Science.gov

Sample records for additional design constraints

  1. PID Controller Design Based on Global Optimization Technique with Additional Constraints

    NASA Astrophysics Data System (ADS)

    Ozana, Stepan; Docekal, Tomas

    2016-05-01

    This paper deals with design of PID controller with the use of methods of global optimization implemented in Matlab environment and Optimization Toolbox. It is based on minimization of a chosen integral criterion with respect to additional requirements on control quality such as overshoot, phase margin and limits for manipulated value. The objective function also respects user-defined weigh coefficients for its particular terms for a different penalization of individual requirements that often clash each other such as for example overshoot and phase margin. The described solution is designated for continuous linear time-invariant static systems up to 4th order and thus efficient for the most of real control processes in practice.

  2. The Probabilistic Admissible Region with Additional Constraints

    NASA Astrophysics Data System (ADS)

    Roscoe, C.; Hussein, I.; Wilkins, M.; Schumacher, P.

    The admissible region, in the space surveillance field, is defined as the set of physically acceptable orbits (e.g., orbits with negative energies) consistent with one or more observations of a space object. Given additional constraints on orbital semimajor axis, eccentricity, etc., the admissible region can be constrained, resulting in the constrained admissible region (CAR). Based on known statistics of the measurement process, one can replace hard constraints with a probabilistic representation of the admissible region. This results in the probabilistic admissible region (PAR), which can be used for orbit initiation in Bayesian tracking and prioritization of tracks in a multiple hypothesis tracking framework. The PAR concept was introduced by the authors at the 2014 AMOS conference. In that paper, a Monte Carlo approach was used to show how to construct the PAR in the range/range-rate space based on known statistics of the measurement, semimajor axis, and eccentricity. An expectation-maximization algorithm was proposed to convert the particle cloud into a Gaussian Mixture Model (GMM) representation of the PAR. This GMM can be used to initialize a Bayesian filter. The PAR was found to be significantly non-uniform, invalidating an assumption frequently made in CAR-based filtering approaches. Using the GMM or particle cloud representations of the PAR, orbits can be prioritized for propagation in a multiple hypothesis tracking (MHT) framework. In this paper, the authors focus on expanding the PAR methodology to allow additional constraints, such as a constraint on perigee altitude, to be modeled in the PAR. This requires re-expressing the joint probability density function for the attributable vector as well as the (constrained) orbital parameters and range and range-rate. The final PAR is derived by accounting for any interdependencies between the parameters. Noting that the concepts presented are general and can be applied to any measurement scenario, the idea

  3. 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.

  4. Improvement of MEM-deconvolution by an additional constraint

    NASA Astrophysics Data System (ADS)

    Reiter, J.; Pfleiderer, J.

    1986-09-01

    An attempt is made to improve existing versions of the maximum entropy method (MEM) and their understanding. Additional constraints are discussed, especially the T-statistic which can significantly reduce the correlation between residuals and model. An implementation of the T constraint into MEM requires a new numerical algorithm, which is made to work most efficiently on modern vector-processing computers. The entropy functional is derived from simple mathematical assumptions. The new MEM version is tested with radio data of NGC 6946 and optical data from M 87.

  5. Exploiting Constraints in Design Synthesis

    DTIC Science & Technology

    1987-04-01

    policy for a state. Herbert Simon , The Science of Design 1.1 Overview Robot planning, genetic synthesis, chemical synthesis, circuit design, and...Sanders Peirce (1839-1914) [36] used "abduction" to mean the "creative formulation of statistical hypotheses" (Encyclopedia of Philosophy, page 4-176... theory be part of the design. In short, there is a certain threshold of detail that is agreed upon by the designer and implementor as being primitively

  6. Optimal design of structures with buckling constraints.

    NASA Technical Reports Server (NTRS)

    Kiusalaas, J.

    1973-01-01

    The paper presents an iterative, finite element method for minimum weight design of structures with respect to buckling constraints. The redesign equation is derived from the optimality criterion, as opposed to a numerical search procedure, and can handle problems that are characterized by the existence of two fundamental buckling modes at the optimal design. Application of the method is illustrated by beam and orthogonal frame design problems.

  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. Material constraints on high-speed design

    NASA Astrophysics Data System (ADS)

    Bucur, Diana; Militaru, Nicolae

    2015-02-01

    Current high-speed circuit designs with signal rates up to 100Gbps and above are implying constraints for dielectric and conductive materials and their dependence of frequency, for component elements and for production processes. The purpose of this paper is to highlight through various simulation results the frequency dependence of specific parameters like insertion and return loss, eye diagrams, group delay that are part of signal integrity analyses type. In low-power environment designs become more complex as the operation frequency increases. The need for new materials with spatial uniformity for dielectric constant is a need for higher data rates circuits. The fiber weave effect (FWE) will be analyzed through the eye diagram results for various dielectric materials in a differential signaling scheme given the fact that the FWE is a phenomenon that affects randomly the performance of the circuit on balanced/differential transmission lines which are typically characterized through the above mentioned approaches. Crosstalk between traces is also of concern due to propagated signals that have tight rise and fall times or due to high density of the boards. Criteria should be considered to achieve maximum performance of the designed system requiring critical electronic properties.

  10. Designing a Constraint Based Parser for Sanskrit

    NASA Astrophysics Data System (ADS)

    Kulkarni, Amba; Pokar, Sheetal; Shukl, Devanand

    Verbal understanding (śā bdabodha) of any utterance requires the knowledge of how words in that utterance are related to each other. Such knowledge is usually available in the form of cognition of grammatical relations. Generative grammars describe how a language codes these relations. Thus the knowledge of what information various grammatical relations convey is available from the generation point of view and not the analysis point of view. In order to develop a parser based on any grammar one should then know precisely the semantic content of the grammatical relations expressed in a language string, the clues for extracting these relations and finally whether these relations are expressed explicitly or implicitly. Based on the design principles that emerge from this knowledge, we model the parser as finding a directed Tree, given a graph with nodes representing the words and edges representing the possible relations between them. Further, we also use the Mīmā ṃsā constraint of ākā ṅkṣā (expectancy) to rule out non-solutions and sannidhi (proximity) to prioritize the solutions. We have implemented a parser based on these principles and its performance was found to be satisfactory giving us a confidence to extend its functionality to handle the complex sentences.

  11. Additional constraints on circumstellar disks in the Trapezium Cluster

    NASA Technical Reports Server (NTRS)

    Stauffer, John R.; Prosser, Charles F.; Hartmann, Lee; Mccaughrean, Mark J.

    1994-01-01

    We discuss new constraints on the population of compact ionized sources in the Trapezium Cluster thought to arise from the ionization by the central OB stars of circumstellar disks around low-mass pre-main sequence stars. We present new HST Planetary Camera observations of two of these candidate disk sources, resolving extended nebulosity around them. One source shows a small-scale (greater than 100 AU) bow-shock structure, previously seen on larger scales by O'Dell et al. We show that the circumstellar disk model is the most likely one for the majority of sources, although it remains plausible that some of the larger objects could be equilibrium globules. We combine the most complete censuses of compact radio sources and stars in the core region to derive the fraction of the stellar population that may be associated with a circumstellar disk. Our estimate of 25-75 percent is comparable to that found for PMS stars in the Taurus-Auriga dark clouds, indicating that the dense cluster environment of the Trapezium has not drastically reduced the frequency of disks seen around pre-main sequence stars.

  12. 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.

  13. 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.

  14. 77 FR 48609 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-14

    ... Office of Foreign Assets Control Additional Designations, Foreign Narcotics Kingpin Designation Act... Narcotics Kingpin Designation Act (``Kingpin Act''). DATES: The designation by the Director of OFAC of the... of significant foreign narcotics traffickers and their organizations on a worldwide basis....

  15. 78 FR 59766 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-27

    ... Office of Foreign Assets Control Additional Designations, Foreign Narcotics Kingpin Designation Act... Narcotics Kingpin Designation Act (``Kingpin Act''). DATES: The designation by the Director of OFAC of the... establishes a program targeting the activities of significant foreign narcotics ] traffickers and...

  16. Optimizing Measurement Designs with Budget Constraints: The Variable Cost Case.

    ERIC Educational Resources Information Center

    Marcoulides, George A.

    1997-01-01

    Presents a procedure for determining the optimal number of conditions to use in multifaceted measurement designs when resource constraints are imposed. The procedure is illustrated for the case in which the costs per condition vary within the same facet. (Author)

  17. 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. ...

  18. 77 FR 22846 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-17

    ... 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 Designation... significant foreign narcotics traffickers and their organizations on a worldwide basis. It provides...

  19. 75 FR 65554 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-25

    ... Office of Foreign Assets Control Additional Designations, Foreign Narcotics Kingpin Designation Act... interests in property has been blocked pursuant to the Foreign Narcotics Kingpin Designation Act (``Kingpin..., 1999. The Kingpin Act establishes a program targeting the activities of significant foreign...

  20. 77 FR 36041 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-15

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

  1. 78 FR 29814 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-21

    ... 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 Designation... significant foreign narcotics traffickers and their organizations on a worldwide basis. It provides...

  2. 78 FR 3083 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-15

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

  3. 78 FR 53007 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-27

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

  4. 77 FR 56271 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-12

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

  5. 76 FR 56875 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-14

    ... Office of Foreign Assets Control Additional Designations, Foreign Narcotics Kingpin Designation Act... interests in property have been blocked pursuant to the Foreign Narcotics Kingpin Designation Act (``Kingpin... significant foreign narcotics traffickers and their organizations on a worldwide basis. It provides...

  6. 76 FR 25407 - 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... property and interests in property are blocked pursuant to the Foreign Narcotics Kingpin Designation Act... targeting the activities of significant foreign narcotics ] traffickers and their organizations on...

  7. 76 FR 5857 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-02

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

  8. 77 FR 28670 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-15

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

  9. 77 FR 63418 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-16

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

  10. 78 FR 28289 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-14

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

  11. 77 FR 2347 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-17

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

  12. 76 FR 5858 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-02

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

  13. 78 FR 13760 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-28

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

  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. 78 FR 9997 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-12

    ... Office of Foreign Assets Control Additional Designations, Foreign Narcotics Kingpin Designation Act... Narcotics Kingpin Designation Act (``Kingpin Act'') (21 U.S.C. 1901-1908, 8 U.S.C. 1182). In addition, OFAC... establishes a program targeting the activities of significant foreign narcotics traffickers and...

  17. Transient design of landfill liquid addition systems.

    PubMed

    Jain, Pradeep; Townsend, Timothy G; Tolaymat, Thabet M

    2014-09-01

    This study presents the development of design charts that can be used to estimate lateral and vertical spacing of liquids addition devices (e.g., vertical well, horizontal trenches) and the operating duration needed for transient operating conditions (conditions until steady-state operating conditions are achieved). These design charts should be used in conjunction with steady-state design charts published earlier by Jain et al. (2010a, 2010b). The data suggest that the liquids addition system operating time can be significantly reduced by utilizing moderately closer spacing between liquids addition devices than the spacing needed for steady-state conditions. These design charts can be used by designers to readily estimate achievable flow rate and lateral and vertical extents of the zone of impact from liquid addition devices, and analyze the sensitivity of various input variables (e.g., hydraulic conductivity, anisotropy, well radius, screen length) to the design. The applicability of the design charts, which are developed based on simulations of a continuously operated system, was also evaluated for the design of a system that would be operated intermittently (e.g., systems only operated during facility operating hours). The design charts somewhat underestimates the flow rate achieved and overestimates the lateral extent of the zone of impact over an operating duration for an intermittently operated system. The associated estimation errors would be smaller than the margin of errors associated with measurement of other key design inputs such as waste properties (e.g., hydraulic conductivity) and wider variation of these properties at a given site due to heterogeneous nature of waste.

  18. 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.

  19. 78 FR 66105 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-04

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

  20. 78 FR 8701 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-06

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

  1. 77 FR 58912 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-24

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

  2. 77 FR 838 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-06

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

  3. 77 FR 69706 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-20

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

  4. 75 FR 64781 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-20

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

  5. 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...

  6. 77 FR 4400 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-27

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

  7. 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...

  8. 77 FR 38140 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-26

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

  9. 78 FR 62946 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-22

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

  10. 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...

  11. 76 FR 10668 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-25

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

  12. An algorithm for optimal structural design with frequency constraints

    NASA Technical Reports Server (NTRS)

    Kiusalaas, J.; Shaw, R. C. J.

    1978-01-01

    The paper presents a finite element method for minimum weight design of structures with lower-bound constraints on the natural frequencies, and upper and lower bounds on the design variables. The design algorithm is essentially an iterative solution of the Kuhn-Tucker optimality criterion. The three most important features of the algorithm are: (1) a small number of design iterations are needed to reach optimal or near-optimal design, (2) structural elements with a wide variety of size-stiffness may be used, the only significant restriction being the exclusion of curved beam and shell elements, and (3) the algorithm will work for multiple as well as single frequency constraints. The design procedure is illustrated with three simple problems.

  13. 75 FR 24773 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-05

    ... Office of Foreign Assets Control Additional Designations, Foreign Narcotics Kingpin Designation Act... and interests in property have been blocked pursuant to the Foreign Narcotics Kingpin Designation Act... narcotics traffickers and their organizations on a worldwide basis. It provides a statutory framework...

  14. 75 FR 44311 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-28

    ... Office of Foreign Assets Control Additional Designations, Foreign Narcotics Kingpin Designation Act... interests in property have been blocked pursuant to the Foreign Narcotics Kingpin Designation Act (``Kingpin... narcotics traffickers and their organizations on a worldwide basis. It provides a statutory framework...

  15. 76 FR 58562 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-21

    ... Office of Foreign Assets Control Additional Designations, Foreign Narcotics Kingpin Designation Act... and interests in property have been blocked pursuant to the Foreign Narcotics Kingpin Designation Act... narcotics traffickers and their organizations on a worldwide basis with the objective of denying...

  16. 76 FR 23644 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-27

    ... Office of Foreign Assets Control Additional Designations, Foreign Narcotics Kingpin Designation Act... and interests in property have been blocked pursuant to the Foreign Narcotics Kingpin Designation Act... narcotics traffickers and their organizations on a worldwide basis. It provides a statutory framework...

  17. 75 FR 20425 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-19

    ... Office of Foreign Assets Control Additional Designations, Foreign Narcotics Kingpin Designation Act... property and interests in property have been blocked pursuant to the Foreign Narcotics Kingpin Designation... narcotics traffickers and their organizations on a worldwide basis. It provides a statutory framework...

  18. 77 FR 6191 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-07

    ... Office of Foreign Assets Control Additional Designations, Foreign Narcotics Kingpin Designation Act... Narcotics Kingpin Designation Act (``Kingpin Act'') (21 U.S.C. 1901-1908, 8 U.S.C. 1182). DATES: The... establishes a program targeting the activities of significant foreign narcotics traffickers and...

  19. 77 FR 14859 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-13

    ... Office of Foreign Assets Control Additional Designations, Foreign Narcotics Kingpin Designation Act... interests in property have been blocked pursuant to the Foreign Narcotics Kingpin Designation Act (``Kingpin... narcotics traffickers and their organizations on a worldwide basis. It provides a statutory framework...

  20. 77 FR 39573 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-03

    ... Office of Foreign Assets Control Additional Designations, Foreign Narcotics Kingpin Designation Act... Narcotics Kingpin Designation Act (``Kingpin Act'') (21 U.S.C. 1901-1908, 8 U.S.C. 1182). OFAC is also.... The Kingpin Act establishes a program targeting the activities of significant foreign...

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

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-27

    ... Office of Foreign Assets Control Additional Designation, Foreign Narcotics Kingpin Designation Act AGENCY... property and interests in property has been blocked pursuant to the Foreign Narcotics Kingpin Designation... significant foreign narcotics traffickers and their organizations on a worldwide basis. It provides...

  2. Optimal filter design subject to output delobe constraints

    NASA Technical Reports Server (NTRS)

    Fortmann, T. E.; Athans, M.

    1972-01-01

    The design of filters for detection and estimation in radar and communications systems is considered, with inequality constraints on the maximum output sidelobe levels. A constrained optimization problem in Hilbert space is formulated, incorporating the sidelobe constraints via a partial ordering of continuous functions. Generalized versions (in Hilbert space) of the Kuhn-Tucker and Duality Theorems allow the reduction of this problem to an unconstrained one in the dual space of regular Borel measures. A convergent algorithm is presented for computational solution of the dual problem.

  3. 77 FR 74915 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-18

    ... Office of Foreign Assets Control Additional Designations, Foreign Narcotics Kingpin Designation Act... entity whose property and interests in property have been blocked pursuant to the Foreign Narcotics... narcotics traffickers and their organizations on a worldwide basis. It provides a statutory framework...

  4. 76 FR 25406 - 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... narcotics traffickers and their organizations on a worldwide basis. It provides a statutory framework...

  5. 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.

  6. 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.

  7. 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…

  8. 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.

  9. Theoretical constraints in the design of multivariable control systems

    NASA Technical Reports Server (NTRS)

    Rynaski, E. G.; Mook, D. J.

    1993-01-01

    The theoretical constraints inherent in the design of multivariable control systems were defined and investigated. These constraints are manifested by the system transmission zeros that limit or bound the areas in which closed loop poles and individual transfer function zeros may be placed. These constraints were investigated primarily in the context of system decoupling or non-interaction. It was proven that decoupling requires the placement of closed loop poles at the system transmission zeros. Therefore, the system transmission zeros must be minimum phase to guarantee a stable decoupled system. Once decoupling has been accomplished, the remaining part of the system exhibits transmission zeros at infinity, so nearly complete design freedom is possible in terms of placing both poles and zeros of individual closed loop transfer functions. A general, dynamic inversion model following system architecture was developed that encompasses both the implicit and explicit configuration. Robustness properties are developed along with other attributes of this type of system. Finally, a direct design is developed for the longitudinal-vertical degrees of freedom of aircraft motion to show how a direct lift flap can be used to improve the pitch-heave maneuvering coordination for enhanced flying qualities.

  10. Parallel transmission RF pulse design with strict temperature constraints.

    PubMed

    Deniz, Cem M; Carluccio, Giuseppe; Collins, Christopher

    2017-02-10

    RF safety in parallel transmission (pTx) is generally ensured by imposing specific absorption rate (SAR) limits during pTx RF pulse design. There is increasing interest in using temperature to ensure safety in MRI. In this work, we present a local temperature correlation matrix formalism and apply it to impose strict constraints on maximum absolute temperature in pTx RF pulse design for head and hip regions. Electromagnetic field simulations were performed on the head and hip of virtual body models. Temperature correlation matrices were calculated for four different exposure durations ranging between 6 and 24 min using simulated fields and body-specific constants. Parallel transmission RF pulses were designed using either SAR or temperature constraints, and compared with each other and unconstrained RF pulse design in terms of excitation fidelity and safety. The use of temperature correlation matrices resulted in better excitation fidelity compared with the use of SAR in parallel transmission RF pulse design (for the 6 min exposure period, 8.8% versus 21.0% for the head and 28.0% versus 32.2% for the hip region). As RF exposure duration increases (from 6 min to 24 min), the benefit of using temperature correlation matrices on RF pulse design diminishes. However, the safety of the subject is always guaranteed (the maximum temperature was equal to 39°C). This trend was observed in both head and hip regions, where the perfusion rates are very different.

  11. 76 FR 58562 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-21

    ... THE TREASURY Office of Foreign Assets Control Additional Designations, Foreign Narcotics Kingpin... individuals whose property and interests in property have been blocked pursuant to the Foreign Narcotics... activities of significant foreign narcotics traffickers and their organizations on a worldwide basis with...

  12. 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.

  13. 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.

  14. Sensitivity of the optimal preliminary design of a transport to operational constraints and performance index

    NASA Technical Reports Server (NTRS)

    Sliwa, S. M.

    1980-01-01

    Constrained parameter optimization was used to perform the optimal preliminary design of a medium range transport configuration. The impact of choosing a performance index was studied and the required fare for a 15 percent return-on-investment was proposed as a figure-of-merit. A number of design constants and constraint functions were systematically varied to document the sensitivities of the optimal design to a variety of economic and technological assumptions. Additionally, a comparison is made for each of the parameter variations between the baseline configuration and the optimally redesigned configuration.

  15. Geometric constraints for shape and topology optimization in architectural design

    NASA Astrophysics Data System (ADS)

    Dapogny, Charles; Faure, Alexis; Michailidis, Georgios; Allaire, Grégoire; Couvelas, Agnes; Estevez, Rafael

    2017-02-01

    This work proposes a shape and topology optimization framework oriented towards conceptual architectural design. A particular emphasis is put on the possibility for the user to interfere on the optimization process by supplying information about his personal taste. More precisely, we formulate three novel constraints on the geometry of shapes; while the first two are mainly related to aesthetics, the third one may also be used to handle several fabrication issues that are of special interest in the device of civil structures. The common mathematical ingredient to all three models is the signed distance function to a domain, and its sensitivity analysis with respect to perturbations of this domain; in the present work, this material is extended to the case where the ambient space is equipped with an anisotropic metric tensor. Numerical examples are discussed in two and three space dimensions.

  16. 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.

  17. Impact of structural optimization with aeroelastic/multidisciplinary constraints on helicopter rotor design

    NASA Technical Reports Server (NTRS)

    Friedmann, Peretz P.

    1992-01-01

    This paper presents a review of the state-of-the-art in the field of structural optimization when applied to vibration reduction of helicopters in forward flight with aeroelastic and multidisciplinary constraints. It emphasizes the application of the modern approach where the optimization is formulated as a mathematical programming problem and the objective function consists of the vibration levels at the hub and behavior constraints are imposed on the blade frequencies, aeroelastic stability margins as well as on a number of additional ingredients which can have a significant effect on the overall performance and flight mechanics of the helicopter. It is shown that the integrated multidisciplinary optimization of rotorcraft offers the potential for substantial improvements which can be achieved by careful preliminary design and analysis without requiring additional hardware such as rotor vibration absorbers or isolation systems.

  18. 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.

  19. 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.

  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.

  1. 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

  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. Scheduled Controller Design of Congestion Control Considering Network Resource Constraints

    NASA Astrophysics Data System (ADS)

    Naito, Hiroyuki; Azuma, Takehito; Fujita, Masayuki

    In this paper, we consider a dynamical model of computer networks and derive a synthesis method for congestion control. First, we show a model of TCP/AQM (Transmission Control Protocol/Active Queue Management) as a dynamical model of computer networks. The dynamical model of TCP/AQM networks consists of models of TCP window size, queue length and AQM mechanisms. Second, we propose to describe the dynamical model of TCP/AQM networks as linear systems with self-scheduling parameters, which also depend on information delay. Here we focus on the constraints on the maximum queue length and TCP window-size, which are the network resources in TCP/AQM networks. We derive TCP/AQM networks as the LPV system (linear parameter varying system) with information delay and self-scheduling parameter. We design a memoryless state feedback controller of the LPV system based on a gain-scheduling method. Finally, the effectiveness of the proposed method is evaluated by using MATLAB and the well-known ns-2 (Network Simulator Ver.2) simulator.

  4. 78 FR 70630 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-26

    ... Designations, Foreign Narcotics Kingpin Designation Act AGENCY: Office of Foreign Assets Control, Treasury... been blocked pursuant to the Foreign Narcotics Kingpin Designation Act (``Kingpin Act'') (21 U.S.C... narcotics traffickers and their organizations on a worldwide basis. It provides a statutory framework...

  5. 77 FR 29755 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-18

    ..., Foreign Narcotics Kingpin Designation Act AGENCY: Office of Foreign Assets Control, Treasury. ACTION... to the Foreign Narcotics Kingpin Designation Act (``Kingpin Act'') (21 U.S.C. 1901-1908, 8 U.S.C.... The Kingpin Act establishes a program targeting the activities of significant foreign...

  6. 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

  7. Designing a mixture experiment when the components are subject to a nonlinear multiple-component constraint

    SciTech Connect

    Piepel, Greg F.; Cooley, Scott K.; Vienna, John D.; Crum, Jarrod V.

    2015-12-14

    This article presents a case study of developing an experimental design for a constrained mixture experiment when the experimental region is defined by single-component constraints (SCCs), linear multiple-component constraints (MCCs), and a nonlinear MCC. Traditional methods and software for designing constrained mixture experiments with SCCs and linear MCCs are not directly applicable because of the nonlinear MCC. A modification of existing methodology to account for the nonlinear MCC was developed and is described in this article. The case study involves a 15-component nuclear waste glass example in which SO3 is one of the components. SO3 has a solubility limit in glass that depends on the composition of the balance of the glass. A goal was to design the experiment so that SO3 would not exceed its predicted solubility limit for any of the experimental glasses. The SO3 solubility limit had previously been modeled by a partial quadratic mixture (PQM) model expressed in the relative proportions of the 14 other components. The PQM model was used to construct a nonlinear MCC in terms of all 15 components. In addition, there were SCCs and linear MCCs. This article discusses the waste glass example and how a layered design was generated to (i) account for the SCCs, linear MCCs, and nonlinear MCC and (ii) meet the goals of the study.

  8. 75 FR 36474 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-25

    ... designated pursuant to the Kingpin Act: 1. MELO PERILLA, Jose Cayetano, c/o CARILLANCA COLOMBIA Y CIA S EN CS..., Jose Cayetano, c/o CARILLANCA COLOMBIA Y CIA S EN CS, Bogota, Colombia; c/o CARILLANCA S.A., San...

  9. 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.

  10. 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.

  11. Additive Manufacturing of Metal Cellular Structures: Design and Fabrication

    NASA Astrophysics Data System (ADS)

    Yang, Li; Harrysson, Ola; Cormier, Denis; West, Harvey; Gong, Haijun; Stucker, Brent

    2015-03-01

    With the rapid development of additive manufacturing (AM), high-quality fabrication of lightweight design-efficient structures no longer poses an insurmountable challenge. On the other hand, much of the current research and development with AM technologies still focuses on material and process development. With the design for additive manufacturing in mind, this article explores the design issue for lightweight cellular structures that could be efficiently realized via AM processes. A unit-cell-based modeling approach that combines experimentation and limited-scale simulation was demonstrated, and it was suggested that this approach could potentially lead to computationally efficient design optimizations with the lightweight structures in future applications.

  12. 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.

  13. Design optimization of heat transfer and fluidic devices by using additive manufacturing

    NASA Astrophysics Data System (ADS)

    Kumar, Nikhil

    After the development of additive manufacturing technology in the 1980s, it has found use in many applications like aerospace, automotive, marine, machinery, consumer and electronic applications. In recent time, few researchers have worked on the applications of additive manufacturing for heat transfer and fluidic devices. As the world has seen a drastic increase in population in last decades which have put stress on already scarce energy resources, optimization of energy devices which include energy storing devices, heat transfer devices, energy capturing devices etc. is need for the hour. Design of energy devices is often constrained by manufacturing constraints thus current design of energy devices is not an optimized one. In this research we want to conceptualize, design and manufacture optimized heat transfer and fluidic devices by exploiting the advantages provided by additive manufacturing. We want to benefit from the fact that very intricate geometry and desired surface finish can be obtained by using additive manufacturing. Additionally, we want to compare the efficacy of our designed device with conventional devices. Work on usage of Additive manufacturing for increasing efficiency of heat transfer devices can be found in the literature. We want to extend this approach to other heat transfer devices especially tubes with internal flow. By optimizing the design of energy systems we hope to solve current energy shortage and help conserve energy for future generation. We will also extend the application of additive manufacturing technology to fabricate "device for uniform flow distribution".

  14. 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.

  15. Design and fabrication of the progressive addition lenses

    NASA Astrophysics Data System (ADS)

    Qin, Linling; Qian, Lin; Yu, Jingchi

    2011-11-01

    The use of progressive addition lenses (PALs) for the correction of presbyopia has increased dramatically in recent years. These lenses are now being used as the preferred alternative to bifocal and trifocal lenses in many parts of the world. Progressive addition lenses are a kind of opthalmic lenses with freeform surface. The surface curvature of the Progressive addition lenses varies gradually from a minimum value in the upper area, to a maximum value in the lower area. Thus a PAL has a surface with three zones which have very small astigmatism: far-view zone, near-view zone, and intermediate zone. The far view zone and near view zone have relatively constant powers and connected by the intermediate zone with power varies progressively. The design and fabrication technologies of progressive addition lenses have fast progresses because of the massive development of the optical simulation software, multi-axis ultraprecision machining technologies and CNC machining technologies. The design principles of progressive addition lenses are discussed in a historic review. Several kinds of design methods are illustrated, and their advantages and disadvantages are also represented. In the current study, it is shown that the optical characteristics of the different progressive addition lenses designs are significantly different from one another. The different fabrication technologies of Progressive addition lenses are also discussed in the paper. Plastic injection molding and precision-machine turning are the common fabrication technologies for exterior PALs and Interior PALs respectively.

  16. 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.

  17. Conformational constraint in protein ligand design and the inconsistency of binding entropy.

    PubMed

    Udugamasooriya, D Gomika; Spaller, Mark R

    2008-08-01

    It is an accepted practice in ligand design to introduce conformational constraint with the expectation of improving affinity, justified by the theoretical possibility that an unfavorable change in binding entropy will be reduced. This rationale of minimizing the entropic penalty through imposing structural constraints upon a ligand, however, has been voiced more often than verified. Here we examine three modified cyclic peptides, along with multiple versions of their linear control analogs, and determine their thermodynamic parameters when binding the same host, the third PDZ domain (PDZ3) of the mammalian postsynaptic density-95 (PSD-95) protein. To begin a two-stage investigation, the initial evaluation involved solution binding studies with isothermal titration calorimetry (ITC), which provided the changes in Gibbs free energy (DeltaG), enthalpy (DeltaH), and entropy (TDeltaS) upon formation of the protein-ligand complex. In the second stage, a selected macrocycle along with two matched linear controls were subjected to more rigorous analysis by ITC, which included (1) change in heat of buffer ionization (DeltaH(ion)) titrations, to examine the role of proton transfer events; (2) change in heat capacity (DeltaC(p)) determinations, to indirectly probe the nature of the binding surface; and (3) osmotic stress experiments, to evaluate desolvation effects and quantitate water release. Together, these demonstrate that the entropic relationship between a macrocyclic ligand and a linear counterpart can be a complex one that is difficult to rationalize. Further, the addition of constraint can, counterintuitively, lead to a less favorable change in binding entropy. This underscores the need to use matched linear control ligands to assure that comparisons are made in a meaningful manner.

  18. 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

  19. 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…

  20. 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.

  1. Neural Network Control-Based Adaptive Learning Design for Nonlinear Systems With Full-State Constraints.

    PubMed

    Liu, Yan-Jun; Li, Jing; Tong, Shaocheng; Chen, C L Philip

    2016-07-01

    In order to stabilize a class of uncertain nonlinear strict-feedback systems with full-state constraints, an adaptive neural network control method is investigated in this paper. The state constraints are frequently emerged in the real-life plants and how to avoid the violation of state constraints is an important task. By introducing a barrier Lyapunov function (BLF) to every step in a backstepping procedure, a novel adaptive backstepping design is well developed to ensure that the full-state constraints are not violated. At the same time, one remarkable feature is that the minimal learning parameters are employed in BLF backstepping design. By making use of Lyapunov analysis, we can prove that all the signals in the closed-loop system are semiglobal uniformly ultimately bounded and the output is well driven to follow the desired output. Finally, a simulation is given to verify the effectiveness of the method.

  2. Placement with Symmetry Constraints for Analog IC Layout Design Based on Tree Representation

    NASA Astrophysics Data System (ADS)

    Hirakawa, Natsumi; Fujiyoshi, Kunihiro

    Symmetry constrains are the constraints that the given cells should be placed symmetrically in design of analog ICs. We use O-tree to represent placements and propose a decoding algorithm which can obtain one of the minimum placements satisfying the constraints. The decoding algorithm uses linear programming, which is too much time consuming. Therefore we propose a graph based method to recognize if there exists no placement satisfying both the given symmetry and O-tree constraints, and use the method before application of linear programming. The effectiveness of the proposed method was shown by computational experiments.

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

    NASA Technical Reports Server (NTRS)

    O’Neal, T. 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. This paper discusses the impacts of the DMLS fabrication technique on the design of the turbopump and lessons learned during DMLS hardware fabrication and material testing.

  4. 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.

  5. 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.

  6. 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.

  7. 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 ).

  8. 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.

  9. 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.

  10. 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.

  11. A Model To Address Design Constraints of Training Delivered via Satellite. Study Number Eight.

    ERIC Educational Resources Information Center

    Montler, Joseph; Geroy, Gary D.

    This document: summarizes how some companies are addressing the design constraints involved in using satellite technology to deliver training, presents a model aimed at examining cost effectiveness of the satellite option, and includes a guide to designing instructional materials for delivery by satellite. A survey of 39 organizations, 12…

  12. 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.

  13. Synthetic aperture radar range - Azimuth ambiguity design and constraints

    NASA Technical Reports Server (NTRS)

    Mehlis, J. G.

    1980-01-01

    Problems concerning the design of a system for mapping a planetary surface with a synthetic aperture radar (SAR) are considered. Given an ambiguity level, resolution, and swath width, the problems are related to the determination of optimum antenna apertures and the most suitable pulse repetition frequency (PRF). From the set of normalized azimuth ambiguity ratio curves, the designer can arrive at the azimuth antenna length, and from the sets of normalized range ambiguity ratio curves, he can arrive at the range aperture length or pulse repetition frequency. A procedure based on this design method is shown in an example. The normalized curves provide results for a SAR using a uniformly or cosine weighted rectangular antenna aperture.

  14. 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.

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

    NASA Technical Reports Server (NTRS)

    Jaunky, Navin; Knight, Norman F., Jr.; Ambur, Damodar R.

    1998-01-01

    A design strategy for optimal design of composite grid-stiffened cylinders subjected to global and local buckling constraints and, strength constraints is developed using a discrete optimizer based on a genetic algorithm. An improved smeared stiffener theory is used for the global analysis. Local buckling of skin segments are assessed using a Rayleigh-Ritz method that accounts for material anisotropy. The local buckling of stiffener segments are also assessed. Constraints on the axial membrane strain in the skin and stiffener segments are imposed to include strength criteria in the grid-stiffened cylinder design. Design variables used in this study are the axial and transverse stiffener spacings, stiffener height and thickness, skin laminate stacking sequence, and stiffening configuration, where herein 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 is 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 configuration.

  16. Protein design by sampling an undirected graphical model of residue constraints.

    PubMed

    Thomas, John; Ramakrishnan, Naren; Bailey-Kellogg, Chris

    2009-01-01

    This paper develops an approach for designing protein variants by sampling sequences that satisfy residue constraints encoded in an undirected probabilistic graphical model. Due to evolutionary pressures on proteins to maintain structure and function, the sequence record of a protein family contains valuable information regarding position-specific residue conservation and coupling (or covariation) constraints. Representing these constraints with a graphical model provides two key benefits for protein design: a probabilistic semantics enabling evaluation of possible sequences for consistency with the constraints, and an explicit factorization of residue dependence and independence supporting efficient exploration of the constrained sequence space. We leverage these benefits in developing two complementary MCMC algorithms for protein design: constrained shuffling mixes wild-type sequences positionwise and evaluates graphical model likelihood, while component sampling directly generates sequences by sampling clique values and propagating to other cliques. We apply our methods to design WW domains. We demonstrate that likelihood under a model of wild-type WWs is highly predictive of foldedness of new WWs. We then show both theoretical and rapid empirical convergence of our algorithms in generating high-likelihood, diverse new sequences. We further show that these sequences capture the original sequence constraints, yielding a model as predictive of foldedness as the original one.

  17. Systematic design of a magneto-rheological fluid embedded pneumatic vibration isolator subject to practical constraints

    NASA Astrophysics Data System (ADS)

    Zhu, Xiaocong; Jing, Xingjian; Cheng, Li

    2012-03-01

    A systematic design of a magneto-rheological fluid embedded pneumatic vibration isolator (MrEPI) considering practical constraints and optimal performance is proposed. The design procedure basically consists of three steps, i.e. system level design, component level design and practical realization. The system level design involves synthesizing appropriate non-dimensional system parameters of pneumatic spring and MR damper elements based on parameter sensitivity analysis considering requirements for compact and efficient hardware utilization. The component level design involves optimal design of the MR valve by minimizing an objective function in terms of non-dimensional geometric, material and excitation parameters, and guaranteeing required performance in the worst cases. Then practical realization involves determining actual plant parameters from the non-dimensional analysis in system and component level designs with the considerations of practical requirements/constraints. To verify the effectiveness of this optimization procedure, the semi-active vibration control performance of the optimized MrEPI subject to harmonic disturbances is evaluated, which shows good isolation performance in all tested cases. This study actually provides a systematic method for the optimal analysis and design of all those nonlinear vibration isolators consisting of pneumatic spring and MR damper elements. This is achieved firstly by developing effective sensitivity analysis of dominant design parameters upon the adjustable stiffness and damping capacity irrespective of bulky or small system mass configuration and subsequently via a systematic realization design with the consideration of practical constraints in applications.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Minimum weight design of rotorcraft blades with multiple frequency and stress constraints

    NASA Technical Reports Server (NTRS)

    Chattopadhyay, Aditi; Walsh, Joanne L.

    1988-01-01

    Minimum weight designs of helicopter rotor blades with constraints on multiple coupled flap-lag natural frequencies are studied. Constraints are imposed on the minimum value of the blade autorotational inertia to ensure sufficient rotary inertia to autorotate in case of engine failure and on stresses to guard against structural failure due to blade centrifugal forces. Design variables include blade taper ratio, dimensions of the box beam located inside the airfoil and magnitudes of nonstructural weights. The program CAMRAD is used for the blade modal analysis; the program CONMIN is used for the optimization. A linear approximation involving Taylor series expansion is used to reduce the analysis effort. The procedure contains a sensitivity analysis consisting of analytical derivatives for objective function and constraints on autorotational inertia and stresses. Central finite difference derivatives are used for frequency constraints. Optimal designs are obtained for both rectangular and tapered blades. Using this method, it is possible to design a rotor blade with reduced weight, when compared to a baseline blade, while satisfying all the imposed design requirements.

  5. 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.

  6. 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

  7. Design of structure/control systems with transient response constraints exhibiting relative minima

    NASA Technical Reports Server (NTRS)

    Sepulveda, A. E.; Jin, I. M.

    1992-01-01

    Structural optimization problems involving dynamic behavior constraints often exhibit nonconvex design spaces. The direct application of a global optimization algorithm requires a large number of function evaluations which in term require a large number of dynamic structural analyses. This work presents a strategy aimed at finding the global optimum for problems with transient dynamic behavior constraints based on approximation concepts. The method consists of generating and solving a sequence of approximate problems using a global optimizer. The approximations are explicit and capture the inherent nonconvexity of the exact functions. A simple example problem is presented.

  8. Panel Flutter Constraints: Analytic Sensitivities and Approximations Including Planform Shape Design Variables

    NASA Technical Reports Server (NTRS)

    Livne, Eli; Mineau, David

    1997-01-01

    Analytical sensitivities of panel flutter constraints with respect to panel shape as well as thickness and material properties are derived and numerically tested. Cases of fixed in-plane loads and cases in which in-plane loads are variable (depending on panel and overall wing shape as well as material and sizing design variables) are considered. Accuracy of approximations and range of move limits required are studied in preparation for integration with nonlinear programming/approximation concept aeroelastic design synthesis methodology.

  9. 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

  10. Physical constraints on biological integral control design for homeostasis and sensory adaptation.

    PubMed

    Ang, Jordan; McMillen, David R

    2013-01-22

    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.

  11. 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.

  12. 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.

  13. 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.

  14. Automated design optimization of supersonic airplane wing structures under dynamic constraints.

    NASA Technical Reports Server (NTRS)

    Fox, R. L.; Miura, H.; Rao, S. S.

    1972-01-01

    The problems of the preliminary and first level detail design of supersonic aircraft wings are stated as mathematical programs and solved using automated optimum design techniques. The problem is approached in two phases: the first is a simplified equivalent plate model in which the envelope, plan form and structural parameters are varied to produce a design, the second is a finite element model with fixed configuration in which the material distribution is varied. Constraints include flutter, aeroelastically computed stresses and deflections, natural frequency and a variety of geometric limitations. The Phase I objective is a combination of weight and drag while Phase II is a weight minimization.

  15. The use of the Regier number in the structural design with flutter constraints

    NASA Technical Reports Server (NTRS)

    Dunn, H. J.; Doggett, Robert V., Jr.

    1994-01-01

    This preliminary investigation introduces the use of the Regier number as a flutter constraint criterion for aeroelastic structural optimization. Artificial neural network approximations are used to approximate the flutter criterion requirements as a function of the design Mach number and the parametric variables defining the aspect ratio, center of gravity, taper ratio, mass ratio, and pitch inertia of the wing. The presented approximations are simple enough to be used in the preliminary design stage without a well defined structural model. An example problem for a low-speed, high-aspect-ratio, light-aircraft wing is presented. The example problem is analyzed for the flutter Mach number using doublet lattice aerodynamics and the PK solution method. The use of the Regier number constraint criterion to optimize the example problem for minimum structural mass while maintaining a constant flutter Mach number is demonstrated.

  16. 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.

  17. 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.

  18. 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.

  19. 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)

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. Exploring the impact of mask making constraints on double patterning design rules

    NASA Astrophysics Data System (ADS)

    Dam, Thuc; Sinn, Robert; Rissman, Paul; Gleason, Bob

    2011-11-01

    In order to achieve an economical design-to-mask (DTM) development cycle in the low k1 domain, designers, lithographers, and mask makers needed to move away from many sequentially isolated developmental activities onto one collaborative environment managed by a computational lithography platform that integrates their respective ecosystems. 1,2 A successful development cycle used to be achievable by designers providing designs to lithographers, who then provided RET/OPC solutions to realize designs, but once k1 fell below a certain level, the lithographers could not provide solutions to realize some critical designs, which then required feedback to designers for further redesigns requiring further lithographic evaluation cycles. So collaboration and automations between lithographers and designers became necessary to reduce feedback loops and development cycle time. RET and design solutions also were impacted by mask making, and so mask maker's feedback on MRC and other constraints needed to be integrated for all three groups to achieve an economical DTM. As many lithographers attempted to print sub-80 nm pitches with 193 nm wavelength, it became necessary to use double patterning to achieve feature resolution. With the effective pitch doubling on each split layer, there could be significant increased design rule freedom for certain complex design situations. Using an integrated computational lithographic platform, one could find design space sweet spots that could further achieve optimal lithographic performance. In this paper, the optimization of design rules (DRD) for double pattern designs (~60 nm pitch) was explored with the mask maker's perspective. The experiment to be presented started with a 2x nm design set of clips. Each set of clips underwent size/width/space/pitch variations to generate a design space, and then each design space underwent SMO with an inverse lithography technology (ILT) engine using various mask MRC's and manhattan segmentations. The

  5. 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.

  6. Contractive control design for Navier-Stokes systems with the incompressibility constraint relaxed

    NASA Astrophysics Data System (ADS)

    Yu, Huan; Beyhaghi, Pooriya; Bewley, Thomas; Flow Control Lab Team

    2015-11-01

    One approach to the linear stabilization of near-wall transitional channel flow is via the Orr-Sommerfeld/Squire equations. This formulation is delicate, as it reduces the three momentum equations and the divergence-free constraint of the incompressible NSE down to a highly non-normal set of two equations, one for the wall-normal velocity and one for the wall-normal vorticity, and involves inverting a Laplacian with boundary conditions embedded. A simpler formulation for the purpose of control design is given by simply dropping the divergence-free constraint from the problem considered altogether, and at the same time dropping the pressure gradient from the momentum equations, which acts to enforce this constraint. What remains is three coupled Burgers equations. In general, there is no relationship between the stability of such constrained and unconstrained systems; however, if the unconstrained system is contractive (a condition stronger than just stability), the constrained system is also contractive. We have investigated this approach to control design for NS systems. We have proved a fundamental limit: if an uncontrolled, unconstrained channel flow system is not contractive, there is no boundary control that can make it contractive.

  7. Optimized and Automated design of Plasma Diagnostics for Additive Manufacture

    NASA Astrophysics Data System (ADS)

    Stuber, James; Quinley, Morgan; Melnik, Paul; Sieck, Paul; Smith, Trevor; Chun, Katherine; Woodruff, Simon

    2016-10-01

    Despite having mature designs, diagnostics are usually custom designed for each experiment. Most of the design can be now be automated to reduce costs (engineering labor, and capital cost). We present results from scripted physics modeling and parametric engineering design for common optical and mechanical components found in many plasma diagnostics and outline the process for automated design optimization that employs scripts to communicate data from online forms through proprietary and open-source CAD and FE codes to provide a design that can be sent directly to a printer. As a demonstration of design automation, an optical beam dump, baffle and optical components are designed via an automated process and printed. Supported by DOE SBIR Grant DE-SC0011858.

  8. 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.

  9. 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.

  10. A methodology for the efficient integration of transient constraints in the design of aircraft dynamic systems

    NASA Astrophysics Data System (ADS)

    Phan, Leon L.

    The motivation behind this thesis mainly stems from previous work performed at Hispano-Suiza (Safran Group) in the context of the European research project "Power Optimised Aircraft". Extensive testing on the COPPER Bird RTM, a test rig designed to characterize aircraft electrical networks, demonstrated the relevance of transient regimes in the design and development of dynamic systems. Transient regimes experienced by dynamic systems may have severe impacts on the operation of the aircraft. For example, the switching on of a high electrical load might cause a network voltage drop inducing a loss of power available to critical aircraft systems. These transient behaviors are thus often regulated by dynamic constraints, requiring the dynamic signals to remain within bounds whose values vary with time. The verification of these peculiar types of constraints, which generally requires high-fidelity time-domain simulation, intervenes late in the system development process, thus potentially causing costly design iterations. The research objective of this thesis is to develop a methodology that integrates the verification of dynamic constraints in the early specification of dynamic systems. In order to circumvent the inefficiencies of time-domain simulation, multivariate dynamic surrogate models of the original time-domain simulation models are generated, building on a nonlinear system identification technique using wavelet neural networks (or wavenets), which allow the multiscale nature of transient signals to be captured. However, training multivariate wavenets can become computationally prohibitive as the number of design variables increases. Therefore, an alternate approach is formulated, in which dynamic surrogate models using sigmoid-based neural networks are used to emulate the transient behavior of the envelopes of the time-domain response. Thus, in order to train the neural network, the envelopes are extracted by first separating the scales of the dynamic response

  11. Effective Domain Partitioning for Multi-Clock Domain IP Core Wrapper Design under Power Constraints

    NASA Astrophysics Data System (ADS)

    Yu, Thomas Edison; Yoneda, Tomokazu; Zhao, Danella; Fujiwara, Hideo

    The rapid advancement of VLSI technology has made it possible for chip designers and manufacturers to embed the components of a whole system onto a single chip, called System-on-Chip or SoC. SoCs make use of pre-designed modules, called IP-cores, which provide faster design time and quicker time-to-market. Furthermore, SoCs that operate at multiple clock domains and very low power requirements are being utilized in the latest communications, networking and signal processing devices. As a result, the testing of SoCs and multi-clock domain embedded cores under power constraints has been rapidly gaining importance. In this research, a novel method for designing power-aware test wrappers for embedded cores with multiple clock domains is presented. By effectively partitioning the various clock domains, we are able to increase the solution space of possible test schedules for the core. Since previous methods were limited to concurrently testing all the clock domains, we effectively remove this limitation by making use of bandwidth conversion, multiple shift frequencies and properly gating the clock signals to control the shift activity of various core logic elements. The combination of the above techniques gains us greater flexibility when determining an optimal test schedule under very tight power constraints. Furthermore, since it is computationally intensive to search the entire expanded solution space for the possible test schedules, we propose a heuristic 3-D bin packing algorithm to determine the optimal wrapper architecture and test schedule while minimizing the test time under power and bandwidth constraints.

  12. Reinforcement-Learning-Based Robust Controller Design for Continuous-Time Uncertain Nonlinear Systems Subject to Input Constraints.

    PubMed

    Liu, Derong; Yang, Xiong; Wang, Ding; Wei, Qinglai

    2015-07-01

    The design of stabilizing controller for uncertain nonlinear systems with control constraints is a challenging problem. The constrained-input coupled with the inability to identify accurately the uncertainties motivates the design of stabilizing controller based on reinforcement-learning (RL) methods. In this paper, a novel RL-based robust adaptive control algorithm is developed for a class of continuous-time uncertain nonlinear systems subject to input constraints. The robust control problem is converted to the constrained optimal control problem with appropriately selecting value functions for the nominal system. Distinct from typical action-critic dual networks employed in RL, only one critic neural network (NN) is constructed to derive the approximate optimal control. Meanwhile, unlike initial stabilizing control often indispensable in RL, there is no special requirement imposed on the initial control. By utilizing Lyapunov's direct method, the closed-loop optimal control system and the estimated weights of the critic NN are proved to be uniformly ultimately bounded. In addition, the derived approximate optimal control is verified to guarantee the uncertain nonlinear system to be stable in the sense of uniform ultimate boundedness. Two simulation examples are provided to illustrate the effectiveness and applicability of the present approach.

  13. 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.

  14. 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.

  15. A methodology for aeroelastic constraint analysis in a conceptual design environment

    NASA Astrophysics Data System (ADS)

    de Baets, Peter Wilfried Gaston

    The objective of this study is the infusion of aeroelastic constraint knowledge into the design space. The mapping of such aeroelastic information in the conceptual design space has long been a desire of the design community. The conceptual design phase of an aircraft is a multidisciplinary environment and has the most influence on the future design of the vehicle. However, sufficient results cannot he obtained in a timely enough manner to materially contribute to early design decisions. Furthermore, the natural division of the engineering team into specialty groups is not well supported by the monolithic aerodynamic-structures codes typically used in modern aeroelastic analysis. The research examines how the Bi-Level Integrated System Synthesis decomposition technique can be adapted to perform as the conceptual aeroelastic design tool. The study describes a comprehensive solution of the aeroelastic coupled problem cast in this decomposition format and implemented in an integrated framework. The method is supported by application details of a proof of concept high speed vehicle. Physics-based codes such as finite element and an aerodynamic panel method are used to model the high-definition geometric characteristics of the vehicle. A synthesis and sizing code was added to referee the conflicts that arise between the two disciplines. This research's novelty lies in four points. First is the use of physics-based tools at the conceptual design phase to calculate the aeroelastic properties. Second is the projection of flutter and divergence velocity constraint lines in a power loading versus wing loading graph. Third is the aeroelastic assessment time reduction, which has moved from a matter of years to months. Lastly, this assessment allowed verification of the impact of changing velocity, altitude, and angle of attack on the aeroelastic properties. This then allowed identification of robust design space with respect to these three mission properties. The method

  16. 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…

  17. 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.

  18. Design Optimization of Concentric Tube Robots Based on Task and Anatomical Constraints.

    PubMed

    Bedell, Chris; Lock, Jesse; Gosline, Andrew; Dupont, Pierre E

    2011-05-09

    Concentric tube robots are a novel continuum robot technology that is well suited to minimally invasive surgeries inside small body cavities such as the heart. These robots are constructed of concentrically combined pre-curved elastic tubes to form 3D curves. Each telescopic section of the robot is either of fixed or variable curvature. One advantage of this approach is that the component tube curvatures, lengths and stiffnesses can easily be fabricated to be procedure- and patient-specific. This paper proposes an optimization framework for solving the robot design problem. Given a 3D description of the constraining anatomy, the number of fixed and variable curvature robot sections and a tip workspace description, the algorithm solves for the robot design that possesses the desired workspace, remains inside the anatomical constraints and minimizes the curvature and length of all sections. The approach is illustrated in the context of beating-heart closure of atrial septal defects.

  19. 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.

  20. 2015 Summer Design Challenge: Team A&E (2241) Additively Manufactured Discriminator.

    SciTech Connect

    Miller, Sarah E.; Moore, Brandon James

    2016-11-01

    Current discriminator designs are based on historical designs and traditional manufacturing methods. The goal of this project was to form non-traditional groups to create novel discriminator designs by taking advantage of additive manufacturing. These designs would expand current discriminator designs and provide insight on the applicability of additive manufacturing for future projects. Our design stretched the current abilities of additive manufacturing and noted desired improvements for the future. Through collaboration with NSC, we noted several additional technologies which work well with additive manufacturing such as topology optimization and CT scanning and determined how these technologies could be improved to better combine with additive manufacturing.

  1. 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

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

    PubMed

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

    2015-02-03

    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.

  3. 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

  4. 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.

  5. The WFIRST Interim Design Reference Mission: Capabilities, Constraints, and Open Questions

    NASA Technical Reports Server (NTRS)

    Kruk, Jeffrey W.

    2012-01-01

    The Project Office and Science Definition Team for the Wide-Field Infrared Survey Telescope (WFIRST) are in the midst of a pre-Phase A study to establish a Design Reference Mission (DRM). An Interim report was released in June 2011, with a final report due later in 2012. The predicted performance of the Interim DRM Observatory will be described, including optical quality, observing efficiency, and sensitivity for representative observing scenarios. Observing constraints and other limitations on performance will also be presented, with an emphasis on potential Guest Observer programs. Finally, a brief status update will be provided on open trade studies of interest to the scientific community. The final DRM may differ from the Interim DRM presented here. However, the underlying requirements of the scientific programs are not expected to change, hence the capabilities of the IDRM are likely to be maintained even if the implementation changes in significant ways.

  6. 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.

  7. 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.

  8. 49 CFR 173.466 - Additional tests for Type A packagings designed for liquids and gases.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Additional tests for Type A packagings designed...) Materials § 173.466 Additional tests for Type A packagings designed for liquids and gases. (a) In addition to the tests prescribed in § 173.465, Type A packagings designed for liquids and gases must...

  9. 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.

  10. Constraint on Additional Planets in Planetary Systems Discovered Through the Channel of High-magnification Gravitational Microlensing Events

    NASA Astrophysics Data System (ADS)

    Shin, I.-G.; Han, C.; Choi, J.-Y.; Hwang, K.-H.; Jung, Y.-K.; Park, H.

    2015-04-01

    High-magnification gravitational microlensing events provide an important channel of detecting planetary systems with multiple giants located at their birth places. In order to investigate the potential existence of additional planets, we reanalyze the light curves of the eight high-magnification microlensing events, for each of which a single planet was previously detected. The analyzed events include OGLE-2005-BLG-071, OGLE-2005-BLG-169, MOA-2007-BLG-400, MOA-2008-BLG-310, MOA-2009-BLG-319, MOA-2009-BLG-387, MOA-2010-BLG-477, and MOA-2011-BLG-293. We find that including an additional planet improves fits with {Δ }{{χ }2}\\lt 80 for seven out of eight analyzed events. For MOA-2009-BLG-319, the improvement is relatively big with {Δ }{{χ }2}∼ 143. From inspection of the fits, we find that the improvement of the fits is attributed to systematics in data. Although no clear evidence of additional planets is found, it is still possible to constrain the existence of additional planets in the parameter space. For this purpose, we construct exclusion diagrams showing the confidence levels excluding the existence of an additional planet as a function of its separation and mass ratio. We also present the exclusion ranges of additional planets with 90% confidence level for Jupiter-, Saturn-, and Uranus-mass planets.

  11. 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

  12. Global reverse supply chain design for solid waste recycling under uncertainties and carbon emission constraint.

    PubMed

    Xu, Zhitao; Elomri, Adel; Pokharel, Shaligram; Zhang, Qin; Ming, X G; Liu, Wenjie

    2017-03-18

    The emergence of concerns over environmental protection, resource conservation as well as the development of logistics operations and manufacturing technology has led several countries to implement formal collection and recycling systems of solid waste. Such recycling system has the benefits of reducing environmental pollution, boosting the economy by creating new jobs, and generating income from trading the recyclable materials. This leads to the formation of a global reverse supply chain (GRSC) of solid waste. In this paper, we investigate the design of such a GRSC with a special emphasis on three aspects; (1) uncertainty of waste collection levels, (2) associated carbon emissions, and (3) challenges posed by the supply chain's global aspect, particularly the maritime transportation costs and currency exchange rates. To the best of our knowledge, this paper is the first attempt to integrate the three above-mentioned important aspects in the design of a GRSC. We have used mixed integer-linear programming method along with robust optimization to develop the model which is validated using a sample case study of e-waste management. Our results show that using a robust model by taking the complex interactions characterizing global reverse supply chain networks into account, we can create a better GRSC. The effect of uncertainties and carbon constraints on decisions to reduce costs and emissions are also shown.

  13. 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

  14. 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...

  15. 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.

  16. Wideband 2-D Array Design Optimization With Fabrication Constraints for 3-D US Imaging.

    PubMed

    Roux, Emmanuel; Ramalli, Alessandro; Liebgott, Herve; Cachard, Christian; Robini, Marc C; Tortoli, Piero

    2017-01-01

    Ultrasound (US) 2-D arrays are of increasing interest due to their electronic steering capability to investigate 3-D regions without requiring any probe movement. These arrays are typically populated by thousands of elements that, ideally, should be individually driven by the companion scanner. Since this is not convenient, the so-called microbeamforming methods, yielding a prebeamforming stage performed in the probe handle by suitable custom integrated circuits, have so far been implemented in a few commercial high-end scanners. A possible approach to implement relatively cheap and efficient 3-D US imaging systems is using 2-D sparse arrays in which a limited number of elements can be coupled to an equal number of independent transmit/receive channels. In order to obtain US beams with adequate characteristics all over the investigated volume, the layout of such arrays must be carefully designed. This paper provides guidelines to design, by using simulated annealing optimization, 2-D sparse arrays capable of fitting specific applications or fabrication/implementation constraints. In particular, an original energy function based on multidepth 3-D analysis of the beam pattern is also exploited. A tutorial example is given, addressed to find the N e elements that should be activated in a 2-D fully populated array to yield efficient acoustic radiating performance over the entire volume. The proposed method is applied to a 32 ×32 array centered at 3 MHz to select the 128, 192, and 256 elements that provide the best acoustic performance. It is shown that the 256-element optimized array yields sidelobe levels even lower (by 5.7 dB) than that of the reference 716-element circular and (by 10.3 dB) than that of the reference 1024-element array.

  17. 13 CFR 108.1940 - Procedures for designation of additional Low-Income Geographic Areas

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...) 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...

  18. Expanding the Design Space: Forging the Transition from 3D Printing to Additive Manufacturing

    NASA Astrophysics Data System (ADS)

    Amend, Matthew

    The synergy of Additive Manufacturing and Computational Geometry has the potential to radically expand the "design space" of solutions available to designers. Additive Manufacturing (AM) is capable of fabricating objects that are highly complex both in geometry and material properties. However, the introduction of any new technology can have a disruptive effect on established design practices and organizations. Before "Design for Additive Manufacturing" (DFAM) is a commonplace means of producing objects employed in "real world" products, appropriate design knowledge must be sufficiently integrated within industry. First, materials suited to additive manufacturing methods must be developed to satisfy existing industry standards and specifications, or new standards must be developed. Second, a new class of design representation (CAD) tools will need to be developed. Third, designers and design organizations will need to develop strategies for employing such tools. This thesis describes three DFAM exercises intended to demonstrate the potential for innovative design when using advanced additive materials, tools, and printers. These design exercises included 1) a light-weight composite layup mold developed with topology optimization, 2) a low-pressure fluid duct enhanced with an external lattice structure, and 3) an airline seat tray designed using a non-uniform lattice structure optimized with topology optimization.

  19. Temperature, pressure, and electrochemical constraints on protein speciation: Group additivity calculation of the standard molal thermodynamic properties of ionized unfolded proteins

    NASA Astrophysics Data System (ADS)

    Dick, J. M.; Larowe, D. E.; Helgeson, H. C.

    2006-07-01

    Thermodynamic calculations can be used to quantify environmental constraints on the speciation of proteins, such as the pH and temperature dependence of ionization state, and the relative chemical stabilities of proteins in different biogeochemical settings. These calculations depend in part on values of the standard molal Gibbs energies of proteins and their ionization reactions as a function of temperature and pressure. Because these values are not generally available, we calculated values of the standard molal thermodynamic properties at 25°C and 1 bar as well as the revised Helgeson-Kirkham-Flowers equations of state parameters of neutral and charged zwitterionic reference model compounds including aqueous amino acids, polypeptides, and unfolded proteins. The experimental calorimetric and volumetric data for these species taken from the literature were combined with group additivity algorithms to calculate the properties and parameters of neutral and ionized sidechain and backbone groups in unfolded proteins. The resulting set of group contributions enables the calculation of the standard molal Gibbs energy, enthalpy, entropy, isobaric heat capacity, volume, and isothermal compressibility of unfolded proteins in a range of proton ionization states to temperatures and pressures exceeding 100°C and 1000 bar. This approach provides a useful frame of reference for thermodynamic studies of protein folding and complexation reactions. It can also be used to assign provisional values of the net charge and Gibbs energy of ionized proteins as a function of temperature and pH. Using these values, an Eh-pH diagram for a reaction representing the speciation of extracellular proteins from Pyrococcus furiosus and Bacillus subtilis was generated. The predicted predominance limits of these proteins correspond with the different electrochemical conditions of hydrothermal vents and soils. More comprehensive calculations of this kind may reveal pervasive chemical potential

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

    PubMed

    Moreira, X; Zas, R; Sampedro, L

    2013-05-01

    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.

  1. Shoestring Evaluation: Designing Impact Evaluations under Budget, Time and Data Constraints

    ERIC Educational Resources Information Center

    Bamberger, Michael; Rugh, Jim; Church, Mary; Fort, Lucia

    2004-01-01

    The paper discusses two common scenarios in which evaluators must conduct impact evaluations when working under budget, time, or data constraints. Under the first scenario the evaluator is not called in until the project is already well advanced, and there is a tight deadline for completing the evaluation, frequently combined with a limited budget…

  2. 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

    ... designate a class of employees from the Rocky Flats Plant in Golden, Colorado, as an addition to the Special... subcontractors who worked at the Rocky Flats Plant in Golden, Colorado, from April 1, 1952, through December...

  3. 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...

  4. 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... their contractors and subcontractors who worked in any area at Sandia National Laboratories...

  5. 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 the Clinton Engineer Works in Oak Ridge, Tennessee, as an addition to... Carbon Chemicals Corporation (1947-1949) who were employed at the Clinton Engineer Works in Oak...

  6. Strengthening the Regression Discontinuity Design Using Additional Design Elements: A Within-Study Comparison

    ERIC Educational Resources Information Center

    Wing, Coady; Cook, Thomas D.

    2013-01-01

    The sharp regression discontinuity design (RDD) has three key weaknesses compared to the randomized clinical trial (RCT). It has lower statistical power, it is more dependent on statistical modeling assumptions, and its treatment effect estimates are limited to the narrow subpopulation of cases immediately around the cutoff, which is rarely of…

  7. 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...

  8. 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... 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...

  9. 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

    ... designate a class of employees from the Sandia National Laboratories-Livermore in Livermore, California, as 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...

  10. Isolating wetland CH4 emissions using the additional constraints of δ13CH4, and C2H6 in a inverse modeling framework

    NASA Astrophysics Data System (ADS)

    Guillermo Nuñez Ramirez, Tonatiuh; Marshall, Julia; Houweling, Sander; Dlugokencky, Edward J.; Worthy, Douglas E. J.; Vaughn, Bruce; Simpson, Isobel; White, James; Brand, Willi A.; Sasakawa, Motoki; Nichol, Silvia; Ramonet, Michel; Tyler, Stanley C.; Hueber, Jacques; Helmig, Detlev; Read, Katie; Punjabi, Schalini; Vanni Gatti, Luciana; Krummel, Paul; Heimann, Martin

    2015-04-01

    Wetlands are the largest single source of atmospheric methane (CH_4). However, estimates of their relative contribution to the atmospheric CH4 budget are highly uncertain. Models of CH4 fluxes from wetlands, which reflect our understanding of the processes driving these fluxes, disagree strongly in their estimates of the total contribution of wetlands to the CH4 budget and in the variability of the fluxes in space and time. Atmospheric CH4 observations can provide a top-down constraint on wetland CH4 flux estimates. Results from atmospheric inverse modeling studies highlight the importance of tropical wetlands in driving interannual variability of atmospheric CH_4. Nevertheless, atmospheric observations in the tropics are scarce, with large areas of strong emissions not covered by the atmospheric observation network. Furthermore, the Bayesian framework, often used in atmospheric inverse modeling, preferentially projects signals onto spatiotemporal regions with large a-priori uncertainty, which is the case of tropical wetlands. Since a large lack of knowledge exists as well for other non-wetland sources of atmospheric CH_4, signals from these could be wrongly allocated to tropical wetlands. The CH4 stable carbon isotope signal (δ13CH_4) and co-emitted species such as ethane (C_2H_6) can provide additional constraints which may be use to discriminate wetland from non-wetland CH4 emissions. We describe the set-up of an inverse modeling framework based on the Jena Inversion System and the TM3 transport model that optimizes CH4 fluxes to fit the observed atmospheric CH_4, δ13CH_4, and C_2H6 signals. The fluxes are optimized with the constraint that each source process was assigned a characteristic range of δ13CH4 signals and methane-to-ethane ratios (MERs). An additional characteristic of our set-up is that no seasonal or interannual variability was included in the wetland a-priori estimate to ensure that all variability is derived exclusively from observations. A

  11. 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.

  12. Proportional navigation law design of plane-symmetrical vehicle with terminal attack angle constraint for over target flight

    NASA Astrophysics Data System (ADS)

    Wu, Bin; Ji, Denggao; Guo, Zhenxi; Shen, Haibin; Zhang, Jianfei

    2016-11-01

    This article proposes a type of proportional navigation law design of plane-symmetrical vehicle with terminal attack angle constraint for over target flight. Firstly, the line of sight rotating rate and the velocity rotating rate model of the vehicle are expressed. Then, the attitude of the vehicle is constructed by the acceleration vector requirement of proportional navigation law. Accordingly, the guidance command uncertain issue can be avoided for plane-symmetrical vehicle over target flight. It guarantees high precision to hit the target. The effect and efficiency of the guidance law are shown by simulations of characteristic trajectories.

  13. Assessment of additive/nonadditive effects in structure-activity relationships: implications for iterative drug design.

    PubMed

    Patel, Yogendra; Gillet, Valerie J; Howe, Trevor; Pastor, Joaquin; Oyarzabal, Julen; Willett, Peter

    2008-12-11

    Free-Wilson (FW) analysis is common practice in medicinal chemistry and is based on the assumption that the contributions to activity made by substituents at different substitution positions are additive. We analyze eight near complete combinatorial libraries assayed on several different biological response(s) (GPCR, ion channel, kinase and P450 targets) and show that only half-exhibit clear additive behavior, which leads us to question the concept of additivity that is widely taken for granted in drug discovery. Next, we report a series of retrospective experiments in which subsets are extracted from the libraries for FW analysis to determine the minimum attributes (size, distribution of substituents, and activity range) necessary to reach the same conclusion about additive/nonadditive effects. These attributes can provide guidelines on when it is appropriate to apply FW analysis as well as for library design, and they also have important implications for further steps in iterative drug design.

  14. Rationally designed multifunctional supramolecular iminium catalysis: direct vinylogous Michael addition of unmodified linear dienol substrates.

    PubMed

    Gu, Yun; Wang, Yao; Yu, Tian-Yang; Liang, Yong-Min; Xu, Peng-Fei

    2014-12-15

    The development of a direct vinylogous Michael addition of linear nucleophilic substrates is a long-standing challenge because of the poor reactivity and the considerable difficulty in controlling regioselectivity. By employing a rationally designed multifunctional supramolecular iminium catalysis strategy, the first direct vinylogous Michael addition of unmodified linear substrates to α,β-unsaturated aldehydes, to afford chiral 1,7-dioxo compounds with good yields and excellent regio- as well as enantioselectivity, has been developed.

  15. 77 FR 40948 - Additional Designation of Persons Whose Property and Interests in Property Are Blocked Pursuant...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-11

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE TREASURY Office of Foreign Assets Control Additional Designation of Persons Whose Property and Interests in... security situation and the persistence of violence in Somalia and acts of piracy and armed robbery at...

  16. 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

    ... Visual Flight Rules (VFR) Under the Special Class (JAR-VLA) Regulations; AQUILA Aviation by Excellence... visual flight rules (VFR) expansion and substantiation for the ] Aquila GmbH AT01. These additional... Airworthiness Design Standards: Night visual flight rules (VFR) Under the Special Class (JAR-VLA) Regulations...

  17. 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

    ...). ACTION: Notice. SUMMARY: HHS gives notice of a decision to designate a class of employees from the Oak Ridge National Laboratory (X-10) in Oak Ridge, Tennessee, as an addition to the Special Exposure Cohort... who worked in any area at the Oak Ridge National Laboratory (X-10) in Oak Ridge, Tennessee, from...

  18. Design and development of a layer-based additive manufacturing process for the realization of metal parts of designed mesostructure

    NASA Astrophysics Data System (ADS)

    Williams, Christopher Bryant

    Low-density cellular materials, metallic bodies with gaseous voids, are a unique class of materials that are characterized by their high strength, low mass, good energy absorption characteristics, and good thermal and acoustic insulation properties. In an effort to take advantage of this entire suite of positive mechanical traits, designers are tailoring the cellular mesostructure for multiple design objectives. Unfortunately, existing cellular material manufacturing technologies limit the design space as they are limited to certain part mesostructure, material type, and macrostructure. The opportunity that exists to improve the design of existing products, and the ability to reap the benefits of cellular materials in new applications is the driving force behind this research. As such, the primary research goal of this work is to design, embody, and analyze a manufacturing process that provides a designer the ability to specify the material type, material composition, void morphology, and mesostructure topology for any conceivable part geometry. The accomplishment of this goal is achieved in three phases of research: (1) Design---Following a systematic design process and a rigorous selection exercise, a layer-based additive manufacturing process is designed that is capable of meeting the unique requirements of fabricating cellular material geometry. Specifically, metal parts of designed mesostructure are fabricated via three-dimensional printing of metal oxide ceramic powder followed by post-processing in a reducing atmosphere. (2) Embodiment ---The primary research hypothesis is verified through the use of the designed manufacturing process chain to successfully realize metal parts of designed mesostructure. (3) Modeling & Evaluation ---The designed manufacturing process is modeled in this final research phase so as to increase understanding of experimental results and to establish a foundation for future analytical modeling research. In addition to an analysis of

  19. 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)

  20. Design, methodology, and baseline data of the Personalized Addition Lenses Clinical Trial (PACT)

    PubMed Central

    Yu, Xinping; Zhang, Binjun; Bao, Jinhua; Zhang, Junxiao; Wu, Ge; Xu, Jinling; Zheng, Jingwei; Drobe, Björn; Chen, Hao

    2017-01-01

    Abstract Background: The aim of this study was to describe the design, methods, and baseline characteristics of children enrolled in the Personalized Addition lenses Clinical Trial (PACT). PACT aims to test the myopia control efficacy of progressive addition lenses (PALs) with personalized addition values compared with standard (+2.00 D) addition PALs and single vision lenses (SVLs). Methods: PACT is a randomized, controlled, double-masked clinical trial. Two hundred eleven myopic Chinese children (7–12 years) were enrolled and randomized into 1 of the 3 following groups: personalized addition PALs; +2.00 addition PALs; and SVLs. Personalized addition values were determined based on the highest addition that satisfied Sheard criterion. Axial length and other biometric data were also recorded. Results: At baseline, no differences were found between the right and left eyes for any of the main parameters. The enrolled children were 9.7 ± 1.1 years’ old with cycloplegic autorefraction (right eye [OD]: −2.36 ± 0.64 D), near phoria (1.0 ± 5.0 prism diopter esophoria), lag of accommodation (1.40 ± 0.50 D) and axial length (OD: 24.58 ± 0.74 mm). The personalized addition values ranged from +0.75 to +3.00 (average ± SD: 2.19 ± 0.73 D). Conclusion: PACT is a clinical trial evaluating whether myopia progression in children can be slowed by wearing personalized addition PALs compared with fixed addition PALs and SVLs as measured by cycloplegic autorefraction and axial length. Baseline data were comparable with those of previous myopia control studies in children. Subjects will be followed up every 6 months for 2 years. PMID:28296722

  1. 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.

  2. Design of Distributed Controllers Seeking Optimal Power Flow Solutions Under Communication Constraints

    SciTech Connect

    Dall'Anese, Emiliano; Simonetto, Andrea; Dhople, Sairaj

    2016-12-29

    This paper focuses on power distribution networks featuring inverter-interfaced distributed energy resources (DERs), and develops feedback controllers that drive the DER output powers to solutions of time-varying AC optimal power flow (OPF) problems. Control synthesis is grounded on primal-dual-type methods for regularized Lagrangian functions, as well as linear approximations of the AC power-flow equations. Convergence and OPF-solution-tracking capabilities are established while acknowledging: i) communication-packet losses, and ii) partial updates of control signals. The latter case is particularly relevant since it enables asynchronous operation of the controllers where DER setpoints are updated at a fast time scale based on local voltage measurements, and information on the network state is utilized if and when available, based on communication constraints. As an application, the paper considers distribution systems with high photovoltaic integration, and demonstrates that the proposed framework provides fast voltage-regulation capabilities, while enabling the near real-time pursuit of solutions of AC OPF problems.

  3. Design of Distributed Controllers Seeking Optimal Power Flow Solutions under Communication Constraints: Preprint

    SciTech Connect

    Dall'Anese, Emiliano; Simonetto, Andrea; Dhople, Sairaj

    2016-12-01

    This paper focuses on power distribution networks featuring inverter-interfaced distributed energy resources (DERs), and develops feedback controllers that drive the DER output powers to solutions of time-varying AC optimal power flow (OPF) problems. Control synthesis is grounded on primal-dual-type methods for regularized Lagrangian functions, as well as linear approximations of the AC power-flow equations. Convergence and OPF-solution-tracking capabilities are established while acknowledging: i) communication-packet losses, and ii) partial updates of control signals. The latter case is particularly relevant since it enables asynchronous operation of the controllers where DER setpoints are updated at a fast time scale based on local voltage measurements, and information on the network state is utilized if and when available, based on communication constraints. As an application, the paper considers distribution systems with high photovoltaic integration, and demonstrates that the proposed framework provides fast voltage-regulation capabilities, while enabling the near real-time pursuit of solutions of AC OPF problems.

  4. 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.

  5. Design, Development and Hotfire Testing of Monolithic Copper and Bimetallic Additively Manufactured Combustion Chambers

    NASA Technical Reports Server (NTRS)

    Gradl, Paul; Barnett, Greg; Brandsmeier, Will; Greene, Sandy Elam; Protz, Chris

    2016-01-01

    NASA and industry partners are working towards fabrication process development to reduce costs and schedules associated with manufacturing liquid rocket engine components with the goal of reducing overall mission costs. One such technique being evaluated is powder-bed fusion or selective laser melting (SLM) otherwise commonly referred to as additive manufacturing. The NASA Low Cost Upper Stage Propulsion (LCUSP) program was designed to develop processes and material characterization for the GRCop-84 copper-alloy commensurate with powder bed additive manufacturing, evaluate bimetallic deposition and complete testing of a full scale combustion chamber. As part of this development, the process has been transferred to industry partners to enable a long-term supply chain of monolithic copper combustion chambers. As a direct spin off of this program, NASA is working with industry partners to further develop the printing process for the GRCop-84 material in addition to the C-18150 (CuCrZr) material. To advance the process further and allow for optimization with multiple materials, NASA is also investigating the feasibility of bimetallic additively manufactured chambers. A 1.2k sized thrust-chamber was designed and developed to compare the printing process of the GRCop-84 and C-18150 SLM materials. A series of similar MCC liners also completed development with an Inconel 625 jacket bonded to the GRcop-84 liner evaluating direct metal deposition (DMD) laser and arc-based techniques. This paper describes the design, development, manufacturing and testing of these combustion chambers and associated lessons learned throughout the design and development process.

  6. The effect of alkaline additives on the performance of surfactant systems designed to recover light oils

    SciTech Connect

    French, T.R.; Josephson, C.B.; Evans, D.B.

    1991-02-01

    Surfactant flooding is flexible because of the ability to optimize formulations for a wide range of reservoir conditions and crude oil types. The objective for this work was to determine if the addition of alkaline additives will allow the design of surfactant formulations that are effective for the recovery of crude oil, while, at the same time, maintaining the surfactant concentration at a much lower level than has previously been used for micellar flooding. Specifically, the focus of the work was on light, midcontinent crudes that typically have very low acid contents. These oils are typical of much of the midcontinent resource. The positive effect of alkaline additives on the phase behavior of the surfactant formulations and acidic crude oils is well known. The extension to nonacidic and slightly acidic oils is not obvious. Three crude oils, a variety of commercial surfactants, and several alkaline additives were tested. The oils had acid numbers that ranged from 0.13, which is quite low, to less than 0.01 mg KOH/g of oil. Alkaline additives were found to be very effective in recovering Delaware-Childers (OK) oil at elevated temperatures, but much less effective at reservoir temperatures. Alkaline additives were very effective with Teapot Dome (WY) oil. With Teapot Dome oil, surfactant/alkali systems produced ultralow IFT values and recovered 60% of the residual oil that remained after waterflooding. The effect of alkaline additives on recovering Hepler (KS) oil was minimal. The results of this work indicate that alkaline additives do have merit for use in surfactant flooding of low acid crude oils; however, no universal statement about applicability can be made. Each oil behaves differently, with this treatment, and the effect of alkaline additives must be determined (at reservoir conditions) for each oil. 23 refs., 13 figs., 3 tabs.

  7. Numerical Method for the Design of Healing Chamber in Additive-Manufactured Dental Implants.

    PubMed

    Lee, Hsiao-Chien; Tsai, Pei-I; Huang, Chih-Chieh; Chen, San-Yuan; Chao, Chuen-Guang; Tsou, Nien-Ti

    2017-01-01

    The inclusion of a healing chamber in dental implants has been shown to promote biological healing. In this paper, a novel numerical approach to the design of the healing chamber for additive-manufactured dental implants is proposed. This study developed an algorithm for the modeling of bone growth and employed finite element method in ANSYS to facilitate the design of healing chambers with a highly complex configuration. The model was then applied to the design of dental implants for insertion into the posterior maxillary bones. Two types of ITI® solid cylindrical screwed implant with extra rectangular-shaped healing chamber as an initial design are adopted, with which to evaluate the proposed system. This resulted in several configurations for the healing chamber, which were then evaluated based on the corresponding volume fraction of healthy surrounding bone. The best of these implants resulted in a healing chamber surrounded by around 9.2% more healthy bone than that obtained from the original design. The optimal design increased the contact area between the bone and implant by around 52.9%, which is expected to have a significant effect on osseointegration. The proposed approach is highly efficient which typically completes the optimization of each implant within 3-5 days on an ordinary personal computer. It is also sufficiently general to permit extension to various loading conditions.

  8. Numerical Method for the Design of Healing Chamber in Additive-Manufactured Dental Implants

    PubMed Central

    Lee, Hsiao-Chien; Tsai, Pei-I; Huang, Chih-Chieh; Chen, San-Yuan; Chao, Chuen-Guang

    2017-01-01

    The inclusion of a healing chamber in dental implants has been shown to promote biological healing. In this paper, a novel numerical approach to the design of the healing chamber for additive-manufactured dental implants is proposed. This study developed an algorithm for the modeling of bone growth and employed finite element method in ANSYS to facilitate the design of healing chambers with a highly complex configuration. The model was then applied to the design of dental implants for insertion into the posterior maxillary bones. Two types of ITI® solid cylindrical screwed implant with extra rectangular-shaped healing chamber as an initial design are adopted, with which to evaluate the proposed system. This resulted in several configurations for the healing chamber, which were then evaluated based on the corresponding volume fraction of healthy surrounding bone. The best of these implants resulted in a healing chamber surrounded by around 9.2% more healthy bone than that obtained from the original design. The optimal design increased the contact area between the bone and implant by around 52.9%, which is expected to have a significant effect on osseointegration. The proposed approach is highly efficient which typically completes the optimization of each implant within 3–5 days on an ordinary personal computer. It is also sufficiently general to permit extension to various loading conditions. PMID:28293628

  9. 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.

  10. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    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.

  12. 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...

  13. 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…

  14. 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.

  15. A generalized sizing method for revolutionary concepts under probabilistic design constraints

    NASA Astrophysics Data System (ADS)

    Nam, Taewoo

    Internal combustion (IC) engines that consume hydrocarbon fuels have dominated the propulsion systems of air-vehicles for the first century of aviation. In recent years, however, growing concern over rapid climate changes and national energy security has galvanized the aerospace community into delving into new alternatives that could challenge the dominance of the IC engine. Nevertheless, traditional aircraft sizing methods have significant shortcomings for the design of such unconventionally powered aircraft. First, the methods are specialized for aircraft powered by IC engines, and thus are not flexible enough to assess revolutionary propulsion concepts that produce propulsive thrust through a completely different energy conversion process. Another deficiency associated with the traditional methods is that a user of these methods must rely heavily on experts' experience and advice for determining appropriate design margins. However, the introduction of revolutionary propulsion systems and energy sources is very likely to entail an unconventional aircraft configuration, which inexorably disqualifies the conjecture of such "connoisseurs" as a means of risk management. Motivated by such deficiencies, this dissertation aims at advancing two aspects of aircraft sizing: (1) to develop a generalized aircraft sizing formulation applicable to a wide range of unconventionally powered aircraft concepts and (2) to formulate a probabilistic optimization technique that is able to quantify appropriate design margins that are tailored towards the level of risk deemed acceptable to a decision maker. A more generalized aircraft sizing formulation, named the Architecture Independent Aircraft Sizing Method (AIASM), was developed for sizing revolutionary aircraft powered by alternative energy sources by modifying several assumptions of the traditional aircraft sizing method. Along with advances in deterministic aircraft sizing, a non-deterministic sizing technique, named the

  16. 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.

  17. A Novel Multiscale Design of Interfaces for Polymeric Composites and Bonded Joints using Additive Manufacturing

    DTIC Science & Technology

    2016-09-13

    AFRL-AFOSR-VA-TR-2016-0317 A Novel Multiscale Design of Interfaces for Polymeric Composites and Bonded Joints using Additive Manufacturing Pavana...PROGRAM ELEMENT NUMBER 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 6. AUTHOR(S) 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8...PERFORMING ORGANIZATION REPORT NUMBER 10. SPONSOR/MONITOR’S ACRONYM(S) 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 9. SPONSORING/MONITORING AGENCY NAME(S) AND

  18. Constraints on LISA Pathfinder’s self-gravity: design requirements, estimates and testing procedures

    NASA Astrophysics Data System (ADS)

    Armano, M.; Audley, H.; Auger, G.; Baird, J.; Binetruy, P.; Born, M.; Bortoluzzi, D.; Brandt, N.; Bursi, A.; Caleno, M.; Cavalleri, A.; Cesarini, A.; Cruise, M.; Danzmann, K.; de Deus Silva, M.; Desiderio, D.; Piersanti, E.; Diepholz, I.; Dolesi, R.; Dunbar, N.; Ferraioli, L.; Ferroni, V.; Fitzsimons, E.; Flatscher, R.; Freschi, M.; Gallegos, J.; García Marirrodriga, C.; Gerndt, R.; Gesa, L.; Gibert, F.; Giardini, D.; Giusteri, R.; Grimani, C.; Grzymisch, J.; Harrison, I.; Heinzel, G.; Hewitson, M.; Hollington, D.; Hueller, M.; Huesler, J.; Inchauspé, H.; Jennrich, O.; Jetzer, P.; Johlander, B.; Karnesis, N.; Kaune, B.; Korsakova, N.; Killow, C.; Lloro, I.; Liu, L.; López-Zaragoza, J. P.; Maarschalkerweerd, R.; Madden, S.; Mance, D.; Martín, V.; Martin-Polo, L.; Martino, J.; Martin-Porqueras, F.; Mateos, I.; McNamara, P. W.; Mendes, J.; Mendes, L.; Moroni, A.; Nofrarias, M.; Paczkowski, S.; Perreur-Lloyd, M.; Petiteau, A.; Pivato, P.; Plagnol, E.; Prat, P.; Ragnit, U.; Ramos-Castro, J.; Reiche, J.; Romera Perez, J. A.; Robertson, D.; Rozemeijer, H.; Rivas, F.; Russano, G.; Sarra, P.; Schleicher, A.; Slutsky, J.; Sopuerta, C. F.; Sumner, T.; Texier, D.; Thorpe, J. I.; Tomlinson, R.; Trenkel, C.; Vetrugno, D.; Vitale, S.; Wanner, G.; Ward, H.; Warren, C.; Wass, P. J.; Wealthy, D.; Weber, W. J.; Wittchen, A.; Zanoni, C.; Ziegler, T.; Zweifel, P.

    2016-12-01

    LISA Pathfinder satellite was launched on 3 December 2015 toward the Sun-Earth first Lagrangian point (L1) where the LISA Technology Package (LTP), which is the main science payload, will be tested. LTP achieves measurements of differential acceleration of free-falling test masses (TMs) with sensitivity below 3× {10}-14 {{m}} {{{s}}}-2 {{Hz}}-1/2 within the 1-30 mHz frequency band in one-dimension. The spacecraft itself is responsible for the dominant differential gravitational field acting on the two TMs. Such a force interaction could contribute a significant amount of noise and thus threaten the achievement of the targeted free-fall level. We prevented this by balancing the gravitational forces to the sub nm s-2 level, guided by a protocol based on measurements of the position and the mass of all parts that constitute the satellite, via finite element calculation tool estimates. In this paper, we will introduce the gravitational balance requirements and design, and then discuss our predictions for the balance that will be achieved in flight.

  19. The High Cadence Transient Survey (HITS). I. Survey Design and Supernova Shock Breakout Constraints

    NASA Astrophysics Data System (ADS)

    Förster, F.; Maureira, J. C.; San Martín, J.; Hamuy, M.; Martínez, J.; Huijse, P.; Cabrera, G.; Galbany, L.; de Jaeger, Th.; González–Gaitán, S.; Anderson, J. P.; Kunkarayakti, H.; Pignata, G.; Bufano, F.; Littín, J.; Olivares, F.; Medina, G.; Smith, R. C.; Vivas, A. K.; Estévez, P. A.; Muñoz, R.; Vera, E.

    2016-12-01

    We present the first results of the High Cadence Transient Survey (HiTS), a survey for which the objective is to detect and follow-up optical transients with characteristic timescales from hours to days, especially the earliest hours of supernova (SN) explosions. HiTS uses the Dark Energy Camera and a custom pipeline for image subtraction, candidate filtering and candidate visualization, which runs in real-time to be able to react rapidly to the new transients. We discuss the survey design, the technical challenges associated with the real-time analysis of these large volumes of data and our first results. In our 2013, 2014, and 2015 campaigns, we detected more than 120 young SN candidates, but we did not find a clear signature from the short-lived SN shock breakouts (SBOs) originating after the core collapse of red supergiant stars, which was the initial science aim of this survey. Using the empirical distribution of limiting magnitudes from our observational campaigns, we measured the expected recovery fraction of randomly injected SN light curves, which included SBO optical peaks produced with models from Tominaga et al. (2011) and Nakar & Sari (2010). From this analysis, we cannot rule out the models from Tominaga et al. (2011) under any reasonable distributions of progenitor masses, but we can marginally rule out the brighter and longer-lived SBO models from Nakar & Sari (2010) under our best-guess distribution of progenitor masses. Finally, we highlight the implications of this work for future massive data sets produced by astronomical observatories, such as LSST.

  20. Design and tuning of standard additive model based fuzzy PID controllers for multivariable process systems.

    PubMed

    Harinath, Eranda; Mann, George K I

    2008-06-01

    This paper describes a design and two-level tuning method for fuzzy proportional-integral derivative (FPID) controllers for a multivariable process where the fuzzy inference uses the inference of standard additive model. The proposed method can be used for any n x n multi-input-multi-output process and guarantees closed-loop stability. In the two-level tuning scheme, the tuning follows two steps: low-level tuning followed by high-level tuning. The low-level tuning adjusts apparent linear gains, whereas the high-level tuning changes the nonlinearity in the normalized fuzzy output. In this paper, two types of FPID configurations are considered, and their performances are evaluated by using a real-time multizone temperature control problem having a 3 x 3 process system.

  1. Half a degree additional warming, prognosis and projected impacts (HAPPI): background and experimental design

    NASA Astrophysics Data System (ADS)

    Mitchell, Daniel; AchutaRao, Krishna; Allen, Myles; Bethke, Ingo; Beyerle, Urs; Ciavarella, Andrew; Forster, Piers M.; Fuglestvedt, Jan; Gillett, Nathan; Haustein, Karsten; Ingram, William; Iversen, Trond; Kharin, Viatcheslav; Klingaman, Nicholas; Massey, Neil; Fischer, Erich; Schleussner, Carl-Friedrich; Scinocca, John; Seland, Øyvind; Shiogama, Hideo; Shuckburgh, Emily; Sparrow, Sarah; Stone, Dáithí; Uhe, Peter; Wallom, David; Wehner, Michael; Zaaboul, Rashyd

    2017-02-01

    The Intergovernmental Panel on Climate Change (IPCC) has accepted the invitation from the UNFCCC to provide a special report on the impacts of global warming of 1.5 °C above pre-industrial levels and on related global greenhouse-gas emission pathways. Many current experiments in, for example, the Coupled Model Inter-comparison Project (CMIP), are not specifically designed for informing this report. Here, we document the design of the half a degree additional warming, projections, prognosis and impacts (HAPPI) experiment. HAPPI provides a framework for the generation of climate data describing how the climate, and in particular extreme weather, might differ from the present day in worlds that are 1.5 and 2.0 °C warmer than pre-industrial conditions. Output from participating climate models includes variables frequently used by a range of impact models. The key challenge is to separate the impact of an additional approximately half degree of warming from uncertainty in climate model responses and internal climate variability that dominate CMIP-style experiments under low-emission scenarios.Large ensembles of simulations (> 50 members) of atmosphere-only models for three time slices are proposed, each a decade in length: the first being the most recent observed 10-year period (2006-2015), the second two being estimates of a similar decade but under 1.5 and 2 °C conditions a century in the future. We use the representative concentration pathway 2.6 (RCP2.6) to provide the model boundary conditions for the 1.5 °C scenario, and a weighted combination of RCP2.6 and RCP4.5 for the 2 °C scenario.

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. Vacuum infusion equipment design and the influence of reinforcement layers addition to the resin infusion time

    NASA Astrophysics Data System (ADS)

    Saputra, A. H.; Setyarso, G.

    2016-11-01

    The characteristic of composite material is greatly influenced by the manufacture method of composite. The conventional method that has been used such as hand lay-up and spray up are simple and easy to apply but the composite tend to have a void in it because of the air trapped during the manufacture process. Vacuum infusion is one of the modern composite manufacture process which can replace the conventional method. The problem of this method happens when the resin infusion time become longer due to the addition of reinforcement layers. When the resin infusion time is longer than the resin's gel time, the resin will become gel and not able to flow into the mold. In order to overcome this problem, a study that observe the influence of reinforcement layers addition to the resin infusion time is needed. In this study, vacuum infusion equipment for composite materials manufacturing process that are designed consists of: 1×1m glass as the mold, 1L PVC tube for the resin container, 1L glass tube for the resin trap, and ‘A HP vacuum pump with 7 CFM vacuum speed. The resin that is used in this study is unsaturated polyester resin (UPR) and the fiber used as reinforcement is fiber glass. It is observed that the more number of reinforcement layers the longer resin infusion time will be. The resin infusion time (in seconds) from two until six layers respectively for the area of 15×20cm are: 88, 115, 145, 174, 196; for the area of 15×25cm are: 119, 142, 168, 198, 235; and for the area of 15×35cm are: 181, 203, 235, 263, 303. The maximum reinforcement layers that can be accommodated for each 15×20cm, 15×25cm, and 15×35cm area are respectively 31 layers, 29 layers, and 25 layers.

  7. 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.

  8. 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

  9. An introduction to modeling longitudinal data with generalized additive models: applications to single-case designs.

    PubMed

    Sullivan, Kristynn J; Shadish, William R; Steiner, Peter M

    2015-03-01

    Single-case designs (SCDs) are short time series that assess intervention effects by measuring units repeatedly over time in both the presence and absence of treatment. This article introduces a statistical technique for analyzing SCD data that has not been much used in psychological and educational research: generalized additive models (GAMs). In parametric regression, the researcher must choose a functional form to impose on the data, for example, that trend over time is linear. GAMs reverse this process by letting the data inform the choice of functional form. In this article we review the problem that trend poses in SCDs, discuss how current SCD analytic methods approach trend, describe GAMs as a possible solution, suggest a GAM model testing procedure for examining the presence of trend in SCDs, present a small simulation to show the statistical properties of GAMs, and illustrate the procedure on 3 examples of different lengths. Results suggest that GAMs may be very useful both as a form of sensitivity analysis for checking the plausibility of assumptions about trend and as a primary data analysis strategy for testing treatment effects. We conclude with a discussion of some problems with GAMs and some future directions for research on the application of GAMs to SCDs.

  10. Sulfate specifications as a constraint to gypsum addition to cement and possible replacement of gypsum as an additive. Phase I. Final quarterly technical progress report, December 1979-January-February 1980

    SciTech Connect

    Kantro, D.L.

    1980-04-01

    The results obtained during this quarter indicate that, based on x ray diffraction observations, rapid uptake of sulfate can be effected in low C/sub 3/A systems. This uptake is of sulfate accompanying akali and is by the aluminoferrite phase. Expansion studies indicate low expansions by low C/sub 3/A systems. Further reductions in expansion occur with the use of admixtures. The lowest expansions occur in high alkai sulfate containing systems. This result is consistent with the observation of rapid sulfate uptake in such systems. Carbonate addition results indicate that increasing carbonate content decreases rate and extent of outside sulfate attack. With respect to compressive strength, there appears to be an optimum value for carbonate addition to a high akali-high C/sub 3/A clinker. Addition of ground dolomite gives results similar to those for limestone. Use of a high-fineness limestone has a strength-enhancing effect and no adverse effect on flow.

  11. 10 CFR 60.133 - Additional design criteria for the underground facility.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... RADIOACTIVE WASTES IN GEOLOGIC REPOSITORIES Technical Criteria Design Criteria for the Geologic Repository... waste. The underground facility shall be designed to permit retrieval of waste in accordance with the performance objectives of § 60.111. (d) Control of water and gas. The design of the underground facility...

  12. 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 the Y-12 facility in Oak Ridge, Tennessee, as an addition... facility in Oak Ridge, Tennessee, during the period from January 1, 1948 through December 31, 1957, for...

  13. 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...

  14. Minimization of Wave Drag Due to Thickness with Constraints on Constant Volume and Maximum Thickness Position

    NASA Astrophysics Data System (ADS)

    Ishida, Yoji

    We have developed a numerical method for design of minimum-drag supersonic wing thickness with constraints on total volume and wing maximum thickness position. The method is based on the linearized supersonic theory and is an extension of Kawasaki's method which deals only with total volume constraint. The maximum thickness position of the wing, a new constraint condition, is an important information from both aerodynamic and structural point of view. The addition of the constraint has considerably extended the design possibility and has actually produced many interesting optimum thickness families. Numerical examples are given for delta, gothic and arrow wings which confirm the usefulness of present design method.

  15. 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

    ... AGENCY 40 CFR Part 81 Additional Air Quality Designations for the 2006 24-Hour Fine Particle National Ambient Air Quality Standards AGENCY: Environmental Protection Agency (EPA). ACTION: Supplemental... particle (PM 2.5 ) national ambient air quality standards (NAAQS) air quality designations for the...

  16. 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

    ... Safety and Health Final Effect of Designation of a Class of Employees for Addition to the Special... and Human Services (HHS). ACTION: Notice. SUMMARY: HHS gives notice concerning the final effect of the HHS decision to designate a class of employees from BWX Technologies, Inc., in Lynchburg, Virginia,...

  17. 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

    ... 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 HHS decision to designate a class of employees from BWX Technologies, Inc., Lynchburg, Virginia, as an...

  18. 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

    ..., Division of Compensation Analysis and Support, NIOSH, 4676 Columbia Parkway, MS C-46, Cincinnati, OH 45226... U.S.C. 7384q(b), the Secretary of HHS designated the following class of employees as an addition to... Exposure Cohort. This designation became effective on April 5, 2013, as provided for under 42 U.S.C....

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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... Lawrence Berkeley National Laboratory in Berkeley, California, from August 13, 1942 through December...

  5. 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…

  6. 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...

  7. 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

    ... Ames Laboratory at Iowa State University during the period from August 13, 1942 through December 31...). ACTION: Notice. SUMMARY: HHS gives notice of a decision to designate a class of employees from the...

  8. 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

    ...). ACTION: Notice. SUMMARY: HHS gives notice of a decision to designate a class of employees from the Mound... Mound Plant in Miamisburg, Ohio, from September 1, 1972, through December 31, 1972, or from January...

  9. 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

    ...: Notice. SUMMARY: HHS gives notice of a decision to designate a class of employees from the Mound Plant in... worked at the Mound Plant in Miamisburg, Ohio from March 1, 1959 through March 5, 1980, for a number...

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

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... specific site conditions identified through in situ monitoring, testing, or excavation. (c) Retrieval of waste. The underground facility shall be designed to permit retrieval of waste in accordance with...

  11. 10 CFR 60.133 - Additional design criteria for the underground facility.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... specific site conditions identified through in situ monitoring, testing, or excavation. (c) Retrieval of waste. The underground facility shall be designed to permit retrieval of waste in accordance with...

  12. 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 Electro Metallurgical site in Niagara Falls, New York, as an... their contractors and subcontractors who worked at the Electro Metallurgical site in Niagara Falls,...

  13. 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

    ...). ACTION: Notice. SUMMARY: HHS gives notice of a decision to designate a class of employees from Sandia... at the Sandia National Laboratories in Albuquerque, New Mexico, from January 1, 1949 through...

  14. 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

    ...). ACTION: Notice. SUMMARY: HHS gives notice of a decision to designate a class of employees at Westinghouse... Employer employees who worked at Westinghouse Electric Corp., Bloomfield, New Jersey, from August 13,...

  15. 76 FR 3907 - Designation of a Class of Employees for Addition to the Special Exposure Cohort

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-21

    ... Chemicals, Inc., Texas City, Texas, as an addition to the Special Exposure Cohort (SEC) under the Energy... who worked at Texas City Chemicals, Inc., from October 5, 1953, through September 30, 1955, for...

  16. 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...

  17. 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

    ... as the Fernald Environmental Management Project (FEMP), as an addition to the Special Exposure Cohort... Production Center (FMPC) in Fernald, Ohio, also known as the Fernald Environmental Management Project...

  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

    ... facility in Oak Ridge, Tennessee, as an addition to the Special Exposure Cohort (SEC) under the Energy... facility in Oak Ridge, Tennessee, during the period from January 1, 1948 through December 31, 1957, for...

  19. 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...

  20. 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...

  1. 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

  2. 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.

  3. The Design and Implementation of an Expander for the Hierarchical Real- Time Constraints of Computer Aided Prototyping System (CAPS)

    DTIC Science & Technology

    1991-09-01

    PsdlComponent .......................... 41 Figure 4.4 Declaration of type PSDLPROGRAM ......................... 42 Figre 4.5 The Declaration of YYSType...Specification part: Defines the external interfaces of the operator or the type through a series of interface declarations , provides timing constraints, and...computational model containing OPERATORS that communicate via DATA STREAMS. Modularity is supported through the use of independent operators which can

  4. A Framework for Dynamic Constraint Reasoning Using Procedural Constraints

    NASA Technical Reports Server (NTRS)

    Jonsson, Ari K.; Frank, Jeremy D.

    1999-01-01

    Many complex real-world decision and control problems contain an underlying constraint reasoning problem. This is particularly evident in a recently developed approach to planning, where almost all planning decisions are represented by constrained variables. This translates a significant part of the planning problem into a constraint network whose consistency determines the validity of the plan candidate. Since higher-level choices about control actions can add or remove variables and constraints, the underlying constraint network is invariably highly dynamic. Arbitrary domain-dependent constraints may be added to the constraint network and the constraint reasoning mechanism must be able to handle such constraints effectively. Additionally, real problems often require handling constraints over continuous variables. These requirements present a number of significant challenges for a constraint reasoning mechanism. In this paper, we introduce a general framework for handling dynamic constraint networks with real-valued variables, by using procedures to represent and effectively reason about general constraints. The framework is based on a sound theoretical foundation, and can be proven to be sound and complete under well-defined conditions. Furthermore, the framework provides hybrid reasoning capabilities, as alternative solution methods like mathematical programming can be incorporated into the framework, in the form of procedures.

  5. Rational Design of Solution Additives for the Prevention of Protein Aggregation

    PubMed Central

    Baynes, Brian M.; Trout, Bernhardt L.

    2004-01-01

    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 Å radius, an 8 Å 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. PMID:15345542

  6. 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.

  7. 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.

  8. 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.

  9. 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,...

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

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... specific site conditions identified through in situ monitoring, testing, or excavation. (c) Retrieval of... deleterious rock movement or fracturing of overlying or surrounding rock. (f) Rock excavation. The design of the underground facility shall incorporate excavation methods that will limit the potential...

  11. 78 FR 54791 - Proposed Additional Airworthiness Design Standards: Advanced Avionics Under the Special Class...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-06

    ... current regulations only address traditional federated gauges. The European Aviation Safety Agency (EASA... through EASA special conditions or new regulations. These Federal Aviation Administration (FAA) design... overburdensome and to encourage EASA to follow suit. DATES: Comments must be received on or before October...

  12. 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...

  13. 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

    ... Airport Storage Site in St. Louis, Missouri, as an addition to the Special Exposure Cohort (SEC) under the Energy Employees Occupational Illness Compensation Program Act of 2000. On July 14, 2010, the Secretary... Department of Energy, its predecessor agencies, and its contractors and subcontractors who worked in any...

  14. Design of additive quantum codes via the codeword-stabilized framework

    NASA Astrophysics Data System (ADS)

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

    2012-02-01

    Codeword stabilized (CWS) construction defines a quantum code by combining a classical binary code with some underlying graph state. In general, CWS codes are non-additive but become additive stabilizer codes if derived from a linear binary code. Generic CWS codes typically require complex error correction; however, we show that the CWS framework is an efficient tool for constructing good stabilizer codes with simple decoding. We start by proving the lower Gilbert-Varshamov bound on the parameters of an additive CWS code which can be obtained from a given graph. We also show that cyclic additive CWS codes belong to a previously overlooked family of single-generator cyclic stabilizer codes; these codes are derived from a circulant graph and a cyclic binary code. Finally, we present several families of simple stabilizer codes with relatively good parameters, including a family of the smallest toric-like cyclic CWS codes which have length, dimension, and distance as follows: [[t^2+(t+1)^2,1,2t+1

  15. 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...

  16. 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) under the Energy Employees Occupational Illness Compensation Program Act of 2000. On April 5, 2010, the... Department of Energy, its predecessor agencies, and their contractors and subcontractors who worked at...

  17. 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

    ... Soto Avenue Facility in Los Angeles County, California, as an addition to the Special Exposure Cohort (SEC) under the Energy Employees Occupational Illness Compensation Program Act of 2000. On July 14... employees of the Department of Energy, its predecessor agencies, and their contractors and...

  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. 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

    ...HHS gives notice concerning the final effect of the HHS decision to designate a class of employees from Simonds Saw and Steel Co., Lockport, New York, as an addition to the Special Exposure Cohort (SEC) under the Energy Employees Occupational Illness Compensation Program Act of 2000. On January 6, 2011, as provided for under 42 U.S.C. 7384q(b), the Secretary of HHS designated the following......

  20. 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

    ...HHS gives 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) under the Energy Employees Occupational Illness Compensation Program Act of 2000. On May 11, 2012, as provided for under 42 U.S.C. Sec. 7384q(b), the Secretary of HHS designated the......

  1. 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

    ...HHS gives notice concerning the final effect of the HHS decision to designate a class of employees from Texas City Chemicals, Inc., Texas City, Texas, as an addition to the Special Exposure Cohort (SEC) under the Energy Employees Occupational Illness Compensation Program Act of 2000. On January 6, 2011, as provided for under 42 U.S.C. 7384q(b), the Secretary of HHS designated the following......

  2. 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

    ...HHS gives notice concerning the final effect of the HHS decision to designate a class of employees from Vitro Manufacturing in Canonsburg, Pennsylvania, as an addition to the Special Exposure Cohort (SEC) under the Energy Employees Occupational Illness Compensation Program Act of 2000. On October 18, 2011, as provided for under 42 U.S.C. 7384q(b), the Secretary of HHS designated the following......

  3. 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

    ...HHS gives 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) under the Energy Employees Occupational Illness Compensation Program Act of 2000. On May 11, 2012, as provided for under 42 U.S.C. 7384q(b), the Secretary of HHS designated the......

  4. 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

    ...HHS gives notice concerning the final effect of the HHS decision to designate a class of employees from the Sandia National Laboratories, Albuquerque, New Mexico, as an addition to the Special Exposure Cohort (SEC) under the Energy Employees Occupational Illness Compensation Program Act of 2000. On July 29, 2011, as provided for under 42 U.S.C. 7384q(b), the Secretary of HHS designated the......

  5. 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

    ...HHS gives 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 the Energy Employees Occupational Illness Compensation Program Act of 2000. On May 11, 2012, as provided for under 42 U.S.C. 7384q(b), the Secretary of HHS designated the......

  6. 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

    ...HHS gives notice concerning the final effect of the HHS decision to designate a class of employees from the Pantex Plant in Amarillo, Texas, as an addition to the Special Exposure Cohort (SEC) under the Energy Employees Occupational Illness Compensation Program Act of 2000. On December 21, 2011, as provided for under 42 U.S.C. 7384q(b), the Secretary of HHS designated the following class of......

  7. 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.

  8. 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

  9. Additional Drug Resistance Patterns among Multidrug-Resistant Tuberculosis Patients in Korea: Implications for Regimen Design

    PubMed Central

    2017-01-01

    Detailed information on additional drug resistance patterns of multidrug-resistant tuberculosis (MDR-TB) is essential to build an effective treatment regimen; however, such data are scarce in Korea. We retrospectively analyzed the results of phenotypic drug susceptibility testing (DST) of culture confirmed-TB patients from January 2010 to December 2014 in 7 university hospitals in Korea. MDR-TB was identified among 6.8% (n = 378) of 5,599 isolates. A total of 57.1% (n = 216) of the MDR-TB patients had never been treated for TB. Strains from MDR-TB patients showed additional resistance to pyrazinamide (PZA) (35.7%), any second-line injectable drug (19.3%), and any fluoroquinolone (26.2%). Extensively drug resistant TB comprised 12.4% (n = 47) of the MDR-TB patients. Of 378 MDR-TB patients, 50.3% (n = 190) were eligible for the shorter MDR-TB regimen, and 50.0% (n = 189) were fully susceptible to the 5 drugs comprising the standard conventional regimen (PZA, kanamycin, ofloxoacin, prothionamide, and cycloserine). In conclusion, the proportion of new patients and the levels of additional drug resistance were high in MDR-TB patients. Considering the high levels of drug resistance, the shorter MDR-TB treatment regimen may not be feasible; instead, an individually tailored regimen based on the results of molecular and phenotypic DST may be more appropriate in MDR-TB patients in Korea. PMID:28244290

  10. Widespread evidence for non-additive genetic variation in Cloninger's and Eysenck's personality dimensions using a twin plus sibling design.

    PubMed

    Keller, Matthew C; Coventry, William L; Heath, Andrew C; Martin, Nicholas G

    2005-11-01

    Studies using the classical twin design often conclude that most genetic variation underlying personality is additive in nature. However, studies analyzing only twins are very limited in their ability to detect non-additive genetic variation and are unable to detect sources of variation unique to twins, which can mask non-additive genetic variation. The current study assessed 9672 MZ and DZ twin individuals and 3241 of their siblings to investigate the environmental and genetic architecture underlying eight dimensions of personality: four from Eysenck's Personality Questionnaire and four from Cloninger's Temperament and Character Inventory. Broad-sense heritability estimates from best-fitting models were two to three times greater than the narrow-sense heritability estimates for Harm Avoidance, Novelty Seeking, Reward Dependence, Persistence, Extraversion, and Neuroticism. This genetic non-additivity could be due to dominance, additive-by-additive epistasis, or to additive genetic effects combined with higher-order epistasis. Environmental effects unique to twins were detected for both Lie and Psychoticism but accounted for little overall variation. Our results illustrate the increased sensitivity afforded by extending the classical twin design to include siblings, and may provide clues to the evolutionary origins of genetic variation underlying personality.

  11. 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.

  12. 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

    ...HHS gives notice concerning the final effect of the HHS decision to designate a class of employees from the Feed Materials Production Center (FMPC) in Fernald, Ohio, as an addition to the Special Exposure Cohort (SEC) under the Energy Employees Occupational Illness Compensation Program Act of...

  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

    ...HHS gives notice concerning the final effect of the HHS decision to designate a class of employees from the Pantex Plant in Amarillo, Texas, as an addition to the Special Exposure Cohort (SEC) under the Energy Employees Occupational Illness Compensation Program Act of...

  14. 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

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE TREASURY Office of Foreign Assets Control Additional Designation of Person Whose Property and Interests in... piracy and armed robbery at sea off the coast of Somalia. Section 1 of the Order blocks, with...

  15. 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

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE TREASURY Office of Foreign Assets Control Additional Designation of Person Whose Property and Interests in... piracy and armed robbery at sea off the coast of Somalia. Section 1 of the Order blocks, with...

  16. 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

    ... decision to designate a class of employees from the St. Louis Airport Storage Site in St. Louis, Missouri, as an addition to the Special Exposure Cohort (SEC) under the Energy Employees Occupational Illness... Department of Energy, its predecessor agencies, and its contractors and subcontractors who worked in any...

  17. 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...

  18. 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

    ... Analysis and Support, NIOSH, 4676 Columbia Parkway, MS C-46, Cincinnati, OH 45226, Telephone 877-222-7570... 42 U.S.C. 7384q(b), the Secretary of HHS designated the following class of employees as an addition... effective on September 22, 2012, as provided for under 42 U.S.C. 7384l(14)(C). Hence, beginning on...

  19. 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

    ... concerning the final effect of the decision to designate a class of employees at the Lawrence Berkeley National Laboratory in Berkeley, California, as an addition to the Special Exposure Cohort (SEC) under the..., and their contractors and subcontractors who worked at the Lawrence Berkeley National Laboratory...

  20. 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 ...

  1. 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...

  2. 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

    ... notice concerning the final effect of the HHS decision to designate a class of employees from Oak Ridge National Laboratory (X-10), in Oak Ridge, Tennessee, as an addition to the Special Exposure Cohort (SEC..., and their contractors and subcontractors who worked in any area at the Oak Ridge National...

  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

    ... notice concerning the final effect of the HHS decision to designate a class of employees at the Oak Ridge 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,...

  4. 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...

  5. 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.

  6. On variant strategies to solve the magnitude least squares optimization problem in parallel transmission pulse design and under strict SAR and power constraints.

    PubMed

    Hoyos-Idrobo, A; Weiss, P; Massire, A; Amadon, A; Boulant, N

    2014-03-01

    Parallel transmission is a very promising candidate technology to mitigate the inevitable radio-frequency (RF) field inhomogeneity in magnetic resonance imaging at ultra-high field. For the first few years, pulse design utilizing this technique was expressed as a least squares problem with crude power regularizations aimed at controlling the specific absorption rate (SAR), hence the patient safety. This approach being suboptimal for many applications sensitive mostly to the magnitude of the spin excitation, and not its phase, the magnitude least squares (MLS) problem then was first formulated in 2007. Despite its importance and the availability of other powerful numerical optimization methods, the MLS problem yet has been faced almost exclusively by the pulse designer with the so-called variable exchange method. In this paper, we investigate various two-stage strategies consisting of different initializations and nonlinear programming approaches, and incorporate directly the strict SAR and hardware constraints. Several schemes such as sequential quadratic programming, interior point methods, semidefinite programming and magnitude squared least squares relaxations are studied both in the small and large tip angle regimes with RF and static field maps obtained in vivo on a human brain at 7T. Convergence and robustness of the different approaches are analyzed, and recommendations to tackle this specific problem are finally given. Small tip angle and inversion pulses are returned in a few seconds and in under a minute respectively while respecting the constraints, allowing the use of the proposed approach in routine.

  7. Design rules for rational control of polymer glass formation behavior and mechanical properties with small molecular additives

    NASA Astrophysics Data System (ADS)

    Mangalara, Jayachandra Hari; Simmons, David

    Small molecule additives have long been employed to tune polymers' glass formation, mechanical and transport properties. For example, plasticizers are commonly employed to suppress polymer Tg and soften the glassy state, while antiplasticizers, which stiffen the glassy state of a polymer while suppressing its Tg, are employed to enhance protein and tissue preservation in sugar glasses. Recent literature indicates that additives can have a wide range of possible effects, but all of these have not been clearly understood and well appreciated. Here we employ molecular dynamics simulations to establish design rules for the selection of small molecule additives with size, molecular stiffness, and interaction energy chosen to achieve targeted effects on polymer properties. We furthermore find that a given additive's effect on a polymer's Tg can be predicted from its Debye-Waller factor via a function previously found to describe nanoconfinement effects on the glass transition. These results emphasize the potential for a new generation of targeted molecular additives to contribute to more targeted rational design of polymers. We acknowledge the Keck Foundation and the Ohio Supercomputing Center for financial and computational support of this effort, respectively.

  8. 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

    ...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 Brookhaven National Laboratory in Upton, New York, 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.......

  9. 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

    ...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 Metals 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, 2009, as provided for under 42 U.S.C.......

  10. 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......

  11. 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 Piqua Organic Moderated Reactor site in Piqua, Ohio, 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.......

  12. 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…

  13. Magneto-rheological fluids redispersibility - a factorial design study of phosphate shell on carbonyl iron powder with dispersing additives

    NASA Astrophysics Data System (ADS)

    Bombard, Antonio J. F.; Antunes, Laís S.; Balestrassi, Pedro P.; Paiva, Anderson P.

    2009-02-01

    We showed, in a previous paper, that Magneto-Rheological Fluids (MRFs) have different rheology when prepared with Carbonyl Iron Powders (CIP) phosphate (coated or uncoated). This was especially so when done without a magnetic field. This paper employs factorial design to examine the redispersibility and rheology of some MRF formulations; we use the same CIPs but with different dispersing additives. The factors are: CIP A (uncoated) or B (phosphate shell); additives with carboxylic acid or primary amine as the polar group; and n-octyl (C8H17) or n-dodecyl (C12H25) as the alkyl hydrocarbon chain (R-). CIP B was much more redispersible than CIP A, especially with amine additives; typical work values were > 5mJ @ 20 mm depth. In terms of viscosity, CIP A generated lower values, at shear rates above 100 s-1. It also realized higher yield stress values (Ho = 300 kA/m) than CIP B (50% and beyond).

  14. 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.

  15. 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...

  16. 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.

  17. 13-Helix folding of a β/γ-peptide manifold designed from a "minimal-constraint" blueprint.

    PubMed

    Grison, Claire M; Robin, Sylvie; Aitken, David J

    2016-06-14

    A bottom-up design rationale was adopted to devise β/γ-peptide foldamer manifolds which would adopt preferred 13-helix conformations, relying on minimal steric imposition brought by the constituent amino acid residues. In this way, a well-defined 13-helix conformer was revealed for short oligomers of trans-2-aminocyclobutanecarboxylic acid and γ(4)-amino acids in alternation, which gave good topological superposition upon an α-helix motif.

  18. Comparative Electromagnetic and Quasi-Static Simulations of a Shortpulse Propagation along Microstrip Meander Delay Lines with Design Constraints

    NASA Astrophysics Data System (ADS)

    Orlov, Pavel; Gazizov, Talgat; Zabolotsky, Aleksander

    2016-09-01

    A numerical analysis of microstrip meander delay lines is considered. Results of quasi-static and electromagnetic simulations are given. It is shown that when increasing a number of turns and proportionally reducing their length, distortions of a pulse signal in the line are reduced. At the same time, despite structure's electrical width increase, the agreement between the results of quasi-static and electromagnetic analyses is improved. Thus, it is demonstrated that when designing the microstrip meander delay lines with minimal distortions, the quasi-static analysis is relevant.

  19. 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

  20. The environmental constraint needs for design improvements to the Saligny I/LLW-repository near Cernavoda NPP

    SciTech Connect

    Barariu, Gheorghe

    2007-07-01

    The paper presents the new perspectives on the development of the L/ILW Final Repository Project which will be built near Cernavoda NPP. The Repository is designed to satisfy the main performance objectives in accordance to IAEA recommendation. Starting in October 1996, Romania became a country with an operating nuclear power plant. Reactor 2 reached the criticality on May 6, 2007 and it will be put in commercial operation in September 2007. The Ministry of Economy and Finance has decided to proceed with the commissioning of Units 3 and 4 of Cernavoda NPP till 2014. The Strategy for radioactive waste management was elaborated by National Agency for Radioactive Waste (ANDRAD), the jurisdictional authority for definitive disposal and the coordination of nuclear spent fuel and radioactive waste management (Order 844/2004) with attributions established by Governmental Decision (GO) 31/2006. The Strategy specifies the commissioning of the Saligny L/IL Radwaste Repository near Cernavoda NPP in 2014. When designing the L/IL Radwaste Repository, the following prerequisites have been taken into account: 1) Cernavoda NPP will be equipped with 4 Candu 6 units. 2) National Legislation in radwaste management will be reviewed and/or completed to harmonize with UE standards 3) The selected site is now in process of confirmation after a comprehensive set of interdisciplinary investigations. (author)

  1. A Comparison of Dimensional Accuracy of Addition Silicone of Different Consistencies with Two Different Spacer Designs - In-vitro Study

    PubMed Central

    Eswaran, B; Eswaran, MA; Prabhu, R; Geetha, KR; Krishna, GP; Jagadeshwari

    2014-01-01

    Introduction: Dimensional accuracy of impression materials is crucial for the production of working casts in Fixed Prosthodontics. The accurate replication of tooth preparations and their arch position requires impression materials that exhibit limited distortion. Methods: This study was conducted to comparatively evaluate the dimensional accuracy of additional silicones by comparing two different techniques and spacer designs, by measuring the linear changes in interpreparation distance. The impressions were made from a stainless steel master die simulating a three unit bridge. A total 80 die stone (type IV, Ultrarock) models were obtained from the impressions made using two different parameters. The two different parameters are Multimix and Monophasic technique and different spacer designs. Result: The interpreparation distance of the abutments in the casts was measured using a travelling microscope. Each sample was measured thrice and the mean value was calculated. The results obtained were statistically analysed and the values fall within the clinically acceptable range. Conclusion: The most accurate combination is multimix technique with spacer design which uses less bulk of impression material. PMID:25177635

  2. 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.

  3. 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.

  4. Use of physiological constraints to identify quantitative design principles for gene expression in yeast adaptation to heat shock

    PubMed Central

    Vilaprinyo, Ester; Alves, Rui; Sorribas, Albert

    2006-01-01

    Background Understanding the relationship between gene expression changes, enzyme activity shifts, and the corresponding physiological adaptive response of organisms to environmental cues is crucial in explaining how cells cope with stress. For example, adaptation of yeast to heat shock involves a characteristic profile of changes to the expression levels of genes coding for enzymes of the glycolytic pathway and some of its branches. The experimental determination of changes in gene expression profiles provides a descriptive picture of the adaptive response to stress. However, it does not explain why a particular profile is selected for any given response. Results We used mathematical models and analysis of in silico gene expression profiles (GEPs) to understand how changes in gene expression correlate to an efficient response of yeast cells to heat shock. An exhaustive set of GEPs, matched with the corresponding set of enzyme activities, was simulated and analyzed. The effectiveness of each profile in the response to heat shock was evaluated according to relevant physiological and functional criteria. The small subset of GEPs that lead to effective physiological responses after heat shock was identified as the result of the tuning of several evolutionary criteria. The experimentally observed transcriptional changes in response to heat shock belong to this set and can be explained by quantitative design principles at the physiological level that ultimately constrain changes in gene expression. Conclusion Our theoretical approach suggests a method for understanding the combined effect of changes in the expression of multiple genes on the activity of metabolic pathways, and consequently on the adaptation of cellular metabolism to heat shock. This method identifies quantitative design principles that facilitate understating the response of the cell to stress. PMID:16584550

  5. 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.

  6. 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.

  7. 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.

  8. Toxicological features of maleilated polyflavonoids from Pinus radiata (D. Don.) as potential functional additives for biomaterials design.

    PubMed

    García, Danny E; Medina, Paulina A; Zúñiga, Valentina I

    2017-03-14

    Polyflavonoids from Pinus radiata (D. Don.) are an abundant natural oligomers highly desirable as renewable chemicals. However, structural modification of polyflavonoids is a viable strategy in order to use such polyphenols as macrobuilding-blocks for biomaterial design. Polyflavonoids were esterified with three five-member cyclic anhydrides (maleic, itaconic, and citraconic) at 20 °C during 24 h in order to diversify physicochemical-, and biological-properties for agricultural, and food-packaging applications. In addition, the influence of the chemical modification, as well as the chemical structure of the grafting on toxicological features was evaluated. Structural features of derivatives were analyzed by spectroscopy (FT-IR and (1)H-NMR), and the degree of substitution was calculated. Toxicological profile was assessed by using three target species in a wide range of concentration (0.01-100 mgL(-)(1)). Effect of polyflavonoids on the growth rate (Selenastrum capricornutum), mortality (Daphnia magna), and germination and radicle length (Lactuca sativa) was determined. Chemical modification affects the toxicological profile on the derivatives in a high extent. Results described remarkable differences in function of the target specie. The bioassays indicate differences of the polyflavonoids toxicological profile associated to the chemical structure of the grafting. Results allowed conclude that polyflavonoids from pine bark show slight toxic properties.

  9. Resolving manipulator redundancy under inequality constraints

    SciTech Connect

    Cheng, F.T.; Chen, T.H.; Sun, Y.Y. . Dept. of Electrical Engineering)

    1994-02-01

    Due to hardware limitations, physical constraints such as joint rate bounds, joint angle limits, and joint torque constraints always exist. In this paper, these constraints are considered into the general formulation of the redundant inverse kinematic problem. To take these physical constraints into account, the computationally efficient Compact Quadratic Programming (QP) method is formed to resolve the constrained kinematic redundancy problem. In addition, the Compact-Inverse QP method is also formulated to remedy the unescapable singularity problem with inequality constraints. Two examples are given to demonstrate the generality and superiority of these two methods: to eliminate the drift phenomenon caused by self motion and to remedy saturation-type nonlinearity problem.

  10. [Demographic constraints].

    PubMed

    Cartier, M; Veron, J

    1992-01-01

    This is a comparative analysis of China and India's policies and programs designed to reduce the rate of population growth. The authors note that these two countries also differ with regard to the emphasis given to primary, secondary, or higher education and to levels of female labor force participation. They conclude that over the next 10 years both will face a growing population, an excess of manpower over available jobs, and regional disparities in development that could threaten internal stability.

  11. 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...

  12. An Assessment of Some Design Constraints on Heat Production of a 3D Conceptual EGS Model Using an Open-Source Geothermal Reservoir Simulation Code

    SciTech Connect

    Yidong Xia; Mitch Plummer; Robert Podgorney; Ahmad Ghassemi

    2016-02-01

    Performance of heat production process over a 30-year period is assessed in a conceptual EGS model with a geothermal gradient of 65K per km depth in the reservoir. Water is circulated through a pair of parallel wells connected by a set of single large wing fractures. The results indicate that the desirable output electric power rate and lifespan could be obtained under suitable material properties and system parameters. A sensitivity analysis on some design constraints and operation parameters indicates that 1) the fracture horizontal spacing has profound effect on the long-term performance of heat production, 2) the downward deviation angle for the parallel doublet wells may help overcome the difficulty of vertical drilling to reach a favorable production temperature, and 3) the thermal energy production rate and lifespan has close dependence on water mass flow rate. The results also indicate that the heat production can be improved when the horizontal fracture spacing, well deviation angle, and production flow rate are under reasonable conditions. To conduct the reservoir modeling and simulations, an open-source, finite element based, fully implicit, fully coupled hydrothermal code, namely FALCON, has been developed and used in this work. Compared with most other existing codes that are either closed-source or commercially available in this area, this new open-source code has demonstrated a code development strategy that aims to provide an unparalleled easiness for user-customization and multi-physics coupling. Test results have shown that the FALCON code is able to complete the long-term tests efficiently and accurately, thanks to the state-of-the-art nonlinear and linear solver algorithms implemented in the code.

  13. Dynamic Constraint Satisfaction with Reasonable Global Constraints

    NASA Technical Reports Server (NTRS)

    Frank, Jeremy

    2003-01-01

    Previously studied theoretical frameworks for dynamic constraint satisfaction problems (DCSPs) employ a small set of primitive operators to modify a problem instance. They do not address the desire to model problems using sophisticated global constraints, and do not address efficiency questions related to incremental constraint enforcement. In this paper, we extend a DCSP framework to incorporate global constraints with flexible scope. A simple approach to incremental propagation after scope modification can be inefficient under some circumstances. We characterize the cases when this inefficiency can occur, and discuss two ways to alleviate this problem: adding rejection variables to the scope of flexible constraints, and adding new features to constraints that permit increased control over incremental propagation.

  14. 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...

  15. 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...

  16. 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...

  17. Foundations of support constraint machines.

    PubMed

    Gnecco, Giorgio; Gori, Marco; Melacci, Stefano; Sanguineti, Marcello

    2015-02-01

    The mathematical foundations of a new theory for the design of intelligent agents are presented. The proposed learning paradigm is centered around the concept of constraint, representing the interactions with the environment, and the parsimony principle. The classical regularization framework of kernel machines is naturally extended to the case in which the agents interact with a richer environment, where abstract granules of knowledge, compactly described by different linguistic formalisms, can be translated into the unified notion of constraint for defining the hypothesis set. Constrained variational calculus is exploited to derive general representation theorems that provide a description of the optimal body of the agent (i.e., the functional structure of the optimal solution to the learning problem), which is the basis for devising new learning algorithms. We show that regardless of the kind of constraints, the optimal body of the agent is a support constraint machine (SCM) based on representer theorems that extend classical results for kernel machines and provide new representations. In a sense, the expressiveness of constraints yields a semantic-based regularization theory, which strongly restricts the hypothesis set of classical regularization. Some guidelines to unify continuous and discrete computational mechanisms are given so as to accommodate in the same framework various kinds of stimuli, for example, supervised examples and logic predicates. The proposed view of learning from constraints incorporates classical learning from examples and extends naturally to the case in which the examples are subsets of the input space, which is related to learning propositional logic clauses.

  18. 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

    ... Compensation Analysis and Support, NIOSH, 4676 Columbia Parkway, MS C- ] 46, Cincinnati, OH 45226, Telephone... for under 42 U.S.C. 7384q(b), the Secretary of HHS designated the following class of employees as an... designation became effective on September 22, 2012, as provided for under 42 U.S.C. 7384l(14)(C)....

  19. 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

    ... [Federal Register Volume 75, Number 95 (Tuesday, May 18, 2010)] [Notices] [Page 27784] [FR Doc No: 2010-11881] DEPARTMENT OF HEALTH AND HUMAN SERVICES Final Effect of Designation of a Class of Employees... concerning the final effect of the decision to designate a class of employees from Lawrence...

  20. 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

    ... [Federal Register Volume 75, Number 95 (Tuesday, May 18, 2010)] [Notices] [Page 27785] [FR Doc No: 2010-11878] DEPARTMENT OF HEALTH AND HUMAN SERVICES Final Effect of Designation of a Class of Employees... concerning the final effect of the decision to designate a class of employees from Area IV of the...

  1. 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

    ... [Federal Register Volume 75, Number 95 (Tuesday, May 18, 2010)] [Notices] [Page 27784] [FR Doc No: 2010-11880] DEPARTMENT OF HEALTH AND HUMAN SERVICES Final Effect of Designation of a Class of Employees... concerning the final effect of the decision to designate a class of employees from the Nevada Test Site as...

  2. 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

  3. Constraint-Based Scheduling System

    NASA Technical Reports Server (NTRS)

    Zweben, Monte; Eskey, Megan; Stock, Todd; Taylor, Will; Kanefsky, Bob; Drascher, Ellen; Deale, Michael; Daun, Brian; Davis, Gene

    1995-01-01

    Report describes continuing development of software for constraint-based scheduling system implemented eventually on massively parallel computer. Based on machine learning as means of improving scheduling. Designed to learn when to change search strategy by analyzing search progress and learning general conditions under which resource bottleneck occurs.

  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 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,...

  5. 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

    ... Ames Laboratory at Iowa State University during the period from August 13, 1942 through December 31... decision to designate a class of employees from the Ames Laboratory at Iowa State University, as...

  6. 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

    ... HHS decision to designate a class of employees from the Mound Plant in Miamisburg, Ohio, as an... tritium bioassay sample and worked at the Mound Plant in Miamisburg, Ohio from March 1, 1959 through...

  7. 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

    ... notice concerning the final effect of the HHS decision to designate a class of employees from the Mound... contractors and subcontractors who worked at the Mound Plant in Miamisburg, Ohio, from September 1,...

  8. 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...

  9. 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,...

  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

    ... concerning the final effect of the decision to designate a class of employees from Westinghouse Electric Corp... Atomic Weapons Employer employees who worked at Westinghouse Electric Corp., Bloomfield, New Jersey,...

  11. Recommendations for Additional Design Development of Components for the SpinTek Rotary Microfilter Prior to Radioactive Service

    SciTech Connect

    Herman, D.T.

    2004-02-13

    The SpinTek rotary microfilter is being considered as an alternative to crossflow filtration. Prior testing evaluated the vendor's standard design for a 1-disk and 3-disk design. We noted several areas of improvement during the testing of the two filter systems that can be included in the 25-disk plant size unit.This report outlines several potential enhancements and improvements to the vendor's standard design which would extend the lifetime of the unit and increase the ability to perform maintenance for units deployed in radioactive service. The enhancements proposed in this report can be implemented to the current design with minimal impact to the cost and schedule of the purchase of the standard unit. An example of this is the replacement of the current mechanical seal with a bellows seal. The improvements proposed will require an extensive redesign of components found in the current system such as the filter chamber.

  12. 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.

  13. 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...

  14. 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

    ... Winchester Engineering and Analytical Center Site, in Winchester, Massachusetts, as an addition to the... Analytical Center in Winchester, Massachusetts, from January 1, 1952, through December 31, 1961, for a...

  15. 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...

  16. 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

    ... Savannah River Site in Aiken, South Carolina, as an addition to the Special Exposure Cohort (SEC) under the... contractors and subcontractors who worked at the Savannah River Site from January 1, 1953, through...

  17. 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

    ... Engineer Works in Oak Ridge, Tennessee, as an addition to the Special Exposure Cohort (SEC) under the... Carbon Chemicals Corporation (1947-1949) who were employed at the Clinton Engineer Works in Oak...

  18. Adaptive output feedback control for a class of nonlinear systems with full-state constraints

    NASA Astrophysics Data System (ADS)

    Liu, Yan-Jun; Li, Dong-Juan; Tong, Shaocheng

    2014-02-01

    This paper studies an adaptive output-feedback control for a class of nonlinear single-input and single-output (SISO) systems with the full-state constraints. A state observer is designed to estimate those unmeasured states. At present, all the results in the output-feedback area ignore the effects of the full-state constraints. The presence of these constraints results in a complicated procedure and the major difficulties in the design. The barrier Lyapunov function (BLF) and a novel design procedure are given to overcome these difficulties. The adaptation law and the controllers are obtained based on the backstepping design procedure. In addition, only one adjustable parameter needs to be updated, and thus, the online computation burden is alleviated. The stability of the closed-loop system is proven by using the Lyapunov theorem. A simulation example is given to verify the effectiveness of the approach.

  19. 77 FR 42500 - Designation of a Class of Employees for Addition to the Special Exposure Cohort; Correction

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-19

    ... give notice of a decision to designate a class of employees from the Feed Materials Production Center (FMPC) in Fernald, Ohio, also known as the Fernald Environmental Management Project (FEMP), as an... worked at the Feed Materials Production Center (FMPC) in Fernald, Ohio, from January 1, 1968...

  20. 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

    ..., 2013, as provided for under 42 U.S.C. 7384q(b), the Secretary of HHS designated the following class of..., 2013, as provided for under 42 U.S.C. 7384l(14)(C). Hence, beginning on April 5, 2013, members of this... INFORMATION CONTACT: Stuart L. Hinnefeld, Director, Division of Compensation Analysis and Support, NIOSH,...

  1. 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

    ... provided for under 42 U.S.C. Sec. 7384q(b), the Secretary of HHS designated the following class of..., 2013, as provided for under 42 U.S.C. 7384l(14)(C). Hence, beginning on April 5, 2013, members of this... INFORMATION CONTACT: Stuart L. Hinnefeld, Director, Division of Compensation Analysis and Support, NIOSH,...

  2. 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

    ..., National Institute for Occupational Safety and Health (NIOSH), 4676 Columbia Parkway, MS C-46, Cincinnati... under 42 U.S.C. 7384q(b), the Secretary of HHS designated the following class of employees as an... effective on July 27, 2012, as provided for under 42 U.S.C. 7384l(14)(C). Hence, beginning on July 27,...

  3. 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...

  4. 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

    ... Order Reviews A. Executive Order 12866: Regulatory Planning and Review B. Paperwork Reduction Act C... and is subject to CAA section 107(d)(2)(B), which does not require that the Agency issue a notice of.../attainment,'' while a portion of Pinal County is being designated as ``nonattainment.'' This action...

  5. 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

    ... and Prevention, Department of Health and Human Services (HHS). ACTION: Notice. SUMMARY: HHS gives notice concerning the final effect of the HHS decision to designate a class of employees from the Nuclear... Nuclear Metals, Inc. (or a subsequent owner) in West Concord, Massachusetts, during the period...

  6. 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.

  7. Topology optimization of structures with stress constraints: Aeronautical applications

    NASA Astrophysics Data System (ADS)

    París, J.; Martínez, S.; Navarrina, F.; Colominas, I.; Casteleiro, M.

    2010-06-01

    Topology optimization of structures is nowadays the most active and widely studied branch in structural optimization. This paper develops a minimum weight formulation for the topology optimization of continuum structures. This approach also includes stress constraints and addresses important topics like the efficient treatment of a large number of stress constraints, the approach of discrete solutions by using continuum design variables and the computational cost. The proposed formulation means an alternative to maximum stiffness formulations and offers additional advantages. The minimum weight formulation proposed is based on the minimization of the weight of the structure. In addition, stress constraints are included in order to guarantee the feasibility of the final solution obtained. The objective function proposed has been designed to force the convergence to a discrete solution in the final stages of the optimization process. Thus, near discrete solutions are obtained by using continuum design variables. The robustness and reliability of the proposed formulation are verified by solving application examples related to aeronautical industry.

  8. Analytical curve or standard addition method: how to elect and design--a strategy applied to copper determination in sugarcane spirits using AAS.

    PubMed

    Honorato, Fernanda Araujo; Honorato, Ricardo Saldanha; Pimentel, Maria Fernanda; Araujo, Mario Cesar Ugulino

    2002-11-01

    In most instrumental analysis, the analyte concentration is usually obtained the by Analytical Curve Method (ACM) or Standard Addition Method (SAM). Thus, it is important for the analyst to select the most appropriate method, to seek the best conditions of analysis, and to provide parameters of analytical performance. A strategy to do so is proposed in this paper in conjunction with MATLAB software to implement it. The proposed strategy was applied to copper determination by atomic absorption spectrometry in Brazilian sugarcane spirits termed 'Cachaça' and SAM was chosen as the most appropriate method. To select the best experimental design for SAM, the influence of some factors, such as the number of standard additions and concentration levels, the location of the levels and the average concentration of the standard additions were demonstrated. The design with six standard additions, four concentration levels located near the inferior and superior levels and the average concentration of the standard additions closer to zero yielded SAM with an adequate compromise between precision, cost and time of analysis. The uniform distribution of concentration levels, usually used in routine analysis, is not a good design regarding precision. On the other hand, it is adequate when the linear range is unknown. Generally, the proposed strategy can be applied to different instrumental techniques and samples, which aim to improve their analytical performance.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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

    2016-06-15

    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.

  14. 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

  15. Measurement of water by oven evaporation using a novel oven design. 2. Water in motor oils and motor oil additives.

    PubMed

    Margolis, Sam A; Vaishnav, Kevin; Sieber, John R

    2004-11-01

    The measurement of water in lubricating oils is important because water accelerates the corrosion of metal parts and bearings in motors. Some of the additives added to lubricating oils to improve their performance react with the Karl Fischer reagent (KFR) causing a positive bias in the water measurement. A new oven evaporation technique for measuring water in oils has been developed that is automated, requires less sample handling, is easily calibrated, and is capable of measuring relatively small mass fractions of water (> or =50 mg/kg sample). A series of motor oils was analyzed with the standard KFR, a reagent that detects interfering substances that reduce iodine, and the aldehyde-ketone reagent that does not detect substances that react with methanol and form water. The oil samples were heated to 107 degrees C and then reheated to 160 degrees C. At both temperatures, material was measured by both KFRs, but only zinc dithiophosphate released sulfur compounds that would react with the reagent that detects interfering substances. Mass fractions of between 20 and 70% of the volatile material released at either temperature were measured with the standard KFR but not with the aldehyde-ketone reagent. These results demonstrate that there are a number of sources of positive bias in the measurement of water in motor oils and that the standard KFR cannot be used to measure water in motor oils and motor oil additives. These results also indicate that some of the material reacts with methanol to form water. Finally, these results suggest that some of the material that is volatile at 160 degrees C and not at 107 degrees C may be water that is physically occluded or may be substances that react with diethyleneglycol monomethylether to produce water.

  16. 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.

  17. 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.

  18. Design and analysis of a piezoelectric material based touch screen with additional pressure and its acceleration measurement functions

    NASA Astrophysics Data System (ADS)

    Chu, Xiang-Cheng; Liu, Jia-Yi; Gao, Ren-Long; Chang, Jie; Li, Long-Tu

    2013-12-01

    Touch screens are becoming more and more prevalent in everyday environments due to their convenience and humanized operation. In this paper, a piezoelectric material based touch screen is developed and investigated. Piezoelectric ceramics arrayed under the touch panel at the edges or corners are used as tactile sensors to measure the touch positioning point similarly to conventional touch screens. However, additional touch pressure and its acceleration performance can also be obtained to obtain a higher-level human-machine interface. The piezoelectric ceramics can also be added to a traditional touch screen structure, or they can be used independently to construct a novel touch screen with a high light transmittance approach to a transparent glass. The piezoelectric ceramics were processed from PZT piezoelectric ceramic powder into a round or rectangular shape. According to the varied touch position and physical press strength of a finger, or even a gloved hand or fingernail, the piezoelectric tactile sensors will have different output voltage responses. By calculating the ratio of different piezoelectric tactile sensors’ responses and summing up all piezoelectric tactile sensors’ output voltages, the touch point position, touch pressure and touch force acceleration can be detected. A prototype of such a touch screen is manufactured and its position accuracy, touch pressure and response speed are measured in detail. The experimental results show that the prototype has many advantages such as high light transmittance, low energy cost and high durability.

  19. 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.

  20. Functional constraints on phenomenological coefficients

    NASA Astrophysics Data System (ADS)

    Klika, Václav; Pavelka, Michal; Benziger, Jay B.

    2017-02-01

    Thermodynamic fluxes (diffusion fluxes, heat flux, etc.) are often proportional to thermodynamic forces (gradients of chemical potentials, temperature, etc.) via the matrix of phenomenological coefficients. Onsager's relations imply that the matrix is symmetric, which reduces the number of unknown coefficients is reduced. In this article we demonstrate that for a class of nonequilibrium thermodynamic models in addition to Onsager's relations the phenomenological coefficients must share the same functional dependence on the local thermodynamic state variables. Thermodynamic models and experimental data should be validated through consistency with the functional constraint. We present examples of coupled heat and mass transport (thermodiffusion) and coupled charge and mass transport (electro-osmotic drag). Additionally, these newly identified constraints further reduce the number of experiments needed to describe the phenomenological coefficient.

  1. 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.

  2. 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.

  3. 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.

  4. Constraints on the density perturbation spectrum from primordial black holes

    NASA Astrophysics Data System (ADS)

    Green, Anne M.; Liddle, Andrew R.

    1997-11-01

    We reexamine the constraints on the density perturbation spectrum, including its spectral index n, from the production of primordial black holes. The standard cosmology, where the Universe is radiation dominated from the end of inflation up until the recent past, was studied by Carr, Gilbert, and Lidsey; we correct two errors in their derivation and find a significantly stronger constraint than they did: n<~1.25 rather than their 1.5. We then consider an alternative cosmology in which a second period of inflation, known as thermal inflation and designed to solve additional relic overdensity problems, occurs at a lower-energy scale than the main inflationary period. In that case, the constraint weakens to n<~1.3, and thermal inflation also leads to a ``missing mass'' range 1018 g<~M<~1026 g in which primordial black holes cannot form. Finally, we discuss the effect of allowing for the expected non-Gaussianity in the density perturbations predicted by Bullock and Primack, which can weaken the constraints further by up to 0.05.

  5. On Random Betweenness Constraints

    NASA Astrophysics Data System (ADS)

    Goerdt, Andreas

    Ordering constraints are analogous to instances of the satisfiability problem in conjunctive normalform, but instead of a boolean assignment we consider a linear ordering of the variables in question. A clause becomes true given a linear ordering iff the relative ordering of its variables obeys the constraint considered.

  6. 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…

  7. 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…

  8. 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.

  9. A compendium of chameleon constraints

    NASA Astrophysics Data System (ADS)

    Burrage, Clare; Sakstein, Jeremy

    2016-11-01

    The chameleon model is a scalar field theory with a screening mechanism that explains how a cosmologically relevant light scalar can avoid the constraints of intra-solar-system searches for fifth-forces. The chameleon is a popular dark energy candidate and also arises in f(R) theories of gravity. Whilst the chameleon is designed to avoid historical searches for fifth-forces it is not unobservable and much effort has gone into identifying the best observables and experiments to detect it. These results are not always presented for the same models or in the same language, a particular problem when comparing astrophysical and laboratory searches making it difficult to understand what regions of parameter space remain. Here we present combined constraints on the chameleon model from astrophysical and laboratory searches for the first time and identify the remaining windows of parameter space. We discuss the implications for cosmological chameleon searches and future small-scale probes.

  10. 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.

  11. 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

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Food additives

    MedlinePlus

    ... or natural. Natural food additives include: Herbs or spices to add flavor to foods Vinegar for pickling ... Certain colors improve the appearance of foods. Many spices, as well as natural and man-made flavors, ...

  18. 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.

  19. 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.

  20. NMR Constraints Analyser: a web-server for the graphical analysis of NMR experimental constraints

    PubMed Central

    Heller, Davide Martin; Giorgetti, Alejandro

    2010-01-01

    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 PMID:20513646

  1. 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.

  2. Improvements in post-OPC data constraints for enhanced process corrections

    NASA Astrophysics Data System (ADS)

    Burns, Ryan L.; Cui, Yuping; Zhao, Zengqin; Stobert, Ian; LaCour, Pat; Yehia, Ayman; Madkour, Kareem; Gheith, Mohamed; Seoud, Ahmed

    2006-03-01

    Current state-of-the-art OPC (optical proximity correction) for 2-dimensional features consists of optimized fragmentation followed by site simulation and subsequent iterations to adjust fragment locations and minimize edge placement error (EPE). Internal and external constraints have historically been available in production quality code to limit the movement of certain fragments, and this provides additional control for OPC. Values for these constraints are left to engineering judgment, and can be based on lithography process limitations, mask house process limitations, or mask house inspection limitations. Often times mask house inspection limitations are used to define these constraints. However, these inspection restrictions are generally more complex than the 2 degrees of freedom provided in existing standard OPC software. Ideally, the most accurate and robust OPC software would match the movement constraints to the defect inspection requirements, as this prevents over-constraining the OPC solution. This work demonstrates significantly improved 2-D OPC correction results based on matching movement constraints to inspection limitations. Improvements are demonstrated on a created array of 2D designs as well as critical level chip designs used in 45nm technology. Enhancements to OPC efficacy are proven for several types of features. Improvements in overall EPE (edge placement error) are demonstrated for several different types of structures, including mushroom type landing pads, iso crosses, and H-bar structures. Reductions in corner rounding are evident for several 2-dimensional structures, and are shown with dense print image simulations. Dense arrays (SRAM) processed with the new constraints receive better overall corrections and convergence. Furthermore, OPC and ORC (optical rules checking) simulations on full chip test sites with the advanced constraints have resulted in tighter EPE distributions, and overall improved printing to target.

  3. Constraints on relaxion windows

    NASA Astrophysics Data System (ADS)

    Choi, Kiwoon; Im, Sang Hui

    2016-12-01

    We examine the low energy phenomenology of the relaxion solution to the weak scale hierarchy problem. Assuming that the Hubble friction is responsible for a dissipation of the relaxion energy, we identify the cosmological relaxion window which corresponds to the parameter region compatible with a given value of the acceptable number of inflationary e-foldings. We then discuss a variety of observational constraints on the relaxion window, including those from astrophysical and cosmological considerations. We find that majority of the parameter space with a relaxion mass m ϕ ≳ 100 eV or a relaxion decay constant f ≲107GeV is excluded by existing constraints. There is an interesting parameter region with m ϕ ˜ 0 .2 - 10 GeV and f ˜ few - 200 TeV, which is allowed by existing constraints, but can be probed soon by future beam dump experiments such as the SHiP experiment, or by improved EDM experiments.

  4. Critical examination of isolation system design paradigms for a coupled powertrain and frame: Partial torque roll axis decoupling methods given practical constraints

    NASA Astrophysics Data System (ADS)

    Liette, Jared; Dreyer, Jason T.; Singh, Rajendra

    2014-12-01

    The torque roll axis motion decoupling concept is analytically and computationally studied in a realistic coupled powertrain and frame system using discrete, proportionally damped linear models. Recently, Hu and Singh (2012 [1]) (Journal of Sound and Vibration 331 (2012) 1498-1518) proposed new paradigms to fully decouple such a system. However, critical examination shows that the derivation does not always lead to a physically realizable system, as each powertrain mount is not referenced to a single location. This deficiency is overcome by deriving mount compatibility conditions to ensure realistic mount positions which are incorporated into proposed decoupling conditions. It is mathematically shown that full decoupling is not possible for a practical system, and therefore partial decoupling paradigms are pursued. Powertrain mount design using only the decoupled powertrain achieves better decoupling than minimizing conditions for the coupled system using a total least squares method. Further decoupling is obtained through frame isolation design using a decoupled frame model such that the torque roll mode is dominant over the frequency range considered. Other methods for limiting frame coupling are also briefly discussed.

  5. 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.

  6. Regularized Mathematical Programs with Stochastic Equilibrium Constraints: Estimating Structural Demand Models

    DTIC Science & Technology

    2013-07-23

    equilibrium constraints involving only single-valued Lipschitz continuous functions. In addition, sampling has the further effect of replacing the...constraints, based on regularization, that replaces them by equilibrium constraints involving only single-valued Lipschitz continuous functions. In addition...only single-valued Lipschitz continuous functions. In addition, sampling has the further effect of replacing the ‘simplified’ equilibrium constraints by

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. Learning and Applying Contextual Constraints in Sentence Comprehension

    DTIC Science & Technology

    1988-06-08

    learns to perform these tasks through practice on Processing example sentence/event pairs. The learning procedure allows the model’to take a long...and to anticipate additional constituents. The network learns to perform these tasks through practice on processing example sentence/event pairs. The...constraints. Together, the constraints lead to a coherent interpretation of the sentence (MacWhinney, 1987). These constraints are not typically all

  12. Constraints on scattering amplitudes in multistate Landau-Zener theory

    NASA Astrophysics Data System (ADS)

    Sinitsyn, Nikolai A.; Lin, Jeffmin; Chernyak, Vladimir Y.

    2017-01-01

    We derive a set of constraints, which we will call hierarchy constraints, on scattering amplitudes of an arbitrary multistate Landau-Zener model (MLZM). The presence of additional symmetries can transform such constraints into nontrivial relations between elements of the transition probability matrix. This observation can be used to derive complete solutions of some MLZMs or, for models that cannot be solved completely, to reduce the number of independent elements of the transition probability matrix.

  13. Constraints on scattering amplitudes in multistate Landau-Zener theory

    DOE PAGES

    Sinitsyn, Nikolai A.; Lin, Jeffmin; Chernyak, Vladimir Y.

    2017-01-30

    Here, we derive a set of constraints, which we will call hierarchy constraints, on scattering amplitudes of an arbitrary multistate Landau-Zener model (MLZM). The presence of additional symmetries can transform such constraints into nontrivial relations between elements of the transition probability matrix. This observation can be used to derive complete solutions of some MLZMs or, for models that cannot be solved completely, to reduce the number of independent elements of the transition probability matrix.

  14. Precision constraints on extra fermion generations.

    PubMed

    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.

  15. Community-Based Health Education Programs Designed to Improve Clinical Measures Are Unlikely to Reduce Short-Term Costs or Utilization Without Additional Features Targeting These Outcomes.

    PubMed

    Burton, Joe; Eggleston, Barry; Brenner, Jeffrey; Truchil, Aaron; Zulkiewicz, Brittany A; Lewis, Megan A

    2016-06-07

    Stakeholders often expect programs for persons with chronic conditions to "bend the cost curve." This study assessed whether a diabetes self-management education (DSME) program offered as part of a multicomponent initiative could affect emergency department (ED) visits, hospital stays, and the associated costs for an underserved population in addition to the clinical indicators that DSME programs attempt to improve. The program was implemented in Camden, New Jersey, by the Camden Coalition of Healthcare Providers to address disparities in diabetes care. Data used are from medical records and from patient-level information about hospital services from Camden's hospitals. Using multivariate regression models to control for individual characteristics, changes in utilization over time and changes relative to 2 comparison groups were assessed. No reductions in ED visits, inpatient stays, or costs for participants were found over time or relative to the comparison groups. High utilization rates and costs for diabetes are associated with longer term disease progression and its sequelae; thus, DSME or peer support may not affect these in the near term. Some clinical indicators improved among participants, and these might lead to fewer costly adverse health events in the future. DSME deployed at the community level, without explicit segmentation and targeting of high health care utilizers or without components designed to affect costs and utilization, should not be expected to reduce short-term medical needs for participating individuals or care-seeking behaviors such that utilization is reduced. Stakeholders must include financial outcomes in a program's design if those outcomes are to improve. (Population Health Management 20XX;XX:XXX-XXX).

  16. A constraint algorithm for singular Lagrangians subjected to nonholonomic constraints

    SciTech Connect

    de Leon, M.; de Diego, D.M.

    1997-06-01

    We construct a constraint algorithm for singular Lagrangian systems subjected to nonholonomic constraints which generalizes that of Dirac for constrained Hamiltonian systems. {copyright} {ital 1997 American Institute of Physics.}

  17. 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,…

  18. Hierarchical constraint processes for shape analysis.

    PubMed

    Davis, L S; Henderson, T C

    1981-03-01

    A major application of syntactic pattern recognition is the analysis of two-dimensional shape. This paper describes a new syntactic shape analysis technique which combines the constraint propagation techniques which have been so successful in computer vision with the syntactic representation techniques which have been successfully applied to a wide variety of shape analysis problems. Shapes are modeled by stratified shape grammars. These grammars are designed so that local constraints can be compiled from the grammar describing the appearance of pieces of shape at various levels of description. Applications to the analysis of airplane shapes are presented.

  19. 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

    Ito, Yoritsugu; Kohno, Yuki; Nakamura, Nobuhumi; Ohno, Hiroyuki

    2013-09-05

    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.

  20. 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.

  1. Evaluation of the methylene blue addition in binary polymeric systems composed by poloxamer 407 and Carbopol 934P using quality by design: rheological, textural, and mucoadhesive analysis.

    PubMed

    Junqueira, Mariana Volpato; Borghi-Pangoni, Fernanda Belincanta; Ferreira, Sabrina Barbosa de Souza; Bruschi, Marcos Luciano

    2016-12-01

    This study describes the investigation about the physicochemical behavior of methylene blue (Mb) addition to systems containing poloxamer 407 (Polox), Carbopol 934P (Carb), intended to be locally used by photodynamic therapy. A factorial design 2(3) (plus center point) was used to analyze the rheological, mucoadhesive and textural properties of the preparations. Systems containing the lower concentrations of Polox (15 and 17.5%, w/w) exhibited pseudoplastic flow and low degrees of rheopexy. On the other hand, at higher Polox concentration (20%, w/w) the systems display plastic flow and thixotropy. Carb and Mb exhibited a negative influence for the consistency and flow behavior index, due to the interaction between them. For most of the formulations, the increase of Polox and Mb content significantly increased storage modulus, loss modulus and dynamic viscosity. The systems display a sol-gel transition temperature, existing as a liquid at room temperature and gel at 29-37 °C. Increasing the temperature and the polymer concentration, the compressional properties of systems significantly increased. The mucoadhesion was noted to all formulations, except to systems composed by 15% (w/w) of Polox. The analyses enabled to understand and predict the performance of formulations and the polymer-Mb interactions, tailoring to the suit systems (Polox/Carb/Mb): 17.5/0.50/0.20 and 20/0.15/0.25.

  2. (non) Emergent Constraints

    NASA Astrophysics Data System (ADS)

    Jackson, C. S.; Hattab, M. W.; Huerta, G.

    2014-12-01

    Emergent constraints are observable quantities that provide some physical basis for testing or predicting how a climate model will respond to greenhouse gas forcing. Very few such constraints have been identified for the multi-model CMIP archive. Here we explore the question of whether constraints that apply to a single model, a perturbed parameter ensemble (PPE) of the Community Atmosphere Model (CAM3.1), can be applied to predicting the climate sensitivities of models within the CMIP archive. In particular we construct our predictive patterns from multivariate EOFs of the CAM3.1 ensemble control climate. Multiple regressive statistical models were created that do an excellent job of predicting CAM3.1 sensitivity to greenhouse gas forcing. However, these same patterns fail spectacularly to predict sensitivities of models within the CMIP archive. We attribute this failure to several factors. First, and perhaps the most important, is that the structures affecting climate sensitivity in CAM3.1 have a unique signature in the space of our multivariate EOF patterns that are unlike any other climate model. That is to say, we should not expect CAM3.1 to represent the way another models within CMIP archive respond to greenhouse gas forcing. The second, perhaps related, reason is that the CAM3.1 PPE does a poor job of spanning the range of climates and responses found within the CMIP archive. We shall discuss the implications of these results for the prospect of finding emergent constraints within the CMIP archive. We will also discuss what this may mean for establishing uncertainties in climate projections.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Design of the SHAPE-2 study: the effect of physical activity, in addition to weight loss, on biomarkers of postmenopausal breast cancer risk

    PubMed Central

    2013-01-01

    Background Physical inactivity and overweight are two known risk factors for postmenopausal breast cancer. Former exercise intervention studies showed that physical activity influences sex hormone levels, known to be related to postmenopausal breast cancer, mainly when concordant loss of body weight was achieved. The question remains whether there is an additional beneficial effect of physical activity when weight loss is reached. The aim of this study is to investigate the effect attributable to exercise on postmenopausal breast cancer risk biomarkers, when equivalent weight loss is achieved compared with diet-induced weight loss. Design The SHAPE-2 study is a three-armed, multicentre trial. 243 sedentary, postmenopausal women who are overweight or obese (BMI 25–35 kg/m2) are enrolled. After a 4-6 week run-in period, wherein a baseline diet is prescribed, women are randomly allocated to (1) a diet group, (2) an exercise group or (3) a control group. The aim of both intervention groups is to lose an amount of 5–6 kg body weight in 10–14 weeks. The diet group follows an energy restricted diet and maintains the habitual physical activity level. The exercise group participates in a 16-week endurance and strength training programme of 4 hours per week. Furthermore, they are prescribed a moderate caloric restriction. The control group is asked to maintain body weight and continue the run-in baseline diet. Measurements include blood sampling, questionnaires, anthropometrics (weight, height, waist and hip circumference), maximal cycle exercise test (VO2peak), DEXA-scan (body composition) and abdominal MRI (subcutaneous and visceral fat). Primary outcomes are serum levels of oestradiol, oestrone, testosterone and sex hormone binding globulin (SHBG). Discussion This study will give insight in the potential attributable effect of physical activity on breast cancer risk biomarkers and whether this effect is mediated by changes in body composition, in postmenopausal

  10. 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.

  11. 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

  12. The Design of Shape from Motion Constraints

    DTIC Science & Technology

    1993-09-01

    HIV, kolifi I u~li ci e’. lie Ii uu’i . lilwul lleeli. iii-’ plI leI - il..iiiililI ic (.1-. 1/.eiuie (lie opi l le L!.iillf andiI’ a lIt- -1uLll lIii...all (class I ) so I hial oiil\\- lit’ tlt’sjrt’I p~at Ii Imsse IrI1oul11gl I It’I ft’et’d’er. 5. Remove other paths: If th l mnt’lailliug pathls...or. /niI all jug) ImIl lie! I lie 1hi1lt rlilill ed pat h. ) ’I’lis (tleftl~Sto at (lass 3~ fee( lei . (g~(~)lIIwtIX l’mi ’Fiii lli 1.2. (ii) Redirect

  13. Helicopter vibration reduction using structural optimization with aeroelastic/multidisciplinary constraints - A survey

    NASA Technical Reports Server (NTRS)

    Friedmann, Peretz P.

    1991-01-01

    This paper presents a survey of the state-of-the-art in the field of structural optimization when applied to vibration reduction of helicopters in forward flight with aeroelastic and multidisciplinary constraints. It emphasizes the application of the modern approach where the optimization is formulated as a mathematical programming problem, the objective function consists of the vibration levels at the hub, and behavior constraints are imposed on the blade frequencies and aeroelastic stability margins, as well as on a number of additional ingredients that can have a significant effect on the overall performance and flight mechanics of the helicopter. It is shown that the integrated multidisciplinary optimization of rotorcraft offers the potential for substantial improvements, which can be achieved by careful preliminary design and analysis without requiring additional hardware such as rotor vibration absorbers of isolation systems.

  14. 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.

  15. 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.

  16. Patterns of thermal constraint on ectotherm activity.

    PubMed

    Gunderson, Alex R; Leal, Manuel

    2015-05-01

    Thermal activity constraints play a major role in many aspects of ectotherm ecology, including vulnerability to climate change. Therefore, there is strong interest in developing general models of the temperature dependence of activity. Several models have been put forth (explicitly or implicitly) to describe such constraints; nonetheless, tests of the predictive abilities of these models are lacking. In addition, most models consider activity as a threshold trait instead of considering continuous changes in the vigor of activity among individuals. Using field data for a tropical lizard (Anolis cristatellus) and simulations parameterized by our observations, we determine how well various threshold and continuous-activity models match observed activity patterns. No models accurately predicted activity under all of the thermal conditions that we considered. In addition, simulations showed that the performance of threshold models decreased as temperatures increased, which is a troubling finding given the threat of global climate change. We also find that activity rates are more sensitive to temperature than are the physiological traits often used as a proxy for fitness. We present a model of thermal constraint on activity that integrates aspects of both the threshold model and the continuous-activity model, the general features of which are supported by activity data from other species. Overall, our results demonstrate that greater attention should be given to fine-scale patterns of thermal constraint on activity.

  17. Polylactides in additive biomanufacturing.

    PubMed

    Poh, Patrina S P; Chhaya, Mohit P; Wunner, Felix M; De-Juan-Pardo, Elena M; Schilling, Arndt F; Schantz, Jan-Thorsten; van Griensven, Martijn; Hutmacher, Dietmar W

    2016-12-15

    New advanced manufacturing technologies under the alias of additive biomanufacturing allow the design and fabrication of a range of products from pre-operative models, cutting guides and medical devices to scaffolds. The process of printing in 3 dimensions of cells, extracellular matrix (ECM) and biomaterials (bioinks, powders, etc.) to generate in vitro and/or in vivo tissue analogue structures has been termed bioprinting. To further advance in additive biomanufacturing, there are many aspects that we can learn from the wider additive manufacturing (AM) industry, which have progressed tremendously since its introduction into the manufacturing sector. First, this review gives an overview of additive manufacturing and both industry and academia efforts in addressing specific challenges in the AM technologies to drive toward AM-enabled industrial revolution. After which, considerations of poly(lactides) as a biomaterial in additive biomanufacturing are discussed. Challenges in wider additive biomanufacturing field are discussed in terms of (a) biomaterials; (b) computer-aided design, engineering and manufacturing; (c) AM and additive biomanufacturing printers hardware; and (d) system integration. Finally, the outlook for additive biomanufacturing was discussed.

  18. Kinetics and Thermodynamics of Reversible Thiol Additions to Mono- and Diactivated Michael Acceptors: Implications for the Design of Drugs That Bind Covalently to Cysteines.

    PubMed

    Krenske, Elizabeth H; Petter, Russell C; Houk, K N

    2016-12-02

    Additions of cysteine thiols to Michael acceptors underpin the mechanism of action of several covalent drugs (e.g., afatinib, osimertinib, ibrutinib, neratinib, and CC-292). Reversible Michael acceptors have been reported in which an additional electron-withdrawing group was added at the α-carbon of a Michael acceptor. We have performed density functional theory calculations to determine why thiol additions to these Michael acceptors are reversible. The α-EWG group stabilizes the anionic transition state and intermediate of the Michael addition, but less intuitively, it destabilizes the neutral adduct. This makes the reverse reaction (elimination) both faster and more thermodynamically favorable. For thiol addition to be reversible, the Michael acceptor must also contain a suitable substituent on the β-carbon, such as an aryl or branched alkyl group. Computations explain how these structural elements contribute to reversibility and the ability to tune the binding affinities and the residence times of covalent inhibitors.

  19. 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.

  20. 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…

  1. Impact of longitudinal flying qualities upon the design of a transport with active controls

    NASA Technical Reports Server (NTRS)

    Sliwa, S. M.

    1980-01-01

    Direct constrained parameter optimization was used to optimally size a medium range transport for minimum direct operating cost. Several stability and control constraints were varied to study the sensitivity of the configuration to specifying the unaugmented flying qualities of transports designed with relaxed static stability. Additionally, a number of handling quality related design constants were studied with respect to their impact to the design.

  2. 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…

  3. Neural constraints on learning.

    PubMed

    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

    2014-08-28

    Learning, whether motor, sensory or cognitive, requires networks of neurons to generate new activity patterns. As some behaviours are easier to learn than others, we asked if some neural activity patterns are easier to generate than others. Here we investigate whether an existing network constrains the patterns that a subset of its neurons is capable of exhibiting, and if so, what principles define this constraint. We employed a closed-loop intracortical brain-computer interface learning paradigm in which Rhesus macaques (Macaca mulatta) controlled a computer cursor by modulating neural activity patterns in the primary motor cortex. Using the brain-computer interface 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. The activity of a neural population can be represented in a high-dimensional space (termed the neural space), wherein each dimension corresponds to the activity of one neuron. These characteristic activity patterns comprise a low-dimensional subspace (termed the intrinsic manifold) within the neural space. The intrinsic manifold presumably reflects constraints imposed by the underlying neural circuitry. Here we show that the animals could readily learn to proficiently control the cursor using neural activity patterns that were within the intrinsic manifold. However, animals were less able to learn to proficiently control the cursor using activity patterns that were outside of the intrinsic manifold. These results suggest that the existing structure of a network can shape learning. On a timescale of hours, it seems 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

  4. Generating Natural Language Under Pragmatic Constraints.

    DTIC Science & Technology

    1987-03-01

    THIS PAGIE (When Dae deureel Due to the flexibility of language , speakers can communicate far more than Just the literal content of tile words they use...flexibility of language , speakers can communicate far more than just the literal content of the words they use; the additional information usually serves...each of three domains, various paragraphs that differ in slant, content , and style. Generating Natural Language Under Pragmatic Constraints A

  5. 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.

  6. 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.

  7. Approximation of Engine Casing Temperature Constraints for Casing Mounted Electronics

    NASA Technical Reports Server (NTRS)

    Kratz, Jonathan; Culley, Dennis; Chapman, Jeffryes

    2016-01-01

    The performance of propulsion engine systems is sensitive to weight and volume considerations. This can severely constrain the configuration and complexity of the control system hardware. Distributed Engine Control technology is a response to these concerns by providing more flexibility in designing the control system, and by extension, more functionality leading to higher performing engine systems. Consequently, there can be a weight benefit to mounting modular electronic hardware on the engine core casing in a high temperature environment. This paper attempts to quantify the in-flight temperature constraints for engine casing mounted electronics. In addition, an attempt is made at studying heat soak back effects. The Commercial Modular Aero Propulsion System Simulation 40k (C-MAPSS40k) software is leveraged with real flight data as the inputs to the simulation. A two-dimensional (2-D) heat transfer model is integrated with the engine simulation to approximate the temperature along the length of the engine casing. This modification to the existing C-MAPSS40k software will provide tools and methodologies to develop a better understanding of the requirements for the embedded electronics hardware in future engine systems. Results of the simulations are presented and their implications on temperature constraints for engine casing mounted electronics is discussed.

  8. 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…

  9. 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…

  10. 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.

  11. 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…

  12. 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)

  13. 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.

  14. 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…

  15. 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.

  16. Improving SALT productivity by using the theory of constraints

    NASA Astrophysics Data System (ADS)

    Coetzee, Johannes C.; Väisänen, Petri; O'Donoghue, Darragh E.; Kotze, Paul; Romero Colmenero, Encarni; Miszalski, Brent; Crawford, Steven M.; Kniazev, Alexei; Depagne, Éric; Rabe, Paul; Hettlage, Christian

    2016-07-01

    SALT, the Southern African Large Telescope, is a very cost effective 10 m class telescope. The operations cost per refereed science paper is currently approximately $70,000. To achieve this competitive advantage, specific design tradeoffs had to be made leading to technical constraints. On the other hand, the telescope has many advantages, such as being able to rapidly switch between different instruments and observing modes during the night. We provide details of the technical and operational constraints and how they were dealt with, by applying the theory of constraints, to substantially improve the observation throughput during the last semester.

  17. Improving planning, design, reporting and scientific quality of animal experiments by using the Gold Standard Publication Checklist, in addition to the ARRIVE guidelines.

    PubMed

    Hooijmans, Carlijn R; de Vries, Rob; Leenaars, Marlies; Curfs, Jo; Ritskes-Hoitinga, Merel

    2011-03-01

    Several studies have demonstrated serious omissions in the way research that use animals is reported. In order to improve the quality of reporting of animal experiments, the Animals in research: reporting in vivo experiments (ARRIVE) Guidelines were published in the British Journal of Pharmacology in August 2010. However, not only the quality of reporting of completed animal studies needs to be improved, but also the design and execution of new experiments. With both these goals in mind, we published the Gold Standard Publication Checklist (GSPC) in May 2010, a few months before the ARRIVE guidelines appeared. In this letter, we compare the GSPC checklist with the ARRIVE Guidelines. The GSPC describes certain items in more detail, which makes it both easier to use when designing and conducting an experiment and particularly suitable for making systematic reviews of animal studies more feasible. In order to improve not only the reporting but also the planning, design, execution and thereby, the scientific quality of animal experiments, we strongly recommend to all scientists involved in animal experimentation and to editors of journals publishing animal studies to take a closer look at the contents of both the ARRIVE guidelines and GSPC, and select the set of guidelines which is most appropriate for their particular situation.

  18. Architecture in Mission Integration, Choreographing Constraints

    NASA Technical Reports Server (NTRS)

    Jones, Rod

    2000-01-01

    In any building project the Architect's role and skill is to balance the client's requirements with the available technology, a site and budget. Time, place and resources set the boundaries and constraints of the project. If these boundaries are correctly understood and respected by the Architect they can be choreographed into producing a facility that abides by those constraints and successfully meets the clients needs. The design and assembly of large scale space facilities whether in orbit around or on the surface of a planet require and employs these same skills. In this case the site is the International Space Station (ISS) which operates at a nominal rendezvous altitude of 220 nautical miles. With supplies to support a 7 day mission the Shuttle nominally has a cargo capacity of 35,000 pounds to that altitude. Through the Mission Integration process the Launch Package Management Team choreographs the constraints of ascent performance, hardware design, cargo, rendezvous, mission duration and assembly time in order to meet the mission objective.

  19. Design, Synthesis, and Characterization of α-Ketoheterocycles That Additionally Target the Cytosolic Port Cys269 of Fatty Acid Amide Hydrolase

    PubMed Central

    2015-01-01

    A series of α-ketooxazoles incorporating electrophiles at the C5 position of the pyridyl ring of 2 (OL-135) and related compounds were prepared and examined as inhibitors of fatty acid amide hydrolase (FAAH) that additionally target the cytosolic port Cys269. From this series, a subset of the candidate inhibitors exhibited time-dependent FAAH inhibition and noncompetitive irreversible inactivation of the enzyme, consistent with the targeted Cys269 covalent alkylation or addition, and maintained or enhanced the intrinsic selectivity for FAAH versus other serine hydrolases. A preliminary in vivo assessment demonstrates that these inhibitors raise endogenous brain levels of anandamide and other FAAH substrates upon intraperitoneal (i.p.) administration to mice, with peak levels achieved within 1.5–3 h, and that the elevations of the signaling lipids were maintained >6 h, indicating that the inhibitors effectively reach and remain active in the brain, inhibiting FAAH for a sustained period. PMID:24456116

  20. Output feedback boundary control of an axially moving system with input saturation constraint.

    PubMed

    Zhao, Zhijia; Liu, Yu; Luo, Fei

    2017-02-28

    This paper is concerned with boundary control for an axially moving belt system with high acceleration/deceleration subject to the input saturation constraint. The dynamics of belt system is expressed by a nonhomogeneous hyperbolic partial differential equation coupled with an ordinary differential equation. First, state feedback boundary control is designed for the case that the boundary states of the belt system can be measured. Subsequently, output feedback boundary control is developed when some of the system states can not be accurately obtained. The well-posedness and the uniformly bounded stability of the closed-loop system are achieved through rigorous mathematical analysis. In addition, high-gain observers are utilized to estimate those unmeasurable states, the auxiliary system is introduced to eliminate the constraint effects of the input saturation, and the disturbance observer is adopted to cope with unknown boundary disturbance. Finally, the control performance of the belt system is illustrated by carrying out numerical simulations.

  1. 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.

  2. About some types of constraints in problems of routing

    NASA Astrophysics Data System (ADS)

    Petunin, A. A.; Polishuk, E. G.; Chentsov, A. G.; Chentsov, P. A.; Ukolov, S. S.

    2016-12-01

    Many routing problems arising in different applications can be interpreted as a discrete optimization problem with additional constraints. The latter include generalized travelling salesman problem (GTSP), to which task of tool routing for CNC thermal cutting machines is sometimes reduced. Technological requirements bound to thermal fields distribution during cutting process are of great importance when developing algorithms for this task solution. These requirements give rise to some specific constraints for GTSP. This paper provides a mathematical formulation for the problem of thermal fields calculating during metal sheet thermal cutting. Corresponding algorithm with its programmatic implementation is considered. The mathematical model allowing taking such constraints into account considering other routing problems is discussed either.

  3. A Hybrid Constraint Representation and Reasoning Framework

    NASA Technical Reports Server (NTRS)

    Golden, Keith; Pang, Wan-Lin

    2003-01-01

    This paper introduces JNET, a novel constraint representation and reasoning framework that supports procedural constraints and constraint attachments, providing a flexible way of integrating the constraint reasoner with a run- time software environment. Attachments in JNET are constraints over arbitrary Java objects, which are defined using Java code, at runtime, with no changes to the JNET source code.

  4. 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

  5. Infrared Kuiper Belt Constraints

    SciTech Connect

    Teplitz, V.L.; Stern, S.A.; Anderson, J.D.; Rosenbaum, D.; Scalise, R.J.; Wentzler, P.

    1999-05-01

    We compute the temperature and IR signal of particles of radius {ital a} and albedo {alpha} at heliocentric distance {ital R}, taking into account the emissivity effect, and give an interpolating formula for the result. We compare with analyses of {ital COBE} DIRBE data by others (including recent detection of the cosmic IR background) for various values of heliocentric distance {ital R}, particle radius {ital a}, and particle albedo {alpha}. We then apply these results to a recently developed picture of the Kuiper belt as a two-sector disk with a nearby, low-density sector (40{lt}R{lt}50{endash}90 AU) and a more distant sector with a higher density. We consider the case in which passage through a molecular cloud essentially cleans the solar system of dust. We apply a simple model of dust production by comet collisions and removal by the Poynting-Robertson effect to find limits on total and dust masses in the near and far sectors as a function of time since such a passage. Finally, we compare Kuiper belt IR spectra for various parameter values. Results of this work include: (1) numerical limits on Kuiper belt dust as a function of ({ital R}, {ital a}, {alpha}) on the basis of four alternative sets of constraints, including those following from recent discovery of the cosmic IR background by Hauser et al.; (2) application to the two-sector Kuiper belt model, finding mass limits and spectrum shape for different values of relevant parameters including dependence on time elapsed since last passage through a molecular cloud cleared the outer solar system of dust; and (3) potential use of spectral information to determine time since last passage of the Sun through a giant molecular cloud. {copyright} {ital {copyright} 1999.} {ital The American Astronomical Society}

  6. 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.

  7. 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

  8. Path following control of planar snake robots using virtual holonomic constraints: theory and experiments.

    PubMed

    Rezapour, Ehsan; Pettersen, Kristin Y; Liljebäck, Pål; Gravdahl, Jan T; Kelasidi, Eleni

    This paper considers path following control of planar snake robots using virtual holonomic constraints. In order to present a model-based path following control design for the snake robot, we first derive the Euler-Lagrange equations of motion of the system. Subsequently, we define geometric relations among the generalized coordinates of the system, using the method of virtual holonomic constraints. These appropriately defined constraints shape the geometry of a constraint manifold for the system, which is a submanifold of the configuration space of the robot. Furthermore, we show that the constraint manifold can be made invariant by a suitable choice of feedback. In particular, we analytically design a smooth feedback control law to exponentially stabilize the constraint manifold. We show that enforcing the appropriately defined virtual holonomic constraints for the configuration variables implies that the robot converges to and follows a desired geometric path. Numerical simulations and experimental results are presented to validate the theoretical approach.

  9. 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.

  10. Maximum life spiral bevel reduction design

    NASA Astrophysics Data System (ADS)

    Savage, M.; Prasanna, M. G.; Coe, H. H.

    1992-07-01

    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.

  11. Constraint-based stereo matching

    NASA Technical Reports Server (NTRS)

    Kuan, D. T.

    1987-01-01

    The major difficulty in stereo vision is the correspondence problem that requires matching features in two stereo images. Researchers describe a constraint-based stereo matching technique using local geometric constraints among edge segments to limit the search space and to resolve matching ambiguity. Edge segments are used as image features for stereo matching. Epipolar constraint and individual edge properties are used to determine possible initial matches between edge segments in a stereo image pair. Local edge geometric attributes such as continuity, junction structure, and edge neighborhood relations are used as constraints to guide the stereo matching process. The result is a locally consistent set of edge segment correspondences between stereo images. These locally consistent matches are used to generate higher-level hypotheses on extended edge segments and junctions to form more global contexts to achieve global consistency.

  12. 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.

  13. Additional notes on clinical repeated-dose pharmacokinetic trials applying a peak-and-trough sampling design to estimate oral clearance.

    PubMed

    Takaai, Mari; Kayano, Yuichiro; Shimizu, Takako; Taguchi, Masato; Hashimoto, Yukiya

    2008-01-01

    In the previous study, we performed a simulation of a clinical pharmacokinetic trial, in which blood was sampled at two time points corresponding to the peak concentration (C(peak)) and trough concentration (C(trough)) following repetitive oral administration at the dose, D, and dosing interval, tau. The approximate oral clearance (CL/F(approx)), estimated as 2 x D/(C(peak) x tau+C(trough) x tau), is accurate for drugs with an elimination half-life comparative to or longer than tau; however, it was suggested that we might not use CL/F(approx) for drugs with a considerably short elimination half-life relative to tau. In the present study, we evaluated the accuracy of the alternative oral clearance (CL/F(exp)) estimated by the simple monoexponential model. In contrast to CL/F(approx), CL/F(exp) was accurate for drugs with a short elimination half-life relative to tau. The present finding in conjunction with our previous study suggested that the peak-and-trough sampling design is promising for the clinical repeated-dose pharmacokinetic trial for drugs with not only slow but also rapid elimination from the body. We think that the accuracy and precision of the two analysis methods to estimate oral clearance (CL/F(approx) and CL/F(exp)) for a target drug should be evaluated carefully before and after a real clinical trial.

  14. 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.

  15. A Low-Cost Environmental Monitoring System: How to Prevent Systematic Errors in the Design Phase through the Combined Use of Additive Manufacturing and Thermographic Techniques.

    PubMed

    Salamone, Francesco; Danza, Ludovico; Meroni, Italo; Pollastro, Maria Cristina

    2017-04-11

    nEMoS (nano Environmental Monitoring System) is a 3D-printed device built following the Do-It-Yourself (DIY) approach. It can be connected to the web and it can be used to assess indoor environmental quality (IEQ). It is built using some low-cost sensors connected to an Arduino microcontroller board. The device is assembled in a small-sized case and both thermohygrometric sensors used to measure the air temperature and relative humidity, and the globe thermometer used to measure the radiant temperature, can be subject to thermal effects due to overheating of some nearby components. A thermographic analysis was made to rule out this possibility. The paper shows how the pervasive technique of additive manufacturing can be combined with the more traditional thermographic techniques to redesign the case and to verify the accuracy of the optimized system in order to prevent instrumental systematic errors in terms of the difference between experimental and actual values of the above-mentioned environmental parameters.

  16. Infill Optimization for Additive Manufacturing -- Approaching Bone-like Porous Structures.

    PubMed

    Wu, Jun; Aage, Niels; Westermann, Ruediger; Sigmund, Ole

    2017-01-23

    Porous structures such as trabecular bone are widely seen in nature. These structures are lightweight and exhibit strong mechanical properties. In this paper, we present a method to generate bone-like porous structures as lightweight infill for additive manufacturing. Our method builds upon and extends voxel-wise topology optimization. In particular, for the purpose of generating sparse yet stable structures distributed in the interior of a given shape, we propose upper bounds on the localized material volume in the proximity of each voxel in the design domain. We then aggregate the local per-voxel constraints by their p-norm into an equivalent global constraint, in order to facilitate an efficient optimization process. Implemented on a high-resolution topology optimization framework, our results demonstrate mechanically optimized, detailed porous structures which mimic those found in nature. We further show variants of the optimized structures subject to different design specifications, and we analyze the optimality and robustness of the obtained structures.

  17. 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

  18. Thermodynamic constraints for biochemical networks.

    PubMed

    Beard, Daniel A; Babson, Eric; Curtis, Edward; Qian, Hong

    2004-06-07

    The constraint-based approach to analysis of biochemical systems has emerged as a useful tool for rational metabolic engineering. Flux balance analysis (FBA) is based on the constraint of mass conservation; energy balance analysis (EBA) is based on non-equilibrium thermodynamics. The power of these approaches lies in the fact that the constraints are based on physical laws, and do not make use of unknown parameters. Here, we show that the network structure (i.e. the stoichiometric matrix) alone provides a system of constraints on the fluxes in a biochemical network which are feasible according to both mass balance and the laws of thermodynamics. A realistic example shows that these constraints can be sufficient for deriving unambiguous, biologically meaningful results. The thermodynamic constraints are obtained by comparing of the sign pattern of the flux vector to the sign patterns of the cycles of the internal cycle space via connection between stoichiometric network theory (SNT) and the mathematical theory of oriented matroids.

  19. Optimal design of imperfect, anisotropic, ring-stiffened cylinders under combined loads

    NASA Technical Reports Server (NTRS)

    Ley, Robert P.; Gurdal, Zafer; Johnson, Eric R.

    1993-01-01

    Development of an algorithm to perform the optimal sizing of buckling resistant, imperfect, anisotropic ring-stiffened cylinders subjected to axial compression, torsion, and internal pressure is presented. The enforcement of stability constraints is treated in a way that does not require any eigenvalue analysis. Assumption of criticality of these stability constraints during the optimal sizing of the cylinders produced designs that nevertheless satisfied all of the stress constraints as well as the stability constraints. Case studies performed using a combination of penalty function and feasible direction optimization methods indicate that the presence of the axisymmetric initial imperfection in the cylinder wall can significantly affect the optimal designs. Weight savings associated with the addition of two rings to the unstiffened cylinder and/or the addition of internal pressure is substantial when torsion makes up a significant fraction of the combined load state.

  20. 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

  1. Cosmological constraints on a decomposed Chaplygin gas

    NASA Astrophysics Data System (ADS)

    Wang, Yuting; Wands, David; Xu, Lixin; De-Santiago, Josue; Hojjati, Alireza

    2013-04-01

    Any unified dark matter cosmology can be decomposed into dark matter interacting with vacuum energy, without introducing any additional degrees of freedom. We present observational constraints on an interacting vacuum plus dark energy corresponding to a generalized Chaplygin gas cosmology. We consider two distinct models for the interaction leading to either a barotropic equation of state or dark matter that follows geodesics, corresponding to a rest-frame sound speed equal to the adiabatic sound speed or zero sound speed, respectively. For the barotropic model, the most stringent constraint on α comes from the combination of CMB+SNIa+LSS(m) gives α<5.66×10-6 at the 95% confidence level, which indicates that the barotropic model must be extremely close to the ΛCDM cosmology. For the case where the dark matter follows geodesics, perturbations have zero sound speed, and CMB+SNIa+gISW then gives the much weaker constraint -0.15<α<0.26 at the 95% confidence level.

  2. 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

  3. 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.

  4. 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.

  5. 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

  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. Large-Constraint-Length, Fast Viterbi Decoder

    NASA Technical Reports Server (NTRS)

    Collins, O.; Dolinar, S.; Hsu, In-Shek; Pollara, F.; Olson, E.; Statman, J.; Zimmerman, G.

    1990-01-01

    Scheme for efficient interconnection makes VLSI design feasible. Concept for fast Viterbi decoder provides for processing of convolutional codes of constraint length K up to 15 and rates of 1/2 to 1/6. Fully parallel (but bit-serial) architecture developed for decoder of K = 7 implemented in single dedicated VLSI circuit chip. Contains six major functional blocks. VLSI circuits perform branch metric computations, add-compare-select operations, and then store decisions in traceback memory. Traceback processor reads appropriate memory locations and puts out decoded bits. Used as building block for decoders of larger K.

  8. 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.

  9. 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.

  10. The relationship between threat appraisal and social constraints in cancer survivors and their spouses.

    PubMed

    Herzer, Michele; Zakowski, Sandra G; Flanigan, Robert; Johnson, Peter

    2006-12-01

    : Social constraints stem from unsupportive social environments and are associated with reluctance to discuss stressor-related thoughts and feelings. Support deterioration and erosion models provide a framework for explaining how a cancer patient's threat appraisal contributes to a spouse's inadvertent constraint on the patient's emotional expression. Also, based on social comparison theory and the convoy model, a discrepancy in threat appraisal between patient and spouse may create social constraints. Contrary to social cognitive processing theories, we hypothesized that threat appraisals may be an antecedent of social constraints, rather than a consequence. Cancer patients (n=75) and their spouses (n=75) completed questionnaires assessing cancer-related threat appraisals and perceived spousal social constraints at two time points. Cross-lagged panel design results suggested that patient appraisal precedes and predicts patients' perception of social constraints. However, patient and spouse appraisals did not significantly interact in predicting spousal constraints. Limitations and implications are discussed.

  11. Multisensory constraints on awareness.

    PubMed

    Deroy, Ophelia; Chen, Yi-Chuan; Spence, Charles

    2014-05-05

    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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Optimizing sensor placement using predictive geospatial analytics, the physical environment, and surveillance constraints

    NASA Astrophysics Data System (ADS)

    Schmidt, Greg; Witham, Brandon; Valore, Jason; Holland, Ben; Dalton, Jason

    2012-06-01

    Military, police, and industrial surveillance operations could benefit from having sensors deployed in configurations that maximize collection capability. We describe a surveillance planning approach that optimizes sensor placements to collect information about targets of interest by using information from predictive geospatial analytics, the physical environment, and surveillance constraints. We designed a tool that accounts for multiple sensor aspects-collection footprints, groupings, and characteristics; multiple optimization objectives-surveillance requirements and predicted threats; and multiple constraints-sensing, physical environment (including terrain), and geographic surveillance constraints. The tool uses a discrete grid model to keep track of geographic sensing objectives and constraints, and from these, estimate probabilities for collection containment and detection. We devised an evolutionary algorithm and polynomial time approximation schemes (PTAS) to optimize the tool variables above to generate the positions and aspect for a network of sensors. We also designed algorithms to coordinate a mixture of sensors with different competing objectives, competing constraints, couplings, and proximity constraints.

  17. Design.

    ERIC Educational Resources Information Center

    Online-Offline, 1998

    1998-01-01

    Provides an annotated bibliography of resources on this month's theme "Design" for K-8 language arts, art and architecture, music and dance, science, math, social studies, health, and physical education. Includes Web sites, CD-ROMs and software, videos, books, audiotapes, magazines, professional resources and classroom activities.…

  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. Incorporation of phonetic constraints in acoustic-to-articulatory inversion.

    PubMed

    Potard, Blaise; Laprie, Yves; Ouni, Slim

    2008-04-01

    This study investigates the use of constraints upon articulatory parameters in the context of acoustic-to-articulatory inversion. These speaker independent constraints, referred to as phonetic constraints, were derived from standard phonetic knowledge for French vowels and express authorized domains for one or several articulatory parameters. They were experimented on in an existing inversion framework that utilizes Maeda's articulatory model and a hypercubic articulatory-acoustic table. Phonetic constraints give rise to a phonetic score rendering the phonetic consistency of vocal tract shapes recovered by inversion. Inversion has been applied to vowels articulated by a speaker whose corresponding x-ray images are also available. Constraints were evaluated by measuring the distance between vocal tract shapes recovered through inversion to real vocal tract shapes obtained from x-ray images, by investigating the spreading of inverse solutions in terms of place of articulation and constriction degree, and finally by studying the articulatory variability. Results show that these constraints capture interdependencies and synergies between speech articulators and favor vocal tract shapes close to those realized by the human speaker. In addition, this study also provides how acoustic-to-articulatory inversion can be used to explore acoustical and compensatory articulatory properties of an articulatory model.

  20. Democratic constraints on demographic policy.

    PubMed

    Grigsby, J S

    1984-01-01

    The discussion compares the population policies adopted in Sweden during the 1930s to raise fertiity and the policies considered in the US during the 1970s in response to the high fertility experienced in the 1950s. Both sets of policies recommended increased availability of birth control, more liberal abortion laws, and greater employment opportunities for women. It becomes evident that the constraints imposed by a democratic system of government translate into policy recommendations that place individual freedom of choice and equal opportunity for all citizens as higher goals than any specific demographic target. Consequently, the population commissions of Sweden and the US made similar suggestions on how to resolve their opposite demographic problems. The demographic situations in the 2 nations were antipodal, and the countries also had very different social climates. This additional disparity was insufficient to counterbalance the apparently overwhelming influence of the democratic political systems in making virtually identical policy recommendations. Yet, the contrasting social climates of Sweden in 1935 and the US in 1970-72 may explain the different reactions each commission received. In terms of the responses by both citizens and government officials to the commissions' reports, the Swedish commission was more successful. Practically all of their recommendations were enthusiastically received and quickly adopted by the Swedish Riksdag. Yet, when the criterion for success becomes whether or not a demographic target was met, it increased in the 1940s and then dropped again while the same social policies were in effect. Even before the US commission began its study, fertility in the US had fallen and continues to remain low. These findings suggest that commissions in democratic countries will most likely never recommend dramatic measures in population policy. Thus, it is questionable whether such commissions in democratic nations will totally fulfill the