Science.gov

Sample records for additional design constraints

  1. Straightness error evaluation of additional constraints

    NASA Astrophysics Data System (ADS)

    Pei, Ling; Wang, Shenghuai; Liu, Yong

    2011-05-01

    A new generation of Dimensional and Geometrical Product Specifications (GPS) and Verification standard system is based on both the Mathematical structure and the Metrology. To determine the eligibility of the product should be adapt to modern digital measuring instruments. But in mathematizating measurement when the geometric tolerance specifications has additional constraints requirement, such as straightness with an additional constraint, required to qualify the additional form requirements of the feature within the tolerance zone. Knowing how to close the geometrical specification to the functional specification will result in the correctness of measurement results. Adopting the methodology to evaluate by analyzing various forms including the ideal features and the extracted features and their combinations in an additional form constraint of the straightness in tolerance zone had been found correctly acceptance decision for products. The results show that different combinations of the various forms had affected acceptance on the product qualification and the appropriate forms matching can meet the additional form requirements for product features.

  2. Straightness error evaluation of additional constraints

    NASA Astrophysics Data System (ADS)

    Pei, Ling; Wang, Shenghuai; Liu, Yong

    2010-12-01

    A new generation of Dimensional and Geometrical Product Specifications (GPS) and Verification standard system is based on both the Mathematical structure and the Metrology. To determine the eligibility of the product should be adapt to modern digital measuring instruments. But in mathematizating measurement when the geometric tolerance specifications has additional constraints requirement, such as straightness with an additional constraint, required to qualify the additional form requirements of the feature within the tolerance zone. Knowing how to close the geometrical specification to the functional specification will result in the correctness of measurement results. Adopting the methodology to evaluate by analyzing various forms including the ideal features and the extracted features and their combinations in an additional form constraint of the straightness in tolerance zone had been found correctly acceptance decision for products. The results show that different combinations of the various forms had affected acceptance on the product qualification and the appropriate forms matching can meet the additional form requirements for product features.

  3. Optimality criteria design and stress constraint processing

    NASA Technical Reports Server (NTRS)

    Levy, R.

    1982-01-01

    Methods for pre-screening stress constraints into either primary or side-constraint categories are reviewed; a projection method, which is developed from prior cycle stress resultant history, is introduced as an additional screening parameter. Stress resultant projections are also employed to modify the traditional stress-ratio, side-constraint boundary. A special application of structural modification reanalysis is applied to the critical stress constraints to provide feasible designs that are preferable to those obtained by conventional scaling. Sample problem executions show relatively short run times and fewer design cycle iterations to achieve low structural weights; those attained are comparable to the minimum values developed elsewhere.

  4. Stress constraints in optimality criteria design

    NASA Technical Reports Server (NTRS)

    Levy, R.

    1982-01-01

    Procedures described emphasize the processing of stress constraints within optimality criteria designs for low structural weight with stress and compliance constraints. Prescreening criteria are used to partition stress constraints into either potentially active primary sets or passive secondary sets that require minimal processing. Side constraint boundaries for passive constraints are derived by projections from design histories to modify conventional stress-ratio boundaries. Other procedures described apply partial structural modification reanalysis to design variable groups to correct stress constraint violations of unfeasible designs. Sample problem results show effective design convergence and, in particular, advantages for reanalysis in obtaining lower feasible design weights.

  5. Hard and Soft Constraints in Reliability-Based Design Optimization

    NASA Technical Reports Server (NTRS)

    Crespo, L.uis G.; Giesy, Daniel P.; Kenny, Sean P.

    2006-01-01

    This paper proposes a framework for the analysis and design optimization of models subject to parametric uncertainty where design requirements in the form of inequality constraints are present. Emphasis is given to uncertainty models prescribed by norm bounded perturbations from a nominal parameter value and by sets of componentwise bounded uncertain variables. These models, which often arise in engineering problems, allow for a sharp mathematical manipulation. Constraints can be implemented in the hard sense, i.e., constraints must be satisfied for all parameter realizations in the uncertainty model, and in the soft sense, i.e., constraints can be violated by some realizations of the uncertain parameter. In regard to hard constraints, this methodology allows (i) to determine if a hard constraint can be satisfied for a given uncertainty model and constraint structure, (ii) to generate conclusive, formally verifiable reliability assessments that allow for unprejudiced comparisons of competing design alternatives and (iii) to identify the critical combination of uncertain parameters leading to constraint violations. In regard to soft constraints, the methodology allows the designer (i) to use probabilistic uncertainty models, (ii) to calculate upper bounds to the probability of constraint violation, and (iii) to efficiently estimate failure probabilities via a hybrid method. This method integrates the upper bounds, for which closed form expressions are derived, along with conditional sampling. In addition, an l(sub infinity) formulation for the efficient manipulation of hyper-rectangular sets is also proposed.

  6. Design Constraints on a Synthetic Metabolism

    PubMed Central

    Bilgin, Tugce; Wagner, Andreas

    2012-01-01

    A metabolism is a complex network of chemical reactions that converts sources of energy and chemical elements into biomass and other molecules. To design a metabolism from scratch and to implement it in a synthetic genome is almost within technological reach. Ideally, a synthetic metabolism should be able to synthesize a desired spectrum of molecules at a high rate, from multiple different nutrients, while using few chemical reactions, and producing little or no waste. Not all of these properties are achievable simultaneously. We here use a recently developed technique to create random metabolic networks with pre-specified properties to quantify trade-offs between these and other properties. We find that for every additional molecule to be synthesized a network needs on average three additional reactions. For every additional carbon source to be utilized, it needs on average two additional reactions. Networks able to synthesize 20 biomass molecules from each of 20 alternative sole carbon sources need to have at least 260 reactions. This number increases to 518 reactions for networks that can synthesize more than 60 molecules from each of 80 carbon sources. The maximally achievable rate of biosynthesis decreases by approximately 5 percent for every additional molecule to be synthesized. Biochemically related molecules can be synthesized at higher rates, because their synthesis produces less waste. Overall, the variables we study can explain 87 percent of variation in network size and 84 percent of the variation in synthesis rate. The constraints we identify prescribe broad boundary conditions that can help to guide synthetic metabolism design. PMID:22768162

  7. Design of helicopter rotors to noise constraints

    NASA Technical Reports Server (NTRS)

    Schaeffer, E. G.; Sternfeld, H., Jr.

    1978-01-01

    Results of the initial phase of a research project to study the design constraints on helicopter noise are presented. These include the calculation of nonimpulsive rotor harmonic and broadband hover noise spectra, over a wide range of rotor design variables and the sensitivity of perceived noise level (PNL) to changes in rotor design parameters. The prediction methodology used correlated well with measured whirl tower data. Application of the predictions to variations in rotor design showed tip speed and thrust as having the most effect on changing PNL.

  8. Decoupling Coupled Constraints Through Utility Design

    SciTech Connect

    Li, N; Marden, JR

    2014-08-01

    Several multiagent systems exemplify the need for establishing distributed control laws that ensure the resulting agents' collective behavior satisfies a given coupled constraint. This technical note focuses on the design of such control laws through a game-theoretic framework. In particular, this technical note provides two systematic methodologies for the design of local agent objective functions that guarantee all resulting Nash equilibria optimize the system level objective while also satisfying a given coupled constraint. Furthermore, the designed local agent objective functions fit into the framework of state based potential games. Consequently, one can appeal to existing results in game-theoretic learning to derive a distributed process that guarantees the agents will reach such an equilibrium.

  9. Incorporating manufacturability constraints into the design process of heterogeneous objects

    NASA Astrophysics Data System (ADS)

    Hu, Yuna; Blouin, Vincent Y.; Fadel, Georges M.

    2004-11-01

    Rapid prototyping (RP) technology, such as Laser Engineering Net Shaping (LENSTM), can be used to fabricate heterogeneous objects with gradient variations in material composition. These objects are generally characterized by enhanced functional performance. Past research on the design of such objects has focused on representation, modeling, and functional performance. However, the inherent constraints in RP processes, such as system capability and processing time, lead to heterogeneous objects that may not meet the designer's original intent. To overcome this situation, the research presented in this paper focuses on the identification and implementation of manufacturing constraints into the design process. A node-based finite element modeling technique is used for the representation and analysis and the multicriteria design problem corresponds to finding the nodal material compositions that minimize structural weight and maximize thermal performance. The optimizer used in this research is a real-valued Evolutionary Strategies (ES), which is well suited for this type of multi-modal problem. Two limitations of the LENS manufacturing process, which have an impact on the design process, are identified and implemented. One of them is related to the manufacturing time, which is considered as an additional criterion to be minimized in the design problem for a preselected tool path. A brake disc rotor made of two materials, aluminum for lightweight and steel for superior thermal characteristics, is used to illustrate the tradeoff between manufacturability and functionality.

  10. Study of design constraints on helicopter noise

    NASA Technical Reports Server (NTRS)

    Sternfeld, H., Jr.; Wiedersum, C. W.

    1979-01-01

    A means of estimating the noise generated by a helicopter main rotor using information which is generally available during the preliminary design phase of aircraft development is presented. The method utilizes design charts and tables which do not require an understanding of acoustical theory or computational procedures in order to predict the perceived noise level, a weighted sound pressure level, or C weighted sound pressure level of a single hovering rotor. A method for estimating the effective perceived noise level in forward flight is also included. In order to give the designer an assessment of the relative rotor performance, which may be traded off against noise, an additional chart for estimating the percent of available rotor thrust which must be expended in lifting the rotor and drive system, is included as well as approach for comparing the subjective acceptability of various rotors once the absolute sound pressure levels are predicted.

  11. WINDOWAC (Wing Design Optimization With Aeroelastic Constraints): Program manual

    NASA Technical Reports Server (NTRS)

    Haftka, R. T.; Starnes, J. H., Jr.

    1974-01-01

    User and programer documentation for the WIDOWAC programs is given. WIDOWAC may be used for the design of minimum mass wing structures subjected to flutter, strength, and minimum gage constraints. The wing structure is modeled by finite elements, flutter conditions may be both subsonic and supersonic, and mathematical programing methods are used for the optimization procedure. The user documentation gives general directions on how the programs may be used and describes their limitations; in addition, program input and output are described, and example problems are presented. A discussion of computational algorithms and flow charts of the WIDOWAC programs and major subroutines is also given.

  12. Theoretical constraints in the design of multivariable control systems

    NASA Technical Reports Server (NTRS)

    Rynaski, E. G.; Mook, D. Joseph; Depena, Juan

    1991-01-01

    The research being performed under NASA Grant NAG1-1361 involves a more clear understanding and definition of the constraints involved in the pole-zero placement or assignment process for multiple input, multiple output systems. Complete state feedback to more than a single controller under conditions of complete controllability and observability is redundant if pole placement alone is the design objective. The additional feedback gains, above and beyond those required for pole placement can be used for eignevalue assignment or zero placement of individual closed loop transfer functions. Because both poles and zeros of individual closed loop transfer functions strongly affect the dynamic response to a pilot command input, the pole-zero placement problem is important. When fewer controllers than degrees of freedom of motion are available, complete design freedom is not possible, the transmission zeros constrain the regions of possible pole-zero placement. The effect of transmission zero constraints on the design possibilities, selection of transmission zeros and the avoidance of producing non-minimum phase transfer functions is the subject of the research being performed under this grant.

  13. Water Infrastructure Adaptation in New Urban Design: Possibilities and Constraints

    EPA Science Inventory

    Natural constraints, including climate change and dynamic socioeconomic development, can significantly impact the way we plan, design, and operate water infrastructure, thus its sustainability to deliver reliable quality water supplies and comply with environmental regulations. ...

  14. Contextual Shaping of Student Design Practices: The Role of Constraint in First-Year Engineering Design

    NASA Astrophysics Data System (ADS)

    Goncher, Andrea M.

    thResearch on engineering design is a core area of concern within engineering education, and a fundamental understanding of how engineering students approach and undertake design is necessary in order to develop effective design models and pedagogies. This dissertation contributes to scholarship on engineering design by addressing a critical, but as yet underexplored, problem: how does the context in which students design shape their design practices? Using a qualitative study comprising of video data of design sessions, focus group interviews with students, and archives of their design work, this research explored how design decisions and actions are shaped by context, specifically the context of higher education. To develop a theoretical explanation for observed behavior, this study used the nested structuration. framework proposed by Perlow, Gittell, & Katz (2004). This framework explicated how teamwork is shaped by mutually reinforcing relationships at the individual, organizational, and institutional levels. I appropriated this framework to look specifically at how engineering students working on a course-related design project identify constraints that guide their design and how these constraints emerge as students interact while working on the project. I first identified and characterized the parameters associated with the design project from the student perspective and then, through multi-case studies of four design teams, I looked at the role these parameters play in student design practices. This qualitative investigation of first-year engineering student design teams revealed mutual and interconnected relationships between students and the organizations and institutions that they are a part of. In addition to contributing to research on engineering design, this work provides guidelines and practices to help design educators develop more effective design projects by incorporating constraints that enable effective design and learning. Moreover, I found

  15. Teaching Database Design with Constraint-Based Tutors

    ERIC Educational Resources Information Center

    Mitrovic, Antonija; Suraweera, Pramuditha

    2016-01-01

    Design tasks are difficult to teach, due to large, unstructured solution spaces, underspecified problems, non-existent problem solving algorithms and stopping criteria. In this paper, we comment on our approach to develop KERMIT, a constraint-based tutor that taught database design. In later work, we re-implemented KERMIT as EER-Tutor, and…

  16. Magnetic design constraints of helical solenoids

    SciTech Connect

    Lopes, M. L.; Krave, S. T.; Tompkins, J. C.; Yonehara, K.; Flanagan, G.; Kahn, S. A.; Melconian, K.

    2015-01-30

    Helical solenoids have been proposed as an option for a Helical Cooling Channel for muons in a proposed Muon Collider. Helical solenoids can provide the required three main field components: solenoidal, helical dipole, and a helical gradient. In general terms, the last two are a function of many geometric parameters: coil aperture, coil radial and longitudinal dimensions, helix period and orbit radius. In this paper, we present design studies of a Helical Solenoid, addressing the geometric tunability limits and auxiliary correction system.

  17. Mars Rover Sample Return aerocapture configuration design and packaging constraints

    NASA Technical Reports Server (NTRS)

    Lawson, Shelby J.

    1989-01-01

    This paper discusses the aerodynamics requirements, volume and mass constraints that lead to a biconic aeroshell vehicle design that protects the Mars Rover Sample Return (MRSR) mission elements from launch to Mars landing. The aerodynamic requirements for Mars aerocapture and entry and packaging constraints for the MRSR elements result in a symmetric biconic aeroshell that develops a L/D of 1.0 at 27.0 deg angle of attack. A significant problem in the study is obtaining a cg that provides adequate aerodynamic stability and performance within the mission imposed constraints. Packaging methods that relieve the cg problems include forward placement of aeroshell propellant tanks and incorporating aeroshell structure as lander structure. The MRSR missions developed during the pre-phase A study are discussed with dimensional and mass data included. Further study is needed for some missions to minimize MRSR element volume so that launch mass constraints can be met.

  18. 77 FR 14592 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-12

    ... Office of Foreign Assets Control Additional Designations, Foreign Narcotics Kingpin Designation Act... whose property and interests in property have ] been blocked pursuant to the Foreign Narcotics Kingpin... the activities of significant foreign narcotics traffickers and their organizations on a...

  19. 77 FR 69707 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-20

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE TREASURY Office of Foreign Assets Control Additional Designations, Foreign Narcotics Kingpin Designation Act... property and interests in property has been blocked pursuant to the Foreign Narcotics Kingpin...

  20. 76 FR 25405 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-04

    ... Office of Foreign Assets Control Additional Designations, Foreign Narcotics Kingpin Designation Act... whose property and interests in property have been blocked pursuant to the Foreign Narcotics Kingpin... the activities of significant foreign narcotics traffickers and their organizations on a...

  1. 78 FR 53007 - Additional Designation, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-27

    ... of the Central Intelligence Agency, the Director of the Federal Bureau of Investigation, the... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE TREASURY Office of Foreign Assets Control Additional Designation, Foreign Narcotics Kingpin Designation Act...

  2. Optimality criteria solution strategies in multiple constraint design optimization

    NASA Technical Reports Server (NTRS)

    Levy, R.; Parzynski, W.

    1981-01-01

    Procedures and solution strategies are described to solve the conventional structural optimization problem using the Lagrange multiplier technique. The multipliers, obtained through solution of an auxiliary nonlinear optimization problem, lead to optimality criteria to determine the design variables. It is shown that this procedure is essentially equivalent to an alternative formulation using a dual method Lagrangian function objective. Although mathematical formulations are straight-forward, successful applications and computational efficiency depend upon execution procedure strategies. Strategies examined, with application examples, include selection of active constraints, move limits, line search procedures, and side constraint boundaries.

  3. Engineering design constraints of the lunar surface environment

    NASA Technical Reports Server (NTRS)

    Morrison, D. A.

    1992-01-01

    Living and working on the lunar surface will be difficult. Design of habitats, machines, tools, and operational scenarios in order to allow maximum flexibility in human activity will require paying attention to certain constraints imposed by conditions at the surface and the characteristics of lunar material. Primary design drivers for habitat, crew health and safety, and crew equipment are: ionizing radiation, the meteoroid flux, and the thermal environment. Secondary constraints for engineering derive from: the physical and chemical properties of lunar surface materials, rock distributions and regolith thicknesses, topography, electromagnetic properties, and seismicity. Protection from ionizing radiation is essential for crew health and safety. The total dose acquired by a crew member will be the sum of the dose acquired during EVA time (when shielding will be least) plus the dose acquired during time spent in the habitat (when shielding will be maximum). Minimizing the dose acquired in the habitat extends the time allowable for EVA's before a dose limit is reached. Habitat shielding is enabling, and higher precision in predicting secondary fluxes produced in shielding material would be desirable. Means for minimizing dose during a solar flare event while on extended EVA will be essential. Early warning of the onset of flare activity (at least a half-hour is feasible) will dictate the time available to take mitigating steps. Warning capability affects design of rovers (or rover tools) and site layout. Uncertainty in solar flare timing is a design constraint that points to the need for quickly accessible or constructible safe havens.

  4. Strict Constraint Feasibility in Analysis and Design of Uncertain Systems

    NASA Technical Reports Server (NTRS)

    Crespo, Luis G.; Giesy, Daniel P.; Kenny, Sean P.

    2006-01-01

    This paper proposes a methodology for the analysis and design optimization of models subject to parametric uncertainty, where hard inequality constraints are present. Hard constraints are those that must be satisfied for all parameter realizations prescribed by the uncertainty model. Emphasis is given to uncertainty models prescribed by norm-bounded perturbations from a nominal parameter value, i.e., hyper-spheres, and by sets of independently bounded uncertain variables, i.e., hyper-rectangles. These models make it possible to consider sets of parameters having comparable as well as dissimilar levels of uncertainty. Two alternative formulations for hyper-rectangular sets are proposed, one based on a transformation of variables and another based on an infinity norm approach. The suite of tools developed enable us to determine if the satisfaction of hard constraints is feasible by identifying critical combinations of uncertain parameters. Since this practice is performed without sampling or partitioning the parameter space, the resulting assessments of robustness are analytically verifiable. Strategies that enable the comparison of the robustness of competing design alternatives, the approximation of the robust design space, and the systematic search for designs with improved robustness characteristics are also proposed. Since the problem formulation is generic and the solution methods only require standard optimization algorithms for their implementation, the tools developed are applicable to a broad range of problems in several disciplines.

  5. Designing under Constraints: Cell Phone Case Design Challenge

    ERIC Educational Resources Information Center

    Sutton, Kevin; Grubbs, Michael E.; Ernst, Jeremy

    2014-01-01

    Engineering design has been suggested as a viable instructional approach for Technology Education (TE) to intentionally provide students the opportunity to apply multidisciplinary concepts to solve ill-defined design challenges (Wells & Ernst, 2012; Sanders & Wells, 2010; Wicklein, 2006). Currently, the context for design challenges in TE…

  6. Minimum weight design of rectangular and tapered helicopter rotor blades with frequency constraints

    NASA Technical Reports Server (NTRS)

    Chattopadhyay, Aditi; Walsh, Joanne L.

    1988-01-01

    The minimum weight design of a helicopter rotor blade subject to constraints on coupled flap-lag natural frequencies has been studied. A constraint has also been imposed on the minimum value of the autorotational inertia of the blade in order to ensure that it has sufficient inertia to autorotate in the case of engine failure. The program CAMRAD is used for the blade modal analysis and CONMIN is used for the optimization. In addition, a linear approximation analysis involving Taylor series expansion has been used to reduce the analysis effort. The procedure contains a sensitivity analysis which consists of analytical derivatives of the objective function and the autorotational inertia constraint and central finite difference derivatives of the frequency constraints. Optimum designs have been obtained for both rectangular and tapered blades. Design variables include taper ratio, segment weights, and box beam dimensions. It is shown that even when starting with an acceptable baseline design, a significant amount of weight reduction is possible while satisfying all the constraints for both rectangular and tapered blades.

  7. Study on singular radius and surface boundary constraint in refractive beam shaper design

    SciTech Connect

    Liu, C.; Zhang, Shukui

    2007-10-01

    Abstract: This paper presents analysis on important issues associated with the design of the refractive laser beam shaping system. The concept of â singular radiusâ is introduced along with solutions to minimize its adverse effect on the shaper performance. In addition, the surface boundary constraint is also discussed in details. This study provides useful guidelines against possible general design errors that would degrade the shaper quality or add undesired complication to the system.

  8. Design constraints on Cherenkov telescopes with Davies-Cotton reflectors

    NASA Astrophysics Data System (ADS)

    Bretz, T.; Ribordy, M.

    2013-05-01

    This paper discusses the construction of high-performance ground-based gamma-ray Cherenkov telescopes with a Davies-Cotton reflector. For the design of such telescopes, usually physics constrains the field-of-view, while the photo-sensor size is defined by limited options. Including the effect of light-concentrators, it is demonstrated that these constraints are enough to mutually constrain all other design parameters. The dependability of the various design parameters naturally arises once a relationship between the value of the point-spread functions at the edge of the field-of-view and the pixel field-of-view is introduced. To be able to include this constraint into a system of equations, an analytical description for the point-spread function of a tessellated Davies-Cotton reflector is derived from Taylor developments and ray-tracing simulations. Including higher order terms renders the result precise on the percent level. Design curves are provided within the typical phase space of Cherenkov telescopes. The impact of all design parameters on the overall design is discussed. Allowing an immediate comparison of several options with identical physics performance allows the determination of the most cost efficient solution. Emphasis is given on the possible application of solid light concentrators with their typically about two times better concentration compared with hollow cones which allows the use of small photo sensors such as Geiger-mode avalanche photo diodes. This is discussed in more details in the context of possible design options for the Cherenkov Telescope Array. In particular, a solution for a 60 mm2 photo sensor with hollow cone is compared to a 36 mm2 with solid cone.

  9. Design constraints of the LST fine guidance sensor

    NASA Technical Reports Server (NTRS)

    Wissinger, A. B.

    1975-01-01

    The LST Fine Guidance Sensor design is shaped by the rate of occurrence of suitable guide stars, the competition for telescope focal plane space with the Science Instruments, and the sensitivity of candidate image motion sensors. The relationship between these parameters is presented, and sensitivity to faint stars is shown to be of prime importance. An interferometric technique of image motion sensing is shown to have improved sensitivity and, therefore, a reduced focal plane area requirement in comparison with other candidate techniques (image-splitting prism and image dissector tube techniques). Another design requirement is speed in acquiring the guide star in order to maximize the time available for science observations. The design constraints are shown parametrically, and modelling results are presented.

  10. Design and additive manufacture for flow chemistry.

    PubMed

    Capel, Andrew J; Edmondson, Steve; Christie, Steven D R; Goodridge, Ruth D; Bibb, Richard J; Thurstans, Matthew

    2013-12-01

    We review the use of additive manufacturing (AM) as a novel manufacturing technique for the production of milli-scale reactor systems. Five well-developed additive manufacturing techniques: stereolithography (SL), multi-jet modelling (MJM), selective laser melting (SLM), laser sintering (LS) and fused deposition modelling (FDM) were used to manufacture a number of miniaturised reactors which were tested using a range of organic and inorganic reactions. PMID:24100659

  11. Motorcycle suspension design using matrix inequalities and passivity constraints

    NASA Astrophysics Data System (ADS)

    Sharma, Amrit; Limebeer, David J. N.

    2012-03-01

    This paper presents a design methodology for the suspension system of a novel aerodynamically efficient motorcycle. Since the machine's layout and the rider's seating position are unconventional, several aspects of the machine design, including the suspension, must be reviewed afresh. The design process is based on matrix inequalities that are used to optimise a road-grip objective function - others could be used equally well. The design problem is cast as the minimisation of an H 2 cost with passivity constraints imposed on the suspension transference. The resulting bilinear matrix inequality problem is solved using a locally optimal iterative algorithm. The matrix inequality-type characterisation of positive real functions permits the optimisation of the suspension system over an entire class of passive admittances. Torsional springs, dampers and inerters are then used to construct networks corresponding to the optimal (positive real) admittances. Networks of first, second, third and fourth orders are considered, and an argument based on the compromise between complexity and improved grip is made for the most suitable suspension configuration. Finally, the effects of improved road grip on the stability of the vehicle's lateral dynamics are analysed.

  12. Accelerated Source-Encoding Full-Waveform Inversion with Additional Constraints

    NASA Astrophysics Data System (ADS)

    Boehm, C.; Fichtner, A.; Ulbrich, M.

    2014-12-01

    We present a flexible framework of Newton-type methods for constrained full-waveform inversion in the time domain. Our main goal is (1) to incorporate additional prior knowledge by using general constraints on the model parameters and (2) to reduce the computational costs of solving the inverse problem by tailoring source-encoding strategies to Newton-type methods.In particular, we apply the Moreau-Yosida regularization to handle the constraints and use a continuation strategy to adjust the regularization parameter. Furthermore, we propose a semismooth Newton method with a trust-region globalization that relies on second-order adjoints to compute the Newton system with a matrix-free preconditioned conjugate gradient solver. The costs of conventional FWI approaches scale proportionally with the number of seismic sources. Here, source-encoding strategies that trigger different sources simultaneously have been proven to be a successful tool to trade a small loss of information for huge savings of computational time to solve the inverse problem. This is particularly interesting for our setting as one iteration of Newton's methods using the full Hessian is considerably more expensive than quasi-Newton methods like L-BFGS. To this end, we discuss a sample average approximation model that is accelerated by using inexact Hessian information based on mini-batches of the samples. Furthermore, we compare its performance with stochastic descent schemes. Here, the classical stochastic gradient method is accelerated by an L-BFGS preconditioner and moreover, the stability of this stochastic preconditioner is enhanced by using the Hessian instead of only gradient information.Numerical results are presented for problems in geophysical exploration on reservoir-scale.

  13. Can an energy balance model provide additional constraints on how to close the energy imbalance?

    PubMed Central

    Wohlfahrt, Georg; Widmoser, Peter

    2013-01-01

    Elucidating the causes for the energy imbalance, i.e. the phenomenon that eddy covariance latent and sensible heat fluxes fall short of available energy, is an outstanding problem in micrometeorology. This paper tests the hypothesis that the full energy balance, through incorporation of additional independent measurements which determine the driving forces of and resistances to energy transfer, provides further insights into the causes of the energy imbalance and additional constraints on energy balance closure options. Eddy covariance and auxiliary data from three different biomes were used to test five contrasting closure scenarios. The main result of our study is that except for nighttime, when fluxes were low and noisy, the full energy balance generally did not contain enough information to allow further insights into the causes of the imbalance and to constrain energy balance closure options. Up to four out of the five tested closure scenarios performed similarly and in up to 53% of all cases all of the tested closure scenarios resulted in plausible energy balance values. Our approach may though provide a sensible consistency check for eddy covariance energy flux measurements. PMID:24465072

  14. Can an energy balance model provide additional constraints on how to close the energy imbalance?

    PubMed

    Wohlfahrt, Georg; Widmoser, Peter

    2013-02-15

    Elucidating the causes for the energy imbalance, i.e. the phenomenon that eddy covariance latent and sensible heat fluxes fall short of available energy, is an outstanding problem in micrometeorology. This paper tests the hypothesis that the full energy balance, through incorporation of additional independent measurements which determine the driving forces of and resistances to energy transfer, provides further insights into the causes of the energy imbalance and additional constraints on energy balance closure options. Eddy covariance and auxiliary data from three different biomes were used to test five contrasting closure scenarios. The main result of our study is that except for nighttime, when fluxes were low and noisy, the full energy balance generally did not contain enough information to allow further insights into the causes of the imbalance and to constrain energy balance closure options. Up to four out of the five tested closure scenarios performed similarly and in up to 53% of all cases all of the tested closure scenarios resulted in plausible energy balance values. Our approach may though provide a sensible consistency check for eddy covariance energy flux measurements.

  15. Integrated reservoir characterization: Improvement in heterogeneities stochastic modelling by integration of additional external constraints

    SciTech Connect

    Doligez, B.; Eschard, R.; Geffroy, F.

    1997-08-01

    The classical approach to construct reservoir models is to start with a fine scale geological model which is informed with petrophysical properties. Then scaling-up techniques allow to obtain a reservoir model which is compatible with the fluid flow simulators. Geostatistical modelling techniques are widely used to build the geological models before scaling-up. These methods provide equiprobable images of the area under investigation, which honor the well data, and which variability is the same than the variability computed from the data. At an appraisal phase, when few data are available, or when the wells are insufficient to describe all the heterogeneities and the behavior of the field, additional constraints are needed to obtain a more realistic geological model. For example, seismic data or stratigraphic models can provide average reservoir information with an excellent areal coverage, but with a poor vertical resolution. New advances in modelisation techniques allow now to integrate this type of additional external information in order to constrain the simulations. In particular, 2D or 3D seismic derived information grids, or sand-shale ratios maps coming from stratigraphic models can be used as external drifts to compute the geological image of the reservoir at the fine scale. Examples are presented to illustrate the use of these new tools, their impact on the final reservoir model, and their sensitivity to some key parameters.

  16. An identification method for enclosed voids restriction in manufacturability design for additive manufacturing structures

    NASA Astrophysics Data System (ADS)

    Liu, Shutian; Li, Quhao; Chen, Wenjiong; Tong, Liyong; Cheng, Gengdong

    2015-06-01

    Additive manufacturing (AM) technologies, such as selective laser sintering (SLS) and fused deposition modeling (FDM), have become the powerful tools for direct manufacturing of complex parts. This breakthrough in manufacturing technology makes the fabrication of new geometrical features and multiple materials possible. Past researches on designs and design methods often focused on how to obtain desired functional performance of the structures or parts, specific manufacturing capabilities as well as manufacturing constraints of AM were neglected. However, the inherent constraints in AM processes should be taken into account in design process. In this paper, the enclosed voids, one type of manufacturing constraints of AM, are investigated. In mathematics, enclosed voids restriction expressed as the solid structure is simplyconnected. We propose an equivalent description of simply-connected constraint for avoiding enclosed voids in structures, named as virtual temperature method (VTM). In this method, suppose that the voids in structure are filled with a virtual heating material with high heat conductivity and solid areas are filled with another virtual material with low heat conductivity. Once the enclosed voids exist in structure, the maximum temperature value of structure will be very high. Based upon this method, the simplyconnected constraint is equivalent to maximum temperature constraint. And this method can be easily used to formulate the simply-connected constraint in topology optimization. The effectiveness of this description method is illustrated by several examples. Based upon topology optimization, an example of 3D cantilever beam is used to illustrate the trade-off between manufacturability and functionality. Moreover, the three optimized structures are fabricated by FDM technology to indicate further the necessity of considering the simply-connected constraint in design phase for AM.

  17. Dynamic Financial Constraints: Distinguishing Mechanism Design from Exogenously Incomplete Regimes.

    PubMed

    Karaivanov, Alexander; Townsend, Robert M

    2014-05-01

    We formulate and solve a range of dynamic models of constrained credit/insurance that allow for moral hazard and limited commitment. We compare them to full insurance and exogenously incomplete financial regimes (autarky, saving only, borrowing and lending in a single asset). We develop computational methods based on mechanism design, linear programming, and maximum likelihood to estimate, compare, and statistically test these alternative dynamic models with financial/information constraints. Our methods can use both cross-sectional and panel data and allow for measurement error and unobserved heterogeneity. We estimate the models using data on Thai households running small businesses from two separate samples. We find that in the rural sample, the exogenously incomplete saving only and borrowing regimes provide the best fit using data on consumption, business assets, investment, and income. Family and other networks help consumption smoothing there, as in a moral hazard constrained regime. In contrast, in urban areas, we find mechanism design financial/information regimes that are decidedly less constrained, with the moral hazard model fitting best combined business and consumption data. We perform numerous robustness checks in both the Thai data and in Monte Carlo simulations and compare our maximum likelihood criterion with results from other metrics and data not used in the estimation. A prototypical counterfactual policy evaluation exercise using the estimation results is also featured.

  18. Dynamic Financial Constraints: Distinguishing Mechanism Design from Exogenously Incomplete Regimes.

    PubMed

    Karaivanov, Alexander; Townsend, Robert M

    2014-05-01

    We formulate and solve a range of dynamic models of constrained credit/insurance that allow for moral hazard and limited commitment. We compare them to full insurance and exogenously incomplete financial regimes (autarky, saving only, borrowing and lending in a single asset). We develop computational methods based on mechanism design, linear programming, and maximum likelihood to estimate, compare, and statistically test these alternative dynamic models with financial/information constraints. Our methods can use both cross-sectional and panel data and allow for measurement error and unobserved heterogeneity. We estimate the models using data on Thai households running small businesses from two separate samples. We find that in the rural sample, the exogenously incomplete saving only and borrowing regimes provide the best fit using data on consumption, business assets, investment, and income. Family and other networks help consumption smoothing there, as in a moral hazard constrained regime. In contrast, in urban areas, we find mechanism design financial/information regimes that are decidedly less constrained, with the moral hazard model fitting best combined business and consumption data. We perform numerous robustness checks in both the Thai data and in Monte Carlo simulations and compare our maximum likelihood criterion with results from other metrics and data not used in the estimation. A prototypical counterfactual policy evaluation exercise using the estimation results is also featured. PMID:25246710

  19. Dynamic Financial Constraints: Distinguishing Mechanism Design from Exogenously Incomplete Regimes*

    PubMed Central

    Karaivanov, Alexander; Townsend, Robert M.

    2014-01-01

    We formulate and solve a range of dynamic models of constrained credit/insurance that allow for moral hazard and limited commitment. We compare them to full insurance and exogenously incomplete financial regimes (autarky, saving only, borrowing and lending in a single asset). We develop computational methods based on mechanism design, linear programming, and maximum likelihood to estimate, compare, and statistically test these alternative dynamic models with financial/information constraints. Our methods can use both cross-sectional and panel data and allow for measurement error and unobserved heterogeneity. We estimate the models using data on Thai households running small businesses from two separate samples. We find that in the rural sample, the exogenously incomplete saving only and borrowing regimes provide the best fit using data on consumption, business assets, investment, and income. Family and other networks help consumption smoothing there, as in a moral hazard constrained regime. In contrast, in urban areas, we find mechanism design financial/information regimes that are decidedly less constrained, with the moral hazard model fitting best combined business and consumption data. We perform numerous robustness checks in both the Thai data and in Monte Carlo simulations and compare our maximum likelihood criterion with results from other metrics and data not used in the estimation. A prototypical counterfactual policy evaluation exercise using the estimation results is also featured. PMID:25246710

  20. Stakeholders' influence on the importance of users' and clients' information and constraints during website design.

    PubMed

    Chevalier, Aline

    2007-12-01

    The present study aims at determining the role of the stakeholder (via a user vs a client spokesperson) on the importance allocated to information and constraints considered by novice and professional web designers. Analysis showed all designers focused mainly on clients' constraints and information even when they dealt with a user spokesperson: they considered clients' constraints as more important than users' constraints. These results are new with regard to those previously obtained in web design, which showed designers considered prescribed constraints (regardless of the stakeholder to which they are related) as unavaoidable, and the vast majority of others as avoidable if required. Research is required to help web designers to ponder users' and clients' constraints and to assess whether the same patterns of results occur in other design domains. PMID:18232453

  1. 14 CFR 13.107 - Designation of additional parties.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Designation of additional parties. 13.107... Investigation § 13.107 Designation of additional parties. (a) The Presiding Officer may designate additional persons as parties to the investigation, if in the discretion of the Presiding Officer, it will aid in...

  2. Modified Fully Utilized Design (MFUD) Method for Stress and Displacement Constraints

    NASA Technical Reports Server (NTRS)

    Patnaik, Surya; Gendy, Atef; Berke, Laszlo; Hopkins, Dale

    1997-01-01

    The traditional fully stressed method performs satisfactorily for stress-limited structural design. When this method is extended to include displacement limitations in addition to stress constraints, it is known as the fully utilized design (FUD). Typically, the FUD produces an overdesign, which is the primary limitation of this otherwise elegant method. We have modified FUD in an attempt to alleviate the limitation. This new method, called the modified fully utilized design (MFUD) method, has been tested successfully on a number of designs that were subjected to multiple loads and had both stress and displacement constraints. The solutions obtained with MFUD compare favorably with the optimum results that can be generated by using nonlinear mathematical programming techniques. The MFUD method appears to have alleviated the overdesign condition and offers the simplicity of a direct, fully stressed type of design method that is distinctly different from optimization and optimality criteria formulations. The MFUD method is being developed for practicing engineers who favor traditional design methods rather than methods based on advanced calculus and nonlinear mathematical programming techniques. The Integrated Force Method (IFM) was found to be the appropriate analysis tool in the development of the MFUD method. In this paper, the MFUD method and its optimality are presented along with a number of illustrative examples.

  3. 76 FR 58562 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-21

    ... the Attorney General, the Director of the Central Intelligence Agency, the Director of the Federal... Designation Act AGENCY: Office of Foreign Assets Control, Treasury. ACTION: Notice. SUMMARY: The...

  4. Additional Constraints on the Shallow Seismic Velocity Structure of the Atlantis Massif Oceanic Core Complex

    NASA Astrophysics Data System (ADS)

    Henig, A. S.; Blackman, D. K.; Harding, A. J.; Kent, G. M.; Canales, J. P.

    2008-12-01

    We investigate the detailed structure of the uppermost ~km of Atlantis Massif, an oceanic core complex at 30°N on the Mid Atlantic Ridge, using pre-existing multichannel seismic data. The Synthetic On- Bottom Experiment (SOBE) method that we employ downward continues both the shots and receivers to a depth just above the seafloor. This allows us to pick refracted arrivals recorded on the streamer at very-near offset, providing constraints from rays that are received within the 300-2000 m range that was unavailable to earlier studies where standard shot gathers had been analyzed. Thus, we can better model the upper few hundred meters of the section which, in turn, adds confidence for determining the deeper (400-1500 m) structure. New work on a ridge-parallel line has been added to last year's work on a cross-axis line over the Central Dome of the massif. Tomographic results are similar for these crossing lines: a thin (100-150 m) low velocity (< 3 km/s) layer caps the dome; high horizontal gradients (>1.25 s-1) occur in local (1-2 km wide) regions within these 6-8 km long subsections of the MCS lines analyzed to date; and very high vertical velocity gradients, greater than 3.75 s-1, occur within the km just below the exposed detachment in these areas. We obtain general agreement with Canales et al., 2008, results over the Central Dome but our models suggest a finer scale lateral heterogeneity. We have begun analysis of additional and extended MCS lines over the domal core of the massif and our priority for this presentation is to assess the detailed structure of the Southern Ridge. In at least some areas the thin, low velocity layer contrasts sufficiently with underlying material that a clear refracted arrival is visible in supergathers. We will determine whether the low velocity layer persists over the whole dome or if it is restricted to the Central Dome. An important question is whether its thickness on the Southern Ridge, if it exists there, differs from that

  5. DETAIL OF PLAQUE WITH ADDITIONAL DESIGN AND CONSTRUCTION INFORMATION, SOUTHEAST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF PLAQUE WITH ADDITIONAL DESIGN AND CONSTRUCTION INFORMATION, SOUTHEAST ABUTMENT - Connecticut Avenue Bridge, Spans Rock Creek & Potomac Parkway at Connecticut Avenue, Washington, District of Columbia, DC

  6. Laser Additive Manufacturing and Bionics: Redefining Lightweight Design

    NASA Astrophysics Data System (ADS)

    Emmelmann, C.; Sander, P.; Kranz, J.; Wycisk, E.

    New layer wise manufacturing technologies such as Laser Additive Manufacturing (LAM) allow innovative approaches to product design. Especially for lightweight design in aircraft applications LAM offers new possibilities for load-adapted structures. However, to fully capture lightweight potential of LAM technologies new design guidelines and processes have to be developed. A novel approach to extreme lightweight design is realized by incorporating structural optimization tools, bionic structures and LAM guidelines into one design process. By consequently following this design process designers can achieve lightweight savings in designing new aircraft structures.

  7. Battery-package design provides for cell cooling and constraint

    NASA Technical Reports Server (NTRS)

    Gross, S.

    1968-01-01

    Lightweight battery-package provides for even cooling of individual alkaline cells, constraint against cell expansion, and convenient placement of cells. The battery package also provides for venting of the cells and includes instrumentation to measure cell temperature, pressure, and voltage.

  8. A flexible computer aid for conceptual design based on constraint propagation and component-modeling. [of aircraft in three dimensions

    NASA Technical Reports Server (NTRS)

    Kolb, Mark A.

    1988-01-01

    The Rubber Airplane program, which combines two symbolic processing techniques with a component-based database of design knowledge, is proposed as a computer aid for conceptual design. Using object-oriented programming, programs are organized around the objects and behavior to be simulated, and using constraint propagation, declarative statements designate mathematical relationships among all the equation variables. It is found that the additional level of organizational structure resulting from the arrangement of the design information in terms of design components provides greater flexibility and convenience.

  9. Contextual constraints for the design of patient-centered health IT tools.

    PubMed

    Gonzales, Michael J; O'Connor, Maria Francesca; Riek, Laurel D

    2013-01-01

    Technologists are constantly working to improve clinical practice by developing new health information technology (Health IT) tools, yet may not always consider the context of how these tools may be used. Patient preferences can vary widely as a result of demographics, health conditions, physical limitations, and personal inclinations, with healthcare providers having to adapt clinical encounters to better suit patient needs. Health IT tools, too, need to be agile across different healthcare contexts, with each stakeholder's specific needs in mind. In this paper, we discuss the challenges and limitations associated with the design and automation of contextually sensitive devices in the healthcare environment. We target the various contexts in which health information is presented in patient-provider encounters, and discuss contextual constraints that may apply to the aforementioned situations. In addition, we present a number of suggestions for informational constraints and the design of informational tools in these settings so that patient and provider informational needs can be better met in clinical communication contexts.

  10. The design of impact absorbing structures for additive manufacture

    NASA Astrophysics Data System (ADS)

    Brennan-Craddock, J.; Brackett, D.; Wildman, R.; Hague, R.

    2012-08-01

    Additive manufacturing (AM) is increasingly becoming a viable manufacturing process due to dramatic advantages that it facilitates in the area of design complexity. This paper investigates the potential of additively manufactured lattice structures for the application of tailored impact absorption specifically for conformal body protection. It explores lattice cell types based on foam microstructures and assesses their suitability for impact absorption. The effect of varying the cell strut edge design is also investigated. The implications of scaling these cells up for AM are discussed as well as the design issues regarding the handling of geometric complexity and the requirement for body conformity. The suitability of AM materials for this application is also discussed.

  11. A methodology for designing aircraft to low sonic boom constraints

    NASA Technical Reports Server (NTRS)

    Mack, Robert J.; Needleman, Kathy E.

    1991-01-01

    A method for designing conceptual supersonic cruise aircraft to meet low sonic boom requirements is outlined and described. The aircraft design is guided through a systematic evolution from initial three view drawing to a final numerical model description, while the designer using the method controls the integration of low sonic boom, high supersonic aerodynamic efficiency, adequate low speed handling, and reasonable structure and materials technologies. Some experience in preliminary aircraft design and in the use of various analytical and numerical codes is required for integrating the volume and lift requirements throughout the design process.

  12. Just-in-time Design and Additive Manufacture of Patient-specific Medical Implants

    NASA Astrophysics Data System (ADS)

    Shidid, Darpan; Leary, Martin; Choong, Peter; Brandt, Milan

    Recent advances in medical imaging and manufacturing science have enabled the design and production of complex, patient-specific orthopaedic implants. Additive Manufacture (AM) generates three-dimensional structures layer by layer, and is not subject to the constraints associated with traditional manufacturing methods. AM provides significant opportunities for the design of novel geometries and complex lattice structures with enhanced functional performance. However, the design and manufacture of patient-specific AM implant structures requires unique expertise in handling various optimization platforms. Furthermore, the design process for complex structures is computationally intensive. The primary aim of this research is to enable the just-in-time customisation of AM prosthesis; whereby AM implant design and manufacture be completed within the time constraints of a single surgical procedure, while minimising prosthesis mass and optimising the lattice structure to match the stiffness of the surrounding bone tissue. In this research, a design approach using raw CT scan data is applied to the AM manufacture of femoral prosthesis. Using the proposed just-in-time concept, the mass of the prosthesis was rapidly designed and manufactured while satisfying the associated structural requirements. Compressive testing of lattice structures manufactured using proposed method shows that the load carrying capacity of the resected composite bone can be recovered by up to 85% and the compressive stiffness of the AM prosthesis is statistically indistinguishable from the stiffness of the initial bone.

  13. Additivity in the Analysis and Design of HIV Protease Inhibitors

    PubMed Central

    Jorissen, Robert N.; Kiran Kumar Reddy, G. S.; Ali, Akbar; Altman, Michael D.; Chellappan, Sripriya; Anjum, Saima G.; Tidor, Bruce; Schiffer, Celia A.; Rana, Tariq M.; Gilson, Michael K.

    2009-01-01

    We explore the applicability of an additive treatment of substituent effects to the analysis and design of HIV protease inhibitors. Affinity data for a set of inhibitors with a common chemical framework were analyzed to provide estimates of the free energy contribution of each chemical substituent. These estimates were then used to design new inhibitors, whose high affinities were confirmed by synthesis and experimental testing. Derivations of additive models by least-squares and ridge-regression methods were found to yield statistically similar results. The additivity approach was also compared with standard molecular descriptor-based QSAR; the latter was not found to provide superior predictions. Crystallographic studies of HIV protease-inhibitor complexes help explain the perhaps surprisingly high degree of substituent additivity in this system, and allow some of the additivity coefficients to be rationalized on a structural basis. PMID:19193159

  14. An investigation of constraint-based component-modeling for knowledge representation in computer-aided conceptual design

    NASA Technical Reports Server (NTRS)

    Kolb, Mark A.

    1990-01-01

    Originally, computer programs for engineering design focused on detailed geometric design. Later, computer programs for algorithmically performing the preliminary design of specific well-defined classes of objects became commonplace. However, due to the need for extreme flexibility, it appears unlikely that conventional programming techniques will prove fruitful in developing computer aids for engineering conceptual design. The use of symbolic processing techniques, such as object-oriented programming and constraint propagation, facilitate such flexibility. Object-oriented programming allows programs to be organized around the objects and behavior to be simulated, rather than around fixed sequences of function- and subroutine-calls. Constraint propagation allows declarative statements to be understood as designating multi-directional mathematical relationships among all the variables of an equation, rather than as unidirectional assignments to the variable on the left-hand side of the equation, as in conventional computer programs. The research has concentrated on applying these two techniques to the development of a general-purpose computer aid for engineering conceptual design. Object-oriented programming techniques are utilized to implement a user-extensible database of design components. The mathematical relationships which model both geometry and physics of these components are managed via constraint propagation. In addition, to this component-based hierarchy, special-purpose data structures are provided for describing component interactions and supporting state-dependent parameters. In order to investigate the utility of this approach, a number of sample design problems from the field of aerospace engineering were implemented using the prototype design tool, Rubber Airplane. The additional level of organizational structure obtained by representing design knowledge in terms of components is observed to provide greater convenience to the program user, and to

  15. Hyperbolic tangential function-based progressive addition lens design.

    PubMed

    Qiu, Gufeng; Cui, Xudong

    2015-12-10

    The diopter distribution is key to the successful design of a progressive addition lens. A hyperbolic tangential function is then introduced to describe well the desired diopter distribution on the lens. Simulation and fabrication show that the astigmia on the whole surface is very close to the addition, exhibiting superior performance than that of currently used high-order polynomials and cosine functions. Our investigations found that once the diopter distribution design is reasonable, both the direct and indirect methods of constructing a progressive addition lens can give consistent results. With this function we are able to effectively control the design of critical areas, the position, sizes of far-view and near-view zones, as well as the channel of the lens. This study would provide an efficient way to customize different progressive lenses not only for presbyopia, but also for anti-fatigue, office progressive usages, etc. PMID:26836863

  16. Crystallization Experiments of the Martian Meteorite QUE94201: Additional Constraints on Its Formation Condition

    NASA Technical Reports Server (NTRS)

    Koizumi, E.; McKay, G.; Mikouchi, T.; Le, L.; Schwandt, C.; Monkawa, A.; Miyamoto, M.

    2002-01-01

    We focused on the Al/Ti ratio in synthetic pyroxenes as a marker for the onset of plagioclase crystallization and discuss the effects of oxygen fugacity on the Kd(Fe/Mg)ol/gl in our experiments using the same composition of QUE94201. Additional information is contained in the original extended abstract.

  17. The Disciplinary Constraints of SLA and TESOL: Additive Bilingualism and Second Language Acquisition, Teaching and Learning

    ERIC Educational Resources Information Center

    May, Stephen

    2011-01-01

    For over 15 years now, various commentators have highlighted the 'monolingual bias' inherent in SLA and TESOL research, which invariably constructs bi/multilingualism in deficit terms. In contrast, these critics have advocated an additive bilingual approach to SLA and TESOL, albeit, not as yet to any great effect. In this paper, I explore why so…

  18. Engineering Effort Needed to Design Spacecraft with Radiation Constraints

    NASA Technical Reports Server (NTRS)

    Singleterry, Robert C., Jr.

    2005-01-01

    A roadmap is articulated that describes what is needed to allow designers, to include researchers, management, and engineers, to investigate, design, build, test, and fly spacecraft that meet the mission requirements yet, be as low cost as possible. This roadmap describes seven levels of tool fidelity and application: 1) Mission Speculation, 2) Management Overview, 3) Mission Design, 4) Detailed Design, 5) Simulation and Training, 6) Operations, and 7) Research. The interfaces and output are described in top-level detail along with the transport engines needed, and deficiencies are noted. This roadmap, if implemented, will allow Multidisciplinary Optimization (MDO) ideas to incorporate radiation concerns. Also, as NASA moves towards Simulation Based Acquisition (SBA), these tools will facilitate the appropriate spending of government money. Most of the tools needed to serve these levels do not exist or exist in pieces and need to be integrated to create the tool.

  19. Additive Manufacturing Design Considerations for Liquid Engine Components

    NASA Technical Reports Server (NTRS)

    Whitten, Dave; Hissam, Andy; Baker, Kevin; Rice, Darron

    2014-01-01

    The Marshall Space Flight Center's Propulsion Systems Department has gained significant experience in the last year designing, building, and testing liquid engine components using additive manufacturing. The department has developed valve, duct, turbo-machinery, and combustion device components using this technology. Many valuable lessons were learned during this process. These lessons will be the focus of this presentation. We will present criteria for selecting part candidates for additive manufacturing. Some part characteristics are 'tailor made' for this process. Selecting the right parts for the process is the first step to maximizing productivity gains. We will also present specific lessons we learned about feature geometry that can and cannot be produced using additive manufacturing machines. Most liquid engine components were made using a two-step process. The base part was made using additive manufacturing and then traditional machining processes were used to produce the final part. The presentation will describe design accommodations needed to make the base part and lessons we learned about which features could be built directly and which require the final machine process. Tolerance capabilities, surface finish, and material thickness allowances will also be covered. Additive Manufacturing can produce internal passages that cannot be made using traditional approaches. It can also eliminate a significant amount of manpower by reducing part count and leveraging model-based design and analysis techniques. Information will be shared about performance enhancements and design efficiencies we experienced for certain categories of engine parts.

  20. Web-based software tool for constraint-based design specification of synthetic biological systems.

    PubMed

    Oberortner, Ernst; Densmore, Douglas

    2015-06-19

    miniEugene provides computational support for solving combinatorial design problems, enabling users to specify and enumerate designs for novel biological systems based on sets of biological constraints. This technical note presents a brief tutorial for biologists and software engineers in the field of synthetic biology on how to use miniEugene. After reading this technical note, users should know which biological constraints are available in miniEugene, understand the syntax and semantics of these constraints, and be able to follow a step-by-step guide to specify the design of a classical synthetic biological system-the genetic toggle switch.1 We also provide links and references to more information on the miniEugene web application and the integration of the miniEugene software library into sophisticated Computer-Aided Design (CAD) tools for synthetic biology ( www.eugenecad.org ).

  1. A mathematical formulation for interface-based modular product design with geometric and weight constraints

    NASA Astrophysics Data System (ADS)

    Jung-Woon Yoo, John

    2016-06-01

    Since customer preferences change rapidly, there is a need for design processes with shorter product development cycles. Modularization plays a key role in achieving mass customization, which is crucial in today's competitive global market environments. Standardized interfaces among modularized parts have facilitated computational product design. To incorporate product size and weight constraints during computational design procedures, a mixed integer programming formulation is presented in this article. Product size and weight are two of the most important design parameters, as evidenced by recent smart-phone products. This article focuses on the integration of geometric, weight and interface constraints into the proposed mathematical formulation. The formulation generates the optimal selection of components for a target product, which satisfies geometric, weight and interface constraints. The formulation is verified through a case study and experiments are performed to demonstrate the performance of the formulation.

  2. Web-based software tool for constraint-based design specification of synthetic biological systems.

    PubMed

    Oberortner, Ernst; Densmore, Douglas

    2015-06-19

    miniEugene provides computational support for solving combinatorial design problems, enabling users to specify and enumerate designs for novel biological systems based on sets of biological constraints. This technical note presents a brief tutorial for biologists and software engineers in the field of synthetic biology on how to use miniEugene. After reading this technical note, users should know which biological constraints are available in miniEugene, understand the syntax and semantics of these constraints, and be able to follow a step-by-step guide to specify the design of a classical synthetic biological system-the genetic toggle switch.1 We also provide links and references to more information on the miniEugene web application and the integration of the miniEugene software library into sophisticated Computer-Aided Design (CAD) tools for synthetic biology ( www.eugenecad.org ). PMID:25426642

  3. Effect of leading-edge load constraints on the design and performance of supersonic wings

    NASA Technical Reports Server (NTRS)

    Darden, C. M.

    1985-01-01

    A theoretical and experimental investigation was conducted to assess the effect of leading-edge load constraints on supersonic wing design and performance. In the effort to delay flow separation and the formation of leading-edge vortices, two constrained, linear-theory optimization approaches were used to limit the loadings on the leading edge of a variable-sweep planform design. Experimental force and moment tests were made on two constrained camber wings, a flat uncambered wing, and an optimum design with no constraints. Results indicate that vortex strength and separation regions were mildest on the severely and moderately constrained wings.

  4. DESAP 2: A structural design program with stress and buckling constraints. Volume 1: Theoretical and user's manual

    NASA Technical Reports Server (NTRS)

    Kiusalaas, J.; Reddy, G. B.

    1977-01-01

    DESAP 2 is described as a finite element program for computer-automated, minimum weight design of elastic structures with constraints on stresses (including local instability criteria) and buckling loads. No limits are placed on the number of load conditions for stress-constrained design, but only one of these load conditions can be chosen as the potential buckling load. A substantial portion of DESAP 2, particularly the analysis of the prebuckling state, is derived from the SOLID SAP finite element program. The stress-constrained design is based on the classical stress ratio method, which drives the design towards a fully stressed state. The constraints on the buckling load are handled by solving the appropriate optimality criterion by successive iterations. During each iteration, the element sizes determined by the stress ratio method are used as the minimum size constraints. The element subroutines are organized in a manner that permits the user to make additions and changes with a minimal programming effort. Consequently, DESAP 2 can readily be changed into a special-purpose program to handle the user's specific design requirements and failure criteria.

  5. A Modular Aerospike Engine Design Using Additive Manufacturing

    NASA Technical Reports Server (NTRS)

    Peugeot, John; Garcia, Chance; Burkhardt, Wendel

    2014-01-01

    A modular aerospike engine concept has been developed with the objective of demonstrating the viability of the aerospike design using additive manufacturing techniques. The aerospike system is a self-compensating design that allows for optimal performance over the entire flight regime and allows for the lowest possible mass vehicle designs. At low altitudes, improvements in Isp can be traded against chamber pressure, staging, and payload. In upper stage applications, expansion ratio and engine envelope can be traded against nozzle efficiency. These features provide flexibility to the System Designer optimizing a complete vehicle stage. The aerospike concept is a good example of a component that has demonstrated improved performance capability, but traditionally has manufacturing requirements that are too expensive and complex to use in a production vehicle. In recent years, additive manufacturing has emerged as a potential method for improving the speed and cost of building geometrically complex components in rocket engines. It offers a reduction in tooling overhead and significant improvements in the integration of the designer and manufacturing method. In addition, the modularity of the engine design provides the ability to perform full scale testing on the combustion devices outside of the full engine configuration. The proposed design uses a hydrocarbon based gas-generator cycle, with plans to take advantage of existing powerhead hardware while focusing DDT&E resources on manufacturing and sub-system testing of the combustion devices. The major risks for the modular aerospike concept lie in the performance of the propellant feed system, the structural integrity of the additive manufactured components, and the aerodynamic efficiency of the exhaust flow.

  6. Control law design to meet constraints using SYNPAC-synthesis package for active controls

    NASA Technical Reports Server (NTRS)

    Adams, W. M., Jr.; Tiffany, S. H.

    1982-01-01

    Major features of SYNPAC (Synthesis Package for Active Controls) are described. SYNPAC employs constrained optimization techniques which allow explicit inclusion of design criteria (constraints) in the control law design process. Interrelationships are indicated between this constrained optimization approach, classical and linear quadratic Gaussian design techniques. Results are presented that were obtained by applying SYNPAC to the design of a combined stability augmentation/gust load alleviation control law for the DAST ARW-2.

  7. Parametric study of critical constraints for a canard configured medium range transport using conceptual design optimization

    NASA Technical Reports Server (NTRS)

    Arbuckle, P. D.; Sliwa, S. M.

    1983-01-01

    Constrained parameter optimization was used to perform optimal conceptual design of both canard and conventional configurations of a medium range transport. A number of design constants and design constraints were systematically varied to compare the sensitivities of canard and conventional configurations to a variety of technology assumptions. Main landing gear location and horizontal stabilizer high-lift performance were identified as critical design parameters for a statically stable, subsonic canard transport.

  8. Rubber airplane: Constraint-based component-modeling for knowledge representation in computer-aided conceptual design

    NASA Technical Reports Server (NTRS)

    Kolb, Mark A.

    1990-01-01

    Viewgraphs on Rubber Airplane: Constraint-based Component-Modeling for Knowledge Representation in Computer Aided Conceptual Design are presented. Topics covered include: computer aided design; object oriented programming; airfoil design; surveillance aircraft; commercial aircraft; aircraft design; and launch vehicles.

  9. A kind of optimizing design method of progressive addition lenses

    NASA Astrophysics Data System (ADS)

    Tang, Yunhai; Qian, Lin; Wu, Quanying; Yu, Jingchi; Chen, Hao; Wang, Yuanyuan

    2010-10-01

    Progressive addition lenses are a kind of ophthalmic lenses with freeform surface. The surface curvature of the progressive addition lenses varies gradually from a minimum value in the upper, distance-viewing area, to a maximum value in the lower, near-viewing area. A kind of optimizing design method of progressive addition lenses is proposed to improve the optical quality by modifying the vector heights of the surface of designed progressive addition lenses initially. The relationship among mean power, cylinder power and the vector heights of the surface is deduced, and the optimizing factor is also gained. The vector heights of the surface of designed progressive addition lenses initially are used to calculate the plots of mean power and cylinder power based on the principle of differential geometry. The mean power plot is changed by adjusting the optimizing factor. Otherwise, the novel plot of the mean power can also be derived by shifting the mean power of one selected region to another and then by interpolating and smoothing. A partial differential equation of the elliptic type is founded based on the changed mean power. The solution of the equation is achieved by iterative method. The optimized vector heights of the surface are solved out. Compared with the original lens, the region in which the astigmatism near the nasal side on distance-vision portion is less than 0.5 D has become broader, and the clear regions on distance-vision and near-vision portion are wider.

  10. Optimal Design of General Stiffened Composite Circular Cylinders for Global Buckling with Strength Constraints

    NASA Technical Reports Server (NTRS)

    Jaunky, N.; Ambur, D. R.; Knight, N. F., Jr.

    1998-01-01

    A design strategy for optimal design of composite grid-stiffened cylinders subjected to global and local buckling constraints and strength constraints was developed using a discrete optimizer based on a genetic algorithm. An improved smeared stiffener theory was used for the global analysis. Local buckling of skin segments were assessed using a Rayleigh-Ritz method that accounts for material anisotropy. The local buckling of stiffener segments were also assessed. Constraints on the axial membrane strain in the skin and stiffener segments were imposed to include strength criteria in the grid-stiffened cylinder design. Design variables used in this study were the axial and transverse stiffener spacings, stiffener height and thickness, skin laminate stacking sequence and stiffening configuration, where stiffening configuration is a design variable that indicates the combination of axial, transverse and diagonal stiffener in the grid-stiffened cylinder. The design optimization process was adapted to identify the best suited stiffening configurations and stiffener spacings for grid-stiffened composite cylinder with the length and radius of the cylinder, the design in-plane loads and material properties as inputs. The effect of having axial membrane strain constraints in the skin and stiffener segments in the optimization process is also studied for selected stiffening configurations.

  11. Rare Potassium-Bearing Mica in Allan Hills 84001: Additional Constraints on Carbonate Formation

    NASA Technical Reports Server (NTRS)

    Brearley, A. J.

    1998-01-01

    There have been presented several intriguing observations suggesting evidence of fossil life in martian orthopyroxenite ALH 84001. These exciting and controversial observations have stimulated extensive debate over the origin and history of ALH 84001, but many issues still remain unresolved. Among the most important is the question of the temperature at which the carbonates, which host the putative microfossils, formed. Oxygen- isotopic data, while showing that the carbonates are generally out of isotopic equilibria with the host rock, cannot constrain their temperature of formation. Both low- and high-temperature scenarios are plausible depending on whether carbonate growth occurred in an open or closed system. Petrographic arguments have generally been used to support a high-temperature origin but these appear to be suspect because they assume equilibrium between carbonate compositions that are not in contact. Some observations appear to be consistent with shock mobilization and growth from immiscible silicate-carbonate melts at high temperatures. Proponents of a low-temperature origin for the carbonates are hampered by the fact that there is currently no evidence of hydrous phases that would indicate low temperatures and the presence of a hydrous fluid during the formation of the carbonates. However, the absence of hydrous phases does not rule out carbonate formation at low temperatures, because the carbonate forming fluids may have been extremely CO2 rich, such that hydrous phases would not have been stabilized. In this study, I have carried out additional Transmission electron microscopy (TEM) studies of ALH-84001 and have found evidence of very rare phyllosilicates, which appear to be convincingly of pre-terrestrial origin. At present these observations are limited to one occurrence: further studies are in progress to determine if the phyllosilicates are more widespread.

  12. DESAP 1: A structural design program with stress and displacement constraints. Volume 1: Theoretical and user's manual

    NASA Technical Reports Server (NTRS)

    Kiusalaas, J.; Reddy, G. B.

    1977-01-01

    A finite element program is presented for computer-automated, minimum weight design of elastic structures with constraints on stresses (including local instability criteria) and displacements. Volume 1 of the report contains the theoretical and user's manual of the program. Sample problems and the listing of the program are included in Volumes 2 and 3. The element subroutines are organized so as to facilitate additions and changes by the user. As a result, a relatively minor programming effort would be required to make DESAP 1 into a special purpose program to handle the user's specific design requirements and failure criteria.

  13. Courtyard Commons retail addition. Phase I. Final design documentation

    SciTech Connect

    Not Available

    1981-04-25

    The project consists of a retail addition to an existing cluster of buildings located on the main commercial street in Santa Cruz, California. The existing complex is formed by two wings of one-story buildings enclosing an open courtyard now used for circulation, a coffee shop seating area, a flower stand, and access to four retail stores. The program calls for an addition of new retail space above the existing buildings constructed of eight inch concrete blocks. In order to provide for the year around use of the courtyard, the program also calls for a flexible glass cover which could be removed during the sunny warm summer days. The main requirements of the program finally, are to develop an energy efficient and cost effective design which uses natural light at its full potential for both the courtyard and interior spaces. This report includes sections of the following: overview of final design; unavailable solar design information; incremental passive design cost, energy performance analysis and results; economic analysis and results; architectural compatibility; NBSGLD output and documentation; and design development drawings.

  14. Tribological design constraints of marine renewable energy systems.

    PubMed

    Wood, Robert J K; Bahaj, AbuBakr S; Turnock, Stephen R; Wang, Ling; Evans, Martin

    2010-10-28

    Against the backdrop of increasing energy demands, the threat of climate change and dwindling fuel reserves, finding reliable, diverse, sustainable/renewable, affordable energy resources has become a priority for many countries. Marine energy conversion systems are at the forefront of providing such a resource. Most marine renewable energy conversion systems require tribological components to convert wind or tidal streams to rotational motion for generating electricity while wave machines typically use oscillating hinge or piston within cylinder geometries to promote reciprocating linear motion. This paper looks at the tribology of three green marine energy systems, offshore wind, tidal and wave machines. Areas covered include lubrication and contamination, bearing and gearbox issues, biofouling, cavitation erosion, tribocorrosion, condition monitoring as well as design trends and loading conditions associated with tribological components. Current research thrusts are highlighted along with areas needing research as well as addressing present-day issues related to the tribology of offshore energy conversion technologies.

  15. Applying Additive Manufacturing to a New Liquid Oxygen Turbopump Design

    NASA Technical Reports Server (NTRS)

    O'Neal, Derek

    2016-01-01

    A liquid oxygen turbopump has been designed at Marshall Space Flight Center as part of the in-house, Advanced Manufacturing Demonstrator Engine (AMDE) project. Additive manufacturing, specifically direct metal laser sintering (DMLS) of Inconel 718, is used for 77% of the parts by mass. These parts include the impeller, turbine components, and housings. The near-net shape DMLS parts have been delivered and final machining is underway. Fabrication of the traditionally manufactured hardware is also proceeding. Testing in liquid oxygen is planned for Q2 of FY2017. This topic explores the design of the turbopump along with fabrication and material testing of the DMLS hardware.

  16. An efficient constraint to account for mistuning effects in the optimal design of engine rotors

    NASA Technical Reports Server (NTRS)

    Murthy, Durbha V.; Pierre, Christophe; Ottarsson, Gisli

    1992-01-01

    Blade-to-blade differences in structural properties, unavoidable in practice due to manufacturing tolerances, can have significant influence on the vibratory response of engine rotor blade. Accounting for these differences, also known as mistuning, in design and in optimization procedures is generally not possible. This note presents an easily calculated constraint that can be used in design and optimization procedures to control the sensitivity of final designs to mistuning.

  17. Constraint-based component-modeling for knowledge-based design

    NASA Technical Reports Server (NTRS)

    Kolb, Mark A.

    1992-01-01

    The paper describes the application of various advanced programming techniques derived from artificial intelligence research to the development of flexible design tools for conceptual design. Special attention is given to two techniques which appear to be readily applicable to such design tools: the constraint propagation technique and the object-oriented programming. The implementation of these techniques in a prototype computer tool, Rubber Airplane, is described.

  18. A methodology and a tool for the computer aided design with constraints of electrical devices

    SciTech Connect

    Wurtz, F.; Bigeon, J.; Poirson, C.

    1996-05-01

    A methodology for the computer aided constrained design of electrical devices is presented and validated through the design of a slotless permanent structure. It is based on the use of the analytical design equations of the device. Symbolic calculation is widely used to generate an analysis program and a sensitivity computation program. Those programs are linked with an optimization algorithm that can take constraints into account. The methodology is tested with an experimental software named PASCOSMA.

  19. Linear Quadratic Tracking Design for a Generic Transport Aircraft with Structural Load Constraints

    NASA Technical Reports Server (NTRS)

    Burken, John J.; Frost, Susan A.; Taylor, Brian R.

    2011-01-01

    When designing control laws for systems with constraints added to the tracking performance, control allocation methods can be utilized. Control allocations methods are used when there are more command inputs than controlled variables. Constraints that require allocators are such task as; surface saturation limits, structural load limits, drag reduction constraints or actuator failures. Most transport aircraft have many actuated surfaces compared to the three controlled variables (such as angle of attack, roll rate & angle of side slip). To distribute the control effort among the redundant set of actuators a fixed mixer approach can be utilized or online control allocation techniques. The benefit of an online allocator is that constraints can be considered in the design whereas the fixed mixer cannot. However, an online control allocator mixer has a disadvantage of not guaranteeing a surface schedule, which can then produce ill defined loads on the aircraft. The load uncertainty and complexity has prevented some controller designs from using advanced allocation techniques. This paper considers actuator redundancy management for a class of over actuated systems with real-time structural load limits using linear quadratic tracking applied to the generic transport model. A roll maneuver example of an artificial load limit constraint is shown and compared to the same no load limitation maneuver.

  20. CONSTRICTOR: Constraint Modification Provides Insight into Design of Biochemical Networks

    PubMed Central

    Erickson, Keesha E.; Gill, Ryan T.; Chatterjee, Anushree

    2014-01-01

    Advances in computational methods that allow for exploration of the combinatorial mutation space are needed to realize the potential of synthetic biology based strain engineering efforts. Here, we present Constrictor, a computational framework that uses flux balance analysis (FBA) to analyze inhibitory effects of genetic mutations on the performance of biochemical networks. Constrictor identifies engineering interventions by classifying the reactions in the metabolic model depending on the extent to which their flux must be decreased to achieve the overproduction target. The optimal inhibition of various reaction pathways is determined by restricting the flux through targeted reactions below the steady state levels of a baseline strain. Constrictor generates unique in silico strains, each representing an “expression state”, or a combination of gene expression levels required to achieve the overproduction target. The Constrictor framework is demonstrated by studying overproduction of ethylene in Escherichia coli network models iAF1260 and iJO1366 through the addition of the heterologous ethylene-forming enzyme from Pseudomonas syringae. Targeting individual reactions as well as combinations of reactions reveals in silico mutants that are predicted to have as high as 25% greater theoretical ethylene yields than the baseline strain during simulated exponential growth. Altering the degree of restriction reveals a large distribution of ethylene yields, while analysis of the expression states that return lower yields provides insight into system bottlenecks. Finally, we demonstrate the ability of Constrictor to scan networks and provide targets for a range of possible products. Constrictor is an adaptable technique that can be used to generate and analyze disparate populations of in silico mutants, select gene expression levels and provide non-intuitive strategies for metabolic engineering. PMID:25422896

  1. Progressive addition lens design by optimizing NURBS surface

    NASA Astrophysics Data System (ADS)

    Liu, Yen-Liang; Hsu, Wei-Yao; Cheng, Yuan-Chieh; Su, Guo-Dung

    2011-10-01

    Progressive addition lenses (PAL) are used to compensate presbyopia, which is induced by losing accommodation of elder eyes. These eyes need different optical power provided by eye glasses while watching objects at different distance. A smaller optical power is required in further distance and a larger one in nearer zone. A progressive addition lens can provides different power requirements in one piece of lens. This paper introduces a whole process of PAL production, from design, fabrication, to measurement. The PAL is designed by optimizing NURBS surface. Parameters of merit function are adjusted to design lenses with different specifications. The simulation results confirm that the power distributes as expected and cylinders are controlled under an acceptable level. Besides, sample lenses have been fabricated and measured. We apply precise-machining to produce the molds for plastic injection. Then, the samples are produced by injecting polycorbonate to the molds. Finally, Ultra Accuracy 3D Profilemeter is used to measure the sample PALs. Practical examinations shows that our designs are achievable and feasible in practice use.

  2. Integration of additional constraints to Inverse the differential kinematic model for a nonholonomic and redundant mobile manipulator

    NASA Astrophysics Data System (ADS)

    Akli, Isma; Achour, Noura

    2008-06-01

    This article presents a differential kinematic study for a car-like mobile system carrying a four degrees of freedom manipulator. The generalized coordinates and velocities of the mobile manipulator are required, when the position and the velocity of the end-effector are imposed in the cartesian space. Our approach consists of planning the motion of the mobile platform with make the onboard manipulator able to follow the cartesian trajectory. The resulted generalized coordinates are exploited to calculate the Forward Differential Kinematic Model. Since the mobile manipulator is redundant regarding to the task, we profit from the system characteristics to augment the jacobian matrix, while integrating additional constraints, to inverse the differential kinematic model.

  3. Understanding Enactivism: A Study of Affordances and Constraints of Engaging Practicing Teachers as Digital Game Designers

    ERIC Educational Resources Information Center

    Li, Qing

    2012-01-01

    This study is intended to deepen our understanding of enactivism, an emergent theoretical paradigm, through empirical exploration of teacher undertakings as digital game creators. Specifically, it explores the affordances and constraints, two important enactivism concepts, of practicing teachers' experiences in designing and developing games for…

  4. Embracing additive manufacture: implications for foot and ankle orthosis design

    PubMed Central

    2012-01-01

    Background The design of foot and ankle orthoses is currently limited by the methods used to fabricate the devices, particularly in terms of geometric freedom and potential to include innovative new features. Additive manufacturing (AM) technologies, where objects are constructed via a series of sub-millimetre layers of a substrate material, may present the opportunity to overcome these limitations and allow novel devices to be produced that are highly personalised for the individual, both in terms of fit and functionality. Two novel devices, a foot orthosis (FO) designed to include adjustable elements to relieve pressure at the metatarsal heads, and an ankle foot orthosis (AFO) designed to have adjustable stiffness levels in the sagittal plane, were developed and fabricated using AM. The devices were then tested on a healthy participant to determine if the intended biomechanical modes of action were achieved. Results The adjustable, pressure relieving FO was found to be able to significantly reduce pressure under the targeted metatarsal heads. The AFO was shown to have distinct effects on ankle kinematics which could be varied by adjusting the stiffness level of the device. Conclusions The results presented here demonstrate the potential design freedom made available by AM, and suggest that it may allow novel personalised orthotic devices to be produced which are beyond the current state of the art. PMID:22642941

  5. Physical Constraints on Biological Integral Control Design for Homeostasis and Sensory Adaptation

    PubMed Central

    Ang, Jordan; McMillen, David R.

    2013-01-01

    Synthetic biology includes an effort to use design-based approaches to create novel controllers, biological systems aimed at regulating the output of other biological processes. The design of such controllers can be guided by results from control theory, including the strategy of integral feedback control, which is central to regulation, sensory adaptation, and long-term robustness. Realization of integral control in a synthetic network is an attractive prospect, but the nature of biochemical networks can make the implementation of even basic control structures challenging. Here we present a study of the general challenges and important constraints that will arise in efforts to engineer biological integral feedback controllers or to analyze existing natural systems. Constraints arise from the need to identify target output values that the combined process-plus-controller system can reach, and to ensure that the controller implements a good approximation of integral feedback control. These constraints depend on mild assumptions about the shape of input-output relationships in the biological components, and thus will apply to a variety of biochemical systems. We summarize our results as a set of variable constraints intended to provide guidance for the design or analysis of a working biological integral feedback controller. PMID:23442873

  6. Additives

    NASA Technical Reports Server (NTRS)

    Smalheer, C. V.

    1973-01-01

    The chemistry of lubricant additives is discussed to show what the additives are chemically and what functions they perform in the lubrication of various kinds of equipment. Current theories regarding the mode of action of lubricant additives are presented. The additive groups discussed include the following: (1) detergents and dispersants, (2) corrosion inhibitors, (3) antioxidants, (4) viscosity index improvers, (5) pour point depressants, and (6) antifouling agents.

  7. Design and calibration of zero-additional-phase SPIDER

    SciTech Connect

    Baum, Peter; Riedle, Eberhard

    2005-09-01

    Zero-additional-phase spectral phase interferometry for direct electric field reconstruction (ZAP-SPIDER) is a novel technique for measuring the temporal shape and phase of ultrashort optical pulses directly at the interaction point of a spectroscopic experiment. The scheme is suitable for an extremely wide wavelength region from the ultraviolet to the near infrared. We present a comprehensive description of the experimental setup and design guidelines to effectively apply the technique to various wavelengths and pulse durations. The calibration of the setup and procedures to check the consistency of the measurement are discussed in detail. We show experimental data for various center wavelengths and pulse durations down to 7 fs to verify the applicability to a wide range of pulse parameters.

  8. LV wall segmentation using the variational level set method (LSM) with additional shape constraint for oedema quantification

    NASA Astrophysics Data System (ADS)

    Kadir, K.; Gao, H.; Payne, A.; Soraghan, J.; Berry, C.

    2012-10-01

    In this paper an automatic algorithm for the left ventricle (LV) wall segmentation and oedema quantification from T2-weighted cardiac magnetic resonance (CMR) images is presented. The extent of myocardial oedema delineates the ischaemic area-at-risk (AAR) after myocardial infarction (MI). Since AAR can be used to estimate the amount of salvageable myocardial post-MI, oedema imaging has potential clinical utility in the management of acute MI patients. This paper presents a new scheme based on the variational level set method (LSM) with additional shape constraint for the segmentation of T2-weighted CMR image. In our approach, shape information of the myocardial wall is utilized to introduce a shape feature of the myocardial wall into the variational level set formulation. The performance of the method is tested using real CMR images (12 patients) and the results of the automatic system are compared to manual segmentation. The mean perpendicular distances between the automatic and manual LV wall boundaries are in the range of 1-2 mm. Bland-Altman analysis on LV wall area indicates there is no consistent bias as a function of LV wall area, with a mean bias of -121 mm2 between individual investigator one (IV1) and LSM, and -122 mm2 between individual investigator two (IV2) and LSM when compared to two investigators. Furthermore, the oedema quantification demonstrates good correlation when compared to an expert with an average error of 9.3% for 69 slices of short axis CMR image from 12 patients.

  9. Adaptive fuzzy switched control design for uncertain nonholonomic systems with input nonsmooth constraint

    NASA Astrophysics Data System (ADS)

    Li, Yongming; Tong, Shaocheng

    2016-10-01

    In this paper, a fuzzy adaptive switched control approach is proposed for a class of uncertain nonholonomic chained systems with input nonsmooth constraint. In the control design, an auxiliary dynamic system is designed to address the input nonsmooth constraint, and an adaptive switched control strategy is constructed to overcome the uncontrollability problem associated with x0(t0) = 0. By using fuzzy logic systems to tackle unknown nonlinear functions, a fuzzy adaptive control approach is explored based on the adaptive backstepping technique. By constructing the combination approximation technique and using Young's inequality scaling technique, the number of the online learning parameters is reduced to n and the 'explosion of complexity' problem is avoid. It is proved that the proposed method can guarantee that all variables of the closed-loop system converge to a small neighbourhood of zero. Two simulation examples are provided to illustrate the effectiveness of the proposed control approach.

  10. Conceptual Design Optimization of an Augmented Stability Aircraft Incorporating Dynamic Response Performance Constraints

    NASA Technical Reports Server (NTRS)

    Welstead, Jason

    2014-01-01

    This research focused on incorporating stability and control into a multidisciplinary de- sign optimization on a Boeing 737-class advanced concept called the D8.2b. A new method of evaluating the aircraft handling performance using quantitative evaluation of the sys- tem to disturbances, including perturbations, continuous turbulence, and discrete gusts, is presented. A multidisciplinary design optimization was performed using the D8.2b transport air- craft concept. The con guration was optimized for minimum fuel burn using a design range of 3,000 nautical miles. Optimization cases were run using xed tail volume coecients, static trim constraints, and static trim and dynamic response constraints. A Cessna 182T model was used to test the various dynamic analysis components, ensuring the analysis was behaving as expected. Results of the optimizations show that including stability and con- trol in the design process drastically alters the optimal design, indicating that stability and control should be included in conceptual design to avoid system level penalties later in the design process.

  11. Restoring natural geomorphic process to river environments influenced by practical design constraints

    NASA Astrophysics Data System (ADS)

    Moir, H. J.

    2015-12-01

    The process restoration philosophy promotes the reinstatement of natural process (particularly the continuum of sediment transport processes) at the catchment scale. Associated with this approach is the concept that river biological communities, having evolved under natural/ un-impacted conditions, will respond positively to the reinstatement of natural physical function. The application of this 'let-the-river-do-the-work' approach is regarded as providing a sustainable alternative to traditional more 'hard engineering' approaches. However, often the reality is that full restoration of the controlling physical processes at the catchment scale is not feasible due to a variety of constraints (e.g. altered geomorphic regime, agriculture, infrastructure/ services, urban development, costs, etc.) and less ambitious objectives have to be set. Thus, under these typical constrained circumstances, can process restoration still be applied and, given the fundamental assumption of biophysical linkage, can ecology still be expected to respond positively? To elucidate these issues, we present four case studies from Scotland which represent the spectrum of process restoration application relating to almost no design constraints to very significant limitations (culvert daylighting within a housing development). We highlight that, despite significant constraints, physical river processes can (and should) always be considered in restoration design. The case studies demonstrate that natural physical processes (evidenced through indicators of sediment transport) quickly reinstate following construction; this was despite significant local constraints but reliant on physical/ geomorphic process being explicitly incorporated into to the design approach. Furthermore, evidence of associated improvements to the ecological/ habitat/ biotic condition of the restored sections of river were observed.

  12. LV wall segmentation using the variational level set method (LSM) with additional shape constraint for oedema quantification.

    PubMed

    Kadir, K; Gao, H; Payne, A; Soraghan, J; Berry, C

    2012-10-01

    In this paper an automatic algorithm for the left ventricle (LV) wall segmentation and oedema quantification from T2-weighted cardiac magnetic resonance (CMR) images is presented. The extent of myocardial oedema delineates the ischaemic area-at-risk (AAR) after myocardial infarction (MI). Since AAR can be used to estimate the amount of salvageable myocardial post-MI, oedema imaging has potential clinical utility in the management of acute MI patients. This paper presents a new scheme based on the variational level set method (LSM) with additional shape constraint for the segmentation of T2-weighted CMR image. In our approach, shape information of the myocardial wall is utilized to introduce a shape feature of the myocardial wall into the variational level set formulation. The performance of the method is tested using real CMR images (12 patients) and the results of the automatic system are compared to manual segmentation. The mean perpendicular distances between the automatic and manual LV wall boundaries are in the range of 1-2 mm. Bland-Altman analysis on LV wall area indicates there is no consistent bias as a function of LV wall area, with a mean bias of -121 mm(2) between individual investigator one (IV1) and LSM, and -122 mm(2) between individual investigator two (IV2) and LSM when compared to two investigators. Furthermore, the oedema quantification demonstrates good correlation when compared to an expert with an average error of 9.3% for 69 slices of short axis CMR image from 12 patients.

  13. Evaluation of critical materials in five additional advance design photovoltaic cells

    SciTech Connect

    Smith, S.A.; Watts, R.L.; Martin, P.; Gurwell, W.E.

    1981-02-01

    The objective of this study is to identify potential material supply constraints due to the large-scale deployment of five advanced photovoltaic (PV) cell designs, and to suggest strategies to reduce the impacts of these production capacity limitations and potential future material shortages. The Critical Materials Assessment Program (CMAP) screens the designs and their supply chains and identifies potential shortages which might preclude large-scale use of the technologies. The results of the screening of five advanced PV cell designs are presented: (1) indium phosphide/cadmium sulfide, (2) zinc phosphide, (3) cadmium telluride/cadmium sulfide, (4) copper indium selenium, and (5) cadmium selenide photoelectrochemical. Each of these five cells is screened individually assuming that they first come online in 1991, and that 25 Gwe of peak capacity is online by the year 2000. A second computer screening assumes that each cell first comes online in 1991 and that each cell has a 5 GWe of peak capacity by the year 2000, so that the total online capacity for the five cells is 25 GWe. Based on a review of the preliminary baseline screening results, suggestions were made for varying such parameters as the layer thickness, cell production processes, etc. The resulting PV cell characterizations were then screened again by the CMAP computer code. The CMAP methodology used to identify critical materials is described; and detailed characterizations of the advanced photovoltaic cell designs under investigation, descriptions of additional cell production processes, and the results are presented. (WHK)

  14. 49 CFR 173.412 - Additional design requirements for Type A packages.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Additional design requirements for Type A packages. In addition to meeting the general design requirements... gas by chemical reaction and radiolysis. (f) The containment system will retain its...

  15. 49 CFR 173.412 - Additional design requirements for Type A packages.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Additional design requirements for Type A packages. In addition to meeting the general design requirements... gas by chemical reaction and radiolysis. (f) The containment system will retain its...

  16. 49 CFR 173.412 - Additional design requirements for Type A packages.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Additional design requirements for Type A packages. In addition to meeting the general design requirements... gas by chemical reaction and radiolysis. (f) The containment system will retain its...

  17. 49 CFR 173.412 - Additional design requirements for Type A packages.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Additional design requirements for Type A packages. In addition to meeting the general design requirements... gas by chemical reaction and radiolysis. (f) The containment system will retain its...

  18. A multilevel approach for minimum weight structural design including local and system buckling constraints

    NASA Technical Reports Server (NTRS)

    Schmit, L. A., Jr.; Ramanathan, R. K.

    1977-01-01

    A rational multilevel approach for minimum weight structural design of truss and wing structures including local and system buckling constraints is presented. Overall proportioning of the structure is achieved at the system level subject to strength, displacement and system buckling constraints, while the detailed component designs are carried out separately at the component level satisfying local buckling constraints. Total structural weight is taken to be the objective function at the system level while employing the change in the equivalent system stiffness of the component as the component level objective function. Finite element analysis is used to predict static response while system buckling behavior is handled by incorporating a geometric stiffness matrix capability. Buckling load factors and the corresponding mode shapes are obtained by solving the eigenvalue problem associated with the assembled elastic stiffness and geometric stiffness matrices for the structural system. At the component level various local buckling failure modes are guarded against using semi-empirical formulas. Mathematical programming techniques are employed at both the system and component level.

  19. Feature, design intention and constraint preservation for direct modeling of 3D freeform surfaces

    NASA Astrophysics Data System (ADS)

    Fu, Luoting; Kara, Levent Burak; Shimada, Kenji

    2012-06-01

    Direct modeling has recently emerged as a suitable approach for 3D free-form shape modeling in industrial design. It has several advantages over the conventional, parametric modeling techniques, including natural user interactions, as well as the underlying, automatic feature-preserving shape deformation algorithms. However, current direct modeling packages still lack several capabilities critical for product design, such as managing aesthetic design intentions, and enforcing dimensional, geometric constraints. In this paper, we describe a novel 3D surface editing system capable of jointly accommodating aesthetic design intentions expressed in the form of surface painting and color-coded annotations, as well as engineering constraints expressed as dimensions. The proposed system is built upon differential coordinates and constrained least squares, and is intended for conceptual design that involves frequent shape tuning and explorations. We also provide an extensive review of the state-of-the-art direct modeling approaches for 3D mesh-based, freeform surfaces, with an emphasis on the two broad categories of shape deformation algorithms developed in the relevant field of geometric modeling. [Figure not available: see fulltext.

  20. Conceptual Design Optimization of an Augmented Stability Aircraft Incorporating Dynamic Response and Actuator Constraints

    NASA Technical Reports Server (NTRS)

    Welstead, Jason; Crouse, Gilbert L., Jr.

    2014-01-01

    Empirical sizing guidelines such as tail volume coefficients have long been used in the early aircraft design phases for sizing stabilizers, resulting in conservatively stable aircraft. While successful, this results in increased empty weight, reduced performance, and greater procurement and operational cost relative to an aircraft with optimally sized surfaces. Including flight dynamics in the conceptual design process allows the design to move away from empirical methods while implementing modern control techniques. A challenge of flight dynamics and control is the numerous design variables, which are changing fluidly throughout the conceptual design process, required to evaluate the system response to some disturbance. This research focuses on addressing that challenge not by implementing higher order tools, such as computational fluid dynamics, but instead by linking the lower order tools typically used within the conceptual design process so each discipline feeds into the other. In thisresearch, flight dynamics and control was incorporated into the conceptual design process along with the traditional disciplines of vehicle sizing, weight estimation, aerodynamics, and performance. For the controller, a linear quadratic regulator structure with constant gains has been specified to reduce the user input. Coupling all the disciplines in the conceptual design phase allows the aircraft designer to explore larger design spaces where stabilizers are sized according to dynamic response constraints rather than historical static margin and volume coefficient guidelines.

  1. Hybrid method for designing digital FIR filters based on fractional derivative constraints.

    PubMed

    Baderia, Kuldeep; Kumar, Anil; Kumar Singh, Girish

    2015-09-01

    In this manuscript, a hybrid approach based on Lagrange multiplier method and cuckoo search (CS) optimization technique is proposed for the design of linear phase finite impulse response (FIR) filters using fractional derivative constraints. In the proposed method, FIR filter is designed by optimizing the integral squares in passband and stopband from ideal response such that the fractional derivatives of designed filter response become zero at a given frequency point. Lagrange multiplier method is exploited for finding the optimized filter coefficients. Optimal value of fractional derivative constraints for optimized filter coefficients are determined by minimizing the objective function constructed using a sum of maximum passband ripple and maximum stopband ripple in frequency domain using CS algorithm. Performance of the proposed method is evaluated by passband error (ϕ(p)), stopband error (ϕ(s)), stopband attenuation (A(s)), maximum passband ripple (MPR), maximum stopband ripple (MSR) and CPU time. A comparative study of the performance of particle swarm optimization (PSO) and artificial bee colony (ABC) for designing FIR filters using the proposed method is also made. PMID:26142984

  2. Structural design optimization with survivability dependent constraints application: Primary wing box of a multi-role fighter

    NASA Technical Reports Server (NTRS)

    Dolvin, Douglas J.

    1992-01-01

    The superior survivability of a multirole fighter is dependent upon balanced integration of technologies for reduced vulnerability and susceptability. The objective is to develop a methodology for structural design optimization with survivability dependent constraints. The design criteria for optimization will be survivability in a tactical laser environment. The following analyses are studied to establish a dependent design relationship between structural weight and survivability: (1) develop a physically linked global design model of survivability variables; and (2) apply conventional constraints to quantify survivability dependent design. It was not possible to develop an exact approach which would include all aspects of survivability dependent design, therefore guidelines are offered for solving similar problems.

  3. Optimum design using VICONOPT, a buckling and strength constraint program for prismatic assemblies of anisotropic plates

    NASA Technical Reports Server (NTRS)

    Butler, R.; Williams, F. W.

    1992-01-01

    A computer program for obtaining the optimum (least mass) dimensions of the kind of prismatic assemblies of laminated, composite plates which occur in advanced aerospace construction is described. Rigorous buckling analysis (derived from exact member theory) and a tailored design procedure are used to produce designs which satisfy buckling and material strength constraints and configurational requirements. Analysis is two to three orders of magnitude quicker than FEM, keeps track of all the governing modes of failure and is efficiently adapted to give sensitivities and to maintain feasibility. Tailoring encourages convergence in fewer sizing cycles than competing programs and permits start designs which are a long way from feasible and/or optimum. Comparisons with its predecessor, PASCO, show that the program is more likely to produce an optimum, will do so more quickly in some cases, and remains accurate for a wider range of problems.

  4. Sensor and Display Human Factors Based Design Constraints for Head Mounted and Tele-Operation Systems

    PubMed Central

    Harrison, Andre; Mullins, Linda; Etienne-Cummings, Ralph

    2011-01-01

    For mobile imaging systems in head mounted displays and tele-operation systems it is important to maximize the amount of visual information transmitted to the human visual system without exceeding its input capacity. This paper aims to describe the design constraints on the imager and display systems of head mounted devices and tele-operated systems based upon the capabilities of the human visual system. We also present the experimental results of methods to improve the amount of visual information conveyed to a user when trying to display a high dynamic range image on a low dynamic range display. PMID:22319370

  5. Effect of Tip-Speed Constraints on the Optimized Design of a Wind Turbine

    SciTech Connect

    Dykes, K.; Resor, B.; Platt, A.; Guo, Y.; Ning, A.; King, R.; Parsons, T.; Petch, D.; Veers, P.

    2014-10-01

    This study investigates the effect of tip-velocity constraints on system levelized cost of energy (LCOE). The results indicate that a change in maximum tip speed from 80 to 100~m/s could produce a 32% decrease in gearbox weight (a 33% reduction in cost) which would result in an overall reduction of 1%-9% in system LCOE depending on the design approach. Three 100~m/s design cases were considered including a low tip-speed ratio/high-solidity rotor design, a high tip-speed ratio/ low-solidity rotor design, and finally a flexible blade design in which a high tip-speed ratio was used along with removing the tip deflection constraint on the rotor design. In all three cases, the significant reduction in gearbox weight caused by the higher tip-speed and lower overall gear ratio was counterbalanced by increased weights for the rotor and/or other drivetrain components and the tower. As a result, the increased costs of either the rotor or drivetrain components offset the overall reduction in turbine costs from down-sizing the gearbox. Other system costs were not significantly affected, whereas energy production was slightly reduced in the 100~m/s case low tip-speed ratio case and increased in the high tip-speed ratio case. This resulted in system cost of energy reductions moving from the 80~m/s design to the 100~m/s designs of 1.2% for the low tip-speed ratio, 4.6% for the high tip-speed ratio, and 9.5% for the final flexible case (the latter result is optimistic because the impact of deflection of the flexible blade on power production was not modeled). Overall, the results demonstrate that there is a trade-off in system design between the maximum tip velocity and the overall wind plant cost of energy, and there are many trade-offs within the overall system in designing a turbine for a high maximum tip velocity.

  6. Using Generalized Additive Models to Analyze Single-Case Designs

    ERIC Educational Resources Information Center

    Shadish, William; Sullivan, Kristynn

    2013-01-01

    Many analyses for single-case designs (SCDs)--including nearly all the effect size indicators-- currently assume no trend in the data. Regression and multilevel models allow for trend, but usually test only linear trend and have no principled way of knowing if higher order trends should be represented in the model. This paper shows how Generalized…

  7. Constraint-based strain design using continuous modifications (CosMos) of flux bounds finds new strategies for metabolic engineering.

    PubMed

    Cotten, Cameron; Reed, Jennifer L

    2013-05-01

    In recent years, a growing number of metabolic engineering strain design techniques have employed constraint-based modeling to determine metabolic and regulatory network changes which are needed to improve chemical production. These methods use systems-level analysis of metabolism to help guide experimental efforts by identifying deletions, additions, downregulations, and upregulations of metabolic genes that will increase biological production of a desired metabolic product. In this work, we propose a new strain design method with continuous modifications (CosMos) that provides strategies for deletions, downregulations, and upregulations of fluxes that will lead to the production of the desired products. The method is conceptually simple and easy to implement, and can provide additional strategies over current approaches. We found that the method was able to find strain design strategies that required fewer modifications and had larger predicted yields than strategies from previous methods in example and genome-scale networks. Using CosMos, we identified modification strategies for producing a variety of metabolic products, compared strategies derived from Escherichia coli and Saccharomyces cerevisiae metabolic models, and examined how imperfect implementation may affect experimental outcomes. This study gives a powerful and flexible technique for strain engineering and examines some of the unexpected outcomes that may arise when strategies are implemented experimentally.

  8. Heuristic optimization of pressurized water reactor fuel cycle design under general constraints

    SciTech Connect

    Moon, H.; Levine, S.H. ); Mahgerefteh, M. )

    1989-12-01

    Optimization techniques in fuel management have directed modern fuel cycle designs to use low-leakage loading patterns. Future optimization calculations involving low-leakage patterns must utilize nucleonic models that are both fast operationally and rigorous. A two-dimensional two-group diffusion theory code is developed and lattice homogenization constants are generated using a modified LEOPARD code to fulfill these criteria. Based on these two codes, a heuristic optimization study is performed that considers the general constraints (e.g., spent-fuel storage limit and mechanical burnup limit) given to a utility fuel cycle designer. The optimum cycle length that minimizes the fuel cost is {approximately} 600 effective full-power days for the conditions assumed.

  9. 49 CFR 192.112 - Additional design requirements for steel pipe using alternative maximum allowable operating...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Additional design requirements for steel pipe...: MINIMUM FEDERAL SAFETY STANDARDS Pipe Design § 192.112 Additional design requirements for steel pipe using... segment must meet the following additional design requirements. Records for alternative MAOP must...

  10. Concentric Tube Robot Design and Optimization Based on Task and Anatomical Constraints

    PubMed Central

    Bergeles, Christos; Gosline, Andrew H.; Vasilyev, Nikolay V.; Codd, Patrick J.; del Nido, Pedro J.; Dupont, Pierre E.

    2015-01-01

    Concentric tube robots are catheter-sized continuum robots that are well suited for minimally invasive surgery inside confined body cavities. These robots are constructed from sets of pre-curved superelastic tubes and are capable of assuming complex 3D curves. The family of 3D curves that the robot can assume depends on the number, curvatures, lengths and stiffnesses of the tubes in its tube set. The robot design problem involves solving for a tube set that will produce the family of curves necessary to perform a surgical procedure. At a minimum, these curves must enable the robot to smoothly extend into the body and to manipulate tools over the desired surgical workspace while respecting anatomical constraints. This paper introduces an optimization framework that utilizes procedureor patient-specific image-based anatomical models along with surgical workspace requirements to generate robot tube set designs. The algorithm searches for designs that minimize robot length and curvature and for which all paths required for the procedure consist of stable robot configurations. Two mechanics-based kinematic models are used. Initial designs are sought using a model assuming torsional rigidity. These designs are then refined using a torsionally-compliant model. The approach is illustrated with clinically relevant examples from neurosurgery and intracardiac surgery. PMID:26380575

  11. The paradox of conformational constraint in the design of Cbl(TKB)-binding peptides

    PubMed Central

    Kumar, Eric A.; Chen, Qianyi; Kizhake, Smitha; Kolar, Carol; Kang, Myungshim; Chang, Chia-en A.; Borgstahl, Gloria E. O.; Natarajan, Amarnath

    2013-01-01

    Solving the crystal structure of Cbl(TKB) in complex with a pentapeptide, pYTPEP, revealed that the PEP region adopted a poly-L-proline type II (PPII) helix. An unnatural amino acid termed a proline-templated glutamic acid (ptE) that constrained both the backbone and sidechain to the bound conformation was synthesized and incorporated into the pYTPXP peptide. We estimated imposing structural constraints onto the backbone and sidechain of the peptide and preorganize it to the bound conformation in solution will yield nearly an order of magnitude improvement in activity. NMR studies confirmed that the ptE-containing peptide adopts the PPII conformation, however, competitive binding studies showed an order of magnitude loss of activity. Given the emphasis that is placed on imposing structural constraints, we provide an example to support the contrary. These results point to conformational flexibility at the interface, which have implications in the design of potent Cbl(TKB)-binding peptides. PMID:23572190

  12. Functional design criteria W-367, 222-S ancillary equipment addition

    SciTech Connect

    McVey, C.B.

    1995-02-21

    This paper reviews the designs and performance of tubular solid oxide fuel cells (SOFCs). A large number of tubular cells of the porous support tube type have been electrically tested, some to times over 50,000 hours; these cells have shown excellent performance and performance stability. Since 1984, successfully larger electrical generators utilizing these cells have been built and operated; a 20 kW integrated SOFC system operated for 7064 hours during 1993-1994. Results of development efforts to reduce cost and increase power output of tubular cells by eliminating porous support tube and increasing active length are described, and plans to utilize such air electrode supported cells in future SOFC systems are discussed.

  13. Design of two-channel filter bank using nature inspired optimization based fractional derivative constraints.

    PubMed

    Kuldeep, B; Singh, V K; Kumar, A; Singh, G K

    2015-01-01

    In this article, a novel approach for 2-channel linear phase quadrature mirror filter (QMF) bank design based on a hybrid of gradient based optimization and optimization of fractional derivative constraints is introduced. For the purpose of this work, recently proposed nature inspired optimization techniques such as cuckoo search (CS), modified cuckoo search (MCS) and wind driven optimization (WDO) are explored for the design of QMF bank. 2-Channel QMF is also designed with particle swarm optimization (PSO) and artificial bee colony (ABC) nature inspired optimization techniques. The design problem is formulated in frequency domain as sum of L2 norm of error in passband, stopband and transition band at quadrature frequency. The contribution of this work is the novel hybrid combination of gradient based optimization (Lagrange multiplier method) and nature inspired optimization (CS, MCS, WDO, PSO and ABC) and its usage for optimizing the design problem. Performance of the proposed method is evaluated by passband error (ϕp), stopband error (ϕs), transition band error (ϕt), peak reconstruction error (PRE), stopband attenuation (As) and computational time. The design examples illustrate the ingenuity of the proposed method. Results are also compared with the other existing algorithms, and it was found that the proposed method gives best result in terms of peak reconstruction error and transition band error while it is comparable in terms of passband and stopband error. Results show that the proposed method is successful for both lower and higher order 2-channel QMF bank design. A comparative study of various nature inspired optimization techniques is also presented, and the study singles out CS as a best QMF optimization technique. PMID:25034647

  14. Decision making with epistemic uncertainty under safety constraints: An application to seismic design

    USGS Publications Warehouse

    Veneziano, D.; Agarwal, A.; Karaca, E.

    2009-01-01

    The problem of accounting for epistemic uncertainty in risk management decisions is conceptually straightforward, but is riddled with practical difficulties. Simple approximations are often used whereby future variations in epistemic uncertainty are ignored or worst-case scenarios are postulated. These strategies tend to produce sub-optimal decisions. We develop a general framework based on Bayesian decision theory and exemplify it for the case of seismic design of buildings. When temporal fluctuations of the epistemic uncertainties and regulatory safety constraints are included, the optimal level of seismic protection exceeds the normative level at the time of construction. Optimal Bayesian decisions do not depend on the aleatory or epistemic nature of the uncertainties, but only on the total (epistemic plus aleatory) uncertainty and how that total uncertainty varies randomly during the lifetime of the project. ?? 2009 Elsevier Ltd. All rights reserved.

  15. Design constraints for third-order PLL nodes in master-slave clock distribution networks

    NASA Astrophysics Data System (ADS)

    Bueno, A. M.; Rigon, A. G.; Ferreira, A. A.; Piqueira, José R. C.

    2010-09-01

    Clock signal distribution in telecommunication commercial systems usually adopts a master-slave architecture, with a precise time basis generator as a master and phase-locked loops (PLLs) as slaves. In the majority of the networks, second-order PLLs are adopted due to their simplicity and stability. Nevertheless, in some applications better transient responses are necessary and, consequently, greater order PLLs need to be used, in spite of the possibility of bifurcations and chaotic attractors. Here a master-slave network with third-order PLLs is analyzed and conditions for the stability of the synchronous state are derived, providing design constraints for the node parameters, in order to guarantee stability and reachability of the synchronous state for the whole network. Numerical simulations are carried out in order to confirm the analytical results.

  16. Synchronization controller design of two coupling permanent magnet synchronous motors system with nonlinear constraints.

    PubMed

    Deng, Zhenhua; Shang, Jing; Nian, Xiaohong

    2015-11-01

    In this paper, two coupling permanent magnet synchronous motors system with nonlinear constraints is studied. First of all, the mathematical model of the system is established according to the engineering practices, in which the dynamic model of motor and the nonlinear coupling effect between two motors are considered. In order to keep the two motors synchronization, a synchronization controller based on load observer is designed via cross-coupling idea and interval matrix. Moreover, speed, position and current signals of two motor all are taken as self-feedback signal as well as cross-feedback signal in the proposed controller, which is conducive to improving the dynamical performance and the synchronization performance of the system. The proposed control strategy is verified by simulation via Matlab/Simulink program. The simulation results show that the proposed control method has a better control performance, especially synchronization performance, than that of the conventional PI controller.

  17. The constraints satisfaction problem approach in the design of an architectural functional layout

    NASA Astrophysics Data System (ADS)

    Zawidzki, Machi; Tateyama, Kazuyoshi; Nishikawa, Ikuko

    2011-09-01

    A design support system with a new strategy for finding the optimal functional configurations of rooms for architectural layouts is presented. A set of configurations satisfying given constraints is generated and ranked according to multiple objectives. The method can be applied to problems in architectural practice, urban or graphic design-wherever allocation of related geometrical elements of known shape is optimized. Although the methodology is shown using simplified examples-a single story residential building with two apartments each having two rooms-the results resemble realistic functional layouts. One example of a practical size problem of a layout of three apartments with a total of 20 rooms is demonstrated, where the generated solution can be used as a base for a realistic architectural blueprint. The discretization of design space is discussed, followed by application of a backtrack search algorithm used for generating a set of potentially 'good' room configurations. Next the solutions are classified by a machine learning method (FFN) as 'proper' or 'improper' according to the internal communication criteria. Examples of interactive ranking of the 'proper' configurations according to multiple criteria and choosing 'the best' ones are presented. The proposed framework is general and universal-the criteria, parameters and weights can be individually defined by a user and the search algorithm can be adjusted to a specific problem.

  18. Explicit correlation model of multi-source constraints for Re-design parts with complex curved surface

    NASA Astrophysics Data System (ADS)

    Jia, Zhenyuan; Wang, Fuji; Wang, Yongqing; Guo, Dongming

    2014-03-01

    In precision machining of complex curved surface parts with high performance, geometry accuracy is not the only constraint, but the performance should also be met. Performance of this kind of parts is closely related to the geometrical and physical parameters, so the final actual size and shape are affected by multiple source constraints, such as geometry, physics, and performance. These parts are rather difficult to be manufactured and new manufacturing method according to performance requirement is urgently needed. Based on performance and manufacturing requirements for complex curved surface parts, a new classification method is proposed, which divided the complex curved surface parts into two categories: surface re-design complex curved surface parts with multi-source constraints(PRCS) and surface unique complex curved surface parts with pure geometric constraints(PUCS). A correlation model is constructed between the performance and multi-source constraints for PRCS, which reveals the correlation between the performance and multi-source constraints. A re-design method is also developed. Through solving the correlation model of the typical part's performance-associated surface, the mapping relation between the performance-associated surface and the related removal amount is obtained. The explicit correlation model and the method for the corresponding related removal amount of the performance-associated surface are built based on the classification of surface re-design complex curved surface parts with multi-source constraints. Research results have been used in the actual processing of the typical parts such as radome, common bottom components, nozzle, et al., which shows improved efficiency and accuracy of the precision machining for the surface re-design parts with complex curved surface.

  19. Multi Canister Overpack (MCO) Handling Machine Trolley Seismic Uplift Constraint Design Loads

    SciTech Connect

    SWENSON, C.E.

    2000-03-09

    The MCO Handling Machine (MHM) trolley moves along the top of the MHM bridge girders on east-west oriented rails. To prevent trolley wheel uplift during a seismic event, passive uplift constraints are provided as shown in Figure 1-1. North-south trolley wheel movement is prevented by flanges on the trolley wheels. When the MHM is positioned over a Multi-Canister Overpack (MCO) storage tube, east-west seismic restraints are activated to prevent trolley movement during MCO handling. The active seismic constraints consist of a plunger, which is inserted into slots positioned along the tracks as shown in Figure 1-1. When the MHM trolley is moving between storage tube positions, the active seismic restraints are not engaged. The MHM has been designed and analyzed in accordance with ASME NOG-1-1995. The ALSTHOM seismic analysis (Reference 3) reported seismic uplift restraint loading and EDERER performed corresponding structural calculations. The ALSTHOM and EDERER calculations were performed with the east-west seismic restraints activated and the uplift restraints experiencing only vertical loading. In support of development of the CSB Safety Analysis Report (SAR), an evaluation of the MHM seismic response was requested for the case where the east-west trolley restraints are not engaged. For this case, the associated trolley movements would result in east-west lateral loads on the uplift constraints due to friction, as shown in Figure 1-2. During preliminary evaluations, questions were raised as to whether the EDERER calculations considered the latest ALSTHOM seismic analysis loads (See NCR No. 00-SNFP-0008, Reference 5). Further evaluation led to the conclusion that the EDERER calculations used appropriate vertical loading, but the uplift restraints would need to be re-analyzed and modified to account for lateral loading. The disposition of NCR 00-SNFP-0008 will track the redesign and modification effort. The purpose of this calculation is to establish bounding seismic

  20. Multidisciplinary design optimization of a fighter aircraft with damage tolerance constraints and a probabilistic model of the fatigue environment

    NASA Astrophysics Data System (ADS)

    Arrieta, Albert Joseph

    2001-07-01

    Damage tolerance analysis (DTA) was considered in the global design optimization of an aircraft wing structure. Residual strength and fatigue life requirements, based on the damage tolerance philosophy, were investigated as new design constraints. In general, accurate fatigue prediction is difficult if the load environment is not known with a high degree of certainty. To address this issue, a probabilistic approach was used to describe the uncertain load environment. Probabilistic load spectra models were developed from flight recorder data. The global/local finite element approach allowed local fatigue requirements to be considered in the global design optimization. AFGROW fatigue crack growth analysis provided a new strength criterion for satisfying damage tolerance requirements within a global optimization environment. Initial research with the ASTROS program used the probabilistic load model and this damage tolerance constraint to optimize cracked skin panels on the lower wing of a fighter/attack aircraft. For an aerodynamic and structural model similar to an F-16, ASTROS simulated symmetric and asymmetric maneuvers during the optimization. Symmetric maneuvers, without underwing stores, produced the highest stresses and drove the optimization of the inboard lower wing skin. Asymmetric maneuvers, with underwing stores, affected the optimum thickness of the outboard hard points. Subsequent design optimizations included von Mises stress, aileron effectiveness, and lift effectiveness constraints simultaneously. This optimization was driven by the DTA and von Mises stress constraints and, therefore, DTA requirements can have an active role to play in preliminary aircraft design.

  1. Constraints on target chamber first wall and target designs that will enable NIF debris shields to survive

    NASA Astrophysics Data System (ADS)

    Burnham, Alan K.; Gerassimenko, Michel; Scott, J. M.; Latkowski, Jeff F.; Whitman, Pamela K.; Genin, Francois Y.; Hibbard, Wilthea; Peterson, P. F.; Tokheim, R. E.; Curran, D. R.

    1999-07-01

    The NIF target chamber interior materials and target designs themselves have to be compatible with survival of the final- optics debris shields. To meet the planned maintenance and refinishing rate, the contamination of the debris shields cannot exceed about 1 nm equivalent thickness per shot of total material. This implies that he target mass must be limited to no more than 1 gram and the ablated mass released to the chamber from all other components must not exceed 3 grams. In addition, the targets themselves must either completely vaporize or send any minor amounts of shrapnel towards the chamber waist to prevent excessive catering of the debris shields. The constraints on the first-wall debris will remobilize at a rate fast enough to require cleaning every 3 weeks, about three times more frequent than possible with planned robotics. Furthermore, a comparison of ablatants from B4C and stainless-steel louvers suggest that remobilization of target debris by x-rays will be greater than that of the base material in both cases, thereby reducing the performance advantage of clean B4C over much cheaper stainless steel. Neutronics calculations indicate that activation of thin Ni-free stainless steel is not a significant source of maintenance personnel radiation dose. Consequently, the most attractive first wall design consists of stainless-steel louvers. Evaluation of various unconverted-light beam dump designs indicates that stainless steel louvers generate no more debris than other matrices, so one single design can serve as both first wall and beam dumps, eliminating beam steering restrictions caused by size and location of the beam dumps. One reservation is that the allowable contamination rate of the debris shield is not yet completely understood. Consequently, it is likely that either a protruding beam tube, a rapid post-shot gas purge of the final optics assembly, or thin polymeric pre-shield will be required to prevent low-velocity contamination from reaching

  2. RNAiFold2T: Constraint Programming design of thermo-IRES switches

    PubMed Central

    Garcia-Martin, Juan Antonio; Dotu, Ivan; Fernandez-Chamorro, Javier; Lozano, Gloria; Ramajo, Jorge; Martinez-Salas, Encarnacion; Clote, Peter

    2016-01-01

    Motivation: RNA thermometers (RNATs) are cis-regulatory elements that change secondary structure upon temperature shift. Often involved in the regulation of heat shock, cold shock and virulence genes, RNATs constitute an interesting potential resource in synthetic biology, where engineered RNATs could prove to be useful tools in biosensors and conditional gene regulation. Results: Solving the 2-temperature inverse folding problem is critical for RNAT engineering. Here we introduce RNAiFold2T, the first Constraint Programming (CP) and Large Neighborhood Search (LNS) algorithms to solve this problem. Benchmarking tests of RNAiFold2T against existent programs (adaptive walk and genetic algorithm) inverse folding show that our software generates two orders of magnitude more solutions, thus allowing ample exploration of the space of solutions. Subsequently, solutions can be prioritized by computing various measures, including probability of target structure in the ensemble, melting temperature, etc. Using this strategy, we rationally designed two thermosensor internal ribosome entry site (thermo-IRES) elements, whose normalized cap-independent translation efficiency is approximately 50% greater at 42 °C than 30 °C, when tested in reticulocyte lysates. Translation efficiency is lower than that of the wild-type IRES element, which on the other hand is fully resistant to temperature shift-up. This appears to be the first purely computational design of functional RNA thermoswitches, and certainly the first purely computational design of functional thermo-IRES elements. Availability: RNAiFold2T is publicly available as part of the new release RNAiFold3.0 at https://github.com/clotelab/RNAiFold and http://bioinformatics.bc.edu/clotelab/RNAiFold, which latter has a web server as well. The software is written in C ++ and uses OR-Tools CP search engine. Contact: clote@bc.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID

  3. Disassemblability modeling technology of configurable product based on disassembly constraint relation weighted design structure matrix(DSM)

    NASA Astrophysics Data System (ADS)

    Qiu, Lemiao; Liu, Xiaojian; Zhang, Shuyou; Sun, Liangfeng

    2014-05-01

    The current research of configurable product disassemblability focuses on disassemblability evaluation and disassembly sequence planning. Little work has been done on quantitative analysis of configurable product disassemblability. The disassemblability modeling technology for configurable product based on disassembly constraint relation weighted design structure matrix (DSM) is proposed. Major factors affecting the disassemblability of configurable product are analyzed, and the disassembling degrees between components in configurable product are obtained by calculating disassembly entropies such as joint type, joint quantity, disassembly path, disassembly accessibility and material compatibility. The disassembly constraint relation weighted DSM of configurable product is constructed and configuration modules are formed by matrix decomposition and tearing operations. The disassembly constraint relation in configuration modules is strong coupling, and the disassembly constraint relation between modules is weak coupling, and the disassemblability configuration model is constructed based on configuration module. Finally, taking a hydraulic forging press as an example, the decomposed weak coupling components are used as configuration modules alone, components with a strong coupling are aggregated into configuration modules, and the disassembly sequence of components inside configuration modules is optimized by tearing operation. A disassemblability configuration model of the hydraulic forging press is constructed. By researching the disassemblability modeling technology of product configuration design based on disassembly constraint relation weighted DSM, the disassembly property in maintenance, recycling and reuse of configurable product are optimized.

  4. Design of optimal groundwater remediation systems under flexible environmental-standard constraints.

    PubMed

    Fan, Xing; He, Li; Lu, Hong-Wei; Li, Jing

    2015-01-01

    In developing optimal groundwater remediation strategies, limited effort has been exerted to solve the uncertainty in environmental quality standards. When such uncertainty is not considered, either over optimistic or over pessimistic optimization strategies may be developed, probably leading to the formulation of rigid remediation strategies. This study advances a mathematical programming modeling approach for optimizing groundwater remediation design. This approach not only prevents the formulation of over optimistic and over pessimistic optimization strategies but also provides a satisfaction level that indicates the degree to which the environmental quality standard is satisfied. Therefore the approach may be expected to be significantly more acknowledged by the decision maker than those who do not consider standard uncertainty. The proposed approach is applied to a petroleum-contaminated site in western Canada. Results from the case study show that (1) the peak benzene concentrations can always satisfy the environmental standard under the optimal strategy, (2) the pumping rates of all wells decrease under a relaxed standard or long-term remediation approach, (3) the pumping rates are less affected by environmental quality constraints under short-term remediation, and (4) increased flexible environmental standards have a reduced effect on the optimal remediation strategy.

  5. Mathematical extrapolation of image spectrum for constraint-set design and set-theoretic superresolution.

    PubMed

    Bhattacharjee, Supratik; Sundareshan, Malur K

    2003-08-01

    Several powerful iterative algorithms are being developed for the restoration and superresolution of diffraction-limited imagery data by use of diverse mathematical techniques. Notwithstanding the mathematical sophistication of the approaches used in their development and the potential for resolution enhancement possible with their implementation, the spectrum extrapolation that is central to superresolution comes in these algorithms only as a by-product and needs to be checked only after the completion of the processing steps to ensure that an expansion of the image bandwidth has indeed occurred. To overcome this limitation, a new approach of mathematically extrapolating the image spectrum and employing it to design constraint sets for implementing set-theoretic estimation procedures is described. Performance evaluation of a specific projection-onto-convex-sets algorithm by using this approach for the restoration and superresolution of degraded images is outlined. The primary goal of the method presented is to expand the power spectrum of the input image beyond the range of the sensor that captured the image.

  6. Constrictor: Flux Balance Analysis Constraint Modification Provides Insight for Design of Biochemical Networks

    NASA Astrophysics Data System (ADS)

    Erickson, Keesha; Chatterjee, Anushree

    2014-03-01

    The use of in silico methods has become standard practice to correlate the structure of a biochemical network to the expression of a desired phenotype. Flux balance analysis (FBA) is one of the most prevalent techniques for modeling metabolism. FBA models have been successfully applied to obtain growth predictions, theoretical product yields from heterologous pathways, and genome engineering targets. We take inspiration from high-throughput recombineering techniques, which show that combinatorial exploration can reveal optimal mutants, and apply the advantages of computational techniques to analyze these combinations. We introduce Constrictor, an in silico tool for FBA that allows gene mutations to be analyzed in a combinatorial fashion, by applying simulated constraints accounting for regulation of gene expression. We apply this algorithm to study ethylene production in E. coli through the addition of the heterologous ethylene-forming enzyme from P. syringae. Targeting individual reactions as well as sets of reactions results in theoretical ethylene yields that are as much 65% greater than yields calculated using typical FBA. Constrictor is an adaptable technique that can be used to generate and analyze disparate populations of in silico mutants & select gene expression levels.

  7. 77 FR 9251 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-16

    ... designate a class of employees from the Linde Ceramics Plant in Tonawanda, New York, as an addition to the... addition to the SEC: All Atomic Weapons Employees who worked in any area at the Linde Ceramics Plant...

  8. 13 CFR 108.1940 - Procedures for designation of additional Low-Income Geographic Areas

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...) as LI Areas. (b) Criteria. SBA will consider one or more of the following factors in determining whether to designate a particular census tract (or equivalent county division) as an additional LI Area... designation of an additional LI Area, SBA will publish in the Federal Register a notice that it is...

  9. 76 FR 51035 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-17

    ... HUMAN SERVICES Designation of a Class of Employees for Addition to the Special Exposure Cohort AGENCY...). ACTION: Notice. SUMMARY: HHS gives notice of a decision to designate a class of employees from Sandia National Laboratories in Albuquerque, New Mexico, as an addition to the Special Exposure Cohort (SEC)...

  10. 77 FR 32640 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-01

    ... designate a class of employees from Sandia National Laboratories in Albuquerque, New Mexico, as an addition to the Special Exposure Cohort (SEC) under the Energy Employees Occupational Illness Compensation... HUMAN SERVICES Designation of a Class of Employees for Addition to the Special Exposure Cohort...

  11. 77 FR 32641 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-01

    ... designate a class of employees from the Brookhaven National Laboratory in Upton, New York, as an addition to the Special Exposure Cohort (SEC) under the Energy Employees Occupational Illness Compensation Program... HUMAN SERVICES Designation of a Class of Employees for Addition to the Special Exposure Cohort...

  12. Tilable nature of virus capsids and the role of topological constraints in natural capsid design

    NASA Astrophysics Data System (ADS)

    Mannige, Ranjan V.; Brooks, Charles L., III

    2008-05-01

    Virus capsids are highly specific assemblies that are formed from a large number of often chemically identical capsid subunits. In the present paper we ask to what extent these structures can be viewed as mathematically tilable objects using a single two-dimensional tile. We find that spherical viruses from a large number of families—eight out of the twelve studied—qualitatively possess properties that allow their representation as two-dimensional monohedral tilings of a bound surface, where each tile represents a subunit. This we did by characterizing the extent to which individual spherical capsids display subunit-subunit (1) holes, (2) overlaps, and (3) gross structural variability. All capsids with T numbers greater than 1 from the Protein Data Bank, with homogeneous protein composition, were used in the study. These monohedral tilings, called canonical capsids due to their platonic (mathematical) form, offer a mathematical segue into the structural and dynamical understanding of not one, but a large number of virus capsids. From our data, it appears as though one may only break the long-standing rules of quasiequivalence by the introduction of subunit-subunit structural variability, holes, and gross overlaps into the shell. To explore the utility of canonical capsids in understanding structural aspects of such assemblies, we used graph theory and discrete geometry to enumerate the types of shapes that the tiles (and hence the subunits) must possess. We show that topology restricts the shape of the face to a limited number of five-sided prototiles, one of which is the “bisected trapezoid” that is a platonic representation of the most ubiquitous capsid subunit shape seen in nature (the trapezoidal jelly-roll motif). This motif is found in a majority of seemingly unrelated virus families that share little to no host, size, or amino acid sequence similarity. This suggests that topological constraints may exhibit dominant roles in the natural design of

  13. 75 FR 22410 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-28

    ... Livermore National Laboratory in Livermore, California, as an addition to the Special Exposure Cohort (SEC... Secretary of HHS designated the following class of employees as an addition to the SEC: All employees of the... publish a notice in the Federal Register reporting the addition of this class to the SEC or the result...

  14. 76 FR 68460 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-04

    ... Laboratory at Iowa State University as an addition to the Special Exposure Cohort (SEC) under the Energy... designated the following class of employees as an addition to the SEC: All Department of Energy (DOE... will publish a notice in the Federal Register reporting the addition of this class to the SEC or...

  15. 75 FR 22409 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-28

    ... the Santa Susana Field Laboratory as an addition to the Special Exposure Cohort (SEC) under the Energy... designated the following class of employees as an addition to the SEC: All employees of the Department of... notice in the Federal Register reporting the addition of this class to the SEC or the result of...

  16. 76 FR 68459 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-04

    ... facility in Oak Ridge, Tennessee, as an addition to the Special Exposure Cohort (SEC) under the Energy... designated the following class of employees as an addition to the SEC: All employees of the Department of... publish a notice in the Federal Register reporting the addition of this class to the SEC or the result...

  17. 75 FR 22409 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-28

    ... Berkeley National Laboratory in Berkeley, California, as an addition to the Special Exposure Cohort (SEC... Secretary of HHS designated the following class of employees as an addition to the SEC: All employees of the... will publish a notice in the Federal Register reporting the addition of this class to the SEC or...

  18. Modified constraint-induced movement therapy for clients with chronic stroke: interrupted time series (ITS) design.

    PubMed

    Park, JuHyung; Lee, NaYun; Cho, YongHo; Yang, YeongAe

    2015-03-01

    [Purpose] The purpose of this study was to investigate the impact that modified constraint-induced movement therapy has on upper extremity function and the daily life of chronic stroke patients. [Subjects and Methods] Modified constraint-induced movement therapy was conduct for 2 stroke patients with hemiplegia. It was performed 5 days a week for 2 weeks, and the participants performed their daily living activities wearing mittens for 6 hours a day, including the 2 hours of the therapy program. The assessment was conducted 5 times in 3 weeks before and after intervention. The upper extremity function was measured using the box and block test and a dynamometer, and performance daily of living activities was assessed using the modified Barthel index. The results were analyzed using a scatterplot and linear regression. [Results] All the upper extremity functions of the participants all improved after the modified constraint-induced movement therapy. Performance of daily living activities by participant 1 showed no change, but the results of participant 2 had improved after the intervention. [Conclusion] Through the results of this research, it was identified that modified constraint-induced movement therapy is effective at improving the upper extremity functions and the performance of daily living activities of chronic stroke patients.

  19. Modified constraint-induced movement therapy for clients with chronic stroke: interrupted time series (ITS) design

    PubMed Central

    Park, JuHyung; Lee, NaYun; Cho, YongHo; Yang, YeongAe

    2015-01-01

    [Purpose] The purpose of this study was to investigate the impact that modified constraint-induced movement therapy has on upper extremity function and the daily life of chronic stroke patients. [Subjects and Methods] Modified constraint-induced movement therapy was conduct for 2 stroke patients with hemiplegia. It was performed 5 days a week for 2 weeks, and the participants performed their daily living activities wearing mittens for 6 hours a day, including the 2 hours of the therapy program. The assessment was conducted 5 times in 3 weeks before and after intervention. The upper extremity function was measured using the box and block test and a dynamometer, and performance daily of living activities was assessed using the modified Barthel index. The results were analyzed using a scatterplot and linear regression. [Results] All the upper extremity functions of the participants all improved after the modified constraint-induced movement therapy. Performance of daily living activities by participant 1 showed no change, but the results of participant 2 had improved after the intervention. [Conclusion] Through the results of this research, it was identified that modified constraint-induced movement therapy is effective at improving the upper extremity functions and the performance of daily living activities of chronic stroke patients. PMID:25931770

  20. Method for the optimal dimensional synthesis of multibody systems with dynamic constraints. Application to planar mechanisms design

    NASA Astrophysics Data System (ADS)

    Gomez Cristobal, Jose Antonio

    The thesis presents a method for the optimal dimensional synthesis of multibody systems with topological, geometric, position, kinematic and dynamic constraints. The method is based on the minimization of an elastic potential energy objective function whose design variables are natural coordinates and bar lengths of the system with a system modelling similar to that used in the finite elements method. The optimisation is performed by means of a sequential quadratic programming algorithm implemented through routine E04UCF of the mathematical library NAG. The resulting method can be applied to multibody systems composed of rigid bodies, irrespective of the dimension of their movement, geometric configuration and kinematic pairs of the kinematic chain, and allows for the mobility of fixed points. Using previous developments to resolve velocity and acceleration kinematic problems, the equations systems of the multibody system dynamic equilibrium and their partial derivatives with respect to the designing variables are analytically solved. The resolution of these equations systems provides analytical expressions of the dynamic problem parameters that can be imposed as restrictions in the designing phase, and well as their Jacobians. The Hessians, which are also required by the sequential quadratic programming algorithm, are calculated from the analytical expressions of the dynamic parameters and Jacobians following the numerical method of finite differences. The expressions for the dynamic constraints of input and output forces, constraint forces, support reactions, mass of bodies, as well as the main merit indexes---ratio of angular velocities, mechanical advantage and transmission angle---are developed. These expressions are subsequently used to optimise the dynamic behaviour of planar mechanisms. The described method enables the simultaneous optimisation of the kinematic and dynamic behaviour of the system from the very earliest phases of design, thus making design

  1. Additive genetic variation in resistance traits of an exotic pine species: little evidence for constraints on evolution of resistance against native herbivores

    PubMed Central

    Moreira, X; Zas, R; Sampedro, L

    2013-01-01

    The apparent failure of invasions by alien pines in Europe has been explained by the co-occurrence of native pine congeners supporting herbivores that might easily recognize the new plants as hosts. Previous studies have reported that exotic pines show reduced tolerance and capacity to induce resistance to those native herbivores. We hypothesize that limited genetic variation in resistance to native herbivores and the existence of evolutionary trade-offs between growth and resistance could represent additional potential constraints on the evolution of invasiveness of exotic pines outside their natural range. In this paper, we examined genetic variation for constitutive and induced chemical defences (measured as non-volatile resin in the stem and total phenolics in the needles) and resistance to two major native generalist herbivores of pines in cafeteria bioassays (the phloem-feeder Hylobius abietis and the defoliator Thaumetopoea pityocampa) using half-sib families drawn from a sample of the population of Pinus radiata introduced to Spain in the mid-19th century. We found (i) significant genetic variation, with moderate-to-high narrow-sense heritabilities for both the production of constitutive non-volatile resin and induced total phenolics, and for constitutive resistance against T. pityocampa in bioassays, (ii) no evolutionary trade-offs between plant resistance and growth traits or between the production of different quantitative chemical defences and (iii) a positive genetic correlation between constitutive resistance to the two studied herbivores. Overall, results of our study indicate that the exotic pine P. radiata has limited genetic constraints on the evolution of resistance against herbivores in its introduced range, suggesting that, at least in terms of interactions with these enemies, this pine species has potential to become invasive in the future. PMID:23232833

  2. 77 FR 9250 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-16

    ... designate a class of employees from the Savannah River Site in Aiken, South Carolina, as an addition to the... contractors and subcontractors who worked at the Savannah River Site from January 1, 1953, through...

  3. 77 FR 76489 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-28

    ... designate a class of employees from the Mound Plant in Miamisburg, Ohio, as an addition to the Special... subcontractors who worked at the Mound Plant in Miamisburg, Ohio, from September 1, 1972, through December...

  4. Wood lens design philosophy based on a binary additive manufacturing technique

    NASA Astrophysics Data System (ADS)

    Marasco, Peter L.; Bailey, Christopher

    2016-04-01

    Using additive manufacturing techniques in optical engineering to construct a gradient index (GRIN) optic may overcome a number of limitations of GRIN technology. Such techniques are maturing quickly, yielding additional design degrees of freedom for the engineer. How best to employ these degrees of freedom is not completely clear at this time. This paper describes a preliminary design philosophy, including assumptions, pertaining to a particular printing technique for GRIN optics. It includes an analysis based on simulation and initial component measurement.

  5. 76 FR 63351 - Designation of Additional Individual Pursuant to Executive Order 13413

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-12

    ... Office of Foreign Assets Control Designation of Additional Individual Pursuant to Executive Order 13413... Office of Foreign Assets Control (``OFAC'') is publishing the name of one individual whose property and... designation by the Director of OFAC of the individual identified in this notice, pursuant to Executive...

  6. 76 FR 76219 - Designation of Additional Individual Pursuant to Executive Order 13413

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-06

    ... Office of Foreign Assets Control Designation of Additional Individual Pursuant to Executive Order 13413... Office of Foreign Assets Control (``OFAC'') is publishing the name of one individual whose property and... designation by the Director of OFAC of the individual identified in this notice, pursuant to Executive...

  7. 75 FR 22410 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-28

    ... Employer employees who worked at Westinghouse Electric Corp., Bloomfield, New Jersey, from August 13, 1942... HUMAN SERVICES Designation of a Class of Employees for Addition to the Special Exposure Cohort AGENCY...). ACTION: Notice. SUMMARY: HHS gives notice of a decision to designate a class of employees at...

  8. STEADY-STATE DESIGN OF VERTICAL WELLS FOR LIQUIDS ADDITION AT BIOREACTOR LANDFILLS

    EPA Science Inventory

    This paper presents design charts that a landfill engineer can use for the design of a vertical well system for liquids addition at bioreactor landfills. The flow rate and lateral and vertical zones of impact of a vertical well were estimated as a function of input variables su...

  9. 75 FR 22410 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-28

    ... Test Site as an addition to the Special Exposure Cohort (SEC) under the Energy Employees Occupational... class of employees as an addition to the SEC: All employees of the Department of Energy, its predecessor... or more other classes of employees in the SEC. This designation will become effective on May 5,...

  10. 77 FR 2545 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-18

    ... Plant in Amarillo, Texas, as an addition to the Special Exposure Cohort (SEC) under the Energy Employees... the following class of employees as an addition to the SEC: All employees of the Department of Energy... included in the SEC. This designation will become effective on January 20, 2012 unless Congress...

  11. Reversible competitive α-ketoheterocycle inhibitors of fatty acid amide hydrolase containing additional conformational constraints in the acyl side chain: orally active, long-acting analgesics.

    PubMed

    Ezzili, Cyrine; Mileni, Mauro; McGlinchey, Nicholas; Long, Jonathan Z; Kinsey, Steven G; Hochstatter, Dustin G; Stevens, Raymond C; Lichtman, Aron H; Cravatt, Benjamin F; Bilsky, Edward J; Boger, Dale L

    2011-04-28

    A series of α-ketooxazoles containing conformational constraints in the C2 acyl side chain of 2 (OL-135) were examined as inhibitors of fatty acid amide hydrolase (FAAH). Only one of the two possible enantiomers displayed potent FAAH inhibition (S vs R enantiomer), and their potency is comparable or improved relative to 2, indicating that the conformational restriction in the C2 acyl side chain is achievable. A cocrystal X-ray structure of the α-ketoheterocycle 12 bound to a humanized variant of rat FAAH revealed its binding details, confirmed that the (S)-enantiomer is the bound active inhibitor, shed light on the origin of the enantiomeric selectivity, and confirmed that the catalytic Ser241 is covalently bound to the electrophilic carbonyl as a deprotonated hemiketal. Preliminary in vivo characterization of the inhibitors 12 and 14 is reported demonstrating that they raise brain anandamide levels following either intraperitoneal (ip) or oral (po) administration indicative of effective in vivo FAAH inhibition. Significantly, the oral administration of 12 caused dramatic accumulation of anandamide in the brain, with peak levels achieved between 1.5 and 3 h, and these elevations were maintained over 9 h. Additional studies of these two representative members of the series (12 and 14) in models of thermal hyperalgesia and neuropathic pain are reported, including the demonstration that 12 administered orally significantly attenuated mechanical (>6 h) and cold (>9 h) allodynia for sustained periods consistent with its long-acting effects in raising the endogenous concentration of anandamide.

  12. Improvement in protein functional site prediction by distinguishing structural and functional constraints on protein family evolution using computational design.

    PubMed

    Cheng, Gong; Qian, Bin; Samudrala, Ram; Baker, David

    2005-01-01

    The prediction of functional sites in newly solved protein structures is a challenge for computational structural biology. Most methods for approaching this problem use evolutionary conservation as the primary indicator of the location of functional sites. However, sequence conservation reflects not only evolutionary selection at functional sites to maintain protein function, but also selection throughout the protein to maintain the stability of the folded state. To disentangle sequence conservation due to protein functional constraints from sequence conservation due to protein structural constraints, we use all atom computational protein design methodology to predict sequence profiles expected under solely structural constraints, and to compute the free energy difference between the naturally occurring amino acid and the lowest free energy amino acid at each position. We show that functional sites are more likely than non-functional sites to have computed sequence profiles which differ significantly from the naturally occurring sequence profiles and to have residues with sub-optimal free energies, and that incorporation of these two measures improves sequence based prediction of protein functional sites. The combined sequence and structure based functional site prediction method has been implemented in a publicly available web server.

  13. Design Constraints Regarding The Use Of Fluids In Emergency Medical Systems For Space Flight

    NASA Technical Reports Server (NTRS)

    McQuillen, John

    2013-01-01

    The Exploration Medical Capability Project of the Human Research Program is tasked with identifying, investigating and addressing gaps existing gaps in either knowledge or technology that need to be addressed in order to enable safer exploration missions. There are several gaps that involve treatment for emergency medical situations. Some of these treatments involve the handling of liquids in the spacecraft environment which involve gas-liquid mixtures handling, dissolution chemistry and thermal issues. Some of the recent technology efforts include the Intravenous fluid generation (IVGEN) experiment, the In-Suit Injection System (ISIS) experiment, and medical suction. Constraints include limited volume, shelf life, handling biohazards, availability of power, crew time and medical training.

  14. Spatial, socio-economic, and ecological implications of incorporating minimum size constraints in marine protected area network design.

    PubMed

    Metcalfe, Kristian; Vaughan, Gregory; Vaz, Sandrine; Smith, Robert J

    2015-12-01

    Marine protected areas (MPAs) are the cornerstone of most marine conservation strategies, but the effectiveness of each one partly depends on its size and distance to other MPAs in a network. Despite this, current recommendations on ideal MPA size and spacing vary widely, and data are lacking on how these constraints might influence the overall spatial characteristics, socio-economic impacts, and connectivity of the resultant MPA networks. To address this problem, we tested the impact of applying different MPA size constraints in English waters. We used the Marxan spatial prioritization software to identify a network of MPAs that met conservation feature targets, whilst minimizing impacts on fisheries; modified the Marxan outputs with the MinPatch software to ensure each MPA met a minimum size; and used existing data on the dispersal distances of a range of species found in English waters to investigate the likely impacts of such spatial constraints on the region's biodiversity. Increasing MPA size had little effect on total network area or the location of priority areas, but as MPA size increased, fishing opportunity cost to stakeholders increased. In addition, as MPA size increased, the number of closely connected sets of MPAs in networks and the average distance between neighboring MPAs decreased, which consequently increased the proportion of the planning region that was isolated from all MPAs. These results suggest networks containing large MPAs would be more viable for the majority of the region's species that have small dispersal distances, but dispersal between MPA sets and spill-over of individuals into unprotected areas would be reduced. These findings highlight the importance of testing the impact of applying different MPA size constraints because there are clear trade-offs that result from the interaction of size, number, and distribution of MPAs in a network.

  15. Design under Constraints: The Case of Large-Scale Assessment Systems

    ERIC Educational Resources Information Center

    Mislevy, Robert J.

    2010-01-01

    In "Updating the Duplex Design for Test-Based Accountability in the Twenty-First Century," Bejar and Graf (2010) propose extensions to the duplex design for large-scale assessment presented in Bock and Mislevy (1988). Examining the range of people who use assessment results--from students, teachers, administrators, curriculum designers,…

  16. 49 CFR 173.412 - Additional design requirements for Type A packages.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Additional design requirements for Type A packages. 173.412 Section 173.412 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SHIPPERS-GENERAL REQUIREMENTS FOR SHIPMENTS...

  17. 78 FR 50313 - Final Additional Airworthiness Design Standards: Night Visual Flight Rules (VFR) Under the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-19

    ... Code of Federal Regulations and two additional design criteria issued on September 2, 2003 (68 FR 56809... Federal Register on Friday May 31, 2013, 78 FR 32576. No comments were received, and the airworthiness... extremes, rain, fuel, oil, and solvents to which it is expected to be exposed in service and...

  18. 47 CFR 54.202 - Additional requirements for Commission designation of eligible telecommunications carriers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 3 2014-10-01 2014-10-01 false Additional requirements for Commission designation of eligible telecommunications carriers. 54.202 Section 54.202 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES (CONTINUED) UNIVERSAL SERVICE Carriers Eligible for Universal Service Support §...

  19. 78 FR 148 - Additional Designations of Individuals Pursuant to Executive Order 13581

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-02

    ... Office of Foreign Assets Control Additional Designations of Individuals Pursuant to Executive Order 13581... Treasury's Office of Foreign Assets Control (``OFAC'') is publishing the names of three individuals whose... Director of OFAC of the five individuals identified in this notice pursuant to Executive Order 13581...

  20. 77 FR 54946 - Additional Designations of Individuals Pursuant to Executive Order 13581

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-06

    ... Office of Foreign Assets Control Additional Designations of Individuals Pursuant to Executive Order 13581... Treasury 's Office of Foreign Assets Control (``OFAC'') is publishing the names of five individuals whose... Director of OFAC of the five individuals identified in this notice pursuant to Executive Order 13581...

  1. 77 FR 54946 - Additional Designations of Individuals Pursuant to Executive Order 13581

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-06

    ... Office of Foreign Assets Control Additional Designations of Individuals Pursuant to Executive Order 13581... Treasury's Office of Foreign Assets Control (``OFAC'') is publishing the names of five individuals whose... Director of OFAC of the five individuals identified in this notice pursuant to Executive Order 13581...

  2. 47 CFR 54.202 - Additional requirements for Commission designation of eligible telecommunications carriers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES (CONTINUED) UNIVERSAL SERVICE Carriers Eligible for Universal Service Support § 54.202 Additional requirements for Commission designation of eligible... government and tribal regulatory authority, as applicable, at the time it files its petition with the...

  3. 47 CFR 54.202 - Additional requirements for Commission designation of eligible telecommunications carriers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES (CONTINUED) UNIVERSAL SERVICE Carriers Eligible for Universal Service Support § 54.202 Additional requirements for Commission designation of eligible... government and tribal regulatory authority, as applicable, at the time it files its petition with the...

  4. 77 FR 40059 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-06

    ... HUMAN SERVICES Designation of a Class of Employees for Addition to the Special Exposure Cohort AGENCY..., Department of Health and Human Services (HHS). ACTION: Notice. SUMMARY: HHS gives notice of a decision to... (SEC) under the Energy Employees Occupational Illness Compensation Program Act of 2000. On June...

  5. 76 FR 28436 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-17

    ... HUMAN SERVICES Designation of a Class of Employees for Addition to the Special Exposure Cohort AGENCY: National Institute for Occupational Safety and Health (NIOSH), Department of Health and Human Services (HHS...) under the Energy Employees Occupational Illness Compensation Program Act of 2000. On April 29, 2011,...

  6. 77 FR 32640 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-01

    ... HUMAN SERVICES Designation of a Class of Employees for Addition to the Special Exposure Cohort AGENCY..., Department of Health and Human Services (HHS). ACTION: Notice. SUMMARY: HHS gives notice of a decision to... the Special Exposure Cohort (SEC) under the Energy Employees Occupational Illness Compensation...

  7. 76 FR 28436 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-17

    ... Cohort (SEC) under the Energy Employees Occupational Illness Compensation Program Act of 2000. On April 29, 2011, the Secretary of HHS designated the following class of employees as an addition to the SEC... the SEC or the result of any provision by Congress regarding the decision by HHS to add the class...

  8. 78 FR 54791 - Proposed Additional Airworthiness Design Standards: Advanced Avionics Under the Special Class...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-06

    ... Regulations and two additional design criteria issued on September 2, 2003 (68 FR 56809). The regulation... 75 FR 32576. In conjunction with the expansion to Night-VFR operations intergrated avionic displays...: Advanced Avionics Under the Special Class (JAR-VLA) Regulations; Aquila Aviation by Excellence GmbH,...

  9. Earth Shelter Buildings Coupled with the Sun: Opportunities and Constraints in Design.

    ERIC Educational Resources Information Center

    Bennett, David J.

    1982-01-01

    The new Civil/Mineral Engineering Building on the University of Minnesota Minneapolis campus is a demonstration design in energy conservation and innovation in active and passive solar energy applications. Its antecedents at the university represent contributory steps in the identification of issues and the development of design principles. (MLW)

  10. Using "Constraints" to Design Developmentally Appropriate Movement Activities for Early Childhood Education

    ERIC Educational Resources Information Center

    Gagen, Linda M.; Getchell, Nancy

    2006-01-01

    Teachers of young children know the importance of designing developmentally appropriate activities to encourage motor development but are not always prepared with the information they need to accomplish this design. When teachers choose movement activities, motor development theory must be understood and utilized in the planning of activities to…

  11. Automated structural design with aeroelastic constraints - A review and assessment of the state of the art

    NASA Technical Reports Server (NTRS)

    Stroud, W. J.

    1974-01-01

    A review and assessment of the state of the art in automated aeroelastic design is presented. Most of the aeroelastic design studies appearing in the literature deal with flutter, and, therefore, this paper also concentrates on flutter. The flutter design problem is divided into three cases: as isolated flutter mode, neighboring flutter modes, and a hump mode which can rise and cause a sudden, discontinuous change in the flutter velocity. Synthesis procedures are presented in terms of techniques that are appropriate for problems of various levels of difficulty. Current trends, which should result in more efficient, powerful and versatile design codes, are discussed. Approximate analysis procedures and the need for simultaneous consideration of multiple design requirements are emphasized.

  12. Design and Evaluation of the User-Adapted Program Scheduling system based on Bayesian Network and Constraint Satisfaction

    NASA Astrophysics Data System (ADS)

    Iwasaki, Hirotoshi; Sega, Shinichiro; Hiraishi, Hironori; Mizoguchi, Fumio

    In recent years, lots of music content can be stored in mobile computing devices, such as a portable digital music player and a car navigation system. Moreover, various information content like news or traffic information can be acquired always anywhere by a cellular communication and a wireless LAN. However, usability issues arise from the simple interfaces of mobile computing devices. Moreover, retrieving and selecting such content poses safety issues, especially while driving. Thus, it is important for the mobile system to recommend content automatically adapted to user's preference and situation. In this paper, we present the user-adapted program scheduling that generates sequences of content (Program) suiting user's preference and situation based on the Bayesian network and the Constraint Satisfaction Problem (CSP) technique. We also describe the design and evaluation of its realization system, the Personal Program Producer (P3). First, preference such as a genre ratio of content in a program is learned as a Bayesian network model using simple operations such as a skip behavior. A model including each content tends to become large-scale. In order to make it small, we present the model separation method that carries out losslessly compression of the model. Using the model, probabilistic distributions of preference to generate constraints are inferred. Finally satisfying the constraints, a program is produced. This kind of CSP has an issue of which the number of variables is not fixedness. In order to make it variable, we propose a method using metavariables. To evaluate the above methods, we applied them to P3 on a car navigation system. User evaluations helped us clarify that the P3 can produce the program that a user prefers and adapt it to the user.

  13. An entomologist guide to demystify pseudoreplication: data analysis of field studies with design constraints.

    PubMed

    Chaves, Luis Fernando

    2010-05-01

    Lack of independence, or pseudoreplication, in samples from ecological studies of insects reflects the complexity of working with living organisms: the finite and limited input of individuals, their relatedness (ecological and/or genetic), and the need to group organisms into functional experimental units to estimate population parameters (e.g., cohort replicates). Several decades ago, when the issue of pseudoreplication was first recognized, it was highlighted that mainstream statistical tools were unable to account for the lack of independence. For example, the variability as a result of differences across individuals would be confounded with that of the experimental units where they were observed (e.g., pans for mosquito larvae), whereas both sources of variability now can be separated using modern statistical techniques, such as the linear mixed effects model, that explicitly consider the different scales of variability in a dataset (e.g., mosquitoes and pans). However, the perception of pseudoreplication as a problem without solution remains. This study presents concepts to critically appraise pseudoreplication and the linear mixed effects model as a statistical solution for analyzing data with pseudoreplication, by separating the different sources of variability and thereby generating correct inferences from data gathered in studies with constraints in randomization.

  14. Ceramic Ink-Jet Printing for Digital Decoration: Physical Constraints for Ink Design.

    PubMed

    Gardini, Davide; Blosi, Magda; Zanelli, Chiara; Dondi, Michele

    2015-05-01

    In the last decade, the drop-on-demand (DOD) ink-jet printing has become the leading technology for the decoration of ceramic tiles. The inks employed for such application are colloidal suspensions of oxide particles (0.3 μm) whose stability (against agglomeration and over time) is fundamental to get successfully the tile decoration. Jettability from the DOD print heads is a key requirement along with proper colour after sintering. This means that a careful set up of inks properties (viscosity, density, surface tension) is required. The phenomena involved in the different stages of the ink-jet printing process (drop ejection from the nozzles, impact and spreading on the substrates) are described through dimensionless numbers as Reynolds, Weber, and Bond numbers, or their combinations. In literature physical constraints, obtained with a semi-theoretical approach on the basis of experimental evidences on other systems, allow to define a reference region in the space of the dimensionless numbers (here called "printable fluid region," PFR) where the inks should be suitable for the application. In this paper, 26 inks currently used for ceramic tile decoration were characterized and mapped in the space of dimensionless numbers for several printing conditions. For typical nozzle diameters (20-50 gm) and drop velocities (6-8 m/s), it has been found that they fall in the region identified by 3 < Re < 30, 27 < We < 160, and 0.6 < 1/Oh < 2.5, where Re, We, and Oh, are the Reynolds, Weber and Ohnesorge numbers, respectively. Such experimental region can be taken as reference to tune the colloidal interactions in proper way, though the thresholds delimiting the PFR should be better defined. PMID:26504976

  15. Ceramic Ink-Jet Printing for Digital Decoration: Physical Constraints for Ink Design.

    PubMed

    Gardini, Davide; Blosi, Magda; Zanelli, Chiara; Dondi, Michele

    2015-05-01

    In the last decade, the drop-on-demand (DOD) ink-jet printing has become the leading technology for the decoration of ceramic tiles. The inks employed for such application are colloidal suspensions of oxide particles (0.3 μm) whose stability (against agglomeration and over time) is fundamental to get successfully the tile decoration. Jettability from the DOD print heads is a key requirement along with proper colour after sintering. This means that a careful set up of inks properties (viscosity, density, surface tension) is required. The phenomena involved in the different stages of the ink-jet printing process (drop ejection from the nozzles, impact and spreading on the substrates) are described through dimensionless numbers as Reynolds, Weber, and Bond numbers, or their combinations. In literature physical constraints, obtained with a semi-theoretical approach on the basis of experimental evidences on other systems, allow to define a reference region in the space of the dimensionless numbers (here called "printable fluid region," PFR) where the inks should be suitable for the application. In this paper, 26 inks currently used for ceramic tile decoration were characterized and mapped in the space of dimensionless numbers for several printing conditions. For typical nozzle diameters (20-50 gm) and drop velocities (6-8 m/s), it has been found that they fall in the region identified by 3 < Re < 30, 27 < We < 160, and 0.6 < 1/Oh < 2.5, where Re, We, and Oh, are the Reynolds, Weber and Ohnesorge numbers, respectively. Such experimental region can be taken as reference to tune the colloidal interactions in proper way, though the thresholds delimiting the PFR should be better defined.

  16. Reaction-diffusion constraints in living tissue: effectiveness factors in skeletal muscle design.

    PubMed

    Dasika, S K; Kinsey, S T; Locke, B R

    2011-01-01

    A mathematical model was developed to analyze the effects of intracellular diffusion of O(2) and high-energy phosphate metabolites on aerobic energy metabolism in skeletal muscle. We tested the hypotheses that in a range of muscle fibers from different species (1) aerobic metabolism was not diffusion limited and (2) that fibers had a combination of rate and fiber size that placed them at the brink of substantial diffusion limitation. A simplified chemical reaction rate law for mitochondrial oxidative phosphorylation was developed utilizing a published detailed model of isolated mitochondrial function. This rate law was then used as a boundary condition in a reaction-diffusion model that was further simplified using the volume averaging method and solved to determine the rates of oxidative phosphorylation as functions of the volume fraction of mitochondria, the size of the muscle cell, and the amount of oxygen delivered by the capillaries. The effectiveness factor, which is the ratio of reaction rate in the system with finite rates of diffusion to those in the absence of any diffusion limitations, defined the regions where intracellular diffusion of metabolites and O(2) may limit aerobic metabolism in both very small, highly oxidative fibers as well as in larger fibers with lower aerobic capacity. Comparison of model analysis with experimental data revealed that none of the fibers was strongly limited by diffusion, as expected. However, while some fibers were near substantial diffusion limitation, most were well within the domain of reaction control of aerobic metabolic rate. This may constitute a safety factor in muscle that provides a level of protection from diffusion constraints under conditions such as hypoxia.

  17. Repair Concepts as Design Constraints of a Stiffened Composite PRSEUS Panel

    NASA Technical Reports Server (NTRS)

    Przekop, Adam

    2012-01-01

    A design and analysis of a repair concept applicable to a stiffened thin-skin composite panel based on the Pultruded Rod Stitched Efficient Unitized Structure is presented. The concept is a bolted repair using metal components, so that it can easily be applied in the operational environment. The damage scenario considered is a midbay-to-midbay saw-cut with a severed stiffener, flange and skin. In a previous study several repair configurations were explored and their feasibility confirmed but refinement was needed. The present study revisits the problem under recently revised design requirements and broadens the suite of loading conditions considered. The repair assembly design is based on the critical tension loading condition and subsequently its robustness is verified for a pressure loading case. High fidelity modeling techniques such as mesh-independent definition of compliant fasteners, elastic-plastic material properties for metal parts and geometrically nonlinear solutions are utilized in the finite element analysis. The best repair design is introduced, its analysis results are presented and factors influencing the design are assessed and discussed.

  18. Enforcing compatibility and constraint conditions and information retrieval at the design action

    NASA Technical Reports Server (NTRS)

    Woodruff, George W.

    1990-01-01

    The design of complex entities is a multidisciplinary process involving several interacting groups and disciplines. There is a need to integrate the data in such environments to enhance the collaboration between these groups and to enforce compatibility between dependent data entities. This paper discusses the implementation of a workstation based CAD system that is integrated with a DBMS and an expert system, CLIPS, (both implemented on a mini computer) to provide such collaborative and compatibility enforcement capabilities. The current implementation allows for a three way link between the CAD system, the DBMS and CLIPS. The engineering design process associated with the design and fabrication of sheet metal housing for computers in a large computer manufacturing facility provides the basis for this prototype system.

  19. Designing Energy Supply Chains with the P-graph Framework under Cost Constraints and Sustainability Considerations

    EPA Science Inventory

    A computer-aided methodology for designing sustainable supply chains is presented using the P-graph framework to develop supply chain structures which are analyzed using cost, the cost of producing electricity, and two sustainability metrics: ecological footprint and emergy. They...

  20. Constraint-Driven Software Design: An Escape from the Waterfall Model.

    ERIC Educational Resources Information Center

    de Hoog, Robert; And Others

    1994-01-01

    Presents the principles of a development methodology for software design based on a nonlinear, product-driven approach that integrates quality aspects. Two examples are given to show that the flexibility needed for building high quality systems leads to integrated development environments in which methodology, product, and tools are closely…

  1. Topological design and additive manufacturing of porous metals for bone scaffolds and orthopaedic implants: A review.

    PubMed

    Wang, Xiaojian; Xu, Shanqing; Zhou, Shiwei; Xu, Wei; Leary, Martin; Choong, Peter; Qian, M; Brandt, Milan; Xie, Yi Min

    2016-03-01

    One of the critical issues in orthopaedic regenerative medicine is the design of bone scaffolds and implants that replicate the biomechanical properties of the host bones. Porous metals have found themselves to be suitable candidates for repairing or replacing the damaged bones since their stiffness and porosity can be adjusted on demands. Another advantage of porous metals lies in their open space for the in-growth of bone tissue, hence accelerating the osseointegration process. The fabrication of porous metals has been extensively explored over decades, however only limited controls over the internal architecture can be achieved by the conventional processes. Recent advances in additive manufacturing have provided unprecedented opportunities for producing complex structures to meet the increasing demands for implants with customized mechanical performance. At the same time, topology optimization techniques have been developed to enable the internal architecture of porous metals to be designed to achieve specified mechanical properties at will. Thus implants designed via the topology optimization approach and produced by additive manufacturing are of great interest. This paper reviews the state-of-the-art of topological design and manufacturing processes of various types of porous metals, in particular for titanium alloys, biodegradable metals and shape memory alloys. This review also identifies the limitations of current techniques and addresses the directions for future investigations. PMID:26773669

  2. Topological design and additive manufacturing of porous metals for bone scaffolds and orthopaedic implants: A review.

    PubMed

    Wang, Xiaojian; Xu, Shanqing; Zhou, Shiwei; Xu, Wei; Leary, Martin; Choong, Peter; Qian, M; Brandt, Milan; Xie, Yi Min

    2016-03-01

    One of the critical issues in orthopaedic regenerative medicine is the design of bone scaffolds and implants that replicate the biomechanical properties of the host bones. Porous metals have found themselves to be suitable candidates for repairing or replacing the damaged bones since their stiffness and porosity can be adjusted on demands. Another advantage of porous metals lies in their open space for the in-growth of bone tissue, hence accelerating the osseointegration process. The fabrication of porous metals has been extensively explored over decades, however only limited controls over the internal architecture can be achieved by the conventional processes. Recent advances in additive manufacturing have provided unprecedented opportunities for producing complex structures to meet the increasing demands for implants with customized mechanical performance. At the same time, topology optimization techniques have been developed to enable the internal architecture of porous metals to be designed to achieve specified mechanical properties at will. Thus implants designed via the topology optimization approach and produced by additive manufacturing are of great interest. This paper reviews the state-of-the-art of topological design and manufacturing processes of various types of porous metals, in particular for titanium alloys, biodegradable metals and shape memory alloys. This review also identifies the limitations of current techniques and addresses the directions for future investigations.

  3. Design of additive quantum codes via the code-word-stabilized framework

    SciTech Connect

    Kovalev, Alexey A.; Pryadko, Leonid P.; Dumer, Ilya

    2011-12-15

    We consider design of the quantum stabilizer codes via a two-step, low-complexity approach based on the framework of codeword-stabilized (CWS) codes. In this framework, each quantum CWS code can be specified by a graph and a binary code. For codes that can be obtained from a given graph, we give several upper bounds on the distance of a generic (additive or nonadditive) CWS code, and the lower Gilbert-Varshamov bound for the existence of additive CWS codes. We also consider additive cyclic CWS codes and show that these codes correspond to a previously unexplored class of single-generator cyclic stabilizer codes. We present several families of simple stabilizer codes with relatively good parameters.

  4. Theoretical and experimental investigation of design for multioptical-axis freeform progressive addition lenses

    NASA Astrophysics Data System (ADS)

    Xiang, HuaZhong; Chen, JiaBi; Zhu, TianFen; Wei, YeFei; Fu, DongXiang

    2015-11-01

    A freeform progressive addition lens (PAL) provides a good solution to correct presbyopia and prevent juvenile myopia by distributing pupils' optical powers of distance zone, near zone, and intermediate zone and is more widely adopted in the present optometric study. However, there is still a lack of a single-optical-axis system for the design of a PAL. This paper focuses on the research for an approach for designing a freeform PAL. A multioptical-axis system based on real viewing conditions using the eyes is employed for the representation of the freeform surface. We filled small pupils in the intermediate zone as a progressive corridor and the distance- and near-vision portions were defined as the standard spherical surfaces delimited by quadratic curves. Three freeform PALs with a spherical surface as the front side and a freeform surface as the backside were designed. We demonstrate the fabrication and measurement technologies for the PAL surface using computer numerical control machine tools from Schneider Smart and a Visionix VM-2000 Lens Power Mapper. Surface power and astigmatic values were obtained. Preliminary results showed that the approach for the design and fabrication is helpful to advance the design procedure optimization and mass production of PALs in optometry.

  5. On the design of novel multifunctional materials by using particulate additives

    NASA Astrophysics Data System (ADS)

    Dunnigan, Ross Daniel

    This thesis has been organized into five chapters. The main focus of this thesis is to design novel multifunctional materials by using particulate additives. Chapter 1 is devoted to reviewing recent studies in additive manufacturing (AM) and other background information. In Chapter 2, the synthesis and characterization of novel Ti3SiC2-reinforced Zn-matrix composites is reported. During this study, all the Zn composites were hot pressed at 500°C for 5 min at a uniaxial pressure of ~150 MPa. Microstructure analysis by SEM (Scanning Electron Microscopy) and phase analysis by XRD (X-ray Diffraction) confirmed that there was minimal interfacial reaction between Ti3SiC 2 particles and the Zn matrix. The addition of Ti3SiC 2 improved the tribological performance of these composites against alumina substrates but did not have any beneficial effect on the mechanical performance. The addition of Ti3SiC2 particulates to metal and polymer matrices show interesting properties. Chapter 3 will focus on additive manufacturing of Ti3SiC2 particulates in a polymer matrix. Waste materials are a big problem in the world. Chapters 4 and 5 focus on recycling materials. The mechanical and tribological properties of the Resin-Nylon and ResinPolyester composites are reported, respectively.

  6. Reading patterns in online documentation: How transcript analysis reflects text design, software constraints, and user preferences

    SciTech Connect

    Girill, T.R.; Luk, C.H.; Norton, S.

    1987-02-01

    Text design and text-delivery software together influence the effectiveness of online computer documentation. To explore this relationship, we analyzed transcripts for a typical month of sessions in which users of a supercomputer network consulted online documentation by means of very flexible software. We found that most readers displayed relatively small passages from single documents, often checking a subject index to select those passages. This strong reference-reading pattern confirms and clarifies results from other, more limited studies of online text use. The reference pattern appears even stronger when users accessed task-oriented documents that included many examples.

  7. Designing valid and optimised standard addition calibrations: Application to the determination of anions in seawater.

    PubMed

    Rodrigues, Joana; da Silva, Ricardo J N Bettencourt; Camões, M Filomena G F C; Oliveira, Cristina M

    2015-09-01

    A strategy for designing valid standard addition calibrations and for optimising their uncertainty is presented. The design of calibrations involves the development of models of the sensitivity and precision of the instrumental signal, in a wide range of analyte concentration (or any other studied quantity), and the definition of sample dilution and standard addition procedures that allow fulfilling the assumptions of the linear unweighted regression model in, typically, a smaller range of standard addition calibrations. Calibrators are prepared by diluting the sample and adding analyte with negligible uncertainty to fit in a concentration range where signals are homoscedastic. The minimisation of the uncertainty is supported on detailed measurement uncertainty models function of the calibrators preparation procedure and of analytical instrumentation performance. The number of collected signals replicates is defined by balancing their impact on the estimated expanded uncertainty, the resources needed and the target (maximum) uncertainty for the intended use of measurements. The calibration design strategy was successfully applied to the determination of the mass concentration (mg L(-1)) of Cl(-), Br(-), NO3(-) and SO4(-2) in seawater by ion chromatography. A target expanded uncertainty of 20% was defined for the determination of Cl(-), NO3(-) and SO4(-2), or 40% for the determination of the smaller mass concentration of Br(-). The developed measurement model produced reliable predictions of the measurement uncertainty from approximate concentration of the analyte in the sample, before its accurate quantification, thus proving optimisation is effective. Predictions are more prone to the variability of the measurement uncertainty estimation if based on low number of calibrators signals. The reported relative expanded uncertainty ranged from 7.1% to 49%.

  8. Deriving topological constraints from functional data for the design of reagentless fluorescent immunosensors.

    PubMed

    Renard, Martial; Belkadi, Laurent; Bedouelle, Hugues

    2003-02-01

    The possibility of obtaining, from any antibody, a fluorescent conjugate which responds to the binding of the antigen by a variation of fluorescence, would be of great interest in the micro- and nano-analytical sciences. This possibility was explored with antibody mAb4E11, which is directed against the dengue virus and for which no structural data is available. Three rules of design were developed to identify residues of the antibody to which a fluorophore could be chemically coupled, after changing them to cysteine by mutagenesis. (i) The target residue belonged to the hypervariable loops of the antibody. (ii) It was adjacent, along the amino acid sequence of the antibody, to a residue which was functionally important for the interaction with the antigen. (iii) It was not important in itself for the interaction with the antigen. Eight conjugates between a single chain variable fragment of mAb4E11 and an environment-sensitive fluorophore were constructed. Three of them showed an increase in their fluorescence intensity by 1.5-2.8-fold on antigen binding, without loss of affinity. This increase allowed the titration of the antigen in serum above a threshold concentration of 10nM. Experiments of quenching with potassium iodide suggested that the fluorescence variation was due to a shielding of the fluorescent group from the solvent by the binding of the antigen, and that therefore its mechanism is general.

  9. Conflict-cost based random sampling design for parallel MRI with low rank constraints

    NASA Astrophysics Data System (ADS)

    Kim, Wan; Zhou, Yihang; Lyu, Jingyuan; Ying, Leslie

    2015-05-01

    In compressed sensing MRI, it is very important to design sampling pattern for random sampling. For example, SAKE (simultaneous auto-calibrating and k-space estimation) is a parallel MRI reconstruction method using random undersampling. It formulates image reconstruction as a structured low-rank matrix completion problem. Variable density (VD) Poisson discs are typically adopted for 2D random sampling. The basic concept of Poisson disc generation is to guarantee samples are neither too close to nor too far away from each other. However, it is difficult to meet such a condition especially in the high density region. Therefore the sampling becomes inefficient. In this paper, we present an improved random sampling pattern for SAKE reconstruction. The pattern is generated based on a conflict cost with a probability model. The conflict cost measures how many dense samples already assigned are around a target location, while the probability model adopts the generalized Gaussian distribution which includes uniform and Gaussian-like distributions as special cases. Our method preferentially assigns a sample to a k-space location with the least conflict cost on the circle of the highest probability. To evaluate the effectiveness of the proposed random pattern, we compare the performance of SAKEs using both VD Poisson discs and the proposed pattern. Experimental results for brain data show that the proposed pattern yields lower normalized mean square error (NMSE) than VD Poisson discs.

  10. Optimal receiver design for diffusive molecular communication with flow and additive noise.

    PubMed

    Noel, Adam; Cheung, Karen C; Schober, Robert

    2014-09-01

    In this paper, we perform receiver design for a diffusive molecular communication environment. Our model includes flow in any direction, sources of information molecules in addition to the transmitter, and enzymes in the propagation environment to mitigate intersymbol interference. We characterize the mutual information between receiver observations to show how often independent observations can be made. We derive the maximum likelihood sequence detector to provide a lower bound on the bit error probability. We propose the family of weighted sum detectors for more practical implementation and derive their expected bit error probability. Under certain conditions, the performance of the optimal weighted sum detector is shown to be equivalent to a matched filter. Receiver simulation results show the tradeoff in detector complexity versus achievable bit error probability, and that a slow flow in any direction can improve the performance of a weighted sum detector.

  11. Biomechanical investigation into the structural design of porous additive manufactured cages using numerical and experimental approaches.

    PubMed

    Tsai, Pei-I; Hsu, Ching-Chi; Chen, San-Yuan; Wu, Tsung-Han; Huang, Chih-Chieh

    2016-09-01

    Traditional solid cages have been widely used in posterior lumbar interbody fusion (PLIF) surgery. However, solid cages significantly affect the loading mechanism of the human spine due to their extremely high structural stiffness. Previous studies proposed and investigated porous additive manufactured (AM) cages; however, their biomechanical performances were analyzed using oversimplified bone-implant numerical models. Thus, the aim of this study was to investigate the outer shape and inner porous structure of the AM cages. The outer shape of the AM cages was discovered using a simulation-based genetic algorithm; their inner porous structure was subsequently analyzed parametrically using T10-S1 multilevel spine models. Finally, six types of the AM cages, which were manufactured using selective laser melting, were tested to validate the numerical outcomes. The subsidence resistance of the optimum design was superior to the conventional cage designs. A porous AM cage with a pillar diameter of 0.4mm, a pillar angle of 40°, and a porosity of between 69% and 80% revealed better biomechanical performances. Both the numerical and experimental outcomes can help surgeons to understand the biomechanics of PLIF surgery combined with the use of AM cages. PMID:27392226

  12. Design of a mechanical system in gait rehabilitation with progressive addition of weight

    NASA Astrophysics Data System (ADS)

    Braidot, Ariel A. A.; Aleman, Guillermo L.

    2011-12-01

    In this paper we designed and developed a mechanical device for gait rehabilitation based on the application of "partial body weight reduction therapy". An evaluation of the characteristics of devices based on this therapy currently available on the market was carried out obtaining information of the different mechanisms used in it. The device was designed to adapt to different height and weight of patients and to be used with additional equipment in gait rehabilitation, for example, treadmills, elliptical trainers and vertical scalers. It was envisaged to be used by patients with asymmetry in the lower extremities capabilities. We developed a stable structure in steel ASTM A36 which does not depend on the building conditions of the installation site. RamAdvanse software was used to calculate structural stability. A winch with automatic brake mechanism was used to raise/lower the patient, who was tied to a comfortable harness which provided safety to the patient and therapist. It was possible to quantify precisely, using counterweights, the weight borne by the patient during therapy. We obtained a small-sized and ergonomic low-cost prototype, with similar features to those currently considered cutting-edge devices.

  13. Towards the design of new and improved drilling fluid additives using molecular dynamics simulations.

    PubMed

    Anderson, Richard L; Greenwel, H Christopher; Suter, James L; Jarvis, Rebecca M; Coveney, Peter V

    2010-03-01

    During exploration for oil and gas, a technical drilling fluid is used to lubricate the drill bit, maintain hydrostatic pressure, transmit sensor readings, remove rock cuttings and inhibit swelling of unstable clay based reactive shale formations. Increasing environmental awareness and resulting legislation has led to the search for new, improved biodegradable drilling fluid components. In the case of additives for clay swelling inhibition, an understanding of how existing effective additives interact with clays must be gained to allow the design of improved molecules. Owing to the disordered nature and nanoscopic dimension of the interlayer pores of clay minerals, computer simulations have become an increasingly useful tool for studying clay-swelling inhibitor interactions. In this work we briefly review the history of the development of technical drilling fluids, the environmental impact of drilling fluids and the use of computer simulations to study the interactions between clay minerals and swelling inhibitors. We report on results from some recent large-scale molecular dynamics simulation studies on low molecular weight water-soluble macromolecular inhibitor molecules. The structure and interactions of poly(propylene oxide)-diamine, poly(ethylene glycol) and poly(ethylene oxide)-diacrylate inhibitor molecules with montmorillonite clay are studied.

  14. Cloud-Based Automated Design and Additive Manufacturing: A Usage Data-Enabled Paradigm Shift.

    PubMed

    Lehmhus, Dirk; Wuest, Thorsten; Wellsandt, Stefan; Bosse, Stefan; Kaihara, Toshiya; Thoben, Klaus-Dieter; Busse, Matthias

    2015-12-19

    Integration of sensors into various kinds of products and machines provides access to in-depth usage information as basis for product optimization. Presently, this large potential for more user-friendly and efficient products is not being realized because (a) sensor integration and thus usage information is not available on a large scale and (b) product optimization requires considerable efforts in terms of manpower and adaptation of production equipment. However, with the advent of cloud-based services and highly flexible additive manufacturing techniques, these obstacles are currently crumbling away at rapid pace. The present study explores the state of the art in gathering and evaluating product usage and life cycle data, additive manufacturing and sensor integration, automated design and cloud-based services in manufacturing. By joining and extrapolating development trends in these areas, it delimits the foundations of a manufacturing concept that will allow continuous and economically viable product optimization on a general, user group or individual user level. This projection is checked against three different application scenarios, each of which stresses different aspects of the underlying holistic concept. The following discussion identifies critical issues and research needs by adopting the relevant stakeholder perspectives.

  15. Cloud-Based Automated Design and Additive Manufacturing: A Usage Data-Enabled Paradigm Shift

    PubMed Central

    Lehmhus, Dirk; Wuest, Thorsten; Wellsandt, Stefan; Bosse, Stefan; Kaihara, Toshiya; Thoben, Klaus-Dieter; Busse, Matthias

    2015-01-01

    Integration of sensors into various kinds of products and machines provides access to in-depth usage information as basis for product optimization. Presently, this large potential for more user-friendly and efficient products is not being realized because (a) sensor integration and thus usage information is not available on a large scale and (b) product optimization requires considerable efforts in terms of manpower and adaptation of production equipment. However, with the advent of cloud-based services and highly flexible additive manufacturing techniques, these obstacles are currently crumbling away at rapid pace. The present study explores the state of the art in gathering and evaluating product usage and life cycle data, additive manufacturing and sensor integration, automated design and cloud-based services in manufacturing. By joining and extrapolating development trends in these areas, it delimits the foundations of a manufacturing concept that will allow continuous and economically viable product optimization on a general, user group or individual user level. This projection is checked against three different application scenarios, each of which stresses different aspects of the underlying holistic concept. The following discussion identifies critical issues and research needs by adopting the relevant stakeholder perspectives. PMID:26703606

  16. Cloud-Based Automated Design and Additive Manufacturing: A Usage Data-Enabled Paradigm Shift.

    PubMed

    Lehmhus, Dirk; Wuest, Thorsten; Wellsandt, Stefan; Bosse, Stefan; Kaihara, Toshiya; Thoben, Klaus-Dieter; Busse, Matthias

    2015-01-01

    Integration of sensors into various kinds of products and machines provides access to in-depth usage information as basis for product optimization. Presently, this large potential for more user-friendly and efficient products is not being realized because (a) sensor integration and thus usage information is not available on a large scale and (b) product optimization requires considerable efforts in terms of manpower and adaptation of production equipment. However, with the advent of cloud-based services and highly flexible additive manufacturing techniques, these obstacles are currently crumbling away at rapid pace. The present study explores the state of the art in gathering and evaluating product usage and life cycle data, additive manufacturing and sensor integration, automated design and cloud-based services in manufacturing. By joining and extrapolating development trends in these areas, it delimits the foundations of a manufacturing concept that will allow continuous and economically viable product optimization on a general, user group or individual user level. This projection is checked against three different application scenarios, each of which stresses different aspects of the underlying holistic concept. The following discussion identifies critical issues and research needs by adopting the relevant stakeholder perspectives. PMID:26703606

  17. 77 FR 38835 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-29

    ... HUMAN SERVICES Final Effect of Designation of a Class of Employees for Addition to the Special Exposure... notice concerning the final effect of the HHS decision to designate a class of employees from the Brookhaven National Laboratory in Upton, New York, as an addition to the Special Exposure Cohort (SEC)...

  18. 77 FR 38835 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-29

    ... HUMAN SERVICES Final Effect of Designation of a Class of Employees for Addition to the Special Exposure... notice concerning the final effect of the HHS decision to designate a class of employees from the Electro Metallurgical site in Niagara Falls, New York, as an addition to the Special Exposure Cohort (SEC) under...

  19. 77 FR 38835 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-29

    ... HUMAN SERVICES Final Effect of Designation of a Class of Employees for Addition to the Special Exposure... notice concerning the final effect of the HHS decision to designate a class of employees from the Sandia National Laboratories in Albuquerque, New Mexico, as an addition to the Special Exposure Cohort (SEC)...

  20. Extracellular matrix protein in calcified endoskeleton: a potential additive for crystal growth and design

    NASA Astrophysics Data System (ADS)

    Azizur Rahman, M.; Fujimura, Hiroyuki; Shinjo, Ryuichi; Oomori, Tamotsu

    2011-06-01

    In this study, we demonstrate a key function of extracellular matrix proteins (ECMPs) on seed crystals, which are isolated from calcified endoskeletons of soft coral and contain only CaCO 3 without any living cells. This is the first report that an ECMP protein extracted from a marine organism could potentially influence in modifying the surface of a substrate for designing materials via crystallization. We previously studied with the ECMPs from a different type of soft coral ( Sinularia polydactyla) without introducing any seed crystals in the process , which showed different results. Thus, crystallization on the seed in the presence of ECMPs of present species is an important first step toward linking function to individual proteins from soft coral. For understanding this interesting phenomenon, in vitro crystallization was initiated in a supersaturated solution on seed particles of calcite (1 0 4) with and without ECMPs. No change in the crystal growth shape occurred without ECMPs present during the crystallization process. However, with ECMPs, the morphology and phase of the crystals in the crystallization process changed dramatically. Upon completion of crystallization with ECMPs, an attractive crystal morphology was found. Scanning electron microscopy (SEM) was utilized to observe the crystal morphologies on the seeds surface. The mineral phases of crystals nucleated by ECMPs on the seeds surface were examined by Raman spectroscopy. Although 50 mM Mg 2+ is influential in making aragonite in the crystallization process, the ECMPs significantly made calcite crystals even when 50 mM Mg 2+ was present in the process. Crystallization with the ECMP additive seems to be a technically attractive strategy to generate assembled micro crystals that could be used in crystals growth and design in the Pharmaceutical and biotechnology industries.

  1. Additive Manufacturing, Design, Testing, and Fabrication: A Full Engineering Experience at JSC

    NASA Technical Reports Server (NTRS)

    Zusack, Steven

    2016-01-01

    I worked on several projects this term. While most projects involved additive manufacturing, I was also involved with two design projects, two testing projects, and a fabrication project. The primary mentor for these was Richard Hagen. Secondary mentors were Hai Nguyen, Khadijah Shariff, and fabrication training from James Brown. Overall, my experience at JSC has been successful and what I have learned will continue to help me in my engineering education and profession long after I leave. My 3D printing projects ranged from less than a 1 cubic centimeter to about 1 cubic foot and involved several printers using different printing technologies. It was exciting to become familiar with printing technologies such as industrial grade FDM (Fused Deposition Modeling), the relatively new SLA (Stereolithography), and PolyJet. My primary duty with the FDM printers was to model parts that came in from various sources to print effectively and efficiently. Using methods my mentor taught me and the Stratasys Insight software, I was able to minimize imperfections, hasten build time, improve strength for specific forces (tensile, shear, etc...), and reduce likelihood of a print-failure. Also using FDM, I learned how to repair a part after it was printed. This is done by using a special kind of glue that chemically melts the two faces of plastic parts together to form a fused interface. My first goal with SLA technology was to bring the printer back to operational readiness. In becoming familiar with the Pegasus SLA printer, I researched the leveling, laser settings, and different vats to hold liquid material. With this research, I was successfully able to bring the Pegasus back online and have successfully printed multiple sample parts as well as functional parts. My experience with PolyJet technology has been focused on an understanding of the abilities/limits, costs, and the maintenance for daily use. Still upcoming will be experience with using a composite printer that uses FDM

  2. Automated microbial metabolism laboratory. [design of advanced labeled release experiment based on single addition of soil and multiple sequential additions of media into test chambers

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The design and rationale of an advanced labeled release experiment based on single addition of soil and multiple sequential additions of media into each of four test chambers are outlined. The feasibility for multiple addition tests was established and various details of the methodology were studied. The four chamber battery of tests include: (1) determination of the effect of various atmospheric gases and selection of that gas which produces an optimum response; (2) determination of the effect of incubation temperature and selection of the optimum temperature for performing Martian biochemical tests; (3) sterile soil is dosed with a battery of C-14 labeled substrates and subjected to experimental temperature range; and (4) determination of the possible inhibitory effects of water on Martian organisms is performed initially by dosing with 0.01 ml and 0.5 ml of medium, respectively. A series of specifically labeled substrates are then added to obtain patterns in metabolic 14CO2 (C-14)O2 evolution.

  3. A “Reverse-Schur” Approach to Optimization With Linear PDE Constraints: Application to Biomolecule Analysis and Design

    PubMed Central

    Bardhan, Jaydeep P.; Altman, Michael D.

    2009-01-01

    We present a partial-differential-equation (PDE)-constrained approach for optimizing a molecule’s electrostatic interactions with a target molecule. The approach, which we call reverse-Schur co-optimization, can be more than two orders of magnitude faster than the traditional approach to electrostatic optimization. The efficiency of the co-optimization approach may enhance the value of electrostatic optimization for ligand-design efforts–in such projects, it is often desirable to screen many candidate ligands for their viability, and the optimization of electrostatic interactions can improve ligand binding affinity and specificity. The theoretical basis for electrostatic optimization derives from linear-response theory, most commonly continuum models, and simple assumptions about molecular binding processes. Although the theory has been used successfully to study a wide variety of molecular binding events, its implications have not yet been fully explored, in part due to the computational expense associated with the optimization. The co-optimization algorithm achieves improved performance by solving the optimization and electrostatic simulation problems simultaneously, and is applicable to both unconstrained and constrained optimization problems. Reverse-Schur co-optimization resembles other well-known techniques for solving optimization problems with PDE constraints. Model problems as well as realistic examples validate the reverse-Schur method, and demonstrate that our technique and alternative PDE-constrained methods scale very favorably compared to the standard approach. Regularization, which ordinarily requires an explicit representation of the objective function, can be included using an approximate Hessian calculated using the new BIBEE/P (boundary-integral-based electrostatics estimation by preconditioning) method. PMID:23055839

  4. 76 FR 33762 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-09

    ... decision to designate a class of employees from the Wah Chang facility, Albany, Oregon, as an addition to... who worked in any building at the Wah Chang facility in Albany, Oregon, for the operational...

  5. 78 FR 64500 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-29

    ... addition to the Special Exposure Cohort (SEC) under the Energy Employees Occupational Illness Compensation... employees as an addition to the SEC: All employees of the Feed Materials Production Center (FMPC) in Fernald... notice in the Federal Register reporting the addition of this class to the SEC or the result of...

  6. 75 FR 44968 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-30

    ..., New Mexico, as an addition to the Special Exposure Cohort (SEC) under the Energy Employees... following class of employees as an addition to the SEC: All employees of the Department of Energy, its... Register reporting the addition of this class to the SEC or the result of any provision by...

  7. 78 FR 77685 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-24

    ... an addition to the Special Exposure Cohort (SEC) under the Energy Employees Occupational Illness... employees as an addition to the SEC: ] All employees of the Department of Energy, its predecessor agencies... notice in the Federal Register reporting the addition of this class to the SEC or the result of...

  8. 78 FR 64501 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-29

    ... addition to the Special Exposure Cohort (SEC) under the Energy Employees Occupational Illness Compensation... employees as an addition to the SEC: All employees of the Department of Energy, its predecessor agencies... Register reporting the addition of this class to the SEC or the result of any provision by...

  9. 75 FR 44968 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-30

    ..., Missouri, as an addition to the Special Exposure Cohort (SEC) under the Energy Employees Occupational... class of employees as an addition to the SEC: All employees of the Department of Energy, its predecessor... publish a notice in the Federal Register reporting the addition of this class to the SEC or the result...

  10. 75 FR 44966 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-30

    ... County, California, as an addition to the Special Exposure Cohort (SEC) under the Energy Employees... following class of employees as an addition to the SEC: All employees of the Department of Energy, its... Federal Register reporting the addition of this class to the SEC or the result of any provision...

  11. 75 FR 44966 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-30

    ... York, as an addition to the Special Exposure Cohort (SEC) under the Energy Employees Occupational... class of employees as an addition to the SEC: All Atomic Weapons Employer employees who worked at the... publish a notice in the Federal Register reporting the addition of this class to the SEC or the result...

  12. 78 FR 21954 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-12

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Final Effect of Designation of a Class of Employees for Addition to the Special Exposure... notice concerning the final effect of the HHS decision to designate a class of employees from...

  13. 78 FR 70949 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-27

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Final Effect of Designation of a Class of Employees for Addition to the Special Exposure... notice concerning the final effect of the HHS decision to designate a class of employees from the...

  14. 77 FR 60437 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-03

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Final Effect of Designation of a Class of Employees for Addition to the Special Exposure... notice concerning the final effect of the HHS decision to designate a class of employees from the...

  15. 75 FR 3470 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-21

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Final Effect of Designation of a Class of Employees for Addition to the Special Exposure... notice concerning the final effect of the HHS decision to designate a class of employees at...

  16. 77 FR 38834 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-29

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Final Effect of Designation of a Class of Employees for Addition to the Special Exposure... notice concerning the final effect of the HHS decision to designate a class of employees from...

  17. 78 FR 3897 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-17

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Final Effect of Designation of a Class of Employees for Addition to the Special Exposure... notice concerning the final effect of the HHS decision to designate a class of employees from the...

  18. 75 FR 37812 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-30

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Final Effect of Designation of a Class of Employees for Addition to the Special Exposure... notice concerning the final effect of the HHS decision to designate a class of employees at the...

  19. 78 FR 21954 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-12

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Final Effect of Designation of a Class of Employees for Addition to the Special Exposure... notice concerning the final effect of the HHS decision to designate a class of employees from the...

  20. 77 FR 46438 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-03

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Final Effect of Designation of a Class of Employees for Addition to the Special Exposure... notice concerning the final effect of the HHS decision to designate a class of employees from the...

  1. 77 FR 15759 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-16

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Final Effect of Designation of a Class of Employees for Addition to the Special Exposure... notice concerning the final effect of the HHS decision to designate a class of employees from...

  2. 75 FR 3469 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-21

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Final Effect of Designation of a Class of Employees for Addition to the Special Exposure... notice concerning the final effect of the HHS decision to designate a class of employees at the...

  3. 78 FR 3898 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-17

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Final Effect of Designation of a Class of Employees for Addition to the Special Exposure... notice concerning the final effect of the HHS decision to designate a class of employees from Oak...

  4. 77 FR 60438 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-03

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Final Effect of Designation of a Class of Employees for Addition to the Special Exposure... notice concerning the final effect of the HHS decision to designate a class of employees from...

  5. 78 FR 3898 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-17

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF HEALTH AND HUMAN SERVICES Final Effect of Designation of a Class of Employees for Addition to the Special Exposure... notice concerning the final effect of the HHS decision to designate a class of employees from the...

  6. 78 FR 21955 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-12

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Final Effect of Designation of a Class of Employees for Addition to the Special Exposure... notice concerning the final effect of the HHS decision to designate a class of employees from the...

  7. 77 FR 69845 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-21

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Final Effect of Designation of a Class of Employees for Addition to the Special Exposure... notice concerning the final effect of the HHS decision to designate a class of employees from the...

  8. 75 FR 51817 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-23

    ... HUMAN SERVICES National Institute for Occupational Safety and Health Final Effect of Designation of a...: HHS gives notice concerning the final effect of the HHS decision to designate a class of employees from BWX Technologies, Inc., in Lynchburg, Virginia, as an addition to the Special Exposure Cohort...

  9. 77 FR 58382 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-20

    ... designate a class of employees from Winchester Engineering and Analytical Center in Winchester... Analytical Center in Winchester, Massachusetts, from January 1, 1952, through December 31, 1961, for a...

  10. Modeling Longitudinal Data with Generalized Additive Models: Applications to Single-Case Designs

    ERIC Educational Resources Information Center

    Sullivan, Kristynn J.; Shadish, William R.

    2013-01-01

    Single case designs (SCDs) are short time series that assess intervention effects by measuring units repeatedly over time both in the presence and absence of treatment. For a variety of reasons, interest in the statistical analysis and meta-analysis of these designs has been growing in recent years. This paper proposes modeling SCD data with…

  11. 77 FR 76490 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-28

    ... designate a class of employees from the Oak Ridge National Laboratory (X-10) in Oak Ridge, Tennessee, as an... Program Act of 2000. On December 7, 2012, the Secretary of HHS designated the following class of employees... their contractors and subcontractors who worked in any area at the Oak Ridge National Laboratory...

  12. 75 FR 44966 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-30

    ..., as an addition to the Special Exposure Cohort (SEC) under the Energy Employees Occupational Illness... employees as an addition to the SEC: All Atomic Weapons Employer employees who worked at BWX Technologies... class to the SEC or the result of any provision by Congress regarding the decision by HHS to add...

  13. 77 FR 58382 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-20

    ... Special Exposure Cohort (SEC) under the Energy Employees Occupational Illness Compensation Program Act of... addition to the SEC: All employees of the Department of Energy, its predecessor agencies, and their... addition of this class to the SEC or the result of any provision by Congress regarding the decision by...

  14. 77 FR 64996 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-24

    ... the Special Exposure Cohort (SEC) under the Energy Employees Occupational Illness Compensation Program... an addition to the SEC: All Atomic Weapons Employees who worked for the Ventron Corporation at its... publish a notice in the Federal Register reporting the addition of this class to the SEC or the result...

  15. 78 FR 18351 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-26

    ... designate a class of employees from the Battelle Laboratories King Avenue facility in Columbus, Ohio, as an... Battelle Laboratories in Columbus, Ohio, during the period from April 16, 1943, through June 30, 1956,...

  16. 77 FR 58381 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-20

    ... designate a class of employees from Clarksville Modification Center, Ft. Campbell, in Clarksville, Tennessee... Campbell, in Clarksville, Tennessee, from August 1, 1949, through December 31, 1967, for a number of...

  17. 76 FR 28435 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-17

    ...). ACTION: Notice. SUMMARY: HHS gives notice of a decision to designate a class of employees from the Vitro... Employer employees who worked at Vitro Manufacturing in Canonsburg, Pennsylvania, from January 1,...

  18. 76 FR 68459 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-04

    ...). ACTION: Notice. SUMMARY: HHS gives notice of a decision to designate a class of employees from Vitro... Employees who worked at Vitro Manufacturing in Canonsburg, Pennsylvania, from January 1, 1960...

  19. 10 CFR 60.133 - Additional design criteria for the underground facility.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... deleterious rock movement or fracturing of overlying or surrounding rock. (f) Rock excavation. The design of... creating a preferential pathway for groundwater to contact the waste packages or radionuclide migration to... rock, and surrounding strata, groundwater system....

  20. 10 CFR 60.133 - Additional design criteria for the underground facility.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... deleterious rock movement or fracturing of overlying or surrounding rock. (f) Rock excavation. The design of... creating a preferential pathway for groundwater to contact the waste packages or radionuclide migration to... rock, and surrounding strata, groundwater system....

  1. 10 CFR 60.133 - Additional design criteria for the underground facility.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... deleterious rock movement or fracturing of overlying or surrounding rock. (f) Rock excavation. The design of... creating a preferential pathway for groundwater to contact the waste packages or radionuclide migration to... rock, and surrounding strata, groundwater system....

  2. 10 CFR 60.133 - Additional design criteria for the underground facility.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... deleterious rock movement or fracturing of overlying or surrounding rock. (f) Rock excavation. The design of... creating a preferential pathway for groundwater to contact the waste packages or radionuclide migration to... rock, and surrounding strata, groundwater system....

  3. 10 CFR 60.133 - Additional design criteria for the underground facility.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... deleterious rock movement or fracturing of overlying or surrounding rock. (f) Rock excavation. The design of... creating a preferential pathway for groundwater to contact the waste packages or radionuclide migration to... rock, and surrounding strata, groundwater system....

  4. 75 FR 44967 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-30

    ... of a decision to designate a class of employees from the Mound Plant in Miamisburg, Ohio, as an... Mound Plant in Miamisburg, Ohio from March 1, 1959 through March 5, 1980, for a number of work...

  5. 76 FR 28436 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-17

    ... Chang facility in Albany, Oregon, as an addition to the Special Exposure Cohort (SEC) under the Energy... who worked in any building at the Wah Chang facility in Albany, Oregon, for the operational...

  6. 76 FR 26299 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-06

    ... Linde Ceramics Plant in Tonawanda, New York, as an addition to the Special Exposure Cohort (SEC) under... Employees who worked at the Linde Ceramics Plant in Tonawanda, New York, from January 1, 1954...

  7. 76 FR 68459 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-04

    ... and Company in Curtis Bay, Maryland, as an addition to the Special Exposure Cohort (SEC) under the... Employees who worked at any building or area at the facility owned by W.R. Grace and Company in Curtis...

  8. 76 FR 57044 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-15

    ... General Electric Co. in Evendale, Ohio, as an addition to the Special Exposure Cohort (SEC) under the... General Electric Co. in Evendale, Ohio, from January 1, 1961 through June 30, 1970, for a number of...

  9. CHARMM additive and polarizable force fields for biophysics and computer-aided drug design

    PubMed Central

    Vanommeslaeghe, K.

    2014-01-01

    Background Molecular Mechanics (MM) is the method of choice for computational studies of biomolecular systems owing to its modest computational cost, which makes it possible to routinely perform molecular dynamics (MD) simulations on chemical systems of biophysical and biomedical relevance. Scope of Review As one of the main factors limiting the accuracy of MD results is the empirical force field used, the present paper offers a review of recent developments in the CHARMM additive force field, one of the most popular bimolecular force fields. Additionally, we present a detailed discussion of the CHARMM Drude polarizable force field, anticipating a growth in the importance and utilization of polarizable force fields in the near future. Throughout the discussion emphasis is placed on the force fields’ parametrization philosophy and methodology. Major Conclusions Recent improvements in the CHARMM additive force field are mostly related to newly found weaknesses in the previous generation of additive force fields. Beyond the additive approximation is the newly available CHARMM Drude polarizable force field, which allows for MD simulations of up to 1 microsecond on proteins, DNA, lipids and carbohydrates. General Significance Addressing the limitations ensures the reliability of the new CHARMM36 additive force field for the types of calculations that are presently coming into routine computational reach while the availability of the Drude polarizable force fields offers a model that is an inherently more accurate model of the underlying physical forces driving macromolecular structures and dynamics. PMID:25149274

  10. Design of high-performing hybrid meta-heuristics for unrelated parallel machine scheduling with machine eligibility and precedence constraints

    NASA Astrophysics Data System (ADS)

    Afzalirad, Mojtaba; Rezaeian, Javad

    2016-04-01

    This study involves an unrelated parallel machine scheduling problem in which sequence-dependent set-up times, different release dates, machine eligibility and precedence constraints are considered to minimize total late works. A new mixed-integer programming model is presented and two efficient hybrid meta-heuristics, genetic algorithm and ant colony optimization, combined with the acceptance strategy of the simulated annealing algorithm (Metropolis acceptance rule), are proposed to solve this problem. Manifestly, the precedence constraints greatly increase the complexity of the scheduling problem to generate feasible solutions, especially in a parallel machine environment. In this research, a new corrective algorithm is proposed to obtain the feasibility in all stages of the algorithms. The performance of the proposed algorithms is evaluated in numerical examples. The results indicate that the suggested hybrid ant colony optimization statistically outperformed the proposed hybrid genetic algorithm in solving large-size test problems.

  11. Rational design of solution additives for the prevention of protein aggregation.

    PubMed

    Baynes, Brian M; Trout, Bernhardt L

    2004-09-01

    We have developed a statistical-mechanical model of the effect of solution additives on protein association reactions. This model incorporates solvent radial distribution functions obtained from all-atom molecular dynamics simulations of particular proteins into simple models of protein interactions. In this way, the effects of additives can be computed along the entire association/dissociation reaction coordinate. We used the model to test our hypothesis that a class of large solution additives, which we term "neutral crowders," can slow protein association and dissociation by being preferentially excluded from protein-protein encounter complexes, in a manner analogous to osmotic stress. The magnitude of this proposed "gap effect" was probed for two simple model systems: the association of two spheres and the association of two planes. Our results suggest that for a protein of 20 A radius, an 8 A additive can increase the free energy barrier for association and dissociation by as much as 3-6 kcal/mol. Because the proposed gap effect is present only for reactions involving multiple molecules, it can be exploited to develop novel additives that affect protein association reactions although having little or no effect on unimolecular reactions such as protein folding. This idea has many potential applications in areas such as the stabilization of proteins against aggregation during folding and in pharmaceutical formulations.

  12. Large Advanced Space Systems (LASS) computer-aided design program additions

    NASA Technical Reports Server (NTRS)

    Farrell, C. E.

    1982-01-01

    The LSS preliminary and conceptual design requires extensive iteractive analysis because of the effects of structural, thermal, and control intercoupling. A computer aided design program that will permit integrating and interfacing of required large space system (LSS) analyses is discussed. The primary objective of this program is the implementation of modeling techniques and analysis algorithms that permit interactive design and tradeoff studies of LSS concepts. Eight software modules were added to the program. The existing rigid body controls module was modified to include solar pressure effects. The new model generator modules and appendage synthesizer module are integrated (interfaced) to permit interactive definition and generation of LSS concepts. The mass properties module permits interactive specification of discrete masses and their locations. The other modules permit interactive analysis of orbital transfer requirements, antenna primary beam n, and attitude control requirements.

  13. 76 FR 73758 - Additional Designation of Four Entities Pursuant to Executive Order 13382

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-29

    ...: Designation of Nuclear Reactors Fuel Company (SUREH), Noor Afzar Gostar Company (NAGCO), Fulmen Group, and... determined that four Iranian entities, Nuclear Reactors Fuel Company (SUREH), Noor Afzar Gostar Company... NUCLEAR REACTORS FUEL COMPANY (a.k.a.: SUREH. Location: 61 Shahid Abtahi St., Karegar e Shomali,...

  14. 76 FR 52384 - Designation of Additional Entities Pursuant to Executive Order 13405

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-22

    ... Democratic Processes or Institutions in Belarus.'' DATES: The designation by the Director of OFAC of the four... repression, electoral fraud, and public corruption in Belarus. The Order imposes economic sanctions on persons responsible for actions or policies that undermine democratic processes or institutions in...

  15. Laser and electron-beam powder-bed additive manufacturing of metallic implants: A review on processes, materials and designs.

    PubMed

    Sing, Swee Leong; An, Jia; Yeong, Wai Yee; Wiria, Florencia Edith

    2016-03-01

    Additive manufacturing (AM), also commonly known as 3D printing, allows the direct fabrication of functional parts with complex shapes from digital models. In this review, the current progress of two AM processes suitable for metallic orthopaedic implant applications, namely selective laser melting (SLM) and electron beam melting (EBM) are presented. Several critical design factors such as the need for data acquisition for patient-specific design, design dependent porosity for osteo-inductive implants, surface topology of the implants and design for reduction of stress-shielding in implants are discussed. Additive manufactured biomaterials such as 316L stainless steel, titanium-6aluminium-4vanadium (Ti6Al4V) and cobalt-chromium (CoCr) are highlighted. Limitations and future potential of such technologies are also explored.

  16. Laser and electron-beam powder-bed additive manufacturing of metallic implants: A review on processes, materials and designs.

    PubMed

    Sing, Swee Leong; An, Jia; Yeong, Wai Yee; Wiria, Florencia Edith

    2016-03-01

    Additive manufacturing (AM), also commonly known as 3D printing, allows the direct fabrication of functional parts with complex shapes from digital models. In this review, the current progress of two AM processes suitable for metallic orthopaedic implant applications, namely selective laser melting (SLM) and electron beam melting (EBM) are presented. Several critical design factors such as the need for data acquisition for patient-specific design, design dependent porosity for osteo-inductive implants, surface topology of the implants and design for reduction of stress-shielding in implants are discussed. Additive manufactured biomaterials such as 316L stainless steel, titanium-6aluminium-4vanadium (Ti6Al4V) and cobalt-chromium (CoCr) are highlighted. Limitations and future potential of such technologies are also explored. PMID:26488900

  17. 77 FR 58911 - Additional Identifying Information for One (1) Individual Designated Pursuant to Executive Order...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-24

    ... Threaten to Disrupt the Middle East Peace Process'' (the ``Order''). DATES: The addition by the Director of... sanctions on persons who threaten to disrupt the Middle East peace process. The President identified in the... Middle East peace ] process; or (2) assist in, sponsor, or provide financial, material, or...

  18. Designing Location-Based Learning Experiences for People with Intellectual Disabilities and Additional Sensory Impairments

    ERIC Educational Resources Information Center

    Brown, David J.; McHugh, David; Standen, Penny; Evett, Lindsay; Shopland, Nick; Battersby, Steven

    2011-01-01

    The research reported here is part of a larger project which seeks to combine serious games (or games-based learning) with location-based services to help people with intellectual disabilities and additional sensory impairments to develop work based skills. Specifically this paper reports on where these approaches are combined to scaffold the…

  19. 77 FR 58382 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-20

    ... Special Exposure Cohort (SEC) under the Energy Employees Occupational Illness Compensation Program Act of... addition to the SEC: All employees of the Department of Energy, its predecessor agencies, and their... this class to the SEC or the result of any provision by Congress regarding the decision by HHS to...

  20. 78 FR 77686 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-24

    ... Exposure Cohort (SEC) under the Energy Employees Occupational Illness Compensation Program Act of 2000. On... SEC: All employees of the Department of Energy, its predecessor agencies, and their contractors and..., HHS will publish a notice in the Federal Register reporting the addition of this class to the SEC...

  1. 78 FR 64501 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-29

    ... Exposure Cohort (SEC) under the Energy Employees Occupational Illness Compensation Program Act of 2000. On... SEC: All employees of the Department of Energy, its predecessor agencies, and their contractors and... date, HHS will publish a notice in the Federal Register reporting the addition of this class to the...

  2. Additional F-Functions Useful for Preliminary Design of Shaped-Signature, Low-Boom, Supersonic-Cruise Aircraft

    NASA Technical Reports Server (NTRS)

    Mack, Robert J.

    1999-01-01

    Two additional low-boom F-functions have been described for use in designing low-boom, shaped-pressure-signature, supersonic-cruise aircraft. Based on the minimization studies of Seebass and George, the drag-nose shock strength trade-off modification of Darden, and the practical modification of Haglund, their use can aid in the design of conceptual low-boom aircraft, provide additional flexibility in the shaping of the low-boom aircraft nose section, and extend the applicability of shaped-pressure-signature methodology.

  3. Design of a Soil Science practical exercise to understand the soil carbon sequestration after biochar addition

    NASA Astrophysics Data System (ADS)

    Gascó, Gabriel; Cely, Paola; Saa-Requejo, Antonio; Mendez, Ana; Antón, Jose Manuel; Sánchez, Elena; Moratiel, Ruben; Tarquis, Ana M.

    2014-05-01

    The adaptation of the Universities to European Higher Education Area (EHEA) involves changes in the learning system. Students must obtain specific capabilities in the different degrees or masters. For example, in the degree of Agronomy at the Universidad Politécnica de Madrid (UPM, Spain), they must command Soil science, Mathematics or English. Sometimes, There is not a good communication between teachers and it causes that students do not understand the importance of the different subjects of a career. For this reason, teachers of the Soil Science and Mathematics Departments of the UPM designed a common practice to teach to the students the role of soil on the carbon sequestration. The objective of this paper is to explain the followed steps to the design of the practice. Acknowledgement to Universidad Politécnica de Madrid for the Projects in Education Innovation IE12_13-02009 and IE12_13-02012.

  4. 3D bipedal model with holonomic constraints for the decoupled optimal controller design of the biomechanical sit-to-stand maneuver.

    PubMed

    Mughal, Asif; Iqbal, Kamran

    2010-04-01

    Human voluntary movements are complex physical phenomena due to the complex control mechanism for coordination of limbs in the presence of physiological constraints. In this study, we propose a nonlinear human bipedal model with thirteen generalized coordinates to model sit-to-stand (STS) transfer. The model has three position based holonomic constraints and at the first stage, we decouple the translational variables (constrained system) from rotational variables (unconstrained systems). The unconstrained rotational degrees consist of seven sagittal and three frontal plane angles, which are controlled through their respective joint torques. We further decouple these angles in sagittal and frontal plane systems for a better control strategy. In this scheme, there are three decoupled controllers working together to stabilize the nonlinear model for a STS maneuver while satisfying the holonomic constraints. We adopt H(infinity) and H(2) controller designs for feedback torques in sagittal and frontal planes, respectively, and provide simulation results to show the improvement in the angular profiles. We further adopt this modeling strategy to study and analyze the neuromuscular disorders by decoupling healthy and neurodeficient extremities. Our study indicates that the decoupling of the bipedal model improves the controllability of the system and produces better angular profiles for a bipedal STS maneuver. This modeling scheme is useful for analysis of neuromuscular disorders and other relevant physiological motor control models. PMID:20387973

  5. Targeted gene addition into a specified location in the human genome using designed zinc finger nucleases

    PubMed Central

    Moehle, Erica A.; Rock, Jeremy M.; Lee, Ya-Li; Jouvenot, Yann; DeKelver, Russell C.; Gregory, Philip D.; Urnov, Fyodor D.; Holmes, Michael C.

    2007-01-01

    Efficient incorporation of novel DNA sequences into a specific site in the genome of living human cells remains a challenge despite its potential utility to genetic medicine, biotechnology, and basic research. We find that a precisely placed double-strand break induced by engineered zinc finger nucleases (ZFNs) can stimulate integration of long DNA stretches into a predetermined genomic location, resulting in high-efficiency site-specific gene addition. Using an extrachromosomal DNA donor carrying a 12-bp tag, a 900-bp ORF, or a 1.5-kb promoter-transcription unit flanked by locus-specific homology arms, we find targeted integration frequencies of 15%, 6%, and 5%, respectively, within 72 h of treatment, and with no selection for the desired event. Importantly, we find that the integration event occurs in a homology-directed manner and leads to the accurate reconstruction of the donor-specified genotype at the endogenous chromosomal locus, and hence presumably results from synthesis-dependent strand annealing repair of the break using the donor DNA as a template. This site-specific gene addition occurs with no measurable increase in the rate of random integration. Remarkably, we also find that ZFNs can drive the addition of an 8-kb sequence carrying three distinct promoter-transcription units into an endogenous locus at a frequency of 6%, also in the absence of any selection. These data reveal the surprising versatility of the specialized polymerase machinery involved in double-strand break repair, illuminate a powerful approach to mammalian cell engineering, and open the possibility of ZFN-driven gene addition therapy for human genetic disease. PMID:17360608

  6. Novel Overhang Support Designs for Powder-Based Electron Beam Additive Manufacturing (EBAM)

    NASA Technical Reports Server (NTRS)

    Nabors, Sammy A.

    2014-01-01

    NASA Marshall Space Flight Center, in collaboration with the University of Alabama, has developed a contact-free support structure used to fabricate overhang-type geometries via EBAM. The support structure is used for 3-D metal-printed components for the aerospace, automotive, biomedical and other industries. Current techniques use support structures to address deformation challenges inherent in 3-D metal printing. However, these structures (overhangs) are bonded to the component and need to be removed in post-processing using a mechanical tool. This new technology improves the overhang support structure design for components by eliminating associated geometric defects and post-processing requirements.

  7. 10 CFR 60.132 - Additional design criteria for surface facilities in the geologic repository operations area.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... the Geologic Repository Operations Area § 60.132 Additional design criteria for surface facilities in the geologic repository operations area. (a) Facilities for receipt and retrieval of waste. Surface... wastes at the geologic repository operations area, whether these wastes are on the surface...

  8. Testing for Additivity in Chemical Mixtures Using a Fixed-Ratio Ray Design and Statistical Equivalence Testing Methods

    EPA Science Inventory

    Fixed-ratio ray designs have been used for detecting and characterizing interactions of large numbers of chemicals in combination. Single chemical dose-response data are used to predict an “additivity curve” along an environmentally relevant ray. A “mixture curve” is estimated fr...

  9. 76 FR 72929 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-28

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF HEALTH AND HUMAN SERVICES Final Effect of Designation of a Class of Employees for Addition to the Special Exposure... Human Services (HHS). ACTION: Notice. SUMMARY: HHS gives notice concerning the final effect of the...

  10. 75 FR 27784 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-18

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Final Effect of Designation of a Class of Employees for Addition to the Special Exposure... Human Services (HHS). ACTION: Notice. SUMMARY: HHS gives notice concerning the final effect of...

  11. 75 FR 67364 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-02

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Final Effect of Designation of a Class of Employees for Addition to the Special Exposure... Human Services (HHS). ACTION: Notice. SUMMARY: HHS gives notice concerning the final effect of the...

  12. 75 FR 27785 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-18

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Final Effect of Designation of a Class of Employees for Addition to the Special Exposure... Human Services (HHS). ACTION: Notice. SUMMARY: HHS gives notice concerning the final effect of...

  13. 76 FR 34074 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-10

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Final Effect of Designation of a Class of Employees for Addition to the Special Exposure... Human Services (HHS). ACTION: Notice. SUMMARY: HHS gives notice concerning the final effect of the...

  14. 76 FR 7852 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-11

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Final Effect of Designation of a Class of Employees for Addition to the Special Exposure... Human Services (HHS). ACTION: Notice. SUMMARY: HHS gives notice concerning the final effect of the...

  15. 76 FR 59701 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-27

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Final Effect of Designation of a Class of Employees for Addition to the Special Exposure... Human Services (HHS). ACTION: Notice. SUMMARY: HHS gives notice concerning the final effect of the...

  16. 76 FR 33763 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-09

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Final Effect of Designation of a Class of Employees for Addition to the Special Exposure... Human Services (HHS). ACTION: Notice. SUMMARY: HHS gives notice concerning the final effect of the...

  17. 40 CFR 267.1103 - What additional design and operating standards apply if liquids will be in my containment building?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 27 2014-07-01 2014-07-01 false What additional design and operating standards apply if liquids will be in my containment building? 267.1103 Section 267.1103 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS FOR OWNERS...

  18. DETERMINING A ROBUST D-OPTIMAL DESIGN FOR TESTING FOR DEPARTURE FROM ADDITIVITY IN A MIXTURE OF FOUR PFAAS

    EPA Science Inventory

    Our objective was to determine an optimal experimental design for a mixture of perfluoroalkyl acids (PFAAs) that is robust to the assumption of additivity. Of particular focus to this research project is whether an environmentally relevant mixture of four PFAAs with long half-liv...

  19. Determining a Robust D-Optimal Design for Testing for Departure from Additivity in a Mixture of Four Perfluoroalkyl Acids.

    EPA Science Inventory

    Our objective is to determine an optimal experimental design for a mixture of perfluoroalkyl acids (PFAAs) that is robust to the assumption of additivity. PFAAs are widely used in consumer products and industrial applications. The presence and persistence of PFAAs, especially in ...

  20. 78 FR 3897 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-17

    ... Cohort AGENCY: National Institute for Occupational Safety and Health (NIOSH), Centers for Disease Control... notice concerning the final effect of the HHS decision to designate a class of employees from the Nuclear... employees as an addition to the SEC: All Atomic Weapons Employees who worked at the facility owned...

  1. Additional testing of the inlets designed for a tandem fan V/STOL nacelle

    NASA Technical Reports Server (NTRS)

    Ybarra, A. H.

    1981-01-01

    The wind tunnel testing of a scale model of a tandem fan nacelle designed for a type (subsonic cruise) V/STOL aircraft configuration is discussed. The performance for the isolated front inlet and for the combined front and aft inlets is reported. Model variables include front and aft inlets with aft inlet variations of short and long aft inlet cowls, with a shaft simulator and diffuser vortex generators, cowl lip fillets, and nacelle strakes. Inlet pressure recovery, distortion, and inlet angle-to-attack separation limits were evaluated at tunnel velocity from 0 to 240 knots, angles-of-attack from -10 to +40 degrees and inlet flow rates corresponding to throat Mach number from 0.0 to 0.6. Combined nacelle pitch and yaw runs up to 30 deg. were also made.

  2. Disentangling Robust Developmental Constraints from the Instructionally Mutable: Young Children's Epistemic Reasoning about a Study of Their Own Design

    ERIC Educational Resources Information Center

    Metz, Kathleen E.

    2011-01-01

    This study examines first graders' epistemic reasoning, in tacit "practical epistemologies" reflected in thinking about an investigation of their own design. I analyzed children's epistemic reasoning, following a design experiment scaffolding increasing regulation of scientific inquiry in a domain they studied in depth. Participants consisted of…

  3. 75 FR 3469 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-21

    ...The Department of Health and Human Services (HHS) gives notice concerning the final effect of the HHS decision to designate a class of employees at the Hanford site in Richland, Washington, as an addition to the Special Exposure Cohort (SEC) under the Energy Employees Occupational Illness Compensation Program Act of 2000. On December 10, 2009, as provided for under 42 U.S.C. 7384q(b), the......

  4. The photogrammetric inner constraints

    NASA Astrophysics Data System (ADS)

    Dermanis, Athanasios

    A derivation of the complete inner constraints, which are required for obtaining "free network" solutions in close-range photogrammetry, is presented. The inner constraints are derived analytically for the bundle method, by exploiting the fact that the rows of their coefficient matrix from a basis for the null subspace of the design matrix used in the linearized observation equations. The derivation is independent of any particular choice of rotational parameters and examples are given for three types of rotation angles used in photogrammetry, as well as for the Rodriguez elements. A convenient algorithm based on the use of the S-transformation is presented, for the computation of free solutions with either inner or partial inner constraints. This approach is finally compared with alternative approaches to free network solutions.

  5. Constraint algebra in bigravity

    SciTech Connect

    Soloviev, V. O.

    2015-07-15

    The number of degrees of freedom in bigravity theory is found for a potential of general form and also for the potential proposed by de Rham, Gabadadze, and Tolley (dRGT). This aim is pursued via constructing a Hamiltonian formalismand studying the Poisson algebra of constraints. A general potential leads to a theory featuring four first-class constraints generated by general covariance. The vanishing of the respective Hessian is a crucial property of the dRGT potential, and this leads to the appearance of two additional second-class constraints and, hence, to the exclusion of a superfluous degree of freedom—that is, the Boulware—Deser ghost. The use of a method that permits avoiding an explicit expression for the dRGT potential is a distinctive feature of the present study.

  6. Constraint algebra in bigravity

    NASA Astrophysics Data System (ADS)

    Soloviev, V. O.

    2015-07-01

    The number of degrees of freedom in bigravity theory is found for a potential of general form and also for the potential proposed by de Rham, Gabadadze, and Tolley (dRGT). This aim is pursued via constructing a Hamiltonian formalismand studying the Poisson algebra of constraints. A general potential leads to a theory featuring four first-class constraints generated by general covariance. The vanishing of the respective Hessian is a crucial property of the dRGT potential, and this leads to the appearance of two additional second-class constraints and, hence, to the exclusion of a superfluous degree of freedom—that is, the Boulware—Deser ghost. The use of a method that permits avoiding an explicit expression for the dRGT potential is a distinctive feature of the present study.

  7. Joint design of kT-points trajectories and RF pulses under explicit SAR and power constraints in the large flip angle regime

    NASA Astrophysics Data System (ADS)

    Gras, Vincent; Luong, Michel; Amadon, Alexis; Boulant, Nicolas

    2015-12-01

    In Magnetic Resonance Imaging at ultra-high field, kT-points radiofrequency pulses combined with parallel transmission are a promising technique to mitigate the B1 field inhomogeneity in 3D imaging applications. The optimization of the corresponding k-space trajectory for its slice-selective counterpart, i.e. the spokes method, has been shown in various studies to be very valuable but also dependent on the hardware and specific absorption rate constraints. Due to the larger number of degrees of freedom than for spokes excitations, joint design techniques based on the fine discretization (gridding) of the parameter space become hardly tractable for kT-points pulses. In this article, we thus investigate the simultaneous optimization of the 3D blipped k-space trajectory and of the kT-points RF pulses, using a magnitude least squares cost-function, with explicit constraints and in the large flip angle regime. A second-order active-set algorithm is employed due to its demonstrated success and robustness in similar problems. An analysis of global optimality and of the structure of the returned trajectories is proposed. The improvement provided by the k-space trajectory optimization is validated experimentally by measuring the flip angle on a spherical water phantom at 7T and via Quantum Process Tomography.

  8. Designing Energy Supply Chains with the P-Graph Framework under Cost Constraints andSustainability Considerations

    EPA Science Inventory

    A computer-aided methodology for designing sustainable supply chains is presented using the P-graph framework to develop supply chain structures which are analyzed using cost, the cost of producing electricity, and two sustainability metrics: ecological footprint and emergy. They...

  9. Effect of low-addition soft contact lenses with decentered optical design on myopia progression in children: a pilot study

    PubMed Central

    Fujikado, Takashi; Ninomiya, Sayuri; Kobayashi, Takuma; Suzaki, Asaki; Nakada, Mitsuhiko; Nishida, Kohji

    2014-01-01

    Purpose To investigate the effect of low-addition soft contact lenses (CLs) with decentered optical design on the progression of myopia in children in a pilot study. Subjects and methods Twenty-four Japanese children age 10–16 years with baseline myopia of −0.75 to −3.50 D sphere and ≤1.00 D cylinder were studied. The new CLs were designed to have a nasal decentration with the optical center centered on the line of sight, and with progressive-addition power of +0.5 D peripherally. Monofocal soft CLs were used as controls. A pair of new CLs or control CLs was randomly assigned to the children, and they wore the lenses for 12 months during the first phase. Then, the type of CLs was changed, ie, a crossover design, and the children were observed for another 12 months during the second phase. The end points were changes in axial length and refractive error (spherical equivalent) under cycloplegia. Results The change of axial length in the new-CL and control-CL groups was not different between 12 months and baseline, the change of axial length between 12 months and 1 month in the new-CL group (0.09±0.08 mm) was significantly smaller (47%) than that in the control-CL group (0.17±0.08 mm, P<0.05). During the same period, the change of refractive error in the new-CL group was not significantly different from that in the control group. Neither the change in axial length nor refractive error in the new-CL group was significantly different from those in the control-CL group in the second phase. Conclusion This pilot study suggests that low-addition soft CLs with decentered optical design can reduce the degree of axial elongation in myopic children after an initial transient phase of CL wear. The reduction of the progression of myopia by low-addition soft CLs warrants further investigations. PMID:25284981

  10. Effect of Additives on Green Sand Molding Properties using Design of Experiments and Taguchi's Quality Loss Function - An Experimental Study

    NASA Astrophysics Data System (ADS)

    Desai, Bhagyashree; Mokashi, Pavani; Anand, R. L.; Burli, S. B.; Khandal, S. V.

    2016-09-01

    The experimental study aims to underseek the effect of various additives on the green sand molding properties as a particular combination of additives could yield desired sand properties. The input parameters (factors) selected were water and powder (Fly ash, Coconut shell and Tamarind) in three levels. Experiments were planned using design of experiments (DOE). On the basis of plans, experiments were conducted to understand the behavior of sand mould properties such as compression strength, shear strength, permeability number with various additives. From the experimental results it could be concluded that the factors have significant effect on the sand properties as P-value found to be less than 0.05 for all the cases studied. The optimization based on quality loss function was also performed. The study revealed that the quality loss associated with the tamarind powder was lesser compared to other additives selected for the study. The optimization based on quality loss function and the parametric analysis using ANOVA suggested that the tamarind powder of 8 gm per Kg of molding sand and moisture content of 7% yield better properties to obtain sound castings.

  11. Some design constraints required for the assembly of software components: The incorporation of atomic abstract types into generically structured abstract types

    NASA Technical Reports Server (NTRS)

    Johnson, Charles S.

    1986-01-01

    It is nearly axiomatic, that to take the greatest advantage of the useful features available in a development system, and to avoid the negative interactions of those features, requires the exercise of a design methodology which constrains their use. A major design support feature of the Ada language is abstraction: for data, functions processes, resources, and system elements in general. Atomic abstract types can be created in packages defining those private types and all of the overloaded operators, functions, and hidden data required for their use in an application. Generically structured abstract types can be created in generic packages defining those structured private types, as buildups from the user-defined data types which are input as parameters. A study is made of the design constraints required for software incorporating either atomic or generically structured abstract types, if the integration of software components based on them is to be subsequently performed. The impact of these techniques on the reusability of software and the creation of project-specific software support environments is also discussed.

  12. Impediments and constraints in the uptake of water sensitive urban design measures in greenfield and infill developments.

    PubMed

    Sharma, Ashok K; Cook, Stephen; Tjandraatmadja, Grace; Gregory, Alan

    2012-01-01

    Water sensitive urban developments are designed with integrated urban water management concepts and water sensitive urban design measures. The initiatives that may be included are the substitution of imported drinking water with alternative sources using a fit-for-purpose approach and structural and non-structural measures for the source control of stormwater. A water sensitive approach to urban development can help in achieving sustainability objectives by minimising disturbance to ecological and hydrological processes, and also relieve stress on conventional water systems. Water sensitive urban developments remain novel in comparison with conventional approaches, so the understanding and knowledge of the systems in regards to their planning; design; implementation; operation and maintenance; health impacts and environmental impacts is still developing and thus the mainstream uptake of these approaches faces many challenges. A study has been conducted to understand these challenges through a detailed literature review, investigating a large number of local greenfield and infill developments, and conducting extensive consultation with water professionals. This research has identified the social, economic, political, institutional and technological challenges faced in implementing water sensitive urban design in greenfield and infill developments. The research found in particular that there is the need for long-term monitoring studies of water sensitive urban developments. This monitoring is important to validate the performance of novel approaches implemented and improve associated guidelines, standards, and regulatory and governance frameworks, which can lead to mainstream acceptance of water sensitive urban development approaches. The dissemination of this research will help generate awareness among water professionals, water utilities, developers, planners and regulators of the research challenges to be addressed in order to achieve more mainstream acceptance of

  13. Optimal design of an electro-hydraulic valve for heavy-duty vehicle clutch actuator with certain constraints

    NASA Astrophysics Data System (ADS)

    Meng, Fei; Shi, Peng; Karimi, Hamid Reza; Zhang, Hui

    2016-02-01

    The main objective of this paper is to investigate the sensitivity analysis and optimal design of a proportional solenoid valve (PSV) operated pressure reducing valve (PRV) for heavy-duty automatic transmission clutch actuators. The nonlinear electro-hydraulic valve model is developed based on fluid dynamics. In order to implement the sensitivity analysis and optimization for the PRV, the PSV model is validated by comparing the results with data obtained from a real test-bench. The sensitivity of the PSV pressure response with regard to the structural parameters is investigated by using Sobol's method. Finally, simulations and experimental investigations are performed on the optimized prototype and the results reveal that the dynamical characteristics of the valve have been improved in comparison with the original valve.

  14. A review of wireless-photonic systems: Design methodologies and topologies, constraints, challenges, and innovations in electronics and photonics

    NASA Astrophysics Data System (ADS)

    Farsaei, Ahmadreza; Wang, Yun; Molavi, Reza; Jayatilleka, Hasitha; Caverley, Michael; Beikahmadi, Mohammad; Masnadi Shirazi, Amir Hossein; Jaeger, Nicolas; Chrostowski, Lukas; Mirabbasi, Shahriar

    2016-08-01

    Photonic networks form the backbone for data communications. In particular, in current and future wireless communication systems, photonic networks are becoming increasingly popular for data distribution between the central office and the remote antenna units at base stations. As wireless-photonic systems become in increasing demand, low-cost implementation of such systems will be desirable. This paper describes how integrated photonics and electronics, on silicon, can be used to design such systems. Various building blocks of such silicon-photonics systems are reviewed. The emphasis is on a 60 GHz wireless system which could be suitable for the emerging 5th-generation (5G) cellular networks. The implementation discussed here uses digital baseband optical transmission as opposed to the radio-over-fibre approach.

  15. Additive manufacturing and mechanical characterization of graded porosity scaffolds designed based on triply periodic minimal surface architectures.

    PubMed

    Afshar, M; Anaraki, A Pourkamali; Montazerian, H; Kadkhodapour, J

    2016-09-01

    Since the advent of additive manufacturing techniques, triply periodic minimal surfaces have emerged as a novel tool for designing porous scaffolds. Whereas scaffolds are expected to provide multifunctional performance, spatially changing pore patterns have been a promising approach to integrate mechanical characteristics of different architectures into a unique scaffold. Smooth morphological variations are also frequently seen in nature particularly in bone and cartilage structures and can be inspiring for designing of artificial tissues. In this study, we carried out experimental and numerical procedures to uncover the mechanical properties and deformation mechanisms of linearly graded porosity scaffolds for two different mathematically defined pore structures. Among TPMS-based scaffolds, P and D surfaces were subjected to gradient modeling to explore the mechanical responses for stretching and bending dominated deformations, respectively. Moreover, the results were compared to their corresponding uniform porosity structures. Mechanical properties were found to be by far greater for the stretching dominated structure (P-Surface). For bending dominated architecture (D-Surface), although there was no global fracture for uniform structures, graded structure showed a brittle fracture at 0.08 strain. A layer by layer deformation mechanism for stretching dominated structure was observed. For bending dominated scaffolds, deformation was accompanied by development of 45° shearing bands. Finite element simulations were also performed and the results showed a good agreement with the experimental observations.

  16. Additive manufacturing and mechanical characterization of graded porosity scaffolds designed based on triply periodic minimal surface architectures.

    PubMed

    Afshar, M; Anaraki, A Pourkamali; Montazerian, H; Kadkhodapour, J

    2016-09-01

    Since the advent of additive manufacturing techniques, triply periodic minimal surfaces have emerged as a novel tool for designing porous scaffolds. Whereas scaffolds are expected to provide multifunctional performance, spatially changing pore patterns have been a promising approach to integrate mechanical characteristics of different architectures into a unique scaffold. Smooth morphological variations are also frequently seen in nature particularly in bone and cartilage structures and can be inspiring for designing of artificial tissues. In this study, we carried out experimental and numerical procedures to uncover the mechanical properties and deformation mechanisms of linearly graded porosity scaffolds for two different mathematically defined pore structures. Among TPMS-based scaffolds, P and D surfaces were subjected to gradient modeling to explore the mechanical responses for stretching and bending dominated deformations, respectively. Moreover, the results were compared to their corresponding uniform porosity structures. Mechanical properties were found to be by far greater for the stretching dominated structure (P-Surface). For bending dominated architecture (D-Surface), although there was no global fracture for uniform structures, graded structure showed a brittle fracture at 0.08 strain. A layer by layer deformation mechanism for stretching dominated structure was observed. For bending dominated scaffolds, deformation was accompanied by development of 45° shearing bands. Finite element simulations were also performed and the results showed a good agreement with the experimental observations. PMID:27281165

  17. Estimation of a partially linear additive model for data from an outcome-dependent sampling design with a continuous outcome.

    PubMed

    Tan, Ziwen; Qin, Guoyou; Zhou, Haibo

    2016-10-01

    Outcome-dependent sampling (ODS) designs have been well recognized as a cost-effective way to enhance study efficiency in both statistical literature and biomedical and epidemiologic studies. A partially linear additive model (PLAM) is widely applied in real problems because it allows for a flexible specification of the dependence of the response on some covariates in a linear fashion and other covariates in a nonlinear non-parametric fashion. Motivated by an epidemiological study investigating the effect of prenatal polychlorinated biphenyls exposure on children's intelligence quotient (IQ) at age 7 years, we propose a PLAM in this article to investigate a more flexible non-parametric inference on the relationships among the response and covariates under the ODS scheme. We propose the estimation method and establish the asymptotic properties of the proposed estimator. Simulation studies are conducted to show the improved efficiency of the proposed ODS estimator for PLAM compared with that from a traditional simple random sampling design with the same sample size. The data of the above-mentioned study is analyzed to illustrate the proposed method.

  18. Estimation of a partially linear additive model for data from an outcome-dependent sampling design with a continuous outcome.

    PubMed

    Tan, Ziwen; Qin, Guoyou; Zhou, Haibo

    2016-10-01

    Outcome-dependent sampling (ODS) designs have been well recognized as a cost-effective way to enhance study efficiency in both statistical literature and biomedical and epidemiologic studies. A partially linear additive model (PLAM) is widely applied in real problems because it allows for a flexible specification of the dependence of the response on some covariates in a linear fashion and other covariates in a nonlinear non-parametric fashion. Motivated by an epidemiological study investigating the effect of prenatal polychlorinated biphenyls exposure on children's intelligence quotient (IQ) at age 7 years, we propose a PLAM in this article to investigate a more flexible non-parametric inference on the relationships among the response and covariates under the ODS scheme. We propose the estimation method and establish the asymptotic properties of the proposed estimator. Simulation studies are conducted to show the improved efficiency of the proposed ODS estimator for PLAM compared with that from a traditional simple random sampling design with the same sample size. The data of the above-mentioned study is analyzed to illustrate the proposed method. PMID:27006375

  19. Integrated Autopilot/Autothrottle Based on a Total Energy Control Concept: Design and Evaluation of Additional Autopilot Modes

    NASA Technical Reports Server (NTRS)

    Bruce, Kevin R.

    1988-01-01

    An integrated autopilot/autothrottle system was designed using a total energy control design philosophy. This design ensures that the system can differentiate between maneuvers requiring a change in thrust to accomplish a net energy change, and those maneuvers which only require elevator control to redistribute energy. The system design, the development of the system, and a summary of simulation results are defined.

  20. Additive effects on the improvement of insecticidal activity: Design, synthesis, and insecticidal activity of novel pymetrozine derivatives.

    PubMed

    Yang, Yan; Liu, Yuxiu; Song, Hongjian; Li, Yongqiang; Wang, Qingmin

    2016-02-01

    A series of new pymetrozine analogues containing both methyl on the imine carbon and phenoxy group at the pyridine ring were designed and synthesized. Their insecticidal activities against bean aphid (Aphis craccivora), mosquito larvae (Culex pipiens pallens), cotton bollworm (Helicoverpa armigera), corn borer (Ostrinia nubilalis) and oriental armyworm (Mythimna separata) were evaluated. The results of bioassays indicated that most of the target compounds showed good insecticidal activity against bean aphid; especially, IIIf (80%) and IIIl (80%) exhibited higher aphicidal activity than pymetrozine (30%) at 5mg/kg, and the two compounds still showed 20% and 30% mortality at 2.5mg/kg, respectively, whereas pymetrozine displayed no activity at the same concentration. These compounds exhibited a completely different structure-activity relationship to that of known pymetrozine derivatives, in which it is thought introducing alkyl group on the imine carbon could be detrimental to the activities. Our new result suggested that the methyl on the imine carbon and phenoxy group at the pyridine ring of phenoxy group may play additive effects on the improvement of aphicidal activity. Besides this, compound IIIs, containing an allyl at the para position of phenoxy group, exhibited excellent insecticidal activity against mosquito larvae, lepidoptera pests cotton bollworm, corn borer and oriental armyworm. PMID:26342545

  1. Superresolution via sparsity constraints

    NASA Technical Reports Server (NTRS)

    Donoho, David L.

    1992-01-01

    The problem of recovering a measure mu supported on a lattice of span Delta is considered under the condition that measurements are only available concerning the Fourier Transform at frequencies of Omega or less. If Omega is much smaller than the Nyquist frequency pi/Delta and the measurements are noisy, then stable recovery of mu is generally impossible. It is shown here that if, in addition, it is known that mu satisfies certain sparsity constraints, then stable recovery is possible. This finding validates practical efforts in spectroscopy, seismic prospecting, and astronomy to provide superresolution by imposing support limitations in reconstruction.

  2. D-OPTIMAL EXPERIMENTAL DESIGNS TO TEST FOR DEPARTURE FROM ADDITIVITY IN A FIXED-RATIO MIXTURE RAY.

    EPA Science Inventory

    Traditional factorial designs for evaluating interactions among chemicals in a mixture are prohibitive when the number of chemicals is large. However, recent advances in statistically-based experimental design have made it easier to evaluate interactions involving many chemicals...

  3. 75 FR 81716 - Additional Designation Pursuant to Executive Order 13469 of July 25, 2008 “Blocking Property of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-28

    ... ``Blocking Property of Additional Persons Undermining Democratic Processes or Institutions in Zimbabwe... ``Blocking Property of Additional Persons Undermining Democratic Processes or Institutions in Zimbabwe'' (the... issued Executive Order 13469 with respect to Zimbabwe pursuant to, inter alia, the...

  4. 40 CFR 267.1103 - What additional design and operating standards apply if liquids will be in my containment building?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... the migration of hazardous constituents into the barrier (for example, a geomembrane covered by a... containment system, including a secondary barrier designed and constructed to prevent migration of...

  5. 76 FR 33762 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-09

    ... decision to designate a class of employees from Vitro Manufacturing, Canonsburg, Pennsylvania, as an... who worked at Vitro Manufacturing in Canonsburg, Pennsylvania, from January 1, 1958 through...

  6. 76 FR 72928 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-28

    ... decision to designate a class of employees from Vitro Manufacturing in Canonsburg, Pennsylvania, as an... worked at Vitro Manufacturing in Canonsburg, Pennsylvania, from January 1, 1960 through September...

  7. 40 CFR 267.1103 - What additional design and operating standards apply if liquids will be in my containment building?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... the migration of hazardous constituents into the barrier (for example, a geomembrane covered by a... containment system, including a secondary barrier designed and constructed to prevent migration of...

  8. 40 CFR 267.1103 - What additional design and operating standards apply if liquids will be in my containment building?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... the migration of hazardous constituents into the barrier (for example, a geomembrane covered by a... containment system, including a secondary barrier designed and constructed to prevent migration of...

  9. 77 FR 5254 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-02

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institute for Occupational Safety and Health Final Effect of Designation of a...: HHS gives notice concerning the final effect of the HHS decision to designate a class of...

  10. 75 FR 51817 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-23

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institute for Occupational Safety and Health Final Effect of Designation of a...: HHS gives notice concerning the final effect of the HHS decision to designate a class of...

  11. 75 FR 51816 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-23

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institute for Occupational Safety and Health Final Effect of Designation of a...: HHS gives notice concerning the final effect of the HHS decision to designate a class of...

  12. 10 CFR 60.132 - Additional design criteria for surface facilities in the geologic repository operations area.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...) DISPOSAL OF HIGH-LEVEL RADIOACTIVE WASTES IN GEOLOGIC REPOSITORIES Technical Criteria Design Criteria for... periodically tested. (d) Waste treatment. Radioactive waste treatment facilities shall be designed to process any radioactive wastes generated at the geologic repository operations area into a form suitable...

  13. 10 CFR 60.132 - Additional design criteria for surface facilities in the geologic repository operations area.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...) DISPOSAL OF HIGH-LEVEL RADIOACTIVE WASTES IN GEOLOGIC REPOSITORIES Technical Criteria Design Criteria for... periodically tested. (d) Waste treatment. Radioactive waste treatment facilities shall be designed to process any radioactive wastes generated at the geologic repository operations area into a form suitable...

  14. 10 CFR 60.132 - Additional design criteria for surface facilities in the geologic repository operations area.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...) DISPOSAL OF HIGH-LEVEL RADIOACTIVE WASTES IN GEOLOGIC REPOSITORIES Technical Criteria Design Criteria for... periodically tested. (d) Waste treatment. Radioactive waste treatment facilities shall be designed to process any radioactive wastes generated at the geologic repository operations area into a form suitable...

  15. 10 CFR 60.132 - Additional design criteria for surface facilities in the geologic repository operations area.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...) DISPOSAL OF HIGH-LEVEL RADIOACTIVE WASTES IN GEOLOGIC REPOSITORIES Technical Criteria Design Criteria for... periodically tested. (d) Waste treatment. Radioactive waste treatment facilities shall be designed to process any radioactive wastes generated at the geologic repository operations area into a form suitable...

  16. Performance of portland limestone cements: Cements designed to be more sustainable that include up to 15% limestone addition

    NASA Astrophysics Data System (ADS)

    Barrett, Timothy J.

    In 2009, ASTM and AASHTO permitted the use of up to 5% interground limestone in ordinary portland cement (OPC) as a part of a change to ASTM C150/AASHTO M85. When this work was initiated a new proposal was being discussed that would enable up to 15% interground limestone cement to be considered in ASTM C595/AASHTO M234. This work served to provide rapid feedback to the state department of transportation and concrete industry for use in discussions regarding these specifications. Since the time this work was initiated, ASTM C595/AASHTO M234 was passed (2012c) and PLCs are now able to be specified, however they are still not widely used. The proposal for increasing the volume of limestone that would be permitted to be interground in cement is designed to enable more sustainable construction, which may significantly reduce the CO2 that is embodied in the built infrastructure while also extending the life of cement quarries. Research regarding the performance of cements with interground limestone has been conducted by the cement industry since these cements became widely used in Europe over three decades ago, however this work focuses on North American Portland Limestone Cements (PLCs) which are specifically designed to achieve similar performance as the OPCs they replace.This thesis presents a two-phase study in which the potential for application of cements containing limestone was assessed. The first phase of this study utilized a fundamental approach to determine whether cement with up to 15% of interground or blended limestone can be used as a direct substitute to ordinary portland cement. The second phase of the study assessed the concern of early age shrinkage and cracking potential when using PLCs, as these cements are typically ground finer than their OPC counterparts. For the first phase of the study, three commercially produced PLCs were obtained and compared to three commercially produced OPCs made from the same clinker. An additional cement was tested

  17. Performance of portland limestone cements: Cements designed to be more sustainable that include up to 15% limestone addition

    NASA Astrophysics Data System (ADS)

    Barrett, Timothy J.

    In 2009, ASTM and AASHTO permitted the use of up to 5% interground limestone in ordinary portland cement (OPC) as a part of a change to ASTM C150/AASHTO M85. When this work was initiated a new proposal was being discussed that would enable up to 15% interground limestone cement to be considered in ASTM C595/AASHTO M234. This work served to provide rapid feedback to the state department of transportation and concrete industry for use in discussions regarding these specifications. Since the time this work was initiated, ASTM C595/AASHTO M234 was passed (2012c) and PLCs are now able to be specified, however they are still not widely used. The proposal for increasing the volume of limestone that would be permitted to be interground in cement is designed to enable more sustainable construction, which may significantly reduce the CO2 that is embodied in the built infrastructure while also extending the life of cement quarries. Research regarding the performance of cements with interground limestone has been conducted by the cement industry since these cements became widely used in Europe over three decades ago, however this work focuses on North American Portland Limestone Cements (PLCs) which are specifically designed to achieve similar performance as the OPCs they replace.This thesis presents a two-phase study in which the potential for application of cements containing limestone was assessed. The first phase of this study utilized a fundamental approach to determine whether cement with up to 15% of interground or blended limestone can be used as a direct substitute to ordinary portland cement. The second phase of the study assessed the concern of early age shrinkage and cracking potential when using PLCs, as these cements are typically ground finer than their OPC counterparts. For the first phase of the study, three commercially produced PLCs were obtained and compared to three commercially produced OPCs made from the same clinker. An additional cement was tested

  18. 76 FR 33762 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-09

    ... decision to designate a class of employees from the Linde Ceramics Plant in Tonawanda, New York, as an... worked at the Linde Ceramics Plant in Tonawanda, New York, from January 1, 1954 through December 31,...

  19. 76 FR 72928 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-28

    ... decision to designate a class of employees from W.R. Grace and Company in Curtis Bay, Maryland, as an... worked at any building or area at the facility owned by W.R. Grace and Company in Curtis Bay,...

  20. D-OPTIMAL EXPERIMENTAL DESIGNS TO TEST FOR DEPARTURE FROM ADDITIVITY IN A FIXED-RATIO RAY MIXTURE.

    EPA Science Inventory

    Risk assessors are becoming increasingly aware of the importance of assessing interactions between chemicals in a mixture. Most traditional designs for evaluating interactions are prohibitive when the number of chemicals in the mixture is large. However, evaluation of interacti...

  1. Data assimilation with inequality constraints

    NASA Astrophysics Data System (ADS)

    Thacker, W. C.

    If values of variables in a numerical model are limited to specified ranges, these restrictions should be enforced when data are assimilated. The simplest option is to assimilate without regard for constraints and then to correct any violations without worrying about additional corrections implied by correlated errors. This paper addresses the incorporation of inequality constraints into the standard variational framework of optimal interpolation with emphasis on our limited knowledge of the underlying probability distributions. Simple examples involving only two or three variables are used to illustrate graphically how active constraints can be treated as error-free data when background errors obey a truncated multi-normal distribution. Using Lagrange multipliers, the formalism is expanded to encompass the active constraints. Two algorithms are presented, both relying on a solution ignoring the inequality constraints to discover violations to be enforced. While explicitly enforcing a subset can, via correlations, correct the others, pragmatism based on our poor knowledge of the underlying probability distributions suggests the expedient of enforcing them all explicitly to avoid the computationally expensive task of determining the minimum active set. If additional violations are encountered with these solutions, the process can be repeated. Simple examples are used to illustrate the algorithms and to examine the nature of the corrections implied by correlated errors.

  2. 75 FR 9645 - Additional Designations of Individuals and Entities Pursuant to Section 804(b) of the Foreign...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-03

    ... Act. The list of additional designees is as follows: Individuals 1. MENDEZ VARGAS, Jose de Jesus (a.k...; a.k.a. MENDEZ VARGAS, Jesus; a.k.a. MENDEZ, Jesus), Tazumbos, Jalisco, Mexico; Calle Dr. Lose...

  3. 77 FR 15759 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-16

    ... Ceramics Plant in Tonawanda, New York, as an addition to the Special Exposure Cohort (SEC) under the Energy... to the SEC: All Atomic Weapons Employees who worked in any area at the Linde Ceramics Plant...

  4. 77 FR 60437 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-03

    ... Clarksville Modification Center Site, Ft. Campbell, in Clarksville, Tennessee, as an addition to the Special.... Campbell, in Clarksville, Tennessee, from August 1, 1949, through December 31, 1967, for a number of...

  5. 75 FR 51816 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-23

    ... from the Mound Plant in Miamisburg, Ohio, as an addition to the Special Exposure Cohort (SEC) under the... contractors and subcontractors who had at least one tritium bioassay sample and worked at the Mound Plant...

  6. Constraint monitoring in TOSCA

    NASA Technical Reports Server (NTRS)

    Beck, Howard

    1992-01-01

    The Job-Shop Scheduling Problem (JSSP) deals with the allocation of resources over time to factory operations. Allocations are subject to various constraints (e.g., production precedence relationships, factory capacity constraints, and limits on the allowable number of machine setups) which must be satisfied for a schedule to be valid. The identification of constraint violations and the monitoring of constraint threats plays a vital role in schedule generation in terms of the following: (1) directing the scheduling process; and (2) informing scheduling decisions. This paper describes a general mechanism for identifying constraint violations and monitoring threats to the satisfaction of constraints throughout schedule generation.

  7. Integrity Constraint Monitoring in Software Development: Proposed Architectures

    NASA Technical Reports Server (NTRS)

    Fernandez, Francisco G.

    1997-01-01

    In the development of complex software systems, designers are required to obtain from many sources and manage vast amounts of knowledge of the system being built and communicate this information to personnel with a variety of backgrounds. Knowledge concerning the properties of the system, including the structure of, relationships between and limitations of the data objects in the system, becomes increasingly more vital as the complexity of the system and the number of knowledge sources increases. Ensuring that violations of these properties do not occur becomes steadily more challenging. One approach toward managing the enforcement or system properties, called context monitoring, uses a centralized repository of integrity constraints and a constraint satisfiability mechanism for dynamic verification of property enforcement during program execution. The focus of this paper is to describe possible software architectures that define a mechanism for dynamically checking the satisfiability of a set of constraints on a program. The next section describes the context monitoring approach in general. Section 3 gives an overview of the work currently being done toward the addition of an integrity constraint satisfiability mechanism to a high-level program language, SequenceL, and demonstrates how this model is being examined to develop a general software architecture. Section 4 describes possible architectures for a general constraint satisfiability mechanism, as well as an alternative approach that, uses embedded database queries in lieu of an external monitor. The paper concludes with a brief summary outlining the, current state of the research and future work.

  8. 76 FR 47646 - Additional Designation of Person Whose Property and Interests in Property Are Blocked Pursuant to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-05

    ... Persons Contributing to the Conflict in Somalia.'' AGENCY: Office of Foreign Assets Control, Treasury... in Somalia.'' DATES: The designation by the Director of OFAC of the individual identified in this... to the Conflict in Somalia'' (the ``Order''), pursuant to, inter alia, the International...

  9. 76 FR 47647 - Additional Designation of Person Whose Property and Interests in Property Are Blocked Pursuant to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-05

    ... Persons Contributing to the Conflict in Somalia.'' AGENCY: Office of Foreign Assets Control, Treasury... in Somalia.'' DATES: The designation by the Director of OFAC of the individual identified in this... to the Conflict in Somalia'' (the ``Order''), pursuant to, inter alia, the International...

  10. 77 FR 65310 - Additional Air Quality Designations for the 2006 24-Hour Fine Particle National Ambient Air...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-26

    ... the 2006 24-hour Fine Particle (PM 2.5 ) National Ambient Air Quality Standards,'' 74 FR 58688... Federal Regulations DC District of Columbia EO Executive Order EPA Environmental Protection Agency FR... EPA finalized designations for the 2006 24-hour PM 2.5 NAAQS (74 FR 58688, November 13, 2009), the...

  11. 40 CFR 267.1103 - What additional design and operating standards apply if liquids will be in my containment building?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... appropriate means, you must include: (a) A primary barrier designed and constructed of materials to prevent...) Constructed of a granular drainage material with a hydraulic conductivity of 1 × 10− 2 cm/sec or more and a thickness of 12 inches (30.5 cm) or more, or constructed of synthetic or geonet drainage materials with...

  12. 76 FR 6056 - Additional Air Quality Designations for the 2006 24-Hour Fine Particle National Ambient Air...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-03

    ... Protection Agency FR Federal Register NAAQS National Ambient Air Quality Standards NTTAA National Technology... (74 FR 58688), EPA deferred designations for three areas to evaluate further the reason for their high... November 13, 2009 notice (74 FR 58688), we also announced that our review of 2006-2008 monitoring data...

  13. 75 FR 3470 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-21

    ... Cohort AGENCY: National Institute for Occupational Safety and Health (NIOSH), Department of Health and... and Controls Corp. in Attleboro, Massachusetts, as an addition to the Special Exposure Cohort (SEC) under the Energy Employees Occupational Illness Compensation Program Act of 2000. On December 10,...

  14. 75 FR 3469 - Final Effect of Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-21

    ... Hospital in Oak Ridge, Tennessee, as an addition to the Special Exposure Cohort (SEC) under the Energy... and subcontractors who worked in any location at the Oak Ridge Hospital in Oak Ridge, Tennessee, from May 15, 1950 through December 31, 1959, for a number of work days aggregating at least 250 work...

  15. Asymmetric Homoenolate Additions to Acyl Phosphonates through Rational Design of a Tailored N-Heterocyclic Carbene Catalyst

    PubMed Central

    Jang, Ki Po; Hutson, Gerri E.; Johnston, Ryne C.; McCusker, Elizabeth O.; Cheong, Paul H.-Y.; Scheidt, Karl A.

    2014-01-01

    A highly selective NHC-catalyzed synthesis of γ-butyrolactones from the fusion of enals and α-ketophosphonates has been developed. Computational modeling of competing transition states was employed to guide a rational design strategy and achieve enhanced levels of enantioselectivity with a new tailored C1-symmetric biaryl saturated imidazolium-derived NHC catalyst. This new annulation is compatible with a wide range of acyl phosphonates and α,β-unsaturated aldehydes. PMID:24299299

  16. Recent Additions in the Modeling Capabilities of an Open-Source Wave Energy Converter Design Tool: Preprint

    SciTech Connect

    Tom, N.; Lawson, M.; Yu, Y. H.

    2015-04-20

    WEC-Sim is a midfidelity numerical tool for modeling wave energy conversion devices. The code uses the MATLAB SimMechanics package to solve multibody dynamics and models wave interactions using hydrodynamic coefficients derived from frequency-domain boundary-element methods. This paper presents the new modeling features introduced in the latest release of WEC-Sim. The first feature discussed conversion of the fluid memory kernel to a state-space form. This enhancement offers a substantial computational benefit after the hydrodynamic body-to-body coefficients are introduced and the number of interactions increases exponentially with each additional body. Additional features include the ability to calculate the wave-excitation forces based on the instantaneous incident wave angle, allowing the device to weathervane, as well as import a user-defined wave elevation time series. A review of the hydrodynamic theory for each feature is provided and the successful implementation is verified using test cases.

  17. Evidence-Based Communication Practices for Children with Visual Impairments and Additional Disabilities: An Examination of Single-Subject Design Studies

    ERIC Educational Resources Information Center

    Parker, Amy T.; Grimmett, Eric S.; Summers, Sharon

    2008-01-01

    This review examines practices for building effective communication strategies for children with visual impairments, including those with additional disabilities, that have been tested by single-subject design methodology. The authors found 30 studies that met the search criteria and grouped intervention strategies to align any evidence of the…

  18. Viscosity modification of high-oleic sunflower oil with polymeric additives for the design of new biolubricant formulations.

    PubMed

    Quinchia, L A; Delgado, M A; Valencia, C; Franco, J M; Gallegos, C

    2009-03-15

    Although most common lubricants contain mineral or synthetic oils as basestocks, new environmental regulations are demanding environmentally friendly lubricants. In this sense, vegetable oils represent promising alternatives to mineral-based lubricants because of their high biodegradability, good lubricity, and low volatility. However, their poor thermooxidative stability and the small range of viscosity represent a clear disadvantage to be used as suitable biolubricants. The main objective of this work was to develop new environmentally friendly lubricant formulations with improved kinematic viscosity values and viscosity thermal susceptibility. With this aim, a high-oleic sunflower oil (HOSO) was blended with polymeric additives, such as ethylene vinyl acetate (EVA) and styrene-butadiene-styrene (SBS) copolymers, at different concentrations (0.5-5% w/w). Dynamic viscosity and density measurements were performed in a rotational rheometer and capillary densimeter, respectively, in a temperature range between 25 and 120 degrees C. An Arrhenius-like equation fits the evolution of viscosity with temperature fairly well. Both EVA and SBS copolymers may be satisfactorily used as additives to increase the viscosity of HOSO, thus improving the low viscosity values of this oil. HOSO viscosity increases with polymer concentration. Specifically, EVA/HOSO blends exhibit higher viscosity values, which are needed for applications such as lubrication of bearings and four-stroke engines. On the other hand, viscositythermal susceptibility of HOSO samples increases with EVA or SBS concentration.

  19. Designating Additions to the Current List of Tropical Diseases in the Federal Food, Drug, and Cosmetic Act. Final order.

    PubMed

    2015-08-20

    The Federal Food, Drug, and Cosmetic Act (the FD&C Act) authorizes the Food and Drug Administration (FDA or Agency) to award priority review vouchers (PRVs) to tropical disease product applicants when the applications meet certain criteria. The FD&C Act lists the diseases that are considered to be tropical diseases for purposes of obtaining PRVs, and also provides for Agency expansion of that list to include other diseases that satisfy the definition of ``tropical diseases'' as set forth in the FD&C Act. FDA has determined that Chagas disease and neurocysticercosis satisfy this definition, and therefore is adding them to the list of designated tropical diseases whose product applications may result in the award of PRVs. Sponsors submitting certain applications for the treatment of Chagas disease and neurocysticercosis may be eligible to receive a PRV if such applications are approved by FDA.

  20. Designating Additions to the Current List of Tropical Diseases in the Federal Food, Drug, and Cosmetic Act. Final order.

    PubMed

    2015-08-20

    The Federal Food, Drug, and Cosmetic Act (the FD&C Act) authorizes the Food and Drug Administration (FDA or Agency) to award priority review vouchers (PRVs) to tropical disease product applicants when the applications meet certain criteria. The FD&C Act lists the diseases that are considered to be tropical diseases for purposes of obtaining PRVs, and also provides for Agency expansion of that list to include other diseases that satisfy the definition of ``tropical diseases'' as set forth in the FD&C Act. FDA has determined that Chagas disease and neurocysticercosis satisfy this definition, and therefore is adding them to the list of designated tropical diseases whose product applications may result in the award of PRVs. Sponsors submitting certain applications for the treatment of Chagas disease and neurocysticercosis may be eligible to receive a PRV if such applications are approved by FDA. PMID:26292373

  1. Design and Application of Wuhan Ionospheric Oblique Backscattering Sounding System with the Addition of an Antenna Array (WIOBSS-AA).

    PubMed

    Cui, Xiao; Chen, Gang; Wang, Jin; Song, Huan; Gong, Wanlin

    2016-01-01

    The Wuhan Ionospheric Oblique Backscattering Sounding System with the addition of an antenna array (WIOBSS-AA) is the newest member of the WIOBSS family. It is a multi-channel radio system using phased-array antenna technology. The transmitting part of this radio system applies an array composed of five log-periodic antennas to form five beams that span an area to the northwest of the radar site. The hardware and the antenna array of the first multi-channel ionosonde in the WIOBSS family are introduced in detail in this paper. An ionospheric detection experiment was carried out in Chongyang, Hubei province, China on 16 March 2015 to examine the performance of WIOBSS-AA. The radio system demonstrated its ability to obtain ionospheric electron density information over a wide area. The observations indicate that during the experiment, the monitored large-area ionospheric F2-layer was calm and electron density increased with decreasing latitude. PMID:27314360

  2. Design of Selective Gas Sensors Using Additive-Loaded In2O3 Hollow Spheres Prepared by Combinatorial Hydrothermal Reactions

    PubMed Central

    Kim, Sun-Jung; Hwang, In-Sung; Kang, Yun Chan; Lee, Jong-Heun

    2011-01-01

    A combinatorial hydrothermal reaction has been used to prepare pure and additive (Sb, Cu, Nb, Pd, and Ni)-loaded In2O3 hollow spheres for gas sensor applications. The operation of Pd- and Cu-loaded In2O3 sensors at 371 °C leads to selective H2S detection. Selective detection of CO and NH3 was achieved by the Ni-In2O3 sensor at sensing temperatures of 371 and 440 °C, respectively. The gas responses of six different sensors to NH3, H2S, H2, CO and CH4 produced unique gas sensing patterns that can be used for the artificial recognition of these gases. PMID:22346661

  3. Design and Application of Wuhan Ionospheric Oblique Backscattering Sounding System with the Addition of an Antenna Array (WIOBSS-AA)

    PubMed Central

    Cui, Xiao; Chen, Gang; Wang, Jin; Song, Huan; Gong, Wanlin

    2016-01-01

    The Wuhan Ionospheric Oblique Backscattering Sounding System with the addition of an antenna array (WIOBSS-AA) is the newest member of the WIOBSS family. It is a multi-channel radio system using phased-array antenna technology. The transmitting part of this radio system applies an array composed of five log-periodic antennas to form five beams that span an area to the northwest of the radar site. The hardware and the antenna array of the first multi-channel ionosonde in the WIOBSS family are introduced in detail in this paper. An ionospheric detection experiment was carried out in Chongyang, Hubei province, China on 16 March 2015 to examine the performance of WIOBSS-AA. The radio system demonstrated its ability to obtain ionospheric electron density information over a wide area. The observations indicate that during the experiment, the monitored large-area ionospheric F2-layer was calm and electron density increased with decreasing latitude. PMID:27314360

  4. Determination of organic additives in mortars by near-IR spectroscopy. A novel approach to designing a sample set with high-variability components.

    PubMed

    Blanco, Marcelo; Peguero, Anna

    2007-02-01

    Industrial mortars consist primarily of a mixture of cement and an aggregate plus a small amount of additives that are used to modify specific properties. Using too high or too low additive rates usually results in the loss of desirable properties in the end product. This entails carefully controlling the amounts of additives added to mortar in order to ensure correct dosing and/or adequate homogeneity in the final mixture. Near-IR (NIR) spectroscopy has proved effective for this purpose as it requires no sample pretreatment and affords expeditious analyses. The purpose of this work was to determine two organic additives (viz. Ad1 and Ad2) in mortars by using partial least squares regression multivariate calibration models constructed from NIR spectroscopic data. The additives are used to expedite setting and increase cohesion between particles in the mortar. In order to ensure that the sample set contained natural variability in the samples, we used a methodology based on experimental design to construct a representative set of samples. This novel design is based on a hexagonal antiprism that encompasses the concentration ranges spanned by the analytes and the variability inherent in each additive. The D-optimality criterion was used to obtain various combinations between Ad1 and Ad2 additive classes. The partial least squares calibration models thus constructed for each additive provided accurate predictions: the intercept and the slope of the plots of predicted values versus reference values for each additive were close to 0 and 1, respectively, and their confidence ranges included the respective value. The ensuing analytical methods were validated by using an external sample set.

  5. TRACON Aircraft Arrival Planning and Optimization Through Spatial Constraint Satisfaction

    NASA Technical Reports Server (NTRS)

    Bergh, Christopher P.; Krzeczowski, Kenneth J.; Davis, Thomas J.; Denery, Dallas G. (Technical Monitor)

    1995-01-01

    A new aircraft arrival planning and optimization algorithm has been incorporated into the Final Approach Spacing Tool (FAST) in the Center-TRACON Automation System (CTAS) developed at NASA-Ames Research Center. FAST simulations have been conducted over three years involving full-proficiency, level five air traffic controllers from around the United States. From these simulations an algorithm, called Spatial Constraint Satisfaction, has been designed, coded, undergone testing, and soon will begin field evaluation at the Dallas-Fort Worth and Denver International airport facilities. The purpose of this new design is an attempt to show that the generation of efficient and conflict free aircraft arrival plans at the runway does not guarantee an operationally acceptable arrival plan upstream from the runway -information encompassing the entire arrival airspace must be used in order to create an acceptable aircraft arrival plan. This new design includes functions available previously but additionally includes necessary representations of controller preferences and workload, operationally required amounts of extra separation, and integrates aircraft conflict resolution. As a result, the Spatial Constraint Satisfaction algorithm produces an optimized aircraft arrival plan that is more acceptable in terms of arrival procedures and air traffic controller workload. This paper discusses the current Air Traffic Control arrival planning procedures, previous work in this field, the design of the Spatial Constraint Satisfaction algorithm, and the results of recent evaluations of the algorithm.

  6. Demonstration of the Recent Additions in Modeling Capabilities for the WEC-Sim Wave Energy Converter Design Tool: Preprint

    SciTech Connect

    Tom, N.; Lawson, M.; Yu, Y. H.

    2015-03-01

    WEC-Sim is a mid-fidelity numerical tool for modeling wave energy conversion (WEC) devices. The code uses the MATLAB SimMechanics package to solve the multi-body dynamics and models the wave interactions using hydrodynamic coefficients derived from frequency domain boundary element methods. In this paper, the new modeling features introduced in the latest release of WEC-Sim will be presented. The first feature discussed is the conversion of the fluid memory kernel to a state-space approximation that provides significant gains in computational speed. The benefit of the state-space calculation becomes even greater after the hydrodynamic body-to-body coefficients are introduced as the number of interactions increases exponentially with the number of floating bodies. The final feature discussed is the capability toadd Morison elements to provide additional hydrodynamic damping and inertia. This is generally used as a tuning feature, because performance is highly dependent on the chosen coefficients. In this paper, a review of the hydrodynamic theory for each of the features is provided and successful implementation is verified using test cases.

  7. Tandem Solar Cells Using GaAs Nanowires on Si: Design, Fabrication, and Observation of Voltage Addition.

    PubMed

    Yao, Maoqing; Cong, Sen; Arab, Shermin; Huang, Ningfeng; Povinelli, Michelle L; Cronin, Stephen B; Dapkus, P Daniel; Zhou, Chongwu

    2015-11-11

    Multijunction solar cells provide us a viable approach to achieve efficiencies higher than the Shockley-Queisser limit. Due to their unique optical, electrical, and crystallographic features, semiconductor nanowires are good candidates to achieve monolithic integration of solar cell materials that are not lattice-matched. Here, we report the first realization of nanowire-on-Si tandem cells with the observation of voltage addition of the GaAs nanowire top cell and the Si bottom cell with an open circuit voltage of 0.956 V and an efficiency of 11.4%. Our simulation showed that the current-matching condition plays an important role in the overall efficiency. Furthermore, we characterized GaAs nanowire arrays grown on lattice-mismatched Si substrates and estimated the carrier density using photoluminescence. A low-resistance connecting junction was obtained using n(+)-GaAs/p(+)-Si heterojunction. Finally, we demonstrated tandem solar cells based on top GaAs nanowire array solar cells grown on bottom planar Si solar cells. The reported nanowire-on-Si tandem cell opens up great opportunities for high-efficiency, low-cost multijunction solar cells.

  8. Optimum vibrating beams with stress and deflection constraints

    NASA Technical Reports Server (NTRS)

    Kamat, M. P.

    1976-01-01

    The fundamental frequency of vibration of an Euler-Bernoulli or a Timoshenko beam of a specified constant volume is maximized subject to the constraint that under a prescribed loading the maximum stress or maximum deflection at any point along the beam axis will not exceed a specified value. In contrast with the inequality constraint which controls the minimum cross-section, the present inequality constraints lead to more meaningful designs. The inequality constraint on stresses is as easily implemented as the minimum cross-section constraint but the inequality constraint on deflection uses a treatment which is an extension of the matrix partitioning technique of prescribing displacements in finite element analysis.

  9. β-Amino acid catalyzed asymmetric Michael additions: design of organocatalysts with catalytic acid/base dyad inspired by serine proteases.

    PubMed

    Yang, Hui; Wong, Ming Wah

    2011-09-16

    A new type of chiral β-amino acid catalyst has been computationally designed, mimicking the enzyme catalysis of serine proteases. Our catalyst approach is based on the bioinspired catalytic acid/base dyad, namely, a carboxyl and imidazole pair. DFT calculations predict that this designed organocatalyst catalyzes Michael additions of aldehydes to nitroalkenes with excellent enantioselectivities and remarkably high anti diastereoselectivities. The unusual stacked geometry of the enamine intermediate, hydrogen bonding network, and the adoption of an exo transition state are the keys to understand the stereoselectivity.

  10. The Development of Mathematical Prediction Model to Predict Resilient Modulus for Natural Soil Stabilized by Pofa-Opc Additive for the Use in Unpaved Road Design

    NASA Astrophysics Data System (ADS)

    Gamil, Y. M. R.; Bakar, I. H.

    2016-07-01

    Resilient Modulus (Mr) is considered one of the most important parameters in the design of road structure. This paper describes the development of the mathematical model to predict resilient modulus of organic soil stabilized by the mix of Palm Oil Fuel Ash - Ordinary Portland Cement (POFA-OPC) soil stabilization additives. It aims to optimize the use of the use of POFA in soil stabilization. The optimization models enable to eliminate the arbitrary selection and its associated disadvantages in determination of the optimum additive proportion. The model was developed based on Scheffe regression theory. The mix proportions of the samples in the experiment were adopted from similar studies reported in the literature Twenty five samples were designed, prepared and then characterized for each mix proportion based on the MR in 28 days curing. The results are used to develop the mathematical prediction model. The model was statistically analyzed and verified for its adequacy and validity using F-test.

  11. Temporal Constraint Reasoning With Preferences

    NASA Technical Reports Server (NTRS)

    Khatib, Lina; Morris, Paul; Morris, Robert; Rossi, Francesca

    2001-01-01

    A number of reasoning problems involving the manipulation of temporal information can naturally be viewed as implicitly inducing an ordering of potential local decisions involving time (specifically, associated with durations or orderings of events) on the basis of preferences. For example. a pair of events might be constrained to occur in a certain order, and, in addition. it might be preferable that the delay between them be as large, or as small, as possible. This paper explores problems in which a set of temporal constraints is specified, where each constraint is associated with preference criteria for making local decisions about the events involved in the constraint, and a reasoner must infer a complete solution to the problem such that, to the extent possible, these local preferences are met in the best way. A constraint framework for reasoning about time is generalized to allow for preferences over event distances and durations, and we study the complexity of solving problems in the resulting formalism. It is shown that while in general such problems are NP-hard, some restrictions on the shape of the preference functions, and on the structure of the preference set, can be enforced to achieve tractability. In these cases, a simple generalization of a single-source shortest path algorithm can be used to compute a globally preferred solution in polynomial time.

  12. Creating Positive Task Constraints

    ERIC Educational Resources Information Center

    Mally, Kristi K.

    2006-01-01

    Constraints are characteristics of the individual, the task, or the environment that mold and shape movement choices and performances. Constraints can be positive--encouraging proficient movements or negative--discouraging movement or promoting ineffective movements. Physical educators must analyze, evaluate, and determine the effect various…

  13. Constraint Reasoning Over Strings

    NASA Technical Reports Server (NTRS)

    Koga, Dennis (Technical Monitor); Golden, Keith; Pang, Wanlin

    2003-01-01

    This paper discusses an approach to representing and reasoning about constraints over strings. We discuss how many string domains can often be concisely represented using regular languages, and how constraints over strings, and domain operations on sets of strings, can be carried out using this representation.

  14. Credit Constraints in Education

    ERIC Educational Resources Information Center

    Lochner, Lance; Monge-Naranjo, Alexander

    2012-01-01

    We review studies of the impact of credit constraints on the accumulation of human capital. Evidence suggests that credit constraints have recently become important for schooling and other aspects of households' behavior. We highlight the importance of early childhood investments, as their response largely determines the impact of credit…

  15. Using the American alligator and a repeated-measures design to place constraints on in vivo shoulder joint range of motion in dinosaurs and other fossil archosaurs.

    PubMed

    Hutson, Joel D; Hutson, Kelda N

    2013-01-15

    Using the extant phylogenetic bracket of dinosaurs (crocodylians and birds), recent work has reported that elbow joint range of motion (ROM) studies of fossil dinosaur forearms may be providing conservative underestimates of fully fleshed in vivo ROM. As humeral ROM occupies a more central role in forelimb movements, the placement of quantitative constraints on shoulder joint ROM could improve fossil reconstructions. Here, we investigated whether soft tissues affect the more mobile shoulder joint in the same manner in which they affect elbow joint ROM in an extant archosaur. This test involved separately and repeatedly measuring humeral ROM in Alligator mississippiensis as soft tissues were dissected away in stages to bare bone. Our data show that the ROMs of humeral flexion and extension, as well as abduction and adduction, both show a statistically significant increase as flesh is removed, but then decrease when the bones must be physically articulated and moved until they separate from one another and/or visible joint surfaces. A similar ROM pattern is inferred for humeral pronation and supination. All final skeletonized ROMs were less than initial fully fleshed ROMs. These results are consistent with previously reported elbow joint ROM patterns from the extant phylogenetic bracket of dinosaurs. Thus, studies that avoid separation of complementary articular surfaces may be providing fossil shoulder joint ROMs that underestimate in vivo ROM in dinosaurs, as well as other fossil archosaurs.

  16. Reliability Assessment of a Robust Design Under Uncertainty for a 3-D Flexible Wing

    NASA Technical Reports Server (NTRS)

    Gumbert, Clyde R.; Hou, Gene J. -W.; Newman, Perry A.

    2003-01-01

    The paper presents reliability assessment results for the robust designs under uncertainty of a 3-D flexible wing previously reported by the authors. Reliability assessments (additional optimization problems) of the active constraints at the various probabilistic robust design points are obtained and compared with the constraint values or target constraint probabilities specified in the robust design. In addition, reliability-based sensitivity derivatives with respect to design variable mean values are also obtained and shown to agree with finite difference values. These derivatives allow one to perform reliability based design without having to obtain second-order sensitivity derivatives. However, an inner-loop optimization problem must be solved for each active constraint to find the most probable point on that constraint failure surface.

  17. Fast, cheap and out of control--Insights into thermodynamic and informatic constraints on natural protein sequences from de novo protein design.

    PubMed

    Brisendine, Joseph M; Koder, Ronald L

    2016-05-01

    The accumulated results of thirty years of rational and computational de novo protein design have taught us important lessons about the stability, information content, and evolution of natural proteins. First, de novo protein design has complicated the assertion that biological function is equivalent to biological structure - demonstrating the capacity to abstract active sites from natural contexts and paste them into non-native topologies without loss of function. The structure-function relationship has thus been revealed to be either a generality or strictly true only in a local sense. Second, the simplification to "maquette" topologies carried out by rational protein design also has demonstrated that even sophisticated functions such as conformational switching, cooperative ligand binding, and light-activated electron transfer can be achieved with low-information design approaches. This is because for simple topologies the functional footprint in sequence space is enormous and easily exceeds the number of structures which could have possibly existed in the history of life on Earth. Finally, the pervasiveness of extraordinary stability in designed proteins challenges accepted models for the "marginal stability" of natural proteins, suggesting that there must be a selection pressure against highly stable proteins. This can be explained using recent theories which relate non-equilibrium thermodynamics and self-replication. This article is part of a Special Issue entitled Biodesign for Bioenergetics--The design and engineering of electronc transfer cofactors, proteins and protein networks, edited by Ronald L. Koder and J.L. Ross Anderson.

  18. Fast, cheap and out of control--Insights into thermodynamic and informatic constraints on natural protein sequences from de novo protein design.

    PubMed

    Brisendine, Joseph M; Koder, Ronald L

    2016-05-01

    The accumulated results of thirty years of rational and computational de novo protein design have taught us important lessons about the stability, information content, and evolution of natural proteins. First, de novo protein design has complicated the assertion that biological function is equivalent to biological structure - demonstrating the capacity to abstract active sites from natural contexts and paste them into non-native topologies without loss of function. The structure-function relationship has thus been revealed to be either a generality or strictly true only in a local sense. Second, the simplification to "maquette" topologies carried out by rational protein design also has demonstrated that even sophisticated functions such as conformational switching, cooperative ligand binding, and light-activated electron transfer can be achieved with low-information design approaches. This is because for simple topologies the functional footprint in sequence space is enormous and easily exceeds the number of structures which could have possibly existed in the history of life on Earth. Finally, the pervasiveness of extraordinary stability in designed proteins challenges accepted models for the "marginal stability" of natural proteins, suggesting that there must be a selection pressure against highly stable proteins. This can be explained using recent theories which relate non-equilibrium thermodynamics and self-replication. This article is part of a Special Issue entitled Biodesign for Bioenergetics--The design and engineering of electronc transfer cofactors, proteins and protein networks, edited by Ronald L. Koder and J.L. Ross Anderson. PMID:26498191

  19. Food additives

    PubMed Central

    Spencer, Michael

    1974-01-01

    Food additives are discussed from the food technology point of view. The reasons for their use are summarized: (1) to protect food from chemical and microbiological attack; (2) to even out seasonal supplies; (3) to improve their eating quality; (4) to improve their nutritional value. The various types of food additives are considered, e.g. colours, flavours, emulsifiers, bread and flour additives, preservatives, and nutritional additives. The paper concludes with consideration of those circumstances in which the use of additives is (a) justified and (b) unjustified. PMID:4467857

  20. Relationship between participation in leisure activities and constraints on Taiwanese breastfeeding mothers during leisure activities

    PubMed Central

    2013-01-01

    Background Participation in leisure activities strongly associates with health and well-being. Little research has explored the relationship between participation in leisure activities and constraints on breastfeeding mothers during leisure activities. The purposes of this study are: 1) to investigate constraints on breastfeeding mothers during leisure activities and participation in leisure activities; 2) to investigate the differences between preferences for leisure activities and actual participation by breastfeeding mothers; 3) to segment breastfeeding mothers with similar patterns, using a cluster analysis based on the delineated participation in leisure activities and leisure preferences; 4) to explore any differences between clusters of breastfeeding mothers with respect to socio-demographic characteristics, breastfeeding behaviours and leisure constraints. Methods This study has a cross-sectional design using an online survey conducted among mothers having breastfeeding experiences of more than four months. The questionnaire includes demographic variables, breastfeeding behaviours, preferences for leisure activities participation, and constraints on leisure activities. Collection of data occurred between March and July 2011, producing 415 valid responses for analysis. Results For breastfeeding mothers, this study identifies constraints on breastfeeding related to leisure activities in addition to the three traditional factors for constraints in the model. This study demonstrates that reports of constraints related to children, family, and nursing environments are the most frequent. Breastfeeding mothers in Taiwan participate regularly in family activities or activities related to their children. Cluster analysis classified breastfeeding mothers into Action and Contemplation groups, and found that mothers within the latter group participate less in leisure activities and experienced more constraints related to breastfeeding. Conclusions Implications provide

  1. Robust tracking control for an air-breathing hypersonic vehicle with input constraints

    NASA Astrophysics Data System (ADS)

    Gao, Gang; Wang, Jinzhi; Wang, Xianghua

    2014-12-01

    The focus of this paper is on the design and simulation of robust tracking control for an air-breathing hypersonic vehicle (AHV), which is affected by high nonlinearity, uncertain parameters and input constraints. The linearisation method is employed for the longitudinal AHV model about a specific trim condition, and then considering the additive uncertainties of three parameters, the linearised model is just in the form of affine parameter dependence. From this point, the linear parameter-varying method is applied to design the desired controller. The poles for the closed-loop system of the linearised model are placed into a desired vertical strip, and the quadratic stability of the closed-loop system is guaranteed. Input constraints of the AHV are addressed by additional linear matrix inequalities. Finally, the designed controller is evaluated on the nonlinear AHV model and simulation results demonstrate excellent tracking performance with good robustness.

  2. Constraint Based Modeling Going Multicellular

    PubMed Central

    Martins Conde, Patricia do Rosario; Sauter, Thomas; Pfau, Thomas

    2016-01-01

    Constraint based modeling has seen applications in many microorganisms. For example, there are now established methods to determine potential genetic modifications and external interventions to increase the efficiency of microbial strains in chemical production pipelines. In addition, multiple models of multicellular organisms have been created including plants and humans. While initially the focus here was on modeling individual cell types of the multicellular organism, this focus recently started to switch. Models of microbial communities, as well as multi-tissue models of higher organisms have been constructed. These models thereby can include different parts of a plant, like root, stem, or different tissue types in the same organ. Such models can elucidate details of the interplay between symbiotic organisms, as well as the concerted efforts of multiple tissues and can be applied to analyse the effects of drugs or mutations on a more systemic level. In this review we give an overview of the recent development of multi-tissue models using constraint based techniques and the methods employed when investigating these models. We further highlight advances in combining constraint based models with dynamic and regulatory information and give an overview of these types of hybrid or multi-level approaches. PMID:26904548

  3. Constraint Based Modeling Going Multicellular.

    PubMed

    Martins Conde, Patricia do Rosario; Sauter, Thomas; Pfau, Thomas

    2016-01-01

    Constraint based modeling has seen applications in many microorganisms. For example, there are now established methods to determine potential genetic modifications and external interventions to increase the efficiency of microbial strains in chemical production pipelines. In addition, multiple models of multicellular organisms have been created including plants and humans. While initially the focus here was on modeling individual cell types of the multicellular organism, this focus recently started to switch. Models of microbial communities, as well as multi-tissue models of higher organisms have been constructed. These models thereby can include different parts of a plant, like root, stem, or different tissue types in the same organ. Such models can elucidate details of the interplay between symbiotic organisms, as well as the concerted efforts of multiple tissues and can be applied to analyse the effects of drugs or mutations on a more systemic level. In this review we give an overview of the recent development of multi-tissue models using constraint based techniques and the methods employed when investigating these models. We further highlight advances in combining constraint based models with dynamic and regulatory information and give an overview of these types of hybrid or multi-level approaches.

  4. Constraint Based Modeling Going Multicellular.

    PubMed

    Martins Conde, Patricia do Rosario; Sauter, Thomas; Pfau, Thomas

    2016-01-01

    Constraint based modeling has seen applications in many microorganisms. For example, there are now established methods to determine potential genetic modifications and external interventions to increase the efficiency of microbial strains in chemical production pipelines. In addition, multiple models of multicellular organisms have been created including plants and humans. While initially the focus here was on modeling individual cell types of the multicellular organism, this focus recently started to switch. Models of microbial communities, as well as multi-tissue models of higher organisms have been constructed. These models thereby can include different parts of a plant, like root, stem, or different tissue types in the same organ. Such models can elucidate details of the interplay between symbiotic organisms, as well as the concerted efforts of multiple tissues and can be applied to analyse the effects of drugs or mutations on a more systemic level. In this review we give an overview of the recent development of multi-tissue models using constraint based techniques and the methods employed when investigating these models. We further highlight advances in combining constraint based models with dynamic and regulatory information and give an overview of these types of hybrid or multi-level approaches. PMID:26904548

  5. Fuel characteristics pertinent to the design of aircraft fuel systems, Supplement I : additional information on MIL-F-7914(AER) grade JP-5 fuel and several fuel oils

    NASA Technical Reports Server (NTRS)

    Barnett, Henry C; Hibbard, Robert R

    1953-01-01

    Since the release of the first NACA publication on fuel characteristics pertinent to the design of aircraft fuel systems (NACA-RM-E53A21), additional information has become available on MIL-F7914(AER) grade JP-5 fuel and several of the current grades of fuel oils. In order to make this information available to fuel-system designers as quickly as possible, the present report has been prepared as a supplement to NACA-RM-E53A21. Although JP-5 fuel is of greater interest in current fuel-system problems than the fuel oils, the available data are not as extensive. It is believed, however, that the limited data on JP-5 are sufficient to indicate the variations in stocks that the designer must consider under a given fuel specification. The methods used in the preparation and extrapolation of data presented in the tables and figures of this supplement are the same as those used in NACA-RM-E53A21.

  6. Some design constraints required for the use of generic software in embedded systems: Packages which manage abstract dynamic structures without the need for garbage collection

    NASA Technical Reports Server (NTRS)

    Johnson, Charles S.

    1986-01-01

    The embedded systems running real-time applications, for which Ada was designed, require their own mechanisms for the management of dynamically allocated storage. There is a need for packages which manage their own internalo structures to control their deallocation as well, due to the performance implications of garbage collection by the KAPSE. This places a requirement upon the design of generic packages which manage generically structured private types built-up from application-defined input types. These kinds of generic packages should figure greatly in the development of lower-level software such as operating systems, schedulers, controllers, and device driver; and will manage structures such as queues, stacks, link-lists, files, and binary multary (hierarchical) trees. Controlled to prevent inadvertent de-designation of dynamic elements, which is implicit in the assignment operation A study was made of the use of limited private type, in solving the problems of controlling the accumulation of anonymous, detached objects in running systems. The use of deallocator prodecures for run-down of application-defined input types during deallocation operations during satellites.

  7. Constraint-based Attribute and Interval Planning

    NASA Technical Reports Server (NTRS)

    Jonsson, Ari; Frank, Jeremy

    2013-01-01

    In this paper we describe Constraint-based Attribute and Interval Planning (CAIP), a paradigm for representing and reasoning about plans. The paradigm enables the description of planning domains with time, resources, concurrent activities, mutual exclusions among sets of activities, disjunctive preconditions and conditional effects. We provide a theoretical foundation for the paradigm, based on temporal intervals and attributes. We then show how the plans are naturally expressed by networks of constraints, and show that the process of planning maps directly to dynamic constraint reasoning. In addition, we de ne compatibilities, a compact mechanism for describing planning domains. We describe how this framework can incorporate the use of constraint reasoning technology to improve planning. Finally, we describe EUROPA, an implementation of the CAIP framework.

  8. A novel implementation of method of optimality criterion in synthesizing spacecraft structures with natural frequency constraints

    NASA Technical Reports Server (NTRS)

    Wang, Bo Ping; Chu, F. H.

    1989-01-01

    In the design of spacecraft structures, fine tuning the structure to achieve minimum weight with natural frequency constraints is a time consuming process. Here, a novel implementation of the method of optimality criterion (OC) is developed. In this new implementation of OC, the free vibration analysis results are used to compute the eigenvalue sensitivity data required for the formulation. Specifically, the modal elemental strain and kinetic energies are used. Additionally, normalized design parameters are introduced as a second level linking that allows design variables of different values to be linked together. With the use of this novel formulation, synthesis of structures with natural frequency constraint can be carried out manually using modal analysis results. Design examples are presented to illustrate this novel implementation of the optimality criterion method.

  9. Constraints in Genetic Programming

    NASA Technical Reports Server (NTRS)

    Janikow, Cezary Z.

    1996-01-01

    Genetic programming refers to a class of genetic algorithms utilizing generic representation in the form of program trees. For a particular application, one needs to provide the set of functions, whose compositions determine the space of program structures being evolved, and the set of terminals, which determine the space of specific instances of those programs. The algorithm searches the space for the best program for a given problem, applying evolutionary mechanisms borrowed from nature. Genetic algorithms have shown great capabilities in approximately solving optimization problems which could not be approximated or solved with other methods. Genetic programming extends their capabilities to deal with a broader variety of problems. However, it also extends the size of the search space, which often becomes too large to be effectively searched even by evolutionary methods. Therefore, our objective is to utilize problem constraints, if such can be identified, to restrict this space. In this publication, we propose a generic constraint specification language, powerful enough for a broad class of problem constraints. This language has two elements -- one reduces only the number of program instances, the other reduces both the space of program structures as well as their instances. With this language, we define the minimal set of complete constraints, and a set of operators guaranteeing offspring validity from valid parents. We also show that these operators are not less efficient than the standard genetic programming operators if one preprocesses the constraints - the necessary mechanisms are identified.

  10. The "Myth" of the Minimum SAR Antenna Area Constraint

    NASA Technical Reports Server (NTRS)

    Freeman, A.; Johnson, W. T. K.; Huneycutt, B.; Jordan, R.; Hensley, S.; Siqueira, P.; Curlander, J.

    1998-01-01

    A design constraint traceable ot the early days of spaceborne Synthetic Aperture Radar (SAR) is known as the minimum antenna area constraint for SAR. In this paper, it is confirmed that this constraint strictly applies only to the case where both the best possible resolution and the widest possible swath are the design goals. SAR antennas with area smaller than the constraint allows are shown to be possible, have been used on spaceborne SAR missions in the past, and should permit further, lower-cost SAR mission in the future.

  11. NMR Constraints Analyser: a web-server for the graphical analysis of NMR experimental constraints.

    PubMed

    Heller, Davide Martin; Giorgetti, Alejandro

    2010-07-01

    Nuclear magnetic resonance (NMR) spectroscopy together with X-ray crystallography, are the main techniques used for the determination of high-resolution 3D structures of biological molecules. The output of an NMR experiment includes a set of lower and upper limits for the distances (constraints) between pairs of atoms. If the number of constraints is high enough, there will be a finite number of possible conformations (models) of the macromolecule satisfying the data. Thus, the more constraints are measured, the better defined these structures will be. The availability of a user-friendly tool able to help in the analysis and interpretation of the number of experimental constraints per residue, is thus of valuable importance when assessing the levels of structure definition of NMR solved biological macromolecules, in particular, when high-quality structures are needed in techniques such as, computational biology approaches, site-directed mutagenesis experiments and/or drug design. Here, we present a free publicly available web-server, i.e. NMR Constraints Analyser, which is aimed at providing an automatic graphical analysis of the NMR experimental constraints atom by atom. The NMR Constraints Analyser server is available from the web-page http://molsim.sci.univr.it/constraint.

  12. Design and validation of bicyclic iminopyrimidinones as beta amyloid cleaving enzyme-1 (BACE1) inhibitors: conformational constraint to favor a bioactive conformation.

    PubMed

    Mandal, Mihirbaran; Zhu, Zhaoning; Cumming, Jared N; Liu, Xiaoxiang; Strickland, Corey; Mazzola, Robert D; Caldwell, John P; Leach, Prescott; Grzelak, Michael; Hyde, Lynn; Zhang, Qi; Terracina, Giuseppe; Zhang, Lili; Chen, Xia; Kuvelkar, Reshma; Kennedy, Matthew E; Favreau, Leonard; Cox, Kathleen; Orth, Peter; Buevich, Alexei; Voigt, Johannes; Wang, Hongwu; Kazakevich, Irina; McKittrick, Brian A; Greenlee, William; Parker, Eric M; Stamford, Andrew W

    2012-11-01

    On the basis of our observation that the biaryl substituent of iminopyrimidinone 7 must be in a pseudoaxial conformation to occupy the contiguous S1-S3 subsites of BACE1, we have designed a novel fused bicyclic iminopyrimidinone scaffold intended to favor this bioactive conformation. Strategic incorporation of a nitrogen atom in the new constrained ring allowed us to develop SAR around the S2' binding pocket and ultimately resulted in analogues with low nanomolar potency for BACE1. In particular, optimization of the prime side substituent led to major improvements in potency by displacement of two conserved water molecules from a region near S2'. Further optimization of the pharmacokinetic properties of this fused pyrrolidine series, in conjunction with facile access to a rat pharmacodynamic model, led to identification of compound 43, which is an orally active, brain penetrant inhibitor that reduces Aβ(40) in the plasma, CSF, and cortex of rats in a dose-dependent manner.

  13. Challenges of Designing a 13-Hz High-Load Vibration Isolation System with Tight Volume Constraints: Lessons Learned and Path Forward

    NASA Technical Reports Server (NTRS)

    Dearing, Stella; Ruebsamen, Dale

    2016-01-01

    This paper describes the design of a passive isolation system using D-struts (Registered TradeMark) to isolate an optical payload from aircraft-borne jitter with challenging stroke per volume requirements. It discusses the use of viscoelastic-coated D-struts® that meet the customer performance and outgassing specification, NASA-1124. The result was a relatively soft isolation system, (where the first mode was 13 Hz), with each individual strut capable of withstanding loads on the order of magnitude of 623 N (140 lbf), weighing less than 910 g (2 lbm), fitting in a volume 5.1 cm (2 inches) in diameter and 12-cm (4.7-inches) long and capable of performing up to 1000 Hz without nonlinearities.

  14. Effectiveness: N(sub TU) relationships for the design and performance evaluation of additional shell-and-tube heat exchanger geometries

    NASA Astrophysics Data System (ADS)

    1988-11-01

    This Data Item 88021, an addition to the Sub-series on Heat Transfer, complements ESDU 86018 by extending the range of configurations covered there and in particular considering the effect of using small numbers of baffles for E- and J-shells and the use of J-shells in series. It also explores the limitations of the assumptions associated with the effectiveness - N(sub TU) method and shows where those assumptions break down. The curves presented for each exchanger geometry show the locus of designs for which a temperature cross may occur and the locus of 95 percent heat transfer effectiveness which indicates the region of uneconomic design. The method assumes a linear temperature/enthalpy relationship (constant specific heat capacity) for both streams. It applies to boiling or condensing flow of a single component with no temperature change, or boiling and condensing flow of a mixture that is always two-phase. It excludes conditions in which transition from single- to two-phase flow occurs. However, by use of average property values, it is possible to extend the method to apply to cases where there is some variation of physical and thermodynamic properties with temperature.

  15. General constraints on the Viking biology investigation

    NASA Technical Reports Server (NTRS)

    Klein, H. P.

    1976-01-01

    The paper discusses some of the constraints pertaining to the Viking mission for detection of life on Mars, within which the Viking experiments were conceived, designed, and developed. The most important limitation to the entire study is the complete information about the nature of Mars, such as the chemical composition of the surface material of Mars and the exact identification of the constituents of that planet. Ways in which celestial mechanics places severe limitations on the Viking biology investigation are discussed. Major engineering constraints are examined relative to the accomodation of biology instrument inside the Viking lander and to the design of the instrument itself. Other constraints discussed concern the operational aspects of the mission and the testing program.

  16. Balancing Science Objectives and Operational Constraints: A Mission Planner's Challenge

    NASA Technical Reports Server (NTRS)

    Weldy, Michelle

    1996-01-01

    The Air Force minute sensor technology integration (MSTI-3) satellite's primary mission is to characterize Earth's atmospheric background clutter. MSTI-3 will use three cameras for data collection, a mid-wave infrared imager, a short wave infrared imager, and a visible imaging spectrometer. Mission science objectives call for the collection of over 2 million images within the one year mission life. In addition, operational constraints limit camera usage to four operations of twenty minutes per day, with no more than 10,000 data and calibrating images collected per day. To balance the operational constraints and science objectives, the mission planning team has designed a planning process to e event schedules and sensor operation timelines. Each set of constraints, including spacecraft performance capabilities, the camera filters, the geographical regions, and the spacecraft-Sun-Earth geometries of interest, and remote tracking station deconflictions has been accounted for in this methodology. To aid in this process, the mission planning team is building a series of tools from commercial off-the-shelf software. These include the mission manifest which builds a daily schedule of events, and the MSTI Scene Simulator which helps build geometrically correct scans. These tools provide an efficient, responsive, and highly flexible architecture that maximizes data collection while minimizing mission planning time.

  17. Phosphazene additives

    DOEpatents

    Harrup, Mason K; Rollins, Harry W

    2013-11-26

    An additive comprising a phosphazene compound that has at least two reactive functional groups and at least one capping functional group bonded to phosphorus atoms of the phosphazene compound. One of the at least two reactive functional groups is configured to react with cellulose and the other of the at least two reactive functional groups is configured to react with a resin, such as an amine resin of a polycarboxylic acid resin. The at least one capping functional group is selected from the group consisting of a short chain ether group, an alkoxy group, or an aryloxy group. Also disclosed are an additive-resin admixture, a method of treating a wood product, and a wood product.

  18. Potlining Additives

    SciTech Connect

    Rudolf Keller

    2004-08-10

    In this project, a concept to improve the performance of aluminum production cells by introducing potlining additives was examined and tested. Boron oxide was added to cathode blocks, and titanium was dissolved in the metal pool; this resulted in the formation of titanium diboride and caused the molten aluminum to wet the carbonaceous cathode surface. Such wetting reportedly leads to operational improvements and extended cell life. In addition, boron oxide suppresses cyanide formation. This final report presents and discusses the results of this project. Substantial economic benefits for the practical implementation of the technology are projected, especially for modern cells with graphitized blocks. For example, with an energy savings of about 5% and an increase in pot life from 1500 to 2500 days, a cost savings of $ 0.023 per pound of aluminum produced is projected for a 200 kA pot.

  19. Adaptive laser link reconfiguration using constraint propagation

    NASA Technical Reports Server (NTRS)

    Crone, M. S.; Julich, P. M.; Cook, L. M.

    1993-01-01

    This paper describes Harris AI research performed on the Adaptive Link Reconfiguration (ALR) study for Rome Lab, and focuses on the application of constraint propagation to the problem of link reconfiguration for the proposed space based Strategic Defense System (SDS) Brilliant Pebbles (BP) communications system. According to the concept of operations at the time of the study, laser communications will exist between BP's and to ground entry points. Long-term links typical of RF transmission will not exist. This study addressed an initial implementation of BP's based on the Global Protection Against Limited Strikes (GPALS) SDI mission. The number of satellites and rings studied was representative of this problem. An orbital dynamics program was used to generate line-of-site data for the modeled architecture. This was input into a discrete event simulation implemented in the Harris developed COnstraint Propagation Expert System (COPES) Shell, developed initially on the Rome Lab BM/C3 study. Using a model of the network and several heuristics, the COPES shell was used to develop the Heuristic Adaptive Link Ordering (HALO) Algorithm to rank and order potential laser links according to probability of communication. A reduced set of links based on this ranking would then be used by a routing algorithm to select the next hop. This paper includes an overview of Constraint Propagation as an Artificial Intelligence technique and its embodiment in the COPES shell. It describes the design and implementation of both the simulation of the GPALS BP network and the HALO algorithm in COPES. This is described using a 59 Data Flow Diagram, State Transition Diagrams, and Structured English PDL. It describes a laser communications model and the heuristics involved in rank-ordering the potential communication links. The generation of simulation data is described along with its interface via COPES to the Harris developed View Net graphical tool for visual analysis of communications

  20. Precision Constraints on Extra Fermion Generations

    SciTech Connect

    Erler, Jens; Langacker, Paul

    2010-07-16

    There has been recent renewed interest in the possibility of additional fermion generations. At the same time there have been significant changes in the relevant electroweak precision constraints, in particular, in the interpretation of several of the low energy experiments. We summarize the various motivations for extra families and analyze them in view of the latest electroweak precision data.

  1. Total System Performance Assessment-License Application Design Selection (LADS) Phase 1 Analysis of Surface Modification Consisting of Addition of Alluvium (Feature 23a)

    SciTech Connect

    N. Erb

    1999-06-11

    The objective of this report is to document the analysis that was conducted to evaluate the effect of a potential change to the TSPA-VA base case design that could improve long-term repository performance. The design feature evaluated in this report is a modification of the topographic surface of Yucca Mountain. The modification consists of covering the land surface immediately above the repository foot-print with a thick layer of unconsolidated material utilizing rip-rap and plants to mitigate erosion. This surface modification is designated as Feature 23a or simply abbreviated as F23a. The fundamental aim of F23a is to reduce the net infiltration into the unsaturated zone by enhancing the potential for evapotranspiratiration at the surface; such a change would, in turn, reduce the seepage flux and the rate of radionuclide releases from the repository. Field and modeling studies of water movement in the unsaturated zone have indicated that shallow infiltration at the surface is almost negligible in locations where the bedrock is covered by a sufficiently thick soil layer. In addition to providing storage for meteoric water, a thick soil layer would slow the downward movement of soil moisture to such an extent that evaporation and transpiration could easily transfer most of the soil-water back to the atmosphere. Generic requirements for the effectiveness of this design feature are two-fold. First, the soil layer above the repository foot-print must be thick enough to provide sufficient storage of meteoric water (from episodic precipitation events) and accommodate plant roots. Second, the added soil layer must be engineered so as to mitigate thinning by erosional processes and have sufficient thickness to accommodate the roots of common desert plants. Under these two conditions, it is reasonable to expect that modification would be effective for a significant time period and the net infiltration and deep percolation flux would be reduced by orders of magnitude lower

  2. Design of Phosphonium-Type Zwitterion as an Additive to Improve Saturated Water Content of Phase-Separated Ionic Liquid from Aqueous Phase toward Reversible Extraction of Proteins

    PubMed Central

    Ito, Yoritsugu; Kohno, Yuki; Nakamura, Nobuhumi; Ohno, Hiroyuki

    2013-01-01

    We designed phosphonium-type zwitterion (ZI) to control the saturated water content of separated ionic liquid (IL) phase in the hydrophobic IL/water biphasic systems. The saturated water content of separated IL phase, 1-butyl-3-methyimidazolium bis(trifluoromethanesulfonyl)imide, was considerably improved from 0.4 wt% to 62.8 wt% by adding N,N,N-tripentyl-4-sulfonyl-1-butanephosphonium-type ZI (P555C4S). In addition, the maximum water content decreased from 62.8 wt% to 34.1 wt% by increasing KH2PO4/K2HPO4 salt content in upper aqueous phosphate buffer phase. Horse heart cytochrome c (cyt.c) was dissolved selectively in IL phase by improving the water content of IL phase, and spectroscopic analysis revealed that the dissolved cyt.c retained its higher ordered structure. Furthermore, cyt. c dissolved in IL phase was re-extracted again from IL phase to aqueous phase by increasing the concentration of inorganic salts of the buffer solution. PMID:24013379

  3. Solving the Big Data (BD) Problem in Advanced Manufacturing (Subcategory for work done at Georgia Tech. Study Process and Design Factors for Additive Manufacturing Improvement)

    SciTech Connect

    Clark, Brett W.; Diaz, Kimberly A.; Ochiobi, Chinaza Darlene; Paynabar, Kamran

    2015-09-01

    3D printing originally known as additive manufacturing is a process of making 3 dimensional solid objects from a CAD file. This ground breaking technology is widely used for industrial and biomedical purposes such as building objects, tools, body parts and cosmetics. An important benefit of 3D printing is the cost reduction and manufacturing flexibility; complex parts are built at the fraction of the price. However, layer by layer printing of complex shapes adds error due to the surface roughness. Any such error results in poor quality products with inaccurate dimensions. The main purpose of this research is to measure the amount of printing errors for parts with different geometric shapes and to analyze them for finding optimal printing settings to minimize the error. We use a Design of Experiments framework, and focus on studying parts with cone and ellipsoid shapes. We found that the orientation and the shape of geometric shapes have significant effect on the printing error. From our analysis, we also determined the optimal orientation that gives the least printing error.

  4. Reduction of Constraints: Applicability of the Homogeneity Constraint for Macrobatch 3

    SciTech Connect

    Peeler, D.K.

    2001-02-15

    The Product Composition Control System (PCCS) is used to determine the acceptability of each batch of Defense Waste Processing Facility (DWPF) melter feed in the Slurry Mix Evaporator (SME). This control system imposes several constraints on the composition of the contents of the SME to define acceptability. These constraints relate process or product properties to composition via prediction models. A SME batch is deemed acceptable if its sample composition measurements lead to acceptable property predictions after accounting for modeling, measurement and analytic uncertainties. The baseline document guiding the use of these data and models is ''SME Acceptability Determination for DWPF Process Control (U)'' by Brown and Postles [1996]. A minimum of three PCCS constraints support the prediction of the glass durability from a given SME batch. The Savannah River Technology Center (SRTC) is reviewing all of the PCCS constraints associated with durability. The purpose of this review is to revisit these constraints in light of the additional knowledge gained since the beginning of radioactive operations at DWPF and to identify any supplemental studies needed to amplify this knowledge so that redundant or overly conservative constraints can be eliminated or replaced by more appropriate constraints.

  5. Balancing Flexible Constraints and Measurement Precision in Computerized Adaptive Testing

    ERIC Educational Resources Information Center

    Moyer, Eric L.; Galindo, Jennifer L.; Dodd, Barbara G.

    2012-01-01

    Managing test specifications--both multiple nonstatistical constraints and flexibly defined constraints--has become an important part of designing item selection procedures for computerized adaptive tests (CATs) in achievement testing. This study compared the effectiveness of three procedures: constrained CAT, flexible modified constrained CAT,…

  6. Dynamical Constraints on Exoplanets

    NASA Astrophysics Data System (ADS)

    Horner, Jonti; Wittenmyer, Robert A.; Tinney, Chris; Hinse, Tobias C.; Marshall, Jonathan P.

    2014-01-01

    Dynamical studies of new exoplanet systems are a critical component of the discovery and characterisation process. Such studies can provide firmer constraints on the parameters of the newly discovered planets, and may even reveal that the proposed planets do not stand up to dynamical scrutiny. Here, we demonstrate how dynamical studies can assist the characterisation of such systems through two examples: QS Virginis and HD 73526.

  7. Covariant constraints in ghost free massive gravity

    SciTech Connect

    Deffayet, C.; Mourad, J.; Zahariade, G. E-mail: mourad@apc.univ-paris7.fr

    2013-01-01

    We show that the reformulation of the de Rham-Gabadadze-Tolley massive gravity theory using vielbeins leads to a very simple and covariant way to count constraints, and hence degrees of freedom. Our method singles out a subset of theories, in the de Rham-Gabadadze-Tolley family, where an extra constraint, needed to eliminate the Boulware Deser ghost, is easily seen to appear. As a side result, we also introduce a new method, different from the Stuckelberg trick, to extract kinetic terms for the polarizations propagating in addition to those of the massless graviton.

  8. Constraint-based scheduling

    NASA Technical Reports Server (NTRS)

    Zweben, Monte

    1991-01-01

    The GERRY scheduling system developed by NASA Ames with assistance from the Lockheed Space Operations Company, and the Lockheed Artificial Intelligence Center, uses a method called constraint based iterative repair. Using this technique, one encodes both hard rules and preference criteria into data structures called constraints. GERRY repeatedly attempts to improve schedules by seeking repairs for violated constraints. The system provides a general scheduling framework which is being tested on two NASA applications. The larger of the two is the Space Shuttle Ground Processing problem which entails the scheduling of all inspection, repair, and maintenance tasks required to prepare the orbiter for flight. The other application involves power allocations for the NASA Ames wind tunnels. Here the system will be used to schedule wind tunnel tests with the goal of minimizing power costs. In this paper, we describe the GERRY system and its applications to the Space Shuttle problem. We also speculate as to how the system would be used for manufacturing, transportation, and military problems.

  9. Constraint-based scheduling

    NASA Technical Reports Server (NTRS)

    Zweben, Monte

    1991-01-01

    The GERRY scheduling system developed by NASA Ames with assistance from the Lockheed Space Operations Company, and the Lockheed Artificial Intelligence Center, uses a method called constraint-based iterative repair. Using this technique, one encodes both hard rules and preference criteria into data structures called constraints. GERRY repeatedly attempts to improve schedules by seeking repairs for violated constraints. The system provides a general scheduling framework which is being tested on two NASA applications. The larger of the two is the Space Shuttle Ground Processing problem which entails the scheduling of all the inspection, repair, and maintenance tasks required to prepare the orbiter for flight. The other application involves power allocation for the NASA Ames wind tunnels. Here the system will be used to schedule wind tunnel tests with the goal of minimizing power costs. In this paper, we describe the GERRY system and its application to the Space Shuttle problem. We also speculate as to how the system would be used for manufacturing, transportation, and military problems.

  10. Constraint-based scheduling

    NASA Technical Reports Server (NTRS)

    Zweben, Monte

    1993-01-01

    The GERRY scheduling system developed by NASA Ames with assistance from the Lockheed Space Operations Company, and the Lockheed Artificial Intelligence Center, uses a method called constraint-based iterative repair. Using this technique, one encodes both hard rules and preference criteria into data structures called constraints. GERRY repeatedly attempts to improve schedules by seeking repairs for violated constraints. The system provides a general scheduling framework which is being tested on two NASA applications. The larger of the two is the Space Shuttle Ground Processing problem which entails the scheduling of all the inspection, repair, and maintenance tasks required to prepare the orbiter for flight. The other application involves power allocation for the NASA Ames wind tunnels. Here the system will be used to schedule wind tunnel tests with the goal of minimizing power costs. In this paper, we describe the GERRY system and its application to the Space Shuttle problem. We also speculate as to how the system would be used for manufacturing, transportation, and military problems.

  11. Verification of Pointing Constraints for the Dawn Spacecraft

    NASA Technical Reports Server (NTRS)

    Vanelli, C. Anthony; Swenka, Edward; Smith, Brett

    2008-01-01

    NASA's Dawn spacecraft, an ion-thrust science mission to Vesta and Ceres, has numerous pointing constraints critical for safe operation. Onboard software automatically chooses target attitudes but enforces only a simplified constraint set at slew endpoints. Onboard fault-protection also uses simplified constraints, and violations can result in safing events that dramatically consume mission margins for missed thrust. Lastly, for funding reasons the operations team is lean, forcing the development of month-long command sequences. These factors place a premium on reliable maneuver design, prediction, and verification against pointing constraints. This paper presents Slewth, a ground tool built to address these concerns.

  12. Hard Constraints in Optimization Under Uncertainty

    NASA Technical Reports Server (NTRS)

    Crespo, Luis G.; Giesy, Daniel P.; Kenny, Sean P.

    2008-01-01

    This paper proposes a methodology for the analysis and design of systems subject to parametric uncertainty where design requirements are specified via hard inequality constraints. Hard constraints are those that must be satisfied for all parameter realizations within a given uncertainty model. Uncertainty models given by norm-bounded perturbations from a nominal parameter value, i.e., hyper-spheres, and by sets of independently bounded uncertain variables, i.e., hyper-rectangles, are the focus of this paper. These models, which are also quite practical, allow for a rigorous mathematical treatment within the proposed framework. Hard constraint feasibility is determined by sizing the largest uncertainty set for which the design requirements are satisfied. Analytically verifiable assessments of robustness are attained by comparing this set with the actual uncertainty model. Strategies that enable the comparison of the robustness characteristics of competing design alternatives, the description and approximation of the robust design space, and the systematic search for designs with improved robustness are also proposed. Since the problem formulation is generic and the tools derived only require standard optimization algorithms for their implementation, this methodology is applicable to a broad range of engineering problems.

  13. A Constraint-based Attribute and Interval Planning

    NASA Technical Reports Server (NTRS)

    Frank, Jeremy; Jonsson, Ari; Clancy, Daniel (Technical Monitor)

    2001-01-01

    In this paper we introduce Constraint-based Attribute and Interval Planning (CAIP), a new paradigm for representing and reasoning about plans. The paradigm enables the description of planning domains with time, resources, concurrent activities, mutual exclusions among sets of activities, disjunctive preconditions and conditional effects. We provide a theoretical foundation for the paradigm using a mapping to first order logic. We also show that CAIP plans are naturally expressed by networks of constraints, and that planning maps directly to dynamic constraint reasoning. In addition, we show how constraint templates are used to provide a compact mechanism for describing planning domains.

  14. The enigma of nonholonomic constraints

    NASA Astrophysics Data System (ADS)

    Flannery, M. R.

    2005-03-01

    The problems associated with the modification of Hamilton's principle to cover nonholonomic constraints by the application of the multiplier theorem of variational calculus are discussed. The reason for the problems is subtle and is discussed, together with the reason why the proper account of nonholonomic constraints is outside the scope of Hamilton's variational principle. However, linear velocity constraints remain within the scope of D'Alembert's principle. A careful and comprehensive analysis facilitates the resolution of the puzzling features of nonholonomic constraints.

  15. Structure Constraints in a Constraint-Based Planner

    NASA Technical Reports Server (NTRS)

    Pang, Wan-Lin; Golden, Keith

    2004-01-01

    In this paper we report our work on a new constraint domain, where variables can take structured values. Earth-science data processing (ESDP) is a planning domain that requires the ability to represent and reason about complex constraints over structured data, such as satellite images. This paper reports on a constraint-based planner for ESDP and similar domains. We discuss our approach for translating a planning problem into a constraint satisfaction problem (CSP) and for representing and reasoning about structured objects and constraints over structures.

  16. Study Design and Percent Recoveries of Anthropogenic Organic Compounds With and Without the Addition of Ascorbic Acid to Preserve Water Samples Containing Free Chlorine, 2004-06

    USGS Publications Warehouse

    Valder, Joshua F.; Delzer, Gregory C.; Price, Curtis V.; Sandstrom, Mark W.

    2008-01-01

    The National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey (USGS) began implementing Source Water-Quality Assessments (SWQAs) in 2002 that focus on characterizing the quality of source water and finished water of aquifers and major rivers used by some of the larger community water systems in the United States. As used for SWQA studies, source water is the raw (ambient) water collected at the supply well prior to water treatment (for ground water) or the raw (ambient) water collected from the river near the intake (for surface water). Finished water is the water that is treated, which typically involves, in part, the addition of chlorine or other disinfection chemicals to remove pathogens, and is ready to be delivered to consumers. Finished water is collected before the water enters the distribution system. This report describes the study design and percent recoveries of anthropogenic organic compounds (AOCs) with and without the addition of ascorbic acid to preserve water samples containing free chlorine. The percent recoveries were determined by using analytical results from a laboratory study conducted in 2004 by the USGS's National Water Quality Laboratory (NWQL) and from data collected during 2004-06 for a field study currently (2008) being conducted by the USGS's NAWQA Program. The laboratory study was designed to determine if preserving samples with ascorbic acid (quenching samples) adversely affects analytical performance under controlled conditions. During the laboratory study, eight samples of reagent water were spiked for each of five analytical schedules evaluated. Percent recoveries from these samples were then compared in two ways: (1) four quenched reagent spiked samples analyzed on day 0 were compared with four quenched reagent spiked samples analyzed on day 7 or 14, and (2) the combined eight quenched reagent spiked samples analyzed on day 0, 7, or 14 were compared with eight laboratory reagent spikes (LRSs). Percent

  17. Atom mapping with constraint programming.

    PubMed

    Mann, Martin; Nahar, Feras; Schnorr, Norah; Backofen, Rolf; Stadler, Peter F; Flamm, Christoph

    2014-01-01

    Chemical reactions are rearrangements of chemical bonds. Each atom in an educt molecule thus appears again in a specific position of one of the reaction products. This bijection between educt and product atoms is not reported by chemical reaction databases, however, so that the "Atom Mapping Problem" of finding this bijection is left as an important computational task for many practical applications in computational chemistry and systems biology. Elementary chemical reactions feature a cyclic imaginary transition state (ITS) that imposes additional restrictions on the bijection between educt and product atoms that are not taken into account by previous approaches. We demonstrate that Constraint Programming is well-suited to solving the Atom Mapping Problem in this setting. The performance of our approach is evaluated for a manually curated subset of chemical reactions from the KEGG database featuring various ITS cycle layouts and reaction mechanisms.

  18. Asteroseismic constraints for Gaia

    NASA Astrophysics Data System (ADS)

    Creevey, O. L.; Thévenin, F.

    2012-12-01

    Distances from the Gaia mission will no doubt improve our understanding of stellar physics by providing an excellent constraint on the luminosity of the star. However, it is also clear that high precision stellar properties from, for example, asteroseismology, will also provide a needed input constraint in order to calibrate the methods that Gaia will use, e.g. stellar models or GSP_Phot. For solar-like stars (F, G, K IV/V), asteroseismic data delivers at the least two very important quantities: (1) the average large frequency separation < Δ ν > and (2) the frequency corresponding to the maximum of the modulated-amplitude spectrum ν_{max}. Both of these quantities are related directly to stellar parameters (radius and mass) and in particular their combination (gravity and density). We show how the precision in < Δ ν >, ν_{max}, and atmospheric parameters T_{eff} and [Fe/H] affect the determination of gravity (log g) for a sample of well-known stars. We find that log g can be determined within less than 0.02 dex accuracy for our sample while considering precisions in the data expected for V˜12 stars from Kepler data. We also derive masses and radii which are accurate to within 1σ of the accepted values. This study validates the subsequent use of all of the available asteroseismic data on solar-like stars from the Kepler field (>500 IV/V stars) in order to provide a very important constraint for Gaia calibration of GSP_Phot} through the use of log g. We note that while we concentrate on IV/V stars, both the CoRoT and Kepler fields contain asteroseismic data on thousands of giant stars which will also provide useful calibration measures.

  19. Performance constraints in decathletes.

    PubMed

    Van Damme, Raoul; Wilson, Robbie S; Vanhooydonck, Bieke; Aerts, Peter

    2002-02-14

    Physical performance by vertebrates is thought to be constrained by trade-offs between antagonistic pairs of ecologically relevant traits and between conflicting specialist and generalist phenotypes, but there is surprisingly little evidence to support this reasoning. Here we analyse the performance of world-class athletes in standardized decathlon events and find that it is subject to both types of trade-off, after correction has been made for differences between athletes in general ability across all 10 events. These trade-offs may have imposed important constraints on the evolution of physical performance in humans and other vertebrates. PMID:11845199

  20. ELMs and constraints on the H-mode pedestal: peeling ballooning stability calculation and comparison with experiment

    NASA Astrophysics Data System (ADS)

    Snyder, P. B.; Wilson, H. R.; Ferron, J. R.; Lao, L. L.; Leonard, A. W.; Mossessian, D.; Murakami, M.; Osborne, T. H.; Turnbull, A. D.; Xu, X. Q.

    2004-02-01

    We review and test the peeling-ballooning model for edge localized modes (ELMs) and pedestal constraints, a model based upon theoretical analysis of magnetohydrodynamic (MHD) instabilities that can limit the pedestal height and drive ELMs. A highly efficient MHD stability code, ELITE, is used to calculate quantitative stability constraints on the pedestal, including constraints on the pedestal height. Because of the impact of collisionality on the bootstrap current, these pedestal constraints are dependent on the density and temperature separately, rather than simply on the pressure. ELITE stability calculations are directly compared with experimental data for a series of plasmas in which the density is varied and ELM characteristics change. In addition, a technique is developed whereby peeling-ballooning pedestal constraints are calculated as a function of key equilibrium parameters via ELITE calculations using series of model equilibria. This technique is used to successfully compare the expected pedestal height as a function of density, triangularity and plasma current with experimental data. Furthermore, the technique can be applied for parameter ranges beyond the purview of present experiments, and we present a brief projection of peeling-ballooning pedestal constraints for burning plasma tokamak designs.

  1. Higher derivative theories with constraints: exorcising Ostrogradski's ghost

    SciTech Connect

    Chen, Tai-jun; Lim, Eugene A.; Fasiello, Matteo; Tolley, Andrew J. E-mail: matte@case.edu E-mail: andrew.j.tolley@case.edu

    2013-02-01

    We prove that the linear instability in a non-degenerate higher derivative theory, the Ostrogradski instability, can only be removed by the addition of constraints if the original theory's phase space is reduced.

  2. On heterotic model constraints

    NASA Astrophysics Data System (ADS)

    Bouchard, Vincent; Donagi, Ron

    2008-08-01

    The constraints imposed on heterotic compactifications by global consistency and phenomenology seem to be very finely balanced. We show that weakening these constraints, as was proposed in some recent works, is likely to lead to frivolous results. In particular, we construct an infinite set of such frivolous models having precisely the massless spectrum of the MSSM and other quasi-realistic features. Only one model in this infinite collection (the one constructed in [8]) is globally consistent and supersymmetric. The others might be interpreted as being anomalous, or as non-supersymmetric models, or as local models that cannot be embedded in a global one. We also show that the strongly coupled model of [8] can be modified to a perturbative solution with stable SU(4) or SU(5) bundles in the hidden sector. We finally propose a detailed exploration of heterotic vacua involving bundles on Calabi-Yau threefolds with Bbb Z6 Wilson lines; we obtain many more frivolous solutions, but none that are globally consistent and supersymmetric at the string scale.

  3. Symbolic Constraint Maintenance Grid

    NASA Technical Reports Server (NTRS)

    James, Mark

    2006-01-01

    Version 3.1 of Symbolic Constraint Maintenance Grid (SCMG) is a software system that provides a general conceptual framework for utilizing pre-existing programming techniques to perform symbolic transformations of data. SCMG also provides a language (and an associated communication method and protocol) for representing constraints on the original non-symbolic data. SCMG provides a facility for exchanging information between numeric and symbolic components without knowing the details of the components themselves. In essence, it integrates symbolic software tools (for diagnosis, prognosis, and planning) with non-artificial-intelligence software. SCMG executes a process of symbolic summarization and monitoring of continuous time series data that are being abstractly represented as symbolic templates of information exchange. This summarization process enables such symbolic- reasoning computing systems as artificial- intelligence planning systems to evaluate the significance and effects of channels of data more efficiently than would otherwise be possible. As a result of the increased efficiency in representation, reasoning software can monitor more channels and is thus able to perform monitoring and control functions more effectively.

  4. Automated solar collector installation design

    DOEpatents

    Wayne, Gary; Frumkin, Alexander; Zaydman, Michael; Lehman, Scott; Brenner, Jules

    2014-08-26

    Embodiments may include systems and methods to create and edit a representation of a worksite, to create various data objects, to classify such objects as various types of pre-defined "features" with attendant properties and layout constraints. As part of or in addition to classification, an embodiment may include systems and methods to create, associate, and edit intrinsic and extrinsic properties to these objects. A design engine may apply of design rules to the features described above to generate one or more solar collectors installation design alternatives, including generation of on-screen and/or paper representations of the physical layout or arrangement of the one or more design alternatives.

  5. Statistical Techniques to Explore the Quality of Constraints in Constraint-Based Modeling Environments

    ERIC Educational Resources Information Center

    Gálvez, Jaime; Conejo, Ricardo; Guzmán, Eduardo

    2013-01-01

    One of the most popular student modeling approaches is Constraint-Based Modeling (CBM). It is an efficient approach that can be easily applied inside an Intelligent Tutoring System (ITS). Even with these characteristics, building new ITSs requires carefully designing the domain model to be taught because different sources of errors could affect…

  6. Relative constraints and evolution

    NASA Astrophysics Data System (ADS)

    Ochoa, Juan G. Diaz

    2014-03-01

    Several mathematical models of evolving systems assume that changes in the micro-states are constrained to the search of an optimal value in a local or global objective function. However, the concept of evolution requires a continuous change in the environment and species, making difficult the definition of absolute optimal values in objective functions. In this paper, we define constraints that are not absolute but relative to local micro-states, introducing a rupture in the invariance of the phase space of the system. This conceptual basis is useful to define alternative mathematical models for biological (or in general complex) evolving systems. We illustrate this concept with a modified Ising model, which can be useful to understand and model problems like the somatic evolution of cancer.

  7. An experimental substantiation of the design functions imposed on the additional system for passively flooding the core of a VVER reactor

    NASA Astrophysics Data System (ADS)

    Morozov, A. V.; Remizov, O. V.

    2012-05-01

    Results obtained from a research work on experimentally substantiating the serviceability of the additional system for passively flooding the core of a VVER reactor from the second-stage hydro accumulators are presented.

  8. Observational constraints on K-inflation models

    SciTech Connect

    Li, Sheng; Liddle, Andrew R. E-mail: a.liddle@sussex.ac.uk

    2012-10-01

    We extend the ModeCode software of Mortonson, Peiris and Easther [1] to enable numerical computation of perturbations in K-inflation models, where the scalar field no longer has a canonical kinetic term. Focussing on models where the kinetic and potential terms can be separated into a sum, we compute slow-roll predictions for various models and use these to verify the numerical code. A Markov chain Monte Carlo analysis is then used to impose constraints from WMAP7 data on the addition of a term quadratic in the kinetic energy to the Lagrangian of simple chaotic inflation models. For a quadratic potential, the data do not discriminate against addition of such a term, while for a quartic (λφ{sup 4}) potential inclusion of such a term is actually favoured. Overall, constraints on such a term from present data are found to be extremely weak.

  9. Evolutionary constraints or opportunities?

    PubMed

    Sharov, Alexei A

    2014-04-22

    Natural selection is traditionally viewed as a leading factor of evolution, whereas variation is assumed to be random and non-directional. Any order in variation is attributed to epigenetic or developmental constraints that can hinder the action of natural selection. In contrast I consider the positive role of epigenetic mechanisms in evolution because they provide organisms with opportunities for rapid adaptive change. Because the term "constraint" has negative connotations, I use the term "regulated variation" to emphasize the adaptive nature of phenotypic variation, which helps populations and species to survive and evolve in changing environments. The capacity to produce regulated variation is a phenotypic property, which is not described in the genome. Instead, the genome acts as a switchboard, where mostly random mutations switch "on" or "off" preexisting functional capacities of organism components. Thus, there are two channels of heredity: informational (genomic) and structure-functional (phenotypic). Functional capacities of organisms most likely emerged in a chain of modifications and combinations of more simple ancestral functions. The role of DNA has been to keep records of these changes (without describing the result) so that they can be reproduced in the following generations. Evolutionary opportunities include adjustments of individual functions, multitasking, connection between various components of an organism, and interaction between organisms. The adaptive nature of regulated variation can be explained by the differential success of lineages in macro-evolution. Lineages with more advantageous patterns of regulated variation are likely to produce more species and secure more resources (i.e., long-term lineage selection).

  10. Evolutionary constraints or opportunities?

    PubMed

    Sharov, Alexei A

    2014-09-01

    Natural selection is traditionally viewed as a leading factor of evolution, whereas variation is assumed to be random and non-directional. Any order in variation is attributed to epigenetic or developmental constraints that can hinder the action of natural selection. In contrast I consider the positive role of epigenetic mechanisms in evolution because they provide organisms with opportunities for rapid adaptive change. Because the term "constraint" has negative connotations, I use the term "regulated variation" to emphasize the adaptive nature of phenotypic variation, which helps populations and species to survive and evolve in changing environments. The capacity to produce regulated variation is a phenotypic property, which is not described in the genome. Instead, the genome acts as a switchboard, where mostly random mutations switch "on" or "off" preexisting functional capacities of organism components. Thus, there are two channels of heredity: informational (genomic) and structure-functional (phenotypic). Functional capacities of organisms most likely emerged in a chain of modifications and combinations of more simple ancestral functions. The role of DNA has been to keep records of these changes (without describing the result) so that they can be reproduced in the following generations. Evolutionary opportunities include adjustments of individual functions, multitasking, connection between various components of an organism, and interaction between organisms. The adaptive nature of regulated variation can be explained by the differential success of lineages in macro-evolution. Lineages with more advantageous patterns of regulated variation are likely to produce more species and secure more resources (i.e., long-term lineage selection).

  11. Neural constraints on learning

    PubMed Central

    Sadtler, Patrick T.; Quick, Kristin M.; Golub, Matthew D.; Chase, Steven M.; Ryu, Stephen I.; Tyler-Kabara, Elizabeth C.; Yu, Byron M.; Batista, Aaron P.

    2014-01-01

    Motor, sensory, and cognitive learning require networks of neurons to generate new activity patterns. Because some behaviors are easier to learn than others1,2, we wondered if some neural activity patterns are easier to generate than others. We asked whether the existing network constrains the patterns that a subset of its neurons is capable of exhibiting, and if so, what principles define the constraint. We employed a closed-loop intracortical brain-computer interface (BCI) learning paradigm in which Rhesus monkeys controlled a computer cursor by modulating neural activity patterns in primary motor cortex. Using the BCI paradigm, we could specify and alter how neural activity mapped to cursor velocity. At the start of each session, we observed the characteristic activity patterns of the recorded neural population. These patterns comprise a low-dimensional space (termed the intrinsic manifold, or IM) within the high-dimensional neural firing rate space. They presumably reflect constraints imposed by the underlying neural circuitry. We found that the animals could readily learn to proficiently control the cursor using neural activity patterns that were within the IM. However, animals were less able to learn to proficiently control the cursor using activity patterns that were outside of the IM. This result suggests that the existing structure of a network can shape learning. On the timescale of hours, it appears to be difficult to learn to generate neural activity patterns that are not consistent with the existing network structure. These findings offer a network-level explanation for the observation that we are more readily able to learn new skills when they are related to the skills that we already possess3,4. PMID:25164754

  12. The Nature of Credit Constraints and Human Capital. NBER Working Paper No. 13912

    ERIC Educational Resources Information Center

    Lochner, Lance J.; Monge-Naranjo, Alexander

    2008-01-01

    This paper studies the nature and impact of credit constraints in the market for human capital. We derive endogenous constraints from the design of government student loan programs and from the limited repayment incentives in private lending markets. These constraints imply cross-sectional patterns for schooling, ability, and family income that…

  13. The Optimization of Generalizability Studies with Resource Constraints.

    ERIC Educational Resources Information Center

    Marcoulides, George A.; Goldstein, Zvi

    1990-01-01

    A methodology for determining the optimal number of observations to use in a measurement design when resource constraints are imposed is presented. Two- and three-facet designs are outlined. Parallel closed form formulae can easily be determined for other designs. (TJH)

  14. Geochemical constraints on Earth's core composition

    NASA Astrophysics Data System (ADS)

    Siebert, Julien

    2016-04-01

    The density of the core as measured from seismic-wave velocities is lower (by 10-15%) than that of pure iron, and therefore the core must also contain some light elements. Geophysical and cosmochemical constraints indicate that obvious candidates for these light elements include silicon, oxygen, and sulfur. These elements have been studied extensively for the past 30 years but a joint solution fulfilling all the requirements imposed by cosmochemistry and geochemistry, seismology, and models of Earth's accretion and core formation is still a highly controversial subject. Here are presented new experimental data in geochemistry used to place constraints on Earth's core composition. Metal-silicate partitioning experiments were performed at pressures and temperatures directly similar to those that prevailed in a deep magma ocean in the early Earth. The results show that core formation can reconcile the observed concentrations of siderophile elements in the silicate mantle with geophysical constraints on light elements in the core. Partitioning results also lead to a core containing less than 1 wt.% of sulfur, inconsistent with a S-rich layer to account for the observed structure of the outer core. Additionally, isotopic fractionations in core formation experiments are presented. This experimental tool merging the fields of experimental petrology and isotope geochemistry represents a promising approach, providing new independent constraints on the nature of light elements in the core.

  15. Design, synthesis, and biological evaluation of simplified analogues of (+)-discodermolide. Additional insights on the importance of the diene, the C7 hydroxyl, and the lactone.

    PubMed

    Smith, Amos B; Xian, Ming

    2005-11-10

    [structure: see text] The design, synthesis, and biological evaluation of seven totally synthetic analogues of the antitumor agent (+)-discodermolide are reported. Saturation of the terminal diene system, alteration of the substituents on the lactone, and alkylation of the C7-hydroxyl group reveal significant structure-activity relationships.

  16. Evidence-Based Design for Project-Based Learning: A Case Study for a 50,000 SF Addition Dedicated to the New Tech Curriculum

    ERIC Educational Resources Information Center

    Moretti, Richard D.; Conte, Philip R.

    2012-01-01

    The Seaford School District, Seaford, Delaware, determined that a component of their "reinvention" of Seaford High School would be the creation of a New Tech Academy, affiliated with the New Tech Network and housed in an addition to that building. The New Tech Network, headquartered in Napa, California, is a rapidly growing association of New Tech…

  17. Sliding mode control based impact angle control guidance considering the seeker׳s field-of-view constraint.

    PubMed

    Wang, Xingliang; Zhang, Youan; Wu, Huali

    2016-03-01

    The problem of impact angle control guidance for a field-of-view constrained missile against non-maneuvering or maneuvering targets is solved by using the sliding mode control theory. The existing impact angle control guidance laws with field-of-view constraint are only applicable against stationary targets and most of them suffer abrupt-jumping of guidance command due to the application of additional guidance mode switching logic. In this paper, the field-of-view constraint is handled without using any additional switching logic. In particular, a novel time-varying sliding surface is first designed to achieve zero miss distance and zero impact angle error without violating the field-of-view constraint during the sliding mode phase. Then a control integral barrier Lyapunov function is used to design the reaching law so that the sliding mode can be reached within finite time and the field-of-view constraint is not violated during the reaching phase as well. A nonlinear extended state observer is constructed to estimate the disturbance caused by unknown target maneuver, and the undesirable chattering is alleviated effectively by using the estimation as a compensation item in the guidance law. The performance of the proposed guidance law is illustrated with simulations. PMID:26782929

  18. Sliding mode control based impact angle control guidance considering the seeker׳s field-of-view constraint.

    PubMed

    Wang, Xingliang; Zhang, Youan; Wu, Huali

    2016-03-01

    The problem of impact angle control guidance for a field-of-view constrained missile against non-maneuvering or maneuvering targets is solved by using the sliding mode control theory. The existing impact angle control guidance laws with field-of-view constraint are only applicable against stationary targets and most of them suffer abrupt-jumping of guidance command due to the application of additional guidance mode switching logic. In this paper, the field-of-view constraint is handled without using any additional switching logic. In particular, a novel time-varying sliding surface is first designed to achieve zero miss distance and zero impact angle error without violating the field-of-view constraint during the sliding mode phase. Then a control integral barrier Lyapunov function is used to design the reaching law so that the sliding mode can be reached within finite time and the field-of-view constraint is not violated during the reaching phase as well. A nonlinear extended state observer is constructed to estimate the disturbance caused by unknown target maneuver, and the undesirable chattering is alleviated effectively by using the estimation as a compensation item in the guidance law. The performance of the proposed guidance law is illustrated with simulations.

  19. On Constraints in Assembly Planning

    SciTech Connect

    Calton, T.L.; Jones, R.E.; Wilson, R.H.

    1998-12-17

    Constraints on assembly plans vary depending on product, assembly facility, assembly volume, and many other factors. Assembly costs and other measures to optimize vary just as widely. To be effective, computer-aided assembly planning systems must allow users to express the plan selection criteria that appIy to their products and production environments. We begin this article by surveying the types of user criteria, both constraints and quality measures, that have been accepted by assembly planning systems to date. The survey is organized along several dimensions, including strategic vs. tactical criteria; manufacturing requirements VS. requirements of the automated planning process itself and the information needed to assess compliance with each criterion. The latter strongly influences the efficiency of planning. We then focus on constraints. We describe a framework to support a wide variety of user constraints for intuitive and efficient assembly planning. Our framework expresses all constraints on a sequencing level, specifying orders and conditions on part mating operations in a number of ways. Constraints are implemented as simple procedures that either accept or reject assembly operations proposed by the planner. For efficiency, some constraints are supplemented with special-purpose modifications to the planner's algorithms. Fast replanning enables an interactive plan-view-constrain-replan cycle that aids in constraint discovery and documentation. We describe an implementation of the framework in a computer-aided assembly planning system and experiments applying the system to a number of complex assemblies, including one with 472 parts.

  20. Credit Constraints for Higher Education

    ERIC Educational Resources Information Center

    Solis, Alex

    2012-01-01

    This paper exploits a natural experiment that produces exogenous variation on credit access to determine the effect on college enrollment. The paper assess how important are credit constraints to explain the gap in college enrollment by family income, and what would be the gap if credit constraints are eliminated. Progress in college and dropout…

  1. Fixed Costs and Hours Constraints

    ERIC Educational Resources Information Center

    Johnson, William R.

    2011-01-01

    Hours constraints are typically identified by worker responses to questions asking whether they would prefer a job with more hours and more pay or fewer hours and less pay. Because jobs with different hours but the same rate of pay may be infeasible when there are fixed costs of employment or mandatory overtime premia, the constraint in those…

  2. Mission Implementation Constraints on Planetary Muon Radiography

    NASA Technical Reports Server (NTRS)

    Jones, Cathleen E.; Kedar, Sharon; Naudet, Charles; Webb, Frank

    2011-01-01

    Cost: Use heritage hardware, especially use a tested landing system to reduce cost (Phoenix or MSL EDL stage). The sky crane technology delivers higher mass to the surface and enables reaching targets at higher elevation, but at a higher mission cost. Rover vs. Stationary Lander: Rover-mounted instrument enables tomography, but the increased weight of the rover reduces the allowable payload weight. Mass is the critical design constraint for an instrument for a planetary mission. Many factors that are minor factors or do not enter into design considerations for terrestrial operation are important for a planetary application. (Landing site, diurnal temperature variation, instrument portability, shock/vibration)

  3. Generalizing Atoms in Constraint Logic

    NASA Technical Reports Server (NTRS)

    Page, C. David, Jr.; Frisch, Alan M.

    1991-01-01

    This paper studies the generalization of atomic formulas, or atoms, that are augmented with constraints on or among their terms. The atoms may also be viewed as definite clauses whose antecedents express the constraints. Atoms are generalized relative to a body of background information about the constraints. This paper first examines generalization of atoms with only monadic constraints. The paper develops an algorithm for the generalization task and discusses algorithm complexity. It then extends the algorithm to apply to atoms with constraints of arbitrary arity. The paper also presents semantic properties of the generalizations computed by the algorithms, making the algorithms applicable to such problems as abduction, induction, and knowledge base verification. The paper emphasizes the application to induction and presents a pac-learning result for constrained atoms.

  4. A Quasi-Experimental Study of Two Selected Units of the Industrial Arts Curriculum Project Materials to Determine the Measurable Additive Effects of a Unit on Design in Manfacturing Technology upon a Similar Unit on Design in Construction Technology.

    ERIC Educational Resources Information Center

    Kuwik, Paul David

    The purpose of the study was to determine whether exposing junior high school students to a unit on design in construction technology and to a unit on design in manufacturing technology significantly affects their achievement on a test measuring "Technological Principles of Design" when compared to a group of junior high school students exposed…

  5. A linearized theory method of constrained optimization for supersonic cruise wing design

    NASA Technical Reports Server (NTRS)

    Miller, D. S.; Carlson, H. W.; Middleton, W. D.

    1976-01-01

    A linearized theory wing design and optimization procedure which allows physical realism and practical considerations to be imposed as constraints on the optimum (least drag due to lift) solution is discussed and examples of application are presented. In addition to the usual constraints on lift and pitching moment, constraints are imposed on wing surface ordinates and wing upper surface pressure levels and gradients. The design procedure also provides the capability of including directly in the optimization process the effects of other aircraft components such as a fuselage, canards, and nacelles.

  6. Algorithms for reactions of nonholonomic constraints and servo-constraints

    NASA Astrophysics Data System (ADS)

    Slawianowski, J. J.

    Various procedures for deriving equations of motion of constrained mechanical systems are discussed and compared. A geometric interpretation of the procedures is given, stressing both linear and nonlinear nonholonomic constraints. Certain qualitative differences are analyzed between models of nonholonomic dynamics based on different procedures. Two algorithms of particular interest are: (1) the d'Alembert principle and its Appell-Tshetajev generalization, and (2) the variational Hamiltonian principle with subsidiary conditions. It is argued that the Hamiltonian principle, although not accepted in traditional technical applications, is more promising in generalizations concerning systems with higher differential constraints, or the more general functional constraints appearing in feedback and control systems.

  7. Level-Set Topology Optimization with Aeroelastic Constraints

    NASA Technical Reports Server (NTRS)

    Dunning, Peter D.; Stanford, Bret K.; Kim, H. Alicia

    2015-01-01

    Level-set topology optimization is used to design a wing considering skin buckling under static aeroelastic trim loading, as well as dynamic aeroelastic stability (flutter). The level-set function is defined over the entire 3D volume of a transport aircraft wing box. Therefore, the approach is not limited by any predefined structure and can explore novel configurations. The Sequential Linear Programming (SLP) level-set method is used to solve the constrained optimization problems. The proposed method is demonstrated using three problems with mass, linear buckling and flutter objective and/or constraints. A constraint aggregation method is used to handle multiple buckling constraints in the wing skins. A continuous flutter constraint formulation is used to handle difficulties arising from discontinuities in the design space caused by a switching of the critical flutter mode.

  8. Constraints and stability in vector theories with spontaneous Lorentz violation

    SciTech Connect

    Bluhm, Robert; Gagne, Nolan L.; Potting, Robertus; Vrublevskis, Arturs

    2008-06-15

    Vector theories with spontaneous Lorentz violation, known as bumblebee models, are examined in flat spacetime using a Hamiltonian constraint analysis. In some of these models, Nambu-Goldstone modes appear with properties similar to photons in electromagnetism. However, depending on the form of the theory, additional modes and constraints can appear that have no counterparts in electromagnetism. An examination of these constraints and additional degrees of freedom, including their nonlinear effects, is made for a variety of models with different kinetic and potential terms, and the results are compared with electromagnetism. The Hamiltonian constraint analysis also permits an investigation of the stability of these models. For certain bumblebee theories with a timelike vector, suitable restrictions of the initial-value solutions are identified that yield ghost-free models with a positive Hamiltonian. In each case, the restricted phase space is found to match that of electromagnetism in a nonlinear gauge.

  9. Evolutionary constraints or opportunities?

    PubMed Central

    Sharov, Alexei A.

    2014-01-01

    Natural selection is traditionally viewed as a leading factor of evolution, whereas variation is assumed to be random and non-directional. Any order in variation is attributed to epigenetic or developmental constraints that can hinder the action of natural selection. In contrast I consider the positive role of epigenetic mechanisms in evolution because they provide organisms with opportunities for rapid adaptive change. Because the term “constraint” has negative connotations, I use the term “regulated variation” to emphasize the adaptive nature of phenotypic variation, which helps populations and species to survive and evolve in changing environments. The capacity to produce regulated variation is a phenotypic property, which is not described in the genome. Instead, the genome acts as a switchboard, where mostly random mutations switch “on” or “off” preexisting functional capacities of organism components. Thus, there are two channels of heredity: informational (genomic) and structure-functional (phenotypic). Functional capacities of organisms most likely emerged in a chain of modifications and combinations of more simple ancestral functions. The role of DNA has been to keep records of these changes (without describing the result) so that they can be reproduced in the following generations. Evolutionary opportunities include adjustments of individual functions, multitasking, connection between various components of an organism, and interaction between organisms. The adaptive nature of regulated variation can be explained by the differential success of lineages in macro-evolution. Lineages with more advantageous patterns of regulated variation are likely to produce more species and secure more resources (i.e., long-term lineage selection). PMID:24769155

  10. Compilation of non-contemporaneous constraints

    SciTech Connect

    Wray, R.E. III; Laird, J.E.; Jones, R.M.

    1996-12-31

    Hierarchical execution of domain knowledge is a useful approach for intelligent, real-time systems in complex domains. In addition, well-known techniques for knowledge compilation allow the reorganization of knowledge hierarchies into more efficient forms. However, these techniques have been developed in the context of systems that work in static domains. Our investigations indicate that it is not straightforward to apply knowledge compilation methods for hierarchical knowledge to systems that generate behavior in dynamic environments. One particular problem involves the compilation of non-contemporaneous constraints. This problem arises when a training instance dynamically changes during execution. After defining the problem, we analyze several theoretical approaches that address non-contemporaneous constraints. We have implemented the most promising of these alternatives within Soar, a software architecture for performance and learning. Our results demonstrate that the proposed solutions eliminate the problem in some situations and suggest that knowledge compilation methods are appropriate for interactive environments.

  11. Constraint Embedding Technique for Multibody System Dynamics

    NASA Technical Reports Server (NTRS)

    Woo, Simon S.; Cheng, Michael K.

    2011-01-01

    Multibody dynamics play a critical role in simulation testbeds for space missions. There has been a considerable interest in the development of efficient computational algorithms for solving the dynamics of multibody systems. Mass matrix factorization and inversion techniques and the O(N) class of forward dynamics algorithms developed using a spatial operator algebra stand out as important breakthrough on this front. Techniques such as these provide the efficient algorithms and methods for the application and implementation of such multibody dynamics models. However, these methods are limited only to tree-topology multibody systems. Closed-chain topology systems require different techniques that are not as efficient or as broad as those for tree-topology systems. The closed-chain forward dynamics approach consists of treating the closed-chain topology as a tree-topology system subject to additional closure constraints. The resulting forward dynamics solution consists of: (a) ignoring the closure constraints and using the O(N) algorithm to solve for the free unconstrained accelerations for the system; (b) using the tree-topology solution to compute a correction force to enforce the closure constraints; and (c) correcting the unconstrained accelerations with correction accelerations resulting from the correction forces. This constraint-embedding technique shows how to use direct embedding to eliminate local closure-loops in the system and effectively convert the system back to a tree-topology system. At this point, standard tree-topology techniques can be brought to bear on the problem. The approach uses a spatial operator algebra approach to formulating the equations of motion. The operators are block-partitioned around the local body subgroups to convert them into aggregate bodies. Mass matrix operator factorization and inversion techniques are applied to the reformulated tree-topology system. Thus in essence, the new technique allows conversion of a system with

  12. Federal constraints: earned or unearned?

    PubMed

    Chalkley, D T

    1977-08-01

    The author discusses the evolution of federal constraints on medical, behavioral, and social science research. There has been only one court decision related to behavioral research and none in medical research. The burden of consent procedures can be lightened somewhat by careful consideration of the potential risks and nature of the research; questions are presented that can be used to determine whether constraints apply. The author notes that although there are good reasons for regulations in both behavioral and medical research, the appropriateness of current and proposed constraints is still a matter of debate.

  13. Resource allocation using constraint propagation

    NASA Technical Reports Server (NTRS)

    Rogers, John S.

    1990-01-01

    The concept of constraint propagation was discussed. Performance increases are possible with careful application of these constraint mechanisms. The degree of performance increase is related to the interdependence of the different activities resource usage. Although this method of applying constraints to activities and resources is often beneficial, it is obvious that this is no panacea cure for the computational woes that are experienced by dynamic resource allocation and scheduling problems. A combined effort for execution optimization in all areas of the system during development and the selection of the appropriate development environment is still the best method of producing an efficient system.

  14. A Comparative Study of Randomized Constraint Solvers for Random-Symbolic Testing

    NASA Technical Reports Server (NTRS)

    Takaki, Mitsuo; Cavalcanti, Diego; Gheyi, Rohit; Iyoda, Juliano; dAmorim, Marcelo; Prudencio, Ricardo

    2009-01-01

    The complexity of constraints is a major obstacle for constraint-based software verification. Automatic constraint solvers are fundamentally incomplete: input constraints often build on some undecidable theory or some theory the solver does not support. This paper proposes and evaluates several randomized solvers to address this issue. We compare the effectiveness of a symbolic solver (CVC3), a random solver, three hybrid solvers (i.e., mix of random and symbolic), and two heuristic search solvers. We evaluate the solvers on two benchmarks: one consisting of manually generated constraints and another generated with a concolic execution of 8 subjects. In addition to fully decidable constraints, the benchmarks include constraints with non-linear integer arithmetic, integer modulo and division, bitwise arithmetic, and floating-point arithmetic. As expected symbolic solving (in particular, CVC3) subsumes the other solvers for the concolic execution of subjects that only generate decidable constraints. For the remaining subjects the solvers are complementary.

  15. Evaluating the Combined Toxicity of Cu and ZnO Nanoparticles: Utility of the Concept of Additivity and a Nested Experimental Design.

    PubMed

    Liu, Yang; Baas, Jan; Peijnenburg, Willie J G M; Vijver, Martina G

    2016-05-17

    Little is understood regarding the effects of mixtures of different metal-based nanoparticles (NPs). Using concentration-addition (CA) and independent-action (IA) models, we evaluated the combined toxicity of Cu and ZnO NPs based on five nested combinations, i.e., Cu(NO3)2-CuNPs, Zn(NO3)2-ZnONPs, Cu(NO3)2-ZnONPs, Zn(NO3)2-CuNPs, and CuNPs-ZnONPs on root elongation of Lactuca sativa L. The CA and IA models performed equally well in estimating the toxicity of mixtures of Cu(NO3)2-CuNPs, Zn(NO3)2-ZnONPs, and Zn(NO3)2-CuNPs, whereas the IA model was significantly better for fitting the data of Cu(NO3)2-ZnONPs and CuNPs-ZnONPs mixtures. Dissolved Cu proved to be the most toxic metal species to lettuce roots in the tests, followed by Cu NPs, dissolved Zn, and ZnO NPs, respectively. An antagonistic effect was observed for ZnO NPs on the toxicity of Cu NPs. This antagonistic effect is expected to be the result of interactions between dissolved Cu and dissolved Zn, particulate Zn and dissolved Zn, particulate Cu and dissolved Zn, and between particulate Zn and dissolved Cu. In general terms, assuming additivity gives a first indication of the combined toxicity with soluble and insoluble metal particles, both being important in driving the toxicity of metal-based NPs to higher plants. PMID:27070131

  16. Maximum life spiral bevel reduction design

    NASA Technical Reports Server (NTRS)

    Savage, M.; Prasanna, M. G.; Coe, H. H.

    1992-01-01

    Optimization is applied to the design of a spiral bevel gear reduction for maximum life at a given size. A modified feasible directions search algorithm permits a wide variety of inequality constraints and exact design requirements to be met with low sensitivity to initial values. Gear tooth bending strength and minimum contact ratio under load are included in the active constraints. The optimal design of the spiral bevel gear reduction includes the selection of bearing and shaft proportions in addition to gear mesh parameters. System life is maximized subject to a fixed backcone distance of the spiral bevel gear set for a specified speed reduction, shaft angle, input torque, and power. Design examples show the influence of the bearing lives on the gear parameters in the optimal configurations. For a fixed back-cone distance, optimal designs with larger shaft angles have larger service lives.

  17. Weighted constraints in generative linguistics.

    PubMed

    Pater, Joe

    2009-08-01

    Harmonic Grammar (HG) and Optimality Theory (OT) are closely related formal frameworks for the study of language. In both, the structure of a given language is determined by the relative strengths of a set of constraints. They differ in how these strengths are represented: as numerical weights (HG) or as ranks (OT). Weighted constraints have advantages for the construction of accounts of language learning and other cognitive processes, partly because they allow for the adaptation of connectionist and statistical models. HG has been little studied in generative linguistics, however, largely due to influential claims that weighted constraints make incorrect predictions about the typology of natural languages, predictions that are not shared by the more popular OT. This paper makes the case that HG is in fact a promising framework for typological research, and reviews and extends the existing arguments for weighted over ranked constraints.

  18. Next-generation sequencing studies guide the design of pyrrole-imidazole polyamides with improved binding specificity by the addition of β-alanine.

    PubMed

    Anandhakumar, Chandran; Li, Yue; Kizaki, Seiichiro; Pandian, Ganesh N; Hashiya, Kaori; Bando, Toshikazu; Sugiyama, Hiroshi

    2014-12-15

    The identification of binding sites for small molecules in genomic DNA is important in various applications. Previously, we demonstrated rapid transcriptional activation by our small molecule SAHA-PIP. However, it was not clear whether the strong biological effects exerted by SAHA-PIP were attributable to its binding specificity. Here, we used high-throughput sequencing (Bind-n-seq) to determine the binding specificity of SAHA-PIPs. Sequence specificity bias was determined for SAHA-PIPs (3 and 4), and this showed enhanced 6 bp sequence-specific binding compared with hairpin PIPs (1 and 2). This finding allowed us to investigate the role of the β-alanine that links SAHA to PIP, and led in turn to the design of ββ-PIPs (5 and 6), which showed enhanced binding specificity. Overall, we demonstrated the importance of β-moieties for the binding specificity of PIPs and the use of cost-effective high-throughput screening of these small molecules for binding to the DNA minor groove.

  19. Fluid convection, constraint and causation

    PubMed Central

    Bishop, Robert C.

    2012-01-01

    Complexity—nonlinear dynamics for my purposes in this essay—is rich with metaphysical and epistemological implications but is receiving sustained philosophical analysis only recently. I will explore some of the subtleties of causation and constraint in Rayleigh–Bénard convection as an example of a complex phenomenon, and extract some lessons for further philosophical reflection on top-down constraint and causation particularly with respect to causal foundationalism. PMID:23386955

  20. Flexible formation configuration for terrain following flight: Formation keeping constraints

    NASA Astrophysics Data System (ADS)

    Latyshev, Simon

    This work suggests a control method for the terrain-following formation motion of a group of communicating autonomous agents. The presented approach centers on defining a suitable set of constraints for formation keeping task that shall be fulfilled while agents are negotiating an unknown terrain toward the predefined goal location. It allows agents to maintain a general geometric formation shape, while allowing each individual formation member freedom of maneuver, required for terrain collision free motion. Formation structure is defined with the use of virtual leader. Formation keeping constraints are defined with plane surfaces, specified relative to position and navigation vector of the virtual leader. Formation navigation and guidance constraints are defined using navigation vectors of formation members and the virtual leader. Alternative designs for the constraints derived with parabolic, cone, and cylindrical surfaces are considered. Formation control is derived using the Udwadia-Kalaba equation, following corresponding approach to the development of control methods for constraint based dynamical systems, including leader-follower systems defined using geometric constraints. Approach to terrain following motion requiring agents to stay within bounds of cylindrical corridor volumes built around their respective navigation vectors is assumed. Individual formation primitives and multi-level, hierarchical, formation structures are considered. Simulations, based on three degrees of freedom nonlinear model of an agent, performed using Mathematica and specifically developed combined Maya-Mathematica modeling and simulation system, demonstrate that a flexible terrain following formation motion is achieved with the presented sets of constraints.

  1. Phonotactic Constraints Are Activated across Languages in Bilinguals

    PubMed Central

    Freeman, Max R.; Blumenfeld, Henrike K.; Marian, Viorica

    2016-01-01

    During spoken language comprehension, auditory input activates a bilingual’s two languages in parallel based on phonological representations that are shared across languages. However, it is unclear whether bilinguals access phonotactic constraints from the non-target language during target language processing. For example, in Spanish, words with s+ consonant onsets cannot exist, and phonotactic constraints call for epenthesis (addition of a vowel, e.g., stable/estable). Native Spanish speakers may produce English words such as estudy (“study”) with epenthesis, suggesting that these bilinguals apply Spanish phonotactic constraints when speaking English. The present study is the first to examine whether bilinguals access Spanish phonotactic constraints during English comprehension. In an English cross-modal priming lexical decision task, Spanish–English bilinguals and English monolinguals heard English cognate and non-cognate primes containing s+ consonant onsets or controls without s+ onsets, followed by a lexical decision on visual targets with the /e/ phonotactic constraint or controls without /e/. Results revealed that bilinguals were faster to respond to /es/ non-word targets preceded by s+ cognate primes and /es/ and /e/ non-word targets preceded by s+ non-cognate primes, confirming that English primes containing s+ onsets activated Spanish phonotactic constraints. These findings are discussed within current accounts of parallel activation of two languages during bilingual spoken language comprehension, which may be expanded to include activation of phonotactic constraints from the irrelevant language. PMID:27242615

  2. Phonotactic Constraints Are Activated across Languages in Bilinguals.

    PubMed

    Freeman, Max R; Blumenfeld, Henrike K; Marian, Viorica

    2016-01-01

    During spoken language comprehension, auditory input activates a bilingual's two languages in parallel based on phonological representations that are shared across languages. However, it is unclear whether bilinguals access phonotactic constraints from the non-target language during target language processing. For example, in Spanish, words with s+ consonant onsets cannot exist, and phonotactic constraints call for epenthesis (addition of a vowel, e.g., stable/estable). Native Spanish speakers may produce English words such as estudy ("study") with epenthesis, suggesting that these bilinguals apply Spanish phonotactic constraints when speaking English. The present study is the first to examine whether bilinguals access Spanish phonotactic constraints during English comprehension. In an English cross-modal priming lexical decision task, Spanish-English bilinguals and English monolinguals heard English cognate and non-cognate primes containing s+ consonant onsets or controls without s+ onsets, followed by a lexical decision on visual targets with the /e/ phonotactic constraint or controls without /e/. Results revealed that bilinguals were faster to respond to /es/ non-word targets preceded by s+ cognate primes and /es/ and /e/ non-word targets preceded by s+ non-cognate primes, confirming that English primes containing s+ onsets activated Spanish phonotactic constraints. These findings are discussed within current accounts of parallel activation of two languages during bilingual spoken language comprehension, which may be expanded to include activation of phonotactic constraints from the irrelevant language. PMID:27242615

  3. Hydrogeologic Constraints on Yucatan's Development.

    PubMed

    Doehring, D O; Butler, J H

    1974-11-15

    The Republic of Mexico has an ambitious and effective national water program. The Secretaria de Recursos Hidraulicos (SRH), whose director has cabinet rank in the federal government, is one of the most professionally distinguished government agencies of its kind in the Americas. Resources for the Future, Inc., has been assisting the World Bank with a water planning study which the Bank is undertaking jointly with the Mexican government. The study is intended to provide guidelines for the development of government policies and projects designed to bring about the most efficient use of Mexico's water resources. However, to date, their study has not been directed toward the growing problems of the northern Yucatáan Peninsula which are discussed here. LeGrand (13) suggested that man has inherited a harsh environment in carbonate terranes. In the case of the northern Yucatán Peninsula, the physical environment creates a set of hydrogeologic constraints to future economic and social development. Planning for intermediate and long-range land use on the peninsula must be related directly to the limited and fragile groundwater source. Continued contamination will make future aquifer management a difficult challenge for federal, state, and territorial agencies. We conclude that any strategy for long-range land use in the study area should include establishment of a regional aquifermonitoring network for long-term measurements of key hydrogeologic parameters, including precipitation, evapotranspiration, water table elevations, and water quality. Information from this network would flow into a central facility for storage, interpretation, and analysis. At present the SRH is collecting some of these data. Expansion of the existing program to provide sound information for regional planning will greatly benefit present as well as future generations. If such a program is implemented, it will represent a model for regional planning in other tropical and subtropical karstic

  4. Breaking evolutionary constraint with a tradeoff ratchet

    PubMed Central

    de Vos, Marjon G. J.; Dawid, Alexandre; Sunderlikova, Vanda; Tans, Sander J.

    2015-01-01

    Epistatic interactions can frustrate and shape evolutionary change. Indeed, phenotypes may fail to evolve when essential mutations are only accessible through positive selection if they are fixed simultaneously. How environmental variability affects such constraints is poorly understood. Here, we studied genetic constraints in fixed and fluctuating environments using the Escherichia coli lac operon as a model system for genotype–environment interactions. We found that, in different fixed environments, all trajectories that were reconstructed by applying point mutations within the transcription factor–operator interface became trapped at suboptima, where no additional improvements were possible. Paradoxically, repeated switching between these same environments allows unconstrained adaptation by continuous improvements. This evolutionary mode is explained by pervasive cross-environmental tradeoffs that reposition the peaks in such a way that trapped genotypes can repeatedly climb ascending slopes and hence, escape adaptive stasis. Using a Markov approach, we developed a mathematical framework to quantify the landscape-crossing rates and show that this ratchet-like adaptive mechanism is robust in a wide spectrum of fluctuating environments. Overall, this study shows that genetic constraints can be overcome by environmental change and that cross-environmental tradeoffs do not necessarily impede but also, can facilitate adaptive evolution. Because tradeoffs and environmental variability are ubiquitous in nature, we speculate this evolutionary mode to be of general relevance. PMID:26567153

  5. Managing Urban School System Resources: New Procedures, Addition Actors.

    ERIC Educational Resources Information Center

    Hentschke, Guilbert C.

    In recent years urban school systems have had to face unusually severe economic constraints. In the process of adjusting to these constraints, urban systems will likely seek new ways to reallocate existing resources and will undertake more cooperative ventures with other organizational entities to gain access to additional resources. Four…

  6. Architecture, constraints, and behavior

    PubMed Central

    Doyle, John C.; Csete, Marie

    2011-01-01

    This paper aims to bridge progress in neuroscience involving sophisticated quantitative analysis of behavior, including the use of robust control, with other relevant conceptual and theoretical frameworks from systems engineering, systems biology, and mathematics. Familiar and accessible case studies are used to illustrate concepts of robustness, organization, and architecture (modularity and protocols) that are central to understanding complex networks. These essential organizational features are hidden during normal function of a system but are fundamental for understanding the nature, design, and function of complex biologic and technologic systems. PMID:21788505

  7. Molecular and cellular constraints on proteins

    NASA Astrophysics Data System (ADS)

    Kortemme, Tanja

    Engineering proteins with new sequences, structures and functions has many exciting practical applications, and provides new ways to dissect design principles for function. Recent successes in computational protein design provide a cause for optimism. Yet many functions are currently too complex to engineer predictively, and successful design of new biological activities also requires an understanding of the functional pressures acting on proteins in the context of cells and organisms. I will present two vignettes describing our progress with dissecting both molecular and cellular constraints on protein function. In the first, we characterized the cost and benefit of protein production upon sequence perturbations in a classic system for gene regulation, the lac operon. Our results were unexpected in light of the common assumption that the dominant fitness costs are due to protein expression. Instead, we discovered a direct linear relationship between cost and lacpermease activity, not protein or mRNA production. The magnitude of the cost of permease activity, relative to protein production, has consequences for regulation. Our model predicts an advantage of direct regulation of protein activity (not just expression), providing a new explanation for the long-known mechanism of ``inducer exclusion'' that inhibits transport through the permease. Similar pressures and cost/benefit tradeoffs may be key to engineering synthetic systems with improved fitness. In the second vignette, I will describe our recent efforts to develop computational approaches that predict protein sequences consistent with multiple functional conformations. We expect such ``multi-constraint'' models to improve predictions of functional sequences determined by deep mutational scanning in bacteria, to provide insights into how the balance between functional conformations shapes sequence space, and to highlight molecular and cellular constraints that cannot be captured by the model.

  8. Designing structures for dynamical properties via natural frequencies separation. Application to tensegrity structures design

    NASA Astrophysics Data System (ADS)

    Sultan, Cornel

    2009-05-01

    The design of structures for dynamic properties is addressed by placing conditions on the separation between natural frequencies. Additional constraints, like lower and upper bounds on the natural frequencies, are also included. A fast numerical algorithm that exploits the mathematical structure of the resulting problem is developed. Examples of the algorithm's application to tensegrity structures design are presented and the connection between natural frequencies separation and proportional damping approximation is analyzed.

  9. Modeling Multibody Stage Separation Dynamics Using Constraint Force Equation Methodology

    NASA Technical Reports Server (NTRS)

    Tartabini, Paul V.; Roithmayr, Carlos M.; Toniolo, Matthew D.; Karlgaard, Christopher D.; Pamadi, Bandu N.

    2011-01-01

    This paper discusses the application of the constraint force equation methodology and its implementation for multibody separation problems using three specially designed test cases. The first test case involves two rigid bodies connected by a fixed joint, the second case involves two rigid bodies connected with a universal joint, and the third test case is that of Mach 7 separation of the X-43A vehicle. For the first two cases, the solutions obtained using the constraint force equation method compare well with those obtained using industry- standard benchmark codes. For the X-43A case, the constraint force equation solutions show reasonable agreement with the flight-test data. Use of the constraint force equation method facilitates the analysis of stage separation in end-to-end simulations of launch vehicle trajectories

  10. Qualitative Reasoning for Additional Die Casting Applications

    SciTech Connect

    R. Allen Miller; Dehua Cui; Yuming Ma

    2003-05-28

    If manufacturing incompatibility of a product can be evaluated at the early product design stage, the designers can modify their design to reduce the effect of potential manufacturing problems. This will result in fewer manufacturing problems, less redsign, less expensive tooling, lower cost, better quality, and shorter development time. For a given design, geometric reasoning can predict qualitatively the behaviors of a physical manufacturing process by representing and reasoning with incomplete knowledge of the physical phenomena. It integrates a design with manufacturing processes to help designers simultaneously consider design goals and manufacturing constraints during the early design stage. The geometric reasoning approach can encourage design engineers to qualitatively evaluate the compatibility of their design with manufacturing limitations and requirements.

  11. Genetic constraints predict evolutionary divergence in Dalechampia blossoms

    PubMed Central

    Bolstad, Geir H.; Hansen, Thomas F.; Pélabon, Christophe; Falahati-Anbaran, Mohsen; Pérez-Barrales, Rocío; Armbruster, W. Scott

    2014-01-01

    If genetic constraints are important, then rates and direction of evolution should be related to trait evolvability. Here we use recently developed measures of evolvability to test the genetic constraint hypothesis with quantitative genetic data on floral morphology from the Neotropical vine Dalechampia scandens (Euphorbiaceae). These measures were compared against rates of evolution and patterns of divergence among 24 populations in two species in the D. scandens species complex. We found clear evidence for genetic constraints, particularly among traits that were tightly phenotypically integrated. This relationship between evolvability and evolutionary divergence is puzzling, because the estimated evolvabilities seem too large to constitute real constraints. We suggest that this paradox can be explained by a combination of weak stabilizing selection around moving adaptive optima and small realized evolvabilities relative to the observed additive genetic variance. PMID:25002700

  12. Genetic constraints predict evolutionary divergence in Dalechampia blossoms.

    PubMed

    Bolstad, Geir H; Hansen, Thomas F; Pélabon, Christophe; Falahati-Anbaran, Mohsen; Pérez-Barrales, Rocío; Armbruster, W Scott

    2014-08-19

    If genetic constraints are important, then rates and direction of evolution should be related to trait evolvability. Here we use recently developed measures of evolvability to test the genetic constraint hypothesis with quantitative genetic data on floral morphology from the Neotropical vine Dalechampia scandens (Euphorbiaceae). These measures were compared against rates of evolution and patterns of divergence among 24 populations in two species in the D. scandens species complex. We found clear evidence for genetic constraints, particularly among traits that were tightly phenotypically integrated. This relationship between evolvability and evolutionary divergence is puzzling, because the estimated evolvabilities seem too large to constitute real constraints. We suggest that this paradox can be explained by a combination of weak stabilizing selection around moving adaptive optima and small realized evolvabilities relative to the observed additive genetic variance. PMID:25002700

  13. Combined constraints on holographic bosonic technicolor

    SciTech Connect

    Carone, Christopher D.; Primulando, Reinard

    2010-07-01

    We consider a model of strong electroweak symmetry breaking in which the expectation value of an additional, possibly composite, scalar field is responsible for the generation of fermion masses. The dynamics of the strongly coupled sector is defined and studied via its holographic dual, and does not correspond to a simple, scaled-up version of QCD. We consider the bounds from perturbative unitarity, the S parameter, and the mass of the Higgs-like scalar. We show that the combination of these constraints leaves a relatively limited region of parameter space viable, and suggests the qualitative features of the model that might be probed at the LHC.

  14. Powered Descent Guidance with General Thrust-Pointing Constraints

    NASA Technical Reports Server (NTRS)

    Carson, John M., III; Acikmese, Behcet; Blackmore, Lars

    2013-01-01

    The Powered Descent Guidance (PDG) algorithm and software for generating Mars pinpoint or precision landing guidance profiles has been enhanced to incorporate thrust-pointing constraints. Pointing constraints would typically be needed for onboard sensor and navigation systems that have specific field-of-view requirements to generate valid ground proximity and terrain-relative state measurements. The original PDG algorithm was designed to enforce both control and state constraints, including maximum and minimum thrust bounds, avoidance of the ground or descent within a glide slope cone, and maximum speed limits. The thrust-bound and thrust-pointing constraints within PDG are non-convex, which in general requires nonlinear optimization methods to generate solutions. The short duration of Mars powered descent requires guaranteed PDG convergence to a solution within a finite time; however, nonlinear optimization methods have no guarantees of convergence to the global optimal or convergence within finite computation time. A lossless convexification developed for the original PDG algorithm relaxed the non-convex thrust bound constraints. This relaxation was theoretically proven to provide valid and optimal solutions for the original, non-convex problem within a convex framework. As with the thrust bound constraint, a relaxation of the thrust-pointing constraint also provides a lossless convexification that ensures the enhanced relaxed PDG algorithm remains convex and retains validity for the original nonconvex problem. The enhanced PDG algorithm provides guidance profiles for pinpoint and precision landing that minimize fuel usage, minimize landing error to the target, and ensure satisfaction of all position and control constraints, including thrust bounds and now thrust-pointing constraints.

  15. Developmental constraints on behavioural flexibility

    PubMed Central

    Holekamp, Kay E.; Swanson, Eli M.; Van Meter, Page E.

    2013-01-01

    We suggest that variation in mammalian behavioural flexibility not accounted for by current socioecological models may be explained in part by developmental constraints. From our own work, we provide examples of constraints affecting variation in behavioural flexibility, not only among individuals, but also among species and higher taxonomic units. We first implicate organizational maternal effects of androgens in shaping individual differences in aggressive behaviour emitted by female spotted hyaenas throughout the lifespan. We then compare carnivores and primates with respect to their locomotor and craniofacial adaptations. We inquire whether antagonistic selection pressures on the skull might impose differential functional constraints on evolvability of skulls and brains in these two orders, thus ultimately affecting behavioural flexibility in each group. We suggest that, even when carnivores and primates would theoretically benefit from the same adaptations with respect to behavioural flexibility, carnivores may nevertheless exhibit less behavioural flexibility than primates because of constraints imposed by past adaptations in the morphology of the limbs and skull. Phylogenetic analysis consistent with this idea suggests greater evolutionary lability in relative brain size within families of primates than carnivores. Thus, consideration of developmental constraints may help elucidate variation in mammalian behavioural flexibility. PMID:23569298

  16. Developmental constraints on behavioural flexibility.

    PubMed

    Holekamp, Kay E; Swanson, Eli M; Van Meter, Page E

    2013-05-19

    We suggest that variation in mammalian behavioural flexibility not accounted for by current socioecological models may be explained in part by developmental constraints. From our own work, we provide examples of constraints affecting variation in behavioural flexibility, not only among individuals, but also among species and higher taxonomic units. We first implicate organizational maternal effects of androgens in shaping individual differences in aggressive behaviour emitted by female spotted hyaenas throughout the lifespan. We then compare carnivores and primates with respect to their locomotor and craniofacial adaptations. We inquire whether antagonistic selection pressures on the skull might impose differential functional constraints on evolvability of skulls and brains in these two orders, thus ultimately affecting behavioural flexibility in each group. We suggest that, even when carnivores and primates would theoretically benefit from the same adaptations with respect to behavioural flexibility, carnivores may nevertheless exhibit less behavioural flexibility than primates because of constraints imposed by past adaptations in the morphology of the limbs and skull. Phylogenetic analysis consistent with this idea suggests greater evolutionary lability in relative brain size within families of primates than carnivores. Thus, consideration of developmental constraints may help elucidate variation in mammalian behavioural flexibility. PMID:23569298

  17. Developmental constraints on behavioural flexibility.

    PubMed

    Holekamp, Kay E; Swanson, Eli M; Van Meter, Page E

    2013-05-19

    We suggest that variation in mammalian behavioural flexibility not accounted for by current socioecological models may be explained in part by developmental constraints. From our own work, we provide examples of constraints affecting variation in behavioural flexibility, not only among individuals, but also among species and higher taxonomic units. We first implicate organizational maternal effects of androgens in shaping individual differences in aggressive behaviour emitted by female spotted hyaenas throughout the lifespan. We then compare carnivores and primates with respect to their locomotor and craniofacial adaptations. We inquire whether antagonistic selection pressures on the skull might impose differential functional constraints on evolvability of skulls and brains in these two orders, thus ultimately affecting behavioural flexibility in each group. We suggest that, even when carnivores and primates would theoretically benefit from the same adaptations with respect to behavioural flexibility, carnivores may nevertheless exhibit less behavioural flexibility than primates because of constraints imposed by past adaptations in the morphology of the limbs and skull. Phylogenetic analysis consistent with this idea suggests greater evolutionary lability in relative brain size within families of primates than carnivores. Thus, consideration of developmental constraints may help elucidate variation in mammalian behavioural flexibility.

  18. Design

    ERIC Educational Resources Information Center

    Buchanan, Richard; Cross, Nigel; Durling, David; Nelson, Harold; Owen, Charles; Valtonen, Anna; Boling, Elizabeth; Gibbons, Andrew; Visscher-Voerman, Irene

    2013-01-01

    Scholars representing the field of design were asked to identify what they considered to be the most exciting and imaginative work currently being done in their field, as well as how that work might change our understanding. The scholars included Richard Buchanan, Nigel Cross, David Durling, Harold Nelson, Charles Owen, and Anna Valtonen. Scholars…

  19. Multisensory constraints on awareness

    PubMed Central

    Deroy, Ophelia; Chen, Yi-Chuan; Spence, Charles

    2014-01-01

    Given that multiple senses are often stimulated at the same time, perceptual awareness is most likely to take place in multisensory situations. However, theories of awareness are based on studies and models established for a single sense (mostly vision). Here, we consider the methodological and theoretical challenges raised by taking a multisensory perspective on perceptual awareness. First, we consider how well tasks designed to study unisensory awareness perform when used in multisensory settings, stressing that studies using binocular rivalry, bistable figure perception, continuous flash suppression, the attentional blink, repetition blindness and backward masking can demonstrate multisensory influences on unisensory awareness, but fall short of tackling multisensory awareness directly. Studies interested in the latter phenomenon rely on a method of subjective contrast and can, at best, delineate conditions under which individuals report experiencing a multisensory object or two unisensory objects. As there is not a perfect match between these conditions and those in which multisensory integration and binding occur, the link between awareness and binding advocated for visual information processing needs to be revised for multisensory cases. These challenges point at the need to question the very idea of multisensory awareness. PMID:24639579

  20. Genetic map construction with constraints

    SciTech Connect

    Clark, D.A.; Rawlings, C.J.; Soursenot, S.

    1994-12-31

    A pilot program, CME, is described for generating a physical genetic map from hybridization fingerprinting data. CME is implemented in the parallel constraint logic programming language ElipSys. The features of constraint logic programming are used to enable the integration of preexisting mapping information (partial probe orders from cytogenetic maps and local physical maps) into the global map generation process, while parallelism enables the search space to be traversed more efficiently. CME was tested using data from chromosome 2 of Schizosaccharomyces pombe and was found able to generate maps as well as (and sometimes better than) a more traditional method. This paper illustrates the practical benefits of using a symbolic logic programming language and shows that the features of constraint handling and parallel execution bring the development of practical systems based on Al programming technologies nearer to being a reality.

  1. Symmetry constraint for foreground extraction.

    PubMed

    Fu, Huazhu; Cao, Xiaochun; Tu, Zhuowen; Lin, Dongdai

    2014-05-01

    Symmetry as an intrinsic shape property is often observed in natural objects. In this paper, we discuss how explicitly taking into account the symmetry constraint can enhance the quality of foreground object extraction. In our method, a symmetry foreground map is used to represent the symmetry structure of the image, which includes the symmetry matching magnitude and the foreground location prior. Then, the symmetry constraint model is built by introducing this symmetry structure into the graph-based segmentation function. Finally, the segmentation result is obtained via graph cuts. Our method encourages objects with symmetric parts to be consistently extracted. Moreover, our symmetry constraint model is applicable to weak symmetric objects under the part-based framework. Quantitative and qualitative experimental results on benchmark datasets demonstrate the advantages of our approach in extracting the foreground. Our method also shows improved results in segmenting objects with weak, complex symmetry properties.

  2. Magnetotail dynamics under isobaric constraints

    NASA Technical Reports Server (NTRS)

    Birn, Joachim; Schindler, Karl; Janicke, Lutz; Hesse, Michael

    1994-01-01

    Using linear theory and nonlinear MHD simulations, we investigate the resistive and ideal MHD stability of two-dimensional plasma configurations under the isobaric constraint dP/dt = 0, which in ideal MHD is equivalent to conserving the pressure function P = P(A), where A denotes the magnetic flux. This constraint is satisfied for incompressible modes, such as Alfven waves, and for systems undergoing energy losses. The linear stability analysis leads to a Schroedinger equation, which can be investigated by standard quantum mechanics procedures. We present an application to a typical stretched magnetotail configuration. For a one-dimensional sheet equilibrium characteristic properties of tearing instability are rediscovered. However, the maximum growth rate scales with the 1/7 power of the resistivity, which implies much faster growth than for the standard tearing mode (assuming that the resistivity is small). The same basic eigen-mode is found also for weakly two-dimensional equilibria, even in the ideal MHD limit. In this case the growth rate scales with the 1/4 power of the normal magnetic field. The results of the linear stability analysis are confirmed qualitatively by nonlinear dynamic MHD simulations. These results suggest the interesting possibility that substorm onset, or the thinning in the late growth phase, is caused by the release of a thermodynamic constraint without the (immediate) necessity of releasing the ideal MHD constraint. In the nonlinear regime the resistive and ideal developments differ in that the ideal mode does not lead to neutral line formation without the further release of the ideal MHD constraint; instead a thin current sheet forms. The isobaric constraint is critically discussed. Under perhaps more realistic adiabatic conditions the ideal mode appears to be stable but could be driven by external perturbations and thus generate the thin current sheet in the late growth phase, before a nonideal instability sets in.

  3. Evolutionary Constraints to Viroid Evolution

    PubMed Central

    Elena, Santiago F.; Gómez, Gustavo; Daròs, José-Antonio

    2009-01-01

    We suggest that viroids are trapped into adaptive peaks as the result of adaptive constraints. The first one is imposed by the necessity to fold into packed structures to escape from RNA silencing. This creates antagonistic epistases, which make future adaptive trajectories contingent upon the first mutation and slow down the rate of adaptation. This second constraint can only be surpassed by increasing genetic redundancy or by recombination. Eigen’s paradox imposes a limit to the increase in genome complexity in the absence of mechanisms reducing mutation rate. Therefore, recombination appears as the only possible route to evolutionary innovation in viroids. PMID:21994548

  4. The constraint model of attrition

    SciTech Connect

    Hartley, D.S. III.

    1989-01-01

    Helmbold demonstrated a relationship between a ratio containing initial force sizes and casualties, herein called the Helmbold ratio, and the initial force ratio in a large number of historical battles. This paper examines some of the complexity of the Helmbold ratio using analytical and simulation techniques and demonstrates that a constraint model of attrition captures some aspects of historical data. The effect that the constraint model would have on warfare modeling is uncertain. However, some speculation has been attempted concerning its use in large scale simulations. 9 refs., 7 figs., 2 tabs.

  5. Greenstone belt tectonics: Thermal constraints

    NASA Technical Reports Server (NTRS)

    Bickle, M. J.; Nisbet, E. G.

    1986-01-01

    Archaean rocks provide a record of the early stages of planetary evolution. The interpretation is frustrated by the probable unrepresentative nature of the preserved crust and by the well known ambiguities of tectonic geological synthesis. Broad constraints can be placed on the tectonic processes in the early Earth from global scale modeling of thermal and chemical evolution of the Earth and its hydrosphere and atmosphere. The Archean record is the main test of such models. Available general model constraints are outlined based on the global tectonic setting within which Archaean crust evolved and on the direct evidence the Archaean record provides, particularly the thermal state of the early Earth.

  6. How Structural and Physicochemical Determinants Shape Sequence Constraints in a Functional Enzyme

    PubMed Central

    Abriata, Luciano A.; Palzkill, Timothy; Dal Peraro, Matteo

    2015-01-01

    The need for interfacing structural biology and biophysics to molecular evolution is being increasingly recognized. One part of the big problem is to understand how physics and chemistry shape the sequence space available to functional proteins, while satisfying the needs of biology. Here we present a quantitative, structure-based analysis of a high-resolution map describing the tolerance to all substitutions in all positions of a functional enzyme, namely a TEM lactamase previously studied through deep sequencing of mutants growing in competition experiments with selection against ampicillin. Substitutions are rarely observed within 7 Å of the active site, a stringency that is relaxed slowly and extends up to 15–20 Å, with buried residues being especially sensitive. Substitution patterns in over one third of the residues can be quantitatively modeled by monotonic dependencies on amino acid descriptors and predictions of changes in folding stability. Amino acid volume and steric hindrance shape constraints on the protein core; hydrophobicity and solubility shape constraints on hydrophobic clusters underneath the surface, and on salt bridges and polar networks at the protein surface together with charge and hydrogen bonding capacity. Amino acid solubility, flexibility and conformational descriptors also provide additional constraints at many locations. These findings provide fundamental insights into the chemistry underlying protein evolution and design, by quantitating links between sequence and different protein traits, illuminating subtle and unexpected sequence-trait relationships and pinpointing what traits are sacrificed upon gain-of-function mutation. PMID:25706742

  7. Contextual Constraints on Adolescents' Leisure.

    ERIC Educational Resources Information Center

    Silbereisen, Rainer K.

    2003-01-01

    Interlinks crucial cultural themes emerging from preceding chapters, highlighting the contextual constraints in adolescents' use of free time. Draws parallels across the nations discussed on issues related to how school molds leisure time, the balance of passive versus active leisure, timing of leisure pursuits, and the cumulative effect of…

  8. Perceptual Constraints in Phonotactic Learning

    ERIC Educational Resources Information Center

    Endress, Ansgar D.; Mehler, Jacques

    2010-01-01

    Structural regularities in language have often been attributed to symbolic or statistical general purpose computations, whereas perceptual factors influencing such generalizations have received less interest. Here, we use phonotactic-like constraints as a case study to ask whether the structural properties of specific perceptual and memory…

  9. Constraints on galaxy formation theories

    NASA Technical Reports Server (NTRS)

    Szalay, A. S.

    1986-01-01

    The present theories of galaxy formation are reviewed. The relation between peculiar velocities, temperature fluctuations of the microwave background and the correlation function of galaxies point to the possibility that galaxies do not form uniformly everywhere. The velocity data provide strong constraints on the theories even in the case when light does not follow mass of the universe.

  10. Propagating orientation constraints for the Hubble Space Telescope

    NASA Technical Reports Server (NTRS)

    Bose, Ashim; Gerb, Andy

    1994-01-01

    An observing program on the Hubble Space Telescope (HST) is described in terms of exposures that are obtained by one or more of the instruments onboard the HST. Many requested exposures might specify orientation requirements and accompanying ranges. Orientation refers to the amount of roll (in degrees) about the line of sight. The range give the permissible tolerance (also in degrees). These requirements may be (1) absolute (in relation to the celestial coordinate system), (2) relative to the nominal roll angle for HST during that exposure, or (3) relative (in relation to other exposures in the observing program). The TRANSformation expert system converts proposals for astronomical observations with HST into detailed observing plans. Part of the conversion involves grouping exposures into higher level structures based on exposure characteristics. Exposures constrained to be at different orientations cannot be grouped together. Because relative orientation requirements cause implicit constraints, orientation constraints have to be propagated. TRANS must also identify any inconsistencies that may exist so they can be corrected. We have designed and implemented an orientation constraint propagator as part of TRANS. The propagator is based on an informal algebra that facilitates the setting up and propagation of the orientation constraints. The constraint propagator generates constraints between directly related exposures, and propagates derived constraints between exposures that are related indirectly. It provides facilities for path-consistency checking, identification of unsatisfiable constraints, and querying of orientation relationships. The system has been successfully operational as part of TRANS for over seven months. The solution has particular significance to space applications in which satellite/telescope pointing and attitude are constrained and relationships exist between multiple configurations.

  11. Constraints on elastic parameters and implications for lithology on VTI media

    SciTech Connect

    Berge, P.A.

    1995-06-02

    Energy considerations provide constraints on elastic stiffnesses in media exhibiting transverse isotropy with a vertical axis of symmetry. If the anisotropy is due to thin layers, additional constraints hold. The constraints can be used to provide insight into the mechanisms causing the anisotropy, which in turn gives information about the lithology. These ideas are illustrated by some examples of anisotropic sedimentary rocks and sediments from the literature.

  12. Expanding Metabolic Engineering Algorithms Using Feasible Space and Shadow Price Constraint Modules

    PubMed Central

    Tervo, Christopher J.; Reed, Jennifer L.

    2014-01-01

    While numerous computational methods have been developed that use genome-scale models to propose mutants for the purpose of metabolic engineering, they generally compare mutants based on a single criteria (e.g., production rate at a mutant’s maximum growth rate). As such, these approaches remain limited in their ability to include multiple complex engineering constraints. To address this shortcoming, we have developed feasible space and shadow price constraint (FaceCon and ShadowCon) modules that can be added to existing mixed integer linear adaptive evolution metabolic engineering algorithms, such as OptKnock and OptORF. These modules allow strain designs to be identified amongst a set of multiple metabolic engineering algorithm solutions that are capable of high chemical production while also satisfying additional design criteria. We describe the various module implementations and their potential applications to the field of metabolic engineering. We then incorporated these modules into the OptORF metabolic engineering algorithm. Using an Escherichia coli genome-scale model (iJO1366), we generated different strain designs for the anaerobic production of ethanol from glucose, thus demonstrating the tractability and potential utility of these modules in metabolic engineering algorithms. PMID:25478320

  13. The Optimization of Multivariate Generalizability Studies with Budget Constraints.

    ERIC Educational Resources Information Center

    Marcoulides, George A.; Goldstein, Zvi

    1992-01-01

    A method is presented for determining the optimal number of conditions to use in multivariate-multifacet generalizability designs when resource constraints are imposed. A decision maker can determine the number of observations needed to obtain the largest possible generalizability coefficient. The procedure easily applies to the univariate case.…

  14. Solving Constraint-Satisfaction Problems In Prolog Language

    NASA Technical Reports Server (NTRS)

    Nachtsheim, Philip R.

    1991-01-01

    Technique for solution of constraint-satisfaction problems uses definite-clause grammars of Prolog computer language. Exploits fact that grammar-rule notation viewed as "state-change notation". Facilitates development of dynamic representation performing informed as well as blind searches. Applicable to design, scheduling, and planning problems.

  15. The Role of Island Constraints in Second Language Sentence Processing

    ERIC Educational Resources Information Center

    Kim, Eunah; Baek, Soondo; Tremblay, Annie

    2015-01-01

    This study investigates whether adult second language learners' online processing of "wh"-dependencies is constrained by island constraints on movement. Proficiency-matched Spanish and Korean learners of English completed a grammaticality judgment task and a stop-making-sense task designed to examine their knowledge of the relative…

  16. The Efficacy of Multidimensional Constraint Keys in Database Query Performance

    ERIC Educational Resources Information Center

    Cardwell, Leslie K.

    2012-01-01

    This work is intended to introduce a database design method to resolve the two-dimensional complexities inherent in the relational data model and its resulting performance challenges through abstract multidimensional constructs. A multidimensional constraint is derived and utilized to implement an indexed Multidimensional Key (MK) to abstract a…

  17. Perspectives on Additive Manufacturing

    NASA Astrophysics Data System (ADS)

    Bourell, David L.

    2016-07-01

    Additive manufacturing (AM) has skyrocketed in visibility commercially and in the public sector. This article describes the development of this field from early layered manufacturing approaches of photosculpture, topography, and material deposition. Certain precursors to modern AM processes are also briefly described. The growth of the field over the last 30 years is presented. Included is the standard delineation of AM technologies into seven broad categories. The economics of AM part generation is considered, and the impacts of the economics on application sectors are described. On the basis of current trends, the future outlook will include a convergence of AM fabricators, mass-produced AM fabricators, enabling of topology optimization designs, and specialization in the AM legal arena. Long-term developments with huge impact are organ printing and volume-based printing.

  18. Sarks as additional fermions

    NASA Astrophysics Data System (ADS)

    Agrawal, Jyoti; Frampton, Paul H.; Jack Ng, Y.; Nishino, Hitoshi; Yasuda, Osamu

    1991-03-01

    An extension of the standard model is proposed. The gauge group is SU(2) X ⊗ SU(3) C ⊗ SU(2) S ⊗ U(1) Q, where all gauge symmetries are unbroken. The colour and electric charge are combined with SU(2) S which becomes strongly coupled at approximately 500 GeV and binds preons to form fermionic and vector bound states. The usual quarks and leptons are singlets under SU(2) X but additional fermions, called sarks. transform under it and the electroweak group. The present model explains why no more than three light quark-lepton families can exist. Neutral sark baryons, called narks, are candidates for the cosmological dark matter having the characteristics designed for WIMPS. Further phenomenological implications of sarks are analyzed i including electron-positron annihilation. Z 0 decay, flavor-changing neutral currents. baryon-number non-conservation, sarkonium and the neutron electric dipole moment.

  19. Design sensitivity analysis of rotorcraft airframe structures for vibration reduction

    NASA Technical Reports Server (NTRS)

    Murthy, T. Sreekanta

    1987-01-01

    Optimization of rotorcraft structures for vibration reduction was studied. The objective of this study is to develop practical computational procedures for structural optimization of airframes subject to steady-state vibration response constraints. One of the key elements of any such computational procedure is design sensitivity analysis. A method for design sensitivity analysis of airframes under vibration response constraints is presented. The mathematical formulation of the method and its implementation as a new solution sequence in MSC/NASTRAN are described. The results of the application of the method to a simple finite element stick model of the AH-1G helicopter airframe are presented and discussed. Selection of design variables that are most likely to bring about changes in the response at specified locations in the airframe is based on consideration of forced response strain energy. Sensitivity coefficients are determined for the selected design variable set. Constraints on the natural frequencies are also included in addition to the constraints on the steady-state response. Sensitivity coefficients for these constraints are determined. Results of the analysis and insights gained in applying the method to the airframe model are discussed. The general nature of future work to be conducted is described.

  20. Additive manufacturing of optical components

    NASA Astrophysics Data System (ADS)

    Heinrich, Andreas; Rank, Manuel; Maillard, Philippe; Suckow, Anne; Bauckhage, Yannick; Rößler, Patrick; Lang, Johannes; Shariff, Fatin; Pekrul, Sven

    2016-08-01

    The development of additive manufacturing methods has enlarged rapidly in recent years. Thereby, the work mainly focuses on the realization of mechanical components, but the additive manufacturing technology offers a high potential in the field of optics as well. Owing to new design possibilities, completely new solutions are possible. This article briefly reviews and compares the most important additive manufacturing methods for polymer optics. Additionally, it points out the characteristics of additive manufactured polymer optics. Thereby, surface quality is of crucial importance. In order to improve it, appropriate post-processing steps are necessary (e.g. robot polishing or coating), which will be discussed. An essential part of this paper deals with various additive manufactured optical components and their use, especially in optical systems for shape metrology (e.g. borehole sensor, tilt sensor, freeform surface sensor, fisheye lens). The examples should demonstrate the potentials and limitations of optical components produced by additive manufacturing.

  1. Summary of NDE of Additive Manufacturing Efforts in NASA

    NASA Technical Reports Server (NTRS)

    Waller, Jess; Saulsberry, Regor; Parker, Bradford; Hodges, Kenneth; Burke, Eric; Taminger, Karen

    2014-01-01

    (1) General Rationale for Additive Manufacturing (AM): (a) Operate under a 'design-to-constraint' paradigm, make parts too complicated to fabricate otherwise, (b) Reduce weight by 20 percent with monolithic parts, (c) Reduce waste (green manufacturing), (e) Eliminate reliance on Original Equipment Manufacturers for critical spares, and (f) Extend life of in-service parts by innovative repair methods; (2) NASA OSMA NDE of AM State-of-the-Discipline Report; (3) Overview of NASA AM Efforts at Various Centers: (a) Analytical Tools, (b) Ground-Based Fabrication (c) Space-Based Fabrication; and (d) Center Activity Summaries; (4) Overview of NASA NDE data to date on AM parts; and (5) Gap Analysis/Recommendations for NDE of AM.

  2. Cosmic Shear Results from the Deep Lens Survey. II. Full Cosmological Parameter Constraints from Tomography

    NASA Astrophysics Data System (ADS)

    Jee, M. James; Tyson, J. Anthony; Hilbert, Stefan; Schneider, Michael D.; Schmidt, Samuel; Wittman, David

    2016-06-01

    We present a tomographic cosmic shear study from the Deep Lens Survey (DLS), which, providing a limiting magnitude {r}{lim}˜ 27 (5σ ), is designed as a precursor Large Synoptic Survey Telescope (LSST) survey with an emphasis on depth. Using five tomographic redshift bins, we study their auto- and cross-correlations to constrain cosmological parameters. We use a luminosity-dependent nonlinear model to account for the astrophysical systematics originating from intrinsic alignments of galaxy shapes. We find that the cosmological leverage of the DLS is among the highest among existing \\gt 10 deg2 cosmic shear surveys. Combining the DLS tomography with the 9 yr results of the Wilkinson Microwave Anisotropy Probe (WMAP9) gives {{{Ω }}}m={0.293}-0.014+0.012, {σ }8={0.833}-0.018+0.011, {H}0={68.6}-1.2+1.4 {\\text{km s}}-1 {{{Mpc}}}-1, and {{{Ω }}}b=0.0475+/- 0.0012 for ΛCDM, reducing the uncertainties of the WMAP9-only constraints by ˜50%. When we do not assume flatness for ΛCDM, we obtain the curvature constraint {{{Ω }}}k=-{0.010}-0.015+0.013 from the DLS+WMAP9 combination, which, however, is not well constrained when WMAP9 is used alone. The dark energy equation-of-state parameter w is tightly constrained when baryonic acoustic oscillation (BAO) data are added, yielding w=-{1.02}-0.09+0.10 with the DLS+WMAP9+BAO joint probe. The addition of supernova constraints further tightens the parameter to w=-1.03+/- 0.03. Our joint constraints are fully consistent with the final Planck results and also with the predictions of a ΛCDM universe.

  3. Differing nutritional constraints of consumers across ecosystems.

    PubMed

    Lemoine, Nathan P; Giery, Sean T; Burkepile, Deron E

    2014-04-01

    Stoichiometric mismatches between resources and consumers may drive a number of important ecological interactions, such as predation and herbivory. Such mismatches in nitrogen (N) or phosphorus (P) content between resources and consumers have furthered our understanding of consumer behavior and growth patterns in aquatic systems. However, stoichiometric data for multiple consumers from the same community are lacking in terrestrial systems. Here, we present the results of a study designed to characterize nutritional constraints within a terrestrial arthropod community. In order to place our results in a broader context, we compared our data on resource-consumer stoichiometry to those of stream and lake ecosystems. We found that N and P varied among trophic levels, and that high N:P content of herbivores suggests that herbivores might experience strong N-limitation. However, incredibly low P-content of plant foliage leads to potential P-limitation in herbivores that is nearly as strong as potential N-limitation. Moreover, arthropod predators may also be strongly P-limited. In fact, potential nutrient limitation of terrestrial herbivores in our study is similar to nutrient limitation from streams and lakes, suggesting that similar nutritional constraints may be operating across all three study systems. Importantly, our data suggest that consumers in lakes experience a trade-off between N- and P-limitation, while terrestrial consumers experience simultaneous strengthening or weakening of N- and P-limitation. We suggest that P may be overlooked as an important limiting nutrient in terrestrial ecosystems. PMID:24380968

  4. Unitarity constraints on trimaximal mixing

    SciTech Connect

    Kumar, Sanjeev

    2010-07-01

    When the neutrino mass eigenstate {nu}{sub 2} is trimaximally mixed, the mixing matrix is called trimaximal. The middle column of the trimaximal mixing matrix is identical to tribimaximal mixing and the other two columns are subject to unitarity constraints. This corresponds to a mixing matrix with four independent parameters in the most general case. Apart from the two Majorana phases, the mixing matrix has only one free parameter in the CP conserving limit. Trimaximality results in interesting interplay between mixing angles and CP violation. A notion of maximal CP violation naturally emerges here: CP violation is maximal for maximal 2-3 mixing. Similarly, there is a natural constraint on the deviation from maximal 2-3 mixing which takes its maximal value in the CP conserving limit.

  5. Domestication changes innate constraints for birdsong learning.

    PubMed

    Kagawa, Hiroko; Suzuki, Kenta; Takahasi, Miki; Okanoya, Kazuo

    2014-07-01

    Birdsongs are acquired by imitating the sounds produced by conspecifics. Within a species, songs diverge by cultural transmission, but the range of species-specific features is restricted by innate constraints. Bengalese finches (Lonchura striata var. domestica) are a domesticated strain of the wild White-rumped munia (Lonchura striata). The songs of the domesticated strain have more tonal sounds and more variable sequences than those of the wild strain. We compared the features of songs that were produced by normal birds, isolation-reared birds, and cross-fostered birds in both White-rumped munias and Bengalese finches to identify differences in the genetic and environmental factors of their songs. Factor analyses were conducted based on 17 song measurements. We found that isolated songs differed from normal and cross-fostered songs, especially in unstable prosodic features. In addition, there were significant differences in sound property of mean frequency between the two strains regardless of the rearing conditions. Thus, innate constraints that partially determine birdsong phenotypes may be altered through domestication.

  6. Domestication changes innate constraints for birdsong learning.

    PubMed

    Kagawa, Hiroko; Suzuki, Kenta; Takahasi, Miki; Okanoya, Kazuo

    2014-07-01

    Birdsongs are acquired by imitating the sounds produced by conspecifics. Within a species, songs diverge by cultural transmission, but the range of species-specific features is restricted by innate constraints. Bengalese finches (Lonchura striata var. domestica) are a domesticated strain of the wild White-rumped munia (Lonchura striata). The songs of the domesticated strain have more tonal sounds and more variable sequences than those of the wild strain. We compared the features of songs that were produced by normal birds, isolation-reared birds, and cross-fostered birds in both White-rumped munias and Bengalese finches to identify differences in the genetic and environmental factors of their songs. Factor analyses were conducted based on 17 song measurements. We found that isolated songs differed from normal and cross-fostered songs, especially in unstable prosodic features. In addition, there were significant differences in sound property of mean frequency between the two strains regardless of the rearing conditions. Thus, innate constraints that partially determine birdsong phenotypes may be altered through domestication. PMID:24793499

  7. Solar electric geocentric transfer with attitude constraints: Analysis

    NASA Technical Reports Server (NTRS)

    Sackett, L. L.; Malchow, H. L.; Delbaum, T. N.

    1975-01-01

    A time optimal or nearly time optimal trajectory program was developed for solar electric geocentric transfer with or without attitude constraints and with an optional initial high thrust stage. The method of averaging reduces computation time. A nonsingular set of orbital elements is used. The constraints, which are those of one of the SERT-C designs, introduce complexities into the analysis and the solution yields possible discontinuous changes in thrust direction. The power degradation due to VanAllen radiation is modeled analytically. A wide range of solar cell characteristics is assumed. Effects such as oblateness and shadowing are included. The analysis and the results of many example runs are included.

  8. Parametrized modified gravity constraints after Planck

    NASA Astrophysics Data System (ADS)

    Hu, Bin; Liguori, Michele; Bartolo, Nicola; Matarrese, Sabino

    2013-12-01

    We constrain f(R) and chameleon-type modified gravity in the framework of the Berstchinger-Zukin parametrization using the recently released Planck data, including both the cosmic mircowave background radiation (CMB) temperature power spectrum and the lensing potential power spectrum. Some other external data sets are included, such as baryon acoustic oscillation (BAO) measurements from the 6dFGS, SDSS DR7 and BOSS DR9 surveys; Hubble Space Telescope (HST) H0 measurements, and supernovae from the Union2.1 compilation. We also use WMAP9 data for a consistency check and comparison. For f(R) gravity, WMAP9 results can only give a quite loose constraint on the modified gravity parameter B0, which is related to the present value of the Compton wavelength of the extra scalar degree of freedom, B0<3.37 at 95% C.L. We demonstrate that this constraint mainly comes from the late integrated Sachs-Wolfe effect. With only Planck CMB temperature power-spectrum data, we can improve the WMAP9 result by a factor 3.7 (B0<0.91 at 95% C.L.). If the Planck lensing potential power-spectrum data are also taken into account, the constraint can be further strengthened by a factor 5.1 (B0<0.18 at 95% C.L.). This major improvement mainly comes from the small-scale lensing signal. Furthermore, BAO, HST and supernovae data could slightly improve the B0 bound (B0<0.12 at 95% C.L.). For the chameleon-type model, we find that the data set that we used cannot constrain the Compton wavelength B0 or the potential index s of the chameleon field, but it can give a tight constraint on the parameter β1=1.043-0.104+0.163 at 95% C.L. (β1=1 in general relativity), which accounts for the nonminimal coupling between the chameleon field and the matter component. In addition, we find that both modified gravity models we consider favor a relatively higher Hubble parameter than the concordance ΛCDM model in general relativity.

  9. Constraints of Implementing Free Secondary Education in Mandera West Sub-County, Mandera County, Kenya

    ERIC Educational Resources Information Center

    Adan, Mohammed Abdi; Orodho, John Aluko

    2015-01-01

    This study sought to find out the constraints of implementing free secondary education (FSE) in secondary schools in Mandera West Sub-County, Mandera County, Kenya. The study is based on the theory of constraints as the researcher examines the factors constraining the achievement of FSE objectives. The study used the survey design. The main…

  10. Managing Restaurant Tables using Constraints

    NASA Astrophysics Data System (ADS)

    Vidotto, Alfio; Brown, Kenneth N.; Beck, J. Christopher

    Restaurant table management can have significant impact on both profitability and the customer experience. The core of the issue is a complex dynamic combinatorial problem. We show how to model the problem as constraint satisfaction, with extensions which generate flexible seating plans and which maintain stability when changes occur. We describe an implemented system which provides advice to users in real time. The system is currently being evaluated in a restaurant environment.

  11. Macroscopic constraints on string unification

    SciTech Connect

    Taylor, T.R.

    1989-03-01

    The comparison of sting theory with experiment requires a huge extrapolation from the microscopic distances, of order of the Planck length, up to the macroscopic laboratory distances. The quantum effects give rise to large corrections to the macroscopic predictions of sting unification. I discus the model-independent constraints on the gravitational sector of string theory due to the inevitable existence of universal Fradkin-Tseytlin dilatons. 9 refs.

  12. Aeroelastic Tailoring of Transport Wings Including Transonic Flutter Constraints

    NASA Technical Reports Server (NTRS)

    Stanford, Bret K.; Wieseman, Carol D.; Jutte, Christine V.

    2015-01-01

    Several minimum-mass optimization problems are solved to evaluate the effectiveness of a variety of novel tailoring schemes for subsonic transport wings. Aeroelastic stress and panel buckling constraints are imposed across several trimmed static maneuver loads, in addition to a transonic flutter margin constraint, captured with aerodynamic influence coefficient-based tools. Tailoring with metallic thickness variations, functionally graded materials, balanced or unbalanced composite laminates, curvilinear tow steering, and distributed trailing edge control effectors are all found to provide reductions in structural wing mass with varying degrees of success. The question as to whether this wing mass reduction will offset the increased manufacturing cost is left unresolved for each case.

  13. Observational Constraints on Planet Nine: Cassini Range Observations

    NASA Astrophysics Data System (ADS)

    Holman, Matthew J.; Payne, Matthew J.

    2016-10-01

    We examine the tidal perturbations induced by a possible additional, distant planet in the solar system on the distance between the Earth and the Cassini spacecraft. We find that measured range residuals alone can significantly constrain the sky position, distance, and mass of the perturbing planet to sections of the sky essentially orthogonal to the orbit of Saturn. When we combine these constraints from tidal perturbations with the dynamical constraints from Batygin & Brown and Brown & Batygin, we further constrain the allowed location of the perturbing planet to a region of the sky approximately centered on (R.A., decl.) = (40°, ‑15°) and extending ∼20° in all directions.

  14. Mechanical contact by constraints and split-based preconditioning

    SciTech Connect

    Dmitry Karpeyev; Derek Gaston; Jason Hales; Steven Novascone

    2014-03-01

    An accurate implementation of glued mechanical contact was developed in MOOSE based on its Constraint system. This approach results in a superior convergence of elastic structure problems, in particular in BISON. Adaptation of this technique to frictionless and frictional contact models is under way. Additionally, the improved convergence of elastic problems results from the application of the split-based preconditioners to constraint-based systems. This yields a substantial increase in the robustness of elastic solvers when the number of nodes in contact is increased and/or the mesh is refined.

  15. An analytical study for the design of advanced rotor airfoils

    NASA Technical Reports Server (NTRS)

    Kemp, L. D.

    1973-01-01

    A theoretical study has been conducted to design and evaluate two airfoils for helicopter rotors. The best basic shape, designed with a transonic hodograph design method, was modified to meet subsonic criteria. One airfoil had an additional constraint for low pitching-moment at the transonic design point. Airfoil characteristics were predicted. Results of a comparative analysis of helicopter performance indicate that the new airfoils will produce reduced rotor power requirements compared to the NACA 0012. The hodograph design method, written in CDC Algol, is listed and described.

  16. Updating neutrino magnetic moment constraints

    NASA Astrophysics Data System (ADS)

    Cañas, B. C.; Miranda, O. G.; Parada, A.; Tórtola, M.; Valle, J. W. F.

    2016-02-01

    In this paper we provide an updated analysis of the neutrino magnetic moments (NMMs), discussing both the constraints on the magnitudes of the three transition moments Λi and the role of the CP violating phases present both in the mixing matrix and in the NMM matrix. The scattering of solar neutrinos off electrons in Borexino provides the most stringent restrictions, due to its robust statistics and the low energies observed, below 1 MeV. Our new limit on the effective neutrino magnetic moment which follows from the most recent Borexino data is 3.1 ×10-11μB at 90% C.L. This corresponds to the individual transition magnetic moment constraints: |Λ1 | ≤ 5.6 ×10-11μB, |Λ2 | ≤ 4.0 ×10-11μB, and |Λ3 | ≤ 3.1 ×10-11μB (90% C.L.), irrespective of any complex phase. Indeed, the incoherent admixture of neutrino mass eigenstates present in the solar flux makes Borexino insensitive to the Majorana phases present in the NMM matrix. For this reason we also provide a global analysis including the case of reactor and accelerator neutrino sources, presenting the resulting constraints for different values of the relevant CP phases. Improved reactor and accelerator neutrino experiments will be needed in order to underpin the full profile of the neutrino electromagnetic properties.

  17. Infrared Constraint on Ultraviolet Theories

    SciTech Connect

    Tsai, Yuhsin

    2012-08-01

    While our current paradigm of particle physics, the Standard Model (SM), has been extremely successful at explaining experiments, it is theoretically incomplete and must be embedded into a larger framework. In this thesis, we review the main motivations for theories beyond the SM (BSM) and the ways such theories can be constrained using low energy physics. The hierarchy problem, neutrino mass and the existence of dark matter (DM) are the main reasons why the SM is incomplete . Two of the most plausible theories that may solve the hierarchy problem are the Randall-Sundrum (RS) models and supersymmetry (SUSY). RS models usually suffer from strong flavor constraints, while SUSY models produce extra degrees of freedom that need to be hidden from current experiments. To show the importance of infrared (IR) physics constraints, we discuss the flavor bounds on the anarchic RS model in both the lepton and quark sectors. For SUSY models, we discuss the difficulties in obtaining a phenomenologically allowed gaugino mass, its relation to R-symmetry breaking, and how to build a model that avoids this problem. For the neutrino mass problem, we discuss the idea of generating small neutrino masses using compositeness. By requiring successful leptogenesis and the existence of warm dark matter (WDM), we can set various constraints on the hidden composite sector. Finally, to give an example of model independent bounds from collider experiments, we show how to constrain the DM–SM particle interactions using collider results with an effective coupling description.

  18. Isocurvature constraints on portal couplings

    NASA Astrophysics Data System (ADS)

    Kainulainen, Kimmo; Nurmi, Sami; Tenkanen, Tommi; Tuominen, Kimmo; Vaskonen, Ville

    2016-06-01

    We consider portal models which are ultraweakly coupled with the Standard Model, and confront them with observational constraints on dark matter abundance and isocurvature perturbations. We assume the hidden sector to contain a real singlet scalar s and a sterile neutrino ψ coupled to s via a pseudoscalar Yukawa term. During inflation, a primordial condensate consisting of the singlet scalar s is generated, and its contribution to the isocurvature perturbations is imprinted onto the dark matter abundance. We compute the total dark matter abundance including the contributions from condensate decay and nonthermal production from the Standard Model sector. We then use the Planck limit on isocurvature perturbations to derive a novel constraint connecting dark matter mass and the singlet self coupling with the scale of inflation: mDM/GeV lesssim 0.2λs3/8 (H*/1011 GeV)‑3/2. This constraint is relevant in most portal models ultraweakly coupled with the Standard Model and containing light singlet scalar fields.

  19. Steric constraints as folding coadjuvant

    NASA Astrophysics Data System (ADS)

    Tarragó, M. E.; Rocha, Luiz F.; Dasilva, R. A.; Caliri, A.

    2003-03-01

    Through the analyses of the Miyazawa-Jernigan matrix it has been shown that the hydrophobic effect generates the dominant driving force for protein folding. By using both lattice and off-lattice models, it is shown that hydrophobic-type potentials are indeed efficient in inducing the chain through nativelike configurations, but they fail to provide sufficient stability so as to keep the chain in the native state. However, through comparative Monte Carlo simulations, it is shown that hydrophobic potentials and steric constraints are two basic ingredients for the folding process. Specifically, it is shown that suitable pairwise steric constraints introduce strong changes on the configurational activity, whose main consequence is a huge increase in the overall stability condition of the native state; detailed analysis of the effects of steric constraints on the heat capacity and configurational activity are provided. The present results support the view that the folding problem of globular proteins can be approached as a process in which the mechanism to reach the native conformation and the requirements for the globule stability are uncoupled.

  20. Constraint programming based biomarker optimization.

    PubMed

    Zhou, Manli; Luo, Youxi; Sun, Guoquan; Mai, Guoqin; Zhou, Fengfeng

    2015-01-01

    Efficient and intuitive characterization of biological big data is becoming a major challenge for modern bio-OMIC based scientists. Interactive visualization and exploration of big data is proven to be one of the successful solutions. Most of the existing feature selection algorithms do not allow the interactive inputs from users in the optimizing process of feature selection. This study investigates this question as fixing a few user-input features in the finally selected feature subset and formulates these user-input features as constraints for a programming model. The proposed algorithm, fsCoP (feature selection based on constrained programming), performs well similar to or much better than the existing feature selection algorithms, even with the constraints from both literature and the existing algorithms. An fsCoP biomarker may be intriguing for further wet lab validation, since it satisfies both the classification optimization function and the biomedical knowledge. fsCoP may also be used for the interactive exploration of bio-OMIC big data by interactively adding user-defined constraints for modeling.