between farms and abattoirs are two key parameters for animal welfare. Both are highly dependent on efficient and qualitative transportation planning, which may be difficult if done manually. We have examined the benefits of using route optimization in cattle transportation planning. To simulate the effects of various planning time windows and transportation time regulations and number of pick-up stops along each route, we have used data that represent one year of cattle transport. Our optimization model is a development of a model used in forestry transport that solves a general pick-up and delivery vehicle routing problem. The objective is to minimize transportation costs. We have shown that the length of the planning time window has a significant impact on the animal transport time, the total driving time and the total distance driven; these parameters that will not only affect animal welfare but also affect the economy and environment in the pre-slaughter logistic chain. In addition, we have shown that changes in animal transportation regulations, such as minimizing the number of allowed pick-up stops on each route or minimizing animal transportation time, will have positive effects on animal welfare measured in transportation hours and number of pick-up stops. However, this leads to an increase in working time and driven distances, leading to higher transportation costs for the transport and negative environmental impact.

Route optimization as an instrument to improve animal welfare and economics in pre-slaughter logistics

PubMed Central

2018-01-01

Each year, more than three million animals are transported from farms to abattoirs in Sweden. Animal transport is related to economic and environmental costs and a negative impact on animal welfare. Time and the number of pick-up stops between farms and abattoirs are two key parameters for animal welfare. Both are highly dependent on efficient and qualitative transportation planning, which may be difficult if done manually. We have examined the benefits of using route optimization in cattle transportation planning. To simulate the effects of various planning time windows and transportation time regulations and number of pick-up stops along each route, we have used data that represent one year of cattle transport. Our optimization model is a development of a model used in forestry transport that solves a general pick-up and delivery vehicle routing problem. The objective is to minimize transportation costs. We have shown that the length of the planning time window has a significant impact on the animal transport time, the total driving time and the total distance driven; these parameters that will not only affect animal welfare but also affect the economy and environment in the pre-slaughter logistic chain. In addition, we have shown that changes in animal transportation regulations, such as minimizing the number of allowed pick-up stops on each route or minimizing animal transportation time, will have positive effects on animal welfare measured in transportation hours and number of pick-up stops. However, this leads to an increase in working time and driven distances, leading to higher transportation costs for the transport and negative environmental impact. PMID:29513704

Dwell time algorithm based on the optimization theory for magnetorheological finishing

NASA Astrophysics Data System (ADS)

Zhang, Yunfei; Wang, Yang; Wang, Yajun; He, Jianguo; Ji, Fang; Huang, Wen

2010-10-01

Magnetorheological finishing (MRF) is an advanced polishing technique capable of rapidly converging to the required surface figure. This process can deterministically control the amount of the material removed by varying a time to dwell at each particular position on the workpiece surface. The dwell time algorithm is one of the most important key techniques of the MRF. A dwell time algorithm based on the1 matrix equation and optimization theory was presented in this paper. The conventional mathematical model of the dwell time was transferred to a matrix equation containing initial surface error, removal function and dwell time function. The dwell time to be calculated was just the solution to the large, sparse matrix equation. A new mathematical model of the dwell time based on the optimization theory was established, which aims to minimize the 2-norm or ∞-norm of the residual surface error. The solution meets almost all the requirements of precise computer numerical control (CNC) without any need for extra data processing, because this optimization model has taken some polishing condition as the constraints. Practical approaches to finding a minimal least-squares solution and a minimal maximum solution are also discussed in this paper. Simulations have shown that the proposed algorithm is numerically robust and reliable. With this algorithm an experiment has been performed on the MRF machine developed by ourselves. After 4.7 minutes' polishing, the figure error of a flat workpiece with a 50 mm diameter is improved by PV from 0.191λ(λ = 632.8 nm) to 0.087λ and RMS 0.041λ to 0.010λ. This algorithm can be constructed to polish workpieces of all shapes including flats, spheres, aspheres, and prisms, and it is capable of improving the polishing figures dramatically.

Minimizing forced outage risk in generator bidding

NASA Astrophysics Data System (ADS)

Das, Dibyendu

Competition in power markets has exposed the participating companies to physical and financial uncertainties. Generator companies bid to supply power in a day-ahead market. Once their bids are accepted by the ISO they are bound to supply power. A random outage after acceptance of bids forces a generator to buy power from the expensive real-time hourly spot market and sell to the ISO at the set day-ahead market clearing price, incurring losses. A risk management technique is developed to assess this financial risk associated with forced outages of generators and then minimize it. This work presents a risk assessment module which measures the financial risk of generators bidding in an open market for different bidding scenarios. The day-ahead power market auction is modeled using a Unit Commitment algorithm and a combination of Normal and Cauchy distributions generate the real time hourly spot market. Risk profiles are derived and VaRs are calculated at 98 percent confidence level as a measure of financial risk. Risk Profiles and VaRs help the generators to analyze the forced outage risk and different factors affecting it. The VaRs and the estimated total earning for different bidding scenarios are used to develop a risk minimization module. This module will develop a bidding strategy of the generator company such that its estimated total earning is maximized keeping the VaR below a tolerable limit. This general framework of a risk management technique for the generating companies bidding in competitive day-ahead market can also help them in decisions related to building new generators.

[Pharmacokinetic effects of antibiotics on the development of bacterial resistance particularly in reference to azithromycin].

PubMed

Wenisch, C

2000-01-01

Antibiotics reduce the mortality from infectious diseases but not the prevalence of these diseases. Use, and often abuse, of antimicrobial agents encourages the evolution of bacteria toward resistance, often resulting in therapeutic failure. There are two factors which influence potential utility of a drug in a specific clinical situation. The first is the measure of potency of the antibiotic for the pathogen in question (minimal inhibitory concentration [MIC], minimal bactericidal concentration [MBC]). The second is whichever relationship between the concentration-time profile and potency of the antibiotic linked most robustly to clinical outcome (time above MIC or MBC [T > MIC or T > MBC]; Peak/MIC or MBC; area under the curve [AUC]/MIC or AUC/MBC). Herein the effects of pharmacokinetics of antimicrobials on the evolution of antimicrobial resistance with particular reference to azithromycin are considered.

Iodine addition using triiodide solutions

NASA Technical Reports Server (NTRS)

Rutz, Jeffrey A.; Muckle, Susan V.; Sauer, Richard L.

1992-01-01

The study develops: a triiodide solution for use in preparing ground service equipment (GSE) water for Shuttle support, an iodine dissolution method that is reliable and requires minimal time and effort to prepare, and an iodine dissolution agent with a minimal concentration of sodium salt. Sodium iodide and hydriodic acid were both found to dissolve iodine to attain the desired GSE iodine concentrations of 7.5 +/- 2.5 mg/L and 25 +/- 5 mg/L. The 1.75:1 and 2:1 sodium iodide solutions produced higher iodine recoveries than the 1.2:1 hydriodic acid solution. A two-hour preparation time is required for the three sodium iodide solutions. The 1.2:1 hydriodic acid solution can be prepared in less than 5 min. Two sodium iodide stock solutions (2.5:1 and 2:1) were found to dissolve iodine without undergoing precipitation.

Becoming a nurse faculty leader: doing your homework to minimize risk taking.

PubMed

Pearsall, Catherine; Pardue, Karen T; Horton-Deutsch, Sara; Young, Patricia K; Halstead, Judith; Nelson, Kristine A; Morales, Mary Lou; Zungolo, Eileen

2014-01-01

Risk taking is an important aspect of academic leadership; yet, how does taking risks shape leadership development, and what are the practices of risk taking in nurse faculty leaders? This interpretative phenomenological study examines the meaning and experience of risk taking among formal and informal nurse faculty leaders. The theme of doing your homework is generated through in-depth hermeneutic analysis of 14 interview texts and 2 focus group narratives. The practice of doing one's homework is captured in weighing costs and benefits, learning the context, and cultivating relationships. This study develops an evidence base for incorporating ways of doing one's homework into leadership development activities at a time when there is a tremendous need for nurse leaders in academic settings. Examining the practices of doing one's homework to minimize risk as a part of leadership development provides a foundation for cultivating nurse leaders who, in turn, are able to support and build leadership capacity in others. Copyright © 2014 Elsevier Inc. All rights reserved.

Local Risk-Minimization for Defaultable Claims with Recovery Process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biagini, Francesca, E-mail: biagini@mathematik.uni-muenchen.de; Cretarola, Alessandra, E-mail: alessandra.cretarola@dmi.unipg.it

We study the local risk-minimization approach for defaultable claims with random recovery at default time, seen as payment streams on the random interval [0,{tau} Logical-And T], where T denotes the fixed time-horizon. We find the pseudo-locally risk-minimizing strategy in the case when the agent information takes into account the possibility of a default event (local risk-minimization with G-strategies) and we provide an application in the case of a corporate bond. We also discuss the problem of finding a pseudo-locally risk-minimizing strategy if we suppose the agent obtains her information only by observing the non-defaultable assets.

A Fast-Time Simulation Tool for Analysis of Airport Arrival Traffic

NASA Technical Reports Server (NTRS)

Erzberger, Heinz; Meyn, Larry A.; Neuman, Frank

2004-01-01

The basic objective of arrival sequencing in air traffic control automation is to match traffic demand and airport capacity while minimizing delays. The performance of an automated arrival scheduling system, such as the Traffic Management Advisor developed by NASA for the FAA, can be studied by a fast-time simulation that does not involve running expensive and time-consuming real-time simulations. The fast-time simulation models runway configurations, the characteristics of arrival traffic, deviations from predicted arrival times, as well as the arrival sequencing and scheduling algorithm. This report reviews the development of the fast-time simulation method used originally by NASA in the design of the sequencing and scheduling algorithm for the Traffic Management Advisor. The utility of this method of simulation is demonstrated by examining the effect on delays of altering arrival schedules at a hub airport.

V/STOL tilt rotor aircraft study. Volume 1: Conceptual design of useful military and/or commercial aircraft

NASA Technical Reports Server (NTRS)

1972-01-01

The conceptual designs of four useful tilt-rotor aircraft for the 1975 to 1980 time period are presented. Parametric studies leading to design point selection are described, and the characteristics and capabilities of each configuration are presented. An assessment is made of current technology status, and additional tilt-rotor research programs are recommended to minimize the time, cost, and risk of development of these vehicles.

Interval from prostate biopsy to radical prostatectomy does not affect immediate operative outcomes for open or minimally invasive approach.

PubMed

Park, Bumsoo; Choo, Seol Ho; Jeon, Hwang Gyun; Jeong, Byong Chang; Seo, Seong Il; Jeon, Seong Soo; Lee, Hyun Moo; Choi, Han Yong

2014-12-01

Traditionally, urologists recommend an interval of at least 4 weeks after prostate biopsy before radical prostatectomy. The aim of our study was to evaluate whether the interval from prostate biopsy to radical prostatectomy affects immediate operative outcomes, with a focus on differences in surgical approach. The study population of 1,848 radical prostatectomy patients was divided into two groups according to the surgical approach: open or minimally invasive. Open group included perineal and retropubic approach, and minimally invasive group included laparoscopic and robotic approach. The cut-off of the biopsy-to-surgery interval was 4 weeks. Positive surgical margin status, operative time and estimated blood loss were evaluated as endpoint parameters. In the open group, there were significant differences in operative time and estimated blood loss between the <4-week and ≥4-week interval subgroups, but there was no difference in positive margin rate. In the minimally invasive group, there were no differences in the three outcome parameters between the two subgroups. Multivariate analysis revealed that the biopsy-to-surgery interval was not a significant factor affecting immediate operative outcomes in both open and minimally invasive groups, with the exception of the interval ≥4 weeks as a significant factor decreasing operative time in the minimally invasive group. In conclusion, performing open or minimally invasive radical prostatectomy within 4 weeks of prostate biopsy is feasible for both approaches, and is even beneficial for minimally invasive radical prostatectomy to reduce operative time.

Multiobjective optimization model of intersection signal timing considering emissions based on field data: A case study of Beijing.

PubMed

Kou, Weibin; Chen, Xumei; Yu, Lei; Gong, Huibo

2018-04-18

Most existing signal timing models are aimed to minimize the total delay and stops at intersections, without considering environmental factors. This paper analyzes the trade-off between vehicle emissions and traffic efficiencies on the basis of field data. First, considering the different operating modes of cruising, acceleration, deceleration, and idling, field data of emissions and Global Positioning System (GPS) are collected to estimate emission rates for heavy-duty and light-duty vehicles. Second, multiobjective signal timing optimization model is established based on a genetic algorithm to minimize delay, stops, and emissions. Finally, a case study is conducted in Beijing. Nine scenarios are designed considering different weights of emission and traffic efficiency. The results compared with those using Highway Capacity Manual (HCM) 2010 show that signal timing optimized by the model proposed in this paper can decrease vehicles delay and emissions more significantly. The optimization model can be applied in different cities, which provides supports for eco-signal design and development. Vehicle emissions are heavily at signal intersections in urban area. The multiobjective signal timing optimization model is proposed considering the trade-off between vehicle emissions and traffic efficiencies on the basis of field data. The results indicate that signal timing optimized by the model proposed in this paper can decrease vehicle emissions and delays more significantly. The optimization model can be applied in different cities, which provides supports for eco-signal design and development.

Inference regarding multiple structural changes in linear models with endogenous regressors☆

PubMed Central

Hall, Alastair R.; Han, Sanggohn; Boldea, Otilia

2012-01-01

This paper considers the linear model with endogenous regressors and multiple changes in the parameters at unknown times. It is shown that minimization of a Generalized Method of Moments criterion yields inconsistent estimators of the break fractions, but minimization of the Two Stage Least Squares (2SLS) criterion yields consistent estimators of these parameters. We develop a methodology for estimation and inference of the parameters of the model based on 2SLS. The analysis covers the cases where the reduced form is either stable or unstable. The methodology is illustrated via an application to the New Keynesian Phillips Curve for the US. PMID:23805021

Multi-objective group scheduling optimization integrated with preventive maintenance

NASA Astrophysics Data System (ADS)

Liao, Wenzhu; Zhang, Xiufang; Jiang, Min

2017-11-01

This article proposes a single-machine-based integration model to meet the requirements of production scheduling and preventive maintenance in group production. To describe the production for identical/similar and different jobs, this integrated model considers the learning and forgetting effects. Based on machine degradation, the deterioration effect is also considered. Moreover, perfect maintenance and minimal repair are adopted in this integrated model. The multi-objective of minimizing total completion time and maintenance cost is taken to meet the dual requirements of delivery date and cost. Finally, a genetic algorithm is developed to solve this optimization model, and the computation results demonstrate that this integrated model is effective and reliable.

A design for integration.

PubMed

Fenna, D

1977-09-01

For nearly two decades, the development of computerized information systems has struggled for acceptable compromises between the unattainable "total system" and the unacceptable separate applications. Integration of related applications is essential if the computer is to be exploited fully, yet relative simplicity is necessary for systems to be implemented in a reasonable time-scale. This paper discusses a system being progressively developed from minimal beginnings but which, from the outset, had a highly flexible and fully integrated system basis. The system is for batch processing, but can accommodate on-line data input; it is similar in its approach to many transaction-processing real-time systems.

Managing malocclusion in the mixed dentition: six keys to success. Part 1.

PubMed

Fleming, Padhraig S; Johal, Ama; DiBiase, Andrew T

2008-11-01

Indications of developing malocclusion are often present in the mixed dentition.With judicious supervision and timely intervention their effects can be minimized. The general dental practitioner is ideally placed to recognize, manage and correct many such incipient problems. This first of two papers considers three keys to success involving, normal dental development, deviations from normal eruption patterns, crossbite correction and habit cessation. The appropriate management of developing malocclusion may simplify later orthodontic management or indeed make such intervention unnecessary.

Rapid development of Proteomic applications with the AIBench framework.

PubMed

López-Fernández, Hugo; Reboiro-Jato, Miguel; Glez-Peña, Daniel; Méndez Reboredo, José R; Santos, Hugo M; Carreira, Ricardo J; Capelo-Martínez, José L; Fdez-Riverola, Florentino

2011-09-15

In this paper we present two case studies of Proteomics applications development using the AIBench framework, a Java desktop application framework mainly focused in scientific software development. The applications presented in this work are Decision Peptide-Driven, for rapid and accurate protein quantification, and Bacterial Identification, for Tuberculosis biomarker search and diagnosis. Both tools work with mass spectrometry data, specifically with MALDI-TOF spectra, minimizing the time required to process and analyze the experimental data. Copyright 2011 The Author(s). Published by Journal of Integrative Bioinformatics.

Job shop scheduling model for non-identic machine with fixed delivery time to minimize tardiness

NASA Astrophysics Data System (ADS)

Kusuma, K. K.; Maruf, A.

2016-02-01

Scheduling non-identic machines problem with low utilization characteristic and fixed delivery time are frequent in manufacture industry. This paper propose a mathematical model to minimize total tardiness for non-identic machines in job shop environment. This model will be categorized as an integer linier programming model and using branch and bound algorithm as the solver method. We will use fixed delivery time as main constraint and different processing time to process a job. The result of this proposed model shows that the utilization of production machines can be increase with minimal tardiness using fixed delivery time as constraint.

Planetary quarantine

NASA Technical Reports Server (NTRS)

1971-01-01

Developed methodologies and procedures for the reduction of microbial burden on an assembled spacecraft at the time of encapsulation or terminal sterilization are reported. This technology is required for reducing excessive microbial burden on spacecraft components for the purposes of either decreasing planetary contamination probabilities for an orbiter or minimizing the duration of a sterilization process for a lander.

Clementine. Mining new uses for SDI technology

NASA Astrophysics Data System (ADS)

Rustan, Pedro L.

1994-01-01

Using ballistic missile defense technologies for NASA science missions can dramatically reduce program costs and development time. Described is the Clementine spacecraft scheduled for launch to flight-qualify advanced lightweight technologies. The 500-lb spacecraft, which uses lightweight components and minimal redundancy, was built by the Naval Research Laboratory in less than two years.

Exposure to Neighborhood Affluence and Poverty in Childhood and Adolescence and Academic Achievement and Behavior

ERIC Educational Resources Information Center

Anderson, Sara; Leventhal, Tama; Dupéré, Véronique

2014-01-01

Evidence points to associations between the socioeconomic composition of neighborhoods and children's and adolescents' development. A minimal amount of research, however, examines how timing of exposure to neighborhood socioeconomic conditions matters. This study used longitudinal data from the NICHD Study of Early Child Care and Youth Development…

Continued Driving and Time to Transition to Nondriver Status through Error-Specific Driving Restrictions

ERIC Educational Resources Information Center

Freund, Barbara; Petrakos, Davithoula

2008-01-01

We developed driving restrictions that are linked to specific driving errors, allowing cognitively impaired individuals to continue to independently meet mobility needs while minimizing risk to themselves and others. The purpose of this project was to evaluate the efficacy and duration expectancy of these restrictions in promoting safe continued…

40 CFR 60.4333 - What are my general requirements for complying with this subpart?

Code of Federal Regulations, 2011 CFR

2011-07-01

... consistent with good air pollution control practices for minimizing emissions at all times including during startup, shutdown, and malfunction. (b) When an affected unit with heat recovery utilizes a common steam... the other unit(s) utilizing the common heat recovery unit; or (2) Develop, demonstrate, and provide...

40 CFR 60.4333 - What are my general requirements for complying with this subpart?

Code of Federal Regulations, 2010 CFR

2010-07-01

... consistent with good air pollution control practices for minimizing emissions at all times including during startup, shutdown, and malfunction. (b) When an affected unit with heat recovery utilizes a common steam... the other unit(s) utilizing the common heat recovery unit; or (2) Develop, demonstrate, and provide...

Framework for Developing Leadership Skills in Child Care Centres in Queensland, Australia

ERIC Educational Resources Information Center

Nupponen, Hanna

2006-01-01

There has been minimal Australian research focused on leadership and management aspects of directors' work in centre-based child care to date. In Australia, practices in early education have been drawn largely from studies in other cultural contexts, particularly research undertaken in the United States. It is timely that Australian research…

Dogs Don't Need Calculus

ERIC Educational Resources Information Center

Bolt, Mike

2010-01-01

Many optimization problems can be solved without resorting to calculus. This article develops a new variational method for optimization that relies on inequalities. The method is illustrated by four examples, the last of which provides a completely algebraic solution to the problem of minimizing the time it takes a dog to retrieve a thrown ball,…

Introducing and Developing Map Skills with Persons Having Mild or Moderate Learning Difficulties.

ERIC Educational Resources Information Center

Renfrew, Tom

1997-01-01

A British project found that appropriate training in map skills enabled children and adults with mild mental retardation to complete a white color-coded orienteering course with minimal assistance but that persons with moderate mental retardation required more assistance and instruction time to complete course objectives. Describes approaches to…

Preparing Pre-Service Primary School Teachers to Assess Fundamental Motor Skills: Two Skills and Two Approaches

ERIC Educational Resources Information Center

Haynes, John; Miller, Judith

2015-01-01

Background: Pre-service teacher education (PSTE) programmes for generalist primary school teachers have limited time allocated to Physical Education, Health and Personal Development. In practice, teachers in schools are required to assess motor skills despite the fact that their training provides minimal preparation. This necessitates creative…

Fast graph-based relaxed clustering for large data sets using minimal enclosing ball.

PubMed

Qian, Pengjiang; Chung, Fu-Lai; Wang, Shitong; Deng, Zhaohong

2012-06-01

Although graph-based relaxed clustering (GRC) is one of the spectral clustering algorithms with straightforwardness and self-adaptability, it is sensitive to the parameters of the adopted similarity measure and also has high time complexity O(N(3)) which severely weakens its usefulness for large data sets. In order to overcome these shortcomings, after introducing certain constraints for GRC, an enhanced version of GRC [constrained GRC (CGRC)] is proposed to increase the robustness of GRC to the parameters of the adopted similarity measure, and accordingly, a novel algorithm called fast GRC (FGRC) based on CGRC is developed in this paper by using the core-set-based minimal enclosing ball approximation. A distinctive advantage of FGRC is that its asymptotic time complexity is linear with the data set size N. At the same time, FGRC also inherits the straightforwardness and self-adaptability from GRC, making the proposed FGRC a fast and effective clustering algorithm for large data sets. The advantages of FGRC are validated by various benchmarking and real data sets.

Minimized extracorporeal circulation is improving outcome of coronary artery bypass surgery in the elderly.

PubMed

Freundt, Miriam; Ried, Michael; Philipp, Alois; Diez, Claudius; Kolat, Philipp; Hirt, Stephan W; Schmid, Christof; Haneya, Assad

2016-03-01

Advanced age is a known risk factor for morbidity and mortality after coronary artery bypass grafting (CABG). Minimized extracorporeal circulation (MECC) has been shown to reduce the negative effects associated with conventional extracorporeal circulation (CECC). This trial assesses the impact of MECC on the outcome of elderly patients undergoing CABG. Eight hundred and seventy-five patients (mean age 78.35 years) underwent isolated CABG using CECC (n=345) or MECC (n=530). The MECC group had a significantly shorter extracorporeal circulation time (ECCT), cross-clamp time and reperfusion time and lower transfusion needs. Postoperatively, these patients required significantly less inotropic support, fewer blood transfusions, less postoperative hemodialysis and developed less delirium compared to CECC patients. In the MECC group, intensive care unit (ICU) stay was significantly shorter and 30-day mortality was significantly reduced [2.6% versus 7.8%; p<0.001]. In conclusion, MECC improves outcome in elderly patients undergoing CABG surgery. © The Author(s) 2015.

An Interactive Real-time Decision Support System for Leachate Irrigation on Evapotranspiration Landfill Covers

NASA Astrophysics Data System (ADS)

Wang, Y.

2015-12-01

Landfill disposal is still the most common and economical practice for municipal solid waste in most countries. However, heavily polluted leachate generated by excess rainwater percolating through the landfill waste is the major drawback of this practice. Evapotranspiration (ET) cover systems are increasingly being used as alternative cover systems to minimize percolation by evapotranspiration. Leachate recirculation is one of the least expensive options for leachate treatment. The combination of ET cover systems and leachate recirculation can be an economical and environment-friendly practice for landfill leachate management. An interactive real-time decision support system is being developed to better manage leachate irrigation using historical and forecasting weather data, and real time soil moisture data. The main frame of this system includes soil water modules, and plant-soil modules. An inverse simulation module is also included to calibrate certain parameters based on observed data when necessary. It would be an objectives-oriented irrigation management tool to minimize landfill operation costs and negative environmental impacts.

Optical switches for remote and noninvasive control of cell signaling.

PubMed

Gorostiza, Pau; Isacoff, Ehud Y

2008-10-17

Although the identity and interactions of signaling proteins have been studied in great detail, the complexity of signaling networks cannot be fully understood without elucidating the timing and location of activity of individual proteins. To do this, one needs a means for detecting and controlling specific signaling events. An attractive approach is to use light, both to report on and control signaling proteins in cells, because light can probe cells in real time with minimal damage. Although optical detection of signaling events has been successful for some time, the development of the means for optical control has accelerated only recently. Of particular interest is the development of chemically engineered proteins that are directly sensitive to light.

B-ALL minimal residual disease flow cytometry: an application of a novel method for optimization of a single-tube model.

PubMed

Shaver, Aaron C; Greig, Bruce W; Mosse, Claudio A; Seegmiller, Adam C

2015-05-01

Optimizing a clinical flow cytometry panel can be a subjective process dependent on experience. We develop a quantitative method to make this process more rigorous and apply it to B lymphoblastic leukemia/lymphoma (B-ALL) minimal residual disease (MRD) testing. We retrospectively analyzed our existing three-tube, seven-color B-ALL MRD panel and used our novel method to develop an optimized one-tube, eight-color panel, which was tested prospectively. The optimized one-tube, eight-color panel resulted in greater efficiency of time and resources with no loss in diagnostic power. Constructing a flow cytometry panel using a rigorous, objective, quantitative method permits optimization and avoids problems of interdependence and redundancy in a large, multiantigen panel. Copyright© by the American Society for Clinical Pathology.

Food processing by high hydrostatic pressure.

PubMed

Yamamoto, Kazutaka

2017-04-01

High hydrostatic pressure (HHP) process, as a nonthermal process, can be used to inactivate microbes while minimizing chemical reactions in food. In this regard, a HHP level of 100 MPa (986.9 atm/1019.7 kgf/cm 2 ) and more is applied to food. Conventional thermal process damages food components relating color, flavor, and nutrition via enhanced chemical reactions. However, HHP process minimizes the damages and inactivates microbes toward processing high quality safe foods. The first commercial HHP-processed foods were launched in 1990 as fruit products such as jams, and then some other products have been commercialized: retort rice products (enhanced water impregnation), cooked hams and sausages (shelf life extension), soy sauce with minimized salt (short-time fermentation owing to enhanced enzymatic reactions), and beverages (shelf life extension). The characteristics of HHP food processing are reviewed from viewpoints of nonthermal process, history, research and development, physical and biochemical changes, and processing equipment.

Using generalizability theory to develop clinical assessment protocols.

PubMed

Preuss, Richard A

2013-04-01

Clinical assessment protocols must produce data that are reliable, with a clinically attainable minimal detectable change (MDC). In a reliability study, generalizability theory has 2 advantages over classical test theory. These advantages provide information that allows assessment protocols to be adjusted to match individual patient profiles. First, generalizability theory allows the user to simultaneously consider multiple sources of measurement error variance (facets). Second, it allows the user to generalize the findings of the main study across the different study facets and to recalculate the reliability and MDC based on different combinations of facet conditions. In doing so, clinical assessment protocols can be chosen based on minimizing the number of measures that must be taken to achieve a realistic MDC, using repeated measures to minimize the MDC, or simply based on the combination that best allows the clinician to monitor an individual patient's progress over a specified period of time.

Time versus energy minimization migration strategy varies with body size and season in long-distance migratory shorebirds.

PubMed

Zhao, Meijuan; Christie, Maureen; Coleman, Jonathan; Hassell, Chris; Gosbell, Ken; Lisovski, Simeon; Minton, Clive; Klaassen, Marcel

2017-01-01

Migrants have been hypothesised to use different migration strategies between seasons: a time-minimization strategy during their pre-breeding migration towards the breeding grounds and an energy-minimization strategy during their post-breeding migration towards the wintering grounds. Besides season, we propose body size as a key factor in shaping migratory behaviour. Specifically, given that body size is expected to correlate negatively with maximum migration speed and that large birds tend to use more time to complete their annual life-history events (such as moult, breeding and migration), we hypothesise that large-sized species are time stressed all year round. Consequently, large birds are not only likely to adopt a time-minimization strategy during pre-breeding migration, but also during post-breeding migration, to guarantee a timely arrival at both the non-breeding (i.e. wintering) and breeding grounds. We tested this idea using individual tracks across six long-distance migratory shorebird species (family Scolopacidae) along the East Asian-Australasian Flyway varying in size from 50 g to 750 g lean body mass. Migration performance was compared between pre- and post-breeding migration using four quantifiable migratory behaviours that serve to distinguish between a time- and energy-minimization strategy, including migration speed, number of staging sites, total migration distance and step length from one site to the next. During pre- and post-breeding migration, the shorebirds generally covered similar distances, but they tended to migrate faster, used fewer staging sites, and tended to use longer step lengths during pre-breeding migration. These seasonal differences are consistent with the prediction that a time-minimization strategy is used during pre-breeding migration, whereas an energy-minimization strategy is used during post-breeding migration. However, there was also a tendency for the seasonal difference in migration speed to progressively disappear with an increase in body size, supporting our hypothesis that larger species tend to use time-minimization strategies during both pre- and post-breeding migration. Our study highlights that body size plays an important role in shaping migratory behaviour. Larger migratory bird species are potentially time constrained during not only the pre- but also the post-breeding migration. Conservation of their habitats during both seasons may thus be crucial for averting further population declines.

System analysis for technology transfer readiness assessment of horticultural postharvest

NASA Astrophysics Data System (ADS)

Hayuningtyas, M.; Djatna, T.

2018-04-01

Availability of postharvest technology is becoming abundant, but only a few technologies are applicable and useful to a wider community purposes. Based on this problem it requires a significant readiness level of transfer technology approach. This system is reliable to access readiness a technology with level, from 1-9 and to minimize time of transfer technology in every level, time required technology from the selection process can be minimum. Problem was solved by using Relief method to determine ranking by weighting feasible criteria on postharvest technology in each level and PERT (Program Evaluation Review Technique) to schedule. The results from ranking process of post-harvest technology in the field of horticulture is able to pass level 7. That, technology can be developed to increase into pilot scale and minimize time required for technological readiness on PERT with optimistic time of 7,9 years. Readiness level 9 shows that technology has been tested on the actual conditions also tied with estimated production price compared to competitors. This system can be used to determine readiness of technology innovation that is derived from agricultural raw materials and passes certain stages.

Graviresponsiveness and the Development of Columella Tissue in Primary and Lateral Roots of Ricinus communis1

PubMed Central

Moore, Randy; Pasieniuk, John

1984-01-01

Half-tipped primary and lateral roots of Ricinus communis cv Hale bend toward the side of the root on which the intact half-tip remains. Therefore, the minimal graviresponsiveness of lateral roots is not due to the inability of their caps to produce growth effectors (presumably inhibitors). The columella tissues of primary (i.e. graviresponsive) roots are (a) 4.30 times longer, (b) 2.95 times wider, (c) 37.4 times more voluminous, and (d) composed of 17.2 times more cells than those of lateral roots. The onset of positive gravitropism by lateral roots is positively correlated with a (a) 2.99-fold increase in length, (b) 2.63-fold increase in width, and (c) 20.7-fold increase in volume of their columella tissues. We propose that the minimal graviresponsiveness of lateral roots is due to the small size of their columella tissues, which results in their caps being unable to (a) establish a concentration gradient of the effector sufficient to induce gravicurvature and (b) produce as much of the effector as caps of graviresponsive roots. Images Fig. 1 PMID:11540818

Structural Optimization for Reliability Using Nonlinear Goal Programming

NASA Technical Reports Server (NTRS)

El-Sayed, Mohamed E.

1999-01-01

This report details the development of a reliability based multi-objective design tool for solving structural optimization problems. Based on two different optimization techniques, namely sequential unconstrained minimization and nonlinear goal programming, the developed design method has the capability to take into account the effects of variability on the proposed design through a user specified reliability design criterion. In its sequential unconstrained minimization mode, the developed design tool uses a composite objective function, in conjunction with weight ordered design objectives, in order to take into account conflicting and multiple design criteria. Multiple design criteria of interest including structural weight, load induced stress and deflection, and mechanical reliability. The nonlinear goal programming mode, on the other hand, provides for a design method that eliminates the difficulty of having to define an objective function and constraints, while at the same time has the capability of handling rank ordered design objectives or goals. For simulation purposes the design of a pressure vessel cover plate was undertaken as a test bed for the newly developed design tool. The formulation of this structural optimization problem into sequential unconstrained minimization and goal programming form is presented. The resulting optimization problem was solved using: (i) the linear extended interior penalty function method algorithm; and (ii) Powell's conjugate directions method. Both single and multi-objective numerical test cases are included demonstrating the design tool's capabilities as it applies to this design problem.

Comparison between qualitative and real-time polymerase chain reaction to evaluate minimal residual disease in children with acute lymphoblastic leukemia.

PubMed

Paula, Francisco Danilo Ferreira; Elói-Santos, Silvana Maria; Xavier, Sandra Guerra; Ganazza, Mônica Aparecida; Jotta, Patricia Yoshioka; Yunes, José Andrés; Viana, Marcos Borato; Assumpção, Juliana Godoy

2015-01-01

Minimal residual disease is an important independent prognostic factor that can identify poor responders among patients with acute lymphoblastic leukemia. The aim of this study was to analyze minimal residual disease using immunoglobulin (Ig) and T-cell receptor (TCR) gene rearrangements by conventional polymerase chain reaction followed by homo-heteroduplex analysis and to compare this with real-time polymerase chain reaction at the end of the induction period in children with acute lymphoblastic leukemia. Seventy-four patients diagnosed with acute lymphoblastic leukemia were enrolled. Minimal residual disease was evaluated by qualitative polymerase chain reaction in 57 and by both tests in 44. The Kaplan-Meier and multivariate Cox methods and the log-rank test were used for statistical analysis. Nine patients (15.8%) were positive for minimal residual disease by qualitative polymerase chain reaction and 11 (25%) by real-time polymerase chain reaction considering a cut-off point of 1×10(-3) for precursor B-cell acute lymphoblastic leukemia and 1×10(-2) for T-cell acute lymphoblastic leukemia. Using the qualitative method, the 3.5-year leukemia-free survival was significantly higher in children negative for minimal residual disease compared to those with positive results (84.1%±5.6% versus 41.7%±17.3%, respectively; p-value=0.004). There was no significant association between leukemia-free survival and minimal residual disease by real-time polymerase chain reaction. Minimal residual disease by qualitative polymerase chain reaction was the only variable significantly correlated to leukemia-free survival. Given the difficulties in the implementation of minimal residual disease monitoring by real-time polymerase chain reaction in most treatment centers in Brazil, the qualitative polymerase chain reaction strategy may be a cost-effective alternative. Copyright © 2015 Associação Brasileira de Hematologia, Hemoterapia e Terapia Celular. Published by Elsevier Editora Ltda. All rights reserved.

Auto Design

NASA Technical Reports Server (NTRS)

1988-01-01

The 1987 Honda Acura Legend Coupe was designed with aid of the NASA-developed NASTRAN computer program. NASTRAN takes an electronic look at a computerized design and predicts how the structure will react under a great many different conditions. Quick and inexpensive, it minimizes trial and error in the design process and makes possible better, lighter, safer structures while affording significant savings in development time. All Honda auto products designed in the 1980's have been analyzed by the NASTRAN program.

MIS Score: Prediction Model for Minimally Invasive Surgery.

PubMed

Hu, Yuanyuan; Cao, Jingwei; Hou, Xianzeng; Liu, Guangcun

2017-03-01

Reports suggest that patients with spontaneous intracerebral hemorrhage (ICH) can benefit from minimally invasive surgery, but the inclusion criterion for operation is controversial. This article analyzes factors affecting the 30-day prognoses of patients who have received minimally invasive surgery and proposes a simple grading scale that represents clinical operation effectiveness. The records of 101 patients with spontaneous ICH presenting to Qianfoshan Hospital were reviewed. Factors affecting their 30-day prognosis were identified by logistic regression. A clinical grading scale, the MIS score, was developed by weighting the independent predictors based on these factors. Univariate analysis revealed that the factors that affect 30-day prognosis include Glasgow coma scale score (P < 0.01), age ≥80 years (P < 0.05), blood glucose (P < 0.01), ICH volume (P < 0.01), operation time (P < 0.05), and presence of intraventricular hemorrhage (P < 0.001). Logistic regression revealed that the factors that affect 30-day prognosis include Glasgow coma scale score (P < 0.05), age (P < 0.05), ICH volume (P < 0.01), and presence of intraventricular hemorrhage (P < 0.05). The MIS score was developed accordingly; 39 patients with 0-1 MIS scores had favorable prognoses, whereas only 9 patients with 2-5 MIS scores had poor prognoses. The MIS score is a simple grading scale that can be used to select patients who are suited for minimal invasive drainage surgery. When MIS score is 0-1, minimal invasive surgery is strongly recommended for patients with spontaneous cerebral hemorrhage. The scale merits further prospective studies to fully determine its efficacy. Copyright © 2016 Elsevier Inc. All rights reserved.

Initial Results from the Miniature Imager for Neutral Ionospheric Atoms and Magnetospheric Electrons (MINI-ME) on the FASTSAT Spacecraft

NASA Technical Reports Server (NTRS)

Collier, Michael R.; Rowland, Douglas; Keller, John W.; Chornay, Dennis; Khazanov, George; Herrero, Federico; Moore, Thomas E.; Kujawski, Joseph; Casas, Joseph C.; Wilson, Gordon

2011-01-01

The MINI-ME instrument is a collaborative effort between NASA's Goddard Space Flight Center (GSFC) and the U.S. Naval Academy, funded solely through GSFC Internal Research and Development (IRAD) awards. It detects neutral atoms from about 10 eV to about 700 eV (in 30 energy steps) in its current operating configuration with an approximately 10 degree by 360 degree field-of-view, divided into six sectors. The instrument was delivered on August 3, 2009 to Marshall Space Flight Center (MSFC) for integration with the FASTSAT-HSV01 small spacecraft bus developed by MSFC and a commercial partner, one of six Space Experiment Review Board (SERB) experiments on FASTSAT and one of three GSFC instruments (PISA and TTI being the other two). The FASTSAT spacecraft was launched on November 21, 2010 from Kodiak, Alaska on a Minotaur IV as a secondary payload and inserted into a 650 km, 72 degree inclination orbit, very nearly circular. MINI-ME has been collecting science data, as spacecraft resources would permit, in "optimal science mode" since January 20, 2011. In this presentation, we report initial science results including the potential first observations of neutral molecular ionospheric outflow. At the time of this abstract, we have identified 15 possible molecular outflow events. All these events occur between about 65 and 82 degrees geomagnetic latitude and most map to the auroral oval. The MINI-ME results provide an excellent framework for interpretation of the MILENA data, two instruments almost identical to MINI-ME that will launch on the VISIONS suborbital mission

Initial Results from the Miniature Imager for Neutral Ionospheric atoms and Magnetospheric Electrons (MINI-ME) on the FASTSAT Spacecraft

NASA Astrophysics Data System (ADS)

Collier, M. R.; Rowland, D. E.; Keller, J. W.; Chornay, D. J.; Khazanov, G. V.; Herrero, F.; Moore, T. E.; Kujawski, J. T.; Casas, J. C.; Wilson, G. R.

2011-12-01

The MINI-ME instrument is a collaborative effort between NASA's Goddard Space Flight Center (GSFC) and the U.S. Naval Academy, funded solely through GSFC Internal Research and Development (IRAD) awards. It detects neutral atoms from about 10 eV to about 700 eV (in 30 energy steps) in its current operating configuration with an approximately 10 degree by 360 degree field-of-view, divided into six sectors. The instrument was delivered on August 3, 2009 to Marshall Space Flight Center (MSFC) for integration with the FASTSAT-HSV01 small spacecraft bus developed by MSFC and a commercial partner, one of six Space Experiments Review Board (SERB) experiments on FASTSAT and one of three GSFC instruments (PISA and TTI being the other two). The FASTSAT spacecraft was launched on November 21, 2010 from Kodiak, Alaska on a Minotaur IV as a secondary payload and inserted into a 650 km, 72 degree inclination orbit, very nearly circular. MINI-ME has been collecting science data, as spacecraft resources would permit, in "optimal science mode" since January 20, 2011. In this presentation, we report initial science results including the potential first observations of neutral molecular ionospheric outflow. At the time of this abstract, we have identified 15 possible molecular outflow events. All these events occur between about 65 and 82 degrees geomagnetic latitude and most map to the auroral oval. The MINI-ME results provide an excellent framework for interpretation of the MILENA data, two instruments almost identical to MINI-ME that will launch on the VISIONS suborbital mission (PI: Douglas Rowland).

Framing matters: Effects of framing on older adults’ exploratory decision-making

PubMed Central

Cooper, Jessica A.; Blanco, Nathaniel; Maddox, W. Todd

2016-01-01

We examined framing effects on exploratory decision-making. In Experiment 1 we tested older and younger adults in two decision-making tasks separated by one week, finding that older adults’ decision-making performance was preserved when maximizing gains, but declined when minimizing losses. Computational modeling indicates that younger adults in both conditions, and older adults in gains-maximization, utilized a decreasing threshold strategy (which is optimal), but older adults in losses were better fit by a fixed-probability model of exploration. In Experiment 2 we examined within-subjects behavior in older and younger adults in the same exploratory decision-making task, but without a time separation between tasks. We replicated the older adult disadvantage in loss-minimization from Experiment 1, and found that the older adult deficit was significantly reduced when the loss-minimization task immediately followed the gains-maximization task. We conclude that older adults’ performance in exploratory decision-making is hindered when framed as loss-minimization, but that this deficit is attenuated when older adults can first develop a strategy in a gains-framed task. PMID:27977218

Minimally invasive paediatric cardiac surgery.

PubMed

Bacha, Emile; Kalfa, David

2014-01-01

The concept of minimally invasive surgery for congenital heart disease in paediatric patients is broad, and has the aim of reducing the trauma of the operation at each stage of management. Firstly, in the operating room using minimally invasive incisions, video-assisted thoracoscopic and robotically assisted surgery, hybrid procedures, image-guided intracardiac surgery, and minimally invasive cardiopulmonary bypass strategies. Secondly, in the intensive-care unit with neuroprotection and 'fast-tracking' strategies that involve early extubation, early hospital discharge, and less exposure to transfused blood products. Thirdly, during postoperative mid-term and long-term follow-up by providing the children and their families with adequate support after hospital discharge. Improvement of these strategies relies on the development of new devices, real-time multimodality imaging, aids to instrument navigation, miniaturized and specialized instrumentation, robotic technology, and computer-assisted modelling of flow dynamics and tissue mechanics. In addition, dedicated multidisciplinary co-ordinated teams involving congenital cardiac surgeons, perfusionists, intensivists, anaesthesiologists, cardiologists, nurses, psychologists, and counsellors are needed before, during, and after surgery to go beyond apparent technological and medical limitations with the goal to 'treat more while hurting less'.

Framing matters: Effects of framing on older adults' exploratory decision-making.

PubMed

Cooper, Jessica A; Blanco, Nathaniel J; Maddox, W Todd

2017-02-01

We examined framing effects on exploratory decision-making. In Experiment 1 we tested older and younger adults in two decision-making tasks separated by one week, finding that older adults' decision-making performance was preserved when maximizing gains, but it declined when minimizing losses. Computational modeling indicates that younger adults in both conditions, and older adults in gains maximization, utilized a decreasing threshold strategy (which is optimal), but older adults in losses were better fit by a fixed-probability model of exploration. In Experiment 2 we examined within-subject behavior in older and younger adults in the same exploratory decision-making task, but without a time separation between tasks. We replicated the older adult disadvantage in loss minimization from Experiment 1 and found that the older adult deficit was significantly reduced when the loss-minimization task immediately followed the gains-maximization task. We conclude that older adults' performance in exploratory decision-making is hindered when framed as loss minimization, but that this deficit is attenuated when older adults can first develop a strategy in a gains-framed task. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Use of High Resolution 3D Diffusion Tensor Imaging to Study Brain White Matter Development in Live Neonatal Rats

PubMed Central

Cai, Yu; McMurray, Matthew S.; Oguz, Ipek; Yuan, Hong; Styner, Martin A.; Lin, Weili; Johns, Josephine M.; An, Hongyu

2011-01-01

High resolution diffusion tensor imaging (DTI) can provide important information on brain development, yet it is challenging in live neonatal rats due to the small size of neonatal brain and motion-sensitive nature of DTI. Imaging in live neonatal rats has clear advantages over fixed brain scans, as longitudinal and functional studies would be feasible to understand neuro-developmental abnormalities. In this study, we developed imaging strategies that can be used to obtain high resolution 3D DTI images in live neonatal rats at postnatal day 5 (PND5) and PND14, using only 3 h of imaging acquisition time. An optimized 3D DTI pulse sequence and appropriate animal setup to minimize physiological motion artifacts are the keys to successful high resolution 3D DTI imaging. Thus, a 3D rapid acquisition relaxation enhancement DTI sequence with twin navigator echoes was implemented to accelerate imaging acquisition time and minimize motion artifacts. It has been suggested that neonatal mammals possess a unique ability to tolerate mild-to-moderate hypothermia and hypoxia without long term impact. Thus, we additionally utilized this ability to minimize motion artifacts in magnetic resonance images by carefully suppressing the respiratory rate to around 15/min for PND5 and 30/min for PND14 using mild-to-moderate hypothermia. These imaging strategies have been successfully implemented to study how the effect of cocaine exposure in dams might affect brain development in their rat pups. Image quality resulting from this in vivo DTI study was comparable to ex vivo scans. fractional anisotropy values were also similar between the live and fixed brain scans. The capability of acquiring high quality in vivo DTI imaging offers a valuable opportunity to study many neurological disorders in brain development in an authentic living environment. PMID:22013426

Adapted shared reading at school for minimally verbal students with autism.

PubMed

Mucchetti, Charlotte A

2013-05-01

Almost nothing is known about the capacity of minimally verbal students with autism to develop literacy skills. Shared reading is a regular practice in early education settings and is widely thought to encourage language and literacy development. There is some evidence that children with severe disabilities can be engaged in adapted shared reading activities. The current study examines the impact of teacher-led adapted shared reading activities on engagement and story comprehension in minimally verbal 5-6-year-old children with autism using a multiple baseline/alternating treatment design. Four students and three teachers participated. Teachers conducted adapted shared reading activities with modified books (visual supports, three-dimensional objects, simplified text) and used specific strategies for increasing student engagement. Student performance during adapted activities was compared to performance during standard shared reading sessions. All four students showed increased story comprehension and engagement during adapted shared reading. Average percentage of session engaged was 87%-100% during adapted sessions, compared with 41%-52% during baseline. Average number of correct responses to story comprehension questions was 4.2-4.8 out of 6 during adapted sessions compared with 1.2-2 during baseline. Visual supports, tactile objects, and specific teaching strategies offer ways for minimally verbal students to meaningfully participate in literacy activities. Future research should investigate adapted shared reading activities implemented classroom-wide as well as joint engagement, language, and literacy outcomes after using such activities over time.

MR imaging guidance for minimally invasive procedures

NASA Astrophysics Data System (ADS)

Wong, Terence Z.; Kettenbach, Joachim; Silverman, Stuart G.; Schwartz, Richard B.; Morrison, Paul R.; Kacher, Daniel F.; Jolesz, Ferenc A.

1998-04-01

Image guidance is one of the major challenges common to all minimally invasive procedures including biopsy, thermal ablation, endoscopy, and laparoscopy. This is essential for (1) identifying the target lesion, (2) planning the minimally invasive approach, and (3) monitoring the therapy as it progresses. MRI is an ideal imaging modality for this purpose, providing high soft tissue contrast and multiplanar imaging, capability with no ionizing radiation. An interventional/surgical MRI suite has been developed at Brigham and Women's Hospital which provides multiplanar imaging guidance during surgery, biopsy, and thermal ablation procedures. The 0.5T MRI system (General Electric Signa SP) features open vertical access, allowing intraoperative imaging to be performed. An integrated navigational system permits near real-time control of imaging planes, and provides interactive guidance for positioning various diagnostic and therapeutic probes. MR imaging can also be used to monitor cryotherapy as well as high temperature thermal ablation procedures sing RF, laser, microwave, or focused ultrasound. Design features of the interventional MRI system will be discussed, and techniques will be described for interactive image acquisition and tracking of interventional instruments. Applications for interactive and near-real-time imaging will be presented as well as examples of specific procedures performed using MRI guidance.

Update on laparoscopic, robotic, and minimally invasive vaginal surgery for pelvic floor repair.

PubMed

Ross, J W; Preston, M R

2009-06-01

Advanced laparoscopic surgery marked the beginning of minimally invasive pelvic surgery. This technique lead to the development of laparoscopic hysterectomy, colposuspension, paravaginal repair, uterosacral suspension, and sacrocolpopexy without an abdominal incision. With laparoscopy there is a significant decrease in postoperative pain, shorter length of hospital stay, and a faster return to normal activities. These advantages made laparoscopy very appealing to patients. Advanced laparoscopy requires a special set of surgical skills and in the early phase of development training was not readily available. Advanced laparoscopy was developed by practicing physicians, instead of coming down through the more usual academic channels. The need for special training did hinder widespread acceptance. Nonetheless by physician to physician training and society training courses it has continued to grow and now has been incorporated in most medical school curriculums. In the last few years there has been new interest in laparoscopy because of the development of robotic assistance. The 3D vision and 720 degree articulating arms with robotics have made suture intensive procedures much easier. Laparosco-pic robotic-assisted sacrocolpopexy is in the reach of most surgeons. This field is so new that there is very little data to evaluate at this time. There are short comings with laparoscopy and even with robotic-assisted procedures it is not the cure all for pelvic floor surgery. Laparoscopic procedures are long and many patients requiring pelvic floor surgery have medical conditions preventing long anesthesia. Minimally invasive vaginal surgery has developed from the concept of tissue replacement by synthetic mesh. Initially sheets of synthetic mesh were tailored by physicians to repair the anterior and posterior vaginal compartment. The use of mesh by general surgeons for hernia repair has served as a model for urogynecology. There have been rapid improvements in biomaterials and specialized kits have been developed by industry. The purpose of this article is to present an update in urogynecologic laparoscopy, robotic surgery, and minimally invasive vaginal surgery.

Private practice outcomes: validated outcomes data collection in private practice.

PubMed

Goldstein, Jack

2010-10-01

Improved patient care is related to validated outcome measures requiring the collection of three distinct data types: (1) demographics; (2) patient outcome measures; and (3) physician treatment. Previous impediments to widespread data collection have been: cost, office disruption, personnel requirements, physician motivation, data integration, and security. There are currently few means to collect data to be used for collaborative analysis. We therefore developed an inexpensive, patient-centric mechanism to reduce redundant data entry, limiting cost and personnel requirements. Using an intuitive touch-screen kiosk interface program, all data elements have been captured in a private practice setting since 2000. Developed for small to medium sized offices, this is scalable to larger organizations. Questionnaire navigation is patient driven, with demographics shared with EMR and billing systems. Integration of billing and EMR with outcomes minimizes cost and personnel time. Data are deidentified locally and may be centrally shared. Since data are entered by the patients, minimal personnel costs are incurred. Physician disincentives are minimized with cost reduction, time savings and ease of use. To date, we have collected high level data on most total joint patients, with excellent patient compliance. By addressing impediments to broad application, we may enable widespread local data collection in all practice settings. Data may be shared centrally, allowing comparative effectiveness research to become a reality. Future success will require broad physician participation, uniformity of data collected, and designation of a central site for receipt of data and its collaborative comparative analysis.

Scheduling time-critical graphics on multiple processors

NASA Technical Reports Server (NTRS)

Meyer, Tom W.; Hughes, John F.

1995-01-01

This paper describes an algorithm for the scheduling of time-critical rendering and computation tasks on single- and multiple-processor architectures, with minimal pipelining. It was developed to manage scientific visualization scenes consisting of hundreds of objects, each of which can be computed and displayed at thousands of possible resolution levels. The algorithm generates the time-critical schedule using progressive-refinement techniques; it always returns a feasible schedule and, when allowed to run to completion, produces a near-optimal schedule which takes advantage of almost the entire multiple-processor system.

Fluorescence-based enhanced reality (FLER) for real-time estimation of bowel perfusion in minimally invasive surgery

NASA Astrophysics Data System (ADS)

Diana, Michele

2016-03-01

Pre-anastomotic bowel perfusion is a key factor for a successful healing process. Clinical judgment has limited accuracy to evaluate intestinal microperfusion. Fluorescence videography is a promising tool for image-guided intraoperative assessment of the bowel perfusion at the future anastomotic site in the setting of minimally invasive procedures. The standard configuration for fluorescence videography includes a Near-Infrared endoscope able to detect the signal emitted by a fluorescent dye, more frequently Indocyanine Green (ICG), which is administered by intravenous injection. Fluorescence intensity is proportional to the amount of fluorescent dye diffusing in the tissue and consequently is a surrogate marker of tissue perfusion. However, fluorescence intensity alone remains a subjective approach and an integrated computer-based analysis of the over-time evolution of the fluorescence signal is required to obtain quantitative data. We have developed a solution integrating computer-based analysis for intra-operative evaluation of the optimal resection site, based on the bowel perfusion as determined by the dynamic fluorescence intensity. The software can generate a "virtual perfusion cartography", based on the "fluorescence time-to-peak". The virtual perfusion cartography can be overlapped onto real-time laparoscopic images to obtain the Enhanced Reality effect. We have defined this approach FLuorescence-based Enhanced Reality (FLER). This manuscript describes the stepwise development of the FLER concept.

Effective time management: surgery, research, service, travel, fitness, and family.

PubMed

Porta, C Rees; Anderson, Michael R; Steele, Scott R

2013-12-01

Over 1,500 years ago, the St. Benedictine Monks used planning and strict schedules to increase their productivity. Since then, surgeons have developed several different strategies to manage our time effectively. Finding a balance among career, family, and hobbies is essential for maintaining satisfaction and optimizing productivity. Several recurring themes throughout the medical literature offer potential solutions to help maximize the little time surgeons possess. In this article, we will explore some of the methods and strategies available to help surgeons minimize waste and make the most of the most precious commodity we have-our time.

Effective Time Management: Surgery, Research, Service, Travel, Fitness, and Family

PubMed Central

Porta, C. Rees; Anderson, Michael R.; Steele, Scott R.

2013-01-01

Over 1,500 years ago, the St. Benedictine Monks used planning and strict schedules to increase their productivity. Since then, surgeons have developed several different strategies to manage our time effectively. Finding a balance among career, family, and hobbies is essential for maintaining satisfaction and optimizing productivity. Several recurring themes throughout the medical literature offer potential solutions to help maximize the little time surgeons possess. In this article, we will explore some of the methods and strategies available to help surgeons minimize waste and make the most of the most precious commodity we have—our time. PMID:24436684

A UNIX-based real-time data acquisition system for microprobe analysis using an advanced X11 window toolkit

NASA Astrophysics Data System (ADS)

Kramer, J. L. A. M.; Ullings, A. H.; Vis, R. D.

1993-05-01

A real-time data acquisition system for microprobe analysis has been developed at the Free University of Amsterdam. The system is composed of two parts: a front-end real-time and a back-end monitoring system. The front-end consists of a VMEbus based system which reads out a CAMAC crate. The back-end is implemented on a Sun work station running the UNIX operating system. This separation allows the integration of a minimal, and consequently very fast, real-time executive within the sophisticated possibilities of advanced UNIX work stations.

Minimum entropy density method for the time series analysis

NASA Astrophysics Data System (ADS)

Lee, Jeong Won; Park, Joongwoo Brian; Jo, Hang-Hyun; Yang, Jae-Suk; Moon, Hie-Tae

2009-01-01

The entropy density is an intuitive and powerful concept to study the complicated nonlinear processes derived from physical systems. We develop the minimum entropy density method (MEDM) to detect the structure scale of a given time series, which is defined as the scale in which the uncertainty is minimized, hence the pattern is revealed most. The MEDM is applied to the financial time series of Standard and Poor’s 500 index from February 1983 to April 2006. Then the temporal behavior of structure scale is obtained and analyzed in relation to the information delivery time and efficient market hypothesis.

Minimally invasive plating osteosynthesis for mid-distal third humeral shaft fractures.

PubMed

Lian, Kejian; Wang, Lei; Lin, Dasheng; Chen, Zhiwen

2013-08-01

Mid-distal third humeral shaft fractures can be effectively treated with minimally invasive plating osteosynthesis and intramedullary nailing (IMN). However, these 2 treatments have not been adequately compared. Forty-seven patients (47 fractures) with mid-distal third humeral shaft fractures were randomly allocated to undergo either minimally invasive plating osteosynthesis (n=24) or IMN (n=23). The 2 groups were similar in terms of fracture patterns, fracture location, age, and associated injuries. Intraoperative measurements included blood loss and operative time. Clinical outcome measurements included fracture healing, radial nerve recovery, and elbow and shoulder discomfort. Radiographic measurements included fracture alignment, time to healing, delayed union, and nonunion. Functional outcome was satisfactory in both groups. Mean American Shoulder and Elbow Surgeons score and Mayo score were both better for the minimally invasive plating osteosynthesis group than for the IMN group (98.2 vs 97.6, respectively, and 93.5 vs 94.1, respectively; P<.001). Operative time was shorter and less intraoperative blood loss occurred in the minimally invasive plating osteosynthesis group than in the IMN group. Average time to union was similar in both groups. Primary union was achieved in 23 of 24 patients in the minimally invasive plating osteosynthesis group and in 22 of 23 in the IMN group. Minimally invasive plating osteosynthesis may have outcomes comparable with IMN for the management of mid-distal third humeral shaft fractures. Minimally invasive plating osteosynthesis is more suitable for complex fractures, especially for radial protection and motion recovery of adjacent joints, compared with IMN for simple fractures. Copyright 2013, SLACK Incorporated.

Tissue modification with feedback: the smart scalpel

NASA Astrophysics Data System (ADS)

Sebern, Elizabeth L.; Brenan, Colin J. H.; Anderson, R. Rox; Hunter, Ian W.

1998-10-01

While feedback control is widespread throughout many engineering fields, there are almost no examples of surgical instruments that utilize a real-time detection and intervention strategy. This concept of closed loop feedback can be applied to the development of autonomous or semi- autonomous minimally invasive robotic surgical systems for efficient excision or modification of diseased tissue. Spatially localized regions of the tissue are first probed to distinguish pathological from healthy tissue based on differences in histochemical and morphological properties. Energy is directed to only the diseased tissue, minimizing collateral damage by leaving the adjacent healthy tissue intact. Continuous monitoring determines treatment effectiveness and, if needed, enables real-time treatment modifications to produce optimal therapeutic outcomes. The present embodiment of this general concept is a microsurgical instrument we call the Smart Scalpel, designed to treat skin angiodysplasias such as port wine stains. Other potential Smart Scalpel applications include psoriasis treatment and early skin cancer detection and intervention.

Battery and capacitor technology for uniform charge time in implantable cardioverter-defibrillators

NASA Astrophysics Data System (ADS)

Skarstad, Paul M.

Implantable cardioverter-defibrillators (ICDs) are implantable medical devices designed to treat ventricular fibrillation by administering a high-voltage shock directly to the heart. Minimizing the time a patient remains in fibrillation is an important goal of this therapy. Both batteries and high-voltage capacitors used in these devices can display time-dependency in performance, resulting in significant extension of charge time. Altering the electrode balance in lithium/silver vanadium oxide batteries used to power these devices has minimized time-dependent changes in battery resistance. Charge-interval dependent changes in capacitor cycling efficiency have been minimized for stacked-plate aluminum electrolytic capacitors by a combination of material and processing factors.

Minimization of lumen depreciation in LED lamps using thermal transient behavior analysis and design optimizations.

PubMed

Khan, M Nisa

2016-02-10

We expansively investigate thermal behaviors of various general-purpose light-emitting diode (LED) lamps and apply our measured results, validated by simulation, to establish lamp design rules for optimizing their optical and thermal properties. These design rules provide the means to minimize lumen depreciation over time by minimizing the periods for lamps to reach thermal steady-state while maintaining their high luminous efficacy and omnidirectional light distribution capability. While it is well known that minimizing the junction temperature of an LED leads to a longer lifetime and an increased lumen output, our study demonstrates, for the first time, to the best of our knowledge, that it is also important to minimize the time it takes to reach thermal equilibrium because doing so minimizes lumen depreciation and enhances light output and color stability during operation. Specifically, we have found that, in addition to inadequate heat-sink fin areas for a lamp configuration, LEDs mounted on multiple boards, as opposed to a single board, lead to longer periods for reaching thermal equilibrium contributing to larger lumen depreciation.

Typical Toddlers' Participation in “Just-in-Time” Programming of Vocabulary for Visual Scene Display Augmentative and Alternative Communication Apps on Mobile Technology: A Descriptive Study

PubMed Central

Drager, Kathryn; Light, Janice; Caron, Jessica Gosnell

2017-01-01

Purpose Augmentative and alternative communication (AAC) promotes communicative participation and language development for young children with complex communication needs. However, the motor, linguistic, and cognitive demands of many AAC technologies restrict young children's operational use of and influence over these technologies. The purpose of the current study is to better understand young children's participation in programming vocabulary “just in time” on an AAC application with minimized demands. Method A descriptive study was implemented to highlight the participation of 10 typically developing toddlers (M age: 16 months, range: 10–22 months) in just-in-time vocabulary programming in an AAC app with visual scene displays. Results All 10 toddlers participated in some capacity in adding new visual scene displays and vocabulary to the app just in time. Differences in participation across steps were observed, suggesting variation in the developmental demands of controls involved in vocabulary programming. Conclusions Results from the current study provide clinical insights toward involving young children in AAC programming just in time and steps that may allow for more independent participation or require more scaffolding. Technology designed to minimize motor, cognitive, and linguistic demands may allow children to participate in programming devices at a younger age. PMID:28586825

Rapid Pneumatic Transport of Radioactive Samples - RaPToRS

NASA Astrophysics Data System (ADS)

Padalino, S.; Barrios, M.; Sangster, C.

2005-10-01

Some ICF neutron activation diagnostics require quick retrieval of the activated sample. Minimizing retrieval times is particularly important when the half-life of the activated material is on the order of the transport time or the degree of radioactivity is close to the background counting level. These restrictions exist in current experiments performed at the Laboratory for Laser Energetics, thus motivating the development of the RaPToRS system. The system has been designed to minimize transportation time while requiring no human intervention during transport or counting. These factors will be important if the system is to be used at the NIF where radiological hazards will be present during post activation. The sample carrier is pneumatically transported via a 4 inch ID PVC pipe to a remote location in excess of 100 meters from the activation site at a speed of approximately 7 m/s. It arrives at an end station where it is dismounted robotically from the carrier and removed from its hermetic package. The sample is then placed by the robot in a counting station. This system is currently being developed to measure back-to-back gamma rays produced by positron annihilation which were emitted by activated graphite. Funded in part by the U.S. DOE under sub contract with LLE at the University of Rochester.

Efficient hemodynamic event detection utilizing relational databases and wavelet analysis

NASA Technical Reports Server (NTRS)

Saeed, M.; Mark, R. G.

2001-01-01

Development of a temporal query framework for time-oriented medical databases has hitherto been a challenging problem. We describe a novel method for the detection of hemodynamic events in multiparameter trends utilizing wavelet coefficients in a MySQL relational database. Storage of the wavelet coefficients allowed for a compact representation of the trends, and provided robust descriptors for the dynamics of the parameter time series. A data model was developed to allow for simplified queries along several dimensions and time scales. Of particular importance, the data model and wavelet framework allowed for queries to be processed with minimal table-join operations. A web-based search engine was developed to allow for user-defined queries. Typical queries required between 0.01 and 0.02 seconds, with at least two orders of magnitude improvement in speed over conventional queries. This powerful and innovative structure will facilitate research on large-scale time-oriented medical databases.

Self-Alining Quick-Connect Joint

NASA Technical Reports Server (NTRS)

Lucy, M. H.

1983-01-01

Quick connect tapered joint used with minimum manipulation and force. Split ring retainer holds locking ring in place. Minimal force required to position male in female joint, at which time split-ring retainers are triggered to release split locking rings. Originally developed to assemble large space structures, joint is simple, compact, strong, lightweight, self alining, and has no loose parts.

Desert Survivors: The Design and Implementation of a Television Program to Enhance Local Scientific Literacy

ERIC Educational Resources Information Center

Utz, Jenifer C.; Rausch, Candice M.; Fruth, Laurie; Thomas, Megan E.; van Breukelen, Frank

2007-01-01

Outreach efforts by faculty members are oftentimes limited in scope due to hectic schedules. We developed a program to enhance science literacy in elementary school children that allows experts to reach a tremendous audience while minimizing their time commitment. The foundation of the program is a television series entitled "Desert Survivors."…

Design and development of a freezer and chiller delivery box

NASA Astrophysics Data System (ADS)

Zakaria, Mohd Zakimi; Hung, Goh Chung; Dawi, Mohd Syedi Imran Mohd; Hussin, Radhwan; Khalil, Ahmad Nabil Mohd; Naim, Muhammad Khairy Md; Hilmi, Ahmad Humaizi

2017-09-01

This paper presents an action research of designed and fabricated using well insulating materials in order to ensure the coolness inside the freezer and chiller delivery box is as good minimize temperature raised. The main purpose of this study is to develop freeze and chiller delivery box that will be able to keep fresh meat during travelling long delivery. A range of freeze and chill solutions exists for that must be kept within a specific temperature range throughout the supply-and-distribution chain. This will help to minimize the activeness of bacteria to spoil the meats, at the same time it can linger the duration for meats to spoil. All affecting parameter such as temperature inside the delivery box, heat transfer rate, and natural convection flow pattern has been studied to design and development of the delivery box. Finally, temperature distribution analysis has been conducted which showed that in operating condition inside temperature are suitable to keep the fresh meats condition.

Real-time acquisition and tracking system with multiple Kalman filters

NASA Astrophysics Data System (ADS)

Beard, Gary C.; McCarter, Timothy G.; Spodeck, Walter; Fletcher, James E.

1994-07-01

The design of a real-time, ground-based, infrared tracking system with proven field success in tracking boost vehicles through burnout is presented with emphasis on the software design. The system was originally developed to deliver relative angular positions during boost, and thrust termination time to a sensor fusion station in real-time. Autonomous target acquisition and angle-only tracking features were developed to ensure success under stressing conditions. A unique feature of the system is the incorporation of multiple copies of a Kalman filter tracking algorithm running in parallel in order to minimize run-time. The system is capable of updating the state vector for an object at measurement rates approaching 90 Hz. This paper will address the top-level software design, details of the algorithms employed, system performance history in the field, and possible future upgrades.

[siRNAs with high specificity to the target: a systematic design by CRM algorithm].

PubMed

Alsheddi, T; Vasin, L; Meduri, R; Randhawa, M; Glazko, G; Baranova, A

2008-01-01

'Off-target' silencing effect hinders the development of siRNA-based therapeutic and research applications. Common solution to this problem is an employment of the BLAST that may miss significant alignments or an exhaustive Smith-Waterman algorithm that is very time-consuming. We have developed a Comprehensive Redundancy Minimizer (CRM) approach for mapping all unique sequences ("targets") 9-to-15 nt in size within large sets of sequences (e.g. transcriptomes). CRM outputs a list of potential siRNA candidates for every transcript of the particular species. These candidates could be further analyzed by traditional "set-of-rules" types of siRNA designing tools. For human, 91% of transcripts are covered by candidate siRNAs with kernel targets of N = 15. We tested our approach on the collection of previously described experimentally assessed siRNAs and found that the correlation between efficacy and presence in CRM-approved set is significant (r = 0.215, p-value = 0.0001). An interactive database that contains a precompiled set of all human siRNA candidates with minimized redundancy is available at http://129.174.194.243. Application of the CRM-based filtering minimizes potential "off-target" silencing effects and could improve routine siRNA applications.

A new minimal-stress freely-moving rat model for preclinical studies on intranasal administration of CNS drugs.

PubMed

Stevens, Jasper; Suidgeest, Ernst; van der Graaf, Piet Hein; Danhof, Meindert; de Lange, Elizabeth C M

2009-08-01

To develop a new minimal-stress model for intranasal administration in freely moving rats and to evaluate in this model the brain distribution of acetaminophen following intranasal versus intravenous administration. Male Wistar rats received one intranasal cannula, an intra-cerebral microdialysis probe, and two blood cannulas for drug administration and serial blood sampling respectively. To evaluate this novel model, the following experiments were conducted. 1) Evans Blue was administered to verify the selectivity of intranasal exposure. 2) During a 1 min infusion 10, 20, or 40 microl saline was administered intranasally or 250 microl intravenously. Corticosterone plasma concentrations over time were compared as biomarkers for stress. 3) 200 microg of the model drug acetaminophen was given in identical setup and plasma, and brain pharmacokinetics were determined. In 96% of the rats, only the targeted nasal cavity was deeply colored. Corticosterone plasma concentrations were not influenced, neither by route nor volume of administration. Pharmacokinetics of acetaminophen were identical after intravenous and intranasal administration, although the Cmax in microdialysates was reached a little earlier following intravenous administration. A new minimal-stress model for intranasal administration in freely moving rats has been successfully developed and allows direct comparison with intravenous administration.

Artificial neural network classification using a minimal training set - Comparison to conventional supervised classification

NASA Technical Reports Server (NTRS)

Hepner, George F.; Logan, Thomas; Ritter, Niles; Bryant, Nevin

1990-01-01

Recent research has shown an artificial neural network (ANN) to be capable of pattern recognition and the classification of image data. This paper examines the potential for the application of neural network computing to satellite image processing. A second objective is to provide a preliminary comparison and ANN classification. An artificial neural network can be trained to do land-cover classification of satellite imagery using selected sites representative of each class in a manner similar to conventional supervised classification. One of the major problems associated with recognition and classifications of pattern from remotely sensed data is the time and cost of developing a set of training sites. This reseach compares the use of an ANN back propagation classification procedure with a conventional supervised maximum likelihood classification procedure using a minimal training set. When using a minimal training set, the neural network is able to provide a land-cover classification superior to the classification derived from the conventional classification procedure. This research is the foundation for developing application parameters for further prototyping of software and hardware implementations for artificial neural networks in satellite image and geographic information processing.

Haptic Feedback in Robot-Assisted Minimally Invasive Surgery

PubMed Central

Okamura, Allison M.

2009-01-01

Purpose of Review Robot-assisted minimally invasive surgery (RMIS) holds great promise for improving the accuracy and dexterity of a surgeon while minimizing trauma to the patient. However, widespread clinical success with RMIS has been marginal. It is hypothesized that the lack of haptic (force and tactile) feedback presented to the surgeon is a limiting factor. This review explains the technical challenges of creating haptic feedback for robot-assisted surgery and provides recent results that evaluate the effectiveness of haptic feedback in mock surgical tasks. Recent Findings Haptic feedback systems for RMIS are still under development and evaluation. Most provide only force feedback, with limited fidelity. The major challenge at this time is sensing forces applied to the patient. A few tactile feedback systems for RMIS have been created, but their practicality for clinical implementation needs to be shown. It is particularly difficult to sense and display spatially distributed tactile information. The cost-benefit ratio for haptic feedback in RMIS has not been established. Summary The designs of existing commercial RMIS systems are not conducive for force feedback, and creative solutions are needed to create compelling tactile feedback systems. Surgeons, engineers, and neuroscientists should work together to develop effective solutions for haptic feedback in RMIS. PMID:19057225

Low NO sub x heavy fuel combustor concept program

NASA Technical Reports Server (NTRS)

Russell, P.; Beal, G.; Hinton, B.

1981-01-01

A gas turbine technology program to improve and optimize the staged rich lean low NOx combustor concept is described. Subscale combustor tests to develop the design information for optimization of the fuel preparation, rich burn, quick air quench, and lean burn steps of the combustion process were run. The program provides information for the design of high pressure full scale gas turbine combustors capable of providing environmentally clean combustion of minimally of minimally processed and synthetic fuels. It is concluded that liquid fuel atomization and mixing, rich zone stoichiometry, rich zone liner cooling, rich zone residence time, and quench zone stoichiometry are important considerations in the design and scale up of the rich lean combustor.

The history of in-flight exercise in the US manned space program

NASA Technical Reports Server (NTRS)

Moore, Thomas P.

1989-01-01

A historical perspective on in-flight exercise in the U.S. manned space program is given. We have learned a great deal in the 25 years since the inception of Project Mercury. But, as we look forward to a Space Station and long-duration space flight, we must recognize the challenge that lies ahead. The importance of maintenance of the crewmember's physical condition during long stays in weightlessness is a prime concern that should not be minimized. The challenge lies in the design and development of exercise equipment and protocols that will prevent or minimize the deleterious sequelae of long-duration space flight while maximizing valuable on-orbit crew time.

ONLINE MINIMIZATION OF VERTICAL BEAM SIZES AT APS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Yipeng

In this paper, online minimization of vertical beam sizes along the APS (Advanced Photon Source) storage ring is presented. A genetic algorithm (GA) was developed and employed for the online optimization in the APS storage ring. A total of 59 families of skew quadrupole magnets were employed as knobs to adjust the coupling and the vertical dispersion in the APS storage ring. Starting from initially zero current skew quadrupoles, small vertical beam sizes along the APS storage ring were achieved in a short optimization time of one hour. The optimization results from this method are briefly compared with the onemore » from LOCO (Linear Optics from Closed Orbits) response matrix correction.« less

Enhanced visualization of the bile duct via parallel white light and indocyanine green fluorescence laparoscopic imaging

NASA Astrophysics Data System (ADS)

Demos, Stavros G.; Urayama, Shiro

2014-03-01

Despite best efforts, bile duct injury during laparoscopic cholecystectomy is a major potential complication. Precise detection method of extrahepatic bile duct during laparoscopic procedures would minimize the risk of injury. Towards this goal, we have developed a compact imaging instrumentation designed to enable simultaneous acquisition of conventional white color and NIR fluorescence endoscopic/laparoscopic imaging using ICG as contrast agent. The capabilities of this system, which offers optimized sensitivity and functionality, are demonstrated for the detection of the bile duct in an animal model. This design could also provide a low-cost real-time surgical navigation capability to enhance the efficacy of a variety of other image-guided minimally invasive procedures.

Optimal feedback control of turbulent channel flow

NASA Technical Reports Server (NTRS)

Bewley, Thomas; Choi, Haecheon; Temam, Roger; Moin, Parviz

1993-01-01

Feedback control equations were developed and tested for computing wall normal control velocities to control turbulent flow in a channel with the objective of reducing drag. The technique used is the minimization of a 'cost functional' which is constructed to represent some balance of the drag integrated over the wall and the net control effort. A distribution of wall velocities is found which minimizes this cost functional some time shortly in the future based on current observations of the flow near the wall. Preliminary direct numerical simulations of the scheme applied to turbulent channel flow indicates it provides approximately 17 percent drag reduction. The mechanism apparent when the scheme is applied to a simplified flow situation is also discussed.

Development of action levels for MED/MPD skin-testing units in ultraviolet phototherapy

NASA Astrophysics Data System (ADS)

O'Connor, Una M.; O'Hare, Neil J.

2003-03-01

Ultraviolet (UV) Phototherapy is commonly used for treatment of skin diseases such as psoriasis and eczema. Treatment is carried out using UV phototherapy units, exposing all or part of the body for a certain exposure time. Prior to exposure in treatment units, an unaffected area of skin may be tested using UV skin-testing units in order to determine a suitable treatment regime. The exposure time at which barely perceptible erythema has developed is known as the Minimal Erythemal Dose (MED) for UVB therapy and Minimal Phototoxic Dose (MPD) for UVA therapy. This is used to determine the starting dose in the treatment regime. The presence of 'hotspots' and 'coldspots' in UV skin-testing units can result in inaccurate determination of MED/MPD. This could give rise to severe burns during treatment, or in a sub-optimal dose regime being used. Quality assurance protocols for UV phototherapy equipment have recently been developed and these protocols have highlighted the need for action levels for skin-testing units. An action level is a reference value, which is used to determine whether the difference in irradiance output level across a UV unit is acceptable. Current methodologies for skin-testing in Ireland have been characterised and errors introduced during testing have been estimated. Action levels have been developed based on analysis of errors and requirements of skin-testing.

Development and Implementation of a Coagulation Factor Testing Method Utilizing Autoverification in a High-volume Clinical Reference Laboratory Environment

PubMed Central

Riley, Paul W.; Gallea, Benoit; Valcour, Andre

2017-01-01

Background: Testing coagulation factor activities requires that multiple dilutions be assayed and analyzed to produce a single result. The slope of the line created by plotting measured factor concentration against sample dilution is evaluated to discern the presence of inhibitors giving rise to nonparallelism. Moreover, samples producing results on initial dilution falling outside the analytic measurement range of the assay must be tested at additional dilutions to produce reportable results. Methods: The complexity of this process has motivated a large clinical reference laboratory to develop advanced computer algorithms with automated reflex testing rules to complete coagulation factor analysis. A method was developed for autoverification of coagulation factor activity using expert rules developed with on an off the shelf commercially available data manager system integrated into an automated coagulation platform. Results: Here, we present an approach allowing for the autoverification and reporting of factor activity results with greatly diminished technologist effort. Conclusions: To the best of our knowledge, this is the first report of its kind providing a detailed procedure for implementation of autoverification expert rules as applied to coagulation factor activity testing. Advantages of this system include ease of training for new operators, minimization of technologist time spent, reduction of staff fatigue, minimization of unnecessary reflex tests, optimization of turnaround time, and assurance of the consistency of the testing and reporting process. PMID:28706751

Development and Implementation of a Coagulation Factor Testing Method Utilizing Autoverification in a High-volume Clinical Reference Laboratory Environment.

PubMed

Riley, Paul W; Gallea, Benoit; Valcour, Andre

2017-01-01

Testing coagulation factor activities requires that multiple dilutions be assayed and analyzed to produce a single result. The slope of the line created by plotting measured factor concentration against sample dilution is evaluated to discern the presence of inhibitors giving rise to nonparallelism. Moreover, samples producing results on initial dilution falling outside the analytic measurement range of the assay must be tested at additional dilutions to produce reportable results. The complexity of this process has motivated a large clinical reference laboratory to develop advanced computer algorithms with automated reflex testing rules to complete coagulation factor analysis. A method was developed for autoverification of coagulation factor activity using expert rules developed with on an off the shelf commercially available data manager system integrated into an automated coagulation platform. Here, we present an approach allowing for the autoverification and reporting of factor activity results with greatly diminished technologist effort. To the best of our knowledge, this is the first report of its kind providing a detailed procedure for implementation of autoverification expert rules as applied to coagulation factor activity testing. Advantages of this system include ease of training for new operators, minimization of technologist time spent, reduction of staff fatigue, minimization of unnecessary reflex tests, optimization of turnaround time, and assurance of the consistency of the testing and reporting process.

[Development of premature children: caregivers' understanding according to the Bioecological Theory].

PubMed

Lemos, Rayla Amaral; Veríssimo, Maria de La Ó Ramallo

2015-12-01

Understanding the conceptions of premature children caregivers on child development and associated factors. An exploratory-descriptive qualitative study of 12 families with children under three years of age. Interviews were submitted to thematic content analysis, systematized into the categories of Bioecological Theory of Human Development: Process, Person, Context and Time, and in the Functional Development category. There are concerns about impairment in the current and future development of a Person/child defined as fragile as a result of premature birth (Time dimension), minimized by the scope of observable competencies such as motor skills. The Context, especially family and health services, and Proximal Processes, described as one-way caregiver interactions, are considered determinants of development. Functional Development is considered a natural consequence and result of education. The support network is crucial, supporting or limiting care. Concerns about the development mobilize caregivers to stimulate the premature child/person and requests family and healthcare assistance.

Minimally invasive excision of gynaecomastia--a novel and effective surgical technique.

PubMed

Qutob, O; Elahi, B; Garimella, V; Ihsan, N; Drew, P J

2010-04-01

More aesthetically acceptable treatment options have been sought to minimise the morbidity associated with open surgery for gynaecomastia. This study investigated the use of a vacuum-assisted biopsy device (VABD) and liposuction to provide minimally invasive approach. Patients diagnosed with idiopathic benign gynaecomastia referred to the Breast Care Unit of Castle Hill Hospital between June 2002 and April 2007 and requesting surgical intervention underwent VABD excision and liposuction. All patients underwent thorough investigations to exclude any underlying cause for their gynaecomastia. The procedure was carried out by a single consultant surgeon with special interest in breast surgery. An 8-G mammotome probe was advanced through a 4-mm incision positioned in the corresponding anterior axillary line to excise the glandular disc. Liposuction was performed through the same incision. Incision wounds were closed with Steristrips. A pressure dressing was applied over wound by corset and an inflatable device. Thirty-six male patients with grade I and II gynaecomastia were recruited (22 bilateral, 14 unilateral). Average age was 33.3 years (range, 16-88 years). All underwent mammotome excision and liposuction. There were no conversions to an open procedure. The average procedure time was 50.3 min (range, 30-80 min). One intra-operative complication was recorded. The minimum follow-up time was 2 months. Thirty-four patients reported excellent satisfaction, two patients had residual gynaecomastia and needed a re-do procedure. Three patients developed small haematomas that resolved spontaneously. This novel, minimally invasive, surgical approach for gynaecomastia gives excellent results with minimal morbidity.

First metatarsal closing base wedge osteotomy using real-time fluoroscopy.

PubMed

Toepp, F C; Salcedo, M

1991-01-01

A minimal incision surgery approach to metatarsus primus adductus is presented. The percutaneous closing base wedge osteotomy is performed using real-time intraoperative fluoroscopy. The advantages and disadvantages of this minimal incision surgical procedure are discussed.

Innovative Ingredients and Emerging Technologies for Controlling Ice Recrystallization, Texture, and Structure Stability in Frozen Dairy Desserts: A Review.

PubMed

Soukoulis, Christos; Fisk, Ian

2016-11-17

Over the past decade, ice cream manufacturers have developed a strong understanding of the functionality of key ingredients and processing, developing effective explanations for the link between structure forming agents, stability mechanisms, and perceived quality. Increasing demand for products perceived as healthier/more natural with minimal processing has identified a number of new tools to improve quality and storage stability of frozen dairy desserts. Ingredients such as dietary fiber, polysaccharides, prebiotics, alternate sweeteners, fat sources rich in unsaturated fatty acids and ice strucsturing proteins (ISP) have been successfully applied as cryoprotective, texturizing, and structuring agents. Emerging minimal processing technologies including hydrostatic pressure processing, ultrasonic or high pressure assisted freezing, low temperature extrusion and enzymatically induced biopolymers crosslinking have been evaluated for their ability to improve colloidal stability, texture and sensory quality. It is therefore timely for a comprehensive review.

Screening for Barrett’s Esophagus

PubMed Central

di Pietro, Massimiliano; Chan, Daniel; Fitzgerald, Rebecca C.; Wang, Kenneth K.

2015-01-01

The large increase in the incidence of esophageal adeno-carcinoma in the West during the past 30 years has stimulated interest in screening for Barrett’s esophagus (BE), a precursor to esophageal cancer. Effective endoscopic treatments for dysplasia and intramucosal cancer, coupled with screening programs to detect BE, could help reverse the increase in the incidence of esophageal cancer. However, there are no accurate, cost-effective, minimally invasive techniques available to screen for BE, reducing the enthusiasm of gastroenterologists. Over the past 5 years, there has been significant progress in the development of screening technologies. We review existing and developing technologies, new minimally invasive imaging techniques, nonendoscopic devices for cell collection, and biomarkers that can be measured in blood or stool samples. We discuss the status of these approaches, data from clinical studies of their effects, and their anticipated strengths and weaknesses in screening. The area is rapidly evolving, and new tools will soon be ready for prime time. PMID:25701083

Latest trends in craniomaxillofacial surgical instrumentation.

PubMed

Yim, Michael; Demke, Joshua

2012-08-01

To review the past year's literature regarding recent innovations in surgical instrumentation for craniomaxillofacial surgery. Current advances in surgical instrumentation have led to many improvements in the field, allowing greater visualization and precision both before and during procedures. One of the common goals is to achieve excellent outcomes with minimal complications, while at the same time minimizing invasiveness of surgery. Highlighted innovations include greater capacities for acquisition of data, leading to improved imaging modalities and expansion of computer-assisted surgical techniques; continued developments in biomaterials used in various reconstructions; and novel uses of bone cutting and bone fixation instrumentation. Technology in the field of craniomaxillofacial surgery is developing rapidly, leading to novel instrumentation being utilized across a broad spectrum of areas. Published data have been encouraging to date, indicating an ever increasing adaptation of these innovations in clinical practice. Future efforts need to focus on cost-benefit analysis and constructing larger-scale studies to better understand effectiveness and patient outcomes.

Coupling mechanical tension and GTPase signaling to generate cell and tissue dynamics

NASA Astrophysics Data System (ADS)

Zmurchok, Cole; Bhaskar, Dhananjay; Edelstein-Keshet, Leah

2018-07-01

Regulators of the actin cytoskeleton such Rho GTPases can modulate forces developed in cells by promoting actomyosin contraction. At the same time, through mechanosensing, tension is known to affect the activity of Rho GTPases. What happens when these effects act in concert? Using a minimal model (1 GTPase coupled to a Kelvin–Voigt element), we show that two-way feedback between signaling (‘RhoA’) and mechanical tension (stretching) leads to a spectrum of cell behaviors, including contracted or relaxed cells, and cells that oscillate between these extremes. When such ‘model cells’ are connected to one another in a row or in a 2D sheet (‘epithelium’), we observe waves of contraction/relaxation and GTPase activity sweeping through the tissue. The minimal model lends itself to full bifurcation analysis, and suggests a mechanism that explains behavior observed in the context of development and collective cell behavior.

Real-Time Adaptive Least-Squares Drag Minimization for Performance Adaptive Aeroelastic Wing

NASA Technical Reports Server (NTRS)

Ferrier, Yvonne L.; Nguyen, Nhan T.; Ting, Eric

2016-01-01

This paper contains a simulation study of a real-time adaptive least-squares drag minimization algorithm for an aeroelastic model of a flexible wing aircraft. The aircraft model is based on the NASA Generic Transport Model (GTM). The wing structures incorporate a novel aerodynamic control surface known as the Variable Camber Continuous Trailing Edge Flap (VCCTEF). The drag minimization algorithm uses the Newton-Raphson method to find the optimal VCCTEF deflections for minimum drag in the context of an altitude-hold flight control mode at cruise conditions. The aerodynamic coefficient parameters used in this optimization method are identified in real-time using Recursive Least Squares (RLS). The results demonstrate the potential of the VCCTEF to improve aerodynamic efficiency for drag minimization for transport aircraft.

Risk, Issues and Lessons Learned: Maximizing Risk Management in the DoD Ground Domain

DTIC Science & Technology

2011-10-01

Carnegie Mellon University “Risk Management Overview for TACOM” Benefits of Risk Management include: • Risk is a proactive approach - preventing... Chili (no beans) 13 • Hot dog sub-assy Unclassified How does the FMEA work? Execute the analysis and discover the potential failures and effects...34 - --· . -· A c u i.rition Benefits of FMEAs • Prevent major risks, reduce failures, minimize cost and reduce development time - Do it right the first time

Development of a Paradigm to Assess Nutritive and Biochemical Substances in Humans: A Preliminary Report on the Effects of Tyrosine upon Altitude- and Cold-Induced Stress Responses

DTIC Science & Technology

1987-03-01

3/4 hours. Performance tests evaluated simple and choice reaction time to visual stimuli, vigilance, and processing of symbolic, numerical, verbal...minimize the adverse consequences of these stressors. Tyrosine enhanced performance (e.g. complex information processing , vigilance, and reaction time... processes inherent in many real-world tasks. For example, Map Compass requires association of Wsi PL AFCm uA O-SV CHETCLtISS) direction and degree

Minimal camera networks for 3D image based modeling of cultural heritage objects.

PubMed

Alsadik, Bashar; Gerke, Markus; Vosselman, George; Daham, Afrah; Jasim, Luma

2014-03-25

3D modeling of cultural heritage objects like artifacts, statues and buildings is nowadays an important tool for virtual museums, preservation and restoration. In this paper, we introduce a method to automatically design a minimal imaging network for the 3D modeling of cultural heritage objects. This becomes important for reducing the image capture time and processing when documenting large and complex sites. Moreover, such a minimal camera network design is desirable for imaging non-digitally documented artifacts in museums and other archeological sites to avoid disturbing the visitors for a long time and/or moving delicate precious objects to complete the documentation task. The developed method is tested on the Iraqi famous statue "Lamassu". Lamassu is a human-headed winged bull of over 4.25 m in height from the era of Ashurnasirpal II (883-859 BC). Close-range photogrammetry is used for the 3D modeling task where a dense ordered imaging network of 45 high resolution images were captured around Lamassu with an object sample distance of 1 mm. These images constitute a dense network and the aim of our study was to apply our method to reduce the number of images for the 3D modeling and at the same time preserve pre-defined point accuracy. Temporary control points were fixed evenly on the body of Lamassu and measured by using a total station for the external validation and scaling purpose. Two network filtering methods are implemented and three different software packages are used to investigate the efficiency of the image orientation and modeling of the statue in the filtered (reduced) image networks. Internal and external validation results prove that minimal image networks can provide highly accurate records and efficiency in terms of visualization, completeness, processing time (>60% reduction) and the final accuracy of 1 mm.

Minimal Camera Networks for 3D Image Based Modeling of Cultural Heritage Objects

PubMed Central

Alsadik, Bashar; Gerke, Markus; Vosselman, George; Daham, Afrah; Jasim, Luma

2014-01-01

3D modeling of cultural heritage objects like artifacts, statues and buildings is nowadays an important tool for virtual museums, preservation and restoration. In this paper, we introduce a method to automatically design a minimal imaging network for the 3D modeling of cultural heritage objects. This becomes important for reducing the image capture time and processing when documenting large and complex sites. Moreover, such a minimal camera network design is desirable for imaging non-digitally documented artifacts in museums and other archeological sites to avoid disturbing the visitors for a long time and/or moving delicate precious objects to complete the documentation task. The developed method is tested on the Iraqi famous statue “Lamassu”. Lamassu is a human-headed winged bull of over 4.25 m in height from the era of Ashurnasirpal II (883–859 BC). Close-range photogrammetry is used for the 3D modeling task where a dense ordered imaging network of 45 high resolution images were captured around Lamassu with an object sample distance of 1 mm. These images constitute a dense network and the aim of our study was to apply our method to reduce the number of images for the 3D modeling and at the same time preserve pre-defined point accuracy. Temporary control points were fixed evenly on the body of Lamassu and measured by using a total station for the external validation and scaling purpose. Two network filtering methods are implemented and three different software packages are used to investigate the efficiency of the image orientation and modeling of the statue in the filtered (reduced) image networks. Internal and external validation results prove that minimal image networks can provide highly accurate records and efficiency in terms of visualization, completeness, processing time (>60% reduction) and the final accuracy of 1 mm. PMID:24670718

Advanced data acquisition and display techniques for laser velocimetry

NASA Technical Reports Server (NTRS)

Kjelgaard, Scott O.; Weston, Robert P.

1991-01-01

The Basic Aerodynamics Research Tunnel (BART) has been equipped with state-of-the-art instrumentation for acquiring the data needed for code validation. This paper describes the three-component LDV and the workstation-based data-acquisition system (DAS) which has been developed for the BART. The DAS allows the use of automation and the quick integration of advanced instrumentation, while minimizing the software development time required between investigations. The paper also includes a description of a graphics software library developed to support the windowing environment of the DAS. The real-time displays generated using the graphics library help the researcher ensure the test is proceeding properly. The graphics library also supports the requirements of posttest data analysis. The use of the DAS and graphics libraries is illustrated by presenting examples of the real-time and postprocessing display graphics for LDV investigations.

Effect of Surface Traffic Count on Taxi Time at Dallas-Fort Worth (DFW) International Airport

NASA Technical Reports Server (NTRS)

Kistler, Matthew Stephen; Gupta, Gautam

2008-01-01

As the amount of air traffic increases over the years, most airports simply do not have the means of expanding to handle the intensified traffic on the surface that will ensue. Precise surveillance equipment and automation concepts, as well as advanced surface traffic algorithms are being developed to improve airport efficiency. These surface algorithms require inputs unique to each airport to ensure maximum efficiency, and minimal taxi delay. This study analyzes surface traffic at Dallas-Fort Worth International Airport (DFW) to determine the effect of the number of aircraft on the surface and the amount of stop and go situations they experience to the amount of additional taxi time encountered. If the surface capacity of an airport is known, minimal delay can be accomplished by limiting the number of taxiing aircraft to that capacity. This concept is related to highways, where traffic flow drastically decreases as more cars occupy the road. An attempt to minimize this effect on highways is seen with the use of metering lights at freeway on-ramps. Since the surface traffic at airports is highly regulated, and aircraft are less mobile on the ground, limiting the surface count to a certain number can greatly reduce the amount of additional taxi time encountered, as well as reduce hazardous emissions. This study will also find the regions of an airport that encounter the most additional taxi time when the number of aircraft in that area is increased. This could help surface traffic algorithms avoid congesting that area, or re-route aircraft to different runways when that area reaches its capacity. The relationship between the amount of stop and go situations an aircraft encounters and their effect on the taxi time of that aircraft will also be investigated. This will help to determine the effect of holding an aircraft on the taxiway as opposed to re-routing it. The lesser of the two should be used when developing surface traffic algorithms to further minimize the delay encountered. The fields investigated in this study include taxi time, the number of aircraft on the surface, the number of stop and go situations, and the time stopped for each aircraft. Taxi time is defined as spot to runway for departures, and runway to spot for arrivals. It does not include ramp area taxi time because the ramp area is controlled differently, and surface traffic schedulers do not currently incorporate them. Taxi time is found by finding the difference between take-off time (OFF) and spot crossing time for departures, and spot crossing time and landing time (ON) for arrivals. All surface data was either found directly using the Surface Operations Data Analysis and Adaptation (SODAA), a tool to analyze the Surface Management System (SMS) generated log files, or indirectly from SODAA using Matlab to derive values from SODAA data. The number of aircraft on the surface is found by looping through the ON times, OFF times, and spot times for each aircraft during a particular day. For each departure aircraft, surface counts are taken at its spot crossing and OFF time. The average of these two is used as the surface count for that aircraft. For arrivals, surface counts are taken at its ON time and its spot crossing time. The average of these two is used.

Lunar settlements - A socio-economic outlook

NASA Technical Reports Server (NTRS)

Bluth, B. J.

1986-01-01

Factors in the design and development of a lunar settlement (LS) which affect the performance of the crew members are discussed. Topics examined include LS-program time constraints imposed by decisions made in developing and operating the Space Station; changes to make allowance for the long-term requirements of LSs; the design of the physical, technical, and organic LS environment; and the vital role of group dynamics in assuring LS success. It is suggested that many short-term cost-minimization strategies employed in spacecraft development may be inappropriate for LS programs.

One approach for evaluating the Distributed Computing Design System (DCDS)

NASA Technical Reports Server (NTRS)

Ellis, J. T.

1985-01-01

The Distributed Computer Design System (DCDS) provides an integrated environment to support the life cycle of developing real-time distributed computing systems. The primary focus of DCDS is to significantly increase system reliability and software development productivity, and to minimize schedule and cost risk. DCDS consists of integrated methodologies, languages, and tools to support the life cycle of developing distributed software and systems. Smooth and well-defined transistions from phase to phase, language to language, and tool to tool provide a unique and unified environment. An approach to evaluating DCDS highlights its benefits.

Fission Technology for Exploring and Utilizing the Solar System

NASA Technical Reports Server (NTRS)

Houts, Mike; VanDyke, Melissa; Godfroy, Tom; Pedersen, Kevin; Martin, James; Dickens, Ricky; Salvail, Pat; Hrbub, Ivana; Schmidt, George R. (Technical Monitor)

2000-01-01

Fission technology can enable rapid, affordable access to any point in the solar system. Potential fission-based transportation options include bimodal nuclear thermal rockets, high specific energy propulsion systems, and pulsed fission propulsion systems. In-space propellant re-supply enhances the effective performance of all systems, but requires significant infrastructure development. Safe, timely, affordable utilization of first-generation space fission propulsion systems will enable the development of more advanced systems. First generation space systems will build on over 45 years of US and international space fission system technology development to minimize cost,

Screen time and young children: Promoting health and development in a digital world.

PubMed

2017-11-01

The digital landscape is evolving more quickly than research on the effects of screen media on the development, learning and family life of young children. This statement examines the potential benefits and risks of screen media in children younger than 5 years, focusing on developmental, psychosocial and physical health. Evidence-based guidance to optimize and support children's early media experiences involves four principles: minimizing, mitigating, mindfully using and modelling healthy use of screens. Knowing how young children learn and develop informs best practice strategies for health care providers.

Minimally Invasive Surgical Pulmonary Embolectomy: A Potential Alternative to Conventional Sternotomy.

PubMed

Pasrija, Chetan; Shah, Aakash; Sultanik, Elliot; Rouse, Michael; Ghoreishi, Mehrdad; Bittle, Gregory J; Boulos, Francesca; Griffith, Bartley P; Kon, Zachary N

Surgical pulmonary embolectomy has gained increasing popularity over the past decade with multiple series reporting excellent outcomes in the treatment of submassive pulmonary embolism. However, a significant barrier to the broader adoption of surgical pulmonary embolectomy remains the large incision and long recovery after a full sternotomy. We report the safety and efficacy of using a minimally invasive approach to surgical pulmonary embolectomy. All consecutive patients undergoing surgical pulmonary embolectomy for a submassive pulmonary embolism (2015-2017) were reviewed. Patients were stratified as conventional or minimally invasive. The minimally invasive approach included a 5- to 7-cm skin incision with upper hemisternotomy to the third intercostal space. The primary outcomes were in-hospital and 90-day survival. Thirty patients (conventional = 20, minimally invasive = 10) were identified. Operative time was similar between the two groups, but cardiopulmonary bypass time was significantly longer in the minimally invasive group (58 vs 94 minutes, P = 0.04). While ventilator time and intensive care unit length of stay were similar between groups, hospital length of stay was 4.5 days shorter in the minimally invasive group, and there was a trend toward less blood product use. In-hospital and 90-day survival was 100%. Within the minimally invasive cohort, median right ventricular dysfunction at discharge was none-mild and no patient experienced postoperative renal failure, deep sternal wound infection, sepsis, or stroke. Minimally invasive surgical pulmonary embolectomy appears to be a feasible approach in the treatment of patients with a submassive pulmonary embolism. A larger, prospective analysis comparing this modality with conventional surgical pulmonary embolectomy may be warranted.

Connection details for prefabricated bridge elements and systems.

DOT National Transportation Integrated Search

2009-03-30

Prefabricated components of a bridge produced off-site can be assembled quickly, and can reduce design time and cost, minimizing forming, minimize lane closure time and/or possibly eliminate the need for a temporary bridge. This document has been dev...

Covariant hamiltonian spin dynamics in curved space-time

NASA Astrophysics Data System (ADS)

d'Ambrosi, G.; Satish Kumar, S.; van Holten, J. W.

2015-04-01

The dynamics of spinning particles in curved space-time is discussed, emphasizing the hamiltonian formulation. Different choices of hamiltonians allow for the description of different gravitating systems. We give full results for the simplest case with minimal hamiltonian, constructing constants of motion including spin. The analysis is illustrated by the example of motion in Schwarzschild space-time. We also discuss a non-minimal extension of the hamiltonian giving rise to a gravitational equivalent of the Stern-Gerlach force. We show that this extension respects a large class of known constants of motion for the minimal case.

Free time minimizers for the three-body problem

NASA Astrophysics Data System (ADS)

Moeckel, Richard; Montgomery, Richard; Sánchez Morgado, Héctor

2018-03-01

Free time minimizers of the action (called "semi-static" solutions by Mañe in International congress on dynamical systems in Montevideo (a tribute to Ricardo Mañé), vol 362, pp 120-131, 1996) play a central role in the theory of weak KAM solutions to the Hamilton-Jacobi equation (Fathi in Weak KAM Theorem in Lagrangian Dynamics Preliminary Version Number 10, 2017). We prove that any solution to Newton's three-body problem which is asymptotic to Lagrange's parabolic homothetic solution is eventually a free time minimizer. Conversely, we prove that every free time minimizer tends to Lagrange's solution, provided the mass ratios lie in a certain large open set of mass ratios. We were inspired by the work of Da Luz and Maderna (Math Proc Camb Philos Soc 156:209-227, 1980) which showed that every free time minimizer for the N-body problem is parabolic and therefore must be asymptotic to the set of central configurations. We exclude being asymptotic to Euler's central configurations by a second variation argument. Central configurations correspond to rest points for the McGehee blown-up dynamics. The large open set of mass ratios are those for which the linearized dynamics at each Euler rest point has a complex eigenvalue.

Life history traits in selfing versus outcrossing annuals: exploring the 'time-limitation' hypothesis for the fitness benefit of self-pollination

PubMed Central

Snell, Rebecca; Aarssen, Lonnie W

2005-01-01

Background Most self-pollinating plants are annuals. According to the 'time-limitation' hypothesis, this association between selfing and the annual life cycle has evolved as a consequence of strong r-selection, involving severe time-limitation for completing the life cycle. Under this model, selection from frequent density-independent mortality in ephemeral habitats minimizes time to flower maturation, with selfing as a trade-off, and / or selection minimizes the time between flower maturation and ovule fertilization, in which case selfing has a direct fitness benefit. Predictions arising from this hypothesis were evaluated using phylogenetically-independent contrasts of several life history traits in predominantly selfing versus outcrossing annuals from a data base of 118 species distributed across 14 families. Data for life history traits specifically related to maturation and pollination times were obtained by monitoring the start and completion of different stages of reproductive development in a greenhouse study of selfing and outcrossing annuals from an unbiased sample of 25 species involving five pair-wise family comparisons and four pair-wise genus comparisons. Results Selfing annuals in general had significantly shorter plant heights, smaller flowers, shorter bud development times, shorter flower longevity and smaller seed sizes compared with their outcrossing annual relatives. Age at first flower did not differ significantly between selfing and outcrossing annuals. Conclusions This is the first multi-species study to report these general life-history differences between selfers and outcrossers among annuals exclusively. The results are all explained more parsimoniously by selection associated with time-limitation than by selection associated with pollinator/mate limitation. The shorter bud development time reported here for selfing annuals is predicted explicitly by the time-limitation hypothesis for the fitness benefit of selfing (and not by the alternative 'reproductive assurance' hypothesis associated with pollinator/mate limitation). Support for the time-limitation hypothesis is also evident from published surveys: whereas selfers and outcrossers are about equally represented among annual species as a whole, selfers occur in much higher frequencies among the annual species found in two of the most severely time-limited habitats where flowering plants grow – deserts and cultivated habitats. PMID:15707481

Oral Insulin Delivery in a Physiologic Context: Review

PubMed Central

Arbit, Ehud; Kidron, Miriam

2017-01-01

Insulin remains indispensable to the treatment of diabetes, but its availability in injectable form only has hampered its timely and broader use. The development of an oral insulin remains an ultimate goal to both enhance ease of use, and to provide therapeutic advantages rooted in its direct delivery to the portal vein and liver. By mimicking the physiological path taken by pancreatic insulin, oral insulin is expected to have a distinct effect on the hepatic aspect of carbohydrate metabolism, hepatic insulin resistance, and, at the same time, avoid hyperinsulinemia and minimize the risk of hypoglycemia. With oral insulin approaching late stages of development, the goal of this review is to examine oral insulin in a physiological context and report on recent progress in its development. PMID:28654313

Designer drugs: the evolving science of drug discovery.

PubMed

Wanke, L A; DuBose, R F

1998-07-01

Drug discovery and design are fundamental to drug development. Until recently, most drugs were discovered through random screening or developed through molecular modification. New technologies are revolutionizing this phase of drug development. Rational drug design, using powerful computers and computational chemistry and employing X-ray crystallography, nuclear magnetic resonance spectroscopy, and three-dimensional quantitative structure activity relationship analysis, is creating highly specific, biologically active molecules by virtual reality modeling. Sophisticated screening technologies are eliminating all but the most active lead compounds. These new technologies promise more efficacious, safe, and cost-effective medications, while minimizing drug development time and maximizing profits.

MO-G-18C-05: Real-Time Prediction in Free-Breathing Perfusion MRI

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, H; Liu, W; Ruan, D

Purpose: The aim is to minimize frame-wise difference errors caused by respiratory motion and eliminate the need for breath-holds in magnetic resonance imaging (MRI) sequences with long acquisitions and repeat times (TRs). The technique is being applied to perfusion MRI using arterial spin labeling (ASL). Methods: Respiratory motion prediction (RMP) using navigator echoes was implemented in ASL. A least-square method was used to extract the respiratory motion information from the 1D navigator. A generalized artificial neutral network (ANN) with three layers was developed to simultaneously predict 10 time points forward in time and correct for respiratory motion during MRI acquisition.more » During the training phase, the parameters of the ANN were optimized to minimize the aggregated prediction error based on acquired navigator data. During realtime prediction, the trained ANN was applied to the most recent estimated displacement trajectory to determine in real-time the amount of spatial Results: The respiratory motion information extracted from the least-square method can accurately represent the navigator profiles, with a normalized chi-square value of 0.037±0.015 across the training phase. During the 60-second training phase, the ANN successfully learned the respiratory motion pattern from the navigator training data. During real-time prediction, the ANN received displacement estimates and predicted the motion in the continuum of a 1.0 s prediction window. The ANN prediction was able to provide corrections for different respiratory states (i.e., inhalation/exhalation) during real-time scanning with a mean absolute error of < 1.8 mm. Conclusion: A new technique enabling free-breathing acquisition during MRI is being developed. A generalized ANN development has demonstrated its efficacy in predicting a continuum of motion profile for volumetric imaging based on navigator inputs. Future work will enhance the robustness of ANN and verify its effectiveness with human subjects. Research supported by National Institutes of Health National Cancer Institute Grant R01 CA159471-01.« less

Impact force identification for composite helicopter blades using minimal sensing

NASA Astrophysics Data System (ADS)

Budde, Carson N.

In this research a method for online impact identification using minimal sensors is developed for rotor hubs with composite blades. Modal impact data and the corresponding responses are recorded at several locations to develop a frequency response function model for each composite blade on the rotor hub. The frequency response model for each blade is used to develop an impact identification algorithm which can be used to identify the location and magnitude of impacts. Impacts are applied in two experimental setups, including a four-blade spin test rig and a cantilevered full-sized composite blade. The impacts are estimated to have been applied at the correct location 92.3% of the time for static fiberglass blades, 97.4% of the time for static carbon fiber blades and 99.2% of the time for a full sized-static blade. The estimated location is assessed further and determined to have been estimated in the correct chord position 96.1% of the time for static fiberglass, 100% of the time for carbon fiber blades and 99.2% of the time for the full-sized blades. Projectile impacts are also applied statically and during rotation to the carbon fiber blades on the spin test rig at 57 and 83 RPM. The applied impacts can be located to the correct position 63.9%, 41.7% and 33.3% for the 0, 57 and 83 RPM speeds, respectively, while the correct chord location is estimated 100% of the time. The impact identification algorithm also estimates the force of an impact with an average percent difference of 4.64, 2.61 and 1.00 for static fiberglass, full sized, and carbon fiber blades, respectively. Using a load cell and work equations, the force of impact for a projectile fired from a dynamic firing setup is estimated at about 400 N. The average force measured for applied projectile impacts to the carbon fiber blades, rotating at 0, 57 and 83 RPM, is 368.8, 373.7 and 432.4 N, respectively.

Determining the Minimal Required Radioactivity of 18F-FDG for Reliable Semiquantification in PET/CT Imaging: A Phantom Study.

PubMed

Chen, Ming-Kai; Menard, David H; Cheng, David W

2016-03-01

In pursuit of as-low-as-reasonably-achievable (ALARA) doses, this study investigated the minimal required radioactivity and corresponding imaging time for reliable semiquantification in PET/CT imaging. Using a phantom containing spheres of various diameters (3.4, 2.1, 1.5, 1.2, and 1.0 cm) filled with a fixed (18)F-FDG concentration of 165 kBq/mL and a background concentration of 23.3 kBq/mL, we performed PET/CT at multiple time points over 20 h of radioactive decay. The images were acquired for 10 min at a single bed position for each of 10 half-lives of decay using 3-dimensional list mode and were reconstructed into 1-, 2-, 3-, 4-, 5-, and 10-min acquisitions per bed position using an ordered-subsets expectation maximum algorithm with 24 subsets and 2 iterations and a gaussian 2-mm filter. SUVmax and SUVavg were measured for each sphere. The minimal required activity (±10%) for precise SUVmax semiquantification in the spheres was 1.8 kBq/mL for an acquisition of 10 min, 3.7 kBq/mL for 3-5 min, 7.9 kBq/mL for 2 min, and 17.4 kBq/mL for 1 min. The minimal required activity concentration-acquisition time product per bed position was 10-15 kBq/mL⋅min for reproducible SUV measurements within the spheres without overestimation. Using the total radioactivity and counting rate from the entire phantom, we found that the minimal required total activity-time product was 17 MBq⋅min and the minimal required counting rate-time product was 100 kcps⋅min. Our phantom study determined a threshold for minimal radioactivity and acquisition time for precise semiquantification in (18)F-FDG PET imaging that can serve as a guide in pursuit of achieving ALARA doses. © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

Toward the International Classification of Functioning, Disability and Health (ICF) Rehabilitation Set: A Minimal Generic Set of Domains for Rehabilitation as a Health Strategy.

PubMed

Prodinger, Birgit; Cieza, Alarcos; Oberhauser, Cornelia; Bickenbach, Jerome; Üstün, Tevfik Bedirhan; Chatterji, Somnath; Stucki, Gerold

2016-06-01

To develop a comprehensive set of the International Classification of Functioning, Disability and Health (ICF) categories as a minimal standard for reporting and assessing functioning and disability in clinical populations along the continuum of care. The specific aims were to specify the domains of functioning recommended for an ICF Rehabilitation Set and to identify a minimal set of environmental factors (EFs) to be used alongside the ICF Rehabilitation Set when describing disability across individuals and populations with various health conditions. Secondary analysis of existing data sets using regression methods (Random Forests and Group Lasso regression) and expert consultations. Along the continuum of care, including acute, early postacute, and long-term and community rehabilitation settings. Persons (N=9863) with various health conditions participated in primary studies. The number of respondents for whom the dependent variable data were available and used in this analysis was 9264. Not applicable. For regression analyses, self-reported general health was used as a dependent variable. The ICF categories from the functioning component and the EF component were used as independent variables for the development of the ICF Rehabilitation Set and the minimal set of EFs, respectively. Thirty ICF categories to be complemented with 12 EFs were identified as relevant to the identified ICF sets. The ICF Rehabilitation Set constitutes of 9 ICF categories from the component body functions and 21 from the component activities and participation. The minimal set of EFs contains 12 categories spanning all chapters of the EF component of the ICF. The identified sets proposed serve as minimal generic sets of aspects of functioning in clinical populations for reporting data within and across heath conditions, time, clinical settings including rehabilitation, and countries. These sets present a reference framework for harmonizing existing information on disability across general and clinical populations. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Drinking and smoking patterns during pregnancy: Development of group-based trajectories in the Safe Passage Study.

PubMed

Dukes, Kimberly; Tripp, Tara; Willinger, Marian; Odendaal, Hein; Elliott, Amy J; Kinney, Hannah C; Robinson, Fay; Petersen, Julie M; Raffo, Cheryl; Hereld, Dale; Groenewald, Coen; Angal, Jyoti; Hankins, Gary; Burd, Larry; Fifer, William P; Myers, Michael M; Hoffman, Howard J; Sullivan, Lisa

2017-08-01

Precise identification of drinking and smoking patterns during pregnancy is crucial to better understand the risk to the fetus. The purpose of this manuscript is to describe the methodological approach used to define prenatal drinking and smoking trajectories from a large prospective pregnancy cohort, and to describe maternal characteristics associated with different exposure patterns. In the Safe Passage Study, detailed information regarding quantity, frequency, and timing of exposure was self-reported up to four times during pregnancy and at 1 month post-delivery. Exposure trajectories were developed using data from 11,692 pregnancies (9912 women) where pregnancy outcome was known. Women were from three diverse populations: white (23%) and American Indian (17%) in the Northern Plains, US, and mixed ancestry (59%) in South Africa (other/not specified [1%]). Group-based trajectory modeling was used to identify 5 unique drinking trajectories (1 none/minimal, 2 quitting groups, 2 continuous groups) and 7 smoking trajectories (1 none/minimal, 2 quitting groups, 4 continuous groups). Women with pregnancies assigned to the low- or high-continuous drinking groups were less likely to have completed high school and were more likely to have enrolled in the study in the third trimester, be of mixed ancestry, or be depressed than those assigned to the none/minimal or quit-drinking groups. Results were similar when comparing continuous smokers to none/minimal and quit-smoking groups. Further, women classified as high- or low-continuous drinkers were more likely to smoke at moderate-, high-, and very high-continuous levels, as compared to women classified as non-drinkers and quitters. This is the first study of this size to utilize group-based trajectory modeling to identify unique prenatal drinking and smoking trajectories. These trajectories will be used in future analyses to determine which specific exposure patterns subsequently manifest as poor peri- and postnatal outcomes. Copyright © 2017 Elsevier Inc. All rights reserved.

The paradox of cooling streams in a warming world: Regional climate trends do not parallel variable local trends in stream temperature in the Pacific continental United States

USGS Publications Warehouse

Arismendi, Ivan; Johnson, Sherri; Dunham, Jason B.; Haggerty, Roy; Hockman-Wert, David

2012-01-01

Temperature is a fundamentally important driver of ecosystem processes in streams. Recent warming of terrestrial climates around the globe has motivated concern about consequent increases in stream temperature. More specifically, observed trends of increasing air temperature and declining stream flow are widely believed to result in corresponding increases in stream temperature. Here, we examined the evidence for this using long-term stream temperature data from minimally and highly human-impacted sites located across the Pacific continental United States. Based on hypothesized climate impacts, we predicted that we should find warming trends in the maximum, mean and minimum temperatures, as well as increasing variability over time. These predictions were not fully realized. Warming trends were most prevalent in a small subset of locations with longer time series beginning in the 1950s. More recent series of observations (1987-2009) exhibited fewer warming trends and more cooling trends in both minimally and highly human-influenced systems. Trends in variability were much less evident, regardless of the length of time series. Based on these findings, we conclude that our perspective of climate impacts on stream temperatures is clouded considerably by a lack of long-termdata on minimally impacted streams, and biased spatio-temporal representation of existing time series. Overall our results highlight the need to develop more mechanistic, process-based understanding of linkages between climate change, other human impacts and stream temperature, and to deploy sensor networks that will provide better information on trends in stream temperatures in the future.

Visual resource inventory and Imnaha Valley study: Hells Canyon National Recreation Area

Treesearch

David H. Blau; Michael C. Bowie; Frank Hunsaker

1979-01-01

Hells Canyon National Recreation Area was established by an Act of Congress in December 1975. At that time, the U.S. Forest Service, which administers most of the land included, was given the responsibility of developing a Comprehensive Management Plan for the NRA within five years. In order to minimize future visual degradation, the Forest Service planning team for...

Reasoning, Not Recipes: Helping Your Students Develop Statistical Understanding and Enjoy the Experience!

ERIC Educational Resources Information Center

Mooney, Gai

2010-01-01

Statistics is often presented to students as a series of algorithms to be learnt by heart and applied at the appropriate time to get "the correct answer". This approach, while it may in fact produce the right answer, has been shown to be minimally effective at helping students understand the underlying statistical concepts. As Holmes noted,…

A Study of Criteria for the Evaluation of Secondary School Instrumentalists When Auditioning for Festival Bands. Final Report.

ERIC Educational Resources Information Center

Owen, Curtis D., Jr.

This study purposed to develop a means of evaluating student performance in auditions for festival bands which would minimize the inconsistencies of subjective judgment. Tape recordings of student auditions were played three times to judges. During the first audition, evaluators rated students on a continuum scale with numerical divisions, and…

Work Climate, Organizational Commitment, and Highway Safety in the Trucking Industry: Toward Causal Modeling of Large Truck Crashes

ERIC Educational Resources Information Center

Graham, Carroll M.; Scott, Aaron J.; Nafukho, Fredrick M.

2008-01-01

While theoretical models aimed at explaining or predicting employee turnover outcomes have been developed, minimal consideration has been given to the same task regarding safety, often measured as the probability of a crash in a given time frame. The present literature review identifies four constructs from turnover literature, which are believed…

Advanced X-Ray Timing Array Mission: Conceptual Spacecraft Design Study

NASA Technical Reports Server (NTRS)

Hopkins, R. C.; Johnson, L.; Thomas, H. D.; Wilson-Hodge, C. A.; Baysinger, M.; Maples, C. D.; Fabisinski, L.L.; Hornsby, L.; Thompson, K. S.; Miernik, J. H.

2011-01-01

The Advanced X-Ray Timing Array (AXTAR) is a mission concept for submillisecond timing of bright galactic x-ray sources. The two science instruments are the Large Area Timing Array (LATA) (a collimated instrument with 2-50-keV coverage and over 3 square meters of effective area) and a Sky Monitor (SM), which acts as a trigger for pointed observations of x-ray transients. The spacecraft conceptual design team developed two spacecraft concepts that will enable the AXTAR mission: A minimal configuration to be launched on a Taurus II and a larger configuration to be launched on a Falcon 9 or similar vehicle.

Comparing fixed sampling with minimizer sampling when using k-mer indexes to find maximal exact matches.

PubMed

Almutairy, Meznah; Torng, Eric

2018-01-01

Bioinformatics applications and pipelines increasingly use k-mer indexes to search for similar sequences. The major problem with k-mer indexes is that they require lots of memory. Sampling is often used to reduce index size and query time. Most applications use one of two major types of sampling: fixed sampling and minimizer sampling. It is well known that fixed sampling will produce a smaller index, typically by roughly a factor of two, whereas it is generally assumed that minimizer sampling will produce faster query times since query k-mers can also be sampled. However, no direct comparison of fixed and minimizer sampling has been performed to verify these assumptions. We systematically compare fixed and minimizer sampling using the human genome as our database. We use the resulting k-mer indexes for fixed sampling and minimizer sampling to find all maximal exact matches between our database, the human genome, and three separate query sets, the mouse genome, the chimp genome, and an NGS data set. We reach the following conclusions. First, using larger k-mers reduces query time for both fixed sampling and minimizer sampling at a cost of requiring more space. If we use the same k-mer size for both methods, fixed sampling requires typically half as much space whereas minimizer sampling processes queries only slightly faster. If we are allowed to use any k-mer size for each method, then we can choose a k-mer size such that fixed sampling both uses less space and processes queries faster than minimizer sampling. The reason is that although minimizer sampling is able to sample query k-mers, the number of shared k-mer occurrences that must be processed is much larger for minimizer sampling than fixed sampling. In conclusion, we argue that for any application where each shared k-mer occurrence must be processed, fixed sampling is the right sampling method.

Comparing fixed sampling with minimizer sampling when using k-mer indexes to find maximal exact matches

PubMed Central

Torng, Eric

2018-01-01

Bioinformatics applications and pipelines increasingly use k-mer indexes to search for similar sequences. The major problem with k-mer indexes is that they require lots of memory. Sampling is often used to reduce index size and query time. Most applications use one of two major types of sampling: fixed sampling and minimizer sampling. It is well known that fixed sampling will produce a smaller index, typically by roughly a factor of two, whereas it is generally assumed that minimizer sampling will produce faster query times since query k-mers can also be sampled. However, no direct comparison of fixed and minimizer sampling has been performed to verify these assumptions. We systematically compare fixed and minimizer sampling using the human genome as our database. We use the resulting k-mer indexes for fixed sampling and minimizer sampling to find all maximal exact matches between our database, the human genome, and three separate query sets, the mouse genome, the chimp genome, and an NGS data set. We reach the following conclusions. First, using larger k-mers reduces query time for both fixed sampling and minimizer sampling at a cost of requiring more space. If we use the same k-mer size for both methods, fixed sampling requires typically half as much space whereas minimizer sampling processes queries only slightly faster. If we are allowed to use any k-mer size for each method, then we can choose a k-mer size such that fixed sampling both uses less space and processes queries faster than minimizer sampling. The reason is that although minimizer sampling is able to sample query k-mers, the number of shared k-mer occurrences that must be processed is much larger for minimizer sampling than fixed sampling. In conclusion, we argue that for any application where each shared k-mer occurrence must be processed, fixed sampling is the right sampling method. PMID:29389989

The Use of Prototypes in Weapon System Development

DTIC Science & Technology

1981-03-01

engine to minimize flameouts; experience showed that some uses of composite mate- rials were unwarranted, and other uses were proved valid; and a special... composite structure materials. The YF-16 used a single F100, an engine already developed for the F-15 program. By the time of the YF-16 first flight...lessons learned during the prototype tests led to a reduction in the use of composite materials ir the full scale F-16A program. UTTAS. Because of the

Food Acquisition: Food Ingredients, Raw Materials and Supply

NASA Technical Reports Server (NTRS)

Wheat, D. W.

1984-01-01

The kind of food supply system that will serve the space station in coming years is considered. The direction and rate of evolution of space food service systems is also considered and what is needed to supply appropriate food to space station crews. Innovations in food sourcing, recipe development, pre-preparation, packaging, preservation, presentation, consumption and waste disposal are discussed. The development and validation of preparation systems and ingredients which minimize demands on crew time and provide maximum eating enjoyment is outlined.

Experience in Construction and Operation of the Distributed Information Systems on the Basis of the Z39.50 Protocol

NASA Astrophysics Data System (ADS)

Zhizhimov, Oleg; Mazov, Nikolay; Skibin, Sergey

Questions concerned with construction and operation of the distributed information systems on the basis of ANSI/NISO Z39.50 Information Retrieval Protocol are discussed in the paper. The paper is based on authors' practice in developing ZooPARK server. Architecture of distributed information systems, questions of reliability of such systems, minimization of search time and administration are examined. Problems with developing of distributed information systems are also described.

Mobile and Wireless Technologies in Health Behavior and the Potential for Intensively Adaptive Interventions.

PubMed

Riley, William T; Serrano, Katrina J; Nilsen, Wendy; Atienza, Audie A

2015-10-01

Recent advances in mobile and wireless technologies have made real-time assessments of health behaviors and their influences possible with minimal respondent burden. These tech-enabled real-time assessments provide the basis for intensively adaptive interventions (IAIs). Evidence of such studies that adjust interventions based on real-time inputs is beginning to emerge. Although IAIs are promising, the development of intensively adaptive algorithms generate new research questions, and the intensive longitudinal data produced by IAIs require new methodologies and analytic approaches. Research considerations and future directions for IAIs in health behavior research are provided.

[Pharmaceutical logistic in turnover of pharmaceutical products of Azerbaijan].

PubMed

Dzhalilova, K I

2009-11-01

Development of pharmaceutical logistic system model promotes optimal strategy for pharmaceutical functioning. The goal of such systems is organization of pharmaceutical product's turnover in required quantity and assortment, at preset time and place, at a highest possible degree of consumption readiness with minimal expenses and qualitative service. Organization of the optimal turnover chain in the region is offered to start from approximate classification of medicaments by logistic characteristics. Supplier selection was performed by evaluation of timeliness of delivery, quality of delivered products (according to the minimum acceptable level of quality) and time-keeping of time spending for orders delivery.

Shape Sensing Techniques for Continuum Robots in Minimally Invasive Surgery: A Survey.

PubMed

Shi, Chaoyang; Luo, Xiongbiao; Qi, Peng; Li, Tianliang; Song, Shuang; Najdovski, Zoran; Fukuda, Toshio; Ren, Hongliang

2017-08-01

Continuum robots provide inherent structural compliance with high dexterity to access the surgical target sites along tortuous anatomical paths under constrained environments and enable to perform complex and delicate operations through small incisions in minimally invasive surgery. These advantages enable their broad applications with minimal trauma and make challenging clinical procedures possible with miniaturized instrumentation and high curvilinear access capabilities. However, their inherent deformable designs make it difficult to realize 3-D intraoperative real-time shape sensing to accurately model their shape. Solutions to this limitation can lead themselves to further develop closely associated techniques of closed-loop control, path planning, human-robot interaction, and surgical manipulation safety concerns in minimally invasive surgery. Although extensive model-based research that relies on kinematics and mechanics has been performed, accurate shape sensing of continuum robots remains challenging, particularly in cases of unknown and dynamic payloads. This survey investigates the recent advances in alternative emerging techniques for 3-D shape sensing in this field and focuses on the following categories: fiber-optic-sensor-based, electromagnetic-tracking-based, and intraoperative imaging modality-based shape-reconstruction methods. The limitations of existing technologies and prospects of new technologies are also discussed.

Sparse reconstruction of breast MRI using homotopic L0 minimization in a regional sparsified domain.

PubMed

Wong, Alexander; Mishra, Akshaya; Fieguth, Paul; Clausi, David A

2013-03-01

The use of MRI for early breast examination and screening of asymptomatic women has become increasing popular, given its ability to provide detailed tissue characteristics that cannot be obtained using other imaging modalities such as mammography and ultrasound. Recent application-oriented developments in compressed sensing theory have shown that certain types of magnetic resonance images are inherently sparse in particular transform domains, and as such can be reconstructed with a high level of accuracy from highly undersampled k-space data below Nyquist sampling rates using homotopic L0 minimization schemes, which holds great potential for significantly reducing acquisition time. An important consideration in the use of such homotopic L0 minimization schemes is the choice of sparsifying transform. In this paper, a regional differential sparsifying transform is investigated for use within a homotopic L0 minimization framework for reconstructing breast MRI. By taking local regional characteristics into account, the regional differential sparsifying transform can better account for signal variations and fine details that are characteristic of breast MRI than the popular finite differential transform, while still maintaining strong structure fidelity. Experimental results show that good breast MRI reconstruction accuracy can be achieved compared to existing methods.

Application of Sequential Quadratic Programming to Minimize Smart Active Flap Rotor Hub Loads

NASA Technical Reports Server (NTRS)

Kottapalli, Sesi; Leyland, Jane

2014-01-01

In an analytical study, SMART active flap rotor hub loads have been minimized using nonlinear programming constrained optimization methodology. The recently developed NLPQLP system (Schittkowski, 2010) that employs Sequential Quadratic Programming (SQP) as its core algorithm was embedded into a driver code (NLP10x10) specifically designed to minimize active flap rotor hub loads (Leyland, 2014). Three types of practical constraints on the flap deflections have been considered. To validate the current application, two other optimization methods have been used: i) the standard, linear unconstrained method, and ii) the nonlinear Generalized Reduced Gradient (GRG) method with constraints. The new software code NLP10x10 has been systematically checked out. It has been verified that NLP10x10 is functioning as desired. The following are briefly covered in this paper: relevant optimization theory; implementation of the capability of minimizing a metric of all, or a subset, of the hub loads as well as the capability of using all, or a subset, of the flap harmonics; and finally, solutions for the SMART rotor. The eventual goal is to implement NLP10x10 in a real-time wind tunnel environment.

[Total hip arthroplasty through anterior "minimal invasive" approach].

PubMed

Moerenhout, Kevin G; Cherix, Stéphane; Rüdiger, Hannes A

2012-12-19

Total hip replacement has seen a tremendous development and has become one of the most successful surgical interventions in orthopaedics. While during the first decades of development of total hip arthroplasty the fixation of the implant into the bone was the main concern, the focus has shifted towards surgical technique and soft tissue handling. In order to avoid permanent soft tissue damage, muscular dysfunction and concerns in regards to cosmetics, minimal invasive and anatomic approaches have been developed. We here provide a short overview on various methods of total hip replacements and we describe our technique through a minimal invasive direct anterior approach. While muscle and nerve damage is minimal, this technique allows for a rapid rehabilitation and is associated with an excellent functional outcome and a minimal risk for dislocation.

Shape Memory Silk Protein Sponges for Minimally Invasive Tissue Regeneration.

PubMed

Brown, Joseph E; Moreau, Jodie E; Berman, Alison M; McSherry, Heather J; Coburn, Jeannine M; Schmidt, Daniel F; Kaplan, David L

2017-01-01

Porous silk protein scaffolds are designed to display shape memory characteristics and volumetric recovery following compression. Two strategies are utilized to realize shape recovery: addition of hygroscopic plasticizers like glycerol, and tyrosine modifications with hydrophilic sulfonic acid chemistries. Silk sponges are evaluated for recovery following 80% compressive strain, total porosity, pore size distribution, secondary structure development, in vivo volume retention, cell infiltration, and inflammatory responses. Glycerol-modified sponges recover up to 98.3% of their original dimensions following compression, while sulfonic acid/glycerol modified sponges swell in water up to 71 times their compressed volume, well in excess of their original size. Longer silk extraction times (lower silk molecular weights) and higher glycerol concentrations yielded greater flexibility and shape fidelity, with no loss in modulus following compression. Sponges are over 95% porous, with secondary structure analysis indicating glycerol-induced β-sheet physical crosslinking. Tyrosine modifications with sulfonic acid interfere with β-sheet formation. Glycerol-modified sponges exhibit improved rates of cellular infiltration at subcutaneous implant sites with minimal immune response in mice. They also degrade more rapidly than unmodified sponges, a result posited to be cell-mediated. Overall, this work suggests that silk sponges may be useful for minimally invasive deployment in soft tissue augmentation procedures. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Manipulation and handling processes off-line programming and optimization with use of K-Roset

NASA Astrophysics Data System (ADS)

Gołda, G.; Kampa, A.

2017-08-01

Contemporary trends in development of efficient, flexible manufacturing systems require practical implementation of modern “Lean production” concepts for maximizing customer value through minimizing all wastes in manufacturing and logistics processes. Every FMS is built on the basis of automated and robotized production cells. Except flexible CNC machine tools and other equipments, the industrial robots are primary elements of the system. In the studies, authors look for wastes of time and cost in real tasks of robots, during manipulation processes. According to aspiration for optimization of handling and manipulation processes with use of the robots, the application of modern off-line programming methods and computer simulation, is the best solution and it is only way to minimize unnecessary movements and other instructions. The modelling process of robotized production cell and offline programming of Kawasaki robots in AS-Language will be described. The simulation of robotized workstation will be realized with use of virtual reality software K-Roset. Authors show the process of industrial robot’s programs improvement and optimization in terms of minimizing the number of useless manipulator movements and unnecessary instructions. This is realized in order to shorten the time of production cycles. This will also reduce costs of handling, manipulations and technological process.

Technology advances in hospital practices: robotics in treatment of patients.

PubMed

Rosiek, Anna; Leksowski, Krzysztof

2015-06-01

Laparoscopic cholecystectomy is widely considered as the treatment of choice for acute cholecystitis. The safety of the procedure and its minimal invasiveness made it a valid treatment option for a patient not responding to antibiotic therapy. Our research shows that patients positively assess this treatment method, but the world's tendency is to turn to a more sophisticated method utilizing robot-assisted surgery as a gold standard. Providing patient with minimally invasive surgical procedures that utilize the state-of-the-art equipment like the da Vinci Robotic Surgical System underscores the commitment to high-quality patient care while enhancing patient safety. The advantages include minimal invasive scarring, less pain and bleeding, faster recovery time, and shorter hospital stay. The move toward less invasive and less morbid procedures and a need to re-create the true open surgical experience have paved the way for the development and application of robotic and computer-assisted systems in surgery in Poland as well as the rest of the world. © The Author(s) 2014.

Minimizing target interference in PK immunoassays: new approaches for low-pH-sample treatment.

PubMed

Partridge, Michael A; Pham, John; Dziadiv, Olena; Luong, Onson; Rafique, Ashique; Sumner, Giane; Torri, Albert

2013-08-01

Quantitating total levels of monoclonal antibody (mAb) biotherapeutics in serum using ELISA may be hindered by soluble targets. We developed two low-pH-sample-pretreatment techniques to minimize target interference. The first procedure involves sample pretreatment at pH <3.0 before neutralization and analysis in a target capture ELISA. Careful monitoring of acidification time is required to minimize potential impact on mAb detection. The second approach involves sample dilution into mild acid (pH ∼4.5) before transferring to an anti-human capture-antibody-coated plate without neutralization. Analysis of target-drug and drug-capture antibody interactions at pH 4.5 indicated that the capture antibody binds to the drug, while the drug and the target were dissociated. Using these procedures, total biotherapeutic levels were accurately measured when soluble target was >30-fold molar excess. These techniques provide alternatives for quantitating mAb biotherapeutics in the presence of a target when standard acid-dissociation procedures are ineffective.

Preliminary study on enhancing waste management best practice model in Malaysia construction industry

NASA Astrophysics Data System (ADS)

Jamaludin, Amril Hadri; Karim, Nurulzatushima Abdul; Noor, Raja Nor Husna Raja Mohd; Othman, Nurulhidayah; Malik, Sulaiman Abdul

2017-08-01

Construction waste management (CWM) is the practice of minimizing and diverting construction waste, demolition debris, and land-clearing debris from disposal and redirecting recyclable resources back into the construction process. Best practice model means best choice from the collection of other practices that was built for purpose of construction waste management. The practice model can help the contractors in minimizing waste before the construction activities will be started. The importance of minimizing wastage will have direct impact on time, cost and quality of a construction project. This paper is focusing on the preliminary study to determine the factors of waste generation in the construction sites and identify the effectiveness of existing construction waste management practice conducted in Malaysia. The paper will also include the preliminary works of planned research location, data collection method, and analysis to be done by using the Analytical Hierarchy Process (AHP) to help in developing suitable waste management best practice model that can be used in the country.

Tachyon field non-minimally coupled to massive neutrino matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahmad, Safia; Myrzakulov, Nurgissa; Myrzakulov, R., E-mail: safia@ctp-jamia.res.in, E-mail: nmyrzakulov@gmail.com, E-mail: rmyrzakulov@gmail.com

2016-07-01

In this paper, we consider rolling tachyon, with steep run-away type of potentials non-minimally coupled to massive neutrino matter. The coupling dynamically builds up at late times as neutrino matter turns non-relativistic. In case of scaling and string inspired potentials, we have shown that non-minimal coupling leads to minimum in the field potential. Given a suitable choice of model parameters, it is shown to give rise to late-time acceleration with the desired equation of state.

Voltage scheduling for low power/energy

NASA Astrophysics Data System (ADS)

Manzak, Ali

2001-07-01

Power considerations have become an increasingly dominant factor in the design of both portable and desk-top systems. An effective way to reduce power consumption is to lower the supply voltage since voltage is quadratically related to power. This dissertation considers the problem of lowering the supply voltage at (i) the system level and at (ii) the behavioral level. At the system level, the voltage of the variable voltage processor is dynamically changed with the work load. Processors with limited sized buffers as well as those with very large buffers are considered. Given the task arrival times, deadline times, execution times, periods and switching activities, task scheduling algorithms that minimize energy or peak power are developed for the processors equipped with very large buffers. A relation between the operating voltages of the tasks for minimum energy/power is determined using the Lagrange multiplier method, and an iterative algorithm that utilizes this relation is developed. Experimental results show that the voltage assignment obtained by the proposed algorithm is very close (0.1% error) to that of the optimal energy assignment and the optimal peak power (1% error) assignment. Next, on-line and off-fine minimum energy task scheduling algorithms are developed for processors with limited sized buffers. These algorithms have polynomial time complexity and present optimal (off-line) and close-to-optimal (on-line) solutions. A procedure to calculate the minimum buffer size given information about the size of the task (maximum, minimum), execution time (best case, worst case) and deadlines is also presented. At the behavioral level, resources operating at multiple voltages are used to minimize power while maintaining the throughput. Such a scheme has the advantage of allowing modules on the critical paths to be assigned to the highest voltage levels (thus meeting the required timing constraints) while allowing modules on non-critical paths to be assigned to lower voltage levels (thus reducing the power consumption). A polynomial time resource and latency constrained scheduling algorithm is developed to distribute the available slack among the nodes such that power consumption is minimum. The algorithm is iterative and utilizes the slack based on the Lagrange multiplier method.

Evaluation of the Turkish translation of the Minimal Standard Terminology for Digestive Endoscopy by development of an endoscopic information system.

PubMed

Atalağ, Koray; Bilgen, Semih; Gür, Gürden; Boyacioğlu, Sedat

2007-09-01

There are very few evaluation studies for the Minimal Standard Terminology for Digestive Endoscopy. This study aims to evaluate the usage of the Turkish translation of Minimal Standard Terminology by developing an endoscopic information system. After elicitation of requirements, database modeling and software development were performed. Minimal Standard Terminology driven forms were designed for rapid data entry. The endoscopic report was rapidly created by applying basic Turkish syntax and grammar rules. Entering free text and also editing of final report were possible. After three years of live usage, data analysis was performed and results were evaluated. The system has been used for reporting of all endoscopic examinations. 15,638 valid records were analyzed, including 11,381 esophagogastroduodenoscopies, 2,616 colonoscopies, 1,079 rectoscopies and 562 endoscopic retrograde cholangiopancreatographies. In accordance with other previous validation studies, the overall usage of Minimal Standard Terminology terms was very high: 85% for examination characteristics, 94% for endoscopic findings and 94% for endoscopic diagnoses. Some new terms, attributes and allowed values were also added for better clinical coverage. Minimal Standard Terminology has been shown to cover a high proportion of routine endoscopy reports. Good user acceptance proves that both the terms and structure of Minimal Standard Terminology were consistent with usual clinical thinking. However, future work on Minimal Standard Terminology is mandatory for better coverage of endoscopic retrograde cholangiopancreatographies examinations. Technically new software development methodologies have to be sought for lowering cost of development and the maintenance phase. They should also address integration and interoperability of disparate information systems.

Robotics-based synthesis of human motion.

PubMed

Khatib, O; Demircan, E; De Sapio, V; Sentis, L; Besier, T; Delp, S

2009-01-01

The synthesis of human motion is a complex procedure that involves accurate reconstruction of movement sequences, modeling of musculoskeletal kinematics, dynamics and actuation, and characterization of reliable performance criteria. Many of these processes have much in common with the problems found in robotics research. Task-based methods used in robotics may be leveraged to provide novel musculoskeletal modeling methods and physiologically accurate performance predictions. In this paper, we present (i) a new method for the real-time reconstruction of human motion trajectories using direct marker tracking, (ii) a task-driven muscular effort minimization criterion and (iii) new human performance metrics for dynamic characterization of athletic skills. Dynamic motion reconstruction is achieved through the control of a simulated human model to follow the captured marker trajectories in real-time. The operational space control and real-time simulation provide human dynamics at any configuration of the performance. A new criteria of muscular effort minimization has been introduced to analyze human static postures. Extensive motion capture experiments were conducted to validate the new minimization criterion. Finally, new human performance metrics were introduced to study in details an athletic skill. These metrics include the effort expenditure and the feasible set of operational space accelerations during the performance of the skill. The dynamic characterization takes into account skeletal kinematics as well as muscle routing kinematics and force generating capacities. The developments draw upon an advanced musculoskeletal modeling platform and a task-oriented framework for the effective integration of biomechanics and robotics methods.

Minimal evolution time and quantum speed limit of non-Markovian open systems

PubMed Central

Meng, Xiangyi; Wu, Chengjun; Guo, Hong

2015-01-01

We derive a sharp bound as the quantum speed limit (QSL) for the minimal evolution time of quantum open systems in the non-Markovian strong-coupling regime with initial mixed states by considering the effects of both renormalized Hamiltonian and dissipator. For a non-Markovian quantum open system, the possible evolution time between two arbitrary states is not unique, among the set of which we find that the minimal one and its QSL can decrease more steeply by adjusting the coupling strength of the dissipator, which thus provides potential improvements of efficiency in many quantum physics and quantum information areas. PMID:26565062

Minimum-Time and Vibration Avoidance Attitude Maneuver for Spacecraft with Torque and Momentum Limit Constraints in Redundant Reaction Wheel Configuration

NASA Technical Reports Server (NTRS)

Ha, Kong Q.; Femiano, Michael D.; Mosier, Gary E.

2004-01-01

In this paper, we present an optimal open-loop slew trajectory algorithm developed at GSFC for the so-called "Yardstick design" of the James Webb Space Telescope (JWST). JWST is an orbiting infrared observatory featuring a lightweight, segmented primary mirror approximately 6 meters in diameter and a sunshield approximately the size of a tennis court. This large, flexible structure will have significant number of lightly damped, dominant flexible modes. With very stringent requirements on pointing accuracy and image quality, it is important that slewing be done within the required time constraint and with minimal induced vibration in order to maximize observing efficiency. With reaction wheels as control actuators, initial wheel speeds as well as individual wheel torque and momentum limits become dominant constraints in slew performance. These constraints must be taken into account when performing slews to ensure that unexpected reaction wheel saturation does not occur, since such saturation leads to control failure in accurately tracking commanded motion and produces high frequency torque components capable of exciting structural modes. A minimum-time constraint is also included and coupled with reaction wheel limit constraints in the optimization to minimize both the effect of the control torque on the flexible body motion and the maneuver time. The optimization is on slew command parameters, such as maximum slew velocity and acceleration, for a given redundant reaction wheel configuration and is based on the dynamic interaction between the spacecraft and reaction wheel motion. Analytical development of the slew algorithm to generate desired slew position, rate, and acceleration profiles to command a feedback/feed forward control system is described. High-fidelity simulation and experimental results are presented to show that the developed slew law achieves the objectives.

Intramedullary compression arthrodesis of the knee: early experience with a new device and technique.

PubMed

McQueen, David A; Cooke, Francis W; Hahn, Dustan L

2005-01-01

The irretrievably failed total knee arthroplasty is the primary indication for knee arthrodesis. Because this difficult condition is relatively rare, an intramedullary arthrodesis system was developed which requires minimal surgeon experience for successful use. The new system called the Wichita Fusion Nail was implanted by a single surgeon in 13 consecutive patients: 11 for arthrodesis alone, 1 for stabilization of a supracondylar fracture nonunion, and 1 for arthrodesis coupled with a supracondylar fracture nonunion. All arthrodesis attempts were successful. The average fusion time was 15.2 weeks except for 2 infected delayed arthrodeses. Both fracture nonunions persisted and went on to amputation. The WFN provides a simple arthrodesis system with minimal technique dependence and a high potential for success.

Traffic routing for multicomputer networks with virtual cut-through capability

NASA Technical Reports Server (NTRS)

Kandlur, Dilip D.; Shin, Kang G.

1992-01-01

Consideration is given to the problem of selecting routes for interprocess communication in a network with virtual cut-through capability, while balancing the network load and minimizing the number of times that a message gets buffered. An approach is proposed that formulates the route selection problem as a minimization problem with a link cost function that depends upon the traffic through the link. The form of this cost function is derived using the probability of establishing a virtual cut-through route. The route selection problem is shown to be NP-hard, and an algorithm is developed to incrementally reduce the cost by rerouting the traffic. The performance of this algorithm is exemplified by two network topologies: the hypercube and the C-wrapped hexagonal mesh.

Robotic transgastric cystgastrostomy and pancreatic debridement in the management of pancreatic fluid collections following acute pancreatitis.

PubMed

Kirks, Russell C; Sola, Richard; Iannitti, David A; Martinie, John B; Vrochides, Dionisios

2016-01-01

Pancreatic and peripancreatic fluid collections may develop after severe acute pancreatitis. Organized fluid collections such as pancreatic pseudocyst and walled-off pancreatic necrosis (WOPN) that mature over time may require intervention to treat obstructive or constitutional symptoms related to the size and location of the collection as well as possible infection. Endoscopic, open surgical and minimally invasive techniques are described to treat post-inflammatory pancreatic fluid collections. Surgical intervention may be required to treat collections containing necrotic pancreatic parenchyma or in locations not immediately apposed to the stomach or duodenum. Comprising a blend of the surgical approach and the clinical benefits of minimally invasive surgery, the robot-assisted technique of pancreatic cystgastrostomy with pancreatic debridement is described.

Interacting vector fields in relativity without relativity

NASA Astrophysics Data System (ADS)

Anderson, Edward; Barbour, Julian

2002-06-01

Barbour, Foster and Ó Murchadha have recently developed a new framework, called here the 3-space approach, for the formulation of classical bosonic dynamics. Neither time nor a locally Minkowskian structure of spacetime are presupposed. Both arise as emergent features of the world from geodesic-type dynamics on a space of three-dimensional metric-matter configurations. In fact gravity, the universal light-cone and Abelian gauge theory minimally coupled to gravity all arise naturally through a single common mechanism. It yields relativity - and more - without presupposing relativity. This paper completes the recovery of the presently known bosonic sector within the 3-space approach. We show, for a rather general ansatz, that 3-vector fields can interact among themselves only as Yang-Mills fields minimally coupled to gravity.

Future Visions for Scientific Human Exploration

NASA Technical Reports Server (NTRS)

Garvin, James

2005-01-01

Today, humans explore deep-space locations such as Mars, asteroids, and beyond, vicariously here on Earth, with noteworthy success. However, to achieve the revolutionary breakthroughs that have punctuated the history of science since the dawn of the Space Age has always required humans as "the discoverers," as Daniel Boorstin contends in this book of the same name. During Apollo 17, human explorers on the lunar surface discovered the "genesis rock," orange glass, and humans in space revamped the optically crippled Hubble Space Telescope to enable some of the greatest astronomical discoveries of all time. Science-driven human exploration is about developing the opportunities for such events, perhaps associated with challenging problems such as whether we can identify life beyond Earth within the universe. At issue, however, is how to safely insert humans and the spaceflight systems required to allow humans to operate as they do best in the hostile environment of deep space. The first issue is minimizing the problems associated with human adaptation to the most challenging aspects of deep space space radiation and microgravity (or non-Earth gravity). One solution path is to develop technologies that allow for minimization of the exposure time of people to deep space, as was accomplished in Apollo. For a mission to the planet Mars, this might entail new technological solutions for in-space propulsion that would make possible time-minimized transfers to and from Mars. The problem of rapid, reliable in-space transportation is challenged by the celestial mechanics of moving in space and the so-called "rocket equation." To travel to Mars from Earth in less than the time fuel-minimizing trajectories allow (i.e., Hohmann transfers) requires an exponential increase in the amount of fuel. Thus, month-long transits would require a mass of fuel as large as the dry mass of the ISS, assuming the existence of continuous acceleration engines. This raises the largest technological stumbling block to moving humans on site as deep-space explorers, delivering the masses required for human spaceflight systems to LEO or other Earth orbital vantage points using the existing or projected fleet of Earth-to-orbit (ETO) launch vehicles. Without a return to Saturn V-class boosters or an alternate path, one cannot imagine emplacing the masses that would be required for any deep-space voyage without a prohibitive number of Shuttle-class launches. One futurist solution might involve mass launch systems that could be used to move the consumables, including fuel, water, food, and building materials, to LEO in pieces rather than launching integrated systems. This approach would necessitate the development of robotic assembly and fuel-storage systems in Earth orbit, but could provide for a natural separation of low-value cargo (e.g., fuel, water).

Development Cycle Time Simulation for Civil Aircraft

NASA Technical Reports Server (NTRS)

Spitz, William; Berardino, Frank; Golaszewski, Richard; Johnson, Jesse

2001-01-01

Cycle Time Reduction (CTR) will be one of the major factors affecting the future of the civil aerospace industry. This focus is the end reflection of the level of competition in the commercial large carrier aircraft industry. Aircraft manufacturer must minimize costs and pass a portion of those savings onto buyers. CTR is one strategy used to move the manufacturing firm down the cost curve. The current NASA Airframe Development Cycle Time Reduction Goal is 50% by year 2022. This goal is not achievable based on the program analysis done by the LMI/GRA team. This may mean that the current roster of NASA CTR programs needs to be reexamined or that the program technology progress factors, as determined by the NASA experts, were understated. Programs that duplicate the reductions of others should be replaced with non-duplicative programs. In addition, new programs targeting a specific part of the cycle can be developed.

Hardware for dynamic quantum computing.

PubMed

Ryan, Colm A; Johnson, Blake R; Ristè, Diego; Donovan, Brian; Ohki, Thomas A

2017-10-01

We describe the hardware, gateware, and software developed at Raytheon BBN Technologies for dynamic quantum information processing experiments on superconducting qubits. In dynamic experiments, real-time qubit state information is fed back or fed forward within a fraction of the qubits' coherence time to dynamically change the implemented sequence. The hardware presented here covers both control and readout of superconducting qubits. For readout, we created a custom signal processing gateware and software stack on commercial hardware to convert pulses in a heterodyne receiver into qubit state assignments with minimal latency, alongside data taking capability. For control, we developed custom hardware with gateware and software for pulse sequencing and steering information distribution that is capable of arbitrary control flow in a fraction of superconducting qubit coherence times. Both readout and control platforms make extensive use of field programmable gate arrays to enable tailored qubit control systems in a reconfigurable fabric suitable for iterative development.

Costs and benefits of different methods of esophagectomy for esophageal cancer.

PubMed

Yanasoot, Alongkorn; Yolsuriyanwong, Kamtorn; Ruangsin, Sakchai; Laohawiriyakamol, Supparerk; Sunpaweravong, Somkiat

2017-01-01

Background A minimally invasive approach to esophagectomy is being used increasingly, but concerns remain regarding the feasibility, safety, cost, and outcomes. We performed an analysis of the costs and benefits of minimally invasive, hybrid, and open esophagectomy approaches for esophageal cancer surgery. Methods The data of 83 consecutive patients who underwent a McKeown's esophagectomy at Prince of Songkla University Hospital between January 2008 and December 2014 were analyzed. Open esophagectomy was performed in 54 patients, minimally invasive esophagectomy in 13, and hybrid esophagectomy in 16. There were no differences in patient characteristics among the 3 groups Minimally invasive esophagectomy was undertaken via a thoracoscopic-laparoscopic approach, hybrid esophagectomy via a thoracoscopic-laparotomy approach, and open esophagectomy by a thoracotomy-laparotomy approach. Results Minimally invasive esophagectomy required a longer operative time than hybrid or open esophagectomy ( p = 0.02), but these patients reported less postoperative pain ( p = 0.01). There were no significant differences in blood loss, intensive care unit stay, hospital stay, or postoperative complications among the 3 groups. Minimally invasive esophagectomy incurred higher operative and surgical material costs than hybrid or open esophagectomy ( p = 0.01), but there were no significant differences in inpatient care and total hospital costs. Conclusion Minimally invasive esophagectomy resulted in the least postoperative pain but the greatest operative cost and longest operative time. Open esophagectomy was associated with the lowest operative cost and shortest operative time but the most postoperative pain. Hybrid esophagectomy had a shorter learning curve while sharing the advantages of minimally invasive esophagectomy.

Inhomogeneous Jacobi equation for minimal surfaces and perturbative change in holographic entanglement entropy

NASA Astrophysics Data System (ADS)

Ghosh, Avirup; Mishra, Rohit

2018-04-01

The change in holographic entanglement entropy (HEE) for small fluctuations about pure anti-de Sitter (AdS) is obtained by a perturbative expansion of the area functional in terms of the change in the bulk metric and the embedded extremal surface. However it is known that change in the embedding appears at second order or higher. It was shown that these changes in the embedding can be calculated in the 2 +1 dimensional case by solving a "generalized geodesic deviation equation." We generalize this result to arbitrary dimensions by deriving an inhomogeneous form of the Jacobi equation for minimal surfaces. The solutions of this equation map a minimal surface in a given space time to a minimal surface in a space time which is a perturbation over the initial space time. Using this we perturbatively calculate the changes in HEE up to second order for boosted black brane like perturbations over AdS4.

Application of computational fluid dynamics to the study of vortex flow control for the management of inlet distortion

NASA Technical Reports Server (NTRS)

Anderson, Bernhard H.; Gibb, James

1992-01-01

A study is presented to demonstrate that the Reduced Navier-Stokes code RNS3D can be employed effectively to develop a vortex generator installation that minimizes engine face circumferential distortion by controlling the development of secondary flow. The necessary computing times are small enough to show that similar studies are feasible within an analysis-design environment with all its constraints of costs and time. This study establishes the nature of the performance enhancements that can be realized with vortex flow control, and indicates a set of aerodynamic properties that can be utilized to arrive at a successful vortex generator installation design.

Spacelab Mission Implementation Cost Assessment (SMICA)

NASA Technical Reports Server (NTRS)

Guynes, B. V.

1984-01-01

A total savings of approximately 20 percent is attainable if: (1) mission management and ground processing schedules are compressed; (2) the equipping, staffing, and operating of the Payload Operations Control Center is revised, and (3) methods of working with experiment developers are changed. The development of a new mission implementation technique, which includes mission definition, experiment development, and mission integration/operations, is examined. The Payload Operations Control Center is to relocate and utilize new computer equipment to produce cost savings. Methods of reducing costs by minimizing the Spacelab and payload processing time during pre- and post-mission operation at KSC are analyzed. The changes required to reduce costs in the analytical integration process are studied. The influence of time, requirements accountability, and risk on costs is discussed. Recommendation for cost reductions developed by the Spacelab Mission Implementation Cost Assessment study are listed.

A new sparse optimization scheme for simultaneous beam angle and fluence map optimization in radiotherapy planning

NASA Astrophysics Data System (ADS)

Liu, Hongcheng; Dong, Peng; Xing, Lei

2017-08-01

{{\\ell }2,1} -minimization-based sparse optimization was employed to solve the beam angle optimization (BAO) in intensity-modulated radiation therapy (IMRT) planning. The technique approximates the exact BAO formulation with efficiently computable convex surrogates, leading to plans that are inferior to those attainable with recently proposed gradient-based greedy schemes. In this paper, we alleviate/reduce the nontrivial inconsistencies between the {{\\ell }2,1} -based formulations and the exact BAO model by proposing a new sparse optimization framework based on the most recent developments in group variable selection. We propose the incorporation of the group-folded concave penalty (gFCP) as a substitution to the {{\\ell }2,1} -minimization framework. The new formulation is then solved by a variation of an existing gradient method. The performance of the proposed scheme is evaluated by both plan quality and the computational efficiency using three IMRT cases: a coplanar prostate case, a coplanar head-and-neck case, and a noncoplanar liver case. Involved in the evaluation are two alternative schemes: the {{\\ell }2,1} -minimization approach and the gradient norm method (GNM). The gFCP-based scheme outperforms both counterpart approaches. In particular, gFCP generates better plans than those obtained using the {{\\ell }2,1} -minimization for all three cases with a comparable computation time. As compared to the GNM, the gFCP improves both the plan quality and computational efficiency. The proposed gFCP-based scheme provides a promising framework for BAO and promises to improve both planning time and plan quality.

A new sparse optimization scheme for simultaneous beam angle and fluence map optimization in radiotherapy planning.

PubMed

Liu, Hongcheng; Dong, Peng; Xing, Lei

2017-07-20

[Formula: see text]-minimization-based sparse optimization was employed to solve the beam angle optimization (BAO) in intensity-modulated radiation therapy (IMRT) planning. The technique approximates the exact BAO formulation with efficiently computable convex surrogates, leading to plans that are inferior to those attainable with recently proposed gradient-based greedy schemes. In this paper, we alleviate/reduce the nontrivial inconsistencies between the [Formula: see text]-based formulations and the exact BAO model by proposing a new sparse optimization framework based on the most recent developments in group variable selection. We propose the incorporation of the group-folded concave penalty (gFCP) as a substitution to the [Formula: see text]-minimization framework. The new formulation is then solved by a variation of an existing gradient method. The performance of the proposed scheme is evaluated by both plan quality and the computational efficiency using three IMRT cases: a coplanar prostate case, a coplanar head-and-neck case, and a noncoplanar liver case. Involved in the evaluation are two alternative schemes: the [Formula: see text]-minimization approach and the gradient norm method (GNM). The gFCP-based scheme outperforms both counterpart approaches. In particular, gFCP generates better plans than those obtained using the [Formula: see text]-minimization for all three cases with a comparable computation time. As compared to the GNM, the gFCP improves both the plan quality and computational efficiency. The proposed gFCP-based scheme provides a promising framework for BAO and promises to improve both planning time and plan quality.

Minimally invasive excision of gynaecomastia – a novel and effective surgical technique

PubMed Central

Qutob, O; Elahi, B; Garimella, V; Ihsan, N; Drew, PJ

2010-01-01

INTRODUCTION More aesthetically acceptable treatment options have been sought to minimise the morbidity associated with open surgery for gynaecomastia. This study investigated the use of a vacuum-assisted biopsy device (VABD) and liposuction to provide minimally invasive approach. PATIENTS AND METHODS Patients diagnosed with idiopathic benign gynaecomastia referred to the Breast Care Unit of Castle Hill Hospital between June 2002 and April 2007 and requesting surgical intervention underwent VABD excision and liposuction. All patients underwent thorough investigations to exclude any underlying cause for their gynaecomastia. The procedure was carried out by a single consultant surgeon with special interest in breast surgery. An 8-G mammotome probe was advanced through a 4-mm incision positioned in the corresponding anterior axillary line to excise the glandular disc. Liposuction was performed through the same incision. Incision wounds were closed with Steristrips. A pressure dressing was applied over wound by corset and an inflatable device. RESULTS Thirty-six male patients with grade I and II gynaecomastia were recruited (22 bilateral, 14 unilateral). Average age was 33.3 years (range, 16–88 years). All underwent mammotome excision and liposuction. There were no conversions to an open procedure. The average procedure time was 50.3 min (range, 30–80 min). One intra-operative complication was recorded. The minimum follow-up time was 2 months. Thirty-four patients reported excellent satisfaction, two patients had residual gynaecomastia and needed a re-do procedure. Three patients developed small haematomas that resolved spontaneously. CONCLUSION This novel, minimally invasive, surgical approach for gynaecomastia gives excellent results with minimal morbidity. PMID:20412670

Image denoising by a direct variational minimization

NASA Astrophysics Data System (ADS)

Janev, Marko; Atanacković, Teodor; Pilipović, Stevan; Obradović, Radovan

2011-12-01

In this article we introduce a novel method for the image de-noising which combines a mathematically well-posdenes of the variational modeling with the efficiency of a patch-based approach in the field of image processing. It based on a direct minimization of an energy functional containing a minimal surface regularizer that uses fractional gradient. The minimization is obtained on every predefined patch of the image, independently. By doing so, we avoid the use of an artificial time PDE model with its inherent problems of finding optimal stopping time, as well as the optimal time step. Moreover, we control the level of image smoothing on each patch (and thus on the whole image) by adapting the Lagrange multiplier using the information on the level of discontinuities on a particular patch, which we obtain by pre-processing. In order to reduce the average number of vectors in the approximation generator and still to obtain the minimal degradation, we combine a Ritz variational method for the actual minimization on a patch, and a complementary fractional variational principle. Thus, the proposed method becomes computationally feasible and applicable for practical purposes. We confirm our claims with experimental results, by comparing the proposed method with a couple of PDE-based methods, where we get significantly better denoising results specially on the oscillatory regions.

Analysis of single ion channel data incorporating time-interval omission and sampling

PubMed Central

The, Yu-Kai; Timmer, Jens

2005-01-01

Hidden Markov models are widely used to describe single channel currents from patch-clamp experiments. The inevitable anti-aliasing filter limits the time resolution of the measurements and therefore the standard hidden Markov model is not adequate anymore. The notion of time-interval omission has been introduced where brief events are not detected. The developed, exact solutions to this problem do not take into account that the measured intervals are limited by the sampling time. In this case the dead-time that specifies the minimal detectable interval length is not defined unambiguously. We show that a wrong choice of the dead-time leads to considerably biased estimates and present the appropriate equations to describe sampled data. PMID:16849220

End-to-End Network QoS via Scheduling of Flexible Resource Reservation Requests

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharma, S.; Katramatos, D.; Yu, D.

2011-11-14

Modern data-intensive applications move vast amounts of data between multiple locations around the world. To enable predictable and reliable data transfer, next generation networks allow such applications to reserve network resources for exclusive use. In this paper, we solve an important problem (called SMR3) to accommodate multiple and concurrent network reservation requests between a pair of end-sites. Given the varying availability of bandwidth within the network, our goal is to accommodate as many reservation requests as possible while minimizing the total time needed to complete the data transfers. We first prove that SMR3 is an NP-hard problem. Then we solvemore » it by developing a polynomial-time heuristic, called RRA. The RRA algorithm hinges on an efficient mechanism to accommodate large number of requests by minimizing the bandwidth wastage. Finally, via numerical results, we show that RRA constructs schedules that accommodate significantly larger number of requests compared to other, seemingly efficient, heuristics.« less

Temporary Shell Proof-of-Concept Technique: Digital-Assisted Workflow to Enable Customized Immediate Function in Two Visits in Partially Edentulous Patients

PubMed

Pozzi, Alessandro; Arcuri, Lorenzo; Moy, Peter K

2018-03-01

The growing interest in minimally invasive implant placement and delivery of a prefabricated provisional prosthesis immediately, thus minimizing "time to teeth," has led to the development of numerous 3-dimensional (3D) planning software programs. Given the enhancements associated with fully digital workflows, such as better 3D soft-tissue visualization and virtual tooth rendering, computer-guided implant surgery and immediate function has become an effective and reliable procedure. This article describes how modern implant planning software programs provide a comprehensive digital platform that enables efficient interplay between the surgical and restorative aspects of implant treatment. These new technologies that streamline the overall digital workflow allow transformation of the digital wax-up into a personalized, CAD/CAM-milled provisional restoration. Thus, collaborative digital workflows provide a novel approach for time-efficient delivery of a customized, screw-retained provisional restoration on the day of implant surgery, resulting in improved predictability for immediate function in the partially edentate patient.

Spacecraft Environmental Testing SMAP (Soil, Moisture, Active, Passive)

NASA Technical Reports Server (NTRS)

Fields, Keith

2014-01-01

Testing a complete full up spacecraft to verify it will survive the environment, in which it will be exposed to during its mission, is a formidable task in itself. However, the ''test like you fly'' philosophy sometimes gets compromised because of cost, design and or time. This paper describes the thermal-vacuum and mass properties testing of the Soil Moisture Active Passive (SMAP) earth orbiting satellite. SMAP will provide global observations of soil moisture and freeze/thaw state (the hydrosphere state). SMAP hydrosphere state measurements will be used to enhance understanding of processes that link the water, energy, and carbon cycles, and to extend the capabilities of weather and climate prediction models. It will explain the problems encountered, and the solutions developed, which minimized the risk typically associated with such an arduous process. Also discussed, the future of testing on expensive long lead-time spacecraft. Will we ever reach the ''build and shoot" scenario with minimal or no verification testing?

[Transurethral thulium laser urethrotomy for urethral stricture].

PubMed

Liu, Chun-Lai; Zhang, Xi-Ling; Liu, Yi-Li; Wang, Ping

2011-09-01

To evaluate the effect of endourethrotomy with thulium laser as a minimally invasive treatment for urethral stricture. We treated 36 cases of urethral stricture or atresia by endourethrotomy with thulium laser, restored the urethral continuity by vaporization excision of the scar tissue, and observed the clinical effects and complications. The mean operation time was 35 min, ranging from 10 to 90 min. Smooth urination was achieved after 2-6 weeks of catheter indwelling, with no urinary incontinence. The patients were followed up for 4-24 (mean 12) months, during which 27 did not need any reintervention, 5 developed urinary thinning but cured by urethral dilation, 3 received another laser urethrotomy for previous negligence of timely urethral dilation, and the other 1 underwent open urethroplasty. Thulium laser urethrotomy is a safe and effective minimally invasive option for short urethral stricture, which is also suitable for severe urethral stricture and urethral atresia. Its short-term outcome is satisfactory, but its long-term effect remains to be further observed.

Detection of faults in rotating machinery using periodic time-frequency sparsity

NASA Astrophysics Data System (ADS)

Ding, Yin; He, Wangpeng; Chen, Binqiang; Zi, Yanyang; Selesnick, Ivan W.

2016-11-01

This paper addresses the problem of extracting periodic oscillatory features in vibration signals for detecting faults in rotating machinery. To extract the feature, we propose an approach in the short-time Fourier transform (STFT) domain where the periodic oscillatory feature manifests itself as a relatively sparse grid. To estimate the sparse grid, we formulate an optimization problem using customized binary weights in the regularizer, where the weights are formulated to promote periodicity. In order to solve the proposed optimization problem, we develop an algorithm called augmented Lagrangian majorization-minimization algorithm, which combines the split augmented Lagrangian shrinkage algorithm (SALSA) with majorization-minimization (MM), and is guaranteed to converge for both convex and non-convex formulation. As examples, the proposed approach is applied to simulated data, and used as a tool for diagnosing faults in bearings and gearboxes for real data, and compared to some state-of-the-art methods. The results show that the proposed approach can effectively detect and extract the periodical oscillatory features.

Design and fabrication of a real-time measurement system for the capsaicinoid content of Korean red pepper (Capsicum annuum L.) powder by visible and near-infrared spectroscopy

USDA-ARS?s Scientific Manuscript database

This research aims to design and fabricate a system to measure the capsaicinoid content of red pepper powder in a non-destructive and rapid method through visible and near infrared spectroscopy (VNIR). The developed system scans a well-leveled powder surface continuously to minimize the influence of...

Predictive Flow Control to Minimize Convective Time Delays

DTIC Science & Technology

2013-08-19

simulation. The CFO solver used is Cobalt, an unstructured finite-volume code developed for the solution of the compress- ible Navier-Stokes...cell-centered fin ite volume approach applicable to arbitrary cell topologies (e.g, hexahedra, prisms, tetrahedra). The spatial operator uses a Riemann ... solver , least squares gradient calculations using QR factorizati on to provide second order accuracy in space. A point implicit method using

Vibration Analysis Of Automotive Structures Using Holographic Interferometry

NASA Astrophysics Data System (ADS)

Brown, G. M.; Wales, R. R.

1983-10-01

Since 1979, Ford Motor Company has been developing holographic interferometry to supplement more conventional test methods to measure vehicle component vibrations. An Apollo PHK-1 Double Pulse Holographic Laser System was employed to visualize a variety of complex vibration modes, primarily on current production and prototype powertrain components. Design improvements to reduce powertrain response to problem excitations have been deter-mined through pulsed laser holography, and have, in several cases, been put into production in Ford vehicles. Whole-field definition of vibration related deflections provide continuity of information missed by accelerometer/modal analysis techniaues. Certain opera-tional problems, common among pulsed ruby holographic lasers, have reauired ongoing hardware and electronics improvements to minimize system downtime. Real-time, time-averaged and stroboscopic C. W. laser holographic techniques are being developed at Ford to complement the double pulse capabilities and provide rapid identification of modal frequencies and nodal lines for analysis of powertrain structures. Methods for mounting and exciting powertrains to minimize rigid body motions are discussed. Work at Ford will continue toward development of C. W. holographic techniques to provide refined test methodology dedicated to noise and vibration diagnostics with particular emphasis on semi-automated methods for quantifying displacement and relative phase using high resolution digitized video and computers. Continued use of refined pulsed and CW laser holographic interferometry for the analysis of complex structure vibrations seems assured.

Minimization of diauxic growth lag-phase for high-efficiency biogas production.

PubMed

Kim, Min Jee; Kim, Sang Hun

2017-02-01

The objective of this study was to develop a minimization method of a diauxic growth lag-phase for the biogas production from agricultural by-products (ABPs). Specifically, the effects of proximate composition on the biogas production and degradation rates of the ABPs were investigated, and a new method based on proximate composition combinations was developed to minimize the diauxic growth lag-phase. Experiments were performed using biogas potential tests at a substrate loading of 2.5 g VS/L and feed to microorganism ratio (F/M) of 0.5 under the mesophilic condition. The ABPs were classified based on proximate composition (carbohydrate, protein, and fat etc.). The biogas production patterns, lag phase, and times taken for 90% biogas production (T90) were used for the evaluation of the biogas production with biochemical methane potential (BMP) test. The high- or medium-carbohydrate and low-fat ABPs (cheese whey, cabbage, and skim milk) showed a single step digestion process and low-carbohydrate and high-fat ABPs (bean curd and perilla seed) showed a two-step digestion process. The mixture of high-fat ABPs and high-carbohydrate ABPs reduced the lag-phase and increased the biogas yield more than that from single ABP by 35-46%. Copyright © 2016 Elsevier Ltd. All rights reserved.

Recursive multibody dynamics and discrete-time optimal control

NASA Technical Reports Server (NTRS)

Deleuterio, G. M. T.; Damaren, C. J.

1989-01-01

A recursive algorithm is developed for the solution of the simulation dynamics problem for a chain of rigid bodies. Arbitrary joint constraints are permitted, that is, joints may allow translational and/or rotational degrees of freedom. The recursive procedure is shown to be identical to that encountered in a discrete-time optimal control problem. For each relevant quantity in the multibody dynamics problem, there exists an analog in the context of optimal control. The performance index that is minimized in the control problem is identified as Gibbs' function for the chain of bodies.

Automated planning for intelligent machines in energy-related applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weisbin, C.R.; de Saussure, G.; Barhen, J.

1984-01-01

This paper discusses the current activities of the Center for Engineering Systems Advanced Research (CESAR) program related to plan generation and execution by an intelligent machine. The system architecture for the CESAR mobile robot (named HERMIES-1) is described. The minimal cut-set approach is developed to reduce the tree search time of conventional backward chaining planning techniques. Finally, a real-time concept of an Intelligent Machine Operating System is presented in which planning and reasoning is embedded in a system for resource allocation and process management.

Automatic Radiated Susceptibility Test System for Payload Equipment

NASA Technical Reports Server (NTRS)

Ngo, Hoai T.; Sturman, John C.; Sargent, Noel B.

1995-01-01

An automatic radiated susceptibility test system (ARSTS) was developed for NASA Lewis Research Center's Electro-magnetic Interference laboratory. According to MSFC-SPEC 521B, any electrical or electronic equipment that will be transported by the spacelab and space shuttle must be tested for susceptibility to electromagnetic interference. This state-of-the-art automatic test system performs necessary calculations; analyzes, processes, and records a great quantity of measured data; and monitors the equipment being tested in real-time and with minimal user intervention. ARSTS reduces costly test time, increases test accuracy, and provides reliable test results.

Continued driving and time to transition to nondriver status through error-specific driving restrictions.

PubMed

Freund, Barbara; Petrakos, Davithoula

2008-01-01

We developed driving restrictions that are linked to specific driving errors, allowing cognitively impaired individuals to continue to independently meet mobility needs while minimizing risk to themselves and others. The purpose of this project was to evaluate the efficacy and duration expectancy of these restrictions in promoting safe continued driving. We followed 47 drivers age 60 years and older for 18 months, evaluating driving performance at 6-month intervals. Results demonstrated restricted drivers had safety profiles similar to safe drivers and gained additional driving time to transition to nondrivers.

Utilizing Fission Technology to Enable Rapid and Affordable Access to any Point in the Solar System

NASA Technical Reports Server (NTRS)

Houts, Mike; Bonometti, Joe; Morton, Jeff; Hrbud, Ivana; Bitteker, Leo; VanDyke, Melissa; Godfroy, T.; Pedersen, K.; Dobson, C.; Patton, B.;

The development of confocal arthroscopy as optical histology for rotator cuff tendinopathy.

PubMed

Wu, J-P; Walton, M; Wang, A; Anderson, P; Wang, T; Kirk, T B; Zheng, M H

2015-09-01

MRI, ultrasound and video arthroscopy are traditional imaging technologies for noninvasive or minimal invasive assessment of the rotator cuff tendon pathology. However, these imaging modalities do not have sufficient resolution to demonstrate the pathology of rotator cuff tendons at a microstructural level. Therefore, they are insensitive to low-level tendon diseases. Although traditional histology can be used to analyze the physiology of rotator cuff tendons, it requires biopsy that traumatizes the rotator cuff, thus, potentially comprising the mechanical properties of tendons. Besides, it cannot offer real-time histological information. Confocal endoscopy offers a way to assess the microstructural disorder in tissues without biopsy. However, the application of this useful technique for detecting low-level tendon diseases has been restricted by using clinical grade fluorescent contrast agent to acquire high-resolution microstructural images of tendons. In this study, using a clinical grade sodium fluorescein contrast agent, we have reported the development of confocal arthroscopy for optical histological assessment without biopsy. The confocal arthroscopic technique was able to demonstrate rotator cuff tendinopathy in human cadavers, which appeared macroscopically normal under video arthroscopic examinations. The tendinopathy status of the rotator cuff tendons was confirmed by corresponding traditional histology. The development of confocal arthroscopy may provide a minimally invasive imaging technique for real-time histology of rotator cuff without the need for tissue biopsy. This technique has the potential for surgeons to gain in real time the histological information of rotator cuff tendons, which may assist planning repair strategies and potentially improve intervention outcomes. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

Computer-Aided Systems Engineering for Flight Research Projects Using a Workgroup Database

NASA Technical Reports Server (NTRS)

Mizukami, Masahi

2004-01-01

An online systems engineering tool for flight research projects has been developed through the use of a workgroup database. Capabilities are implemented for typical flight research systems engineering needs in document library, configuration control, hazard analysis, hardware database, requirements management, action item tracking, project team information, and technical performance metrics. Repetitive tasks are automated to reduce workload and errors. Current data and documents are instantly available online and can be worked on collaboratively. Existing forms and conventional processes are used, rather than inventing or changing processes to fit the tool. An integrated tool set offers advantages by automatically cross-referencing data, minimizing redundant data entry, and reducing the number of programs that must be learned. With a simplified approach, significant improvements are attained over existing capabilities for minimal cost. By using a workgroup-level database platform, personnel most directly involved in the project can develop, modify, and maintain the system, thereby saving time and money. As a pilot project, the system has been used to support an in-house flight experiment. Options are proposed for developing and deploying this type of tool on a more extensive basis.

On evolutionary systems.

PubMed

Alvarez de Lorenzana, J M; Ward, L M

1987-01-01

This paper develops a metatheoretical framework for understanding evolutionary systems (systems that develop in ways that increase their own variety). The framework addresses shortcomings seen in other popular systems theories. It concerns both living and nonliving systems, and proposes a metahierarchy of hierarchical systems. Thus, it potentially addresses systems at all descriptive levels. We restrict our definition of system to that of a core system whose parts have a different ontological status than the system, and characterize the core system in terms of five global properties: minimal length interval, minimal time interval, system cycle, total receptive capacity, and system potential. We propose two principles through the interaction of which evolutionary systems develop. The Principle of Combinatorial Expansion describes how a core system realizes its developmental potential through a process of progressive differentiation of the single primal state up to a limit stage. The Principle of Generative Condensation describes how the components of the last stage of combinatorial expansion condense and become the environment for and components of new, enriched systems. The early evolution of the Universe after the "big bang" is discussed in light of these ideas as an example of the application of the framework.

A model for developing job rotation schedules that eliminate sequential high workloads and minimize between-worker variability in cumulative daily workloads: Application to automotive assembly lines.

PubMed

Yoon, Sang-Young; Ko, Jeonghan; Jung, Myung-Chul

2016-07-01

The aim of study is to suggest a job rotation schedule by developing a mathematical model in order to reduce cumulative workload from the successive use of the same body region. Workload assessment using rapid entire body assessment (REBA) was performed for the model in three automotive assembly lines of chassis, trim, and finishing to identify which body part exposed to relatively high workloads at workstations. The workloads were incorporated to the model to develop a job rotation schedule. The proposed schedules prevent the exposure to high workloads successively on the same body region and minimized between-worker variance in cumulative daily workload. Whereas some of workers were successively assigned to high workload workstation under no job rotation and serial job rotation. This model would help to reduce the potential for work-related musculoskeletal disorders (WMSDs) without additional cost for engineering work, although it may need more computational time and relative complex job rotation sequences. Copyright © 2016 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Minimally Invasive Surgery for the Treatment of Colorectal Cancer

PubMed Central

Karcz, W. Konrad; von Braun, William

2016-01-01

Background Reduction in operative trauma along with an improvement in endoscopic access has undoubtedly occupied surgical minds for at least the past 3 decades. It is not at all surprising that minimally invasive colon surgery has come a long way since the first laparoscopic appendectomy by Semm in 1981. It is common knowledge that the recent developments in video and robotic technologies have significantly furthered advancements in laparoscopic and minimally invasive surgery. This has led to the overall acceptance of the treatment of benign colorectal pathology via the endoscopic route. Malignant disease, however, is still primarily treated by conventional approaches. Methods and Results This review article is based on a literature search pertaining to advances in minimally invasive colorectal surgery for the treatment of malignant pathology, as well as on personal experience in the field over the same period of time. Our search was limited to level I and II clinical papers only, according to the evidence-based medicine guidelines. We attempted to present our unbiased view on the subject relying only on the evidence available. Conclusion Focusing on advances in colorectal minimally invasive surgery, it has to be stated that there are still a number of unanswered questions regarding the surgical management of malignant diseases with this approach. These questions do not only relate to the area of boundaries set for the use of minimally invasive techniques in this field but also to the exact modality best suited to the treatment of every particular case whilst maintaining state-of-the-art oncological principles. PMID:27493947

Space Station Information Systems

NASA Technical Reports Server (NTRS)

Pittman, Clarence W.

1988-01-01

The utility of the Space Station is improved, the ability to manage and integrate its development and operation enhanced, and the cost and risk of developing the software for it is minimized by three major information systems. The Space Station Information System (SSIS) provides for the transparent collection and dissemination of operational information to all users and operators. The Technical and Management Information System (TMIS) provides all the developers with timely and consistent program information and a project management 'window' to assess the project status. The Software Support Environment (SSE) provides automated tools and standards to be used by all software developers. Together, these three systems are vital to the successful execution of the program.

Risk Interfaces to Support Integrated Systems Analysis and Development

NASA Technical Reports Server (NTRS)

Mindock, Jennifer; Lumpkins, Sarah; Shelhamer, Mark; Anton, Wilma; Havenhill, Maria

2016-01-01

Objectives for systems analysis capability: Develop integrated understanding of how a complex human physiological-socio-technical mission system behaves in spaceflight. Why? Support development of integrated solutions that prevent unwanted outcomes (Implementable approaches to minimize mission resources(mass, power, crew time, etc.)); Support development of tools for autonomy (need for exploration) (Assess and maintain resilience -individuals, teams, integrated system). Output of this exercise: -Representation of interfaces based on Human System Risk Board (HSRB) Risk Summary information and simple status based on Human Research Roadmap; Consolidated HSRB information applied to support communication; Point-of-Departure for HRP Element planning; Ability to track and communicate status of collaborations. 4

Spatial Optimization of Future Urban Development with Regards to Climate Risk and Sustainability Objectives.

PubMed

Caparros-Midwood, Daniel; Barr, Stuart; Dawson, Richard

2017-11-01

Future development in cities needs to manage increasing populations, climate-related risks, and sustainable development objectives such as reducing greenhouse gas emissions. Planners therefore face a challenge of multidimensional, spatial optimization in order to balance potential tradeoffs and maximize synergies between risks and other objectives. To address this, a spatial optimization framework has been developed. This uses a spatially implemented genetic algorithm to generate a set of Pareto-optimal results that provide planners with the best set of trade-off spatial plans for six risk and sustainability objectives: (i) minimize heat risks, (ii) minimize flooding risks, (iii) minimize transport travel costs to minimize associated emissions, (iv) maximize brownfield development, (v) minimize urban sprawl, and (vi) prevent development of greenspace. The framework is applied to Greater London (U.K.) and shown to generate spatial development strategies that are optimal for specific objectives and differ significantly from the existing development strategies. In addition, the analysis reveals tradeoffs between different risks as well as between risk and sustainability objectives. While increases in heat or flood risk can be avoided, there are no strategies that do not increase at least one of these. Tradeoffs between risk and other sustainability objectives can be more severe, for example, minimizing heat risk is only possible if future development is allowed to sprawl significantly. The results highlight the importance of spatial structure in modulating risks and other sustainability objectives. However, not all planning objectives are suited to quantified optimization and so the results should form part of an evidence base to improve the delivery of risk and sustainability management in future urban development. © 2017 The Authors Risk Analysis published by Wiley Periodicals, Inc. on behalf of Society for Risk Analysis.

Scheduling with non-decreasing deterioration jobs and variable maintenance activities on a single machine

NASA Astrophysics Data System (ADS)

Zhang, Xingong; Yin, Yunqiang; Wu, Chin-Chia

2017-01-01

There is a situation found in many manufacturing systems, such as steel rolling mills, fire fighting or single-server cycle-queues, where a job that is processed later consumes more time than that same job when processed earlier. The research finds that machine maintenance can improve the worsening of processing conditions. After maintenance activity, the machine will be restored. The maintenance duration is a positive and non-decreasing differentiable convex function of the total processing times of the jobs between maintenance activities. Motivated by this observation, the makespan and the total completion time minimization problems in the scheduling of jobs with non-decreasing rates of job processing time on a single machine are considered in this article. It is shown that both the makespan and the total completion time minimization problems are NP-hard in the strong sense when the number of maintenance activities is arbitrary, while the makespan minimization problem is NP-hard in the ordinary sense when the number of maintenance activities is fixed. If the deterioration rates of the jobs are identical and the maintenance duration is a linear function of the total processing times of the jobs between maintenance activities, then this article shows that the group balance principle is satisfied for the makespan minimization problem. Furthermore, two polynomial-time algorithms are presented for solving the makespan problem and the total completion time problem under identical deterioration rates, respectively.

Sharp-Tailed Grouse Nest Survival and Nest Predator Habitat Use in North Dakota's Bakken Oil Field.

PubMed

Burr, Paul C; Robinson, Aaron C; Larsen, Randy T; Newman, Robert A; Ellis-Felege, Susan N

2017-01-01

Recent advancements in extraction technologies have resulted in rapid increases of gas and oil development across the United States and specifically in western North Dakota. This expansion of energy development has unknown influences on local wildlife populations and the ecological interactions within and among species. Our objectives for this study were to evaluate nest success and nest predator dynamics of sharp-tailed grouse (Tympanuchus phasianellus) in two study sites that represented areas of high and low energy development intensities in North Dakota. During the summers of 2012 and 2013, we monitored 163 grouse nests using radio telemetry. Of these, 90 nests also were monitored using miniature cameras to accurately determine nest fates and identify nest predators. We simultaneously conducted predator surveys using camera scent stations and occupancy modeling to estimate nest predator occurrence at each site. American badgers (Taxidea taxus) and striped skunks (Mephitis mephitis) were the primary nest predators, accounting for 56.7% of all video recorded nest depredations. Nests in our high intensity gas and oil area were 1.95 times more likely to succeed compared to our minimal intensity area. Camera monitored nests were 2.03 times more likely to succeed than non-camera monitored nests. Occupancy of mammalian nest predators was 6.9 times more likely in our study area of minimal gas and oil intensity compared to the high intensity area. Although only a correlative study, our results suggest energy development may alter the predator community, thereby increasing nest success for sharp-tailed grouse in areas of intense development, while adjacent areas may have increased predator occurrence and reduced nest success. Our study illustrates the potential influences of energy development on the nest predator-prey dynamics of sharp-tailed grouse in western North Dakota and the complexity of evaluating such impacts on wildlife.

Maximum height and minimum time vertical jumping.

PubMed

Domire, Zachary J; Challis, John H

2015-08-20

The performance criterion in maximum vertical jumping has typically been assumed to simply raise the center of mass as high as possible. In many sporting activities minimizing movement time during the jump is likely also critical to successful performance. The purpose of this study was to examine maximum height jumps performed while minimizing jump time. A direct dynamics model was used to examine squat jump performance, with dual performance criteria: maximize jump height and minimize jump time. The muscle model had activation dynamics, force-length, force-velocity properties, and a series of elastic component representing the tendon. The simulations were run in two modes. In Mode 1 the model was placed in a fixed initial position. In Mode 2 the simulation model selected the initial squat configuration as well as the sequence of muscle activations. The inclusion of time as a factor in Mode 1 simulations resulted in a small decrease in jump height and moderate time savings. The improvement in time was mostly accomplished by taking off from a less extended position. In Mode 2 simulations, more substantial time savings could be achieved by beginning the jump in a more upright posture. However, when time was weighted more heavily in these simulations, there was a more substantial reduction in jump height. Future work is needed to examine the implications for countermovement jumping and to examine the possibility of minimizing movement time as part of the control scheme even when the task is to jump maximally. Copyright © 2015 Elsevier Ltd. All rights reserved.

New design conception and development of the synchronizer/data buffer system in CDA station for China's GMS

NASA Astrophysics Data System (ADS)

Tong, Kai; Fan, Shiming; Gong, Derong; Lu, Zuming; Liu, Jian

The synchronizer/data buffer (SDB) in the command and data acquisition station for China's future Geostationary Meteorological Satellite is described. Several computers and special microprocessors are used in tandem with minimized hardware to fulfill all of the functions. The high-accuracy digital phase locked loop is operated by computer and by controlling the count value of the 20-MHz clock to acquire and track such signals as sun pulse, scan synchronization detection pulse, and earth pulse. Sun pulse and VISSR data are recorded precisely and economically by digitizing the time relation. The VISSR scan timing and equiangular control timing, and equal time sampling on satellite are also discussed.

Improving both imaging speed and spatial resolution in MR-guided neurosurgery

NASA Astrophysics Data System (ADS)

Liu, Haiying; Hall, Walter A.; Truwit, Charles L.

2002-05-01

A robust near real-time MRI based surgical guidance scheme has been developed and used in neurosurgical procedure performed in our combined 1.5 Tesla MR operating room. Because of the increased susceptibility difference in the area of surgical site during surgery, the preferred real- time imaging technique is a single shot imaging sequence based on the concept of the half acquisition with turbo spin echoes (HASTE). In order to maintain sufficient spatial resolution for visualizing the surgical devices, such as a biopsy needle and catheter, we used focused field of view (FOV) in the phase-encoding (PE) direction coupled with an out-volume signal suppression (OVS) technique. The key concept of the method is to minimize the total number of the required phase encoding steps and the effective echo time (TE) as well as the longest TE for the high spatial encoding step. The concept has been first demonstrated with a phantom experiment, which showed when the water was doped with Gd- DTPA to match the relaxation rates of the brain tissue there was a significant spatial blurring primarily along the phase encoding direction if the conventional HASTE technique, and the new scheme indeed minimized the spatial blur in the resulting image and improved the needle visualization as anticipated. Using the new scheme in a typical MR-guided neurobiopsy procedure, the brain biopsy needle was easily seen against the tissue background with minimal blurring due the inevitable T2 signal decay even when the PE direction was set parallel to the needle axis. This MR based guidance technique has practically allowed neurosurgeons to visualize the biopsy needle and to monitor its insertion with a better certainty at near real-time pace.

Minimizing the Sum of Completion Times with Resource Dependant Times

NASA Astrophysics Data System (ADS)

Yedidsion, Liron; Shabtay, Dvir; Kaspi, Moshe

2008-10-01

We extend the classical minimization sum of completion times problem to the case where the processing times are controllable by allocating a nonrenewable resource. The quality of a solution is measured by two different criteria. The first criterion is the sum of completion times and the second is the total weighted resource consumption. We consider four different problem variations for treating the two criteria. We prove that this problem is NP-hard for three of the four variations even if all resource consumption weights are equal. However, somewhat surprisingly, the variation of minimizing the integrated objective function is solvable in polynomial time. Although the sum of completion times is arguably the most important scheduling criteria, the complexity of this problem, up to this paper, was an open question for three of the four variations. The results of this research have various implementations, including efficient battery usage on mobile devices such as mobile computer, phones and GPS devices in order to prolong their battery duration.

A feasibility investigation for modeling and optimization of temperature in bone drilling using fuzzy logic and Taguchi optimization methodology.

PubMed

Pandey, Rupesh Kumar; Panda, Sudhansu Sekhar

2014-11-01

Drilling of bone is a common procedure in orthopedic surgery to produce hole for screw insertion to fixate the fracture devices and implants. The increase in temperature during such a procedure increases the chances of thermal invasion of bone which can cause thermal osteonecrosis resulting in the increase of healing time or reduction in the stability and strength of the fixation. Therefore, drilling of bone with minimum temperature is a major challenge for orthopedic fracture treatment. This investigation discusses the use of fuzzy logic and Taguchi methodology for predicting and minimizing the temperature produced during bone drilling. The drilling experiments have been conducted on bovine bone using Taguchi's L25 experimental design. A fuzzy model is developed for predicting the temperature during orthopedic drilling as a function of the drilling process parameters (point angle, helix angle, feed rate and cutting speed). Optimum bone drilling process parameters for minimizing the temperature are determined using Taguchi method. The effect of individual cutting parameters on the temperature produced is evaluated using analysis of variance. The fuzzy model using triangular and trapezoidal membership predicts the temperature within a maximum error of ±7%. Taguchi analysis of the obtained results determined the optimal drilling conditions for minimizing the temperature as A3B5C1.The developed system will simplify the tedious task of modeling and determination of the optimal process parameters to minimize the bone drilling temperature. It will reduce the risk of thermal osteonecrosis and can be very effective for the online condition monitoring of the process. © IMechE 2014.

Automation of a suturing device for minimally invasive surgery.

PubMed

Göpel, Tobias; Härtl, Felix; Schneider, Armin; Buss, Martin; Feussner, Hubertus

2011-07-01

In minimally invasive surgery, hand suturing is categorized as a challenge in technique as well as in its duration. This calls for an easily manageable tool, permitting an all-purpose, cost-efficient, and secure viscerosynthesis. Such a tool for this field already exists: the Autosuture EndoStitch(®). In a series of studies the potential for the EndoStitch to accelerate suturing has been proven. However, its ergonomics still limits its applicability. The goal of this study was twofold: propose an optimized and partially automated EndoStitch and compare the conventional EndoStitch to the optimized and partially automated EndoStitch with respect to the speed and precision of suturing. Based on the EndoStitch, a partially automated suturing tool has been developed. With the aid of a DC motor, triggered by a button, one can suture by one-fingered handling. Using the partially automated suturing manipulator, 20 surgeons with different levels of laparoscopic experience successfully completed a continuous suture with 10 stitches using the conventional and the partially automated suture manipulator. Before that, each participant was given 1 min of instruction and 1 min for training. Absolute suturing time and stitch accuracy were measured. The quality of the automated EndoStitch with respect to manipulation was tested with the aid of a standardized questionnaire. To compare the two instruments, t tests were used for suturing accuracy and time. Of the 20 surgeons with laparoscopic experience (fewer than 5 laparoscopic interventions, n=9; fewer than 20 laparoscopic interventions, n=7; more than 20 laparoscopic interventions, n=4), there was no significant difference between the two tested systems with respect to stitching accuracy. However, the suturing time was significantly shorter with the Autostitch (P=0.01). The difference in accuracy and speed was not statistically significant considering the laparoscopic experience of the surgeons. The weight and size of the Autostitch have been criticized as well as its cable. However, the comfortable handhold, automatic needle change, and ergonomic manipulation have been rated positive. Partially automated suturing in minimally invasive surgery offers advantages with respect to the speed of operation and ergonomics. Ongoing work in this field has to concentrate on minimization, implementation in robotic systems, and development of new operation methods (NOTES).

An Outcome and Cost Analysis Comparing Single-Level Minimally Invasive Transforaminal Lumbar Interbody Fusion Using Intraoperative Fluoroscopy versus Computed Tomography-Guided Navigation.

PubMed

Khanna, Ryan; McDevitt, Joseph L; Abecassis, Zachary A; Smith, Zachary A; Koski, Tyler R; Fessler, Richard G; Dahdaleh, Nader S

2016-10-01

Minimally invasive transforaminal lumbar interbody fusion (TLIF) has undergone significant evolution since its conception as a fusion technique to treat lumbar spondylosis. Minimally invasive TLIF is commonly performed using intraoperative two-dimensional fluoroscopic x-rays. However, intraoperative computed tomography (CT)-based navigation during minimally invasive TLIF is gaining popularity for improvements in visualizing anatomy and reducing intraoperative radiation to surgeons and operating room staff. This is the first study to compare clinical outcomes and cost between these 2 imaging techniques during minimally invasive TILF. For comparison, 28 patients who underwent single-level minimally invasive TLIF using fluoroscopy were matched to 28 patients undergoing single-level minimally invasive TLIF using CT navigation based on race, sex, age, smoking status, payer type, and medical comorbidities (Charlson Comorbidity Index). The minimum follow-up time was 6 months. The 2 groups were compared in regard to clinical outcomes and hospital reimbursement from the payer perspective. Average surgery time, anesthesia time, and hospital length of stay were similar for both groups, but average estimated blood loss was lower in the fluoroscopy group compared with the CT navigation group (154 mL vs. 262 mL; P = 0.016). Oswestry Disability Index, back visual analog scale, and leg visual analog scale scores similarly improved in both groups (P > 0.05) at 6-month follow-up. Cost analysis showed that average hospital payments were similar in the fluoroscopy versus the CT navigation groups ($32,347 vs. $32,656; P = 0.925) as well as payments for the operating room (P = 0.868). Single minimally invasive TLIF performed with fluoroscopy versus CT navigation showed similar clinical outcomes and cost at 6 months. Copyright © 2016 Elsevier Inc. All rights reserved.

Analysis of labor employment assessment on production machine to minimize time production

NASA Astrophysics Data System (ADS)

Hernawati, Tri; Suliawati; Sari Gumay, Vita

2018-03-01

Every company both in the field of service and manufacturing always trying to pass efficiency of it’s resource use. One resource that has an important role is labor. Labor has different efficiency levels for different jobs anyway. Problems related to the optimal allocation of labor that has different levels of efficiency for different jobs are called assignment problems, which is a special case of linear programming. In this research, Analysis of Labor Employment Assesment on Production Machine to Minimize Time Production, in PT PDM is done by using Hungarian algorithm. The aim of the research is to get the assignment of optimal labor on production machine to minimize time production. The results showed that the assignment of existing labor is not suitable because the time of completion of the assignment is longer than the assignment by using the Hungarian algorithm. By applying the Hungarian algorithm obtained time savings of 16%.

An optimal policy for deteriorating items with time-proportional deterioration rate and constant and time-dependent linear demand rate

NASA Astrophysics Data System (ADS)

Singh, Trailokyanath; Mishra, Pandit Jagatananda; Pattanayak, Hadibandhu

2017-12-01

In this paper, an economic order quantity (EOQ) inventory model for a deteriorating item is developed with the following characteristics: (i) The demand rate is deterministic and two-staged, i.e., it is constant in first part of the cycle and linear function of time in the second part. (ii) Deterioration rate is time-proportional. (iii) Shortages are not allowed to occur. The optimal cycle time and the optimal order quantity have been derived by minimizing the total average cost. A simple solution procedure is provided to illustrate the proposed model. The article concludes with a numerical example and sensitivity analysis of various parameters as illustrations of the theoretical results.

Resource Constrained Planning of Multiple Projects with Separable Activities

NASA Astrophysics Data System (ADS)

Fujii, Susumu; Morita, Hiroshi; Kanawa, Takuya

In this study we consider a resource constrained planning problem of multiple projects with separable activities. This problem provides a plan to process the activities considering a resource availability with time window. We propose a solution algorithm based on the branch and bound method to obtain the optimal solution minimizing the completion time of all projects. We develop three methods for improvement of computational efficiency, that is, to obtain initial solution with minimum slack time rule, to estimate lower bound considering both time and resource constraints and to introduce an equivalence relation for bounding operation. The effectiveness of the proposed methods is demonstrated by numerical examples. Especially as the number of planning projects increases, the average computational time and the number of searched nodes are reduced.

Chemical Detection and Identification Techniques for Exobiology Flight Experiments

NASA Technical Reports Server (NTRS)

Kojiro, Daniel R.; Sheverev, Valery A.; Khromov, Nikolai A.

2002-01-01

Exobiology flight experiments require highly sensitive instrumentation for in situ analysis of the volatile chemical species that occur in the atmospheres and surfaces of various bodies within the solar system. The complex mixtures encountered place a heavy burden on the analytical Instrumentation to detect and identify all species present. The minimal resources available onboard for such missions mandate that the instruments provide maximum analytical capabilities with minimal requirements of volume, weight and consumables. Advances in technology may be achieved by increasing the amount of information acquired by a given technique with greater analytical capabilities and miniaturization of proven terrestrial technology. We describe here methods to develop analytical instruments for the detection and identification of a wide range of chemical species using Gas Chromatography. These efforts to expand the analytical capabilities of GC technology are focused on the development of detectors for the GC which provide sample identification independent of the GC retention time data. A novel new approach employs Penning Ionization Electron Spectroscopy (PIES).

Surface inspection system for industrial components based on shape from shading minimization approach

NASA Astrophysics Data System (ADS)

Kotan, Muhammed; Öz, Cemil

2017-12-01

An inspection system using estimated three-dimensional (3-D) surface characteristics information to detect and classify the faults to increase the quality control on the frequently used industrial components is proposed. Shape from shading (SFS) is one of the basic and classic 3-D shape recovery problems in computer vision. In our application, we developed a system using Frankot and Chellappa SFS method based on the minimization of the selected basis function. First, the specialized image acquisition system captured the images of the component. To eliminate noise, wavelet transform is applied to the taken images. Then, estimated gradients were used to obtain depth and surface profiles. Depth information was used to determine and classify the surface defects. Also, a comparison made with some linearization-based SFS algorithms was discussed. The developed system was applied to real products and the results indicated that using SFS approaches is useful and various types of defects can easily be detected in a short period of time.

The Development of Patient Scheduling Groups for an Effective Appointment System

PubMed Central

2016-01-01

Summary Background Patient access to care and long wait times has been identified as major problems in outpatient delivery systems. These aspects impact medical staff productivity, service quality, clinic efficiency, and health-care cost. Objectives This study proposed to redesign existing patient types into scheduling groups so that the total cost of clinic flow and scheduling flexibility was minimized. The optimal scheduling group aimed to improve clinic efficiency and accessibility. Methods The proposed approach used the simulation optimization technique and was demonstrated in a Primary Care physician clinic. Patient type included, emergency/urgent care (ER/UC), follow-up (FU), new patient (NP), office visit (OV), physical exam (PE), and well child care (WCC). One scheduling group was designed for this physician. The approach steps were to collect physician treatment time data for each patient type, form the possible scheduling groups, simulate daily clinic flow and patient appointment requests, calculate costs of clinic flow as well as appointment flexibility, and find the scheduling group that minimized the total cost. Results The cost of clinic flow was minimized at the scheduling group of four, an 8.3% reduction from the group of one. The four groups were: 1. WCC, 2. OV, 3. FU and ER/UC, and 4. PE and NP. The cost of flexibility was always minimized at the group of one. The total cost was minimized at the group of two. WCC was considered separate and the others were grouped together. The total cost reduction was 1.3% from the group of one. Conclusions This study provided an alternative method of redesigning patient scheduling groups to address the impact on both clinic flow and appointment accessibility. Balance between them ensured the feasibility to the recognized issues of patient service and access to care. The robustness of the proposed method on the changes of clinic conditions was also discussed. PMID:27081406

Design-for-Six-Sigma To Develop a Bioprocess Knowledge Management Framework.

PubMed

Junker, Beth; Maheshwari, Gargi; Ranheim, Todd; Altaras, Nedim; Stankevicz, Michael; Harmon, Lori; Rios, Sandra; D'anjou, Marc

2011-01-01

Owing to the high costs associated with biopharmaceutical development, considerable pressure has developed for the biopharmaceutical industry to increase productivity by becoming more lean and flexible. The ability to reuse knowledge was identified as one key advantage to streamline productivity, efficiently use resources, and ultimately perform better than the competition. A knowledge management (KM) strategy was assembled for bioprocess-related information using the technique of Design-for-Six-Sigma (DFSS). This strategy supported quality-by-design and process validation efforts for pipeline as well as licensed products. The DFSS technique was selected because it was both streamlined and efficient. These characteristics permitted development of a KM strategy with minimized team leader and team member resources. DFSS also placed a high emphasis on the voice of the customer, information considered crucial to the selection of solutions most appropriate for the current knowledge-based challenges of the organization. The KM strategy developed was comprised of nine workstreams, constructed from related solution buckets which in turn were assembled from the individual solution tasks that were identified. Each workstream's detailed design was evaluated against published and established best practices, as well as the KM strategy project charter and design inputs. Gaps and risks were identified and mitigated as necessary to improve the robustness of the proposed strategy. Aggregated resources (specifically expense/capital funds and staff) and timing were estimated to obtain vital management sponsorship for implementation. Where possible, existing governance and divisional/corporate information technology efforts were leveraged to minimize the additional bioprocess resources required for implementation. Finally, leading and lagging indicator metrics were selected to track the success of pilots and eventual implementation. A knowledge management framework was assembled for bioprocess-related information using a streamlined and efficient technique that minimized team leader and member resources. The technique also highly emphasized input from the staff, who generated and used the knowledge, information considered crucial to selection of solutions most appropriate for the current knowledge-based challenges in the organization. The framework developed was comprised of nine workstreams, constructed from related solution buckets which were assembled from individual solution tasks that were identified. Each workstream's detailed design was evaluated against published and established best practices, as well as the project charter and design inputs. Gaps and risks were identified and mitigated to improve robustness of the proposed framework. Aggregated resources (specifically expense/capital funds and staff) and timing were estimated to obtain vital management sponsorship for implementation. Where possible, existing governance and information technology efforts were leveraged to minimize additional bioprocess resources required for implementation. Finally, metrics were selected to track the success of pilots and eventual implementation.

Flip-Flop Recovery System for sounding rocket payloads

NASA Technical Reports Server (NTRS)

Flores, A., Jr.

1986-01-01

The design, development, and testing of the Flip-Flop Recovery System, which protects sensitive forward-mounted instruments from ground impact during sounding rocket payload recovery operations, are discussed. The system was originally developed to reduce the impact damage to the expensive gold-plated forward-mounted spectrometers in two existing Taurus-Orion rocket payloads. The concept of the recovery system is simple: the payload is flipped over end-for-end at a predetermined time just after parachute deployment, thus minimizing the risk of damage to the sensitive forward portion of the payload from ground impact.

OSI for hardware/software interoperability

NASA Astrophysics Data System (ADS)

Wood, Richard J.; Harvey, Donald L.; Linderman, Richard W.; Gardener, Gary A.; Capraro, Gerard T.

1994-03-01

There is a need in public safety for real-time data collection and transmission from one or more sensors. The Rome Laboratory and the Ballistic Missile Defense Organization are pursuing an effort to bring the benefits of Open System Architectures (OSA) to embedded systems within the Department of Defense. When developed properly OSA provides interoperability, commonality, graceful upgradeability, survivability and hardware/software transportability to greatly minimize life cycle costs, integration and supportability. Architecture flexibility can be achieved to take advantage of commercial accomplishments by basing these developments on vendor-neutral commercially accepted standards and protocols.

[Toxic polyneuropathy after sniffing contact glue thinner (author's transl)].

PubMed

Altenkirch, H; Mager, J

1976-02-06

Four men aged 16 to 19 years who had sniffed contact glue ("Pattex") thinner almost daily for 3 to 7 years developed a pronounced polyneuropathy. They had to be admitted nearly at the same time. A uniform neurological syndrome similar to Landry's paralysis with progressive ascending symmetrical pareses had developed. Motor deficiencies and atrophies affected the lower extremities more frequently and more severely. Only minimal sensory disturbances were found. The disease shows remarkable similarity to the "glue-sniffing neuropathy" described in the US and Japan which is attributed to n-hexane.

Adaptive Implicit Non-Equilibrium Radiation Diffusion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Philip, Bobby; Wang, Zhen; Berrill, Mark A

2013-01-01

We describe methods for accurate and efficient long term time integra- tion of non-equilibrium radiation diffusion systems: implicit time integration for effi- cient long term time integration of stiff multiphysics systems, local control theory based step size control to minimize the required global number of time steps while control- ling accuracy, dynamic 3D adaptive mesh refinement (AMR) to minimize memory and computational costs, Jacobian Free Newton-Krylov methods on AMR grids for efficient nonlinear solution, and optimal multilevel preconditioner components that provide level independent solver convergence.

Wavefront optimized nonlinear microscopy of ex vivo human retinas

NASA Astrophysics Data System (ADS)

Gualda, Emilio J.; Bueno, Juan M.; Artal, Pablo

2010-03-01

A multiphoton microscope incorporating a Hartmann-Shack (HS) wavefront sensor to control the ultrafast laser beam's wavefront aberrations has been developed. This instrument allowed us to investigate the impact of the laser beam aberrations on two-photon autofluorescence imaging of human retinal tissues. We demonstrated that nonlinear microscopy images are improved when laser beam aberrations are minimized by realigning the laser system cavity while wavefront controlling. Nonlinear signals from several human retinal anatomical features have been detected for the first time, without the need of fixation or staining procedures. Beyond the improved image quality, this approach reduces the required excitation power levels, minimizing the side effects of phototoxicity within the imaged sample. In particular, this may be important to study the physiology and function of the healthy and diseased retina.

Endoscopic ultrasound-guided biliary drainage

PubMed Central

Chavalitdhamrong, Disaya; Draganov, Peter V

2012-01-01

Endoscopic ultrasound (EUS)-guided biliary drainage has emerged as a minimally invasive alternative to percutaneous and surgical interventions for patients with biliary obstruction who had failed endoscopic retrograde cholangiopancreatography (ERCP). EUS-guided biliary drainage has become feasible due to the development of large channel curvilinear therapeutic echo-endoscopes and the use of real-time ultrasound and fluoroscopy imaging in addition to standard ERCP devices and techniques. EUS-guided biliary drainage is an attractive option because of its minimally invasive, single step procedure which provides internal biliary decompression. Multiple investigators have reported high success and low complication rates. Unfortunately, high quality prospective data are still lacking. We provide detailed review of the use of EUS for biliary drainage from the perspective of practicing endoscopists with specific focus on the technical aspects of the procedure. PMID:22363114

Studies of uncontrolled air traffic patterns, phase 1

NASA Technical Reports Server (NTRS)

Baxa, E. G., Jr.; Scharf, L. L.; Ruedger, W. H.; Modi, J. A.; Wheelock, S. L.; Davis, C. M.

1975-01-01

The general aviation air traffic flow patterns at uncontrolled airports are investigated and analyzed and traffic pattern concepts are developed to minimize the midair collision hazard in uncontrolled airspace. An analytical approach to evaluate midair collision hazard probability as a function of traffic densities is established which is basically independent of path structure. Two methods of generating space-time interrelationships between terminal area aircraft are presented; one is a deterministic model to generate pseudorandom aircraft tracks, the other is a statistical model in preliminary form. Some hazard measures are presented for selected traffic densities. It is concluded that the probability of encountering a hazard should be minimized independently of any other considerations and that the number of encounters involving visible-avoidable aircraft should be maximized at the expense of encounters in other categories.

Minimizing makespan in a two-stage flow shop with parallel batch-processing machines and re-entrant jobs

NASA Astrophysics Data System (ADS)

Huang, J. D.; Liu, J. J.; Chen, Q. X.; Mao, N.

2017-06-01

Against a background of heat-treatment operations in mould manufacturing, a two-stage flow-shop scheduling problem is described for minimizing makespan with parallel batch-processing machines and re-entrant jobs. The weights and release dates of jobs are non-identical, but job processing times are equal. A mixed-integer linear programming model is developed and tested with small-scale scenarios. Given that the problem is NP hard, three heuristic construction methods with polynomial complexity are proposed. The worst case of the new constructive heuristic is analysed in detail. A method for computing lower bounds is proposed to test heuristic performance. Heuristic efficiency is tested with sets of scenarios. Compared with the two improved heuristics, the performance of the new constructive heuristic is superior.

Global optimization of multicomponent distillation configurations: 2. Enumeration based global minimization algorithm

DOE PAGES

Nallasivam, Ulaganathan; Shah, Vishesh H.; Shenvi, Anirudh A.; ...

2016-02-10

We present a general Global Minimization Algorithm (GMA) to identify basic or thermally coupled distillation configurations that require the least vapor duty under minimum reflux conditions for separating any ideal or near-ideal multicomponent mixture into a desired number of product streams. In this algorithm, global optimality is guaranteed by modeling the system using Underwood equations and reformulating the resulting constraints to bilinear inequalities. The speed of convergence to the globally optimal solution is increased by using appropriate feasibility and optimality based variable-range reduction techniques and by developing valid inequalities. As a result, the GMA can be coupled with already developedmore » techniques that enumerate basic and thermally coupled distillation configurations, to provide for the first time, a global optimization based rank-list of distillation configurations.« less

The equations of motion of a secularly precessing elliptical orbit

NASA Astrophysics Data System (ADS)

Casotto, S.; Bardella, M.

2013-01-01

The equations of motion of a secularly precessing ellipse are developed using time as the independent variable. The equations are useful when integrating numerically the perturbations about a reference trajectory which is subject to secular perturbations in the node, the argument of pericentre and the mean motion. Usually this is done in connection with Encke's method to ensure minimal rectification frequency. Similar equations are already available in the literature, but they are either given based on the true anomaly as the independent variable or in mixed mode with respect to time through the use of a supporting equation to track the anomaly. The equations developed here form a complete and independent set of six equations in time. Reformulations both of Escobal's and Kyner and Bennett's equations are also provided which lead to a more concise form.

Anatomic partial nephrectomy: technique evolution.

PubMed

Azhar, Raed A; Metcalfe, Charles; Gill, Inderbir S

2015-03-01

Partial nephrectomy provides equivalent long-term oncologic and superior functional outcomes as radical nephrectomy for T1a renal masses. Herein, we review the various vascular clamping techniques employed during minimally invasive partial nephrectomy, describe the evolution of our partial nephrectomy technique and provide an update on contemporary thinking about the impact of ischemia on renal function. Recently, partial nephrectomy surgical technique has shifted away from main artery clamping and towards minimizing/eliminating global renal ischemia during partial nephrectomy. Supported by high-fidelity three-dimensional imaging, novel anatomic-based partial nephrectomy techniques have recently been developed, wherein partial nephrectomy can now be performed with segmental, minimal or zero global ischemia to the renal remnant. Sequential innovations have included early unclamping, segmental clamping, super-selective clamping and now culminating in anatomic zero-ischemia surgery. By eliminating 'under-the-gun' time pressure of ischemia for the surgeon, these techniques allow an unhurried, tightly contoured tumour excision with point-specific sutured haemostasis. Recent data indicate that zero-ischemia partial nephrectomy may provide better functional outcomes by minimizing/eliminating global ischemia and preserving greater vascularized kidney volume. Contemporary partial nephrectomy includes a spectrum of surgical techniques ranging from conventional-clamped to novel zero-ischemia approaches. Technique selection should be tailored to each individual case on the basis of tumour characteristics, surgical feasibility, surgeon experience, patient demographics and baseline renal function.

Drug waste minimization as an effective strategy of cost-containment in Oncology

PubMed Central

2014-01-01

Background Sustainability of cancer care is a crucial issue for health care systems worldwide, even more during a time of economic recession. Low-cost measures are highly desirable to contain and reduce expenditures without impairing the quality of care. In this paper we aim to demonstrate the efficacy of drug waste minimization in reducing drug-related costs and its importance as a structural measure in health care management. Methods We first recorded intravenous cancer drugs prescription and amount of drug waste at the Oncology Department of Udine, Italy. Than we developed and applied a protocol for drug waste minimization based on per-pathology/per-drug scheduling of chemotherapies and pre-planned rounding of dosages. Results Before the protocol, drug wastage accounted for 8,3% of the Department annual drug expenditure. Over 70% of these costs were attributable to six drugs (cetuximab, docetaxel, gemcitabine, oxaliplatin, pemetrexed and trastuzumab) that we named ‘hot drugs’. Since the protocol introduction, we observed a 45% reduction in the drug waste expenditure. This benefit was confirmed in the following years and drug waste minimazion was able to limit the impact of new pricely drugs on the Department expenditures. Conclusions Facing current budgetary constraints, the application of a drug waste minimization model is effective in drug cost containment and may produce durable benefits. PMID:24507545

Developing and Implementing Monitoring and Evaluation Methods in the New Era of Expanded Care and Treatment of HIV/AIDS

ERIC Educational Resources Information Center

Wolf, R. Cameron; Bicego, George; Marconi, Katherine; Bessinger, Ruth; van Praag, Eric; Noriega-Minichiello, Shanti; Pappas, Gregory; Fronczak, Nancy; Peersman, Greet; Fiorentino, Renee K.; Rugg, Deborah; Novak, John

2004-01-01

The sharp rise in the HIV/AIDS burden worldwide has elicited calls for increased efforts to combat the spread and impact of HIV/AIDS. Efforts must continue with the aim to decrease new infections. At the same time, care and treatment services for those already infected can lead to longer, productive lives, thereby minimizing negative effects on…

The Validity of the Baby and Infant Screen for Children with aUtIsm Traits: Part 1 (BISCUIT-- Part 1)

ERIC Educational Resources Information Center

Matson, Johnny L.; Wilkins, Jonathan; Fodstad, Jill C.

2011-01-01

A top priority in the field of autism spectrum disorders (ASD) is the development of precise early diagnostic tools that can be completed with minimal time and training. We report on the convergent and divergent validity of the Baby and Infant Screen for Children with aUtIsm Traits (BISCUIT), specifically the BISCUIT-Part 1. Previous research with…

An Examination of the Evolution of Radiation and Advection Fogs

DTIC Science & Technology

1993-01-01

and fog diagnostic and prediction models have developed in sophistication so that they can reproduce fairly accurate one- or two-dimensional...occurred only by molecular diffusion near the interface created between the species during the mixing process. The rate of homogenization is minimal until...of excess vapor by molecular diffusion at the interfaces of nearly saturated air mixing in eddies is faster than the relaxation time of droplet

Biotechnology Research Requirements for Aeronautical Systems through the Year 2000. Volume 1

DTIC Science & Technology

1982-07-30

signature. Reducing the aero contain radic.?z,:"ve fallout. vehicle’s detectibility by reducing the optical, electro, acoustic, and infrared 0 Pulsed...arsenal devoted to agent doses. At this time, basic biochemical and chemical agents, reported use of mycotoxins and pharmacological data are minimal and...mass spectroscopy , quartz chemical agents must be developed. This research microbalances, Industrial hygiene dosimetry, damp should quantify human

Strategic Studies Quarterly. Volume 9, Number 3. Fall 2015

DTIC Science & Technology

2015-01-01

leaders doing what they can to better inform civilians to minimize the number of times civilian leaders might be wrong? Golby proposes a "new framework...but they have a clear responsibility to communicate their expertise and advice candidly during policy deliberations. The effective development of...there may not always be a clear distinction between political and military spheres. Political leaders of- ten depend on information they obtain from

Artificial Gravity for Mars Missions: The Different Design and Development Options

NASA Technical Reports Server (NTRS)

Murbach, Marcus; Arno, Roger D.

2000-01-01

One of the major impediments to human Mars missions is the development of appropriate countermeasures for long term physiological response to the micro-gravity environment. A plethora of countermeasure approaches have been advanced from strictly pharmacological measures to large diameter rotating spacecraft that would simulate a 1-g environment (the latter being the most conservative from a human health perspective). The different approaches have significantly different implications not only on the overall system design of a Mars Mission Vehicle (MMV) but on the necessary earth-orbiting platform that would be required to qualify the particular countermeasure system. it is found that these different design options can be conveniently categorized in terms of the order of magnitude of the rotation diameter required (100's, 10's, 1's, 0 meters). From this, the different mass penalties associated with each category can be generally compared. The overall objective of the countermeasure system should be to maximize crew safety and comfort, minimize exercise protocol time (i.e., the time per day that each crew member would have to participate in the exercise/countermeasure), maximize countermeasure effectiveness, and minimize the associated system mass penalty of the Mars Mission Vehicle (in terms of fraction of IMLEO - Injected Mass in Low Earth Orbit).

Thin film type 248-nm bottom antireflective coatings

NASA Astrophysics Data System (ADS)

Enomoto, Tomoyuki; Nakayama, Keisuke; Mizusawa, Kenichi; Nakajima, Yasuyuki; Yoon, Sangwoong; Kim, Yong-Hoon; Kim, Young-Ho; Chung, Hoesik; Chon, Sang Mun

2003-06-01

A frequent problem encountered by photoresists during the manufacturing of semiconductor device is that activating radiation is reflected back into the photoresist by the substrate. So, it is necessary that the light reflection is reduced from the substrate. One approach to reduce the light reflection is the use of bottom anti-reflective coating (BARC) applied to the substrate beneath the photoresist layer. The BARC technology has been utilized for a few years to minimize the reflectivity. As the chip size is reduced to sub 0.13-micron, the photoresist thickness has to decrease with the aspect ratio being less than 3.0. Therefore, new Organic BARC is strongly required which has the minimum reflectivity with thinner BARC thickness and higher etch selectivity towards resist. SAMSUNG Electronics has developed the advanced Organic BARC with Nissan Chemical Industries, Ltd. and Brewer Science, Inc. for achieving the above purpose. As a result, the suitable high performance SNAC2002 series KrF Organic BARCs were developed. Using CF4 gas as etchant, the plasma etch rate of SNAC2002 series is about 1.4 times higher than that of conventional KrF resists and 1.25 times higher than the existing product. The SNAC2002 series can minimize the substrate reflectivity at below 40nm BARC thickness, shows excellent litho performance and coating properties.

A lightweight distributed framework for computational offloading in mobile cloud computing.

PubMed

Shiraz, Muhammad; Gani, Abdullah; Ahmad, Raja Wasim; Adeel Ali Shah, Syed; Karim, Ahmad; Rahman, Zulkanain Abdul

2014-01-01

The latest developments in mobile computing technology have enabled intensive applications on the modern Smartphones. However, such applications are still constrained by limitations in processing potentials, storage capacity and battery lifetime of the Smart Mobile Devices (SMDs). Therefore, Mobile Cloud Computing (MCC) leverages the application processing services of computational clouds for mitigating resources limitations in SMDs. Currently, a number of computational offloading frameworks are proposed for MCC wherein the intensive components of the application are outsourced to computational clouds. Nevertheless, such frameworks focus on runtime partitioning of the application for computational offloading, which is time consuming and resources intensive. The resource constraint nature of SMDs require lightweight procedures for leveraging computational clouds. Therefore, this paper presents a lightweight framework which focuses on minimizing additional resources utilization in computational offloading for MCC. The framework employs features of centralized monitoring, high availability and on demand access services of computational clouds for computational offloading. As a result, the turnaround time and execution cost of the application are reduced. The framework is evaluated by testing prototype application in the real MCC environment. The lightweight nature of the proposed framework is validated by employing computational offloading for the proposed framework and the latest existing frameworks. Analysis shows that by employing the proposed framework for computational offloading, the size of data transmission is reduced by 91%, energy consumption cost is minimized by 81% and turnaround time of the application is decreased by 83.5% as compared to the existing offloading frameworks. Hence, the proposed framework minimizes additional resources utilization and therefore offers lightweight solution for computational offloading in MCC.

A Lightweight Distributed Framework for Computational Offloading in Mobile Cloud Computing

PubMed Central

Shiraz, Muhammad; Gani, Abdullah; Ahmad, Raja Wasim; Adeel Ali Shah, Syed; Karim, Ahmad; Rahman, Zulkanain Abdul

2014-01-01

The latest developments in mobile computing technology have enabled intensive applications on the modern Smartphones. However, such applications are still constrained by limitations in processing potentials, storage capacity and battery lifetime of the Smart Mobile Devices (SMDs). Therefore, Mobile Cloud Computing (MCC) leverages the application processing services of computational clouds for mitigating resources limitations in SMDs. Currently, a number of computational offloading frameworks are proposed for MCC wherein the intensive components of the application are outsourced to computational clouds. Nevertheless, such frameworks focus on runtime partitioning of the application for computational offloading, which is time consuming and resources intensive. The resource constraint nature of SMDs require lightweight procedures for leveraging computational clouds. Therefore, this paper presents a lightweight framework which focuses on minimizing additional resources utilization in computational offloading for MCC. The framework employs features of centralized monitoring, high availability and on demand access services of computational clouds for computational offloading. As a result, the turnaround time and execution cost of the application are reduced. The framework is evaluated by testing prototype application in the real MCC environment. The lightweight nature of the proposed framework is validated by employing computational offloading for the proposed framework and the latest existing frameworks. Analysis shows that by employing the proposed framework for computational offloading, the size of data transmission is reduced by 91%, energy consumption cost is minimized by 81% and turnaround time of the application is decreased by 83.5% as compared to the existing offloading frameworks. Hence, the proposed framework minimizes additional resources utilization and therefore offers lightweight solution for computational offloading in MCC. PMID:25127245

Insect Seed Predators in Erythrina falcata (Fabaceae): Identification of Predatory Species and Ecological Consequences of Asynchronous Flowering.

PubMed

Pereira, C M; Moura, M O; Da-Silva, P R

2014-06-01

Seed predation by insects exerts negative effects on plant reproduction by limiting the supply of seeds and preventing germination. Seed predators of the family Fabaceae are usually generalists, which increases the rate of predation. One strategy to minimize seed predation, developed by plants from temperate regions, is "escape in time," i.e., flowering before or after the peak of predation. For tropical species, few studies have investigated the strategies used by plants to minimize seed predation. Here, using Erythrina falcata, a tropical species of Fabaceae, we test three main hypotheses: (i) escape in time is a mechanism used by E. falcata to minimize seed predation, (ii) the predators of E. falcata seeds are generalists, and (iii) the biometric variables of the pods can influence seed predation. In order to test these hypotheses, we determined the flowering time of E. falcata, rate of seed predation, the predators insects, and biometric variables of the pods. The analyzed trees were grouped into three classes: "early," "peak," and "late" flowering. The average seed predation rates on trees in the early and late classes were 65% and 50%, respectively, and in the peak class, 80%; thus, our first hypothesis can be accepted. Three species of Lepidoptera and two of Coleoptera were found preying on E. falcata seeds. These species were observed to be generalist predators; thus, our second hypothesis can be accepted. The biometric variables of the pods cannot influence seed predation rate. The ecological consequences of asynchronous flowering on plants and insects are discussed.

Economic analysis of threatened species conservation: The case of woodland caribou and oilsands development in Alberta, Canada.

PubMed

Hauer, Grant; Vic Adamowicz, W L; Boutin, Stan

2018-07-15

Tradeoffs between cost and recovery targets for boreal caribou herds, threatened species in Alberta, Canada, are examined using a dynamic cost minimization model. Unlike most approaches used for minimizing costs of achieving threatened species targets, we incorporate opportunity costs of surface (forests) and subsurface resources (energy) as well as direct costs of conservation (habitat restoration and direct predator control), into a forward looking model of species protection. Opportunity costs of conservation over time are minimized with an explicit target date for meeting species recovery targets; defined as the number of self-sustaining caribou herds, which requires that both habitat and population targets are met by a set date. The model was run under various scenarios including three species recovery criteria, two oil and gas price regimes, and targets for the number of herds to recover from 1 to 12. The derived cost curve follows a typical pattern as costs of recovery per herd increase as the number of herds targeted for recovery increases. The results also show that the opportunity costs for direct predator control are small compared to habitat restoration and protection costs. However, direct predator control is essential for meeting caribou population targets and reducing the risk of extirpation while habitat is recovered over time. Copyright © 2018 Elsevier Ltd. All rights reserved.

Real-space finite-difference approach for multi-body systems: path-integral renormalization group method and direct energy minimization method.

PubMed

Sasaki, Akira; Kojo, Masashi; Hirose, Kikuji; Goto, Hidekazu

2011-11-02

The path-integral renormalization group and direct energy minimization method of practical first-principles electronic structure calculations for multi-body systems within the framework of the real-space finite-difference scheme are introduced. These two methods can handle higher dimensional systems with consideration of the correlation effect. Furthermore, they can be easily extended to the multicomponent quantum systems which contain more than two kinds of quantum particles. The key to the present methods is employing linear combinations of nonorthogonal Slater determinants (SDs) as multi-body wavefunctions. As one of the noticeable results, the same accuracy as the variational Monte Carlo method is achieved with a few SDs. This enables us to study the entire ground state consisting of electrons and nuclei without the need to use the Born-Oppenheimer approximation. Recent activities on methodological developments aiming towards practical calculations such as the implementation of auxiliary field for Coulombic interaction, the treatment of the kinetic operator in imaginary-time evolutions, the time-saving double-grid technique for bare-Coulomb atomic potentials and the optimization scheme for minimizing the total-energy functional are also introduced. As test examples, the total energy of the hydrogen molecule, the atomic configuration of the methylene and the electronic structures of two-dimensional quantum dots are calculated, and the accuracy, availability and possibility of the present methods are demonstrated.

Optimal control in adaptive optics modeling of nonlinear systems

NASA Astrophysics Data System (ADS)

Herrmann, J.

The problem of using an adaptive optics system to correct for nonlinear effects like thermal blooming is addressed using a model containing nonlinear lenses through which Gaussian beams are propagated. The best correction of this nonlinear system can be formulated as a deterministic open loop optimal control problem. This treatment gives a limit for the best possible correction. Aspects of adaptive control and servo systems are not included at this stage. An attempt is made to determine that control in the transmitter plane which minimizes the time averaged area or maximizes the fluence in the target plane. The standard minimization procedure leads to a two-point-boundary-value problem, which is ill-conditioned in the case. The optimal control problem was solved using an iterative gradient technique. An instantaneous correction is introduced and compared with the optimal correction. The results of the calculations show that for short times or weak nonlinearities the instantaneous correction is close to the optimal correction, but that for long times and strong nonlinearities a large difference develops between the two types of correction. For these cases the steady state correction becomes better than the instantaneous correction and approaches the optimum correction.

Control of an ER haptic master in a virtual slave environment for minimally invasive surgery applications

NASA Astrophysics Data System (ADS)

Han, Young-Min; Choi, Seung-Bok

2008-12-01

This paper presents the control performance of an electrorheological (ER) fluid-based haptic master device connected to a virtual slave environment that can be used for minimally invasive surgery (MIS). An already developed haptic joint featuring controllable ER fluid and a spherical joint mechanism is adopted for the master system. Medical forceps and an angular position measuring device are devised and integrated with the joint to establish the MIS master system. In order to embody a human organ in virtual space, a volumetric deformable object is used. The virtual object is then mathematically formulated by a shape-retaining chain-linked (S-chain) model. After evaluating the reflection force, computation time and compatibility with real-time control, the haptic architecture for MIS is established by incorporating the virtual slave with the master device so that the reflection force for the object of the virtual slave and the desired position for the master operator are transferred to each other. In order to achieve the desired force trajectories, a sliding mode controller is formulated and then experimentally realized. Tracking control performances for various force trajectories are evaluated and presented in the time domain.

Parameter estimation of kinetic models from metabolic profiles: two-phase dynamic decoupling method.

PubMed

Jia, Gengjie; Stephanopoulos, Gregory N; Gunawan, Rudiyanto

2011-07-15

Time-series measurements of metabolite concentration have become increasingly more common, providing data for building kinetic models of metabolic networks using ordinary differential equations (ODEs). In practice, however, such time-course data are usually incomplete and noisy, and the estimation of kinetic parameters from these data is challenging. Practical limitations due to data and computational aspects, such as solving stiff ODEs and finding global optimal solution to the estimation problem, give motivations to develop a new estimation procedure that can circumvent some of these constraints. In this work, an incremental and iterative parameter estimation method is proposed that combines and iterates between two estimation phases. One phase involves a decoupling method, in which a subset of model parameters that are associated with measured metabolites, are estimated using the minimization of slope errors. Another phase follows, in which the ODE model is solved one equation at a time and the remaining model parameters are obtained by minimizing concentration errors. The performance of this two-phase method was tested on a generic branched metabolic pathway and the glycolytic pathway of Lactococcus lactis. The results showed that the method is efficient in getting accurate parameter estimates, even when some information is missing.

Identifying Time Periods of Minimal Thermal Gradient for Temperature-Driven Structural Health Monitoring

PubMed Central

Reilly, John; Glisic, Branko

2018-01-01

Temperature changes play a large role in the day to day structural behavior of structures, but a smaller direct role in most contemporary Structural Health Monitoring (SHM) analyses. Temperature-Driven SHM will consider temperature as the principal driving force in SHM, relating a measurable input temperature to measurable output generalized strain (strain, curvature, etc.) and generalized displacement (deflection, rotation, etc.) to create three-dimensional signatures descriptive of the structural behavior. Identifying time periods of minimal thermal gradient provides the foundation for the formulation of the temperature–deformation–displacement model. Thermal gradients in a structure can cause curvature in multiple directions, as well as non-linear strain and stress distributions within the cross-sections, which significantly complicates data analysis and interpretation, distorts the signatures, and may lead to unreliable conclusions regarding structural behavior and condition. These adverse effects can be minimized if the signatures are evaluated at times when thermal gradients in the structure are minimal. This paper proposes two classes of methods based on the following two metrics: (i) the range of raw temperatures on the structure, and (ii) the distribution of the local thermal gradients, for identifying time periods of minimal thermal gradient on a structure with the ability to vary the tolerance of acceptable thermal gradients. The methods are tested and validated with data collected from the Streicker Bridge on campus at Princeton University. PMID:29494496

Identifying Time Periods of Minimal Thermal Gradient for Temperature-Driven Structural Health Monitoring.

PubMed

Reilly, John; Glisic, Branko

2018-03-01

Temperature changes play a large role in the day to day structural behavior of structures, but a smaller direct role in most contemporary Structural Health Monitoring (SHM) analyses. Temperature-Driven SHM will consider temperature as the principal driving force in SHM, relating a measurable input temperature to measurable output generalized strain (strain, curvature, etc.) and generalized displacement (deflection, rotation, etc.) to create three-dimensional signatures descriptive of the structural behavior. Identifying time periods of minimal thermal gradient provides the foundation for the formulation of the temperature-deformation-displacement model. Thermal gradients in a structure can cause curvature in multiple directions, as well as non-linear strain and stress distributions within the cross-sections, which significantly complicates data analysis and interpretation, distorts the signatures, and may lead to unreliable conclusions regarding structural behavior and condition. These adverse effects can be minimized if the signatures are evaluated at times when thermal gradients in the structure are minimal. This paper proposes two classes of methods based on the following two metrics: (i) the range of raw temperatures on the structure, and (ii) the distribution of the local thermal gradients, for identifying time periods of minimal thermal gradient on a structure with the ability to vary the tolerance of acceptable thermal gradients. The methods are tested and validated with data collected from the Streicker Bridge on campus at Princeton University.

Optimization Methods in Sherpa

NASA Astrophysics Data System (ADS)

Siemiginowska, Aneta; Nguyen, Dan T.; Doe, Stephen M.; Refsdal, Brian L.

2009-09-01

Forward fitting is a standard technique used to model X-ray data. A statistic, usually assumed weighted chi^2 or Poisson likelihood (e.g. Cash), is minimized in the fitting process to obtain a set of the best model parameters. Astronomical models often have complex forms with many parameters that can be correlated (e.g. an absorbed power law). Minimization is not trivial in such setting, as the statistical parameter space becomes multimodal and finding the global minimum is hard. Standard minimization algorithms can be found in many libraries of scientific functions, but they are usually focused on specific functions. However, Sherpa designed as general fitting and modeling application requires very robust optimization methods that can be applied to variety of astronomical data (X-ray spectra, images, timing, optical data etc.). We developed several optimization algorithms in Sherpa targeting a wide range of minimization problems. Two local minimization methods were built: Levenberg-Marquardt algorithm was obtained from MINPACK subroutine LMDIF and modified to achieve the required robustness; and Nelder-Mead simplex method has been implemented in-house based on variations of the algorithm described in the literature. A global search Monte-Carlo method has been implemented following a differential evolution algorithm presented by Storn and Price (1997). We will present the methods in Sherpa and discuss their usage cases. We will focus on the application to Chandra data showing both 1D and 2D examples. This work is supported by NASA contract NAS8-03060 (CXC).

Optimization of Highway Work Zone Decisions Considering Short-Term and Long-Term Impacts

DTIC Science & Technology

2010-01-01

strategies which can minimize the one-time work zone cost. Considering the complex and combinatorial nature of this optimization problem, a heuristic...combination of lane closure and traffic control strategies which can minimize the one-time work zone cost. Considering the complex and combinatorial nature ...zone) NV # the number of vehicle classes NPV $ Net Present Value p’(t) % Adjusted traffic diversion rate at time t p(t) % Natural diversion rate

Development of a Nonequilibrium Radiative Heating Prediction Method for Coupled Flowfield Solutions

NASA Technical Reports Server (NTRS)

Hartung, Lin C.

1991-01-01

A method for predicting radiative heating and coupling effects in nonequilibrium flow-fields has been developed. The method resolves atomic lines with a minimum number of spectral points, and treats molecular radiation using the smeared band approximation. To further minimize computational time, the calculation is performed on an optimized spectrum, which is computed for each flow condition to enhance spectral resolution. Additional time savings are obtained by performing the radiation calculation on a subgrid optimally selected for accuracy. Representative results from the new method are compared to previous work to demonstrate that the speedup does not cause a loss of accuracy and is sufficient to make coupled solutions practical. The method is found to be a useful tool for studies of nonequilibrium flows.

New minimally access hydrocelectomy.

PubMed

Saber, Aly

2011-02-01

To ascertain the acceptability of minimally access hydrocelectomy through a 2-cm incision and the outcome in terms of morbidity reduction and recurrence rate. Although controversy exists regarding the treatment of hydrocele, hydrocelectomy remains the treatment of choice for hydroceles. However, the standard surgical procedures for hydrocele can cause postoperative discomfort and complications. A total of 42 adult patients, aged 18-56 years, underwent hydrocelectomy as an outpatient procedure using a 2-cm scrotal skin incision and excision of only a small disk of the parietal tunica vaginalis. The operative time was 12-18 minutes (mean 15). The outcome measures included patient satisfaction and postoperative complications. This procedure requires minor dissection and minimal manipulation during treatment. It also resulted in no recurrence and minimal complications and required a short operative time. Copyright © 2011 Elsevier Inc. All rights reserved.

Osteoid osteoma of the mobile spine: surgical outcomes in 81 patients.

PubMed

Gasbarrini, Alessandro; Cappuccio, Michele; Bandiera, Stefano; Amendola, Luca; van Urk, Paul; Boriani, Stefano

2011-11-15

A restrospective review of 81 cases of osteoid osteoma of the mobile spine submitted to surgical treatment. Analyze pro and contras of different techniques (conventional and minimally invasive) for the treatment of osteoid osteoma. Intralesional excision has been considered the standard treatment for spinal osteoid osteoma. The high success rate of minimally invasive surgery in the treatment of a variety of spinal disorders lead us to believe this technique can also be applicable for the treatment of osteoid osteoma of the spine. Eighty-one patients affected by osteoid osteoma were consecutively treated by the same team with intralesional excision using conventional or minimally invasive approach by video-assisted endoscopy, microscope, or percutaneous radiofrequency coagulation. The clinical features, the radiologic findings, and the outcome were reviewed. Pain and neurologic symptoms, were scored before surgery, after surgery and at the follow-up. Complications and local recurrences were also recorded. Immediate relief of pain was observed after surgery in all patients. One patient showed mild neurologic impairment before treatment but became free of neurologic symptoms postoperative. Five local recurrences were found in four patients, always associated with pain. Three of these patients underwent surgery for a second time and one patient for a third time. There were two complications because surgery in two patients. One patient developed a pneumothorax, the other a hematoma. No related cases of kyphosis or scoliosis surgery were observed. Conventional excision therapy is a effective and reliable treatment for osteoid osteoma associated to low morbidity and low local recurrence rate. Minimally invasive surgery is emerging as an alternative method, reducing soft tissue trauma and the collateral damage caused by traditional surgical approach, allow patients a more rapid and complete return to normal function.

QRTEngine: An easy solution for running online reaction time experiments using Qualtrics.

PubMed

Barnhoorn, Jonathan S; Haasnoot, Erwin; Bocanegra, Bruno R; van Steenbergen, Henk

2015-12-01

Performing online behavioral research is gaining increased popularity among researchers in psychological and cognitive science. However, the currently available methods for conducting online reaction time experiments are often complicated and typically require advanced technical skills. In this article, we introduce the Qualtrics Reaction Time Engine (QRTEngine), an open-source JavaScript engine that can be embedded in the online survey development environment Qualtrics. The QRTEngine can be used to easily develop browser-based online reaction time experiments with accurate timing within current browser capabilities, and it requires only minimal programming skills. After introducing the QRTEngine, we briefly discuss how to create and distribute a Stroop task. Next, we describe a study in which we investigated the timing accuracy of the engine under different processor loads using external chronometry. Finally, we show that the QRTEngine can be used to reproduce classic behavioral effects in three reaction time paradigms: a Stroop task, an attentional blink task, and a masked-priming task. These findings demonstrate that QRTEngine can be used as a tool for conducting online behavioral research even when this requires accurate stimulus presentation times.

High-temperature thermal treatment of the uterus

NASA Astrophysics Data System (ADS)

Ryan, Thomas P.; Xiao, Jia Hua; Chung, Juh Yun

2003-06-01

More than 200,000 hysterectomies are performed annually in the US due to abnormal uterine bleeding from excessive menstrual flow. A minimally invasive procedure has been developed using thermal treatment combined with pressure to the endometrial lining of the uterus. Results from a 3-D finite element model will be shown, as well as experimental data. Good correlation was seen between simulations and experiments. The study found similar results then temperatures were increased and times for treatment were shortened.More than 200,000 hysterectomies are performed annually in the US due to abnormal uterine bleeding from excessive menstrual flow. A minimally invasive procedure has been developed using a balloon-based thermal treatment combined with pressure to the endometrial lining of the uterus. A 3D finite element model was set up to simulate the balloon ablation device in the human uterus as used in over 150,000 patients to date. Several additional simulations were made at higher temperatures to seek alternative combinations with higher temperature and shorter time intervals for the same depth of penetration, or deeper penetration at longer times and elevated temperatures. A temperature range of 87 to 150°C was explored. The Bioheat Equation was used in the simulations to predict temperature distributions in tissue. The Damage Integral was also used to characterize the location at depth of irreversible damage in the uterus. Treatment safety issues were also analyzed as the simulations showed the depth of penetration into the myometrium, towards the serosa.

Formulation strategy towards minimizing viscosity mediated negative food effect on disintegration and dissolution of immediate release tablets.

PubMed

Zaheer, Kamran; Langguth, Peter

2018-03-01

Food induced viscosity can delay disintegration and subsequent release of API from solid dosage form which may lead to severe reduction in the bioavailability of BCS type III compounds. Formulations of such tablets need to be optimized in view of this postprandial viscosity factor. In this study, three super disintegrants, croscarmellose sodium (CCS), cross-linked polyvinylpolypyrrolidone (CPD), and sodium starch glycolate (SSG) were assessed for their efficiency under simulated fed state. Tablets containing these disintegrants were compressed at 10 and 30 KN, while taking lactose as a soluble filler. In addition to other compendial tests, disintegration force of these formulations was measured by texture analysis. Comparison of parameters derived from force - time curves revealed a direct relation of maximum disintegration force (F max ) and disintegration force development rate (DFDR) with compressional force in fasted state, whereas an inverse relationship of F max and DFDR with compressional force was observed in fed state. The gelling tendency of disintegrants influenced the rate of release of API in simulated fed and fasted states when compressional force was changed. These observations recommend the evaluation of formulations in simulated fed state, in the development stage, with an objective of minimizing the negative impact of food induced viscosity on disintegration. Use of disintegrants that act without gelling or can counteract the effect of gelling is recommended for tablet formulations with reduced disintegration time (DT) and mean dissolution time (MDT) in fed state, respectively.

An Error-Entropy Minimization Algorithm for Tracking Control of Nonlinear Stochastic Systems with Non-Gaussian Variables

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Yunlong; Wang, Aiping; Guo, Lei

This paper presents an error-entropy minimization tracking control algorithm for a class of dynamic stochastic system. The system is represented by a set of time-varying discrete nonlinear equations with non-Gaussian stochastic input, where the statistical properties of stochastic input are unknown. By using Parzen windowing with Gaussian kernel to estimate the probability densities of errors, recursive algorithms are then proposed to design the controller such that the tracking error can be minimized. The performance of the error-entropy minimization criterion is compared with the mean-square-error minimization in the simulation results.

12 CFR 264b.4 - Gifts of minimal value.

Code of Federal Regulations, 2010 CFR

2010-01-01

... RULES REGARDING FOREIGN GIFTS AND DECORATIONS § 264b.4 Gifts of minimal value. (a) Board employees may... occur on the same day. (b) Board employees may determine at the time a gift is offered whether it is of... for valuation. (c) Disagreements over whether a gift is of minimal value will be resolved by an...

The development and application of a new tool to assess the adequacy of the content and timing of antenatal care

PubMed Central

2011-01-01

Background Current measures of antenatal care use are limited to initiation of care and number of visits. This study aimed to describe the development and application of a tool to assess the adequacy of the content and timing of antenatal care. Methods The Content and Timing of care in Pregnancy (CTP) tool was developed based on clinical relevance for ongoing antenatal care and recommendations in national and international guidelines. The tool reflects minimal care recommended in every pregnancy, regardless of parity or risk status. CTP measures timing of initiation of care, content of care (number of blood pressure readings, blood tests and ultrasound scans) and whether the interventions were received at an appropriate time. Antenatal care trajectories for 333 pregnant women were then described using a standard tool (the APNCU index), that measures the quantity of care only, and the new CTP tool. Both tools categorise care into 4 categories, from 'Inadequate' (both tools) to 'Adequate plus' (APNCU) or 'Appropriate' (CTP). Participants recorded the timing and content of their antenatal care prospectively using diaries. Analysis included an examination of similarities and differences in categorisation of care episodes between the tools. Results According to the CTP tool, the care trajectory of 10,2% of the women was classified as inadequate, 8,4% as intermediate, 36% as sufficient and 45,3% as appropriate. The assessment of quality of care differed significantly between the two tools. Seventeen care trajectories classified as 'Adequate' or 'Adequate plus' by the APNCU were deemed 'Inadequate' by the CTP. This suggests that, despite a high number of visits, these women did not receive the minimal recommended content and timing of care. Conclusions The CTP tool provides a more detailed assessment of the adequacy of antenatal care than the current standard index. However, guidelines for the content of antenatal care vary, and the tool does not at the moment grade over-use of interventions as 'Inappropriate'. Further work needs to be done to refine the content items prior to larger scale testing of the impact of the new measure. PMID:21896201

Laparoscopic revolution in bariatric surgery

PubMed Central

Sundbom, Magnus

2014-01-01

The history of bariatric surgery is investigational. Dedicated surgeons have continuously sought for an ideal procedure to relieve morbidly obese patients from their burden of comorbid conditions, reduced life expectancy and low quality of life. The ideal procedure must have low complication risk, both in short- and long term, as well as minimal impact on daily life. The revolution of laparoscopic techniques in bariatric surgery is described in this summary. Advances in minimal invasive techniques have contributed to reduced operative time, length of stay, and complications. The development in bariatric surgery has been exceptional, resulting in a dramatic increase of the number of procedures performed world wide during the last decades. Although, a complex bariatric procedure can be performed with operative mortality no greater than cholecystectomy, specific procedure-related complications and other drawbacks must be taken into account. The evolution of laparoscopy will be the legacy of the 21st century and at present, day-care surgery and further reduction of the operative trauma is in focus. The impressive effects on comorbid conditions have prompted the adoption of minimal invasive bariatric procedures into the field of metabolic surgery. PMID:25386062

Trace metal release after minimally-invasive repair of pectus excavatum.

PubMed

Fortmann, Caroline; Göen, Thomas; Krüger, Marcus; Ure, Benno M; Petersen, Claus; Kübler, Joachim F

2017-01-01

Several studies have shown a high incidence of metal allergy after minimally-invasive repair of pectus excavatum (MIRPE). We postulated that MIRPE is associated with a significant release of trace metal ions, possibly causing the allergic symptoms. We evaluated the concentration with chromium, cobalt and nickel in blood, urine and tissue in patients prior to MIRPE and in patients who underwent an explantation of the stainless-steel bar(s) after three years. Our study group consisted of 20 patients (mean age 19 years) who had bar explantation and our control group included 20 patients (mean age 16 years) prior to MIRPE. At the time of bar removal we detected significantly elevated concentrations of chromium and nickel in the tissue compared to patients prior to the procedure (p<0,001). We also found a significant increase in the levels of chromium in urine and nickel in blood in patients three years post MIRPE (p<0,001). Four patients temporarily developed symptoms of metal allergy, all had elevated metal values in blood and urine at explantation. Minimally-invasive repair of pectus excavatum can lead to a significant trace metal exposure.

Hessian-based norm regularization for image restoration with biomedical applications.

PubMed

Lefkimmiatis, Stamatios; Bourquard, Aurélien; Unser, Michael

2012-03-01

We present nonquadratic Hessian-based regularization methods that can be effectively used for image restoration problems in a variational framework. Motivated by the great success of the total-variation (TV) functional, we extend it to also include second-order differential operators. Specifically, we derive second-order regularizers that involve matrix norms of the Hessian operator. The definition of these functionals is based on an alternative interpretation of TV that relies on mixed norms of directional derivatives. We show that the resulting regularizers retain some of the most favorable properties of TV, i.e., convexity, homogeneity, rotation, and translation invariance, while dealing effectively with the staircase effect. We further develop an efficient minimization scheme for the corresponding objective functions. The proposed algorithm is of the iteratively reweighted least-square type and results from a majorization-minimization approach. It relies on a problem-specific preconditioned conjugate gradient method, which makes the overall minimization scheme very attractive since it can be applied effectively to large images in a reasonable computational time. We validate the overall proposed regularization framework through deblurring experiments under additive Gaussian noise on standard and biomedical images.

Gimbal Control Algorithms for the Global Precipitation Measurement Core Observatory

NASA Technical Reports Server (NTRS)

Welter, Gary L.; Liu, Kuo Chia; Blaurock, Carl

2012-01-01

There are two gimbaled systems on the Global Precipitation Measurement Core Observatory: two single-degree-of-freedom solar arrays (SAs) and one two-degree-of-freedom high gain antenna (HGA). The guidance, navigation, and control analysis team was presented with the following challenges regarding SA orientation control during periods of normal mission science: (1) maximize solar flux on the SAs during orbit day, subject to battery charging limits, (2) minimize atmospheric drag during orbit night to reduce frequency of orbit maintenance thruster usage, (3) minimize atmospheric drag during orbits for which solar flux is nearly independent of SA orientation, and (4) keep array-induced spacecraft attitude disturbances within allocated tolerances. The team was presented with the following challenges regarding HGA control during mission science periods: (1) while tracking a ground-selected Tracking Data and Relay Satellite (TDRS), keep HGA control error below about 4', (2) keep array-induced spacecraft attitude disturbances small, and (3) minimize transition time between TDRSs subject to constraints imposed by item 2. This paper describes the control algorithms developed to achieve these goals and certain analysis done as part of that work.

Development of sinkholes resulting from man's activities in the Eastern United States

USGS Publications Warehouse

Newton, John G.

1987-01-01

Alternatives that allow avoiding or minimizing sinkhole hazards are most numerous when a problem or potential problem is recognized during site evaluation. The number of alternatives declines after the beginning of site development. Where sinkhole development is predictable, zoning of land use can minimize hazards.

The threshold algorithm: Description of the methodology and new developments

NASA Astrophysics Data System (ADS)

Neelamraju, Sridhar; Oligschleger, Christina; Schön, J. Christian

2017-10-01

Understanding the dynamics of complex systems requires the investigation of their energy landscape. In particular, the flow of probability on such landscapes is a central feature in visualizing the time evolution of complex systems. To obtain such flows, and the concomitant stable states of the systems and the generalized barriers among them, the threshold algorithm has been developed. Here, we describe the methodology of this approach starting from the fundamental concepts in complex energy landscapes and present recent new developments, the threshold-minimization algorithm and the molecular dynamics threshold algorithm. For applications of these new algorithms, we draw on landscape studies of three disaccharide molecules: lactose, maltose, and sucrose.

Airline Operations Aid

NASA Technical Reports Server (NTRS)

1993-01-01

C Language Integrated Production System (CLIPS), a NASA-developed expert systems program, is used by American Airlines for three purposes: as a rapid prototyping tool; to develop production prototypes; and to develop production application. An example of the latter is CLIPS' use in "Hub S1AAshing," a knowledge based system that recommends contingency plans when severe schedule reductions must be made. Hub S1AAshing has replaced a manual, labor intensive process. It saves time and allows Operations Control Coordinators to handle more difficult situations. Because the system assimilates much of the information necessary to facilitate educated decision making, it minimizes negative impact in situations where it is impossible to operate all flights.

Digital pulse processing for planar TlBr detectors, optimized for ballistic deficit and charge-trapping effect

NASA Astrophysics Data System (ADS)

Nakhostin, M.; Hitomi, K.

2012-05-01

The energy resolution of thallium bromide (TlBr) detectors is significantly limited by charge-trapping effect and pulse ballistic deficit, caused by the slow charge collection time. A digital pulse processing algorithm has been developed aiming to compensate for charge-trapping effect, while minimizing pulse ballistic deficit. The algorithm is examined using a 1 mm thick TlBr detector and an excellent energy resolution of 3.37% at 662 keV is achieved at room temperature. The pulse processing algorithms are presented in recursive form, suitable for real-time implementations.

Multiple Fault Isolation in Redundant Systems

NASA Technical Reports Server (NTRS)

Pattipati, Krishna R.; Patterson-Hine, Ann; Iverson, David

1997-01-01

Fault diagnosis in large-scale systems that are products of modern technology present formidable challenges to manufacturers and users. This is due to large number of failure sources in such systems and the need to quickly isolate and rectify failures with minimal down time. In addition, for fault-tolerant systems and systems with infrequent opportunity for maintenance (e.g., Hubble telescope, space station), the assumption of at most a single fault in the system is unrealistic. In this project, we have developed novel block and sequential diagnostic strategies to isolate multiple faults in the shortest possible time without making the unrealistic single fault assumption.

Multiple Fault Isolation in Redundant Systems

NASA Technical Reports Server (NTRS)

Pattipati, Krishna R.

1997-01-01

Fault diagnosis in large-scale systems that are products of modem technology present formidable challenges to manufacturers and users. This is due to large number of failure sources in such systems and the need to quickly isolate and rectify failures with minimal down time. In addition, for fault-tolerant systems and systems with infrequent opportunity for maintenance (e.g., Hubble telescope, space station), the assumption of at most a single fault in the system is unrealistic. In this project, we have developed novel block and sequential diagnostic strategies to isolate multiple faults in the shortest possible time without making the unrealistic single fault assumption.

A highly manufacturable 0.2 {mu}m AlGaAs/InGaAs PHEMT fabricated using the single-layer integrated-metal FET (SLIMFET) process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Havasy, C.K.; Quach, T.K.; Bozada, C.A.

1995-12-31

This work is the development of a single-layer integrated-metal field effect transistor (SLIMFET) process for a high performance 0.2 {mu}m AlGaAs/InGaAs pseudomorphic high electron mobility transistor (PHEMT). This process is compatible with MMIC fabrication and minimizes process variations, cycle time, and cost. This process uses non-alloyed ohmic contacts, a selective gate-recess etching process, and a single gate/source/drain metal deposition step to form both Schottky and ohmic contacts at the same time.

An Optical Lever For The Metrology Of Grazing Incidence Optics

NASA Astrophysics Data System (ADS)

DeCew, Alan E.; Wagner, Robert W.

1986-11-01

Research Optics & Development, Inc. is using a slope tracing profilometer to measure the figure of optical surfaces which cannot be measured conveniently by interferometric means. As a metrological tool, the technique has its greatest advantage as an in-process easurement system. An optician can easily convert from polishing to measurement in less than a minute of time. This rapid feedback allows figure correction with minimal wasted effort and setup time. The present configuration of the slope scanner provides resolutions to 1 micro-radian. By implementing minor modifications, the resolution could be improved by an order of magnitude.

Disciplined rubidium oscillator with GPS selective availability

NASA Technical Reports Server (NTRS)

Dewey, Wayne P.

1993-01-01

A U.S. Department of Defense decision for continuous implementation of GPS Selective Availability (S/A) has made it necessary to modify Rubidium oscillator disciplining methods. One such method for reducing the effects of S/A on the oscillator disciplining process was developed which achieves results approaching pre-S/A GPS. The Satellite Hopping algorithm used in minimizing the effects of S/A on the oscillator disciplining process is described, and the results of using this process to those obtained prior to the implementation of S/A are compared. Test results are from a TrueTime Rubidium based Model GPS-DC timing receiver.

Advanced Decontamination Technologies: High Hydrostatic Pressure on Meat Products

NASA Astrophysics Data System (ADS)

Garriga, Margarita; Aymerich, Teresa

The increasing demand for “natural” foodstuffs, free from chemical additives, and preservatives has triggered novel approaches in food technology developments. In the last decade, practical use of high-pressure processing (HPP) made this emerging non-thermal technology very attractive from a commercial point of view. Despite the fact that the investment is still high, the resulting value-added products, with an extended and safe shelf-life, will fulfil the wishes of consumers who prefer preservative-free minimally processed foods, retaining sensorial characteristics of freshness. Moreover, unlike thermal treatment, pressure treatment is not time/mass dependant, thus reducing the time of processing.

Maintaining oncologic integrity with minimally invasive resection of pediatric embryonal tumors.

PubMed

Phelps, Hannah M; Ayers, Gregory D; Ndolo, Josephine M; Dietrich, Hannah L; Watson, Katherine D; Hilmes, Melissa A; Lovvorn, Harold N

2018-05-08

Embryonal tumors arise typically in infants and young children and are often massive at presentation. Operative resection is a cornerstone in the multimodal treatment of embryonal tumors but potentially disrupts therapeutic timelines. When used appropriately, minimally invasive surgery can minimize treatment delays. The oncologic integrity and safety attainable with minimally invasive resection of embryonal tumors, however, remains controversial. Query of the Vanderbilt Cancer Registry identified all children treated for intracavitary, embryonal tumors during a 15-year period. Tumors were assessed radiographically to measure volume (mL) and image-defined risk factors (neuroblastic tumors only) at time of diagnosis, and at preresection and postresection. Patient and tumor characteristics, perioperative details, and oncologic outcomes were compared between minimally invasive surgery and open resection of tumors of comparable size. A total of 202 patients were treated for 206 intracavitary embryonal tumors, of which 178 were resected either open (n = 152, 85%) or with minimally invasive surgery (n = 26, 15%). The 5-year, relapse-free, and overall survival were not significantly different after minimally invasive surgery or open resection of tumors having a volume less than 100 mL, corresponding to the largest resected with minimally invasive surgery (P = .249 and P = .124, respectively). No difference in margin status or lymph node sampling between the 2 operative approaches was detected (p = .333 and p = .070, respectively). Advantages associated with minimally invasive surgery were decreased blood loss (P < .001), decreased operating time (P = .002), and shorter hospital stay (P < .001). Characteristically, minimally invasive surgery was used for smaller volume and earlier stage neuroblastic tumors without image-defined risk factors. When selected appropriately, minimally invasive resection of pediatric embryonal tumors, particularly neuroblastic tumors, provides acceptable oncologic integrity. Large tumor volume, small patient size, and image-defined risk factors may limit the broader applicability of minimally invasive surgery. Copyright © 2018 Elsevier Inc. All rights reserved.

Application-oriented offloading in heterogeneous networks for mobile cloud computing

NASA Astrophysics Data System (ADS)

Tseng, Fan-Hsun; Cho, Hsin-Hung; Chang, Kai-Di; Li, Jheng-Cong; Shih, Timothy K.

2018-04-01

Nowadays Internet applications have become more complicated that mobile device needs more computing resources for shorter execution time but it is restricted to limited battery capacity. Mobile cloud computing (MCC) is emerged to tackle the finite resource problem of mobile device. MCC offloads the tasks and jobs of mobile devices to cloud and fog environments by using offloading scheme. It is vital to MCC that which task should be offloaded and how to offload efficiently. In the paper, we formulate the offloading problem between mobile device and cloud data center and propose two algorithms based on application-oriented for minimum execution time, i.e. the Minimum Offloading Time for Mobile device (MOTM) algorithm and the Minimum Execution Time for Cloud data center (METC) algorithm. The MOTM algorithm minimizes offloading time by selecting appropriate offloading links based on application categories. The METC algorithm minimizes execution time in cloud data center by selecting virtual and physical machines with corresponding resource requirements of applications. Simulation results show that the proposed mechanism not only minimizes total execution time for mobile devices but also decreases their energy consumption.

How successful are mutants in multiplayer games with fluctuating environments? Sojourn times, fixation and optimal switching

PubMed Central

Galla, Tobias

2018-01-01

Using a stochastic model, we investigate the probability of fixation, and the average time taken to achieve fixation, of a mutant in a population of wild-types. We do this in a context where the environment in which the competition takes place is subject to stochastic change. Our model takes into account interactions which can involve multiple participants. That is, the participants take part in multiplayer games. We find that under certain circumstances, there are environmental switching dynamics which minimize the time that it takes for the mutants to fixate. To analyse the dynamics more closely, we develop a method by which to calculate the sojourn times for general birth–death processes in fluctuating environments. PMID:29657810

How successful are mutants in multiplayer games with fluctuating environments? Sojourn times, fixation and optimal switching

NASA Astrophysics Data System (ADS)

Baron, Joseph W.; Galla, Tobias

2018-03-01

Using a stochastic model, we investigate the probability of fixation, and the average time taken to achieve fixation, of a mutant in a population of wild-types. We do this in a context where the environment in which the competition takes place is subject to stochastic change. Our model takes into account interactions which can involve multiple participants. That is, the participants take part in multiplayer games. We find that under certain circumstances, there are environmental switching dynamics which minimize the time that it takes for the mutants to fixate. To analyse the dynamics more closely, we develop a method by which to calculate the sojourn times for general birth-death processes in fluctuating environments.

Aerial Refueling Process Rescheduling Under Job Related Disruptions

NASA Technical Reports Server (NTRS)

Kaplan, Sezgin; Rabadi, Ghaith

2011-01-01

The Aerial Refueling Scheduling Problem (ARSP) can be defined as determining the refueling completion times for each fighter aircraft (job) on the multiple tankers (machines) to minimize the total weighted tardiness. ARSP assumes that the jobs have different release times and due dates. The ARSP is dynamic environment and unexpected events may occur. In this paper, rescheduling in the aerial refueling process with a time set of jobs will be studied to deal with job related disruptions such as the arrival of new jobs, the departure of an existing job, high deviations in the release times and changes in job priorities. In order to keep the stability and to avoid excessive computation, partial schedule repair algorithm is developed and its preliminary results are presented.

Real-Time Aerodynamic Flow and Data Visualization in an Interactive Virtual Environment

NASA Technical Reports Server (NTRS)

Schwartz, Richard J.; Fleming, Gary A.

2005-01-01

Significant advances have been made to non-intrusive flow field diagnostics in the past decade. Camera based techniques are now capable of determining physical qualities such as surface deformation, surface pressure and temperature, flow velocities, and molecular species concentration. In each case, extracting the pertinent information from the large volume of acquired data requires powerful and efficient data visualization tools. The additional requirement for real time visualization is fueled by an increased emphasis on minimizing test time in expensive facilities. This paper will address a capability titled LiveView3D, which is the first step in the development phase of an in depth, real time data visualization and analysis tool for use in aerospace testing facilities.

Low Cost Manufacturing Approach of High Temperature PMC Components

NASA Technical Reports Server (NTRS)

Kannmacher, Kevin

1997-01-01

The overall objective is to develop a satisfactory sheet molding compound (SMC) of a high temperature polyimide, such as PMR-11-50, VCAP-75, or NB2-76, and to develop compression molding processing parameters for a random, chopped fiber, high temperature, sheet molding compound that will be more affordable than the traditional hand lay-up fabrication methods. Compression molding will reduce manufacturing costs of composites by: (1) minimizing the conventional machining required after fabrication due to the use of full 360 deg matched tooling, (2) reducing fabrication time by minimizing the intensive hand lay-up operations associated with individual ply fabrication techniques, such as ply orientation and ply count and (3) possibly reducing component mold time by advanced B-staging prior to molding. This program is an integral part of Allison's T406/AE engine family's growth plan, which will utilize technologies developed under NASA's Sub-sonic Transport (AST) programs, UHPTET initiatives, and internally through Allison's IR&D projects. Allison is aggressively pursuing this next generation of engines, with both commercial and military applications, by reducing the overall weight of the engine through the incorporation of advanced, lightweight, high temperature materials, such as polymer matrix composites. This infusion of new materials into the engine is also a major factor in reducing engine cost because it permits the use of physically smaller structural components to achieve the same thrust levels as the generation that it replaced. A lighter, more efficient propulsion system translates to a substantial cost and weight savings to an airframe's structure.

Leyla loop: a time-saving suture technique for robotic atrial closure

PubMed Central

Kılıç, Leyla; Şenay, Şahin; Ümit Güllü, A.; Alhan, Cem

2013-01-01

The longer durations of cardiopulmonary bypass and aortic cross-clamp times remain the disadvantages of robotic or minimally invasive cardiac surgery. For this reason, every small contribution to speeding up these procedures is of the utmost importance. Here, we present a practical, easy and time-saving suture technique for atrial closure. It consists of a hand-made loop at one end of the suture and saves the time otherwise consumed by knotting. It may also be used during conventional or minimally invasive cardiac surgery. PMID:23760357

Minimizing the effect of process mismatch in a neuromorphic system using spike-timing-dependent adaptation.

PubMed

Cameron, Katherine; Murray, Alan

2008-05-01

This paper investigates whether spike-timing-dependent plasticity (STDP) can minimize the effect of mismatch within the context of a depth-from-motion algorithm. To improve noise rejection, this algorithm contains a spike prediction element, whose performance is degraded by analog very large scale integration (VLSI) mismatch. The error between the actual spike arrival time and the prediction is used as the input to an STDP circuit, to improve future predictions. Before STDP adaptation, the error reflects the degree of mismatch within the prediction circuitry. After STDP adaptation, the error indicates to what extent the adaptive circuitry can minimize the effect of transistor mismatch. The circuitry is tested with static and varying prediction times and chip results are presented. The effect of noisy spikes is also investigated. Under all conditions the STDP adaptation is shown to improve performance.

Hierarchical planning for a surface mounting machine placement.

PubMed

Zeng, You-jiao; Ma, Deng-ze; Jin, Ye; Yan, Jun-qi

2004-11-01

For a surface mounting machine (SMM) in printed circuit board (PCB) assembly line, there are four problems, e.g. CAD data conversion, nozzle selection, feeder assignment and placement sequence determination. A hierarchical planning for them to maximize the throughput rate of an SMM is presented here. To minimize set-up time, a CAD data conversion system was first applied that could automatically generate the data for machine placement from CAD design data files. Then an effective nozzle selection approach implemented to minimize the time of nozzle changing. And then, to minimize picking time, an algorithm for feeder assignment was used to make picking multiple components simultaneously as much as possible. Finally, in order to shorten pick-and-place time, a heuristic algorithm was used to determine optimal component placement sequence according to the decided feeder positions. Experiments were conducted on a four head SMM. The experimental results were used to analyse the assembly line performance.

X-ray beam equalization for digital fluoroscopy

NASA Astrophysics Data System (ADS)

Molloi, Sabee Y.; Tang, Jerry; Marcin, Martin R.; Zhou, Yifang; Anvar, Behzad

1996-04-01

The concept of radiographic equalization has previously been investigated. However, a suitable technique for digital fluoroscopic applications has not been developed. The previously reported scanning equalization techniques cannot be applied to fluoroscopic applications due to their exposure time limitations. On the other hand, area beam equalization techniques are more suited for digital fluoroscopic applications. The purpose of this study is to develop an x- ray beam equalization technique for digital fluoroscopic applications that will produce an equalized radiograph with minimal image artifacts and tube loading. Preliminary unequalized images of a humanoid chest phantom were acquired using a digital fluoroscopic system. Using this preliminary image as a guide, an 8 by 8 array of square pistons were used to generate masks in a mold with CeO2. The CeO2 attenuator thicknesses were calculated using the gray level information from the unequalized image. The generated mask was positioned close to the focal spot (magnification of 8.0) in order to minimize edge artifacts from the mask. The masks were generated manually in order to investigate the piston and matrix size requirements. The development of an automated version of mask generation and positioning is in progress. The results of manual mask generation and positioning show that it is possible to generate equalized radiographs with minimal perceptible artifacts. The equalization of x-ray transmission across the field exiting from the object significantly improved the image quality by preserving local contrast throughout the image. Furthermore, the reduction in dynamic range significantly reduced the effect of x-ray scatter and veiling glare from high transmission to low transmission areas. Also, the x-ray tube loading due to the mask assembly itself was negligible. In conclusion it is possible to produce area beam compensation that will be compatible with digital fluoroscopy with minimal compensation artifacts. The compensation process produces an image with equalized signal to noise ratio in all parts of the image.

A Tool for the Automated Design and Evaluation of Habitat Interior Layouts

NASA Technical Reports Server (NTRS)

Simon, Matthew A.; Wilhite, Alan W.

2013-01-01

The objective of space habitat design is to minimize mass and system size while providing adequate space for all necessary equipment and a functional layout that supports crew health and productivity. Unfortunately, development and evaluation of interior layouts is often ignored during conceptual design because of the subjectivity and long times required using current evaluation methods (e.g., human-in-the-loop mockup tests and in-depth CAD evaluations). Early, more objective assessment could prevent expensive design changes that may increase vehicle mass and compromise functionality. This paper describes a new interior design evaluation method to enable early, structured consideration of habitat interior layouts. This interior layout evaluation method features a comprehensive list of quantifiable habitat layout evaluation criteria, automatic methods to measure these criteria from a geometry model, and application of systems engineering tools and numerical methods to construct a multi-objective value function measuring the overall habitat layout performance. In addition to a detailed description of this method, a C++/OpenGL software tool which has been developed to implement this method is also discussed. This tool leverages geometry modeling coupled with collision detection techniques to identify favorable layouts subject to multiple constraints and objectives (e.g., minimize mass, maximize contiguous habitable volume, maximize task performance, and minimize crew safety risks). Finally, a few habitat layout evaluation examples are described to demonstrate the effectiveness of this method and tool to influence habitat design.

Towards understanding KOH conditioning of amidoxime-based polymer adsorbents for sequestering uranium from seawater

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pan, Horng-Bin; Kuo, Li-Jung; Wood, Jordana

2015-01-01

Conditioning of polymer fiber adsorbents grafted with amidoxime and carboxylic acid groups is necessary to make the materials hydrophilic for sequestering uranium from seawater. Spectroscopic techniques were employed to study the effectiveness of the traditional KOH conditioning method (2.5% KOH at 80 oC) on recently developed high-surface-area amidoxime-based polymer fiber adsorbents developed at Oak Ridge National Laboratory. FTIR spectra reveal that the KOH conditioning process removes the proton from the carboxylic acids and also converts the amidoxime groups to carboxylate groups in the adsorbent. With prolonged KOH treatment (>1 hr) at 80 oC, physical damage to the adsorbent material occursmore » which can lead to a significant reduction in the adsorbent’s uranium adsorption capability in real seawater during extended exposure times (>21 days). The physical damage to the adsorbent can be minimized by lowering KOH conditioning temperature. For the high-surface-area amidoxime-based adsorbents, 20 min of conditioning in 2.5% KOH at 80 oC or 1 hr of conditioning in 2.5% KOH at 60 oC appears sufficient to achieve de-protonation of the carboxylic acid with minimal harmful effects to the adsorbent material. The use of NaOH instead of KOH can also reduce the cost of the base treatment process required for conditioning the amidoxime-based sorbents with minimal loss of adsorption capacity (≤ 7%).« less

Array of Bolometers for Submillimeter- Wavelength Operation

NASA Technical Reports Server (NTRS)

Bock, James; Turner, Anthony

2007-01-01

A feed-horn-coupled monolithic array of micromesh bolometers is undergoing development for use in a photometric camera. The array is designed for conducting astrophysical observations in a wavelength band centered at 350 m. The bolometers are improved versions of previously developed bolometers comprising metalized Si3N4 micromesh radiation absorbers coupled with neutron- transmutation-doped Ge thermistors. Incident radiation heats the absorbers above a base temperature, changing the electrical resistance of each thermistor. In the present array of improved bolometers (see figure), the thermistors are attached to the micromesh absorbers by indium bump bonds and are addressed by use of lithographed, vapor-deposited electrical leads. This architecture reduces the heat capacity and minimizes the thermal conductivity to 1/20 and 1/300, respectively, of earlier versions of these detectors, with consequent improvement in sensitivity and speed of response. The micromesh bolometers, intended to operate under an optical background set by thermal emission from an ambient-temperature space-borne telescope, are designed such that the random arrival of photons ("photon noise") dominates the noise sources arising from the detector and readout electronics. The micromesh is designed to be a highly thermally and optically efficient absorber with a limiting response time of about 100 s. The absorber and thermistor heat capacity are minimized in order to give rapid speed of response. Due to the minimization of the absorber volume, the dominant source of heat capacity arises from the thermistor.

Validation of the United States Marine Corps Qualified Candidate Population Model

DTIC Science & Technology

2003-03-01

time. Fields are created in the database to support this forecasting. User forms and a macro are programmed in Microsoft VBA to develop the...at 0.001. To accomplish 50,000 iterations of a minimization problem, this study wrote a macro in the VBA programming language that guides the solver...success in the commissioning process. **To improve the diagnostics of this propensity model, other factors were considered as well. Applying SQL

Laboratory Evaluation of Expedient Low-Temperature Concrete Admixtures for Repairing Blast Holes in Cold Weather

DTIC Science & Technology

2013-01-08

This re- search ignores effects on long-term durability, trafficability, temperature rebar corrosion , and other concerns that are of minimal... concrete because it can cause corrosion of steel reinforcement. However, the corrosion problem develops slowly with time; therefore, this problem has a...ER D C/ CR RE L TR -1 3- 1 Laboratory Evaluation of Expedient Low- Temperature Concrete Admixtures for Repairing Blast Holes in Cold

Glass ionomer-silver cermet Class II tunnel-restorations for primary molars.

PubMed

Croll, T P

1988-01-01

Tunnel preparations preserve the anatomical marginal ridge and minimize the loss of healthy tooth structure adjacent to the carious lesion. When the practitioner has developed proficiency in restoring class II carious lesions with tunnel restorations, less treatment time is required than with traditional class II preparations. The technique for restoring a primary first molar with a class II carious lesion, using a tunnel preparation and Ketac-Silver restorative material is described.

Performance of an 8 kW Hall Thruster

DTIC Science & Technology

2000-01-12

For the purpose of either orbit raising and/or repositioning the Hall thruster must be capable of delivering sufficient thrust to minimize transfer...time. This coupled with the increasing on-board electric power capacity of military and commercial satellites, requires a high power Hall thruster that...development of a novel, high power Hall thruster , capable of efficient operation over a broad range of Isp and thrust. We call such a thruster the bi

Minimizing Security Forces Response Times Through the Use of Facility Location Methodologies

DTIC Science & Technology

2005-03-01

etc. In his book Network and Discrete Location: Models, Algorithms, and Applications author Mark S. Daskin provides a comprehensive introduction to...the art and science of locating facilities. ( Daskin , 1995) The book espouses to be a hands-on guide to using and developing facility location models...method used in this research is from Daskin (1995). The formulation presented by Daskin includes a multiplicative weighting factor for the amount

AEGIS: a robust and scalable real-time public health surveillance system.

PubMed

Reis, Ben Y; Kirby, Chaim; Hadden, Lucy E; Olson, Karen; McMurry, Andrew J; Daniel, James B; Mandl, Kenneth D

2007-01-01

In this report, we describe the Automated Epidemiological Geotemporal Integrated Surveillance system (AEGIS), developed for real-time population health monitoring in the state of Massachusetts. AEGIS provides public health personnel with automated near-real-time situational awareness of utilization patterns at participating healthcare institutions, supporting surveillance of bioterrorism and naturally occurring outbreaks. As real-time public health surveillance systems become integrated into regional and national surveillance initiatives, the challenges of scalability, robustness, and data security become increasingly prominent. A modular and fault tolerant design helps AEGIS achieve scalability and robustness, while a distributed storage model with local autonomy helps to minimize risk of unauthorized disclosure. The report includes a description of the evolution of the design over time in response to the challenges of a regional and national integration environment.

Minimizing damage to a propped fracture by controlled flowback procedures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robinson, B.M.; Holditch, S.A.; Whitehead, W.S.

1988-06-01

Severe fracture-conductivity damage can result from proppant crushing and/or proppant flowback into the wellbore. Such damage is often concentrated near the wellbore and can directly affect postfracture performance. Most of the time severe fracture-conductivity damage can be minimized by choosing the correct type of proppant for a particular well. In many cases, however, this is not enough. To minimize excessive crushing or to prevent proppant flowback, it is also necessary to control carefully the flowback of the well after the treatment. Specific procedures can be followed to minimize severe fracture-conductivity damage. These procedures involve controlling the rates at which loadmore » fluids are recovered and maximizing backpressure against the formation. These procedures require much more time and effort than is normally spent on postfracture cleanup; however, the efforts could result in better performance.« less

A multi-objective decision-making approach to the journal submission problem.

PubMed

Wong, Tony E; Srikrishnan, Vivek; Hadka, David; Keller, Klaus

2017-01-01

When researchers complete a manuscript, they need to choose a journal to which they will submit the study. This decision requires to navigate trade-offs between multiple objectives. One objective is to share the new knowledge as widely as possible. Citation counts can serve as a proxy to quantify this objective. A second objective is to minimize the time commitment put into sharing the research, which may be estimated by the total time from initial submission to final decision. A third objective is to minimize the number of rejections and resubmissions. Thus, researchers often consider the trade-offs between the objectives of (i) maximizing citations, (ii) minimizing time-to-decision, and (iii) minimizing the number of resubmissions. To complicate matters further, this is a decision with multiple, potentially conflicting, decision-maker rationalities. Co-authors might have different preferences, for example about publishing fast versus maximizing citations. These diverging preferences can lead to conflicting trade-offs between objectives. Here, we apply a multi-objective decision analytical framework to identify the Pareto-front between these objectives and determine the set of journal submission pathways that balance these objectives for three stages of a researcher's career. We find multiple strategies that researchers might pursue, depending on how they value minimizing risk and effort relative to maximizing citations. The sequences that maximize expected citations within each strategy are generally similar, regardless of time horizon. We find that the "conditional impact factor"-impact factor times acceptance rate-is a suitable heuristic method for ranking journals, to strike a balance between minimizing effort objectives and maximizing citation count. Finally, we examine potential co-author tension resulting from differing rationalities by mapping out each researcher's preferred Pareto front and identifying compromise submission strategies. The explicit representation of trade-offs, especially when multiple decision-makers (co-authors) have different preferences, facilitates negotiations and can support the decision process.

A multi-objective decision-making approach to the journal submission problem

PubMed Central

Hadka, David; Keller, Klaus

2017-01-01

When researchers complete a manuscript, they need to choose a journal to which they will submit the study. This decision requires to navigate trade-offs between multiple objectives. One objective is to share the new knowledge as widely as possible. Citation counts can serve as a proxy to quantify this objective. A second objective is to minimize the time commitment put into sharing the research, which may be estimated by the total time from initial submission to final decision. A third objective is to minimize the number of rejections and resubmissions. Thus, researchers often consider the trade-offs between the objectives of (i) maximizing citations, (ii) minimizing time-to-decision, and (iii) minimizing the number of resubmissions. To complicate matters further, this is a decision with multiple, potentially conflicting, decision-maker rationalities. Co-authors might have different preferences, for example about publishing fast versus maximizing citations. These diverging preferences can lead to conflicting trade-offs between objectives. Here, we apply a multi-objective decision analytical framework to identify the Pareto-front between these objectives and determine the set of journal submission pathways that balance these objectives for three stages of a researcher’s career. We find multiple strategies that researchers might pursue, depending on how they value minimizing risk and effort relative to maximizing citations. The sequences that maximize expected citations within each strategy are generally similar, regardless of time horizon. We find that the “conditional impact factor”—impact factor times acceptance rate—is a suitable heuristic method for ranking journals, to strike a balance between minimizing effort objectives and maximizing citation count. Finally, we examine potential co-author tension resulting from differing rationalities by mapping out each researcher’s preferred Pareto front and identifying compromise submission strategies. The explicit representation of trade-offs, especially when multiple decision-makers (co-authors) have different preferences, facilitates negotiations and can support the decision process. PMID:28582430

Contributions of metabolic and temporal costs to human gait selection.

PubMed

Summerside, Erik M; Kram, Rodger; Ahmed, Alaa A

2018-06-01

Humans naturally select several parameters within a gait that correspond with minimizing metabolic cost. Much less is understood about the role of metabolic cost in selecting between gaits. Here, we asked participants to decide between walking or running out and back to different gait specific markers. The distance of the walking marker was adjusted after each decision to identify relative distances where individuals switched gait preferences. We found that neither minimizing solely metabolic energy nor minimizing solely movement time could predict how the group decided between gaits. Of our twenty participants, six behaved in a way that tended towards minimizing metabolic energy, while eight favoured strategies that tended more towards minimizing movement time. The remaining six participants could not be explained by minimizing a single cost. We provide evidence that humans consider not just a single movement cost, but instead a weighted combination of these conflicting costs with their relative contributions varying across participants. Individuals who placed a higher relative value on time ran faster than individuals who placed a higher relative value on metabolic energy. Sensitivity to temporal costs also explained variability in an individual's preferred velocity as a function of increasing running distance. Interestingly, these differences in velocity both within and across participants were absent in walking, possibly due to a steeper metabolic cost of transport curve. We conclude that metabolic cost plays an essential, but not exclusive role in gait decisions. © 2018 The Author(s).

Minimizing the Total Service Time of Discrete Dynamic Berth Allocation Problem by an Iterated Greedy Heuristic

PubMed Central

2014-01-01

Berth allocation is the forefront operation performed when ships arrive at a port and is a critical task in container port optimization. Minimizing the time ships spend at berths constitutes an important objective of berth allocation problems. This study focuses on the discrete dynamic berth allocation problem (discrete DBAP), which aims to minimize total service time, and proposes an iterated greedy (IG) algorithm to solve it. The proposed IG algorithm is tested on three benchmark problem sets. Experimental results show that the proposed IG algorithm can obtain optimal solutions for all test instances of the first and second problem sets and outperforms the best-known solutions for 35 out of 90 test instances of the third problem set. PMID:25295295

Accelerating Ground-Test Cycle Time: The Six-Minute Model Change and Other Visions for the 21st Century

NASA Technical Reports Server (NTRS)

Kegelman, Jerome T.

1998-01-01

The advantage of managing organizations to minimize product development cycle time has been well established. This paper provides an overview of the wind tunnel testing cycle time reduction activities at Langley Research Center (LaRC) and gives the status of several improvements in the wind tunnel productivity and cost reductions that have resulted from these activities. Processes have been examined and optimized. Metric data from monitoring processes provides guidance for investments in advanced technologies. The most promising technologies under implementation today include the use of formally designed experiments, a diverse array of quick disconnect technology and the judicious use of advanced electronic and information technologies.

Implementation and Comparison of Acoustic Travel-Time Measurement Procedures for the Helioseismic and Magnetic Imager Time-Distance Helioseismology Pipeline

NASA Technical Reports Server (NTRS)

Couvidat, S.; Zhao, J.; Birch, A. C.; Kosovichev, A. G.; Duvall, T. L., Jr.; Parchevsky, K.; Scherrer, P. H.

2009-01-01

The Helioseismic and Magnetic Imager (HMI) instrument on board the Solar Dynamics Observatory (SDO) satellite is designed to produce high-resolution Doppler velocity maps of oscillations at the solar surface with high temporal cadence. To take advantage of these high-quality oscillation data, a time-distance helioseismology pipeline has been implemented at the Joint Science Operations Center (JSOC) at Stanford University. The aim of this pipeline is to generate maps of acoustic travel times from oscillations on the solar surface, and to infer subsurface 3D flow velocities and sound-speed perturbations. The wave travel times are measured from cross covariances of the observed solar oscillation signals. For implementation into the pipeline we have investigated three different travel-time definitions developed in time-distance helioseismology: a Gabor wavelet fitting (Kosovichev and Duvall, 1997), a minimization relative to a reference cross-covariance function (Gizon and Birch, 2002), and a linearized version of the minimization method (Gizon and Birch, 2004). Using Doppler velocity data from the Michelson Doppler Imager (MDI) instrument on board SOHO, we tested and compared these definitions for the mean and difference travel-time perturbations measured from reciprocal signals. Although all three procedures return similar travel times in a quiet Sun region, the method of Gizon and Birch (2004) gives travel times that are significantly different from the others in a magnetic (active) region. Thus, for the pipeline implementation we chose the procedures of Kosovichev and Duvall (1997) and Gizon and Birch (2002). We investigated the relationships among these three travel-time definitions, their sensitivities to fitting parameters, and estimated the random errors they produce

A multi-objective optimization model for hub network design under uncertainty: An inexact rough-interval fuzzy approach

NASA Astrophysics Data System (ADS)

Niakan, F.; Vahdani, B.; Mohammadi, M.

2015-12-01

This article proposes a multi-objective mixed-integer model to optimize the location of hubs within a hub network design problem under uncertainty. The considered objectives include minimizing the maximum accumulated travel time, minimizing the total costs including transportation, fuel consumption and greenhouse emissions costs, and finally maximizing the minimum service reliability. In the proposed model, it is assumed that for connecting two nodes, there are several types of arc in which their capacity, transportation mode, travel time, and transportation and construction costs are different. Moreover, in this model, determining the capacity of the hubs is part of the decision-making procedure and balancing requirements are imposed on the network. To solve the model, a hybrid solution approach is utilized based on inexact programming, interval-valued fuzzy programming and rough interval programming. Furthermore, a hybrid multi-objective metaheuristic algorithm, namely multi-objective invasive weed optimization (MOIWO), is developed for the given problem. Finally, various computational experiments are carried out to assess the proposed model and solution approaches.

Estimation of anomaly location and size using electrical impedance tomography.

PubMed

Kwon, Ohin; Yoon, Jeong Rock; Seo, Jin Keun; Woo, Eung Je; Cho, Young Gu

2003-01-01

We developed a new algorithm that estimates locations and sizes of anomalies in electrically conducting medium based on electrical impedance tomography (EIT) technique. When only the boundary current and voltage measurements are available, it is not practically feasible to reconstruct accurate high-resolution cross-sectional conductivity or resistivity images of a subject. In this paper, we focus our attention on the estimation of locations and sizes of anomalies with different conductivity values compared with the background tissues. We showed the performance of the algorithm from experimental results using a 32-channel EIT system and saline phantom. With about 1.73% measurement error in boundary current-voltage data, we found that the minimal size (area) of the detectable anomaly is about 0.72% of the size (area) of the phantom. Potential applications include the monitoring of impedance related physiological events and bubble detection in two-phase flow. Since this new algorithm requires neither any forward solver nor time-consuming minimization process, it is fast enough for various real-time applications in medicine and nondestructive testing.

Athletes and blood clots: individualized, intermittent anticoagulation management.

PubMed

Berkowitz, J N; Moll, S

2017-06-01

Essentials Athletes on anticoagulants are typically prohibited from participation in contact sports. Short-acting anticoagulants allow for reconsideration of this precedent. An individualized pharmacokinetic/pharmacodynamics study can aid patient-specific management. Many challenges and unresolved issues exist regarding such tailored intermittent dosing. Athletes with venous thromboembolism (VTE) are typically prohibited from participating in contact sports during anticoagulation therapy, but such mandatory removal from competition can cause psychological and financial detriments for athletes and overlooks patient autonomy. The precedent of compulsory removal developed when options for anticoagulation therapy were more limited, but medical advances now allow for rethinking of the management of athletes with VTE. We propose a novel therapeutic approach to the treatment of athletes who participate in contact sports and require anticoagulation. A personalized pharmacokinetic/pharmacodynamics study of a direct oral anticoagulant can be performed for an athlete, which can inform the timing of medication dosing. Managed carefully, this can allow athletic participation when plasma drug concentration is minimal (minimizing bleeding risk) and prompt resumption of treatment after the risk of bleeding sufficiently normalizes (maximizing therapeutic time). © 2017 International Society on Thrombosis and Haemostasis.

Solar Concentration for Electricity and Cooking

NASA Astrophysics Data System (ADS)

Kim, Mike; Fourt, Connor; Schwartz, Pete; Lee, Michael; Frostholm, Taylor; Fernandes, Josh; Tower, Jared

2012-11-01

Over 8000 Schefflers exist worldwide, mostly in Africa and Asia. Having constructed the first Scheffler reflector in North America 2 years ago, the next goal was to make it less expensive. The original model took 4 students 2 months and about 1000. In order to lower the cost and construction time the design was minimized, less expensive materials were used, and the construction process was automated. The original complex frame took 1000 people-hours and it was minimized to a day. Instead of using aluminum for the reflective dish, we turned to using aluminized Mylar, which cut the cost by over 90%. A thermal storage unit was added to extend cooking time well into the evening. Finally, a concentrated solar module of High Efficiency Photo Voltaics (HEPV) is to be placed at the focus of the concentrator to generate electricity and water as a byproduct. The final cost is estimated to be about 200 (0.10 per thermal watt) including the HEPV, an 80% cost reduction. Such technology is practical in the U.S. as well as developing nations.

Developing AN Emergency Response Model for Offshore Oil Spill Disaster Management Using Spatial Decision Support System (sdss)

NASA Astrophysics Data System (ADS)

Balogun, Abdul-Lateef; Matori, Abdul-Nasir; Wong Toh Kiak, Kelvin

2018-04-01

Environmental resources face severe risks during offshore oil spill disasters and Geographic Information System (GIS) Environmental Sensitivity Index (ESI) maps are increasingly being used as response tools to minimize the huge impacts of these spills. However, ESI maps are generally unable to independently harmonize the diverse preferences of the multiple stakeholders' involved in the response process, causing rancour and delay in response time. This paper's Spatial Decision Support System (SDSS) utilizes the Analytic Hierarchy Process (AHP) model to perform tradeoffs in determining the most significant resources to be secured considering the limited resources and time available to perform the response operation. The AHP approach is used to aggregate the diverse preferences of the stakeholders and reach a consensus. These preferences, represented as priority weights, are incorporated in a GIS platform to generate Environmental sensitivity risk (ESR) maps. The ESR maps provide a common operational platform and consistent situational awareness for the multiple parties involved in the emergency response operation thereby minimizing discord among the response teams and saving the most valuable resources.

Development of a brain monitoring system for multimodality investigation in awake rats.

PubMed

Limnuson, Kanokwan; Narayan, Raj K; Chiluwal, Amrit; Bouton, Chad; Ping Wang; Chunyan Li

2016-08-01

Multimodal brain monitoring is an important approach to gain insight into brain function, modulation, and pathology. We have developed a unique micromachined neural probe capable of real-time continuous monitoring of multiple physiological, biochemical and electrophysiological variables. However, to date, it has only been used in anesthetized animals due to a lack of an appropriate interface for awake animals. We have developed a versatile headstage for recording the small neural signal and bridging the sensors to the remote sensing units for multimodal brain monitoring in awake rats. The developed system has been successfully validated in awake rats by simultaneously measuring four cerebral variables: electrocorticography, oxygen tension, temperature and cerebral blood flow. Reliable signal recordings were obtained with minimal artifacts from movement and environmental noise. For the first time, multiple variables of cerebral function and metabolism were simultaneously recorded from awake rats using a single neural probe. The system is envisioned for studying the effects of pharmacologic treatments, mapping the development of central nervous system diseases, and better understanding normal cerebral physiology.

Competitive two-agent scheduling problems to minimize the weighted combination of makespans in a two-machine open shop

NASA Astrophysics Data System (ADS)

Jiang, Fuhong; Zhang, Xingong; Bai, Danyu; Wu, Chin-Chia

2018-04-01

In this article, a competitive two-agent scheduling problem in a two-machine open shop is studied. The objective is to minimize the weighted sum of the makespans of two competitive agents. A complexity proof is presented for minimizing the weighted combination of the makespan of each agent if the weight α belonging to agent B is arbitrary. Furthermore, two pseudo-polynomial-time algorithms using the largest alternate processing time (LAPT) rule are presented. Finally, two approximation algorithms are presented if the weight is equal to one. Additionally, another approximation algorithm is presented if the weight is larger than one.

Minimally Invasive Surgery (MIS) Approaches to Thoracolumbar Trauma.

PubMed

Kaye, Ian David; Passias, Peter

2018-03-01

Minimally invasive surgical (MIS) techniques offer promising improvements in the management of thoracolumbar trauma. Recent advances in MIS techniques and instrumentation for degenerative conditions have heralded a growing interest in employing these techniques for thoracolumbar trauma. Specifically, surgeons have applied these techniques to help manage flexion- and extension-distraction injuries, neurologically intact burst fractures, and cases of damage control. Minimally invasive surgical techniques offer a means to decrease blood loss, shorten operative time, reduce infection risk, and shorten hospital stays. Herein, we review thoracolumbar minimally invasive surgery with an emphasis on thoracolumbar trauma classification, minimally invasive spinal stabilization, surgical indications, patient outcomes, technical considerations, and potential complications.

Lifelines for High School Climate Change Education

NASA Astrophysics Data System (ADS)

Gould, A. D.

2012-12-01

The Lifelines project aims to establish a network of practicing high school teachers actively using climate change curricula by creating professional learning communities (PLCs) of teachers who, through remote meetings and workshops, maintain ongoing communication and sharing of best practices among colleagues to strengthen knowledge and promote effective teaching strategies. The project explores techniques to achieve the most effective teleconferencing meetings and workshops. This promotes not only teaching about minimizing environmental impacts of human activity, but minimizes environmental impacts of professional development — practicing what we preach. To date, Lifelines PLCs have set up websites and e-mail lists for sharing information. Teleconferences and webinars have been held using services such as Skype, ReadyTalk, and Wiggio. Many of the meetings have been recorded and archived for the benefit of members who could not attend in real-time.

[Endoscopically assisted fronto-orbitary correction in trigonocephaly].

PubMed

Hinojosa, J; Esparza, J; García-Recuero, I; Romance, A

2007-01-01

The development of multidisciplinar Units for Craneofacial Surgery has led to a considerable decrease in morbidity even in the cases of more complex craniofacial syndromes. The use of minimally invasive techniques for the correction of some of these malformations allows the surgeon to minimize the incidence of complications by means of a decrease in the surgical time, blood salvage and shortening of postoperative hospitalization in comparison to conventional craniofacial techniques. Simple and milder craniosynostosis are best approached by these techniques and render the best results. Different osteotomies resembling standard fronto-orbital remodelling besides simple suturectomies and the use of postoperative cranial orthesis may improve the final aesthetic appearence. In endoscopic treatment of trigonocephaly the use of preauricular incisions achieves complete pterional resection, lower lateral orbital osteotomies and successful precoronal frontal osteotomies to obtain long lasting and satisfactory outcomes.

Dendritic cells for active immunotherapy: optimizing design and manufacture in order to develop commercially and clinically viable products.

PubMed

Nicolette, C A; Healey, D; Tcherepanova, I; Whelton, P; Monesmith, T; Coombs, L; Finke, L H; Whiteside, T; Miesowicz, F

2007-09-27

Dendritic cell (DC) active immunotherapy is potentially efficacious in a broad array of malignant disease settings. However, challenges remain in optimizing DC-based therapy for maximum clinical efficacy within manufacturing processes that permit quality control and scale-up of consistent products. In this review we discuss the critical issues that must be addressed in order to optimize DC-based product design and manufacture, and highlight the DC based platforms currently addressing these issues. Variables in DC-based product design include the type of antigenic payload used, DC maturation steps and activation processes, and functional assays. Issues to consider in development include: (a) minimizing the invasiveness of patient biological material collection; (b) minimizing handling and manipulations of tissue at the clinical site; (c) centralized product manufacturing and standardized processing and capacity for commercial-scale production; (d) rapid product release turnaround time; (e) the ability to manufacture sufficient product from limited starting material; and (f) standardized release criteria for DC phenotype and function. Improvements in the design and manufacture of DC products have resulted in a handful of promising leads currently in clinical development.

Flexible Job-Shop Scheduling with Dual-Resource Constraints to Minimize Tardiness Using Genetic Algorithm

NASA Astrophysics Data System (ADS)

Paksi, A. B. N.; Ma'ruf, A.

2016-02-01

In general, both machines and human resources are needed for processing a job on production floor. However, most classical scheduling problems have ignored the possible constraint caused by availability of workers and have considered only machines as a limited resource. In addition, along with production technology development, routing flexibility appears as a consequence of high product variety and medium demand for each product. Routing flexibility is caused by capability of machines that offers more than one machining process. This paper presents a method to address scheduling problem constrained by both machines and workers, considering routing flexibility. Scheduling in a Dual-Resource Constrained shop is categorized as NP-hard problem that needs long computational time. Meta-heuristic approach, based on Genetic Algorithm, is used due to its practical implementation in industry. Developed Genetic Algorithm uses indirect chromosome representative and procedure to transform chromosome into Gantt chart. Genetic operators, namely selection, elitism, crossover, and mutation are developed to search the best fitness value until steady state condition is achieved. A case study in a manufacturing SME is used to minimize tardiness as objective function. The algorithm has shown 25.6% reduction of tardiness, equal to 43.5 hours.

Compaction of Space Mission Wastes

NASA Technical Reports Server (NTRS)

Fisher, John; Pisharody, Suresh; Wignarajah, K.

2004-01-01

The current solid waste management system employed on the International Space Station (ISS) consists of compaction, storage, and disposal. Wastes such plastic food packaging and trash are compacted manually and wrapped in duct tape footballs by the astronauts. Much of the waste is simply loaded either into the empty Russian Progress vehicle for destruction on reentry or into Shuttle for return to Earth. This manual method is wasteful of crew time and does not transition well to far term missions. Different wastes onboard spacecraft vary considerably in their characteristics and in the appropriate method of management. In advanced life support systems for far term missions, recovery of resources such as water from the wastes becomes important. However waste such as plastic food packaging, which constitutes a large fraction of solid waste (roughly 21% on ISS, more on long duration missions), contains minimal recoverable resource. The appropriate management of plastic waste is waste stabilization and volume minimization rather than resource recovery. This paper describes work that has begun at Ames Research Center on development of a heat melt compactor that can be used on near term and future missions, that can minimize crew interaction, and that can handle wastes with a significant plastic composition. The heat melt compactor takes advantage of the low melting point of plastics to compact plastic materials using a combination of heat and pressure. The US Navy has demonstrated successful development of a similar unit for shipboard application. Ames is building upon the basic approach demonstrated by the Navy to develop an advanced heat melt type compactor for space mission type wastes.

Report of the Microbial Development Working Group

NASA Technical Reports Server (NTRS)

Nelson, G.

1985-01-01

In formulating ideas on the relationship of gravity to the development, growth, and reproduction of microorganisms, a rather liberal definition of microorganisms is used which includes bacteria, yeasts, protists, filamentous fungi, and single cells in culture. A principal advantage of microorganisms as experimental subjects is the rigor with which they can be defined and controlled. As single cells, each cell may be regarded as identical to the others in the population. This property applies to the morphology, physiology, and genetic parameters of the cells. The growth and development of the population is subject to precise manipulation as the nutritional requirements are known and minimal media formulations have been developed. Growth and differentiation can be manipulated in a variety of ways, such as alteration of the culture temperature and food supply, or by use of mutants. Finally, the short generation times of microorganisms provide the opportunity to conduct multigenerational studies within practical time limits and, in a similar vein, cellular responses to various stimuli or stresses are conveniently monitored because of the rapid response times of single cells.

Optimal regulation in systems with stochastic time sampling

NASA Technical Reports Server (NTRS)

Montgomery, R. C.; Lee, P. S.

1980-01-01

An optimal control theory that accounts for stochastic variable time sampling in a distributed microprocessor based flight control system is presented. The theory is developed by using a linear process model for the airplane dynamics and the information distribution process is modeled as a variable time increment process where, at the time that information is supplied to the control effectors, the control effectors know the time of the next information update only in a stochastic sense. An optimal control problem is formulated and solved for the control law that minimizes the expected value of a quadratic cost function. The optimal cost obtained with a variable time increment Markov information update process where the control effectors know only the past information update intervals and the Markov transition mechanism is almost identical to that obtained with a known and uniform information update interval.

The evolution and future of minimalism in neurological surgery.

PubMed

Liu, Charles Y; Wang, Michael Y; Apuzzo, Michael L J

2004-11-01

The evolution of the field of neurological surgery has been marked by a progressive minimalism. This has been evident in the development of an entire arsenal of modern neurosurgical enterprises, including microneurosurgery, neuroendoscopy, stereotactic neurosurgery, endovascular techniques, radiosurgical systems, intraoperative and navigational devices, and in the last decade, cellular and molecular adjuvants. In addition to reviewing the major developments and paradigm shifts in the cyclic reinvention of the field as it currently stands, this paper attempts to identify forces and developments that are likely to fuel the irresistible escalation of minimalism into the future. These forces include discoveries in computational science, imaging, molecular science, biomedical engineering, and information processing as they relate to the theme of minimalism. These areas are explained in the light of future possibilities offered by the emerging field of nanotechnology with molecular engineering.

Microgravity ignition experiment

NASA Technical Reports Server (NTRS)

Motevalli, Vahid; Elliott, William; Garrant, Keith

1992-01-01

The purpose of this project is to develop a flight ready apparatus of the microgravity ignition experiment for the GASCan 2 program. This involved redesigning, testing, and making final modifications to the existing apparatus. The microgravity ignition experiment is intended to test the effect of microgravity on the time to ignition of a sample of alpha-cellulose paper. An infrared heat lamp is used to heat the paper sample within a sealed canister. The interior of the canister was redesigned to increase stability and minimize conductive heat transfer to the sample. This design was fabricated and tested and a heat transfer model of the paper sample was developed.

Workshop on imaging science development for cancer prevention and preemption.

PubMed

Kelloff, Gary J; Sullivan, Daniel C; Baker, Houston; Clarke, Lawrence P; Nordstrom, Robert; Tatum, James L; Dorfman, Gary S; Jacobs, Paula; Berg, Christine D; Pomper, Martin G; Birrer, Michael J; Tempero, Margaret; Higley, Howard R; Petty, Brenda Gumbs; Sigman, Caroline C; Maley, Carlo; Sharma, Prateek; Wax, Adam; Ginsberg, Gregory G; Dannenberg, Andrew J; Hawk, Ernest T; Messing, Edward M; Grossman, H Barton; Harisinghani, Mukesh; Bigio, Irving J; Griebel, Donna; Henson, Donald E; Fabian, Carol J; Ferrara, Katherine; Fantini, Sergio; Schnall, Mitchell D; Zujewski, Jo Anne; Hayes, Wendy; Klein, Eric A; DeMarzo, Angelo; Ocak, Iclal; Ketterling, Jeffrey A; Tempany, Clare; Shtern, Faina; Parnes, Howard L; Gomez, Jorge; Srivastava, Sudhir; Szabo, Eva; Lam, Stephen; Seibel, Eric J; Massion, Pierre; McLennan, Geoffrey; Cleary, Kevin; Suh, Robert; Burt, Randall W; Pfeiffer, Ruth M; Hoffman, John M; Roy, Hemant K; Wang, Thomas; Limburg, Paul J; El-Deiry, Wafik S; Papadimitrakopoulou, Vali; Hittelman, Walter N; MacAulay, Calum; Veltri, Robert W; Solomon, Diane; Jeronimo, Jose; Richards-Kortum, Rebecca; Johnson, Karen A; Viner, Jaye L; Stratton, Steven P; Rajadhyaksha, Milind; Dhawan, Atam

2007-01-01

The concept of intraepithelial neoplasm (IEN) as a near-obligate precursor of cancers has generated opportunities to examine drug or device intervention strategies that may reverse or retard the sometimes lengthy process of carcinogenesis. Chemopreventive agents with high therapeutic indices, well-monitored for efficacy and safety, are greatly needed, as is development of less invasive or minimally disruptive visualization and assessment methods to safely screen nominally healthy but at-risk patients, often for extended periods of time and at repeated intervals. Imaging devices, alone or in combination with anticancer drugs, may also provide novel interventions to treat or prevent precancer.

An Optimization of Manufacturing Systems using a Feedback Control Scheduling Model

NASA Astrophysics Data System (ADS)

Ikome, John M.; Kanakana, Grace M.

2018-03-01

In complex production system that involves multiple process, unplanned disruption often turn to make the entire production system vulnerable to a number of problems which leads to customer’s dissatisfaction. However, this problem has been an ongoing problem that requires a research and methods to streamline the entire process or develop a model that will address it, in contrast to this, we have developed a feedback scheduling model that can minimize some of this problem and after a number of experiment, it shows that some of this problems can be eliminated if the correct remedial actions are implemented on time.

Thermal energy storage for industrial waste heat recovery

NASA Technical Reports Server (NTRS)

Hoffman, H. W.; Kedl, R. J.; Duscha, R. A.

1978-01-01

The potential is examined for waste heat recovery and reuse through thermal energy storage in five specific industrial categories: (1) primary aluminum, (2) cement, (3) food processing, (4) paper and pulp, and (5) iron and steel. Preliminary results from Phase 1 feasibility studies suggest energy savings through fossil fuel displacement approaching 0.1 quad/yr in the 1985 period. Early implementation of recovery technologies with minimal development appears likely in the food processing and paper and pulp industries; development of the other three categories, though equally desirable, will probably require a greater investment in time and dollars.

Development and validation of a minimal growth medium for recycling Chlorella vulgaris culture.

PubMed

Hadj-Romdhane, F; Jaouen, P; Pruvost, J; Grizeau, D; Van Vooren, G; Bourseau, P

2012-11-01

When microalgae culture medium is recycled, ions (e.g. Na(+), K(+), Ca(2+)) that were not assimilated by the microalgae accumulate in the medium. Therefore, a growth medium (HAMGM) was developed that included ions that were more easily assimilated by Chlorella vulgaris, such as ammonium one (NH(4)(+)). Recycling performance was studied by carrying out 8-week continuous cultivation of C. vulgaris with recycled HAMGM medium. No loss of biomass productivity was observed compared to culture in a conventional medium, and accumulation of ions over time was negligible. Copyright © 2012 Elsevier Ltd. All rights reserved.

GPS: Public Utility or Software Platform

DTIC Science & Technology

2016-09-01

major occurrences that could interrupt GPS’s operation for an extended period of time . Despite these safeguards, the U.S. government has...in the event of a GPS interruption .178 2. GPS Infrastructure is designed to Prevent and Minimize Disruption Like a public utility, GPS is designed ...production and distribution while at the same time minimizing the likelihood of signal interruptions . Each of GPS’s operational satellites are

DOE Office of Scientific and Technical Information (OSTI.GOV)

Syracuse, Ellen Marie; Maceira, Monica; Phillips, William Scott

These are slides which show many graphs and datasets for the above-mentioned topic and then concludes with the following: Joint inversion of multiple geophysical datasets improves recovery of velocity structures, particularly in Vs and in shallow parts of the model, in comparison to travel-time only models. Resulting fits to travel time data are minimally degraded by joint inversions. Correspondingly, fits to independent estimates of ground-truth locations are minimally affected by joint inversions.

Gingival recession in smokers and non-smokers with minimal periodontal disease.

PubMed

Müller, Hans-Peter; Stadermann, Sabine; Heinecke, Achim

2002-02-01

Smoking is a major risk factor for destructive periodontal disease. There is limited information with regard to effects of smoking in subjects with minimal periodontal destruction. The aim of the present investigation was to assess the development of gingival recession in young adult smokers and non-smokers. 61 systemically healthy young adults, 19 to 30 years of age completed the final examination. 30 volunteers smoked at least 20 cigarettes per day, whereas 31 subjects were non-smokers. Clinical periodontal conditions were assessed 4x within a time period of 6 months. Site-specific analyses considering the correlated structure of data were performed. At the outset, 50% of subjects presented with gingival recession at 1 or more sites. There was no significant difference in the prevalence of gingival recession between non-smokers and smokers. Severe recession in excess of 2 mm affected about 23% non-smokers but only 7% smokers. Some further gingival recession developed during the 6-month observation period. In a multivariate logistic regression analysis, the risk for recession development appeared not to be influenced by smoking status after adjusting for periodontal probing depth, recession at baseline, tooth brushing frequency, gender, jaw, tooth type and site. Present data did not support the hypothesis that smokers are at an increased risk for the development of gingival recession.

Asteroid Crew Segment Mission Lean Development

NASA Technical Reports Server (NTRS)

Gard, Joseph; McDonald, Mark

2014-01-01

Asteroid Retrieval Crewed Mission (ARCM) requires a minimum set of Key Capabilities compared in the context of the baseline EM-1/2 Orion and SLS capabilities. These include: Life Support & Human Systems Capabilities; Mission Kit Capabilities; Minimizing the impact to the Orion and SLS development schedules and funding. Leveraging existing technology development efforts to develop the kits adds functionality to Orion while minimizing cost and mass impact.

Joint Center Estimation Using Single-Frame Optimization: Part 1: Numerical Simulation.

PubMed

Frick, Eric; Rahmatalla, Salam

2018-04-04

The biomechanical models used to refine and stabilize motion capture processes are almost invariably driven by joint center estimates, and any errors in joint center calculation carry over and can be compounded when calculating joint kinematics. Unfortunately, accurate determination of joint centers is a complex task, primarily due to measurements being contaminated by soft-tissue artifact (STA). This paper proposes a novel approach to joint center estimation implemented via sequential application of single-frame optimization (SFO). First, the method minimizes the variance of individual time frames’ joint center estimations via the developed variance minimization method to obtain accurate overall initial conditions. These initial conditions are used to stabilize an optimization-based linearization of human motion that determines a time-varying joint center estimation. In this manner, the complex and nonlinear behavior of human motion contaminated by STA can be captured as a continuous series of unique rigid-body realizations without requiring a complex analytical model to describe the behavior of STA. This article intends to offer proof of concept, and the presented method must be further developed before it can be reasonably applied to human motion. Numerical simulations were introduced to verify and substantiate the efficacy of the proposed methodology. When directly compared with a state-of-the-art inertial method, SFO reduced the error due to soft-tissue artifact in all cases by more than 45%. Instead of producing a single vector value to describe the joint center location during a motion capture trial as existing methods often do, the proposed method produced time-varying solutions that were highly correlated ( r > 0.82) with the true, time-varying joint center solution.

A model for methane production in sewers.

PubMed

Chaosakul, Thitirat; Koottatep, Thammarat; Polprasert, Chongrak

2014-09-19

Most sewers in developing countries are combined sewers which receive stormwater and effluent from septic tanks or cesspools of households and buildings. Although the wastewater strength in these sewers is usually lower than those in developed countries, due to improper construction and maintenance, the hydraulic retention time (HRT) could be relatively long and resulting considerable greenhouse gas (GHG) production. This study proposed an empirical model to predict the quantity of methane production in gravity-flow sewers based on relevant parameters such as surface area to volume ratio (A/V) of sewer, hydraulic retention time (HRT) and wastewater temperature. The model was developed from field survey data of gravity-flow sewers located in a peri-urban area, central Thailand and validated with field data of a sewer system of the Gold Coast area, Queensland, Australia. Application of this model to improve construction and maintenance of gravity-flow sewers to minimize GHG production and reduce global warming is presented.

Real time control for NASA robotic gripper

NASA Technical Reports Server (NTRS)

Salter, Carole A.; Baras, John S.

1990-01-01

The ability to easily manipulate objects in a zero gravity environment will pay a key role in future space activities. Emphasis will be placed on robotic manipulation. This will serve to increase astronaut safety and utility in addition to several other benefits. The aim is to develop control laws for the zero gravity robotic end effectors. A hybrid force/position controller will be used. Sensory data available to the controller are obtained from an array of strain gauges and a linear potentiometer. Applying well known optimal control theoretical principles, the control which minimizes the transition time between positions is obtained. A robust force control scheme is developed which allows the desired holding force to be achieved smoothly without oscillation. In addition, an algorithm is found to determine contact force and contact location.

Developing a space network interface simulator: The NTS approach

NASA Technical Reports Server (NTRS)

Hendrzak, Gary E.

1993-01-01

This paper describes the approach used to redevelop the Network Control Center (NCC) Test System (NTS), a hardware and software facility designed to make testing of the NCC Data System (NCCDS) software efficient, effective, and as rigorous as possible prior to operational use. The NTS transmits and receives network message traffic in real-time. Data transfer rates and message content are strictly controlled and are identical to that of the operational systems. NTS minimizes the need for costly and time-consuming testing with the actual external entities (e.g., the Hubble Space Telescope (HST) Payload Operations Control Center (POCC) and the White Sands Ground Terminal). Discussed are activities associated with the development of the NTS, lessons learned throughout the project's lifecycle, and resulting productivity and quality increases.

Precision Departure Release Capability (PDRC) Overview and Results: NASA to FAA Research Transition

NASA Technical Reports Server (NTRS)

Engelland, Shawn; Davis, Tom.

2013-01-01

NASA researchers developed the Precision Departure Release Capability (PDRC) concept to improve the tactical departure scheduling process. The PDRC system is comprised of: 1) a surface automation system that computes ready time predictions and departure runway assignments, 2) an en route scheduling automation tool that uses this information to estimate ascent trajectories to the merge point and computes release times and, 3) an interface that provides two-way communication between the two systems. To minimize technology transfer issues and facilitate its adoption by TMCs and Frontline Managers (FLM), NASA developed the PDRC prototype using the Surface Decision Support System (SDSS) for the Tower surface automation tool, a research version of the FAA TMA (RTMA) for en route automation tool and a digital interface between the two DSTs to facilitate coordination.

Measuring Changes in Social Communication Behaviors: Preliminary Development of the Brief Observation of Social Communication Change (BOSCC).

PubMed

Grzadzinski, Rebecca; Carr, Themba; Colombi, Costanza; McGuire, Kelly; Dufek, Sarah; Pickles, Andrew; Lord, Catherine

2016-07-01

Psychometric properties and initial validity of the Brief Observation of Social Communication Change (BOSCC), a measure of treatment-response for social-communication behaviors, are described. The BOSCC coding scheme is applied to 177 video observations of 56 young children with ASD and minimal language abilities. The BOSCC has high to excellent inter-rater and test-retest reliability and shows convergent validity with measures of language and communication skills. The BOSCC Core total demonstrates statistically significant amounts of change over time compared to a no change alternative while the ADOS CSS over the same period of time did not. This work is a first step in the development of a novel outcome measure for social-communication behaviors with applications to clinical trials and longitudinal studies.

An Injury Severity-, Time Sensitivity-, and Predictability-Based Advanced Automatic Crash Notification Algorithm Improves Motor Vehicle Crash Occupant Triage.

PubMed

Stitzel, Joel D; Weaver, Ashley A; Talton, Jennifer W; Barnard, Ryan T; Schoell, Samantha L; Doud, Andrea N; Martin, R Shayn; Meredith, J Wayne

2016-06-01

Advanced Automatic Crash Notification algorithms use vehicle telemetry measurements to predict risk of serious motor vehicle crash injury. The objective of the study was to develop an Advanced Automatic Crash Notification algorithm to reduce response time, increase triage efficiency, and improve patient outcomes by minimizing undertriage (<5%) and overtriage (<50%), as recommended by the American College of Surgeons. A list of injuries associated with a patient's need for Level I/II trauma center treatment known as the Target Injury List was determined using an approach based on 3 facets of injury: severity, time sensitivity, and predictability. Multivariable logistic regression was used to predict an occupant's risk of sustaining an injury on the Target Injury List based on crash severity and restraint factors for occupants in the National Automotive Sampling System - Crashworthiness Data System 2000-2011. The Advanced Automatic Crash Notification algorithm was optimized and evaluated to minimize triage rates, per American College of Surgeons recommendations. The following rates were achieved: <50% overtriage and <5% undertriage in side impacts and 6% to 16% undertriage in other crash modes. Nationwide implementation of our algorithm is estimated to improve triage decisions for 44% of undertriaged and 38% of overtriaged occupants. Annually, this translates to more appropriate care for >2,700 seriously injured occupants and reduces unnecessary use of trauma center resources for >162,000 minimally injured occupants. The algorithm could be incorporated into vehicles to inform emergency personnel of recommended motor vehicle crash triage decisions. Lower under- and overtriage was achieved, and nationwide implementation of the algorithm would yield improved triage decision making for an estimated 165,000 occupants annually. Copyright © 2016. Published by Elsevier Inc.

Orbit design and optimization based on global telecommunication performance metrics

NASA Technical Reports Server (NTRS)

Lee, Seungwon; Lee, Charles H.; Kerridge, Stuart; Cheung, Kar-Ming; Edwards, Charles D.

2006-01-01

The orbit selection of telecommunications orbiters is one of the critical design processes and should be guided by global telecom performance metrics and mission-specific constraints. In order to aid the orbit selection, we have coupled the Telecom Orbit Analysis and Simulation Tool (TOAST) with genetic optimization algorithms. As a demonstration, we have applied the developed tool to select an optimal orbit for general Mars telecommunications orbiters with the constraint of being a frozen orbit. While a typical optimization goal is to minimize tele-communications down time, several relevant performance metrics are examined: 1) area-weighted average gap time, 2) global maximum of local maximum gap time, 3) global maximum of local minimum gap time. Optimal solutions are found with each of the metrics. Common and different features among the optimal solutions as well as the advantage and disadvantage of each metric are presented. The optimal solutions are compared with several candidate orbits that were considered during the development of Mars Telecommunications Orbiter.

Search for Minimal and Semi-Minimal Rule Sets in Incremental Learning of Context-Free and Definite Clause Grammars

NASA Astrophysics Data System (ADS)

Imada, Keita; Nakamura, Katsuhiko

This paper describes recent improvements to Synapse system for incremental learning of general context-free grammars (CFGs) and definite clause grammars (DCGs) from positive and negative sample strings. An important feature of our approach is incremental learning, which is realized by a rule generation mechanism called “bridging” based on bottom-up parsing for positive samples and the search for rule sets. The sizes of rule sets and the computation time depend on the search strategies. In addition to the global search for synthesizing minimal rule sets and serial search, another method for synthesizing semi-optimum rule sets, we incorporate beam search to the system for synthesizing semi-minimal rule sets. The paper shows several experimental results on learning CFGs and DCGs, and we analyze the sizes of rule sets and the computation time.

A Smart-Home System to Unobtrusively and Continuously Assess Loneliness in Older Adults

PubMed Central

Dodge, Hiroko H.; Riley, Thomas; Jacobs, Peter G.; Thielke, Stephen; Kaye, Jeffrey

2016-01-01

Loneliness is a common condition in older adults and is associated with increased morbidity and mortality, decreased sleep quality, and increased risk of cognitive decline. Assessing loneliness in older adults is challenging due to the negative desirability biases associated with being lonely. Thus, it is necessary to develop more objective techniques to assess loneliness in older adults. In this paper, we describe a system to measure loneliness by assessing in-home behavior using wireless motion and contact sensors, phone monitors, and computer software as well as algorithms developed to assess key behaviors of interest. We then present results showing the accuracy of the system in detecting loneliness in a longitudinal study of 16 older adults who agreed to have the sensor platform installed in their own homes for up to 8 months. We show that loneliness is significantly associated with both time out-of-home (\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$ {\\beta } = -0.88$ \\end{document} and \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$p<0.01$ \\end{document}) and number of computer sessions (\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$ {\\beta } = 0.78$ \\end{document} and \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$p<0.05$ \\end{document}). \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$R^{2}$ \\end{document} for the model was 0.35. We also show the model’s ability to predict out-of-sample loneliness, demonstrating that the correlation between true loneliness and predicted out-of-sample loneliness is 0.48. When compared with the University of California at Los Angeles loneliness score, the normalized mean absolute error of the predicted loneliness scores was 0.81 and the normalized root mean squared error was 0.91. These results represent first steps toward an unobtrusive, objective method for the prediction of loneliness among older adults, and mark the first time multiple objective behavioral measures that have been related to this key health outcome. PMID:27574577

A wavelet based approach to measure and manage contagion at different time scales

NASA Astrophysics Data System (ADS)

Berger, Theo

2015-10-01

We decompose financial return series of US stocks into different time scales with respect to different market regimes. First, we examine dependence structure of decomposed financial return series and analyze the impact of the current financial crisis on contagion and changing interdependencies as well as upper and lower tail dependence for different time scales. Second, we demonstrate to which extent the information of different time scales can be used in the context of portfolio management. As a result, minimizing the variance of short-run noise outperforms a portfolio that minimizes the variance of the return series.

Multi-Objective Flight Control for Drag Minimization and Load Alleviation of High-Aspect Ratio Flexible Wing Aircraft

NASA Technical Reports Server (NTRS)

Nguyen, Nhan; Ting, Eric; Chaparro, Daniel; Drew, Michael; Swei, Sean

2017-01-01

As aircraft wings become much more flexible due to the use of light-weight composites material, adverse aerodynamics at off-design performance can result from changes in wing shapes due to aeroelastic deflections. Increased drag, hence increased fuel burn, is a potential consequence. Without means for aeroelastic compensation, the benefit of weight reduction from the use of light-weight material could be offset by less optimal aerodynamic performance at off-design flight conditions. Performance Adaptive Aeroelastic Wing (PAAW) technology can potentially address these technical challenges for future flexible wing transports. PAAW technology leverages multi-disciplinary solutions to maximize the aerodynamic performance payoff of future adaptive wing design, while addressing simultaneously operational constraints that can prevent the optimal aerodynamic performance from being realized. These operational constraints include reduced flutter margins, increased airframe responses to gust and maneuver loads, pilot handling qualities, and ride qualities. All of these constraints while seeking the optimal aerodynamic performance present themselves as a multi-objective flight control problem. The paper presents a multi-objective flight control approach based on a drag-cognizant optimal control method. A concept of virtual control, which was previously introduced, is implemented to address the pair-wise flap motion constraints imposed by the elastomer material. This method is shown to be able to satisfy the constraints. Real-time drag minimization control is considered to be an important consideration for PAAW technology. Drag minimization control has many technical challenges such as sensing and control. An initial outline of a real-time drag minimization control has already been developed and will be further investigated in the future. A simulation study of a multi-objective flight control for a flight path angle command with aeroelastic mode suppression and drag minimization demonstrates the effectiveness of the proposed solution. In-flight structural loads are also an important consideration. As wing flexibility increases, maneuver load and gust load responses can be significant and therefore can pose safety and flight control concerns. In this paper, we will extend the multi-objective flight control framework to include load alleviation control. The study will focus initially on maneuver load minimization control, and then subsequently will address gust load alleviation control in future work.

Near DC force measurement using PVDF sensors

NASA Astrophysics Data System (ADS)

Ramanathan, Arun Kumar; Headings, Leon M.; Dapino, Marcelo J.

2018-03-01

There is a need for high-performance force sensors capable of operating at frequencies near DC while producing a minimal mass penalty. Example application areas include steering wheel sensors, powertrain torque sensors, robotic arms, and minimally invasive surgery. The beta crystallographic phase polyvinylidene fluoride (PVDF) films are suitable for this purpose owing to their large piezoelectric constant. Unlike conventional capacitive sensors, beta crystallographic phase PVDF films exhibit a broad linear range and can potentially be designed to operate without complex electronics or signal processing. A fundamental challenge that prevents the implementation of PVDF in certain high-performance applications is their inability to measure static signals, which results from their first-order electrical impedance. Charge readout algorithms have been implemented which address this issue only partially, as they often require integration of the output signal to obtain the applied force profile, resulting in signal drift and signal processing complexities. In this paper, we propose a straightforward real time drift compensation strategy that is applicable to high output impedance PVDF films. This strategy makes it possible to utilize long sample times with a minimal loss of accuracy; our measurements show that the static output remains within 5% of the original value during half-hour measurements. The sensitivity and full-scale range are shown to be determined by the feedback capacitance of the charge amplifier. A linear model of the PVDF sensor system is developed and validated against experimental measurements, along with benchmark tests against a commercial load cell.

Advanced illumination control algorithm for medical endoscopy applications

NASA Astrophysics Data System (ADS)

Sousa, Ricardo M.; Wäny, Martin; Santos, Pedro; Morgado-Dias, F.

2015-05-01

CMOS image sensor manufacturer, AWAIBA, is providing the world's smallest digital camera modules to the world market for minimally invasive surgery and one time use endoscopic equipment. Based on the world's smallest digital camera head and the evaluation board provided to it, the aim of this paper is to demonstrate an advanced fast response dynamic control algorithm of the illumination LED source coupled to the camera head, over the LED drivers embedded on the evaluation board. Cost efficient and small size endoscopic camera modules nowadays embed minimal size image sensors capable of not only adjusting gain and exposure time but also LED illumination with adjustable illumination power. The LED illumination power has to be dynamically adjusted while navigating the endoscope over changing illumination conditions of several orders of magnitude within fractions of the second to guarantee a smooth viewing experience. The algorithm is centered on the pixel analysis of selected ROIs enabling it to dynamically adjust the illumination intensity based on the measured pixel saturation level. The control core was developed in VHDL and tested in a laboratory environment over changing light conditions. The obtained results show that it is capable of achieving correction speeds under 1 s while maintaining a static error below 3% relative to the total number of pixels on the image. The result of this work will allow the integration of millimeter sized high brightness LED sources on minimal form factor cameras enabling its use in endoscopic surgical robotic or micro invasive surgery.

Minimally invasive image-guided keyhole aspiration of cerebral abscesses.

PubMed

Meng, Xiang-Hui; Feng, Shi-Yu; Chen, Xiao-Lei; Li, Chong; Zhang, Jiashu; Zhou, Tao; Jiang, Jinli; Wang, Fuyu; Ma, Xiaodong; Bu, Bo; Yu, Xin-Guang

2015-01-01

Despite the low incidence of brain abscesses in Western nations (1-2%), the incidence in developing countries is as high as 8%. We evaluate a minimally invasive image-guided keyhole aspiration of cerebral abscesses and compare it with a series of cases treated with surgical excision. 23 patients (20 male and 3 female, aged 7-67 years) underwent image-guided burr hole aspiration of single or multiple cerebral abscesses. Patient characteristics, perioperative, and postoperative data were analyzed and compared with a second group of 22 patients (14 male and 8 female, aged 12-72) treated for cerebral abscesses with open surgical excision. In all cases, the surgical procedure was performed successfully without complication. 8 of the 23 aspiration cases were performed with the aid of iMRI. A comparison of patient demographics, duration of hospital stay, duration of antibiotic therapy, postoperative neurological recovery time, intraoperative blood loss, operative duration, length of incision, postoperative fever, repeat surgery, and mortality was performed between the aspiration and excision groups. Intraoperative blood loss, operative duration, length of incision, and postoperative fever were all significantly reduced in the aspiration group. Though, duration of hospital stay and antibiotic therapy and postoperative neurological recovery time were all increased in the aspiration group, and statistical significance was observed in all except the duration of hospital stay. This technique is a feasible and comparable minimally invasive alternative to open surgical excision and may provide reduced intraoperative blood loss, shortened operative duration, improved cosmetic outcomes, and a lessened incidence of postoperative fever.

Efficient Deterministic Finite Automata Minimization Based on Backward Depth Information.

PubMed

Liu, Desheng; Huang, Zhiping; Zhang, Yimeng; Guo, Xiaojun; Su, Shaojing

2016-01-01

Obtaining a minimal automaton is a fundamental issue in the theory and practical implementation of deterministic finite automatons (DFAs). A minimization algorithm is presented in this paper that consists of two main phases. In the first phase, the backward depth information is built, and the state set of the DFA is partitioned into many blocks. In the second phase, the state set is refined using a hash table. The minimization algorithm has a lower time complexity O(n) than a naive comparison of transitions O(n2). Few states need to be refined by the hash table, because most states have been partitioned by the backward depth information in the coarse partition. This method achieves greater generality than previous methods because building the backward depth information is independent of the topological complexity of the DFA. The proposed algorithm can be applied not only to the minimization of acyclic automata or simple cyclic automata, but also to automata with high topological complexity. Overall, the proposal has three advantages: lower time complexity, greater generality, and scalability. A comparison to Hopcroft's algorithm demonstrates experimentally that the algorithm runs faster than traditional algorithms.

Ares-I Bending Filter Design using a Constrained Optimization Approach

NASA Technical Reports Server (NTRS)

Hall, Charles; Jang, Jiann-Woei; Hall, Robert; Bedrossian, Nazareth

2008-01-01

The Ares-I launch vehicle represents a challenging flex-body structural environment for control system design. Software filtering of the inertial sensor output is required to ensure adequate stable response to guidance commands while minimizing trajectory deviations. This paper presents a design methodology employing numerical optimization to develop the Ares-I bending filters. The design objectives include attitude tracking accuracy and robust stability with respect to rigid body dynamics, propellant slosh, and flex. Under the assumption that the Ares-I time-varying dynamics and control system can be frozen over a short period of time, the bending filters are designed to stabilize all the selected frozen-time launch control systems in the presence of parameter uncertainty. To ensure adequate response to guidance command, step response specifications are introduced as constraints in the optimization problem. Imposing these constrains minimizes performance degradation caused by the addition of the bending filters. The first stage bending filter design achieves stability by adding lag to the first structural frequency to phase stabilize the first flex mode while gain stabilizing the higher modes. The upper stage bending filter design gain stabilizes all the flex bending modes. The bending filter designs provided here have been demonstrated to provide stable first and second stage control systems in both Draper Ares Stability Analysis Tool (ASAT) and the MSFC MAVERIC 6DOF nonlinear time domain simulation.

Ares I Flight Control System Design

NASA Technical Reports Server (NTRS)

Jang, Jiann-Woei; Alaniz, Abran; Hall, Robert; Bedrossian, Nazareth; Hall, Charles; Ryan, Stephen; Jackson, Mark

2010-01-01

The Ares I launch vehicle represents a challenging flex-body structural environment for flight control system design. This paper presents a design methodology for employing numerical optimization to develop the Ares I flight control system. The design objectives include attitude tracking accuracy and robust stability with respect to rigid body dynamics, propellant slosh, and flex. Under the assumption that the Ares I time-varying dynamics and control system can be frozen over a short period of time, the flight controllers are designed to stabilize all selected frozen-time launch control systems in the presence of parametric uncertainty. Flex filters in the flight control system are designed to minimize the flex components in the error signals before they are sent to the attitude controller. To ensure adequate response to guidance command, step response specifications are introduced as constraints in the optimization problem. Imposing these constraints minimizes performance degradation caused by the addition of the flex filters. The first stage bending filter design achieves stability by adding lag to the first structural frequency to phase stabilize the first flex mode while gain stabilizing the higher modes. The upper stage bending filter design gain stabilizes all the flex bending modes. The flight control system designs provided here have been demonstrated to provide stable first and second stage control systems in both Draper Ares Stability Analysis Tool (ASAT) and the MSFC 6DOF nonlinear time domain simulation.

Analysis of the effects of Eye-Tracker performance on the pulse positioning errors during refractive surgery☆

PubMed Central

Arba-Mosquera, Samuel; Aslanides, Ioannis M.

2012-01-01

Purpose To analyze the effects of Eye-Tracker performance on the pulse positioning errors during refractive surgery. Methods A comprehensive model, which directly considers eye movements, including saccades, vestibular, optokinetic, vergence, and miniature, as well as, eye-tracker acquisition rate, eye-tracker latency time, scanner positioning time, laser firing rate, and laser trigger delay have been developed. Results Eye-tracker acquisition rates below 100 Hz correspond to pulse positioning errors above 1.5 mm. Eye-tracker latency times to about 15 ms correspond to pulse positioning errors of up to 3.5 mm. Scanner positioning times to about 9 ms correspond to pulse positioning errors of up to 2 mm. Laser firing rates faster than eye-tracker acquisition rates basically duplicate pulse-positioning errors. Laser trigger delays to about 300 μs have minor to no impact on pulse-positioning errors. Conclusions The proposed model can be used for comparison of laser systems used for ablation processes. Due to the pseudo-random nature of eye movements, positioning errors of single pulses are much larger than observed decentrations in the clinical settings. There is no single parameter that ‘alone’ minimizes the positioning error. It is the optimal combination of the several parameters that minimizes the error. The results of this analysis are important to understand the limitations of correcting very irregular ablation patterns.

A Double-difference Earthquake location algorithm: Method and application to the Northern Hayward Fault, California

USGS Publications Warehouse

Waldhauser, F.; Ellsworth, W.L.

2000-01-01

We have developed an efficient method to determine high-resolution hypocenter locations over large distances. The location method incorporates ordinary absolute travel-time measurements and/or cross-correlation P-and S-wave differential travel-time measurements. Residuals between observed and theoretical travel-time differences (or double-differences) are minimized for pairs of earthquakes at each station while linking together all observed event-station pairs. A least-squares solution is found by iteratively adjusting the vector difference between hypocentral pairs. The double-difference algorithm minimizes errors due to unmodeled velocity structure without the use of station corrections. Because catalog and cross-correlation data are combined into one system of equations, interevent distances within multiplets are determined to the accuracy of the cross-correlation data, while the relative locations between multiplets and uncorrelated events are simultaneously determined to the accuracy of the absolute travel-time data. Statistical resampling methods are used to estimate data accuracy and location errors. Uncertainties in double-difference locations are improved by more than an order of magnitude compared to catalog locations. The algorithm is tested, and its performance is demonstrated on two clusters of earthquakes located on the northern Hayward fault, California. There it colapses the diffuse catalog locations into sharp images of seismicity and reveals horizontal lineations of hypocenter that define the narrow regions on the fault where stress is released by brittle failure.

Systems Study of an Automated Fire Weather Data System

NASA Technical Reports Server (NTRS)

Nishioka, K.

1974-01-01

A sensor system applicable to an automated weather station was developed. The sensor provides automated fire weather data which correlates with manual readings. The equipment and methods are applied as an aid to the surveillance and protection of wildlands from fire damage. The continuous readings provided by the sensor system make it possible to determine the periods of time that the wilderness areas should be closed to the public to minimize the possibilities of fire.

Feedback system design with an uncertain plant

NASA Technical Reports Server (NTRS)

Milich, D.; Valavani, L.; Athans, M.

1986-01-01

A method is developed to design a fixed-parameter compensator for a linear, time-invariant, SISO (single-input single-output) plant model characterized by significant structured, as well as unstructured, uncertainty. The controller minimizes the H(infinity) norm of the worst-case sensitivity function over the operating band and the resulting feedback system exhibits robust stability and robust performance. It is conjectured that such a robust nonadaptive control design technique can be used on-line in an adaptive control system.

SUBOPT: A CAD program for suboptimal linear regulators

NASA Technical Reports Server (NTRS)

Fleming, P. J.

1985-01-01

An interactive software package which provides design solutions for both standard linear quadratic regulator (LQR) and suboptimal linear regulator problems is described. Intended for time-invariant continuous systems, the package is easily modified to include sampled-data systems. LQR designs are obtained by established techniques while the large class of suboptimal problems containing controller and/or performance index options is solved using a robust gradient minimization technique. Numerical examples demonstrate features of the package and recent developments are described.

50Gb/s PAM-4 oxide VCSEL development progress at Broadcom

NASA Astrophysics Data System (ADS)

Wang, Jingyi; Murty, M. V. Ramana; Wang, Charlie; Hui, David; Lehman Harren, Ann; Chang, Hsu-Hao; Feng, Zheng-Wen; Fanning, Thomas R.; Sridhara, Aaditya; Taslim, Sumitro-Joyo; Cai, Xinle; Chu, Jason; Giovane, Laura M.

2017-02-01

This paper will review the device design and performance of Broadcom's 50Gb/s PAM-4 VCSEL to enable the next generation of transceivers using a PAM-4 advanced modulation scheme at 25-28 GBd. The VCSEL has been optimized to minimize noise and improve dynamic performance for cleaner eyes. Preliminary wear out lifetime studies indicate that the time to 1% failure exceeds 10 years, making the VCSELs suitable for data communication applications.

Develop Measures of Effectiveness and Deployment Optimization Rules for Networked Ground Micro-Sensors

DTIC Science & Technology

2001-05-01

types and total #) Ø Control of Sensors ( Scheduling ) Ø Coverage (Time & Area) Uncontrollable Inputs ØWeather Ø Atmospheric Effects Ø Equipment...are widely scattered and used to cue or wakeup other higher-level sensors. Trip line sensors consist of some combination of acoustic, seismic and...Employ a mix if different sensor types in order to increase detection probability 4.4.4.2 Minimize Battery Power • Set schedule turn on and off

Combinatorial therapy discovery using mixed integer linear programming.

PubMed

Pang, Kaifang; Wan, Ying-Wooi; Choi, William T; Donehower, Lawrence A; Sun, Jingchun; Pant, Dhruv; Liu, Zhandong

2014-05-15

Combinatorial therapies play increasingly important roles in combating complex diseases. Owing to the huge cost associated with experimental methods in identifying optimal drug combinations, computational approaches can provide a guide to limit the search space and reduce cost. However, few computational approaches have been developed for this purpose, and thus there is a great need of new algorithms for drug combination prediction. Here we proposed to formulate the optimal combinatorial therapy problem into two complementary mathematical algorithms, Balanced Target Set Cover (BTSC) and Minimum Off-Target Set Cover (MOTSC). Given a disease gene set, BTSC seeks a balanced solution that maximizes the coverage on the disease genes and minimizes the off-target hits at the same time. MOTSC seeks a full coverage on the disease gene set while minimizing the off-target set. Through simulation, both BTSC and MOTSC demonstrated a much faster running time over exhaustive search with the same accuracy. When applied to real disease gene sets, our algorithms not only identified known drug combinations, but also predicted novel drug combinations that are worth further testing. In addition, we developed a web-based tool to allow users to iteratively search for optimal drug combinations given a user-defined gene set. Our tool is freely available for noncommercial use at http://www.drug.liuzlab.org/. zhandong.liu@bcm.edu Supplementary data are available at Bioinformatics online.

Thin film and high-etch-rate type 248-nm bottom antireflective coatings

NASA Astrophysics Data System (ADS)

Enomoto, Tomoyuki; Takei, Satoshi; Kishioka, Takahiro; Hatanaka, Tadashi; Sakamoto, Rikimaru; Nakajima, Yasuyuki

2004-05-01

A frequent problem encountered by photoresists during the manufacturing of semiconductor device is that activating radiation is reflected back into the photoresist by the substrate. So, it is necessary that the light reflection is reduced from the substrate. One approach to reduce the light reflection is the use of bottom anti-reflective coating (BARC) applied to the substrate beneath the photoresist layer. The BARC technology has been utilized for a few years to minimize the reflectivity. As the chip size is reduced to sub 0.13 micron, the photoresist thickness has to decrease with the aspect ratio being less than 3.0. Therefore, new Organic BARC is strongly required which has the minimum reflectivity with thinner BARC thickness and higher etch selectivity toward resists. Nissan Chemical Industries, Ltd. and Brewer Science, Inc. have developed the advanced Organic BARC for achieving the above purpose. As a result, the suitable high performance NCA3000 series 248nm Organic BARCs were developed. Using CF4 gas as etchant, the plasma etch rate of NCA3000 series is about 1.4-1.6 times higher than that of conventional 248nm resists and 1.1-1.2 times higher than that of the existing product. The NCA3000 series can minimize the substrate reflectivity at below 45nm BARC thickness, shows excellent litho performance and coating properties.

A dynamic scheduling algorithm for singe-arm two-cluster tools with flexible processing times

NASA Astrophysics Data System (ADS)

Li, Xin; Fung, Richard Y. K.

2018-02-01

This article presents a dynamic algorithm for job scheduling in two-cluster tools producing multi-type wafers with flexible processing times. Flexible processing times mean that the actual times for processing wafers should be within given time intervals. The objective of the work is to minimize the completion time of the newly inserted wafer. To deal with this issue, a two-cluster tool is decomposed into three reduced single-cluster tools (RCTs) in a series based on a decomposition approach proposed in this article. For each single-cluster tool, a dynamic scheduling algorithm based on temporal constraints is developed to schedule the newly inserted wafer. Three experiments have been carried out to test the dynamic scheduling algorithm proposed, comparing with the results the 'earliest starting time' heuristic (EST) adopted in previous literature. The results show that the dynamic algorithm proposed in this article is effective and practical.

Value of 18F-FDG PET and PET/CT for evaluation of pediatric malignancies.

PubMed

Uslu, Lebriz; Donig, Jessica; Link, Michael; Rosenberg, Jarrett; Quon, Andrew; Daldrup-Link, Heike E

2015-02-01

Successful management of solid tumors in children requires imaging tests for accurate disease detection, characterization, and treatment monitoring. Technologic developments aim toward the creation of integrated imaging approaches that provide a comprehensive diagnosis with a single visit. These integrated diagnostic tests not only are convenient for young patients but also save direct and indirect health-care costs by streamlining procedures, minimizing hospitalizations, and minimizing lost school or work time for children and their parents. (18)F-FDG PET/CT is a highly sensitive and specific imaging modality for whole-body evaluation of pediatric malignancies. However, recent concerns about ionizing radiation exposure have led to a search for alternative imaging methods, such as whole-body MR imaging and PET/MR. As we develop new approaches for tumor staging, it is important to understand current benchmarks. This review article will synthesize the current literature on (18)F-FDG PET/CT for tumor staging in children, summarizing questions that have been solved and providing an outlook on unsolved avenues. © 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

Gear optimization

NASA Technical Reports Server (NTRS)

Vanderplaats, G. N.; Chen, Xiang; Zhang, Ning-Tian

1988-01-01

The use of formal numerical optimization methods for the design of gears is investigated. To achieve this, computer codes were developed for the analysis of spur gears and spiral bevel gears. These codes calculate the life, dynamic load, bending strength, surface durability, gear weight and size, and various geometric parameters. It is necessary to calculate all such important responses because they all represent competing requirements in the design process. The codes developed here were written in subroutine form and coupled to the COPES/ADS general purpose optimization program. This code allows the user to define the optimization problem at the time of program execution. Typical design variables include face width, number of teeth and diametral pitch. The user is free to choose any calculated response as the design objective to minimize or maximize and may impose lower and upper bounds on any calculated responses. Typical examples include life maximization with limits on dynamic load, stress, weight, etc. or minimization of weight subject to limits on life, dynamic load, etc. The research codes were written in modular form for easy expansion and so that they could be combined to create a multiple reduction optimization capability in future.

Endoscopic-assisted osteotomies for the treatment of craniosynostosis.

PubMed

Hinojosa, J; Esparza, J; Muñoz, M J

2007-12-01

The development of multidisciplinar units for Craniofacial Surgery has led to better postoperative results and a considerable decrease in morbidity in the treatment of complex craniofacial patients. Standard correction of craniosynostosis involves calvarial remodeling, often considerable blood losses that need to be replaced and lengthy hospital stay. The use of minimally invasive techniques for the correction of some of these malformations are widespread and allows the surgeon to minimize the incidence of complications by means of a decreased surgical time, blood salvage, and shortening of postoperative hospitalization in comparison to conventional craniofacial techniques. Simple and milder craniosynostosis are best approached by endoscopy-assisted osteotomies and render the best results. Extended procedures other than simple suturectomies have been described for more severe patients. Different osteotomies resembling standard fronto-orbital have been developed for the correction, and the use of postoperative cranial orthesis may improve the final cosmetic appearance. Thus, endoscopic-assisted procedures differ from the simple strategy of single suture resection that rendered insufficient results in the past, and different approaches can be tailored to solve these cases in patients in the setting of a case-to-case bases.

An integrated and pragmatic approach: Global plant safety management

NASA Astrophysics Data System (ADS)

McNutt, Jack; Gross, Andrew

1989-05-01

The Bhopal disaster in India in 1984 has compelled manufacturing companies to review their operations in order to minimize their risk exposure. Much study has been done on the subject of risk assessment and in refining safety reviews of plant operations. However, little work has been done to address the broader needs of decision makers in the multinational environment. The corporate headquarters of multinational organizations are concerned with identifying vulnerable areas to assure that appropriate risk-minimization measures are in force or will be taken. But the task of screening global business units for safety prowess is complicated and time consuming. This article takes a step towards simplifying this process by presenting the decisional model developed by the authors. Beginning with an overview of key issues affecting global safety management, the focus shifts to the multinational vulnerability model developed by the authors, which reflects an integration of approaches. The article concludes with a discussion of areas for further research. While the global chemical industry and major incidents therein are used for illustration, the procedures and solutions suggested here are applicable to all manufacturing operations.

Stochastic Optimization in The Power Management of Bottled Water Production Planning

NASA Astrophysics Data System (ADS)

Antoro, Budi; Nababan, Esther; Mawengkang, Herman

2018-01-01

This paper review a model developed to minimize production costs on bottled water production planning through stochastic optimization. As we know, that planning a management means to achieve the goal that have been applied, since each management level in the organization need a planning activities. The built models is a two-stage stochastic models that aims to minimize the cost on production of bottled water by observing that during the production process, neither interfernce nor vice versa occurs. The models were develop to minimaze production cost, assuming the availability of packing raw materials used considered to meet for each kind of bottles. The minimum cost for each kind production of bottled water are expressed in the expectation of each production with a scenario probability. The probability of uncertainly is a representation of the number of productions and the timing of power supply interruption. This is to ensure that the number of interruption that occur does not exceed the limit of the contract agreement that has been made by the company with power suppliers.

Augmented reality in surgical procedures

NASA Astrophysics Data System (ADS)

Samset, E.; Schmalstieg, D.; Vander Sloten, J.; Freudenthal, A.; Declerck, J.; Casciaro, S.; Rideng, Ø.; Gersak, B.

2008-02-01

Minimally invasive therapy (MIT) is one of the most important trends in modern medicine. It includes a wide range of therapies in videoscopic surgery and interventional radiology and is performed through small incisions. It reduces hospital stay-time by allowing faster recovery and offers substantially improved cost-effectiveness for the hospital and the society. However, the introduction of MIT has also led to new problems. The manipulation of structures within the body through small incisions reduces dexterity and tactile feedback. It requires a different approach than conventional surgical procedures, since eye-hand co-ordination is not based on direct vision, but more predominantly on image guidance via endoscopes or radiological imaging modalities. ARIS*ER is a multidisciplinary consortium developing a new generation of decision support tools for MIT by augmenting visual and sensorial feedback. We will present tools based on novel concepts in visualization, robotics and haptics providing tailored solutions for a range of clinical applications. Examples from radio-frequency ablation of liver-tumors, laparoscopic liver surgery and minimally invasive cardiac surgery will be presented. Demonstrators were developed with the aim to provide a seamless workflow for the clinical user conducting image-guided therapy.

Determinants of physical activity in minimally impaired people with multiple sclerosis.

PubMed

Kahraman, Turhan; Savci, Sema; Coskuner-Poyraz, Esra; Ozakbas, Serkan; Idiman, Egemen

2015-11-01

Despite the commonly known benefits of physical activity, evidence shows that people with multiple sclerosis (pwMS) are relatively inactive. There are several studies about factors affecting physical activity in pwMS. However, these factors have not investigated in minimally impaired pwMS who do not have remarkable symptoms and walking disturbance. The objective was to determine factors affecting physical activity in minimally impaired pwMS. We recruited 52 minimally impaired pwMS and measured physical activity with Godin Leisure-Time Exercise Questionnaire (GLTEQ) and an accelerometer used for the 7-day period. Demographic data were recorded. Walking (speed, endurance, dexterity, and quality), fatigue, depression, and quality of life were measured. We recruited 52 minimally impaired pwMS and measured physical activity with Godin Leisure-Time Exercise Questionnaire (GLTEQ) and an accelerometer used for the 7-day period. Demographic data were recorded. Walking (speed, endurance, dexterity, and quality), fatigue, depression, and quality of life were measured. The walking speed assessed by the Timed 25-Foot Walk and gender were found the determinants of physical activity level assessed by the GLTEQ and accelerometer, respectively. Walking (speed, endurance, and dexterity), gender, employment status, and quality of life were associated with physical activity. Either female or unemployed participants had significantly less physical activity. There were no significant difference between physical activity levels and the other subgroups. Either to be a female or to have slower walking speed was associated with less physical activity. Strategies to improve walking should be focused on female pwMS with minimal impairment. Copyright © 2015 Elsevier B.V. All rights reserved.

Reinforcement-learning-based dual-control methodology for complex nonlinear discrete-time systems with application to spark engine EGR operation.

PubMed

Shih, Peter; Kaul, Brian C; Jagannathan, S; Drallmeier, James A

2008-08-01

A novel reinforcement-learning-based dual-control methodology adaptive neural network (NN) controller is developed to deliver a desired tracking performance for a class of complex feedback nonlinear discrete-time systems, which consists of a second-order nonlinear discrete-time system in nonstrict feedback form and an affine nonlinear discrete-time system, in the presence of bounded and unknown disturbances. For example, the exhaust gas recirculation (EGR) operation of a spark ignition (SI) engine is modeled by using such a complex nonlinear discrete-time system. A dual-controller approach is undertaken where primary adaptive critic NN controller is designed for the nonstrict feedback nonlinear discrete-time system whereas the secondary one for the affine nonlinear discrete-time system but the controllers together offer the desired performance. The primary adaptive critic NN controller includes an NN observer for estimating the states and output, an NN critic, and two action NNs for generating virtual control and actual control inputs for the nonstrict feedback nonlinear discrete-time system, whereas an additional critic NN and an action NN are included for the affine nonlinear discrete-time system by assuming the state availability. All NN weights adapt online towards minimization of a certain performance index, utilizing gradient-descent-based rule. Using Lyapunov theory, the uniformly ultimate boundedness (UUB) of the closed-loop tracking error, weight estimates, and observer estimates are shown. The adaptive critic NN controller performance is evaluated on an SI engine operating with high EGR levels where the controller objective is to reduce cyclic dispersion in heat release while minimizing fuel intake. Simulation and experimental results indicate that engine out emissions drop significantly at 20% EGR due to reduction in dispersion in heat release thus verifying the dual-control approach.

Defining the Pros and Cons of Open, Conventional Laparoscopy, and Robot-Assisted Pyeloplasty in a Developing Nation

PubMed Central

Pahwa, Archna R.; Girotra, Mohit; Abrahm, Rtika Ryfka; Kathuria, Sachin; Sharma, Ajay

2014-01-01

Introduction. Congenital pelviureteric junction obstruction (PUJO) is one of the most common causes of hydronephrosis. Historically, open dismembered pyeloplasty has been considered the gold standard intervention for correcting PUJO. The aim of this study was to compare the surgical and functional outcomes of three different approaches, namely, open, conventional laparoscopy, and robotic pyeloplasty. Material and Methods. 60 patients underwent minimally invasive pyeloplasty (30 conventional laparoscopies and 30 robotics) for congenital PUJO at a tertiary health center in India. Demographic, perioperative, and postoperative data were prospectively collected and analyzed. The data of these patients were retrospectively compared with another cohort of 30 patients who had undergone open pyeloplasty. Results. There was significant difference in operative time, time to drain removal, hospital stay, pain score, and complications rate between open and minimally invasive pyeloplasty (P < 0.05). SFI was considerably lesser in robotic as compared to conventional laparoscopy. The success rate in OP, CLP, and RP was 93.33, 96.67, and 96.67%. Conclusion. Robotic pyeloplasty is safe, effective, and feasible. It is associated with significantly lesser operative time, lesser blood loss, less pain, shorter hospital stay, and fewer complications. It is also associated with considerably lesser surgeon fatigue as compared to conventional laparoscopy pyeloplasty. PMID:24624138

Results of a randomized trial of HERMES-assisted versus non-HERMES-assisted laparoscopic antireflux surgery.

PubMed

Luketich, J D; Fernando, H C; Buenaventura, P O; Christie, N A; Grondin, S C; Schauer, P R

2002-09-01

Speech recognition technology is a recent development in minimally invasive surgery. This study was designed to assess the impact of HERMES on operating room efficiency and user satisfaction. Patients undergoing laparoscopic antireflux operations by surgeons experienced in minimally invasive surgery were randomized to HERMES-assisted or standard laparoscopic operations. The variables of interest were circulating nurse's time spent adjusting devices that are voice-controlled by HERMES, number of adjustments to devices requested, and surgeon and nurse satisfaction measured on a scale from 1 (dissatisfied) to 10 (satisfied). A total of 30 cases were studied. In the non-HERMES cases, nurses were interrupted to make device adjustments an average of 15.3 times per case versus 0.33 times per case in the with-HERMES cases (p < 0.01). The interruptions during the non-HERMES cases averaged 4.35 min per case versus 0.16 min per case in the with-HERMES cases (p = 0.03). Average satisfaction scores for HERMES operations as opposed to non-HERMES operations were 9.2 versus 5.3 for nurses (p < 0.01) and 9.0 versus 5.1 for surgeons (p < 0.01). Physician and nurse acceptance of HERMES was very high because of the smoother interruption-free environment.

Increasing accuracy of dispersal kernels in grid-based population models

USGS Publications Warehouse

Slone, D.H.

2011-01-01

Dispersal kernels in grid-based population models specify the proportion, distance and direction of movements within the model landscape. Spatial errors in dispersal kernels can have large compounding effects on model accuracy. Circular Gaussian and Laplacian dispersal kernels at a range of spatial resolutions were investigated, and methods for minimizing errors caused by the discretizing process were explored. Kernels of progressively smaller sizes relative to the landscape grid size were calculated using cell-integration and cell-center methods. These kernels were convolved repeatedly, and the final distribution was compared with a reference analytical solution. For large Gaussian kernels (σ > 10 cells), the total kernel error was <10 &sup-11; compared to analytical results. Using an invasion model that tracked the time a population took to reach a defined goal, the discrete model results were comparable to the analytical reference. With Gaussian kernels that had σ ≤ 0.12 using the cell integration method, or σ ≤ 0.22 using the cell center method, the kernel error was greater than 10%, which resulted in invasion times that were orders of magnitude different than theoretical results. A goal-seeking routine was developed to adjust the kernels to minimize overall error. With this, corrections for small kernels were found that decreased overall kernel error to <10-11 and invasion time error to <5%.

Laser Drilling Development Trial Final Report CRADA No. TSB-1538-98

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hermann, M. R.; Hebbar, R. R.

This project performed various laser drilling tests to demonstrate femtosecond laser drilling of fuel injector nozzles with minimal recast, minimal heat affected zone and no collateral damage. LLNL had extensive experience in ultra short-pulse laser systems and developed specialized hardware for these applications.

Interdependent Network Recovery Games.

PubMed

Smith, Andrew M; González, Andrés D; Dueñas-Osorio, Leonardo; D'Souza, Raissa M

2017-10-30

Recovery of interdependent infrastructure networks in the presence of catastrophic failure is crucial to the economy and welfare of society. Recently, centralized methods have been developed to address optimal resource allocation in postdisaster recovery scenarios of interdependent infrastructure systems that minimize total cost. In real-world systems, however, multiple independent, possibly noncooperative, utility network controllers are responsible for making recovery decisions, resulting in suboptimal decentralized processes. With the goal of minimizing recovery cost, a best-case decentralized model allows controllers to develop a full recovery plan and negotiate until all parties are satisfied (an equilibrium is reached). Such a model is computationally intensive for planning and negotiating, and time is a crucial resource in postdisaster recovery scenarios. Furthermore, in this work, we prove this best-case decentralized negotiation process could continue indefinitely under certain conditions. Accounting for network controllers' urgency in repairing their system, we propose an ad hoc sequential game-theoretic model of interdependent infrastructure network recovery represented as a discrete time noncooperative game between network controllers that is guaranteed to converge to an equilibrium. We further reduce the computation time needed to find a solution by applying a best-response heuristic and prove bounds on ε-Nash equilibrium, where ε depends on problem inputs. We compare best-case and ad hoc models on an empirical interdependent infrastructure network in the presence of simulated earthquakes to demonstrate the extent of the tradeoff between optimality and computational efficiency. Our method provides a foundation for modeling sociotechnical systems in a way that mirrors restoration processes in practice. © 2017 Society for Risk Analysis.

A field investigation of concrete patches containing pyrament blended concrete.

DOT National Transportation Integrated Search

1994-01-01

During roadway repairs, state highway officials try to minimize lane closure times. This reduces inconvenience to travelers, reduces traffic control needs, and helps minimize work zone accidents. For rapid repairs, materials that provide high early s...

Virtual Exercise Training Software System

NASA Technical Reports Server (NTRS)

Vu, L.; Kim, H.; Benson, E.; Amonette, W. E.; Barrera, J.; Perera, J.; Rajulu, S.; Hanson, A.

2018-01-01

The purpose of this study was to develop and evaluate a virtual exercise training software system (VETSS) capable of providing real-time instruction and exercise feedback during exploration missions. A resistive exercise instructional system was developed using a Microsoft Kinect depth-camera device, which provides markerless 3-D whole-body motion capture at a small form factor and minimal setup effort. It was hypothesized that subjects using the newly developed instructional software tool would perform the deadlift exercise with more optimal kinematics and consistent technique than those without the instructional software. Following a comprehensive evaluation in the laboratory, the system was deployed for testing and refinement in the NASA Extreme Environment Mission Operations (NEEMO) analog.

Support Minimized Inversion of Acoustic and Elastic Wave Scattering

NASA Astrophysics Data System (ADS)

Safaeinili, Ali

Inversion of limited data is common in many areas of NDE such as X-ray Computed Tomography (CT), Ultrasonic and eddy current flaw characterization and imaging. In many applications, it is common to have a bias toward a solution with minimum (L^2)^2 norm without any physical justification. When it is a priori known that objects are compact as, say, with cracks and voids, by choosing "Minimum Support" functional instead of the minimum (L^2)^2 norm, an image can be obtained that is equally in agreement with the available data, while it is more consistent with what is most probably seen in the real world. We have utilized a minimum support functional to find a solution with the smallest volume. This inversion algorithm is most successful in reconstructing objects that are compact like voids and cracks. To verify this idea, we first performed a variational nonlinear inversion of acoustic backscatter data using minimum support objective function. A full nonlinear forward model was used to accurately study the effectiveness of the minimized support inversion without error due to the linear (Born) approximation. After successful inversions using a full nonlinear forward model, a linearized acoustic inversion was developed to increase speed and efficiency in imaging process. The results indicate that by using minimum support functional, we can accurately size and characterize voids and/or cracks which otherwise might be uncharacterizable. An extremely important feature of support minimized inversion is its ability to compensate for unknown absolute phase (zero-of-time). Zero-of-time ambiguity is a serious problem in the inversion of the pulse-echo data. The minimum support inversion was successfully used for the inversion of acoustic backscatter data due to compact scatterers without the knowledge of the zero-of-time. The main drawback to this type of inversion is its computer intensiveness. In order to make this type of constrained inversion available for common use, work needs to be performed in three areas: (1) exploitation of state-of-the-art parallel computation, (2) improvement of theoretical formulation of the scattering process for better computation efficiency, and (3) development of better methods for guiding the non-linear inversion. (Abstract shortened by UMI.).

Minimization of Ohmic Losses for Domain Wall Motion in a Ferromagnetic Nanowire

NASA Astrophysics Data System (ADS)

Tretiakov, O. A.; Liu, Y.; Abanov, Ar.

2010-11-01

We study current-induced domain-wall motion in a narrow ferromagnetic wire. We propose a way to move domain walls with a resonant time-dependent current which dramatically decreases the Ohmic losses in the wire and allows driving of the domain wall with higher speed without burning the wire. For any domain-wall velocity we find the time dependence of the current needed to minimize the Ohmic losses. Below a critical domain-wall velocity specified by the parameters of the wire the minimal Ohmic losses are achieved by dc current. Furthermore, we identify the wire parameters for which the losses reduction from its dc value is the most dramatic.

Project Plan for Recreation Resources Development. North Hartland Lake, Hartland and Hartford, Vermont.

DTIC Science & Technology

1981-01-01

of reservoir management are included within the scope of thle project plan. The plan represents a culmination of knowledge gathered from past...a detailed inventory and analysis of the projects natural resources in order to minimize environment and aesthetic impact, promote logical development...and minimize development costs. Factors inventoried included soil types, vegetation, topography, wildlife, surface geology, historical

Discriminative validity of the Minimally Invasive Surgical Trainer in Virtual Reality (MIST-VR) using criteria levels based on expert performance.

PubMed

Gallagher, A G; Lederman, A B; McGlade, K; Satava, R M; Smith, C D

2004-04-01

Increasing constraints on the time and resources needed to train surgeons have led to a new emphasis on finding innovative ways to teach surgical skills outside the operating room. Virtual reality training has been proposed as a method to both instruct surgical students and evaluate the psychomotor components of minimally invasive surgery ex vivo. The performance of 100 laparoscopic novices was compared to that of 12 experienced (>50 minimally invasive procedures) and 12 inexperienced (<10 minimally invasive procedures) laparoscopic surgeons. The values of the experienced surgeons' performance were used as benchmark comparators (or criterion measures). Each subject completed six tasks on the Minimally Invasive Surgical Trainer-Virtual Reality (MIST-VR) three times. The outcome measures were time to complete the task, number of errors, economy of instrument movement, and economy of diathermy. After three trials, the mean performance of the medical students approached that of the experienced surgeons. However, 7-27% of the scores of the students fell more than two SD below the mean scores of the experienced surgeons (the criterion level). The MIST-VR system is capable of evaluating the psychomotor skills necessary in laparoscopic surgery and discriminating between experts and novices. Furthermore, although some novices improved their skills quickly, a subset had difficulty acquiring the psychomotor skills. The MIST-VR may be useful in identifying that subset of novices.

[THE COMPARISON OF RESULTS OF DETECTION OF MINIMAL RESIDUAL DISEASE IN PERIPHERAL BLOOD AND MARROW IN CHILDREN OF THE FIRST YEAR OF LIFE WITH ACUTE LYMPHOBLASTIC LEUCOSIS].

PubMed

Tsaur, G A; Riger, T O; Popov, A M; Nasedkina, T V; Kustanovich, A M; Solodovnikov, A G; Streneva, O V; Shorikov, E V; Tsvirenko, S V; Saveliev, L I; Fechina, L G

2015-04-01

The occurrence of minimal residual disease is an important prognostic factor under acute lymphoblastic leucosis in children and adults. In overwhelming majority of research studies bone marrow is used to detect minimal residual disease. The comparative characteristic of detection of minimal residual disease in peripheral blood and bone marrow was carried out. The prognostic role of occurrence of minimal residual disease in peripheral blood and bone marrow under therapy according protocol MLL-Baby was evaluated. The analysis embraced 142 pair samples from 53 patients with acute lymphoblastic leucosis and various displacements of gene MLL younger than 365 days. The minimal residual disease was detected by force of identification of chimeric transcripts using polymerase chain reaction in real-time mode in 7 sequential points of observation established by protocol of therapy. The comparability of results of qualitative detection of minimal residual disease in bone marrow and peripheral blood amounted to 84.5%. At that, in all 22 (15.5%) discordant samples minimal residual disease was detected only in bone marrow. Despite of high level of comparability of results of detection of minimal residual disease in peripheral blood and bone marrow the occurrence of minimal residual disease in peripheral blood at various stages of therapy demonstrated no independent prognostic significance. The established differences had no relationship with sensitivity of method determined by value of absolute expression of gene ABL. Most likely, these differences reflected real distribution of tumor cells. The results of study demonstrated that application of peripheral blood instead of bone marrow for monitoring of minimal residual disease under acute lymphoblastic leucosis in children of first year of life is inappropriate. At the same time, retention of minimal residual disease in TH4 in bone marrow was an independent and prognostic unfavorable factor under therapy of acute lymphoblastic leucosis of children of first year of life according protocol MLL-Baby (OO=7.326, confidence interval 2.378-22.565).

Development of a Compact Rectenna for Wireless Powering of a Head-Mountable Deep Brain Stimulation Device

PubMed Central

Kouzani, Abbas Z.; Tye, Susannah J.; Abulseoud, Osama A.; Amiet, Andrew; Galehdar, Amir; Kaynak, Akif; Berk, Michael

2014-01-01

Design of a rectangular spiral planar inverted-F antenna (PIFA) at 915 MHz for wireless power transmission applications is proposed. The antenna and rectifying circuitry form a rectenna, which can produce dc power from a distant radio frequency energy transmitter. The generated dc power is used to operate a low-power deep brain stimulation pulse generator. The proposed antenna has the dimensions of 10 mm \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$\\times\\,$ \\end{document}12.5 mm \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$\\times\\,$ \\end{document}1.5 mm and resonance frequency of 915 MHz with a measured bandwidth of 15 MHz at return loss of \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}${-}{\\rm 10}~{\\rm dB}$ \\end{document}. A dielectric substrate of FR-4 of \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$\\varepsilon _{r}=4.8$ \\end{document} and \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$\\delta=0.015$ \\end{document} with thickness of 1.5 mm is used for both antenna and rectifier circuit simulation and fabrication because of its availability and low cost. An L-section impedance matching circuit is used between the PIFA and voltage doubler rectifier. The impedance matching circuit also works as a low-pass filter for elimination of higher order harmonics. Maximum dc voltage at the rectenna output is 7.5 V in free space and this rectenna can drive a deep brain stimulation pulse generator at a distance of 30 cm from a radio frequency energy transmitter, which transmits power of 26.77 dBm. PMID:27170863

Citrus flush shoot ontogeny modulates biotic potential of Diaphorina citri.

PubMed

Cifuentes-Arenas, Juan Camilo; de Goes, António; de Miranda, Marcelo Pedreira; Beattie, George Andrew Charles; Lopes, Silvio Aparecido

2018-01-01

The biology and behaviour of the psyllid Diaphorina citri Kuwayama (Hemiptera: Sternorrhyncha: Liviidae), the major insect vector of bacteria associated with huanglongbing, have been extensively studied with respect to host preferences, thermal requirements, and responses to visual and chemical volatile stimuli. However, development of the psyllid in relation to the ontogeny of immature citrus flush growth has not been clearly defined or illustrated. Such information is important for determining the timing and frequency of measures used to minimize populations of the psyllid in orchards and spread of HLB. Our objective was to study how flush ontogeny influences the biotic potential of the psyllid. We divided citrus flush growth into six stages within four developmental phases: emergence (V1), development (V2 and V3), maturation (V4 and V5), and dormancy (V6). Diaphorina citri oviposition and nymph development were assessed on all flush stages in a temperature controlled room, and in a screen-house in which ambient temperatures varied. Our results show that biotic potential of Diaphorina citri is not a matter of the size or the age of the flushes (days after budbreak), but the developmental stage within its ontogeny. Females laid eggs on flush V1 to V5 only, with the time needed to commence oviposition increasing with the increasing in flush age. Stages V1, V2 and V3 were most suitable for oviposition, nymph survival and development, and adult emergence, which showed evidence of protandry. Flush shoots at emerging and developmental phases should be the focus of any chemical or biological control strategy to reduce the biotic potential of D. citri, to protect citrus tree from Liberibacter infection and to minimize HLB dissemination.

Citrus flush shoot ontogeny modulates biotic potential of Diaphorina citri

PubMed Central

de Goes, António; de Miranda, Marcelo Pedreira

2018-01-01

The biology and behaviour of the psyllid Diaphorina citri Kuwayama (Hemiptera: Sternorrhyncha: Liviidae), the major insect vector of bacteria associated with huanglongbing, have been extensively studied with respect to host preferences, thermal requirements, and responses to visual and chemical volatile stimuli. However, development of the psyllid in relation to the ontogeny of immature citrus flush growth has not been clearly defined or illustrated. Such information is important for determining the timing and frequency of measures used to minimize populations of the psyllid in orchards and spread of HLB. Our objective was to study how flush ontogeny influences the biotic potential of the psyllid. We divided citrus flush growth into six stages within four developmental phases: emergence (V1), development (V2 and V3), maturation (V4 and V5), and dormancy (V6). Diaphorina citri oviposition and nymph development were assessed on all flush stages in a temperature controlled room, and in a screen-house in which ambient temperatures varied. Our results show that biotic potential of Diaphorina citri is not a matter of the size or the age of the flushes (days after budbreak), but the developmental stage within its ontogeny. Females laid eggs on flush V1 to V5 only, with the time needed to commence oviposition increasing with the increasing in flush age. Stages V1, V2 and V3 were most suitable for oviposition, nymph survival and development, and adult emergence, which showed evidence of protandry. Flush shoots at emerging and developmental phases should be the focus of any chemical or biological control strategy to reduce the biotic potential of D. citri, to protect citrus tree from Liberibacter infection and to minimize HLB dissemination. PMID:29304052

Optimal protocols for slowly driven quantum systems.

PubMed

Zulkowski, Patrick R; DeWeese, Michael R

2015-09-01

The design of efficient quantum information processing will rely on optimal nonequilibrium transitions of driven quantum systems. Building on a recently developed geometric framework for computing optimal protocols for classical systems driven in finite time, we construct a general framework for optimizing the average information entropy for driven quantum systems. Geodesics on the parameter manifold endowed with a positive semidefinite metric correspond to protocols that minimize the average information entropy production in finite time. We use this framework to explicitly compute the optimal entropy production for a simple two-state quantum system coupled to a heat bath of bosonic oscillators, which has applications to quantum annealing.

Discrete-time model reduction in limited frequency ranges

NASA Technical Reports Server (NTRS)

Horta, Lucas G.; Juang, Jer-Nan; Longman, Richard W.

1991-01-01

A mathematical formulation for model reduction of discrete time systems such that the reduced order model represents the system in a particular frequency range is discussed. The algorithm transforms the full order system into balanced coordinates using frequency weighted discrete controllability and observability grammians. In this form a criterion is derived to guide truncation of states based on their contribution to the frequency range of interest. Minimization of the criterion is accomplished without need for numerical optimization. Balancing requires the computation of discrete frequency weighted grammians. Close form solutions for the computation of frequency weighted grammians are developed. Numerical examples are discussed to demonstrate the algorithm.