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Sample records for advanced control theory

  1. Advanced stability theory analyses for laminar flow control

    NASA Technical Reports Server (NTRS)

    Orszag, S. A.

    1980-01-01

    Recent developments of the SALLY computer code for stability analysis of laminar flow control wings are summarized. Extensions of SALLY to study three dimensional compressible flows, nonparallel and nonlinear effects are discussed.

  2. Control Theory.

    ERIC Educational Resources Information Center

    Toso, Robert B.

    2000-01-01

    Inspired by William Glasser's Reality Therapy ideas, Control Theory (CT) is a disciplinary approach that stresses people's ability to control only their own behavior, based on internal motivations to satisfy five basic needs. At one North Dakota high school, CT-trained teachers are the program's best recruiters. (MLH)

  3. Advanced Quality Control Theory for Training and Education: A Guide to Optimizing Training and Education Efforts

    ERIC Educational Resources Information Center

    Heppler, Brad

    2008-01-01

    This is a book about quality and how to control quality through deliberate actions on the part of the professionals developing and implementing the instances of instruction available at an organization. Quality control theory favors no particular learning philosophy and is only directed towards aspects of how, what, where and when measurements are…

  4. Recent Advances In Structural Vibration And Failure Mode Control In Mainland China: Theory, Experiments And Applications

    NASA Astrophysics Data System (ADS)

    Li, Hui; Ou, Jinping

    2008-07-01

    A number of researchers have been focused on structural vibration control in the past three decades over the world and fruit achievements have been made. This paper introduces the recent advances in structural vibration control including passive, active and semiactive control in mainland China. Additionally, the co-author extends the structural vibration control to failure mode control. The research on the failure mode control is also involved in this paper. For passive control, this paper introduces full scale tests of buckling-restrained braces conducted to investigate the performance of the dampers and the second-editor of the Code of Seismic Design for Buildings. For active control, this paper introduces the HMD system for wind-induced vibration control of the Guangzhou TV tower. For semiactive control, the smart damping devices, algorithms for semi-active control, design methods and applications of semi-active control for structures are introduced in this paper. The failure mode control for bridges is also introduced.

  5. Recent Advances In Structural Vibration And Failure Mode Control In Mainland China: Theory, Experiments And Applications

    SciTech Connect

    Li Hui; Ou Jinping

    2008-07-08

    A number of researchers have been focused on structural vibration control in the past three decades over the world and fruit achievements have been made. This paper introduces the recent advances in structural vibration control including passive, active and semiactive control in mainland China. Additionally, the co-author extends the structural vibration control to failure mode control. The research on the failure mode control is also involved in this paper. For passive control, this paper introduces full scale tests of buckling-restrained braces conducted to investigate the performance of the dampers and the second-editor of the Code of Seismic Design for Buildings. For active control, this paper introduces the HMD system for wind-induced vibration control of the Guangzhou TV tower. For semiactive control, the smart damping devices, algorithms for semi-active control, design methods and applications of semi-active control for structures are introduced in this paper. The failure mode control for bridges is also introduced.

  6. Advances in adaptive control theory: Gradient- and derivative-free approaches

    NASA Astrophysics Data System (ADS)

    Yucelen, Tansel

    In this dissertation, we present new approaches to improve standard designs in adaptive control theory, and novel adaptive control architectures. We first present a novel Kalman filter based approach for approximately enforcing a linear constraint in standard adaptive control design. One application is that this leads to alternative forms for well known modification terms such as e-modification. In addition, it leads to smaller tracking errors without incurring significant oscillations in the system response and without requiring high modification gain. We derive alternative forms of e- and adaptive loop recovery (ALR-) modifications. Next, we show how to use Kalman filter optimization to derive a novel adaptation law. This results in an optimization-based time-varying adaptation gain that reduces the need for adaptation gain tuning. A second major contribution of this dissertation is the development of a novel derivative-free, delayed weight update law for adaptive control. The assumption of constant unknown ideal weights is relaxed to the existence of time-varying weights, such that fast and possibly discontinuous variation in weights are allowed. This approach is particulary advantageous for applications to systems that can undergo a sudden change in dynamics, such as might be due to reconfiguration, deployment of a payload, docking, or structural damage, and for rejection of external disturbance processes. As a third and final contribution, we develop a novel approach for extending all the methods developed in this dissertation to the case of output feedback. The approach is developed only for the case of derivative-free adaptive control, and the extension of the other approaches developed previously for the state feedback case to output feedback is left as a future research topic. The proposed approaches of this dissertation are illustrated in both simulation and flight test.

  7. ADVANCES IN IMPEDANCE THEORY

    SciTech Connect

    Stupakov, G.; /SLAC

    2009-06-05

    We review recent progress in the following areas of the impedance theory: calculation of impedance of tapers and small angle collimators; optical approximation and parabolic equation for the high-frequency impedance; impedance due to resistive inserts in a perfectly conducting pipe.

  8. Development of advanced stability theory suction prediction techniques for laminar flow control. [on swept wings

    NASA Technical Reports Server (NTRS)

    Srokowski, A. J.

    1978-01-01

    The problem of obtaining accurate estimates of suction requirements on swept laminar flow control wings was discussed. A fast accurate computer code developed to predict suction requirements by integrating disturbance amplification rates was described. Assumptions and approximations used in the present computer code are examined in light of flow conditions on the swept wing which may limit their validity.

  9. Advances in lattice gauge theory

    SciTech Connect

    Duke, D.W.; Owens, J.F.

    1985-01-01

    This book presents papers on advances in lattice gauge theory. Topics covered include fermion Monte Carlo algorithms, portrait of a proton, critical behavior in QCD, the standard Higgs-model on the lattice, analytic calculation of mass gaps, and simulation of discrete Euclidean quantum gravity.

  10. Advances in Process Control.

    ERIC Educational Resources Information Center

    Morrison, David L.; And Others

    1982-01-01

    Advances in electronics and computer science have enabled industries (pulp/paper, iron/steel, petroleum/chemical) to attain better control of their processes with resulting increases in quality, productivity, profitability, and compliance with government regulations. (JN)

  11. Advanced Aerodynamic Control Effectors

    NASA Technical Reports Server (NTRS)

    Wood, Richard M.; Bauer, Steven X. S.

    1999-01-01

    A 1990 research program that focused on the development of advanced aerodynamic control effectors (AACE) for military aircraft has been reviewed and summarized. Data are presented for advanced planform, flow control, and surface contouring technologies. The data show significant increases in lift, reductions in drag, and increased control power, compared to typical aerodynamic designs. The results presented also highlighted the importance of planform selection in the design of a control effector suite. Planform data showed that dramatic increases in lift (greater than 25%) can be achieved with multiple wings and a sawtooth forebody. Passive porosity and micro drag generator control effector data showed control power levels exceeding that available from typical effectors (moving surfaces). Application of an advanced planform to a tailless concept showed benefits of similar magnitude as those observed in the generic studies.

  12. Splines and control theory

    NASA Technical Reports Server (NTRS)

    Zhang, Zhimin; Tomlinson, John; Martin, Clyde

    1994-01-01

    In this work, the relationship between splines and the control theory has been analyzed. We show that spline functions can be constructed naturally from the control theory. By establishing a framework based on control theory, we provide a simple and systematic way to construct splines. We have constructed the traditional spline functions including the polynomial splines and the classical exponential spline. We have also discovered some new spline functions such as trigonometric splines and the combination of polynomial, exponential and trigonometric splines. The method proposed in this paper is easy to implement. Some numerical experiments are performed to investigate properties of different spline approximations.

  13. Advanced Wavefront Control Techniques

    SciTech Connect

    Olivier, S S; Brase, J M; Avicola, K; Thompson, C A; Kartz, M W; Winters, S; Hartley, R; Wihelmsen, J; Dowla, F V; Carrano, C J; Bauman, B J; Pennington, D M; Lande, D; Sawvel, R M; Silva, D A; Cooke, J B; Brown, C G

    2001-02-21

    this project, work was performed in four areas (1) advanced modeling tools for deformable mirrors (2) low-order wavefront correctors with Alvarez lenses, (3) a direct phase measuring heterdyne wavefront sensor, and (4) high-spatial-frequency wavefront control using spatial light modulators.

  14. Advances in reversed field pinch theory and computation

    SciTech Connect

    Schnack, D.D.; Ho, Y.L.; Carreras, B.A.; Sidikman, K.; Craddock, G.G.; Mattor, N.; Nebel, R.A.; Prager, S.C.; Terry, P.W.; Zita, E.J.

    1992-12-31

    Advances in theory and computations related to the reversed field pinch (RFP) are presented. These are: (1) the effect of the dynamo on thermal transport; (2) a theory of ion heating due to dynamo fluctuations; (3) studies of active and passive feedback schemes for controlling dynamo fluctuations; and (4) an analytic model for coupled g-mode and rippling turbulence in the RFP edge.

  15. On Restructurable Control System Theory

    NASA Technical Reports Server (NTRS)

    Athans, M.

    1983-01-01

    The state of stochastic system and control theory as it impacts restructurable control issues is addressed. The multivariable characteristics of the control problem are addressed. The failure detection/identification problem is discussed as a multi-hypothesis testing problem. Control strategy reconfiguration, static multivariable controls, static failure hypothesis testing, dynamic multivariable controls, fault-tolerant control theory, dynamic hypothesis testing, generalized likelihood ratio (GLR) methods, and adaptive control are discussed.

  16. Construct Validity: Advances in Theory and Methodology

    PubMed Central

    Strauss, Milton E.; Smith, Gregory T.

    2008-01-01

    Measures of psychological constructs are validated by testing whether they relate to measures of other constructs as specified by theory. Each test of relations between measures reflects on the validity of both the measures and the theory driving the test. Construct validation concerns the simultaneous process of measure and theory validation. In this chapter, we review the recent history of validation efforts in clinical psychological science that has led to this perspective, and we review five recent advances in validation theory and methodology of importance for clinical researchers. These are: the emergence of nonjustificationist philosophy of science; an increasing appreciation for theory and the need for informative tests of construct validity; valid construct representation in experimental psychopathology; the need to avoid representing multidimensional constructs with a single score; and the emergence of effective new statistical tools for the evaluation of convergent and discriminant validity. PMID:19086835

  17. ADVANCED SULFUR CONTROL CONCEPTS

    SciTech Connect

    Apostolos A. Nikolopoulos; Santosh K. Gangwal; William J. McMichael; Jeffrey W. Portzer

    2003-01-01

    Conventional sulfur removal in integrated gasification combined cycle (IGCC) power plants involves numerous steps: COS (carbonyl sulfide) hydrolysis, amine scrubbing/regeneration, Claus process, and tail-gas treatment. Advanced sulfur removal in IGCC systems involves typically the use of zinc oxide-based sorbents. The sulfides sorbent is regenerated using dilute air to produce a dilute SO{sub 2} (sulfur dioxide) tail gas. Under previous contracts the highly effective first generation Direct Sulfur Recovery Process (DSRP) for catalytic reduction of this SO{sub 2} tail gas to elemental sulfur was developed. This process is currently undergoing field-testing. In this project, advanced concepts were evaluated to reduce the number of unit operations in sulfur removal and recovery. Substantial effort was directed towards developing sorbents that could be directly regenerated to elemental sulfur in an Advanced Hot Gas Process (AHGP). Development of this process has been described in detail in Appendices A-F. RTI began the development of the Single-step Sulfur Recovery Process (SSRP) to eliminate the use of sorbents and multiple reactors in sulfur removal and recovery. This process showed promising preliminary results and thus further process development of AHGP was abandoned in favor of SSRP. The SSRP is a direct Claus process that consists of injecting SO{sub 2} directly into the quenched coal gas from a coal gasifier, and reacting the H{sub 2}S-SO{sub 2} mixture over a selective catalyst to both remove and recover sulfur in a single step. The process is conducted at gasifier pressure and 125 to 160 C. The proposed commercial embodiment of the SSRP involves a liquid phase of molten sulfur with dispersed catalyst in a slurry bubble-column reactor (SBCR).

  18. Advanced Theory of Deep Geomagnetic Sounding

    NASA Astrophysics Data System (ADS)

    Chave, Alan D.

    Advanced Theory of Deep Geomagnetic Sounding is a specialized treatise that covers recent work, mostly from the Soviet Union, on the theory, analysis, and interpretation of natural source electromagnetic induction processes in complex geological structures, with an emphasis on subsurface conductive anomalies. The scope of the book is limited, as suggested by the title, and the authors stress the application of electromagnetic principles to the study of regional geology and deep earth structure rather than surface exploration. The book is clearly aimed at the practicing specialist rather than the graduate student attempting to learn about the broader field of electromagnetic geophysics.

  19. Advances in infection control

    PubMed Central

    Marra, Alexandre Rodrigues

    2016-01-01

    ABSTRACT Several initiatives took place in recent years in relation to nosocomial infection control in order to increase patient safety. Some of these initiatives will be commented in this brief review. PMID:27074240

  20. Control Theory and Statistical Generalizations.

    ERIC Educational Resources Information Center

    Powers, William T.

    1990-01-01

    Contrasts modeling methods in control theory to the methods of statistical generalizations in empirical studies of human or animal behavior. Presents a computer simulation that predicts behavior based on variables (effort and rewards) determined by the invariable (desired reward). Argues that control theory methods better reflect relationships to…

  1. Prospects for Advanced RF Theory and Modeling

    SciTech Connect

    Batchelor, D.B.

    1999-04-12

    This paper represents an attempt to express in print the contents of a rather philosophical review talk. The charge for the talk was not to summarize the present status of the field and what we can do, but to assess what we will need to do in the future and where the gaps are in fulfilling these needs. The objective was to be complete, covering all aspects of theory and modeling in all frequency regimes, although in the end the talk mainly focussed on the ion cyclotron range of frequencies (ICRF). In choosing which areas to develop, it is important to keep in mind who the customers for RF modeling are likely to be and what sorts of tasks they will need for RF to do. This occupies the first part of the paper. Then we examine each of the elements of a complete RF theory and try to identify the kinds of advances needed.

  2. Delayed coker fractionator advanced control

    SciTech Connect

    Jaisinghani, R.; Minter, B. ); Tica, A.; Puglesi, A.; Ojeda, R. )

    1993-08-01

    In a delayed coking process, as coke drum switches are made, rapid changes occur in both the fractionator feed rate and composition. With conventional control, it is not unusual to see long transient behavior of large swings in both quality and flowrates of coker gas oils. This can extract a heavy economic toll, not only in coker operation, but in the operation of downstream units as the upset is propagated. An advanced process control application (APC) was recently implemented on the coker fractionator at the Yacimentos Petroliferos Fiscales (YPF), Lujan de Cuyo Refinery, in Mendoza, Argentina. This coker fractionator control design was unique as it handled two different operating objectives: control of product qualities via tower temperature profile during normal operation and control of gas oil product flow ratio during drum switch. This combination of control objectives in one multivariable predictive control program was achieved by including special logic to decouple the individual tuning requirements. Also, additional logic was included to unambiguously detect and identify drum switch and drum steam out as discrete events within 30 seconds of their actual occurrence. These discrete events were then used as disturbance variables to minimize fractionator transient behavior. As a performance measure, the overhead temperature was controlled within 2 C to 2.5 C of its target, gas oil flows were stabilized during drum switches and steam generation via pump around was maximized. Overall, implementing advanced control for the delayed coker fractionator resulted in substantial benefits from product quality control, product flow control and minimized energy consumption.

  3. Advanced flight control system study

    NASA Technical Reports Server (NTRS)

    Mcgough, J.; Moses, K.; Klafin, J. F.

    1982-01-01

    The architecture, requirements, and system elements of an ultrareliable, advanced flight control system are described. The basic criteria are functional reliability of 10 to the minus 10 power/hour of flight and only 6 month scheduled maintenance. A distributed system architecture is described, including a multiplexed communication system, reliable bus controller, the use of skewed sensor arrays, and actuator interfaces. Test bed and flight evaluation program are proposed.

  4. Rotor Performance at High Advance Ratio: Theory versus Test

    NASA Technical Reports Server (NTRS)

    Harris, Franklin D.

    2008-01-01

    Five analytical tools have been used to study rotor performance at high advance ratio. One is representative of autogyro rotor theory in 1934 and four are representative of helicopter rotor theory in 2008. The five theories are measured against three sets of well documented, full-scale, isolated rotor performance experiments. The major finding of this study is that the decades spent by many rotorcraft theoreticians to improve prediction of basic rotor aerodynamic performance has paid off. This payoff, illustrated by comparing the CAMRAD II comprehensive code and Wheatley & Bailey theory to H-34 test data, shows that rational rotor lift to drag ratios are now predictable. The 1934 theory predicted L/D ratios as high as 15. CAMRAD II predictions compared well with H-34 test data having L/D ratios more on the order of 7 to 9. However, the detailed examination of the selected codes compared to H-34 test data indicates that not one of the codes can predict to engineering accuracy above an advance ratio of 0.62 the control positions and shaft angle of attack required for a given lift. There is no full-scale rotor performance data available for advance ratios above 1.0 and extrapolation of currently available data to advance ratios on the order of 2.0 is unreasonable despite the needs of future rotorcraft. Therefore, it is recommended that an overly strong full-scale rotor blade set be obtained and tested in a suitable wind tunnel to at least an advance ratio of 2.5. A tail rotor from a Sikorsky CH-53 or other large single rotor helicopter should be adequate for this exploratory experiment.

  5. ADVANCED EMISSIONS CONTROL DEVELOPMENT PROGRAM

    SciTech Connect

    G.A. Farthing

    2001-02-06

    The primary objective of the Advanced Emissions Control Development Program (AECDP) is to develop practical, cost-effective strategies for reducing the emissions of hazardous air pollutants (HAPs, or air toxics) from coal-fired boilers. The project goal is to effectively control air toxic emissions through the use of conventional flue gas cleanup equipment such as electrostatic precipitators (ESPs), fabric filters (baghouses), and wet flue gas desulfurization (WFGD) systems. Development work initially concentrated on the capture of trace metals, fine particulate, hydrogen chloride, and hydrogen fluoride. Recent work has focused almost exclusively on the control of mercury emissions.

  6. Advanced Emissions Control Development Program

    SciTech Connect

    G. A. Farthing; G. T. Amrhein; G. A. Kudlac; D. A. Yurchison; D. K. McDonald; M. G. Milobowski

    2001-03-31

    The primary objective of the Advanced Emissions Control Development Program (AECDP) is to develop practical, cost-effective strategies for reducing the emissions of hazardous air pollutants (HAPs, or air toxics) from coal-fired boilers. This objective is being met by identifying ways to effectively control air toxic emissions through the use of conventional flue gas cleanup equipment such as electrostatic precipitators (ESPs), fabric filters (fabric filters), and wet flue gas desulfurization (wet FGD) systems. Development work initially concentrated on the capture of trace metals, hydrogen chloride, and hydrogen fluoride. Recent work has focused almost exclusively on the control of mercury emissions.

  7. Advanced flight control system study

    NASA Technical Reports Server (NTRS)

    Hartmann, G. L.; Wall, J. E., Jr.; Rang, E. R.; Lee, H. P.; Schulte, R. W.; Ng, W. K.

    1982-01-01

    A fly by wire flight control system architecture designed for high reliability includes spare sensor and computer elements to permit safe dispatch with failed elements, thereby reducing unscheduled maintenance. A methodology capable of demonstrating that the architecture does achieve the predicted performance characteristics consists of a hierarchy of activities ranging from analytical calculations of system reliability and formal methods of software verification to iron bird testing followed by flight evaluation. Interfacing this architecture to the Lockheed S-3A aircraft for flight test is discussed. This testbed vehicle can be expanded to support flight experiments in advanced aerodynamics, electromechanical actuators, secondary power systems, flight management, new displays, and air traffic control concepts.

  8. Advanced gray rod control assembly

    DOEpatents

    Drudy, Keith J; Carlson, William R; Conner, Michael E; Goldenfield, Mark; Hone, Michael J; Long, Jr., Carroll J; Parkinson, Jerod; Pomirleanu, Radu O

    2013-09-17

    An advanced gray rod control assembly (GRCA) for a nuclear reactor. The GRCA provides controlled insertion of gray rod assemblies into the reactor, thereby controlling the rate of power produced by the reactor and providing reactivity control at full power. Each gray rod assembly includes an elongated tubular member, a primary neutron-absorber disposed within the tubular member said neutron-absorber comprising an absorber material, preferably tungsten, having a 2200 m/s neutron absorption microscopic capture cross-section of from 10 to 30 barns. An internal support tube can be positioned between the primary absorber and the tubular member as a secondary absorber to enhance neutron absorption, absorber depletion, assembly weight, and assembly heat transfer characteristics.

  9. The Role of Modern Control Theory in the Design of Controls for Aircraft Turbine Engines

    NASA Technical Reports Server (NTRS)

    Zeller, J.; Lehtinen, B.; Merrill, W.

    1982-01-01

    Accomplishments in applying Modern Control Theory to the design of controls for advanced aircraft turbine engines were reviewed. The results of successful research programs are discussed. Ongoing programs as well as planned or recommended future thrusts are also discussed.

  10. Aerodynamic design via control theory

    NASA Technical Reports Server (NTRS)

    Jameson, Antony

    1988-01-01

    The question of how to modify aerodynamic design in order to improve performance is addressed. Representative examples are given to demonstrate the computational feasibility of using control theory for such a purpose. An introduction and historical survey of the subject is included.

  11. Advanced nuclear plant control complex

    DOEpatents

    Scarola, Kenneth; Jamison, David S.; Manazir, Richard M.; Rescorl, Robert L.; Harmon, Daryl L.

    1993-01-01

    An advanced control room complex for a nuclear power plant, including a discrete indicator and alarm system (72) which is nuclear qualified for rapid response to changes in plant parameters and a component control system (64) which together provide a discrete monitoring and control capability at a panel (14-22, 26, 28) in the control room (10). A separate data processing system (70), which need not be nuclear qualified, provides integrated and overview information to the control room and to each panel, through CRTs (84) and a large, overhead integrated process status overview board (24). The discrete indicator and alarm system (72) and the data processing system (70) receive inputs from common plant sensors and validate the sensor outputs to arrive at a representative value of the parameter for use by the operator during both normal and accident conditions, thereby avoiding the need for him to assimilate data from each sensor individually. The integrated process status board (24) is at the apex of an information hierarchy that extends through four levels and provides access at each panel to the full display hierarchy. The control room panels are preferably of a modular construction, permitting the definition of inputs and outputs, the man machine interface, and the plant specific algorithms, to proceed in parallel with the fabrication of the panels, the installation of the equipment and the generic testing thereof.

  12. Advanced Emissions Control Development Program

    SciTech Connect

    A.P.Evans; K.E. Redinger; M.J. Holmes

    1998-04-01

    The objective of the Advanced Emissions Control Development Program (AECDP) is to develop practical, cost-effective strategies for reducing the emissions of air toxics from coal-fired boilers. Ideally, the project aim is to effectively control air toxic emissions through the use of conventional flue gas cleanup equipment such as electrostatic precipitators (ESPS), fabric filters (baghouse), and wet flue gas desulfurization. Development work to date has concentrated on the capture of mercury, other trace metals, fine particulate and hydrogen chloride. Following the construction and evaluation of a representative air toxics test facility in Phase I, Phase II focused on the evaluation of mercury and several other air toxics emissions. The AECDP is jointly funded by the United States Department of Energy's Federal Energy Technology Center (DOE), the Ohio Coal Development Office within the Ohio Department of Development (oCDO), and Babcock& Wilcox-a McDermott company (B&W).

  13. An Affect Control Theory of Technology

    ERIC Educational Resources Information Center

    Shank, Daniel B.

    2010-01-01

    Affect control theory is a theory of interaction that takes into account cultural meanings. Affect control research has previously considered interaction with technology, but there remains a lack of theorizing about inclusion of technology within the theory. This paper lays a foundation for an affect control theory of technology by addressing key…

  14. Toward a Cultural Advancement of Tinto's Theory

    ERIC Educational Resources Information Center

    Guiffrida, Douglas A.

    2006-01-01

    Despite the broad appeal of Tinto's (1993) theory, it is not well supported by empirical research, especially when applied to minority students. While prior critiques of the theory indicate the need to modify Tinto's concept of "breaking away" when applying the theory to diverse students, research suggests a need for additional refinements. In…

  15. Advancing Empirical Scholarship to Further Develop Evaluation Theory and Practice

    ERIC Educational Resources Information Center

    Christie, Christina A.

    2011-01-01

    Good theory development is grounded in empirical inquiry. In the context of educational evaluation, the development of empirically grounded theory has important benefits for the field and the practitioner. In particular, a shift to empirically derived theory will assist in advancing more systematic and contextually relevant evaluation practice, as…

  16. Human Intelligence: An Introduction to Advances in Theory and Research.

    ERIC Educational Resources Information Center

    Lohman, David F.

    1989-01-01

    Recent advances in three research traditions are summarized: trait theories of intelligence, information-processing theories of intelligence, and general theories of thinking. Work on fluid and crystallized abilities by J. Horn and R. Snow, mental speed, spatial visualization, cognitive psychology, artificial intelligence, and the construct of…

  17. Recent advances in analytical satellite theory

    NASA Technical Reports Server (NTRS)

    Gaposchkin, E. M.

    1978-01-01

    Recent work on analytical satellite perturbation theory has involved the completion of a revision to 4th order for zonal harmonics, the addition of a treatment for ocean tides, an extension of the treatment for the noninertial reference system, and the completion of a theory for direct solar-radiation pressure and earth-albedo pressure. Combined with a theory for tesseral-harmonics, lunisolar, and body-tide perturbations, these formulations provide a comprehensive orbit-computation program. Detailed comparisons with numerical integration and observations are presented to assess the accuracy of each theoretical development.

  18. Preface: Special Topic on Advances in Density Functional Theory

    SciTech Connect

    Yang, Weitao

    2014-05-14

    This Special Topic Issue on the Advances in Density Functional Theory, published as a celebration of the fifty years of density functional theory, contains a retrospective article, a perspective article, and a collection of original research articles that showcase recent theoretical advances in the field. It provides a timely discussion reflecting a cross section of our understanding, and the theoretical and computational developments, which have significant implications in broad areas of sciences and engineering.

  19. Preface: Special topic on advances in density functional theory.

    PubMed

    Yang, Weitao

    2014-05-14

    This Special Topic Issue on the Advances in Density Functional Theory, published as a celebration of the fifty years of density functional theory, contains a retrospective article, a perspective article, and a collection of original research articles that showcase recent theoretical advances in the field. It provides a timely discussion reflecting a cross section of our understanding, and the theoretical and computational developments, which have significant implications in broad areas of sciences and engineering. PMID:24832306

  20. Advancements to the theory of free solution electrophoresis of polyelectrolytes

    NASA Astrophysics Data System (ADS)

    McCormick, Laurette

    Capillary electrophoresis (CE) is the workhorse of countless analytical laboratories and is used routinely in various industries including pharmaceutical, forensic and clinical applications. Basically, CE is a method for separating charged molecular species in a buffer-filled capillary by the application of an electric field; the analytes move from one end of the capillary to the detector at the other end at speeds determined by their charge, size and shape. Generally, in free solution CE uniformly charged polyelectrolytes (such as DNA) are free-draining, meaning that their speed is independent of their size. Hence, until recently, a gel or other sieving medium has been necessary for the separation of polyelectrolytes; however, modifying uniformly charged polymers on the molecular level, via conjugation to uncharged polymers, allows for separation in free solution CE. In this thesis, advancements to the theory of free solution electrophoresis of polyelectrolytes, in particular, to the theories for two new free solution electrophoresis methods relying on conjugation, are presented. The first method, called End Labelled Free Solution Electrophoresis (ELFSE), can be used to sequence DNA, a negatively charged polymer in solution. Two different means of improving the resolution of ELFSE are predicted, one based on the molecular end effect, the other based on using a controlled electro-osmotic flow. In addition, a theory for the segregation of the DNA and label coils in ELFSE is presented. The second method is called Free Solution Conjugate Electrophoresis (FSCE); it allows for characterization of a sample of neutral polymers differing in length. The relevant theory, developed herein, elucidates how to accurately determine the molar mass distribution of the sample through FSCE measurements. In addition, supporting theories are developed that clarify the correct equation for the diffusion coefficient of molecules undergoing free solution electrophoresis, as well as

  1. Do Advance Organizers Facilitate Learning? A Review of Subsumption Theory.

    ERIC Educational Resources Information Center

    McEneany, John E.

    1990-01-01

    A review of four studies conducted by Ausubel raises serious doubts about the efficacy of advance organizers under a variety of circumstances. In addition, this review questions the adequacy of definitions for two central notions of subsumption theory (discriminability and advance organizer). (IAH)

  2. Integrating Practice and Theory for Advancement

    ERIC Educational Resources Information Center

    Bakewell, Thomas

    2005-01-01

    This is the first installment of a multipart practitioners' guide focused on strategic planning, organizational development, and legal issues. It features practical advice and powerful insights for implementing advancement programs that are organized, productive, and legal--and that generate top results. The author, an organizational development…

  3. Sexual Objectification of Women: Advances to Theory and Research

    ERIC Educational Resources Information Center

    Szymanski, Dawn M.; Moffitt, Lauren B.; Carr, Erika R.

    2011-01-01

    Objectification theory provides an important framework for understanding, researching, and intervening to improve women's lives in a sociocultural context that sexually objectifies the female body and equates a woman's worth with her body's appearance and sexual functions. The purpose of this Major Contribution is to advance theory, research,…

  4. Electroweak Theory: Proceedings of the Advanced School on Electroweak Theory

    NASA Astrophysics Data System (ADS)

    Espriu, D.; Pich, A.

    1998-04-01

    The Table of Contents for the full book PDF is as follows: * Foreword * Quark Mixing and CP Violation * Heavy Quark Effective Theory * Introduction to Low-Energy Supersymmetry * An Introduction to Dynamical Electroweak Symmetry Breaking * Hadron Colliders, the Top Quark, and the Higgs Sector * Physics Potential of LEP2 and NLC * List of Participants

  5. Recent advances in heavy quark theory

    SciTech Connect

    Wise, M.

    1997-01-01

    Some recent developments in heavy quark theory are reviewed. Particular emphasis is given to inclusive weak decays of hadrons containing a b quark. The isospin violating hadronic decay D{sub s}* {yields} D{sub s}{sup pi}{sup 0} is also discussed.

  6. Solidification process control for advanced superalloys

    NASA Technical Reports Server (NTRS)

    Gray, H. R.; Dreshfield, R. L.

    1982-01-01

    The importance of understanding and controlling the basic solidification process in high temperature alloy technology as applied to gas turbine engine production is discussed. Resultant tailoring of the superalloy macro- and microstructure offers significant potential for continued advances in superalloy use temperatures in turbine engines. Atomized superalloy powders, rapidly solidified superalloys, microstructural control, and advanced superalloys are discussed.

  7. Advanced control technology and its potential for future transport aircraft

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The topics covered include fly by wire, digital control, control configured vehicles, applications to advanced flight vehicles, advanced propulsion control systems, and active control technology for transport aircraft.

  8. Recent advances in helix-coil theory.

    PubMed

    Doig, Andrew J

    2002-12-10

    Peptide helices in solution form a complex mixture of all helix, all coil or, most frequently, central helices with frayed coil ends. In order to interpret experiments on helical peptides and make theoretical predictions on helices, it is therefore essential to use a helix-coil theory that takes account of this equilibrium. The original Zimm-Bragg and Lifson-Roig helix-coil theories have been greatly extended in the last 10 years to include additional interactions. These include preferences for the N-cap, N1, N2, N3 and C-cap positions, capping motifs, helix dipoles, side chain interactions and 3(10)-helix formation. These have been applied to determine energies for these preferences from experimental data and to predict the helix contents of peptides. This review discusses these newly recognised structural features of helices and how they have been included in helix-coil models. PMID:12488008

  9. Propulsion control and control theory: A new research focus

    NASA Technical Reports Server (NTRS)

    Zeller, J. R.

    1980-01-01

    Technological developments necessary for the implementation of advanced digital control concepts for aircraft propulsion are identified and discussed. Developments associated with the replacement analog controllers with digital control systems, sensors and actuators, and control modes and software are reported.

  10. Recent Advances in Plasma Edge Physics Theory

    NASA Astrophysics Data System (ADS)

    Stacey, W. M.

    2015-11-01

    This presentation summarizes recent theory developments for interpreting plasma edge physics experiments in DIII-D. i) Radial and poloidal moment balance require that the radial particle flux be of a pinch-diffusive nature with the pinch representing the electromagnetic forces and external momentum input. Ion radial particle fluxes in experiment are found to be a smaller difference between large outward diffusion fluxes and inward pinch fluxes. When the pinch-diffusion relation is used in the continuity equation a new diffusion theory that preserves momentum balance is obtained. ii) The majority of thermalized ions and their energy cross the LCFS on ion loss orbits and are deposited in the SOL near the outboard midplane. The lost ions are predominantly ctr-current, producing a co-current intrinsic rotation of the remaining ions in the edge plasma. iii) While the contribution of the leading order parallel viscosity to toroidal momentum damping vanishes identically in axisymmetric plasmas, non-axisymmetric radial B-fields in the edge plasma enable parallel viscosity to enhance the damping of toroidal rotation. Work supported by the US DOE under DE-FG02-00ER54538, DE-FC02-04ER54698.

  11. Issues in advanced automation for manipulator control

    NASA Technical Reports Server (NTRS)

    Bejczy, A. K.

    1976-01-01

    This paper provides a brief description and analysis of the main issues in advanced autonomous control of manipulators as seen from a system point of view. The nature of manipulation is analyzed at some depth. A general multilevel structure is outlined for manipulator control organization which includes the human operator at the top level of the control structure. Different approaches to the development of advanced automation of mechanical arms are summarized. Recent work in the JPL teleoperator project is described, including control system, force/torque sensor, and control software development. Some results from control experiments are summarized.

  12. Performance of Children and Adolescents with Asperger Syndrome or High-Functioning Autism on Advanced Theory of Mind Tasks

    ERIC Educational Resources Information Center

    Kaland, Nils; Callesen, Kirsten; Moller-Nielsen, Annette; Mortensen, Erik Lykke; Smith, Lars

    2008-01-01

    Although a number of advanced theory of mind tasks have been developed, there is a dearth of information on whether performances on different tasks are associated. The present study examined the performance of 21 children and adolescents with diagnoses of Asperger syndrome (AS) and 20 typically developing controls on three advanced theory of mind…

  13. Advances in the theory of box integrals

    SciTech Connect

    Bailey, David H.; Borwein, J.M.; Crandall, R.E.

    2009-06-25

    Box integrals - expectations <|{rvec r}|{sup s}> or <|{rvec r}-{rvec q}|{sup s}> over the unit n-cube (or n-box) - have over three decades been occasionally given closed forms for isolated n,s. By employing experimental mathematics together with a new, global analytic strategy, we prove that for n {le} 4 dimensions the box integrals are for any integer s hypergeometrically closed in a sense we clarify herein. For n = 5 dimensions, we show that a single unresolved integral we call K{sub 5} stands in the way of such hyperclosure proofs. We supply a compendium of exemplary closed forms that naturally arise algorithmically from this theory.

  14. Theory and applications survey of decentralized control methods

    NASA Technical Reports Server (NTRS)

    Athans, M.

    1975-01-01

    A nonmathematical overview is presented of trends in the general area of decentralized control strategies which are suitable for hierarchical systems. Advances in decentralized system theory are closely related to advances in the so-called stochastic control problem with nonclassical information pattern. The basic assumptions and mathematical tools pertaining to the classical stochastic control problem are outlined. Particular attention is devoted to pitfalls in the mathematical problem formulation for decentralized control. Major conclusions are that any purely deterministic approach to multilevel hierarchical dynamic systems is unlikely to lead to realistic theories or designs, that the flow of measurements and decisions in a decentralized system should not be instantaneous and error-free, and that delays in information exchange in a decentralized system lead to reasonable approaches to decentralized control. A mathematically precise notion of aggregating information is not yet available.

  15. Recent advances in electronic structure theory

    NASA Astrophysics Data System (ADS)

    Piecuch, Piotr; Kowalski, Karol; Pimienta, Ian S. O.; McGuire, Michael J.

    The recently developed new approach to the many-electron correlation problem in atoms and molecules, termed the method of moments of coupled-cluster (CC) equations (MMCC), is reviewed. The ground-state MMCC formalism and its extension to excited electronic states via the equation-of-motion coupled-cluster (EOMCC) approach are discussed. The main principle of all MMCC methods is that of the non-iterative energy corrections which, when added to the ground- and excited-state energies obtained in the standard CC calculations, such as CCSD or EOMCCSD, recover the exact, full configuration interaction (CI) energies. Three types of the MMCC approximations are reviewed in detail: (i) the CI-corrected MMCC methods, which can be applied to ground and excited states; (ii) the renormalized and completely renormalized CC methods for ground states; and (iii) the quasi-variational MMCC approaches for the ground-state problem, including the quadratic MMCC models. It is demonstrated that the MMCC formalism provides a new theoretical framework for designing 'black-box' CC approaches that lead to an excellent description of entire potential energy surfaces of ground- and excited-state molecular systems with an ease of use of the standard single-reference methods. The completely renormalized (CR) CCSD(T) and CCSD(TQ) methods and their quadratic and excited-state MMCC analogues remove the failing of the standard CCSD, CCSD(T), EOMCCSD and similar methods at larger internuclear separations and for states that normally require a genuine multireference description. All theoretical ideas are illustrated by numerical examples involving bond breaking, excited vibrational states, reactive potential energy surfaces and difficult cases of excited electronic states. The description of the existing and well-established variants of the MMCC theory, such as CR-CCSD(T), is augmented by the discussion of future prospects and potentially useful recent developments, including the extension of the black

  16. Advanced thermal control for spacecraft applications

    NASA Astrophysics Data System (ADS)

    Hardesty, Robert; Parker, Kelsey

    2015-09-01

    In optical systems just like any other space borne system, thermal control plays an important role. In fact, most advanced designs are plagued with volume constraints that further complicate the thermal control challenges for even the most experienced systems engineers. Peregrine will present advances in satellite thermal control based upon passive heat transfer technologies to dissipate large thermal loads. This will address the use of 700 W/m K and higher conducting products that are five times better than aluminum on a specific basis providing enabling thermal control while maintaining structural support.

  17. Advanced Thermal HPT Clearance Control

    NASA Technical Reports Server (NTRS)

    WojciechVoytek, Sak

    2006-01-01

    OBJECTIVE: Develop a fast acting HPT Active Clearance Control System to improve engine efficiency and reduce emissions CHALLENGE: Reduction of HPT blade clearance throughout engine operation System complexity, reliability and cost must remain comparable or surpass today s engines Reduced clearance may increase possibility of rubs

  18. Advanced Emission Control Development Program.

    SciTech Connect

    Evans, A.P.

    1997-12-31

    Babcock & Wilcox (B&W) is conducting a five-year project aimed at the development of practical, cost-effective strategies for reducing the emissions of hazardous air pollutants (commonly called air toxics) from coal-fired electric utility plants. The need for air toxic emissions controls may arise as the U. S. Environmental Protection Agency proceeds with implementation of Title III of the Clean Air Act Amendment (CAAA) of 1990. Data generated during the program will provide utilities with the technical and economic information necessary to reliably evaluate various air toxics emissions compliance options such as fuel switching, coal cleaning, and flue gas treatment. The development work is being carried out using B&W`s new Clean Environment Development Facility (CEDF) wherein air toxics emissions control strategies can be developed under controlled conditions, and with proven predictability to commercial systems. Tests conducted in the CEDF provide high quality, repeatable, comparable data over a wide range of coal properties, operating conditions, and emissions control systems. Development work to date has concentrated on the capture of mercury, other trace metals, fine particulate, and the inorganic species hydrogen chloride and hydrogen fluoride.

  19. Advanced Emissions Control Development Program

    SciTech Connect

    Evans, A P

    1998-12-03

    Babcock & Wilcox (B&W) is conducting a five-year project aimed at the development of practical, cost-effective strategies for reducing the emissions of hazardous air pollutants (commonly called air toxics) from coal-fired electric utility plants. The need for air toxic emissions controls may arise as the U. S. Environmental Protection Agency proceeds with implementation of Title III of the Clean Air Act Amendment (CAAA) of 1990. Data generated during the program will provide utilities with the technical and economic information necessary to reliably evaluate various air toxics emissions compliance options such as fuel switching, coal cleaning, and flue gas treatment. The development work is being carried out using B&W's new Clean Environment Development Facility (CEDF) wherein air toxics emissions control strategies can be developed under controlled conditions, and with proven predictability to commercial systems. Tests conducted in the CEDF provide high quality, repeatable, comparable data over a wide range of coal properties, operating conditions, and emissions control systems. Development work to date has concentrated on the capture of mercury, other trace metals, fine particulate, and the inorganic species hydrogen chloride and hydrogen fluoride.

  20. Advanced Emissions Control Development Program

    SciTech Connect

    M. J. Holmes

    1998-12-03

    McDermott Technology, Inc. (MTI) is conducting a five-year project aimed at the development of practical, cost-effective strategies for reducing the emissions of hazardous air pollutants (commonly called air toxics) from coal-fired electric utility plants. The need for air toxic emissions controls may arise as the U. S. Environmental Protection Agency proceeds with implementation of Title III of the Clean Air Act Amendment (CAAA) of 1990. Data generated during the program will provide utilities with the technical and economic information necessary to reliably evaluate various air toxics emissions compliance options such as fuel switching, coal cleaning, and flue gas treatment. The development work is being carried out using the Clean Environment Development Facility (CEDF) wherein air toxics emissions control strategies can be developed under controlled conditions, and with proven predictability to commercial systems. Tests conducted in the CEDF provide high quality, repeatable, comparable data over a wide range of coal properties, operating conditions, and emissions control systems. Development work to date has concentrated on the capture of mercury, other trace metals, fine particulate, and hydrogen chloride and hydrogen fluoride.

  1. Advanced Emissions Control Development Program

    SciTech Connect

    A. P. Evans

    1998-12-03

    McDermott Technology, Inc. (MTI) is conducting a five-year project aimed at the development of practical, cost-effective strategies for reducing the emissions of hazardous air pollutants (commonly called air toxics) from coal-fired electric utility plants. The need for air toxic emissions controls may arise as the U. S. Environmental Protection Agency proceeds with implementation of Title III of the Clean Air Act Amendment (CAAA) of 1990. Data generated during the program will provide utilities with the technical and economic information necessary to reliably evaluate various air toxics emissions compliance options such as fuel switching, coal cleaning, and flue gas treatment. The development work is being carried out using the Clean Environment Development Facility (CEDF) wherein air toxics emissions control strategies can be developed under controlled conditions, and with proven predictability to commercial systems. Tests conducted in the CEDF provide high quality, repeatable, comparable data over a wide range of coal properties, operating conditions, and emissions control systems. Development work to date has concentrated on the capture of mercury, other trace metals, fine particulate, and the inorganic species, hydrogen chloride and hydrogen fluoride.

  2. Teaching Melodic Dictation in Advanced Placement Music Theory

    ERIC Educational Resources Information Center

    Paney, Andrew S.; Buonviri, Nathan O.

    2014-01-01

    In this study approaches to teaching melodic dictation skills used by Advanced Placement (AP) Music Theory teachers were examined. Twelve high school teachers from four states were interviewed. Four themes emerged from the interview transcripts: cognitive frameworks, processing strategies, rhythm, and course design. Participants generally…

  3. Learning to Control Advanced Life Support Systems

    NASA Technical Reports Server (NTRS)

    Subramanian, Devika

    2004-01-01

    Advanced life support systems have many interacting processes and limited resources. Controlling and optimizing advanced life support systems presents unique challenges. In particular, advanced life support systems are nonlinear coupled dynamical systems and it is difficult for humans to take all interactions into account to design an effective control strategy. In this project. we developed several reinforcement learning controllers that actively explore the space of possible control strategies, guided by rewards from a user specified long term objective function. We evaluated these controllers using a discrete event simulation of an advanced life support system. This simulation, called BioSim, designed by Nasa scientists David Kortenkamp and Scott Bell has multiple, interacting life support modules including crew, food production, air revitalization, water recovery, solid waste incineration and power. They are implemented in a consumer/producer relationship in which certain modules produce resources that are consumed by other modules. Stores hold resources between modules. Control of this simulation is via adjusting flows of resources between modules and into/out of stores. We developed adaptive algorithms that control the flow of resources in BioSim. Our learning algorithms discovered several ingenious strategies for maximizing mission length by controlling the air and water recycling systems as well as crop planting schedules. By exploiting non-linearities in the overall system dynamics, the learned controllers easily out- performed controllers written by human experts. In sum, we accomplished three goals. We (1) developed foundations for learning models of coupled dynamical systems by active exploration of the state space, (2) developed and tested algorithms that learn to efficiently control air and water recycling processes as well as crop scheduling in Biosim, and (3) developed an understanding of the role machine learning in designing control systems for

  4. Advanced automation in space shuttle mission control

    NASA Technical Reports Server (NTRS)

    Heindel, Troy A.; Rasmussen, Arthur N.; Mcfarland, Robert Z.

    1991-01-01

    The Real Time Data System (RTDS) Project was undertaken in 1987 to introduce new concepts and technologies for advanced automation into the Mission Control Center environment at NASA's Johnson Space Center. The project's emphasis is on producing advanced near-operational prototype systems that are developed using a rapid, interactive method and are used by flight controllers during actual Shuttle missions. In most cases the prototype applications have been of such quality and utility that they have been converted to production status. A key ingredient has been an integrated team of software engineers and flight controllers working together to quickly evolve the demonstration systems.

  5. JPL Advanced Thermal Control Technology Roadmap - 2012

    NASA Technical Reports Server (NTRS)

    Birur, Gaj; Rodriguez, Jose I.

    2012-01-01

    NASA's new emphasis on human exploration program for missions beyond LEO requires development of innovative and revolutionary technologies. Thermal control requirements of future NASA science instruments and missions are very challenging and require advanced thermal control technologies. Limited resources requires organizations to cooperate and collaborate; government, industry, universities all need to work together for the successful development of these technologies.

  6. Applications of robust control theory - Educational implications

    NASA Technical Reports Server (NTRS)

    Dorato, P.; Yedavalli, R. K.

    1992-01-01

    A survey is made of applications of robust control theory to problems of flight control, control of flexible space structures, and engine control which have appeared in recent conferences and journals. An analysis is made of which theoretical techniques are most commonly used and what implications this has for graduate and undergraduate education in aerospace engineering.

  7. Experimental development of power reactor advanced controllers

    SciTech Connect

    Edwards, R.M.; Weng, C.K.; Lindsay, R.W.

    1992-06-01

    A systematic approach for developing and verifying advanced controllers with potential application to commercial nuclear power plants is suggested. The central idea is to experimentally demonstrate an advanced control concept first on an ultra safe research reactor followed by demonstration on a passively safe experimental power reactor and then finally adopt the technique for improving safety, performance, reliability and operability at commercial facilities. Prior to completing an experimental sequence, the benefits and utility of candidate advanced controllers should be established through theoretical development and simulation testing. The applicability of a robust optimal observer-based state feedback controller design process for improving reactor temperature response for a TRIGA research reactor, Liquid Metal-cooled Reactor (LMR), and a commercial Pressurized Water Reactor (PWR) is presented to illustrate the potential of the proposed experimental development concept.

  8. Experimental development of power reactor advanced controllers

    SciTech Connect

    Edwards, R.M. . Dept. of Nuclear Engineering); Weng, C.K. . Dept. of Mechanical Engineering); Lindsay, R.W. )

    1992-01-01

    A systematic approach for developing and verifying advanced controllers with potential application to commercial nuclear power plants is suggested. The central idea is to experimentally demonstrate an advanced control concept first on an ultra safe research reactor followed by demonstration on a passively safe experimental power reactor and then finally adopt the technique for improving safety, performance, reliability and operability at commercial facilities. Prior to completing an experimental sequence, the benefits and utility of candidate advanced controllers should be established through theoretical development and simulation testing. The applicability of a robust optimal observer-based state feedback controller design process for improving reactor temperature response for a TRIGA research reactor, Liquid Metal-cooled Reactor (LMR), and a commercial Pressurized Water Reactor (PWR) is presented to illustrate the potential of the proposed experimental development concept.

  9. Control theory for random systems

    NASA Technical Reports Server (NTRS)

    Bryson, A. E., Jr.

    1972-01-01

    A survey is presented of the current knowledge available for designing and predicting the effectiveness of controllers for dynamic systems which can be modeled by ordinary differential equations. A short discussion of feedback control is followed by a description of deterministic controller design and the concept of system state. The need for more realistic disturbance models led to the use of stochastic process concepts, in particular the Gauss-Markov process. A compensator controlled system, with random forcing functions, random errors in the measurements, and random initial conditions, is treated as constituting a Gauss-Markov random process; hence the mean-square behavior of the controlled system is readily predicted. As an example, a compensator is designed for a helicopter to maintain it in hover in a gusty wind over a point on the ground.

  10. Operational efficiency subpanel advanced mission control

    NASA Technical Reports Server (NTRS)

    Friedland, Peter

    1990-01-01

    Herein, the term mission control will be taken quite broadly to include both ground and space based operations as well as the information infrastructure necessary to support such operations. Three major technology areas related to advanced mission control are examined: (1) Intelligent Assistance for Ground-Based Mission Controllers and Space-Based Crews; (2) Autonomous Onboard Monitoring, Control and Fault Detection Isolation and Reconfiguration; and (3) Dynamic Corporate Memory Acquired, Maintained, and Utilized During the Entire Vehicle Life Cycle. The current state of the art space operations are surveyed both within NASA and externally for each of the three technology areas and major objectives are discussed from a user point of view for technology development. Ongoing NASA and other governmental programs are described. An analysis of major research issues and current holes in the program are provided. Several recommendations are presented for enhancing the technology development and insertion process to create advanced mission control environments.

  11. Advanced mean-field theory of the restricted Boltzmann machine

    NASA Astrophysics Data System (ADS)

    Huang, Haiping; Toyoizumi, Taro

    2015-05-01

    Learning in restricted Boltzmann machine is typically hard due to the computation of gradients of log-likelihood function. To describe the network state statistics of the restricted Boltzmann machine, we develop an advanced mean-field theory based on the Bethe approximation. Our theory provides an efficient message-passing-based method that evaluates not only the partition function (free energy) but also its gradients without requiring statistical sampling. The results are compared with those obtained by the computationally expensive sampling-based method.

  12. Control theory meets synthetic biology.

    PubMed

    Del Vecchio, Domitilla; Dy, Aaron J; Qian, Yili

    2016-07-01

    The past several years have witnessed an increased presence of control theoretic concepts in synthetic biology. This review presents an organized summary of how these control design concepts have been applied to tackle a variety of problems faced when building synthetic biomolecular circuits in living cells. In particular, we describe success stories that demonstrate how simple or more elaborate control design methods can be used to make the behaviour of synthetic genetic circuits within a single cell or across a cell population more reliable, predictable and robust to perturbations. The description especially highlights technical challenges that uniquely arise from the need to implement control designs within a new hardware setting, along with implemented or proposed solutions. Some engineering solutions employing complex feedback control schemes are also described, which, however, still require a deeper theoretical analysis of stability, performance and robustness properties. Overall, this paper should help synthetic biologists become familiar with feedback control concepts as they can be used in their application area. At the same time, it should provide some domain knowledge to control theorists who wish to enter the rising and exciting field of synthetic biology. PMID:27440256

  13. Control theory meets synthetic biology

    PubMed Central

    2016-01-01

    The past several years have witnessed an increased presence of control theoretic concepts in synthetic biology. This review presents an organized summary of how these control design concepts have been applied to tackle a variety of problems faced when building synthetic biomolecular circuits in living cells. In particular, we describe success stories that demonstrate how simple or more elaborate control design methods can be used to make the behaviour of synthetic genetic circuits within a single cell or across a cell population more reliable, predictable and robust to perturbations. The description especially highlights technical challenges that uniquely arise from the need to implement control designs within a new hardware setting, along with implemented or proposed solutions. Some engineering solutions employing complex feedback control schemes are also described, which, however, still require a deeper theoretical analysis of stability, performance and robustness properties. Overall, this paper should help synthetic biologists become familiar with feedback control concepts as they can be used in their application area. At the same time, it should provide some domain knowledge to control theorists who wish to enter the rising and exciting field of synthetic biology. PMID:27440256

  14. Geometrically constrained observability. [control theory

    NASA Technical Reports Server (NTRS)

    Brammer, R. F.

    1974-01-01

    This paper deals with observed processes in situations in which observations are available only when the state vector lies in certain regions. For linear autonomous observed processes, necessary and sufficient conditions are obtained for half-space observation regions. These results are shown to contain a theorem dual to a controllability result proved by the author for a linear autonomous control system whose control restraint set does not contain the origin as an interior point. Observability results relating to continuous observation systems and sampled data systems are presented, and an example of observing the state of an electrical network is given.

  15. Advanced control architecture for autonomous vehicles

    NASA Astrophysics Data System (ADS)

    Maurer, Markus; Dickmanns, Ernst D.

    1997-06-01

    An advanced control architecture for autonomous vehicles is presented. The hierarchical architecture consists of four levels: a vehicle level, a control level, a rule-based level and a knowledge-based level. A special focus is on forms of internal representation, which have to be chosen adequately for each level. The control scheme is applied to VaMP, a Mercedes passenger car which autonomously performs missions on German freeways. VaMP perceives the environment with its sense of vision and conventional sensors. It controls its actuators for locomotion and attention focusing. Modules for perception, cognition and action are discussed.

  16. Advanced instrumentation concepts for environmental control subsystems

    NASA Technical Reports Server (NTRS)

    Yang, P. Y.; Schubert, F. H.; Gyorki, J. R.; Wynveen, R. A.

    1978-01-01

    Design, evaluation and demonstration of advanced instrumentation concepts for improving performance of manned spacecraft environmental control and life support systems were successfully completed. Concepts to aid maintenance following fault detection and isolation were defined. A computer-guided fault correction instruction program was developed and demonstrated in a packaged unit which also contains the operator/system interface.

  17. Yield advances in peanut - weed control effects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Improvements in weed management are a contributing factor to advancements in peanut yield. Widespread use of vacuum planters and increased acceptance of narrow row patterns enhance weed control by lessening bareground caused by skips and promoting quick canopy closure. Cultivation was traditionall...

  18. Microprocessor controlled advanced battery management systems

    NASA Technical Reports Server (NTRS)

    Payne, W. T.

    1978-01-01

    The advanced battery management system described uses the capabilities of an on-board microprocessor to: (1) monitor the state of the battery on a cell by cell basis; (2) compute the state of charge of each cell; (3) protect each cell from reversal; (4) prevent overcharge on each individual cell; and (5) control dual rate reconditioning to zero volts per cell.

  19. Advanced technologies for Mission Control Centers

    NASA Technical Reports Server (NTRS)

    Dalton, John T.; Hughes, Peter M.

    1991-01-01

    Advance technologies for Mission Control Centers are presented in the form of the viewgraphs. The following subject areas are covered: technology needs; current technology efforts at GSFC (human-machine interface development, object oriented software development, expert systems, knowledge-based software engineering environments, and high performance VLSI telemetry systems); and test beds.

  20. MERCURY CONTROL WITH ADVANCED HYBRID PARTICULATE COLLECTOR

    SciTech Connect

    Ye Zhuang; Stanley J. Miller

    2005-05-01

    This project was awarded under U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) Program Solicitation DE-PS26-00NT40769 and specifically addressed Technical Topical Area 4-Testing Novel and Less Mature Control Technologies on Actual Flue Gas at the Pilot Scale. The project team included the Energy & Environmental Research Center (EERC) as the main contractor; W.L. Gore & Associates, Inc., as a technical and financial partner; and the Big Stone Power Plant operated by Otter Tail Power Company, host for the field-testing portion of the research. Since 1995, DOE has supported development of a new concept in particulate control called the advanced hybrid particulate collector (AHPC). The AHPC has been licensed to W.L. Gore & Associates, Inc., and has been marketed as the Advanced Hybrid{trademark} filter by Gore. The Advanced Hybrid{trademark} filter combines the best features of electrostatic precipitators (ESPs) and baghouses in a unique configuration, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The Advanced Hybrid{trademark} filter provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and it solves the problem of reentrainment and re-collection of dust in conventional baghouses. The Advanced Hybrid{trademark} filter also appears to have unique advantages for mercury control over baghouses or ESPs as an excellent gas--solid contactor. The objective of the project was to demonstrate 90% total mercury control in the Advanced Hybrid{trademark} filter at a lower cost than current mercury control estimates. The approach included bench-scale batch tests, larger-scale pilot testing with real flue gas on a coal-fired combustion system, and field demonstration at the 2.5-MW (9000-acfm) scale at a utility power plant to prove scale-up and demonstrate longer-term mercury control

  1. Advanced Active Thermal Control Systems Architecture Study

    NASA Technical Reports Server (NTRS)

    Hanford, Anthony J.; Ewert, Michael K.

    1996-01-01

    The Johnson Space Center (JSC) initiated a dynamic study to determine possible improvements available through advanced technologies (not used on previous or current human vehicles), identify promising development initiatives for advanced active thermal control systems (ATCS's), and help prioritize funding and personnel distribution among many research projects by providing a common basis to compare several diverse technologies. Some technologies included were two-phase thermal control systems, light-weight radiators, phase-change thermal storage, rotary fluid coupler, and heat pumps. JSC designed the study to estimate potential benefits from these various proposed and under-development thermal control technologies for five possible human missions early in the next century. The study compared all the technologies to a baseline mission using mass as a basis. Each baseline mission assumed an internal thermal control system; an external thermal control system; and aluminum, flow-through radiators. Solar vapor compression heat pumps and light-weight radiators showed the greatest promise as general advanced thermal technologies which can be applied across a range of missions. This initial study identified several other promising ATCS technologies which offer mass savings and other savings compared to traditional thermal control systems. Because the study format compares various architectures with a commonly defined baseline, it is versatile and expandable, and is expected to be updated as needed.

  2. An information theory account of cognitive control

    PubMed Central

    Fan, Jin

    2014-01-01

    Our ability to efficiently process information and generate appropriate responses depends on the processes collectively called cognitive control. Despite a considerable focus in the literature on the cognitive control of information processing, neural mechanisms underlying control are still unclear, and have not been characterized by considering the quantity of information to be processed. A novel and comprehensive account of cognitive control is proposed using concepts from information theory, which is concerned with communication system analysis and the quantification of information. This account treats the brain as an information-processing entity where cognitive control and its underlying brain networks play a pivotal role in dealing with conditions of uncertainty. This hypothesis and theory article justifies the validity and properties of such an account and relates experimental findings to the frontoparietal network under the framework of information theory. PMID:25228875

  3. Optimal control and Galois theory

    SciTech Connect

    Zelikin, M I; Kiselev, D D; Lokutsievskiy, L V

    2013-11-30

    An important role is played in the solution of a class of optimal control problems by a certain special polynomial of degree 2(n−1) with integer coefficients. The linear independence of a family of k roots of this polynomial over the field Q implies the existence of a solution of the original problem with optimal control in the form of an irrational winding of a k-dimensional Clifford torus, which is passed in finite time. In the paper, we prove that for n≤15 one can take an arbitrary positive integer not exceeding [n/2] for k. The apparatus developed in the paper is applied to the systems of Chebyshev-Hermite polynomials and generalized Chebyshev-Laguerre polynomials. It is proved that for such polynomials of degree 2m every subsystem of [(m+1)/2] roots with pairwise distinct squares is linearly independent over the field Q. Bibliography: 11 titles.

  4. Rotorcraft flying qualities improvement using advanced control

    NASA Technical Reports Server (NTRS)

    Walker, D.; Postlethwaite, I.; Howitt, J.; Foster, N.

    1993-01-01

    We report on recent experience gained when a multivariable helicopter flight control law was tested on the Large Motion Simulator (LMS) at DRA Bedford. This was part of a study into the application of multivariable control theory to the design of full-authority flight control systems for high-performance helicopters. In this paper, we present some of the results that were obtained during the piloted simulation trial and from subsequent off-line simulation and analysis. The performance provided by the control law led to level 1 handling quality ratings for almost all of the mission task elements assessed, both during the real-time and off-line analysis.

  5. An advanced control system for a next generation transport aircraft

    NASA Technical Reports Server (NTRS)

    Rising, J. J.; Davis, W. J; Grantham, W. D.

    1983-01-01

    The use of modern control theory to develop a high-authority stability and control system for the next generation transport aircraft is described with examples taken from work performed on an advanced pitch active control system (PACS). The PACS was configured to have short-period and phugoid modes frequency and damping characteristics within the shaded S-plane areas, column force gradients with set bounds and with constant slope, and a blended normal-acceleration/pitch rate time history response to a step command. Details of the control law, feedback loop, and modal control syntheses are explored, as are compensation for the feedback gain, the deletion of the velocity signal, and the feed-forward compensation. Scheduling of the primary and secondary gains are discussed, together with control law mechanization, flying qualities analyses, and application on the L-1011 aircraft.

  6. Architectures & requirements for advanced weapon controllers.

    SciTech Connect

    McMurtrey, Brian J.; Klarer, Paul Richard; Bryan, Jon R.

    2004-02-01

    This report describes work done in FY2003 under Advanced and Exploratory Studies funding for Advanced Weapons Controllers. The contemporary requirements and envisioned missions for nuclear weapons are changing from the class of missions originally envisioned during development of the current stockpile. Technology available today in electronics, computing, and software provides capabilities not practical or even possible 20 years ago. This exploratory work looks at how Weapon Electrical Systems can be improved to accommodate new missions and new technologies while maintaining or improving existing standards in nuclear safety and reliability.

  7. Introduction to Advanced Engine Control Concepts

    NASA Technical Reports Server (NTRS)

    Sanjay, Garg

    2007-01-01

    With the increased emphasis on aircraft safety, enhanced performance and affordability, and the need to reduce the environmental impact of aircraft, there are many new challenges being faced by the designers of aircraft propulsion systems. The Controls and Dynamics Branch at NASA (National Aeronautics and Space Administration) Glenn Research Center (GRC) in Cleveland, Ohio, is leading and participating in various projects in partnership with other organizations within GRC and across NASA, the U.S. aerospace industry, and academia to develop advanced controls and health management technologies that will help meet these challenges through the concept of Intelligent Propulsion Systems. The key enabling technologies for an Intelligent Propulsion System are the increased efficiencies of components through active control, advanced diagnostics and prognostics integrated with intelligent engine control to enhance operational reliability and component life, and distributed control with smart sensors and actuators in an adaptive fault tolerant architecture. This presentation describes the current activities of the Controls and Dynamics Branch in the areas of active component control and propulsion system intelligent control, and presents some recent analytical and experimental results in these areas.

  8. Human factors challenges for advanced process control

    SciTech Connect

    Stubler, W.F.; O`Hara, J..M.

    1996-08-01

    New human-system interface technologies provide opportunities for improving operator and plant performance. However, if these technologies are not properly implemented, they may introduce new challenges to performance and safety. This paper reports the results from a survey of human factors considerations that arise in the implementation of advanced human-system interface technologies in process control and other complex systems. General trends were identified for several areas based on a review of technical literature and a combination of interviews and site visits with process control organizations. Human factors considerations are discussed for two of these areas, automation and controls.

  9. Exposure tool control for advanced semiconductor lithography

    NASA Astrophysics Data System (ADS)

    Matsuyama, Tomoyuki

    2015-08-01

    This is a review paper to show how we control exposure tool parameters in order to satisfy patterning performance and productivity requirements for advanced semiconductor lithography. In this paper, we will discuss how we control illumination source shape to satisfy required imaging performance, heat-induced lens aberration during exposure to minimize the aberration impact on imaging, dose and focus control to realize uniform patterning performance across the wafer and patterning position of circuit patterns on different layers. The contents are mainly about current Nikon immersion exposure tools.

  10. Controlling air toxics through advanced coal preparation

    SciTech Connect

    Straszheim, W.E.; Buttermore, W.H.; Pollard, J.L.

    1995-11-01

    This project involves the assessment of advanced coal preparation methods for removing trace elements from coal to reduce the potential for air toxic emissions upon combustion. Scanning electron microscopy-based automated image analysis (SEM-AIA) and advanced washability analyses are being applied with state-of-the-art analytical procedures to predict the removal of elements of concern by advanced column flotation and to confirm the effectiveness of preparation on the quality of quantity of clean coal produced. Specific objectives are to maintain an acceptable recovery of combustible product, while improving the rejection of mineral-associated trace elements. Current work has focused on determining conditions for controlling column flotation system across its operating range and on selection and analysis of samples for determining trace element cleanability.

  11. INTEGRATED PLASMA CONTROL FOR ADVANCED TOKAMAKS

    SciTech Connect

    HUMPHREYS,D.A; FERRON,J.R; JOHNSON,R.D; LEUER,J.A; PENAFLOR,B.G; WALKER,M.L; WELANDER,A.S; KHAYRUTDINOV,R.R; DOKOUKA,V; EDGELL,D.H; FRANSSON,C.M

    2003-10-01

    OAK-B135 Advanced tokamaks (AT) are distinguished from conventional tokamaks by their high degree of shaping, achievement of profiles optimized for high confinement and stability characteristics, and active stabilization of MHD instabilities to attain high values of normalized beta and confinement. These high performance fusion devices thus require accurate regulation of the plasma boundary, internal profiles, pumping, fueling, and heating, as well as simultaneous and well-coordinated MHD control action to stabilize such instabilities as tearing modes and resistive wall modes. Satisfying the simultaneous demands on control accuracy, reliability, and performance for all of these subsystems requires a high degree of integration in both design and operation of the plasma control system in an advanced tokamak. The present work describes the approach, benefits, and progress made in integrated plasma control with application examples drawn from the DIII-D tokamak. The approach includes construction of plasma and system response models, validation of models against operating experiments, design of integrated controllers which operate in concert with one another as well as with supervisory modules, simulation of control action against off-line and actual machine control platforms, and iteration of the design-test loop to optimize performance.

  12. Advanced avionics concepts: Autonomous spacecraft control

    NASA Technical Reports Server (NTRS)

    1990-01-01

    A large increase in space operations activities is expected because of Space Station Freedom (SSF) and long range Lunar base missions and Mars exploration. Space operations will also increase as a result of space commercialization (especially the increase in satellite networks). It is anticipated that the level of satellite servicing operations will grow tenfold from the current level within the next 20 years. This growth can be sustained only if the cost effectiveness of space operations is improved. Cost effectiveness is operational efficiency with proper effectiveness. A concept is presented of advanced avionics, autonomous spacecraft control, that will enable the desired growth, as well as maintain the cost effectiveness (operational efficiency) in satellite servicing operations. The concept of advanced avionics that allows autonomous spacecraft control is described along with a brief description of each component. Some of the benefits of autonomous operations are also described. A technology utilization breakdown is provided in terms of applications.

  13. The Advanced Noise Control Fan Baseline Measurements

    NASA Technical Reports Server (NTRS)

    McAllister, Joseph; Loew, Raymond A.; Lauer, Joel T.; Stuliff, Daniel L.

    2009-01-01

    The NASA Glenn Research Center s (NASA Glenn) Advanced Noise Control Fan (ANCF) was developed in the early 1990s to provide a convenient test bed to measure and understand fan-generated acoustics, duct propagation, and radiation to the farfield. As part of a complete upgrade, current baseline and acoustic measurements were documented. Extensive in-duct, farfield acoustic, and flow field measurements are reported. This is a follow-on paper to documenting the operating description of the ANCF.

  14. Building a functional multiple intelligences theory to advance educational neuroscience.

    PubMed

    Cerruti, Carlo

    2013-01-01

    A key goal of educational neuroscience is to conduct constrained experimental research that is theory-driven and yet also clearly related to educators' complex set of questions and concerns. However, the fields of education, cognitive psychology, and neuroscience use different levels of description to characterize human ability. An important advance in research in educational neuroscience would be the identification of a cognitive and neurocognitive framework at a level of description relatively intuitive to educators. I argue that the theory of multiple intelligences (MI; Gardner, 1983), a conception of the mind that motivated a past generation of teachers, may provide such an opportunity. I criticize MI for doing little to clarify for teachers a core misunderstanding, specifically that MI was only an anatomical map of the mind but not a functional theory that detailed how the mind actually processes information. In an attempt to build a "functional MI" theory, I integrate into MI basic principles of cognitive and neural functioning, namely interregional neural facilitation and inhibition. In so doing I hope to forge a path toward constrained experimental research that bears upon teachers' concerns about teaching and learning. PMID:24391613

  15. Building a functional multiple intelligences theory to advance educational neuroscience

    PubMed Central

    Cerruti, Carlo

    2013-01-01

    A key goal of educational neuroscience is to conduct constrained experimental research that is theory-driven and yet also clearly related to educators’ complex set of questions and concerns. However, the fields of education, cognitive psychology, and neuroscience use different levels of description to characterize human ability. An important advance in research in educational neuroscience would be the identification of a cognitive and neurocognitive framework at a level of description relatively intuitive to educators. I argue that the theory of multiple intelligences (MI; Gardner, 1983), a conception of the mind that motivated a past generation of teachers, may provide such an opportunity. I criticize MI for doing little to clarify for teachers a core misunderstanding, specifically that MI was only an anatomical map of the mind but not a functional theory that detailed how the mind actually processes information. In an attempt to build a “functional MI” theory, I integrate into MI basic principles of cognitive and neural functioning, namely interregional neural facilitation and inhibition. In so doing I hope to forge a path toward constrained experimental research that bears upon teachers’ concerns about teaching and learning. PMID:24391613

  16. Research and development on the application of advanced control technologies to advanced nuclear reactor systems: A US national perspective

    SciTech Connect

    White, J.D.; Monson, L.R.; Carrol, D.G.; Dayal, Y.; Argonne National Lab., IL; General Electric Co., San Jose, CA )

    1989-01-01

    Control system designs for nuclear power plants are becoming more advanced through the use of digital technology and automation. This evolution is taking place because of: (1) the limitations in analog based control system performance and maintenance and availability and (2) the promise of significant improvement in plant operation and availability due to advances in digital and other control technologies. Digital retrofits of control systems in US nuclear plants are occurring now. Designs of control and protection systems for advanced LWRs are based on digital technology. The use of small inexpensive, fast, large-capacity computers in these designs is the first step of an evolutionary process described in this paper. Under the sponsorship of the US Department of Energy (DOE), Oak Ridge National Laboratory, Argonne National Laboratory, GE Nuclear Energy and several universities are performing research and development in the application of advances in control theory, software engineering, advanced computer architectures, artificial intelligence, and man-machine interface analysis to control system design. The target plant concept for the work described in this paper is the Power Reactor Inherently Safe Module reactor (PRISM), an advanced modular liquid metal reactor concept. This and other reactor designs which provide strong passive responses to operational upsets or accidents afford good opportunities to apply these advances in control technology. 18 refs., 5 figs.

  17. Control definition study for advanced vehicles

    NASA Technical Reports Server (NTRS)

    Lapins, M.; Martorella, R. P.; Klein, R. W.; Meyer, R. C.; Sturm, M. J.

    1983-01-01

    The low speed, high angle of attack flight mechanics of an advanced, canard-configured, supersonic tactical aircraft designed with moderate longitudinal relaxed static stability (Static Margin, SM = 16% C sub W at M = 0.4) was investigated. Control laws were developed for the longitudinal axis (""G'' or maneuver and angle of attack command systems) and for the lateral/directional axes. The performance of these control laws was examined in engineering simulation. A canard deflection/rate requirement study was performed as part of the ""G'' command law evaluation at low angles of attack. Simulated coupled maneuvers revealed the need for command limiters in all three aircraft axes to prevent departure from controlled flight. When modified with command/maneuver limiters, the control laws were shown to be adequate to prevent aircraft departure during aggressive air combat maneuvering.

  18. Advanced control design for hybrid turboelectric vehicle

    NASA Astrophysics Data System (ADS)

    Abban, Joseph; Norvell, Johnesta; Momoh, James A.

    1995-08-01

    The new environment standards are a challenge and opportunity for industry and government who manufacture and operate urban mass transient vehicles. A research investigation to provide control scheme for efficient power management of the vehicle is in progress. Different design requirements using functional analysis and trade studies of alternate power sources and controls have been performed. The design issues include portability, weight and emission/fuel efficiency of induction motor, permanent magnet and battery. A strategic design scheme to manage power requirements using advanced control systems is presented. It exploits fuzzy logic, technology and rule based decision support scheme. The benefits of our study will enhance the economic and technical feasibility of technological needs to provide low emission/fuel efficient urban mass transit bus. The design team includes undergraduate researchers in our department. Sample results using NASA HTEV simulation tool are presented.

  19. JPL Advanced Thermal Control Technology Roadmap - 2008

    NASA Technical Reports Server (NTRS)

    Birur, Gaj

    2008-01-01

    This slide presentation reviews the status of thermal control technology at JPL and NASA.It shows the active spacecraft that are in vairous positions in the solar syatem, and beyond the solar system and the future missions that are under development. It then describes the challenges that the past missions posed with the thermal control systems. The various solutions that were implemented duirng the decades prior to 1990 are outlined. A review of hte thermal challenges of the future misions is also included. The exploration plan for Mars is then reviewed. The thermal challenges of the Mars Rovers are then outlined. Also the challenges of systems that would be able to be used in to explore Venus, and Titan are described. The future space telescope missions will also need thermal control technological advances. Included is a review of the thermal requirements for manned missions to the Moon. Both Active and passive technologies that have been used and will be used are reviewed. Those that are described are Mechanically Pumped Fluid Loops (MPFL), Loop Heat Pipes, an M3 Passive Cooler, Heat Siwtch for Space and Mars surface applications, phase change material (PCM) technology, a Gas Gap Actuateor using ZrNiH(x), the Planck Sorption Cooler (PCS), vapor compression -- Hybrid two phase loops, advanced pumps for two phase cooling loops, and heat pumps that are lightweight and energy efficient.

  20. Intermittent control: a computational theory of human control.

    PubMed

    Gawthrop, Peter; Loram, Ian; Lakie, Martin; Gollee, Henrik

    2011-02-01

    The paradigm of continuous control using internal models has advanced understanding of human motor control. However, this paradigm ignores some aspects of human control, including intermittent feedback, serial ballistic control, triggered responses and refractory periods. It is shown that event-driven intermittent control provides a framework to explain the behaviour of the human operator under a wider range of conditions than continuous control. Continuous control is included as a special case, but sampling, system matched hold, an intermittent predictor and an event trigger allow serial open-loop trajectories using intermittent feedback. The implementation here may be described as "continuous observation, intermittent action". Beyond explaining unimodal regulation distributions in common with continuous control, these features naturally explain refractoriness and bimodal stabilisation distributions observed in double stimulus tracking experiments and quiet standing, respectively. Moreover, given that human control systems contain significant time delays, a biological-cybernetic rationale favours intermittent over continuous control: intermittent predictive control is computationally less demanding than continuous predictive control. A standard continuous-time predictive control model of the human operator is used as the underlying design method for an event-driven intermittent controller. It is shown that when event thresholds are small and sampling is regular, the intermittent controller can masquerade as the underlying continuous-time controller and thus, under these conditions, the continuous-time and intermittent controller cannot be distinguished. This explains why the intermittent control hypothesis is consistent with the continuous control hypothesis for certain experimental conditions. PMID:21327829

  1. Advanced nuclear plant control room complex

    DOEpatents

    Scarola, Kenneth; Jamison, David S.; Manazir, Richard M.; Rescorl, Robert L.; Harmon, Daryl L.

    1993-01-01

    An advanced control room complex for a nuclear power plant, including a discrete indicator and alarm system (72) which is nuclear qualified for rapid response to changes in plant parameters and a component control system (64) which together provide a discrete monitoring and control capability at a panel (14-22, 26, 28) in the control room (10). A separate data processing system (70), which need not be nuclear qualified, provides integrated and overview information to the control room and to each panel, through CRTs (84) and a large, overhead integrated process status overview board (24). The discrete indicator and alarm system (72) and the data processing system (70) receive inputs from common plant sensors and validate the sensor outputs to arrive at a representative value of the parameter for use by the operator during both normal and accident conditions, thereby avoiding the need for him to assimilate data from each sensor individually. The integrated process status board (24) is at the apex of an information hierarchy that extends through four levels and provides access at each panel to the full display hierarchy. The control room panels are preferably of a modular construction, permitting the definition of inputs and outputs, the man machine interface, and the plant specific algorithms, to proceed in parallel with the fabrication of the panels, the installation of the equipment and the generic testing thereof.

  2. Control theory for scanning probe microscopy revisited.

    PubMed

    Stirling, Julian

    2014-01-01

    We derive a theoretical model for studying SPM feedback in the context of control theory. Previous models presented in the literature that apply standard models for proportional-integral-derivative controllers predict a highly unstable feedback environment. This model uses features specific to the SPM implementation of the proportional-integral controller to give realistic feedback behaviour. As such the stability of SPM feedback for a wide range of feedback gains can be understood. Further consideration of mechanical responses of the SPM system gives insight into the causes of exciting mechanical resonances of the scanner during feedback operation. PMID:24778957

  3. Control theory for scanning probe microscopy revisited

    PubMed Central

    2014-01-01

    Summary We derive a theoretical model for studying SPM feedback in the context of control theory. Previous models presented in the literature that apply standard models for proportional-integral-derivative controllers predict a highly unstable feedback environment. This model uses features specific to the SPM implementation of the proportional-integral controller to give realistic feedback behaviour. As such the stability of SPM feedback for a wide range of feedback gains can be understood. Further consideration of mechanical responses of the SPM system gives insight into the causes of exciting mechanical resonances of the scanner during feedback operation. PMID:24778957

  4. Speech recognition in advanced rotorcraft - Using speech controls to reduce manual control overload

    NASA Technical Reports Server (NTRS)

    Vidulich, Michael A.; Bortolussi, Michael R.

    1988-01-01

    An experiment has been conducted to ascertain the usefulness of helicopter pilot speech controls and their effect on time-sharing performance, under the impetus of multiple-resource theories of attention which predict that time-sharing should be more efficient with mixed manual and speech controls than with all-manual ones. The test simulation involved an advanced, single-pilot scout/attack helicopter. Performance and subjective workload levels obtained supported the claimed utility of speech recognition-based controls; specifically, time-sharing performance was improved while preparing a data-burst transmission of information during helicopter hover.

  5. Use of modern control theory in military command and control

    NASA Astrophysics Data System (ADS)

    Busch, Timothy E.

    2001-09-01

    This paper discusses the use of modern control theoretic approaches in military command and control. The military enterprise is a highly dynamic and nonlinear environment. The desire on the part of military commanders to operate at faster operational tempos while still maintaining a stable and robust system, naturally leads to the consideration of a control theoretic approach to providing decision aids. I will present a brief history of the science of command and control of military forces and discuss how modern control theory might be applied to air operations.

  6. Advanced Wavefront Sensing and Control Testbed (AWCT)

    NASA Technical Reports Server (NTRS)

    Shi, Fang; Basinger, Scott A.; Diaz, Rosemary T.; Gappinger, Robert O.; Tang, Hong; Lam, Raymond K.; Sidick, Erkin; Hein, Randall C.; Rud, Mayer; Troy, Mitchell

    2010-01-01

    The Advanced Wavefront Sensing and Control Testbed (AWCT) is built as a versatile facility for developing and demonstrating, in hardware, the future technologies of wave front sensing and control algorithms for active optical systems. The testbed includes a source projector for a broadband point-source and a suite of extended scene targets, a dispersed fringe sensor, a Shack-Hartmann camera, and an imaging camera capable of phase retrieval wavefront sensing. The testbed also provides two easily accessible conjugated pupil planes which can accommodate the active optical devices such as fast steering mirror, deformable mirror, and segmented mirrors. In this paper, we describe the testbed optical design, testbed configurations and capabilities, as well as the initial results from the testbed hardware integrations and tests.

  7. A statistical rain attenuation prediction model with application to the advanced communication technology satellite project. 3: A stochastic rain fade control algorithm for satellite link power via non linear Markow filtering theory

    NASA Technical Reports Server (NTRS)

    Manning, Robert M.

    1991-01-01

    The dynamic and composite nature of propagation impairments that are incurred on Earth-space communications links at frequencies in and above 30/20 GHz Ka band, i.e., rain attenuation, cloud and/or clear air scintillation, etc., combined with the need to counter such degradations after the small link margins have been exceeded, necessitate the use of dynamic statistical identification and prediction processing of the fading signal in order to optimally estimate and predict the levels of each of the deleterious attenuation components. Such requirements are being met in NASA's Advanced Communications Technology Satellite (ACTS) Project by the implementation of optimal processing schemes derived through the use of the Rain Attenuation Prediction Model and nonlinear Markov filtering theory.

  8. Advanced mobile networking, sensing, and controls.

    SciTech Connect

    Feddema, John Todd; Kilman, Dominique Marie; Byrne, Raymond Harry; Young, Joseph G.; Lewis, Christopher L.; Van Leeuwen, Brian P.; Robinett, Rush D. III; Harrington, John J.

    2005-03-01

    This report describes an integrated approach for designing communication, sensing, and control systems for mobile distributed systems. Graph theoretic methods are used to analyze the input/output reachability and structural controllability and observability of a decentralized system. Embedded in each network node, this analysis will automatically reconfigure an ad hoc communication network for the sensing and control task at hand. The graph analysis can also be used to create the optimal communication flow control based upon the spatial distribution of the network nodes. Edge coloring algorithms tell us that the minimum number of time slots in a planar network is equal to either the maximum number of adjacent nodes (or degree) of the undirected graph plus some small number. Therefore, the more spread out that the nodes are, the fewer number of time slots are needed for communication, and the smaller the latency between nodes. In a coupled system, this results in a more responsive sensor network and control system. Network protocols are developed to propagate this information, and distributed algorithms are developed to automatically adjust the number of time slots available for communication. These protocols and algorithms must be extremely efficient and only updated as network nodes move. In addition, queuing theory is used to analyze the delay characteristics of Carrier Sense Multiple Access (CSMA) networks. This report documents the analysis, simulation, and implementation of these algorithms performed under this Laboratory Directed Research and Development (LDRD) effort.

  9. Performance of children and adolescents with Asperger syndrome or high-functioning autism on advanced theory of mind tasks.

    PubMed

    Kaland, Nils; Callesen, Kirsten; Møller-Nielsen, Annette; Mortensen, Erik Lykke; Smith, Lars

    2008-07-01

    Although a number of advanced theory of mind tasks have been developed, there is a dearth of information on whether performances on different tasks are associated. The present study examined the performance of 21 children and adolescents with diagnoses of Asperger syndrome (AS) and 20 typically developing controls on three advanced theory of mind tasks: The Eyes Task, the Strange Stories, and the Stories from Everyday Life. The participants in the clinical group demonstrated lower performance than the controls on all the three tasks. The pattern of findings, however, indicates that these tasks may share different information-processing requirements in addition to tapping different mentalizing abilities. PMID:18058213

  10. Health, wealth, and air pollution: advancing theory and methods.

    PubMed Central

    O'Neill, Marie S; Jerrett, Michael; Kawachi, Ichiro; Levy, Jonathan I; Cohen, Aaron J; Gouveia, Nelson; Wilkinson, Paul; Fletcher, Tony; Cifuentes, Luis; Schwartz, Joel

    2003-01-01

    The effects of both ambient air pollution and socioeconomic position (SEP) on health are well documented. A limited number of recent studies suggest that SEP may itself play a role in the epidemiology of disease and death associated with exposure to air pollution. Together with evidence that poor and working-class communities are often more exposed to air pollution, these studies have stimulated discussion among scientists, policy makers, and the public about the differential distribution of the health impacts from air pollution. Science and public policy would benefit from additional research that integrates the theory and practice from both air pollution and social epidemiologies to gain a better understanding of this issue. In this article we aim to promote such research by introducing readers to methodologic and conceptual approaches in the fields of air pollution and social epidemiology; by proposing theories and hypotheses about how air pollution and socioeconomic factors may interact to influence health, drawing on studies conducted worldwide; by discussing methodologic issues in the design and analysis of studies to determine whether health effects of exposure to ambient air pollution are modified by SEP; and by proposing specific steps that will advance knowledge in this field, fill information gaps, and apply research results to improve public health in collaboration with affected communities. PMID:14644658

  11. Sampling for advanced overlay process control

    NASA Astrophysics Data System (ADS)

    Choi, DongSub; Izikson, Pavel; Sutherland, Doug; Sherman, Kara; Manka, Jim; Robinson, John C.

    2008-03-01

    Overlay metrology and control have been critical for successful advanced microlithography for many years, and are taking on an even more important role as time goes on. Due to throughput constraints it is necessary to sample only a small subset of overlay metrology marks, and typical sample plans are static over time. Standard production monitoring and control involves measuring sufficient samples to calculate up to 6 linear correctables. As design rules shrink and processing becomes more complex, however, it is necessary to consider higher order modeled terms for control, fault detection, and disposition. This in turn, requires a higher level of sampling. Due to throughput concerns, however, careful consideration is needed to establish a base-line sampling, and higher levels of sampling can be considered on an exception-basis based on automated trigger mechanisms. The goal is improved scanner control and lithographic cost of ownership. This study addresses tools for establishing baseline sampling as well as motivation and initial results for dynamic sampling for application to higher order modeling.

  12. The Advanced Controls Program at Oak Ridge National Laboratory

    SciTech Connect

    Knee, H.E.; White, J.D.

    1990-01-01

    The Oak Ridge National Laboratory (ORNL), under sponsorship of the US Department of Energy (DOE), is conducting research that will lead to advanced, automated control of new liquid-metal-reactor (LMR) nuclear power plants. Although this program of research (entitled the Advanced Controls Program'') is focused on LMR technology, it will be capable of providing control design, test, and qualification capability for other advanced reactor designs (e.g., the advanced light water reactor (ALWR) and high temperature gas-cooled reactor (HTGR) designs), while also benefiting existing nuclear plants. The Program will also have applicability to complex, non-nuclear process control environments (e.g., petrochemical, aerospace, etc.). The Advanced Controls Program will support capabilities throughout the entire plant design life cycle, i.e., from the initial interactive first-principle dynamic model development for the process, systems, components, and instruments through advanced control room qualification. The current program involves five principal areas of research activities: (1) demonstrations of advanced control system designs, (2) development of an advanced controls design environment, (3) development of advanced control strategies, (4) research and development (R D) in human-system integration for advanced control system designs, and (5) testing and validation of advanced control system designs. Discussion of the research in these five areas forms the basis of this paper. Also included is a description of the research directions of the program. 8 refs.

  13. Advanced Emissions Control Development Program: Phase III

    SciTech Connect

    G.T. Amrhein; R.T. Bailey; W. Downs; M.J. Holmes; G.A. Kudlac; D.A. Madden

    1999-07-01

    The primary objective of the Advanced Emissions Control Development Program (AECDP) is to develop practical, cost-effective strategies for reducing the emissions of air toxics from coal-fired boilers. The project goal is to effectively control air toxic emissions through the use of conventional flue gas clean-up equipment such as electrostatic precipitators (ESPs), fabric filters (baghouses - BH), and wet flue gas desulfurization systems (WFGD). Development work concentrated on the capture of trace metals, fine particulate, hydrogen chloride and hydrogen fluoride, with an emphasis on the control of mercury. The AECDP project is jointly funded by the US Department of Energy's Federal Energy Technology Center (DOE), the Ohio Coal Development Office within the Ohio Department of Development (OCDO), and Babcock and Wilcox, a McDermott company (B and W). This report discusses results of all three phases of the AECDP project with an emphasis on Phase III activities. Following the construction and evaluation of a representative air toxics test facility in Phase I, Phase II focused on characterization of the emissions of mercury and other air toxics and the control of these emissions for typical operating conditions of conventional flue gas clean-up equipment. Some general comments that can be made about the control of air toxics while burning a high-sulfur bituminous coal are as follows: (1) particulate control devices such as ESP's and baghouses do a good job of removing non-volatile trace metals, (2) particulate control devices (ESPs and baghouses) effectively remove the particulate-phase mercury, but the particulate-phase mercury was only a small fraction of the total for the coals tested, (3) wet scrubbing can effectively remove hydrogen chloride and hydrogen fluoride, and (4) wet scrubbers show good potential for the removal of mercury when operated under certain conditions, however, for certain applications, system enhancements can be required to achieve high

  14. Sampling for advanced overlay process control

    NASA Astrophysics Data System (ADS)

    Kato, Cindy; Kurita, Hiroyuki; Izikson, Pavel; Robinson, John C.

    2009-03-01

    Overlay metrology and control have been critical for successful advanced microlithography for many years, and are taking on an even more important role as time goes on. Due to throughput constraints it is necessary to sample only a small subset of overlay metrology marks, and typical sample plans are static over time. Standard production monitoring and control involves measuring sufficient samples to calculate up to 6 linear correctables. As design rules shrink and processing becomes more complex, however, it is necessary to consider higher order models with additional degrees of freedom for control, fault detection, and disposition. This in turn, requires a higher level of sampling and a careful consideration of flyer removal. Due to throughput concerns, however, careful consideration is needed to establish a baseline sampling plan using rigorous statistical methods. This study focuses on establishing a 3x nm node immersion lithography production-worthy sampling plan for 3rd order modeling, verification of the accuracy, and proof of robustness of the sampling. In addition we discuss motivation for dynamic sampling for application to higher order modeling.

  15. Advanced Noise Control Fan Aerodynamic Performance

    NASA Technical Reports Server (NTRS)

    Bozak, Richard F., Jr.

    2009-01-01

    The Advanced Noise Control Fan at the NASA Glenn Research Center is used to experimentally analyze fan generated acoustics. In order to determine how a proposed noise reduction concept affects fan performance, flow measurements can be used to compute mass flow. Since tedious flow mapping is required to obtain an accurate mass flow, an equation was developed to correlate the mass flow to inlet lip wall static pressure measurements. Once this correlation is obtained, the mass flow for future configurations can be obtained from the nonintrusive wall static pressures. Once the mass flow is known, the thrust and fan performance can be evaluated. This correlation enables fan acoustics and performance to be obtained simultaneously without disturbing the flow.

  16. Advanced control strategy for plant heat rate improvement

    SciTech Connect

    Schultz, P.; Frerichs, D.K.; Kyr, D.

    1995-12-31

    Florida Power & Light Company (FPL) supplies electricity to about half of the population of Florida, roughly 6.5 million people. The load base is largely residential/business with the obvious seasonal extremes due to the climate. FPL`s generating capacity is 16,320 MW composed of 70% traditional fossil cycle, 18% nuclear, and 12% gas turbine. The system load profile coupled with bulk power purchases is such that the 400 MW class units (9 Foster Wheeler drum type units comprising 24% of total capacity) are now forced to cycle daily all year, and to come off line on weekends during the winter months. The current economic realities of power generation force utility companies to seek methods to improve plant heat rate, and FPL is no exception. FPL believed it possible to achieve the goal of lower heat rate and follow the required load demand with the 400 MW class units through the use of an advanced control strategy implemented totally within the unit`s Distributed Control System (DCS). As of the writing of this paper, the project is still ongoing. This paper will present the theory and methodology of the advanced control strategy along with the current design and implementation status and results obtained to date.

  17. Control Software for Advanced Video Guidance Sensor

    NASA Technical Reports Server (NTRS)

    Howard, Richard T.; Book, Michael L.; Bryan, Thomas C.

    2006-01-01

    Embedded software has been developed specifically for controlling an Advanced Video Guidance Sensor (AVGS). A Video Guidance Sensor is an optoelectronic system that provides guidance for automated docking of two vehicles. Such a system includes pulsed laser diodes and a video camera, the output of which is digitized. From the positions of digitized target images and known geometric relationships, the relative position and orientation of the vehicles are computed. The present software consists of two subprograms running in two processors that are parts of the AVGS. The subprogram in the first processor receives commands from an external source, checks the commands for correctness, performs commanded non-image-data-processing control functions, and sends image data processing parts of commands to the second processor. The subprogram in the second processor processes image data as commanded. Upon power-up, the software performs basic tests of functionality, then effects a transition to a standby mode. When a command is received, the software goes into one of several operational modes (e.g. acquisition or tracking). The software then returns, to the external source, the data appropriate to the command.

  18. EDITORIAL: Quantum control theory for coherence and information dynamics Quantum control theory for coherence and information dynamics

    NASA Astrophysics Data System (ADS)

    Viola, Lorenza; Tannor, David

    2011-08-01

    Precisely characterizing and controlling the dynamics of realistic open quantum systems has emerged in recent years as a key challenge across contemporary quantum sciences and technologies, with implications ranging from physics, chemistry and applied mathematics to quantum information processing (QIP) and quantum engineering. Quantum control theory aims to provide both a general dynamical-system framework and a constructive toolbox to meet this challenge. The purpose of this special issue of Journal of Physics B: Atomic, Molecular and Optical Physics is to present a state-of-the-art account of recent advances and current trends in the field, as reflected in two international meetings that were held on the subject over the last summer and which motivated in part the compilation of this volume—the Topical Group: Frontiers in Open Quantum Systems and Quantum Control Theory, held at the Institute for Theoretical Atomic, Molecular and Optical Physics (ITAMP) in Cambridge, Massachusetts (USA), from 1-14 August 2010, and the Safed Workshop on Quantum Decoherence and Thermodynamics Control, held in Safed (Israel), from 22-27 August 2010. Initial developments in quantum control theory date back to (at least) the early 1980s, and have been largely inspired by the well-established mathematical framework for classical dynamical systems. As the above-mentioned meetings made clear, and as the burgeoning body of literature on the subject testifies, quantum control has grown since then well beyond its original boundaries, and has by now evolved into a highly cross-disciplinary field which, while still fast-moving, is also entering a new phase of maturity, sophistication, and integration. Two trends deserve special attention: on the one hand, a growing emphasis on control tasks and methodologies that are specifically motivated by QIP, in addition and in parallel to applications in more traditional areas where quantum coherence is nevertheless vital (such as, for instance

  19. Aerospace plane guidance using geometric control theory

    NASA Technical Reports Server (NTRS)

    Van Buren, Mark A.; Mease, Kenneth D.

    1990-01-01

    A reduced-order method employing decomposition, based on time-scale separation, of the 4-D state space in a 2-D slow manifold and a family of 2-D fast manifolds is shown to provide an excellent approximation to the full-order minimum-fuel ascent trajectory. Near-optimal guidance is obtained by tracking the reduced-order trajectory. The tracking problem is solved as regulation problems on the family of fast manifolds, using the exact linearization methodology from nonlinear geometric control theory. The validity of the overall guidance approach is indicated by simulation.

  20. Recent advances in percolation theory and its applications

    NASA Astrophysics Data System (ADS)

    Saberi, Abbas Ali

    2015-05-01

    Percolation is the simplest fundamental model in statistical mechanics that exhibits phase transitions signaled by the emergence of a giant connected component. Despite its very simple rules, percolation theory has successfully been applied to describe a large variety of natural, technological and social systems. Percolation models serve as important universality classes in critical phenomena characterized by a set of critical exponents which correspond to a rich fractal and scaling structure of their geometric features. We will first outline the basic features of the ordinary model. Over the years a variety of percolation models has been introduced some of which with completely different scaling and universal properties from the original model with either continuous or discontinuous transitions depending on the control parameter, dimensionality and the type of the underlying rules and networks. We will try to take a glimpse at a number of selective variations including Achlioptas process, half-restricted process and spanning cluster-avoiding process as examples of the so-called explosive percolation. We will also introduce non-self-averaging percolation and discuss correlated percolation and bootstrap percolation with special emphasis on their recent progress. Directed percolation process will be also discussed as a prototype of systems displaying a nonequilibrium phase transition into an absorbing state. In the past decade, after the invention of stochastic Löwner evolution (SLE) by Oded Schramm, two-dimensional (2D) percolation has become a central problem in probability theory leading to the two recent Fields medals. After a short review on SLE, we will provide an overview on existence of the scaling limit and conformal invariance of the critical percolation. We will also establish a connection with the magnetic models based on the percolation properties of the Fortuin-Kasteleyn and geometric spin clusters. As an application we will discuss how percolation

  1. Response Times of Children and Adolescents with Asperger Syndrome on an "Advanced" Test of Theory of Mind

    ERIC Educational Resources Information Center

    Kaland, Nils; Smith, Lars; Mortensen, Erik Lykke

    2007-01-01

    In the present study the response times of 10- to 20-year-old participants with Asperger syndrome (AS) (N = 21) of normal intelligence and a control group of typically developing individuals (N = 20) were recorded on a new "advanced" test of theory of mind. This test taps the ability to make mental-state inferences versus physical-state inferences…

  2. Advanced Control and Power System (ACAPS) Technology Program

    NASA Technical Reports Server (NTRS)

    Keckler, C. R.; Groom, N. J.

    1983-01-01

    The advanced control and power system (ACAPS) program is to establish the technology necessary to satisfy space station and related large space structures requirements for efficient, reliable, and cost effective energy storage and attitude control. Technology advances in the area of integrated flywheel systems capable of performing the dual functions of energy storage and attitude control are outlined.

  3. Structureborne noise control in advanced turboprop aircraft

    NASA Astrophysics Data System (ADS)

    Loeffler, Irvin J.

    1987-01-01

    Structureborne noise is discussed as a contributor to propeller aircraft interior noise levels that are nonresponsive to the application of a generous amount of cabin sidewall acoustic treatment. High structureborne noise levels may jeopardize passenger acceptance of the fuel-efficient high-speed propeller transport aircraft designed for cruise at Mach 0.65 to 0.85. These single-rotation tractor and counter-rotation tractor and pusher propulsion systems will consume 15 to 30 percent less fuel than advanced turbofan systems. Structureborne noise detection methodologies and the importance of development of a structureborne noise sensor are discussed. A structureborne noise generation mechanism is described in which the periodic components or propeller swirl produce periodic torques and forces on downstream wings and airfoils that are propagated to the cabin interior as noise. Three concepts for controlling structureborne noise are presented: (1) a stator row swirl remover, (2) selection of a proper combination of blade numbers in the rotor/stator system of a single-rotation propeller, and the rotor/rotor system of a counter-rotation propeller, and (3) a tuned mechanical absorber.

  4. Impact of Advance Control on Microturbine Generation System Performance

    NASA Astrophysics Data System (ADS)

    Kamil Mat Hussin, Ahmad; Zamri Che Wanik, Mohd

    2013-06-01

    Advance control employed in microturbine generation system (MTGS) is expected to improve its performance in responding to grid faults. This paper compares the effect of advance control of MTGS power conversion topology on the performance in riding through the grid faults. The analysis and investigation study through simulation shows there is no significant different on MTGS output performance even advance control is employed for its rectifier.

  5. Advancing cancer control research in an emerging news media environment.

    PubMed

    Smith, Katherine C; Niederdeppe, Jeff; Blake, Kelly D; Cappella, Joseph N

    2013-12-01

    Cancer is both highly feared and highly newsworthy, and there is a robust body of research documenting the content and effects of cancer news coverage on health behaviors and policy. Recent years have witnessed ongoing, transformative shifts in American journalism alongside rapid advances in communication technology and the public information environment. These changes create a pressing need to consider a new set of research questions, sampling strategies, measurement techniques, and theories of media effects to ensure continued relevance and adaptation of communication research to address critical cancer control concerns. This paper begins by briefly reviewing what we know about the role of cancer news in shaping cancer-related beliefs, attitudes, behaviors, and policies. We then outline challenges and opportunities, both theoretical and methodological, posed by the rapidly changing news media environment and the nature of audience engagement. We organize our discussion around three major shifts associated with the emerging news media environment as it relates to health communication: 1) speed and dynamism of news diffusion, 2) increased narrowcasting of media content for specialized audiences, and 3) broadened participation in shaping media content. In so doing, we articulate a set of questions for future theory and research, in an effort to catalyze innovative communication scholarship to improve cancer prevention and control. PMID:24395988

  6. Expansion of Perturbation Theory Applied to Shim Rotation Automation of the Advanced Test Reactor

    NASA Astrophysics Data System (ADS)

    Peterson, Joshua Loren

    In 2007, the Department of Energy (DOE) declared the Advanced Test Reactor (ATR) a National Scientific User Facility (NSUF). This declaration expanded the focus of the ATR to include diversified classes of academic and industrial experiments. An essential part of the new suite of more accurate and flexible codes being deployed to support the NSUF is their ability to predict reactor behavior at startup, particularly the position of the outer shim control cylinders (OSCC). The current method used for calculating the OSCC positions during a cycle startup utilizes a heuristic trial and error approach that is impractical with the computationally intensive reactor physics tools, such as NEWT. It is therefore desirable that shim rotation prediction for startup be automated. Shim rotation prediction with perturbation theory was chosen to be investigated as one method for use with startup calculation automation. A modified form of first order perturbation theory, called phase space interpolated perturbation theory, was developed to more accurately model shim rotation prediction. Shim rotation prediction is just one application for this new modified form of perturbation theory. Phase space interpolated perturbation theory can be used on any application where the range of change to the system is known a priori, but the magnitude of change is not known. A cubic regression method was also developed to automate shim rotation prediction by using only forward solutions to the transport equation.

  7. Stimulus-responsive hydrogels: Theory, modern advances, and applications

    PubMed Central

    Koetting, Michael C.; Peters, Jonathan T.; Steichen, Stephanie D.; Peppas, Nicholas A.

    2016-01-01

    Over the past century, hydrogels have emerged as effective materials for an immense variety of applications. The unique network structure of hydrogels enables very high levels of hydrophilicity and biocompatibility, while at the same time exhibiting the soft physical properties associated with living tissue, making them ideal biomaterials. Stimulus-responsive hydrogels have been especially impactful, allowing for unprecedented levels of control over material properties in response to external cues. This enhanced control has enabled groundbreaking advances in healthcare, allowing for more effective treatment of a vast array of diseases and improved approaches for tissue engineering and wound healing. In this extensive review, we identify and discuss the multitude of response modalities that have been developed, including temperature, pH, chemical, light, electro, and shear-sensitive hydrogels. We discuss the theoretical analysis of hydrogel properties and the mechanisms used to create these responses, highlighting both the pioneering and most recent work in all of these fields. Finally, we review the many current and proposed applications of these hydrogels in medicine and industry. PMID:27134415

  8. Aerodynamic shape optimization using control theory

    NASA Technical Reports Server (NTRS)

    Reuther, James

    1996-01-01

    Aerodynamic shape design has long persisted as a difficult scientific challenge due its highly nonlinear flow physics and daunting geometric complexity. However, with the emergence of Computational Fluid Dynamics (CFD) it has become possible to make accurate predictions of flows which are not dominated by viscous effects. It is thus worthwhile to explore the extension of CFD methods for flow analysis to the treatment of aerodynamic shape design. Two new aerodynamic shape design methods are developed which combine existing CFD technology, optimal control theory, and numerical optimization techniques. Flow analysis methods for the potential flow equation and the Euler equations form the basis of the two respective design methods. In each case, optimal control theory is used to derive the adjoint differential equations, the solution of which provides the necessary gradient information to a numerical optimization method much more efficiently then by conventional finite differencing. Each technique uses a quasi-Newton numerical optimization algorithm to drive an aerodynamic objective function toward a minimum. An analytic grid perturbation method is developed to modify body fitted meshes to accommodate shape changes during the design process. Both Hicks-Henne perturbation functions and B-spline control points are explored as suitable design variables. The new methods prove to be computationally efficient and robust, and can be used for practical airfoil design including geometric and aerodynamic constraints. Objective functions are chosen to allow both inverse design to a target pressure distribution and wave drag minimization. Several design cases are presented for each method illustrating its practicality and efficiency. These include non-lifting and lifting airfoils operating at both subsonic and transonic conditions.

  9. Cooperative control theory and integrated flight and propulsion control

    NASA Technical Reports Server (NTRS)

    Schmidt, David K.; Schierman, John D.

    1994-01-01

    This report documents the activities and research results obtained under a grant (NAG3-998) from the NASA Lewis Research Center. The focus of the research was the investigation of dynamic interactions between airframe and engines for advanced ASTOVL aircraft configurations, and the analysis of the implications of these interactions on the stability and performance of the airframe and engine control systems. In addition, the need for integrated flight and propulsion control for such aircraft was addressed. The major contribution of this research was the exposition of the fact that airframe and engine interactions could be present, and their effects could include loss of stability and performance of the control systems. Also, the significance of two directional, as opposed to one-directional, coupling was identified and explained. A multi variable stability and performance analysis methodology was developed, and applied to several candidate aircraft configurations. Also exposed was the fact that with interactions present along with some integrated control approaches, the engine command/limiting logic (which represents an important non-linear component of the engine control system) can impact closed-loop airframe/engine system stability. Finally, a brief investigation of control-law synthesis techniques appropriate for the class of systems was pursued, and it was determined that multi variable techniques, included model-following formulations of LQG and/or H (infinity) methods showed promise. However, for practical reasons, decentralized control architectures are preferred, which is an architecture incompatible with these synthesis methods.

  10. Dual-Process Theories and Cognitive Development: Advances and Challenges

    ERIC Educational Resources Information Center

    Barrouillet, Pierre

    2011-01-01

    Dual-process theories have gained increasing importance in psychology. The contrast that they describe between an old intuitive and a new deliberative mind seems to make these theories especially suited to account for development. Accordingly, this special issue aims at presenting the latest applications of dual-process theories to cognitive…

  11. Curriculum for the Twenty-First Century: Recent Advances in Economic Theory and Undergraduate Economics

    ERIC Educational Resources Information Center

    Ferguson, William D.

    2011-01-01

    Undergraduate economics lags behind cutting-edge economic theory. The author briefly reviews six related advances that profoundly extend and deepen economic analysis: game-theoretic modeling, collective-action problems, information economics and contracting, social preference theory, conceptualizing rationality, and institutional theory. He offers…

  12. Application of control theory to dynamic systems simulation

    NASA Technical Reports Server (NTRS)

    Auslander, D. M.; Spear, R. C.; Young, G. E.

    1982-01-01

    The application of control theory is applied to dynamic systems simulation. Theory and methodology applicable to controlled ecological life support systems are considered. Spatial effects on system stability, design of control systems with uncertain parameters, and an interactive computing language (PARASOL-II) designed for dynamic system simulation, report quality graphics, data acquisition, and simple real time control are discussed.

  13. Advanced control technology for LSST antennas

    NASA Technical Reports Server (NTRS)

    Lin, Y. H.

    1981-01-01

    The control technology for the realization of large space system technology (LSST) antenna systems was identified and developed. Emphasis was directed at the control of LSST wrap-rib offset-feed antenna. The overall dynamic and control performance of offset-feed antenna was evaluated. Quantitative definitions of control problems were provided and control concepts for future development were identified.

  14. Stability theory applications to laminar-flow control

    NASA Technical Reports Server (NTRS)

    Malik, Mujeeb R.

    1987-01-01

    In order to design Laminar Flow Control (LFC) configurations, reliable methods are needed for boundary-layer transition predictions. Among the available methods, there are correlations based upon R sub e, shape factors, Goertler number and crossflow Reynolds number. The most advanced transition prediction method is based upon linear stability theory in the form of the e sup N method which has proven to be successful in predicting transition in two- and three-dimensional boundary layers. When transition occurs in a low disturbance environment, the e sup N method provides a viable design tool for transition prediction and LFC in both 2-D and 3-D subsonic/supersonic flows. This is true for transition dominated by either TS, crossflow, or Goertler instability. If Goertler/TS or crossflow/TS interaction is present, the e sup N will fail to predict transition. However, there is no evidence of such interaction at low amplitudes of Goertler and crossflow vortices.

  15. Open architecture controllers for advanced manufacturing

    SciTech Connect

    Gore, R.A.

    1994-03-01

    The application of intelligent control systems to the real world of machining and manufacturing will benefit form the presence of open architecture control systems on the machines or the processes. The ability to modify the control system as the process or product changes can be essential to the success of the application of neural net or fuzzy logic controllers. The effort at Los Alamos to obtain a commercially available open architecture machine tool controller is described.

  16. Experiment-Based Teaching in Advanced Control Engineering

    ERIC Educational Resources Information Center

    Precup, R.-E.; Preitl, S.; Radac, M.-B.; Petriu, E. M.; Dragos, C.-A.; Tar, J. K.

    2011-01-01

    This paper discusses an experiment-based approach to teaching an advanced control engineering syllabus involving controlled plant analysis and modeling, control structures and algorithms, real-time laboratory experiments, and their assessment. These experiments are structured around the representative case of the longitudinal slip control of an…

  17. Advanced control technology for LSST platform

    NASA Technical Reports Server (NTRS)

    Edmunds, R. S.

    1981-01-01

    Basic technology in the design, mechanization, and analysis of control systems for large flexible space structures was examined. The focus of the platform control effort was on pointing control. The reason for this emphasis was because of the unique problems in this area posed by multiple independent experiment packages operating simultaneously on a single platform. Attitude control and stationkeeping were also addressed for future consideration.

  18. Smart Engines Via Advanced Model Based Controls

    SciTech Connect

    Allain, Marc

    2000-08-20

    A ''new'' process for developing control systems - Less engine testing - More robust control system - Shorter development cycle time - ''Smarter'' approach to engine control - On-board models describe engine behavior - Shorter, systematic calibration process - Customer and legislative requirements designed-in.

  19. Controlling template erosion with advanced cleaning methods

    NASA Astrophysics Data System (ADS)

    Singh, SherJang; Yu, Zhaoning; Wähler, Tobias; Kurataka, Nobuo; Gauzner, Gene; Wang, Hongying; Yang, Henry; Hsu, Yautzong; Lee, Kim; Kuo, David; Dress, Peter

    2012-03-01

    We studied the erosion and feature stability of fused silica patterns under different template cleaning conditions. The conventional SPM cleaning is compared with an advanced non-acid process. Spectroscopic ellipsometry optical critical dimension (SE-OCD) measurements were used to characterize the changes in pattern profile with good sensitivity. This study confirmed the erosion of the silica patterns in the traditional acid-based SPM cleaning mixture (H2SO4+H2O2) at a rate of ~0.1nm per cleaning cycle. The advanced non-acid clean process however only showed CD shift of ~0.01nm per clean. Contamination removal & pattern integrity of sensitive 20nm features under MegaSonic assisted cleaning is also demonstrated.

  20. Advanced control evaluation for structures (ACES) programs

    NASA Technical Reports Server (NTRS)

    Pearson, Jerome; Waites, Henry

    1988-01-01

    The ACES programs are a series of past, present, and future activities at the Marshall Space Flight Center (MSFC) Ground facility for Large Space Structure Control Verification (GF/LSSCV). The main objectives of the ACES programs are to implement control techniques on a series of complex dynamical systems, to determine the control/structure interaction for the control techniques, and to provide a national facility in which dynamics and control verification can be effected. The focus is on these objectives and how they are implemented under various engineering and economic constraints. Future plans that will be effected in upcoming ACES programs are considered.

  1. Advanced control strategies for fluidized bed dryers

    SciTech Connect

    Siettos, C.I.; Kiranoudis, C.T.; Bafas, G.V.

    1999-11-01

    Generating the best possible control strategy comprises a necessity for industrial processes, by virtue of product quality, cost reduction and design simplicity. Three different control approaches, namely an Input-Output linearizing, a fuzzy logic and a PID controller, are evaluated for the control of a fluidized bed dryer, a typical non-linear drying process of wide applicability. Based on several closed loop characteristics such as settling times, maximum overshoots and dynamic performance criteria such as IAE, ISE and ITAE, it is shown that the Input-Output linearizing and the fuzzy logic controller exhibit a better performance compared to the PID controller tuned optimally with respect to IAE, for a wide range of disturbances; yet, the relevant advantage of the fuzzy logic over the conventional nonlinear controller issues upon its design simplicity. Typical load rejection and set-point tracking examples are given to illustrate the effectiveness of the proposed approach.

  2. Robust control systems design by H-infinity optimization theory

    NASA Technical Reports Server (NTRS)

    Chang, B. C.; Li, X. P.; Banda, S. S.; Yeh, H. H.

    1991-01-01

    In this paper, step-by-step procedures of applying the H-infinity theory to robust control systems design are given. The objective of the paper is to eliminate the possible difficulties a control engineer may encounter in applying H-infinity control theory and to clear up some misconceptions about H-infinity theory like high-gain controller and numerical obstacles, etc. An efficient algorithm is used to compute the optimal H-infinity norm. The Glover and Doyle (1988) controller formulas are slightly modified and used to construct an optimal controller without any numerical difficulties.

  3. Advanced rotorcraft control using parameter optimization

    NASA Technical Reports Server (NTRS)

    Vansteenwyk, Brett; Ly, Uy-Loi

    1991-01-01

    A reliable algorithm for the evaluation of a quadratic performance index and its gradients with respect to the controller design parameters is presented. The algorithm is part of a design algorithm for an optimal linear dynamic output feedback controller that minimizes a finite time quadratic performance index. The numerical scheme is particularly robust when it is applied to the control law synthesis for systems with densely packed modes and where there is a high likelihood of encountering degeneracies in the closed loop eigensystem. This approach through the use of a accurate Pade series approximation does not require the closed loop system matrix to be diagonalizable. The algorithm has been included in a control design package for optimal robust low order controllers. Usefulness of the proposed numerical algorithm has been demonstrated using numerous practical design cases where degeneracies occur frequently in the closed loop system under an arbitrary controller design initialization and during the numerical search.

  4. Project T.E.A.M. (Technical Education Advancement Modules). Advanced Statistical Process Control.

    ERIC Educational Resources Information Center

    Dunlap, Dale

    This instructional guide, one of a series developed by the Technical Education Advancement Modules (TEAM) project, is a 20-hour advanced statistical process control (SPC) and quality improvement course designed to develop the following competencies: (1) understanding quality systems; (2) knowing the process; (3) solving quality problems; and (4)…

  5. Model-free adaptive control of advanced power plants

    SciTech Connect

    Cheng, George Shu-Xing; Mulkey, Steven L.; Wang, Qiang

    2015-08-18

    A novel 3-Input-3-Output (3.times.3) Model-Free Adaptive (MFA) controller with a set of artificial neural networks as part of the controller is introduced. A 3.times.3 MFA control system using the inventive 3.times.3 MFA controller is described to control key process variables including Power, Steam Throttle Pressure, and Steam Temperature of boiler-turbine-generator (BTG) units in conventional and advanced power plants. Those advanced power plants may comprise Once-Through Supercritical (OTSC) Boilers, Circulating Fluidized-Bed (CFB) Boilers, and Once-Through Supercritical Circulating Fluidized-Bed (OTSC CFB) Boilers.

  6. Advanced Combustion and Emission Control Technical Team Roadmap

    SciTech Connect

    2013-06-01

    The Advanced Combustion and Emission Control (ACEC) Technical Team is focused on removing technical barriers to the commercialization of advanced, high-efficiency, emission-compliant internal combustion (IC) engines for light-duty vehicle powertrains (i.e., passenger car, minivan, SUV, and pickup trucks).

  7. Alaskan glaciers: Recent observations in respect to the earthquake-advance theory

    USGS Publications Warehouse

    Post, A.S.

    1965-01-01

    Preliminary aerial photographic studies indicate that the Alaskan earthquake produced some rockfalls but no significant snow and ice avalanches on glaciers. No rapid, short-lived glacier advances (surges) are conclusively associated with this earthquake. Recent evidence fails to support the earthquake-advance theory of Tarr and Martin.

  8. Do Deaf Adults with Limited Language Have Advanced Theory of Mind?

    ERIC Educational Resources Information Center

    Hao, Jian; Su, Yanjie; Chan, Raymond C. K.

    2010-01-01

    Previous studies show that deaf children have deficits in false belief understanding due to their language impairment. However, it is not clear whether deaf adults still have problems in advanced theory of mind (ToM). The present study examined deaf adults' performance on three aspects of advanced ToM. All of the deaf groups lacking mental state…

  9. Advanced dc-Traction-Motor Control System

    NASA Technical Reports Server (NTRS)

    Vittone, O.

    1985-01-01

    Motor-control concept for battery-powered vehicles includes stateof-the-art power-transistor switching and separate excitation of motor windings in traction and regenerative braking. Switching transistors and other components of power-conditioning subsystem operate under control of computer that coordinates traction, braking, and protective functions.

  10. Early Childhood Community School Linkages: Advancing a Theory of Change

    ERIC Educational Resources Information Center

    Geiser, Kristin E.; Rollins, S. Kwesi; Gerstein, Amy; Blank, Martin J.

    2013-01-01

    In 2009, the Coalition for Community Schools at the Institute for Educational Leadership (CCS-IEL) embarked on an ambitious action research and development project, leveraging the community school system infrastructure present in three geographic regions (Tulsa, Oklahoma; Multnomah County, Oregon; Albuquerque, New Mexico) to advance research and…

  11. A New Computerised Advanced Theory of Mind Measure for Children with Asperger Syndrome: The ATOMIC

    ERIC Educational Resources Information Center

    Beaumont, Renae B.; Sofronoff, Kate

    2008-01-01

    This study examined the ability of children with Asperger Syndrome (AS) to attribute mental states to characters in a new computerised, advanced theory of mind measure: The Animated Theory of Mind Inventory for Children (ATOMIC). Results showed that children with AS matched on IQ, verbal comprehension, age and gender performed equivalently on…

  12. The ATF (Advanced Toroidal Facility) Status and Control System

    SciTech Connect

    Baylor, L.R.; Devan, W.R.; Sumner, J.N.; Alban, A.M.

    1987-01-01

    The Advanced Toroidal Facility (ATF) Status and Control System (SCS) is a programmable controller-based state monitoring and supervisory control system. This paper describes the SCS implementation and its use of a host computer to run a commercially available software package that provides color graphic interactive displays, alarm logging, and archiving of state data.

  13. Status report on the Advanced Light Source control system

    SciTech Connect

    Magyary, S.; Chin, M.; Fahmie, M.; Lancaster, H.; Molinari, P.; Robb, A.; Timossi, C.; Young, J.

    1991-11-11

    This paper is a status report on the ADVANCED LIGHT SOURCE (ALS) control system. The current status, performance data, and future plans will be discussed. Manpower, scheduling, and costs issues are addressed.

  14. Advanced Topics in Wet-Weather Discharge Control

    EPA Science Inventory

    This report discusses four related but generally independent wet-weather flow (WWF) topic areas, namely: i) opportunities for advanced practices in WWF control technology, particularly as it applies to sewered systems; ii) tradeoffs between storage facilities (tanks) and enlarged...

  15. Attitude Control Subsystem for the Advanced Communications Technology Satellite

    NASA Technical Reports Server (NTRS)

    Hewston, Alan W.; Mitchell, Kent A.; Sawicki, Jerzy T.

    1996-01-01

    This paper provides an overview of the on-orbit operation of the Attitude Control Subsystem (ACS) for the Advanced Communications Technology Satellite (ACTS). The three ACTS control axes are defined, including the means for sensing attitude and determining the pointing errors. The desired pointing requirements for various modes of control as well as the disturbance torques that oppose the control are identified. Finally, the hardware actuators and control loops utilized to reduce the attitude error are described.

  16. Advanced control concepts. [for shuttle ascent vehicles

    NASA Technical Reports Server (NTRS)

    Sharp, J. B.; Coppey, J. M.

    1973-01-01

    The problems of excess control devices and insufficient trim control capability on shuttle ascent vehicles were investigated. The trim problem is solved at all time points of interest using Lagrangian multipliers and a Simplex based iterative algorithm developed as a result of the study. This algorithm has the capability to solve any bounded linear problem with physically realizable constraints, and to minimize any piecewise differentiable cost function. Both solution methods also automatically distribute the command torques to the control devices. It is shown that trim requirements are unrealizable if only the orbiter engines and the aerodynamic surfaces are used.

  17. Advancing Social Justice in Vocational Theory, Research, and Practice

    ERIC Educational Resources Information Center

    Borgen, Fred H.

    2005-01-01

    David Blustein, Ellen Hawley McWhirter, and Justin Perry present a social justice agenda for action in vocational psychology in their article "An Emancipatory Communitarian Approach to Vocational Development Theory, Research, and Practice." They build on robust work in counseling psychology over recent decades by using the critical work of Isaac…

  18. Toward A Multilevel Theory of Career Development: Advancing Human Resource Development Theory Building

    ERIC Educational Resources Information Center

    Upton, Matthew G.; Egan, Toby Marshall

    2007-01-01

    The established limitations of career development (CD) theory and human resource development (HRD) theory building are addressed by expanding the framing of these issues to multilevel contexts. Multilevel theory building is an approach most effectively aligned with HRD literature and CD and HRD practice realities. An innovative approach multilevel…

  19. Advanced gel propulsion controls for kill vehicles

    NASA Astrophysics Data System (ADS)

    Yasuhara, W. K.; Olson, A.; Finato, S.

    1993-06-01

    A gel propulsion control concept for tactical applications is reviewed, and the status of the individual component technologies currently under development at the Aerojet Propulsion Division is discussed. It is concluded that a gel propellant Divert and Attitude Control Subsystem (DACS) provides a safe, insensitive munitions compliant alternative to current liquid Theater Missile Defense (TMD) DACS approaches. The gel kill vehicle (KV) control system packages a total impulse typical of a tactical weapon interceptor for the ground- or sea-based TMD systems. High density packaging makes it possible to increase firepower and to eliminate long-term high pressure gas storage associated with bipropellant systems. The integrated control subsystem technologies encompass solid propellant gas generators, insulated composite overwrapped propellant tanks, lightweight endoatmospheric thrusters, and insensitive munition gel propellants, which meet the requirements of a deployable, operationally safe KV.

  20. Theory of automatic control of airplanes

    NASA Technical Reports Server (NTRS)

    Weiss, Herbert K

    1939-01-01

    Methods of automatically controlling the airplane are reviewed. Equations for the controlled motion including inertia effects of the control are developed and methods of investigating the stability of the resulting fifth and higher order equations are presented. The equations for longitudinal and lateral motion with both ideal and non-ideal controls are developed in dimensionless form in terms of control parameters based on simple dynamic tests of the isolated control unit.

  1. Relationships between digital signal processing and control and estimation theory

    NASA Technical Reports Server (NTRS)

    Willsky, A. S.

    1978-01-01

    Research directions in the fields of digital signal processing and modern control and estimation theory are discussed. Stability theory, linear prediction and parameter identification, system synthesis and implementation, two-dimensional filtering, decentralized control and estimation, and image processing are considered in order to uncover some of the basic similarities and differences in the goals, techniques, and philosophy of the disciplines.

  2. The importance of behavior theory in control system modeling of physical activity sensor data.

    PubMed

    Riley, William T; Martin, Cesar A; Rivera, Daniel E

    2014-01-01

    Among health behaviors, physical activity has the most extensive record of research using passive sensors. Control systems and other system dynamic approaches have long been considered applicable for understanding human behavior, but only recently has the technology provided the precise and intensive longitudinal data required for these analytic approaches. Although sensors provide intensive data on the patterns and variations of physical activity over time, the influences of these variations are often unmeasured. Health behavior theories provide an explanatory framework of the putative mediators of physical activity changes. Incorporating the intensive longitudinal measurement of these theoretical constructs is critical to improving the fit of control system model of physical activity and for advancing behavioral theory. Theory-based control models also provide guidance on the nature of the controllers which serve as the basis for just-in-time adaptive interventions based on these control system models. PMID:25571577

  3. Control of Smart Building Using Advanced SCADA

    NASA Astrophysics Data System (ADS)

    Samuel, Vivin Thomas

    For complete control of the building, a proper SCADA implementation and the optimization strategy has to be build. For better communication and efficiency a proper channel between the Communication protocol and SCADA has to be designed. This paper concentrate mainly between the communication protocol, and the SCADA implementation, for a better optimization and energy savings is derived to large scale industrial buildings. The communication channel used in order to completely control the building remotely from a distant place. For an efficient result we consider the temperature values and the power ratings of the equipment so that while controlling the equipment, we are setting a threshold values for FDD technique implementation. Building management system became a vital source for any building to maintain it and for safety purpose. Smart buildings, refers to various distinct features, where the complete automation system, office building controls, data center controls. ELC's are used to communicate the load values of the building to the remote server from a far location with the help of an Ethernet communication channel. Based on the demand fluctuation and the peak voltage, the loads operate differently increasing the consumption rate thus results in the increase in the annual consumption bill. In modern days, saving energy and reducing the consumption bill is most essential for any building for a better and long operation. The equipment - monitored regularly and optimization strategy is implemented for cost reduction automation system. Thus results in the reduction of annual cost reduction and load lifetime increase.

  4. Investigating Friendship Quality: An Exploration of Self-Control and Social Control Theories' Friendship Hypotheses

    ERIC Educational Resources Information Center

    Boman, John H., IV; Krohn, Marvin D.; Gibson, Chris L.; Stogner, John M.

    2012-01-01

    While associations with deviant peers are well understood to impact individual development, less is understood about the relationship between friendship quality and delinquency. Two criminological theories--social control theory and self-control theory--are able to offer an explanation for the latter relationship. Social control and self-control…

  5. Dual-Process Theories of Higher Cognition: Advancing the Debate.

    PubMed

    Evans, Jonathan St B T; Stanovich, Keith E

    2013-05-01

    Dual-process and dual-system theories in both cognitive and social psychology have been subjected to a number of recently published criticisms. However, they have been attacked as a category, incorrectly assuming there is a generic version that applies to all. We identify and respond to 5 main lines of argument made by such critics. We agree that some of these arguments have force against some of the theories in the literature but believe them to be overstated. We argue that the dual-processing distinction is supported by much recent evidence in cognitive science. Our preferred theoretical approach is one in which rapid autonomous processes (Type 1) are assumed to yield default responses unless intervened on by distinctive higher order reasoning processes (Type 2). What defines the difference is that Type 2 processing supports hypothetical thinking and load heavily on working memory. PMID:26172965

  6. ADVANCED RADIATION THEORY SUPPORT ANNUAL REPORT 2002, FINAL REPORT

    SciTech Connect

    J. DAVIS; J. APRUZESE; , Y. CHONG; R. CLARK; A. DASGUPTA; J. GIULIANI; P. KEPPLE; R. TERRY; J. THORNHILL; A. VELIKOVICH

    2003-05-01

    Z-PINCH PHYSICS RADIATION FROM WIRE ARRAYS. This report describes the theory support of DTRA's Plasma Radiation Source (PRS) program carried out by NRL's Radiation Hydrodynamics Branch (Code 6720) in FY 2002. Included is work called for in DTRA MIPR 02-2045M - ''Plasma Radiation Theory Support'' and in DOE's Interagency Agreement DE-AI03-02SF22562 - ''Spectroscopic and Plasma Theory Support for Sandia National Laboratories High Energy Density Physics Campaign''. Some of this year's work was presented at the Dense Z-Pinches 5th International Conference held June 23-28 in Albuquerque, New Mexico. A common theme of many of these presentations was a demonstration of the importance of correctly treating the radiation physics for simulating Plasma Radiation Source (PRS) load behavior and diagnosing load properties, e.g, stagnation temperatures and densities. These presentations are published in the AIP Conference Proceedings and, for reference, they are included in Section 1 of this report. Rather than describe each of these papers in the Executive Summary, they refer to the abstracts that accompany each paper. As a testament to the level of involvement and expertise that the Branch brings to DTRA as well as the general Z-Pinch community, eight first-authored presentations were contributed at this conference as well as a Plenary and an Invited Talk. The remaining four sections of this report discuss subjects either not presented at the conference or requiring more space than allotted in the Proceedings.

  7. Human factors survey of advanced instrumentation and controls

    SciTech Connect

    Carter, R.J.

    1989-01-01

    A survey oriented towards identifying the human factors issues in regard to the use of advanced instrumentation and controls (I C) in the nuclear industry was conducted. A number of United States (US) and Canadian nuclear vendors and utilities were participants in the survey. Human factors items, subsumed under the categories of computer-generated displays (CGD), controls, organizational support, training, and related topics, were discussed. The survey found the industry to be concerned about the human factors issues related to the implementation of advanced I C. Fifteen potential human factors problems were identified. They include: the need for an advanced I C guideline equivalent to NUREG-0700; a role change in the control room from operator to supervisor; information overload; adequacy of existing training technology for advanced I C; and operator acceptance and trust. 11 refs., 1 tab.

  8. Advanced telerobotic control using neural networks

    NASA Technical Reports Server (NTRS)

    Pap, Robert M.; Atkins, Mark; Cox, Chadwick; Glover, Charles; Kissel, Ralph; Saeks, Richard

    1993-01-01

    Accurate Automation is designing and developing adaptive decentralized joint controllers using neural networks. We are then implementing these in hardware for the Marshall Space Flight Center PFMA as well as to be usable for the Remote Manipulator System (RMS) robot arm. Our design is being realized in hardware after completion of the software simulation. This is implemented using a Functional-Link neural network.

  9. Advancing a Technology of Self-Control.

    ERIC Educational Resources Information Center

    Martin, James E.; Mithaug, Dennis

    1986-01-01

    Examines self-control interventions considered effective in improving the performance of mentally retarded persons in acquiring, maintaining, and generalizing learned tasks. Studies employing self-monitoring, self-reinforcement, and antecedent cue regulation (self-instruction and picture cues) are cited. Picture cues are recommended as the most…

  10. Elements of an advanced integrated operator control station

    SciTech Connect

    Clarke, M.M.; Kreifeldt, J.G.

    1984-01-01

    One of the critical determinants of peformance for any remotely operated maintenance system is the compatibility achieved between elements of the man/machine interface (e.g., master manipulator controller, controls, displays, etc.) and the human operator. In the Remote Control Engineering task of the Consolidated Fuel Reprocessing Program, considerable attention has been devoted to optimizing the man/machine interface of the operator control station. This system must be considered an integral element of the overall maintenance work system which includes transporters, manipulators, remote viewing, and other parts. The control station must reflect the integration of the operator team, control/display panels, manipulator master controllers, and remote viewing monitors. Human factors principles and experimentation have been used in the development of an advanced integrated operator control station designed for the advance servomanipulator. Key features of this next-generation design are summarized in this presentation. 7 references, 4 figures.

  11. Elements of an advanced integrated operator control station

    SciTech Connect

    Clarke, M.M.; Kreifeldt, J.G.

    1984-01-01

    One of the critical determinants of performance for any remotely operated maintenance system is the compatibility achieved between elements of the man/machine interface (e.g., master manipulator controller, controls, displays) and the human operator. In the remote control engineering task of the Consolidated Fuel Reprocessing Program, considerable attention has been devoted to optimizing the man/machine interface of the operator control station. This system must be considered an integral element of the overall maintenance work system which includes transporters, manipulators, remote viewing, and other parts. The control station must reflect the integration of the operator team, control/display panels, manipulator master controllers, and remote viewing monitors. Human factors principles and experimentation have been used in the development of an advanced integrated operator control station designed for the advance servomanipulator. Key features of this next-generation design are summarized in this presentation. 7 references, 4 figures.

  12. Advanced concepts for controlling energy surety microgrids.

    SciTech Connect

    Menicucci, David F.; Ortiz-Moyet, Juan

    2011-05-01

    Today, researchers, engineers, and policy makers are seeking ways to meet the world's growing demand for energy while addressing critical issues such as energy security, reliability, and sustainability. Many believe that distributed generators operating within a microgrid have the potential to address most of these issues. Sandia National Laboratories has developed a concept called energy surety in which five of these 'surety elements' are simultaneously considered: energy security, reliability, sustainability, safety, and cost-effectiveness. The surety methodology leads to a new microgrid design that we call an energy surety microgrid (ESM). This paper discusses the unique control requirement needed to produce a microgrid system that has high levels of surety, describes the control system from the most fundamental level through a real-world example, and discusses our ideas and concepts for a complete system.

  13. OPTIMAL CONTROL THEORY FOR SUSTAINABLE ENVIRONMENTAL MANAGEMENT

    EPA Science Inventory

    Sustainable management of the human and natural systems, taking into account their interactions, has become paramount. To achieve this complex multidisciplinary objective, systems theory based techniques prove useful. The proposed work is a step in that direction. Taking a food w...

  14. Recent Advances of The Sh-theory of Avalanching Motions

    NASA Astrophysics Data System (ADS)

    Pudasaini, S. P.; Hutter, K.

    The Savage-Hutter (SH)-Theory of the gravity driven avalanching motion of a finite mass of cohesionless granular material has in 1989 been derived for 2D chute flows with free surface. Its physical basis is the density preserving fluid obeying Mohr- Coulomb internal friction and an equivalent law for basal sliding. The internal friction angle, , and the basal friction angle, , with are the only phenomenological coefficients of the model. The governing equations are formulated in a curvilinear co- ordinate system, and a von Karman-Polhausen procedure is used to deduce thickness ´ ´ averaged equations for the time and space evolution of the avalanche depth and the velocity profile. Extensions of the SH-theory to model 3D free surface flows subject to gravity have been derived for generalisations using an orthogonal metric in which the coordinate lines in the downhill direction are curved but not twisted. These formulations allow reproduction of the flow down a straight channel merging into a horizontal plane and yield a fair reproduction when being compared with laboratory experiments. We have recently derived model equations for a free gravity flow of granular mate- rials down a chute whose talweg follows a helical curve with constant pitch as well as channels generated by arbitrary space curves with slowly varying curvature and torsion. These are very important extensions to the original SH-theory. Two different metrics are used. For the first case we use a non-orthogonal and for the second an orthogonal metric. The depth averaged equations are deduced for both cases. Semi- analytical similarity solutions have been found to test the model equations. All equations derived from these extensions of the SH model are a hyperbolic system of PDEs with possibly discontinuous coefficients. Numerical integration schemes must be shock-capturing. We explain the integration procedure and shall present the results (provided the program works by the time of the conference).

  15. Advanced CIDI Emission Control System Development

    SciTech Connect

    Lambert, Christine

    2006-05-31

    Ford Motor Company, with ExxonMobil and FEV, participated in the Department of Energy's (DOE) Ultra-Clean Transportation Fuels Program with the goal to develop an innovative emission control system for light-duty diesel vehicles. The focus on diesel engine emissions was a direct result of the improved volumetric fuel economy (up to 50%) and lower CO2 emissions (up to 25%) over comparable gasoline engines shown in Europe. Selective Catalytic Reduction (SCR) with aqueous urea as the NOx reductant and a Catalyzed Diesel Particulate Filter (CDPF) were chosen as the primary emission control system components. The program expected to demonstrate more than 90% durable reduction in particulate matter (PM) and NOx emissions on a light-duty truck application, based on the FTP-75 drive cycle. Very low sulfur diesel fuel (<15 ppm-wt) enabled lower PM emissions, reduced fuel economy penalty due to the emission control system and improved long-term system durability. Significant progress was made toward a durable system to meet Tier 2 Bin 5 emission standards on a 6000 lbs light-duty truck. A 40% reduction in engine-out NOx emissions was achieved with a mid-size prototype diesel engine through engine recalibration and increased exhaust gas recirculation. Use of a rapid warm-up strategy and urea SCR provided over 90% further NOx reduction while the CDPF reduced tailpipe PM to gasoline vehicle levels. Development work was conducted to separately improve urea SCR and CDPF system durability, as well as improved oxidation catalyst function. Exhaust gas NOx and ammonia sensors were also developed further. While the final emission control system did not meet Tier 2 Bin 5 NOx after 120k mi of aging on the dynamometer, it did meet the standards for HC, NMOG, and PM, and an improved SCR catalyst was shown to have potential to meet the NOx standard, assuming the DOC durability could be improved further. Models of DOC and SCR function were developed to guide the study of several key design

  16. Advances on tensor network theory: symmetries, fermions, entanglement, and holography

    NASA Astrophysics Data System (ADS)

    Orús, Román

    2014-11-01

    This is a short review on selected theory developments on tensor network (TN) states for strongly correlated systems. Specifically, we briefly review the effect of symmetries in TN states, fermionic TNs, the calculation of entanglement Hamiltonians from projected entangled pair states (PEPS), and the relation between the multi-scale entanglement renormalization ansatz (MERA) and the AdS/CFT or gauge/gravity duality. We stress the role played by entanglement in the emergence of several physical properties and objects through the TN language. Some recent results along these lines are also discussed.

  17. Advances in time-dependent current-density functional theory

    NASA Astrophysics Data System (ADS)

    Berger, Arjan

    In this work we solve the problem of the gauge dependence of molecular magnetic properties (magnetizabilities, circular dichroism) using time-dependent current-density functional theory [1]. We also present a new functional that accurately describes the optical absorption spectra of insulators, semiconductors and metals [2] N. Raimbault, P.L. de Boeij, P. Romaniello, and J.A. Berger Phys. Rev. Lett. 114, 066404 (2015) J.A. Berger, Phys. Rev. Lett. 115, 137402 (2015) This study has been partially supported through the Grant NEXT No. ANR-10-LABX-0037 in the framework of the Programme des Investissements d'Avenir.

  18. Design of turbofan engine controls using output feedback regulator theory

    NASA Technical Reports Server (NTRS)

    Merrill, W. C.

    1977-01-01

    A multivariable control design procedure based on output feedback regulator (OFR) theory is applied to the F100 turbofan engine. Results for the OFR design are compared to a design based on linear quadratic regulator (LQR) theory. The OFR feedback control is designed in the full order state space and thus eliminates any need for model reduction techniques. Using the performance measure and control structure of the LQR design, an equivalent OFR feedback control is obtained. The flexibility of the OFR as a control design procedure is demonstrated, and differing feedback control structures are evaluated.

  19. Selected advanced aerodynamic and active control concepts development

    NASA Technical Reports Server (NTRS)

    1980-01-01

    A summary is presented of results obtained during analysis, design and test activities on six selected technical tasks directed at exploratory improvement of fuel efficiency for new and derivative transports. The work included investigations into the potential offered by natural laminar flow, improved surface coatings and advanced high lift concepts. Similar investigations covering optimum low-energy flight path control, integrated application of active controls and evaluation of primary flight control systems reliability and maintenance are also summarized. Recommendations are included for future work needed to exploit potential advancements.

  20. Sensors, controls, and man-machine interface for advanced teleoperation

    NASA Technical Reports Server (NTRS)

    Bejczy, A. K.

    1980-01-01

    Some advances are reviewed which have been made in teleoperator (i.e., mechanical activities performed by mechanical devices at a remote site under remote control) technology through introduction of sensors, computers, automation, and new man-machine interface devices and techniques for remote manipulator control. The state of the art is summarized and some basic problems and challenging developments are examined.

  1. Advanced Integrated Power and Attitude Control System (IPACS) study

    NASA Technical Reports Server (NTRS)

    Oglevie, R. E.; Eisenhaure, D. B.

    1985-01-01

    Integrated Power and Attitude Control System (IPACS) studies performed over a decade ago established the feasibility of simultaneously satisfying the demands of energy storage and attitude control through the use of rotating flywheels. It was demonstrated that, for a wide spectrum of applications, such a system possessed many advantages over contemporary energy storage and attitude control approaches. More recent technology advances in composite material rotors, magnetic suspension systems, and power control electronics have triggered new optimism regarding the applicability and merits of this concept. This study is undertaken to define an advanced IPACS and to evaluate its merits for a space station application. System and component designs are developed to establish the performance of this concept and system trade studies conducted to examine the viability of this approach relative to conventional candidate systems. It is clearly demonstrated that an advanced IPACS concept is not only feasible, but also offers substantial savings in mass and life-cycle cost for the space station mission.

  2. Photonics in advanced process control applications

    NASA Astrophysics Data System (ADS)

    Lundqvist, Stefan H.; Andersson, Torbjoern; Grimbrandt, Jan

    1999-02-01

    A measurement system optimized for process control in the industrial environment has been developed and successfully commercialized. The system comprises a central unit, which contains all sensitive electronic and electro-optic parts. Fiber optics is used to transport the probing laser light to the measuring points in the process. Extremely rugged sensor heads are used to interface to the harsh industrial environment. Adaptation to the different applications is solely made up by changing the type of sensor head used. Six different process control applications will be presented. Ammonia slip monitoring in the NO(subscript x4/ reduction process in power stations, waste incinerators and heavy-duty diesel engines. Measurement of water vapor and oxygen in municipal waste to energy plants. Monitoring of oxygen and the thermodynamic gas temperature in steel pellets manufacturing. Monitoring HF reduction in a dry scrubber and HF emission from a pot room. Experiences of CO emission peak monitoring to protect electro filter in a chemical waste incinerator. Finally, we will describe measurements of HCI in the raw gas to access the calorific value of waste and to optimize bag-house filter operation.

  3. Advanced Control Methodology for Biomass Combustion

    NASA Astrophysics Data System (ADS)

    Bjornsson, Stefan

    This thesis presents a feasibility study for a low cost sensor-based combustion control system using a predictive chemical kinetic model that captures efficiencies and pollution emissions during biomass combustion. Low cost sensor module was developed, the sensors were calibrated to measure carbon monoxide and particulate matter (PM) in combustion exhaust. Major combustion species in the exhaust of a commercial biomass furnace, operating with white oak, were measured. The species concentrations were measured using the low cost sensors and commercially available diagnostics. The low cost sensor outputs compare well with the reference instruments and the sensors can be employed to measure varying concentration of CO and particulate matter in combustion exhaust. A predictive chemical kinetic model was generated to simulate biomass processes. The model uses a four element chemical reactor network (CRN) and successfully simulates smoldering, ignition and flaming combustion events. The model agrees with concentration of CO and particulate matter from experiments. The sensors and CRN model can be integrated in a control system for biomass combustion that can potentially improve combustion efficiency and reduce emissions of particulate matter, CO and unburned hydrocarbons that have been linked to urban and rural air pollution resulting in adverse health effects.

  4. Advanced Controller for the Free-Piston Stirling Convertor

    NASA Technical Reports Server (NTRS)

    Gerber, Scott S.; Jamison, Mike; Roth, Mary Ellen; Regan, Timothy F.

    2004-01-01

    The free-piston Stirling power convertor is being considered as an advanced power conversion technology to be used for future NASA deep space missions requiring long life radioisotope power systems. This technology has a conversion efficiency of over 25%, which is significantly higher than the efficiency of the Radioisotope Thermal-electric Generators (RTG) now in use. The NASA Glenn Research Center has long been recognized as a leader in Stirling technology and is responsible for the development of advanced technologies that are intended to significantly improve key characteristics of the Stirling convertor. The advanced technologies identified for development also consider the requirements of potential future missions and the new capabilities that have become available in the associated technical areas. One of the key areas identified for technology development is the engine controller. To support this activity, an advanced controller is being developed for the Stirling power convertor. This controller utilizes active power factor correction electronics and microcontroller-based controls. The object of this paper is to present an overview of the advanced controller concept with modeling, simulation and hardware test data.

  5. Costs of children--benefit theory and population control.

    PubMed

    Tian, X

    1989-01-01

    In order to stem the rising fertility and growth rates in China, new theories and measures are needed. The author suggests new insights into the relationships between reproductive behavior and economic interests, regulation of individual reproductive behavior by such economic interests, and governmental performance with these interests in mind. Topics are devoted to the benefit theory about the costs of children, trends in Chinese children's costs and benefits, and family planning (FP) based on children's costs and benefits. Natural biological law governed people's reproductive behavior and the number of offspring until there was control over human reproduction. Factors which determine the desired number of children can be economic, cultural, political, historical, or geographical. In modern times and with the commercialism of society, children have been sometimes viewed as commodities and Western economists (Becker and Leibenstein) have theorized the cost benefit ratio to parents. Expected positive benefits are support, labor force contribution, and family happiness. Negative benefits are the direct and indirect costs in time and money raising children. Children are produced where benefits are positive, and where benefits and costs are equal, circumstances will determine the result. No children will be produced when costs exceed benefits. The concept of net costs is described. Chinese trends indicate a direction toward a market oriented economy. Instead of following Western theory, as economic development has advanced rapidly the value of children has grown. The reasons are explained as marginal children may still bring benefits in a market where the function of regulation of a labor market is limited, children still render better support for their parents without a developed social security system, and boys are expected to secure their families fortunes during the changing economic conditions. The author recognizes that other conditions such as the number of

  6. A task control theory of mirror-touch synesthesia.

    PubMed

    Heyes, Cecilia; Catmur, Caroline

    2015-01-01

    Ward and Banissy's illuminating discussion of mirror-touch synesthesia (MTS) encourages research testing two alternatives to Threshold Theory: Their own Self-Other Theory, and "Task Control Theory". MTS may be due to abnormal mirror activity plus a domain-general, rather than a specifically social, impairment in the ability to privilege processing of task-relevant over task-irrelevant information. PMID:26114543

  7. Utilizing Control Theory in Business Classrooms.

    ERIC Educational Resources Information Center

    Morrison, Pamela Porter

    1988-01-01

    In the formal school setting, the control of learning has typically been placed with the wrong person--the teacher. By modifying the control mechanism in the educational process and elevating the student to a position of "determining individual destiny," a catalyst for motivated learning may evolve. (JOW)

  8. A formal structure for advanced automatic flight-control systems

    NASA Technical Reports Server (NTRS)

    Meyer, G.; Cicolani, L. S.

    1975-01-01

    Techniques were developed for the unified design of multimode, variable authority automatic flight-control systems for powered-lift STOL and VTOL aircraft. A structure for such systems is developed to deal with the strong nonlinearities inherent in this class of aircraft, to admit automatic coupling with advanced air traffic control, and to admit a variety of active control tasks. The aircraft being considered is the augmentor wing jet STOL research aircraft.

  9. ADVANCED COMPRESSOR ENGINE CONTROLS TO ENHANCE OPERATION, RELIABILITY AND INTEGRITY

    SciTech Connect

    Gary D. Bourn; Jess W. Gingrich; Jack A. Smith

    2004-03-01

    This document is the final report for the ''Advanced Compressor Engine Controls to Enhance Operation, Reliability, and Integrity'' project. SwRI conducted this project for DOE in conjunction with Cooper Compression, under DOE contract number DE-FC26-03NT41859. This report addresses an investigation of engine controls for integral compressor engines and the development of control strategies that implement closed-loop NOX emissions feedback.

  10. Controlling adsorbate interactions for advanced chemical patterning

    NASA Astrophysics Data System (ADS)

    Saavedra Garcia, Hector M.

    Molecules designed to have specific interactions were used to influence the structural, physical, and chemical properties of self-assembled monolayers. In the case of 1-adamantanethiolate monolayers, the molecular structure influences lability, enabling alkanethiol molecules in solution to displace the 1-adamantanethiolate monolayers, ultimately leading to complete molecular exchange. The similar Au-S bond environments measured for both n-alkanethiolate and 1-adamantanethiolate monolayers indicate that displacement is not a result of weakened Au-S bonds. Instead, it was hypothesized that the density differences in the two monolayers provide a substantial enthalpic driver, aided by differences in van der Waals forces, ultimately leading to complete displacement of the 1-adamantenthiol molecules. Additionally, it was discovered that displacement occurs via fast insertion of n-dodecanethiolate at the defects in the original 1-adamantanethiolate monolayer, which nucleates an island growth phase and is followed by slow ordering of the n-dodecanethiolate domains into a denser and more crystalline form. Langmuir-based kinetics, which describe alkanethiolate adsorption on bare Au{111}, fail to model this displacement reaction. Instead, a model of perimeter-dependent island growth yields good agreement with kinetic data over a 100-fold variation in n-dodecanethiol concentration. Rescaling the growth rate at each concentration collapses all the data onto a single universal curve, suggesting that displacement is a scale-free process. Exploiting the knowledge gained by studying 1-adamantethiolate monolayer displacement, a reversible molecular resist was developed, in which displacement is controlled via external stimuli. This methodology for the fabrication of controllably displaceable monolayers relies on carboxyl-functionalized self-assembled monolayers and in-situ Fischer esterification. Using an 11-mercaptoundecanoic acid monolayer as a model system, it was shown that in

  11. Advances in random matrix theory, zeta functions, and sphere packing.

    PubMed

    Hales, T C; Sarnak, P; Pugh, M C

    2000-11-21

    Over four hundred years ago, Sir Walter Raleigh asked his mathematical assistant to find formulas for the number of cannonballs in regularly stacked piles. These investigations aroused the curiosity of the astronomer Johannes Kepler and led to a problem that has gone centuries without a solution: why is the familiar cannonball stack the most efficient arrangement possible? Here we discuss the solution that Hales found in 1998. Almost every part of the 282-page proof relies on long computer verifications. Random matrix theory was developed by physicists to describe the spectra of complex nuclei. In particular, the statistical fluctuations of the eigenvalues ("the energy levels") follow certain universal laws based on symmetry types. We describe these and then discuss the remarkable appearance of these laws for zeros of the Riemann zeta function (which is the generating function for prime numbers and is the last special function from the last century that is not understood today.) Explaining this phenomenon is a central problem. These topics are distinct, so we present them separately with their own introductory remarks. PMID:11058156

  12. Computing aerodynamic sound using advanced statistical turbulence theories

    NASA Technical Reports Server (NTRS)

    Hecht, A. M.; Teske, M. E.; Bilanin, A. J.

    1981-01-01

    It is noted that the calculation of turbulence-generated aerodynamic sound requires knowledge of the spatial and temporal variation of Q sub ij (xi sub k, tau), the two-point, two-time turbulent velocity correlations. A technique is presented to obtain an approximate form of these correlations based on closure of the Reynolds stress equations by modeling of higher order terms. The governing equations for Q sub ij are first developed for a general flow. The case of homogeneous, stationary turbulence in a unidirectional constant shear mean flow is then assumed. The required closure form for Q sub ij is selected which is capable of qualitatively reproducing experimentally observed behavior. This form contains separation time dependent scale factors as parameters and depends explicitly on spatial separation. The approximate forms of Q sub ij are used in the differential equations and integral moments are taken over the spatial domain. The velocity correlations are used in the Lighthill theory of aerodynamic sound by assuming normal joint probability.

  13. Advances in random matrix theory, zeta functions, and sphere packing

    PubMed Central

    Hales, T. C.; Sarnak, P.; Pugh, M. C.

    2000-01-01

    Over four hundred years ago, Sir Walter Raleigh asked his mathematical assistant to find formulas for the number of cannonballs in regularly stacked piles. These investigations aroused the curiosity of the astronomer Johannes Kepler and led to a problem that has gone centuries without a solution: why is the familiar cannonball stack the most efficient arrangement possible? Here we discuss the solution that Hales found in 1998. Almost every part of the 282-page proof relies on long computer verifications. Random matrix theory was developed by physicists to describe the spectra of complex nuclei. In particular, the statistical fluctuations of the eigenvalues (“the energy levels”) follow certain universal laws based on symmetry types. We describe these and then discuss the remarkable appearance of these laws for zeros of the Riemann zeta function (which is the generating function for prime numbers and is the last special function from the last century that is not understood today.) Explaining this phenomenon is a central problem. These topics are distinct, so we present them separately with their own introductory remarks. PMID:11058156

  14. Advances in electron kinetics and theory of gas discharges

    SciTech Connect

    Kolobov, Vladimir I.

    2013-10-15

    “Electrons, like people, are fertile and infertile: high-energy electrons are fertile and able to reproduce.”—Lev TsendinModern physics of gas discharges increasingly uses physical kinetics for analysis of non-equilibrium plasmas. The description of underlying physics at the kinetic level appears to be important for plasma applications in modern technologies. In this paper, we attempt to grasp the legacy of Professor Lev Tsendin, who advocated the use of the kinetic approach for understanding fundamental problems of gas discharges. We outline the fundamentals of electron kinetics in low-temperature plasmas, describe elements of the modern kinetic theory of gas discharges, and show examples of the theoretical approach to gas discharge problems used by Lev Tsendin. Important connections between electron kinetics in gas discharges and semiconductors are also discussed. Using several examples, we illustrate how Tsendin's ideas and methods are currently being developed for the implementation of next generation computational tools for adaptive kinetic-fluid simulations of gas discharges used in modern technologies.

  15. The Application of Layer Theory to Design: The Control Layer

    ERIC Educational Resources Information Center

    Gibbons, Andrew S.; Langton, Matthew B.

    2016-01-01

    A theory of design layers proposed by Gibbons ("An Architectural Approach to Instructional Design." Routledge, New York, 2014) asserts that each layer of an instructional design is related to a body of theory closely associated with the concerns of that particular layer. This study focuses on one layer, the control layer, examining…

  16. Design of flight control systems via robust decoupled servomechanism theory

    NASA Technical Reports Server (NTRS)

    Wang, S.-H.; Davison, E. J.

    1979-01-01

    Decoupling theory and robust servomechanism theory are applied to the design of linear multivariable systems with large parameter variations. In addition to being approximately decoupled in the transient period, the over-all system achieves tracking and disturbance rejection robustly in the steady state. An example in flight control system is given.

  17. Client-Controlled Case Information: A General System Theory Perspective

    ERIC Educational Resources Information Center

    Fitch, Dale

    2004-01-01

    The author proposes a model for client control of case information via the World Wide Web built on principles of general system theory. It incorporates the client into the design, resulting in an information structure that differs from traditional human services information-sharing practices. Referencing general system theory, the concepts of…

  18. Relationships between digital signal processing and control and estimation theory

    NASA Technical Reports Server (NTRS)

    Willsky, A. S.

    1978-01-01

    Research areas associated with digital signal processing and control and estimation theory are identified. Particular attention is given to image processing, system identification problems (parameter identification, linear prediction, least squares, Kalman filtering), stability analyses (the use of the Liapunov theory, frequency domain criteria, passivity), and multiparameter systems, distributed processes, and random fields.

  19. Advances in far-field holography - Theory and applications

    NASA Astrophysics Data System (ADS)

    Thompson, B. J.; Dunn, P.

    1980-05-01

    The development status of far-field holography is reviewed, with emphasis on such applications of single and multiple pulse methods as agricultural pest control, cavitation studies, and the evaluation of fuel droplet size and burning in engines. It is shown that resolution remains a major consideration and noise a major limiting factor, with parameters such as film resolution, format and processing, and spatial and temporal coherence meriting further consideration.

  20. Advanced robust tracking control of a powered wheelchair system.

    PubMed

    Nguyen, Nghia T; Nguyen, Hung T; Su, Steven

    2007-01-01

    In this paper, the dynamic multivariable model of the wheelchair system is obtained including the presence of transportation lags. The triangular diagonal dominance (TDD) decoupling technique is applied to reduce this multivariable control problem into two independent scalar control problems. An advanced robust control technique for the wheelchair has been developed based on the combination of a TDD decoupling strategy and neural network controller design. The results obtained from the real-time implementation confirm that robust performance for this multivariable wheelchair control system can indeed be achieved. PMID:18003071

  1. Multivariable quadratic synthesis of an advanced turbofan engine controller

    NASA Technical Reports Server (NTRS)

    Dehoff, R. L.; Hall, W. E., Jr.

    1978-01-01

    A digital controller for an advanced turbofan engine utilizing multivariate feedback is described. The theoretical background of locally linearized control synthesis is reviewed briefly. The application of linear quadratic regulator techniques to the practical control problem is presented. The design procedure has been applied to the F100 turbofan engine, and details of the structure of this system are explained. Selected results from simulations of the engine and controller are utilized to illustrate the operation of the system. It is shown that the general multivariable design procedure will produce practical and implementable controllers for modern, high-performance turbine engines.

  2. Some Contributions of General Systems Theory, Cybernetics Theory and Management Control Theory to Evaluation Theory and Practice. Research on Evaluation Program Paper and Report Series. Interim Draft.

    ERIC Educational Resources Information Center

    Cook, Desmond L.

    This document, one of a series of reports examining the possible contribution of other disciplines to evaluation methodology, describes the major elements of general systems theory (GST), cybernetics theory (CT) and management control theory (MCT). The author suggests that MCT encapsulates major concerns of evaluation since it reveals that…

  3. Near minimum-time maneuvers of the advanced space structures technology research experiment (ASTREX) test article: Theory and experiments

    NASA Technical Reports Server (NTRS)

    Vadali, Srinivas R.; Carter, Michael T.

    1994-01-01

    The Phillips Laboratory at the Edwards Air Force Base has developed the Advanced Space Structures Technology Research Experiment (ASTREX) facility to serve as a testbed for demonstrating the applicability of proven theories to the challenges of spacecraft maneuvers and structural control. This report describes the work performed on the ASTREX test article by Texas A&M University under contract NAS119373 as a part of the Control-Structure Interaction (CSI) Guest Investigator Program. The focus of this work is on maneuvering the ASTREX test article with compressed air thrusters that can be throttled, while attenuating structural excitation. The theoretical foundation for designing the near minimum-time thrust commands is based on the generation of smooth, parameterized optimal open-loop control profiles, and the determination of control laws for final position regulation and tracking using Lyapunov stability theory. Details of the theory, mathematical modeling, model updating, and compensation for the presence of 'real world' effects are described and the experimental results are presented. The results show an excellent match between theory and experiments.

  4. Minimum Control Requirements for Advanced Life Support Systems

    NASA Technical Reports Server (NTRS)

    Boulange, Richard; Jones, Harry; Jones, Harry

    2002-01-01

    Advanced control technologies are not necessary for the safe, reliable and continuous operation of Advanced Life Support (ALS) systems. ALS systems can and are adequately controlled by simple, reliable, low-level methodologies and algorithms. The automation provided by advanced control technologies is claimed to decrease system mass and necessary crew time by reducing buffer size and minimizing crew involvement. In truth, these approaches increase control system complexity without clearly demonstrating an increase in reliability across the ALS system. Unless these systems are as reliable as the hardware they control, there is no savings to be had. A baseline ALS system is presented with the minimal control system required for its continuous safe reliable operation. This baseline control system uses simple algorithms and scheduling methodologies and relies on human intervention only in the event of failure of the redundant backup equipment. This ALS system architecture is designed for reliable operation, with minimal components and minimal control system complexity. The fundamental design precept followed is "If it isn't there, it can't fail".

  5. Application of stability theory to laminar flow control

    NASA Technical Reports Server (NTRS)

    Hefner, J. N.; Bushnell, D. M.

    1979-01-01

    The paper summarizes the state-of-the-art for application of stability theory to laminar flow control using suction, wall temperature and/or favorable pressure gradient ('natural laminar flow'). Discussions include current LFC problem areas requiring stability analyses, methods of relating stability theory to transition with results from data and theory comparisons available thus far, and a summary of low disturbance data available for theory calibration on swept wings. Critical issues highlighted are problems peculiar to suction LFC on high performance transonic wings and application of the e-to-the-n-power method to both low and high speed flight data.

  6. Lie theory and control systems defined on spheres

    NASA Technical Reports Server (NTRS)

    Brockett, R. W.

    1972-01-01

    It is shown that in constructing a theory for the most elementary class of control problems defined on spheres, some results from the Lie theory play a natural role. To understand controllability, optimal control, and certain properties of stochastic equations, Lie theoretic ideas are needed. The framework considered here is the most natural departure from the usual linear system/vector space problems which have dominated control systems literature. For this reason results are compared with those previously available for the finite dimensional vector space case.

  7. Comparison of Advanced Distillation Control Methods, Final Technical Report

    SciTech Connect

    Dr. James B. Riggs

    2000-11-30

    Detailed dynamic simulations of three industrial distillation columns (a propylene/propane splitter, a xylene/toluene column, and a depropanizer) have been used to evaluate configuration selections for single-ended and dual-composition control, as well as to compare conventional and advanced control approaches. In addition, a simulator of a main fractionator was used to compare the control performance of conventional and advanced control. For each case considered, the controllers were tuned by using setpoint changes and tested using feed composition upsets. Proportional Integral (PI) control performance was used to evaluate the configuration selection problem. For single ended control, the energy balance configuration was found to yield the best performance. For dual composition control, nine configurations were considered. It was determined that the use of dynamic simulations is required in order to identify the optimum configuration from among the nine possible choices. The optimum configurations were used to evaluate the relative control performance of conventional PI controllers, MPC (Model Predictive Control), PMBC (Process Model-Based Control), and ANN (Artificial Neural Networks) control. It was determined that MPC works best when one product is much more important than the other, while PI was superior when both products were equally important. PMBC and ANN were not found to offer significant advantages over PI and MPC. MPC was found to outperform conventional PI control for the main fractionator. MPC was applied to three industrial columns: one at Phillips Petroleum and two at Union Carbide. In each case, MPC was found to significantly outperform PI controls. The major advantage of the MPC controller is its ability to effectively handle a complex set of constraints and control objectives.

  8. Motor control theories and their applications.

    PubMed

    Latash, Mark L; Levin, Mindy F; Scholz, John P; Schöner, Gregor

    2010-01-01

    We describe several influential hypotheses in the field of motor control including the equilibrium-point (referent configuration) hypothesis, the uncontrolled manifold hypothesis, and the idea of synergies based on the principle of motor abundance. The equilibrium-point hypothesis is based on the idea of control with thresholds for activation of neuronal pools; it provides a framework for analysis of both voluntary and involuntary movements. In particular, control of a single muscle can be adequately described with changes in the threshold of motor unit recruitment during slow muscle stretch (threshold of the tonic stretch reflex). Unlike the ideas of internal models, the equilibrium-point hypothesis does not assume neural computations of mechanical variables. The uncontrolled manifold hypothesis is based on the dynamic system approach to movements; it offers a toolbox to analyze synergic changes within redundant sets of elements related to stabilization of potentially important performance variables. The referent configuration hypothesis and the principle of abundance can be naturally combined into a single coherent scheme of control of multi-element systems. A body of experimental data on healthy persons and patients with movement disorders are reviewed in support of the mentioned hypotheses. In particular, movement disorders associated with spasticity are considered as consequences of an impaired ability to shift threshold of the tonic stretch reflex within the whole normal range. Technical details and applications of the mentioned hypo-theses to studies of motor learning are described. We view the mentioned hypotheses as the most promising ones in the field of motor control, based on a solid physical and neurophysiological foundation. PMID:20944446

  9. Advanced helicopter cockpit and control configurations for helicopter combat missions

    NASA Technical Reports Server (NTRS)

    Haworth, Loran A.; Atencio, Adolph, Jr.; Bivens, Courtland; Shively, Robert; Delgado, Daniel

    1987-01-01

    Two piloted simulations were conducted by the U.S. Army Aeroflightdynamics Directorate to evaluate workload and helicopter-handling qualities requirements for single pilot operation in a combat Nap-of-the-Earth environment. The single-pilot advanced cockpit engineering simulation (SPACES) investigations were performed on the NASA Ames Vertical Motion Simulator, using the Advanced Digital Optical Control System control laws and an advanced concepts glass cockpit. The first simulation (SPACES I) compared single pilot to dual crewmember operation for the same flight tasks to determine differences between dual and single ratings, and to discover which control laws enabled adequate single-pilot helicopter operation. The SPACES II simulation concentrated on single-pilot operations and use of control laws thought to be viable candidates for single pilot operations workload. Measures detected significant differences between single-pilot task segments. Control system configurations were task dependent, demonstrating a need for inflight reconfigurable control system to match the optimal control system with the required task.

  10. Overview of the US program of controls for advanced reactors

    SciTech Connect

    White, J.D.; Sackett, J.I.; Monson, R.; Lindsay, R.W.; Carroll, D.G.

    1989-01-01

    An automated control system can incorporate control goals and strategies, assessment of present and future plant status, diagnostic evaluation and maintenance planning, and signal and command validation. It has not been feasible to employ these capabilities in conventional hard-wired, analog, control systems. Recent advances in computer-based digital data acquisition systems, process controllers, fiber-optic signal transmission artificial intelligence tools and methods, and small inexpensive, fast, large-capacity computers---with both numeric and symbolic capabilities---have provided many of the necessary ingredients for developing large, practical automated control systems. Furthermore, recent reactor designs which provide strong passive responses to operational upsets or accidents afford good opportunities to apply these advances in control technology. This paper presents an overall US national perspective for advanced controls research and development. The goals of high reliability, low operating cost and simple operation are described. The staged approach from conceptualization through implementation is discussed. Then the paper describes the work being done by ORNL, ANL and GE. The relationship of this work to the US commercial industry is also discussed.

  11. Design of turbofan engine controls using output feedback regulator theory

    NASA Technical Reports Server (NTRS)

    Merrill, W. C.

    1977-01-01

    A multivariable control design procedure based on output feedback regulator (OFR) theory is applied to the F100 turbofan engine. Results for the OFR design are compared to a design based on linear quadratic regulator (LQR) theory. This LQR design was obtained as part of the F100 Multivariable Control Synthesis (MVCS) program. In the MVCS program the LQR feedback control was designed in a reduced dimension state space and then applied to the original system. However, the OFR feedback control is designed in the full order state space and thus eliminates any need for model reduction techniques. Using the performance measure and control structure of the MVCS program LQR design, an equivalent OFR feedback control is obtained. The flexibility of the OFR as a control design procedure is demonstrated and differing feedback control structures are evaluated.

  12. Vision Based Autonomous Robotic Control for Advanced Inspection and Repair

    NASA Technical Reports Server (NTRS)

    Wehner, Walter S.

    2014-01-01

    The advanced inspection system is an autonomous control and analysis system that improves the inspection and remediation operations for ground and surface systems. It uses optical imaging technology with intelligent computer vision algorithms to analyze physical features of the real-world environment to make decisions and learn from experience. The advanced inspection system plans to control a robotic manipulator arm, an unmanned ground vehicle and cameras remotely, automatically and autonomously. There are many computer vision, image processing and machine learning techniques available as open source for using vision as a sensory feedback in decision-making and autonomous robotic movement. My responsibilities for the advanced inspection system are to create a software architecture that integrates and provides a framework for all the different subsystem components; identify open-source algorithms and techniques; and integrate robot hardware.

  13. Advanced software design and standards for traffic signal control

    SciTech Connect

    Bullock, D.; Hendrickson, C. )

    1992-05-01

    Improves traffic management and control systems are widely reported to be cost-effective investments. Simply retiming signals can provide significant benefits by reducing vehicle stops, travel times, and fuel consumption. The installation of advanced traffic management systems (ATMS) can provide even greater savings. However, many hardware and software obstacles have impeded the actual implementation of advanced traffic management systems. The general hardware and software limitations of current traffic signal control technology are reviewed in this paper. The impact of these deficiencies is discussed in the context of three example applications. Based on this discussion, the paper identifies several computing issues that should be addressed in order to reduce the effort involved with integrating existing traffic control devices. Adoption of standard industrial control computing platforms and development of new communication and software engineering models are recommendrecommended.

  14. Optical metrology for advanced process control: full module metrology solutions

    NASA Astrophysics Data System (ADS)

    Bozdog, Cornel; Turovets, Igor

    2016-03-01

    Optical metrology is the workhorse metrology in manufacturing and key enabler to patterning process control. Recent advances in device architecture are gradually shifting the need for process control from the lithography module to other patterning processes (etch, trim, clean, LER/LWR treatments, etc..). Complex multi-patterning integration solutions, where the final pattern is the result of multiple process steps require a step-by-step holistic process control and a uniformly accurate holistic metrology solution for pattern transfer for the entire module. For effective process control, more process "knobs" are needed, and a tighter integration of metrology with process architecture.

  15. Status report on the Advanced Light Source control system, 1993

    SciTech Connect

    Young, J.; Brown, W. Jr.; Cork, C.

    1993-10-01

    The Advanced Light Source (ALS), under construction for the past seven years, has become operational. The accelerator has been successfully commissioned using a control system based on hundreds of controllers of our own design and high performance personal computers which are the operator interface. The first beamlines are being commissioned using a control system based on VME hardware and the Experimental Physics and Industrial Control System (EPICS) software. The two systems are being integrated, and this paper reports on the current work being done.

  16. Lagrange duality theory for convex control problems

    NASA Technical Reports Server (NTRS)

    Hager, W. W.; Mitter, S. K.

    1976-01-01

    The Lagrange dual to a control problem is studied. The principal result based on the Hahn-Banach theorem proves that the dual problem has an optimal solution if there exists an interior point for the constraint set. A complementary slackness condition holds, if the primal problem has an optimal solution. A necessary and sufficient condition for the optimality of solutions to the primal and the dual problem is also presented.

  17. Advanced reactor instrumentation and control reliability and risk assessment

    SciTech Connect

    Fullwood, R.; Gunther, W.; Valente, J.; Azarm, M.A.

    1991-01-01

    Advanced nuclear power reactors will used different approaches to achieving a higher level of safety than the first generation. One approach used the technological developments in computation and electronics in the form of digital instrumentation and control (I C) to enhance the reliability, and accuracy of information for plant control, responding to the information, and controlling the plant and its systems under normal and upset environments in various states of degradation. Evaluating the reliability and safety of advanced I C systems requires determining the reliability of the I C used in the advanced reactors which involves distributed processing, data pile-up, interactive systems, the man-machine interface, various forms of automatic control, and systems interactions. From these analyses will come an understanding of the potential of the new I C, and protection from its vulnerabilities to enhance the safe operation of the new plants. Technological, safety, reliability, and regulatory issues associated with advanced I C for the new reactors are discussed herein. The issues are presented followed by suggested approaches to their resolution.

  18. Advanced reactor instrumentation and control reliability and risk assessment

    SciTech Connect

    Fullwood, R.; Gunther, W.; Valente, J.; Azarm, M.A.

    1991-12-31

    Advanced nuclear power reactors will used different approaches to achieving a higher level of safety than the first generation. One approach used the technological developments in computation and electronics in the form of digital instrumentation and control (I&C) to enhance the reliability, and accuracy of information for plant control, responding to the information, and controlling the plant and its systems under normal and upset environments in various states of degradation. Evaluating the reliability and safety of advanced I&C systems requires determining the reliability of the I&C used in the advanced reactors which involves distributed processing, data pile-up, interactive systems, the man-machine interface, various forms of automatic control, and systems interactions. From these analyses will come an understanding of the potential of the new I&C, and protection from its vulnerabilities to enhance the safe operation of the new plants. Technological, safety, reliability, and regulatory issues associated with advanced I&C for the new reactors are discussed herein. The issues are presented followed by suggested approaches to their resolution.

  19. Advanced control for airbreathing engines, volume 1: Pratt and Whitney

    NASA Technical Reports Server (NTRS)

    Ralph, J. A.

    1993-01-01

    The application of advanced control concepts to air breathing engines may yield significant improvements in aircraft/engine performance and operability. Screening studies of advanced control concepts for air breathing engines were conducted by three major domestic aircraft engine manufacturers to determine the potential impact of concepts on turbine engine performance and operability. The purpose of the studies was to identify concepts which offered high potential yet may incur high research and development risk. A target suite of proposed advanced control concepts was formulated and evaluated in a two phase study to quantify each concept's impact on desired engine characteristics. To aid in the evaluation specific aircraft/engine combinations were considered: a Military High Performance Fighter mission, a High Speed Civil Transport mission, and a Civil Tiltrotor mission. Each of the advanced control concepts considered in the study are defined and described. The concept potential impact on engine performance was determined. Relevant figures of merit on which to evaluate the concepts are determined. Finally, the concepts are ranked with respect to the target aircraft/engine missions. A final report describing the screening studies was prepared by each engine manufacturer. Volume 1 of these reports describes the studies performed by Pratt & Whitney.

  20. Advanced controls for airbreathing engines, volume 3: Allison gas turbine

    NASA Technical Reports Server (NTRS)

    Bough, R. M.

    1993-01-01

    The application of advanced control concepts to airbreathing engines may yield significant improvements in aircraft/engine performance and operability. Screening studies of advanced control concepts for airbreathing engines were conducted by three major domestic aircraft engine manufacturers to determine the potential impact of concepts on turbine engine performance and operability. The purpose of the studies was to identify concepts which offered high potential yet may incur high research and development risk. A target suite of proposed advanced control concepts was formulated and evaluated in a two-phase study to quantify each concept's impact on desired engine characteristics. To aid in the evaluation specific aircraft/engine combinations were considered: a Military High Performance Fighter mission, a High Speed Civil Transport mission, and a Civil Tiltrotor mission. Each of the advanced control concepts considered in the study are defined and described. The concept potential impact on engine performance was determined. Relevant figures of merit on which to evaluate the concepts are determined. Finally, the concepts are ranked with respect to the target aircraft/engine missions. A final report describing the screening studies was prepared by each engine manufacturer. Volume 3 of these reports describes the studies performed by the Allison Gas Turbine Division.

  1. The implementation and control of advanced manufacturing systems

    NASA Astrophysics Data System (ADS)

    Anstiss, P.

    An account is given of the development and control of a flexible manufacturing system for small machined parts which can prepare raw materials for fixturing, assemble all necessary resources, then process 'nests' of components through machining, inspection, and secondary operations to produce finished parts ready for surface treatment or painting. The system employs automated stores, transport and machine tools, local area network communications, advanced computer control systems for all automatic and manual functions, and comprehensive tool storage, handling and preparation facilities.

  2. Access control and interlock system at the Advanced Photon Source

    SciTech Connect

    Forrestal, J.; Hogrefe, R.; Knott, M.; McDowell, W.; Reigle, D.; Solita, L.; Koldenhoven, R.; Haid, D.

    1997-08-01

    The Advanced Photon Source (APS) consists of a linac, position accumulator ring (PAR), booster synchrotron, storage ring, and up to 70 experimental beamlines. The Access Control and Interlock System (ACIS) utilizes redundant programmable logic controllers (PLCs) and a third hard-wired chain to protect personnel from prompt radiation generated by the linac, PAR, synchrotron, and storage ring. This paper describes the ACIS`s design philosophy, configuration, hardware, functionality, validation requirements, and operational experience.

  3. A Clinical Assessment Tool for Advanced Theory of Mind Performance in 5 to 12 Year Olds

    ERIC Educational Resources Information Center

    O'Hare, Anne E.; Bremner, Lynne; Nash, Marysia; Happe, Francesca; Pettigrew, Luisa M.

    2009-01-01

    One hundred forty typically developing 5- to 12-year-old children were assessed with a test of advanced theory of mind employing Happe's strange stories. There was no significant difference in performance between boys and girls. The stories discriminated performance across the different ages with the lowest performance being in the younger…

  4. Advances in the theory of 0{nu}{beta}{beta} decay

    SciTech Connect

    Iachello, F.; Kotila, J.; Barea, J.

    2011-12-16

    Recent advances in the theory of 0{nu}{beta}{beta} decay are briefly discussed. A complete list of nuclear matrix elements within the framework of the Interacting Boson Model (IBM-2) is given. Results of a novel calculation of phase space factors with exact Dirac wave functions and electron screening are also presented.

  5. The Transformation of Learning: Advances in Cultural-Historical Activity Theory

    ERIC Educational Resources Information Center

    van Oers, Bert, Ed.; Wardekker, Wim, Ed.; Elbers, Ed, Ed.; van der Veer, Rene, Ed.

    2010-01-01

    Learning is a changing phenomenon, depending on the advances in theory and research. This book presents a relatively new approach to learning, based on meaningful human activities in cultural practices and in collaboration with others. It draws extensively from the ideas of Lev Vygotsky and his recent followers. The book presents ideas that…

  6. Meeting Students Where They Are: Advancing a Theory and Practice of Archives in the Classroom

    ERIC Educational Resources Information Center

    Saidy, Christina; Hannah, Mark; Sura, Tom

    2011-01-01

    This article uses theories of technical communication and archives to advance a pedagogy that includes archival production in the technical communication classroom. By developing and maintaining local classroom archives, students directly engage in valuable processes of appraisal, selection, collaboration, and retention. The anticipated outcomes…

  7. Melodic Dictation Instruction: A Survey of Advanced Placement Music Theory Teachers

    ERIC Educational Resources Information Center

    Buonviri, Nathan O.; Paney, Andrew S.

    2015-01-01

    Based on relevant literature and recent qualitative findings, the purpose of this survey research was to identify pedagogical approaches to melodic dictation employed by Advanced Placement (AP) Music Theory teachers across the United States. The researcher-designed survey questions focused on pitch and rhythm skills, instructional resources,…

  8. Advancing Sexuality Studies: A Short Course on Sexuality Theory and Research Methodologies

    ERIC Educational Resources Information Center

    Fletcher, Gillian; Dowsett, Gary W.; Duncan, Duane; Slavin, Sean; Corboz, Julienne

    2013-01-01

    Critical Sexuality Studies is an emerging field of academic enquiry linked to an international network of advocacy agencies, activists, and political issues. This paper reports on the development of an advanced short course in sexuality theory and research, drawing on Critical Sexuality Studies and aiming directly at academics in developing…

  9. An Investigation of the Advance Organizer Theory as an Effective Teaching Model.

    ERIC Educational Resources Information Center

    Downing, Agnes

    This paper advocates for the improvement of presentational methods of teaching and expository learning, based on David Ausubel's theory of Meaningful Verbal Learning and its derivative, the Advance Organizer Model of Teaching. This approach to teaching enables teachers to convey large amounts of information as meaningfully and efficiently as…

  10. Supervisory Control System Architecture for Advanced Small Modular Reactors

    SciTech Connect

    Cetiner, Sacit M; Cole, Daniel L; Fugate, David L; Kisner, Roger A; Melin, Alexander M; Muhlheim, Michael David; Rao, Nageswara S; Wood, Richard Thomas

    2013-08-01

    This technical report was generated as a product of the Supervisory Control for Multi-Modular SMR Plants project within the Instrumentation, Control and Human-Machine Interface technology area under the Advanced Small Modular Reactor (SMR) Research and Development Program of the U.S. Department of Energy. The report documents the definition of strategies, functional elements, and the structural architecture of a supervisory control system for multi-modular advanced SMR (AdvSMR) plants. This research activity advances the state-of-the art by incorporating decision making into the supervisory control system architectural layers through the introduction of a tiered-plant system approach. The report provides a brief history of hierarchical functional architectures and the current state-of-the-art, describes a reference AdvSMR to show the dependencies between systems, presents a hierarchical structure for supervisory control, indicates the importance of understanding trip setpoints, applies a new theoretic approach for comparing architectures, identifies cyber security controls that should be addressed early in system design, and describes ongoing work to develop system requirements and hardware/software configurations.

  11. Helicopter trajectory planning using optimal control theory

    NASA Technical Reports Server (NTRS)

    Menon, P. K. A.; Cheng, V. H. L.; Kim, E.

    1988-01-01

    A methodology for optimal trajectory planning, useful in the nap-of-the-earth guidance of helicopters, is presented. This approach uses an adjoint-control transformation along with a one-dimensional search scheme for generating the optimal trajectories. In addition to being useful for helicopter nap-of-the-earth guidance, the trajectory planning solution is of interest in several other contexts, such as robotic vehicle guidance and terrain-following guidance for cruise missiles and aircraft. A distinguishing feature of the present research is that the terrain constraint and the threat envelopes are incorporated in the equations of motion. Second-order necessary conditions are examined.

  12. Economic convergence of environmental control and advanced technology

    SciTech Connect

    Bolli, R.E.; Haslbeck, J.L.

    1995-12-31

    Emerging advanced technologies for environmental control have many advantages over conventional, single pollutant removal processes. Features include high efficiencies, multiple pollutant control and zero waste streams. In the past, the economics for state-of-the-art emission control processes could not compete with proven, low-efficiency scrubbers that create throw away by-products. With the implementation of the Clean Air Act Amendments (CAAA), the entire economic environment has changed. If a single process can provide a facility`s compliance requirements for Title I, Title III and Title IV of the CAAA, its net costs can be lower than conventional technology and actually provide economic incentives for overcontrol. The emission allowance program is maturing and the annual revenues from overcontrol of SO{sub 2} are easily quantified. The economics of NO{sub x} control and offsets are currently being realized as EPA identified Title IV requirements, and facilities begin to realize the impact from Title I NO{sub x} control. Air toxic control from Title III could require yet a third control process for a facility to maintain emission compliance. The costs associated with single control strategies vs. multiple pollutant control processes will be discussed and compared. This paper will also present a specific application of the NOXSO Process and identify the potential advantages that can transform advanced technologies, like NOXSO, into the prudent solution for overall environmental compliance.

  13. Controlling death: the false promise of advance directives.

    PubMed

    Perkins, Henry S

    2007-07-01

    Advance directives promise patients a say in their future care but actually have had little effect. Many experts blame problems with completion and implementation, but the advance directive concept itself may be fundamentally flawed. Advance directives simply presuppose more control over future care than is realistic. Medical crises cannot be predicted in detail, making most prior instructions difficult to adapt, irrelevant, or even misleading. Furthermore, many proxies either do not know patients' wishes or do not pursue those wishes effectively. Thus, unexpected problems arise often to defeat advance directives, as the case in this paper illustrates. Because advance directives offer only limited benefit, advance care planning should emphasize not the completion of directives but the emotional preparation of patients and families for future crises. The existentialist Albert Camus might suggest that physicians should warn patients and families that momentous, unforeseeable decisions lie ahead. Then, when the crisis hits, physicians should provide guidance; should help make decisions despite the inevitable uncertainties; should share responsibility for those decisions; and, above all, should courageously see patients and families through the fearsome experience of dying. PMID:17606961

  14. Kalman meets neuron - the intersection of control theory and neuroscience

    NASA Astrophysics Data System (ADS)

    Schiff, Steven

    2009-03-01

    Since the 1950s, we have developed mature theories of modern control theory and computational neuroscience with almost no interaction between these disciplines. With the advent of computationally efficient nonlinear Kalman filtering techniques, along with improved neuroscience models which provide increasingly accurate reconstruction of dynamics in a variety of important normal and disease states in the brain, the prospects for a synergistic interaction between these fields are now strong. I will show recent examples of the use of nonlinear control theory for the assimilation and control of single neuron dynamics, a novel framework for dynamic clamp, the modulation of oscillatory wave dynamics in brain cortex, a control framework for Parkinsonian dynamics and seizures, and the use of optimized parameter model networks to assimilate complex network data.

  15. Advanced Design and Implementation of a Control Architecture for Long Range Autonomous Planetary Rovers

    NASA Technical Reports Server (NTRS)

    Martin-Alvarez, A.; Hayati, S.; Volpe, R.; Petras, R.

    1999-01-01

    An advanced design and implementation of a Control Architecture for Long Range Autonomous Planetary Rovers is presented using a hierarchical top-down task decomposition, and the common structure of each design is presented based on feedback control theory. Graphical programming is presented as a common intuitive language for the design when a large design team is composed of managers, architecture designers, engineers, programmers, and maintenance personnel. The whole design of the control architecture consists in the classic control concepts of cyclic data processing and event-driven reaction to achieve all the reasoning and behaviors needed. For this purpose, a commercial graphical tool is presented that includes the mentioned control capabilities. Messages queues are used for inter-communication among control functions, allowing Artificial Intelligence (AI) reasoning techniques based on queue manipulation. Experimental results show a highly autonomous control system running in real time on top the JPL micro-rover Rocky 7 controlling simultaneously several robotic devices. This paper validates the sinergy between Artificial Intelligence and classic control concepts in having in advanced Control Architecture for Long Range Autonomous Planetary Rovers.

  16. Immunotherapy and complexity: overcoming barriers to control of advanced cancer.

    PubMed

    Lage, Agustin

    2014-01-01

    Recent advances in fundamental immunology are changing paradigms for management of advanced cancer, now acknowledged as a chronic disease whose prevalence will increase, and one whose complexity makes it difficult to control. Immunotherapy is emerging as an alternative, with new monoclonal antibodies, therapeutic vaccines and deeper understanding of fundamental phenomena in the interaction between tumor and immune system. These novel insights concern mechanisms of programmed contraction of the immune response, characterization of molecular and cellular markers of immunosenescence, the dual role of inflammation, characterization of myeloid-derived suppressor cells and cancer stem cells, and the phenomena of immunogenic apoptosis and oncogene addiction. Additionally, new data drive a deeper understanding of four barriers to overcome in control of advanced cancer: the complexity of biological systems, tumor heterogeneity, tumor mutation rates, and human genome-environment mismatch. The new landscape points to six main strategies: manage advanced cancer as a chronic disease, find relevant molecular markers for patient stratification, develop a rationale for therapeutic combinations, target regulatory control loops in the immune system, expand mathematical modeling capacity, and evaluate complex health intervention packages in real-world conditions. These transitions in cancer immunotherapy research are illustrated in this paper through description of ongoing projects at Cuba's Molecular Immunology Center. PMID:25208123

  17. Spectrophotometric Procedure for Fast Reactor Advanced Coolant Manufacture Control

    NASA Astrophysics Data System (ADS)

    Andrienko, O. S.; Egorov, N. B.; Zherin, I. I.; Indyk, D. V.

    2016-01-01

    The paper describes a spectrophotometric procedure for fast reactor advanced coolant manufacture control. The molar absorption coefficient of dimethyllead dibromide with dithizone was defined as equal to 68864 ± 795 l·mole-1·cm-1, limit of detection as equal to 0.583 · 10-6 g/ml. The spectrophotometric procedure application range was found to be equal to 37.88 - 196.3 g. of dimethyllead dibromide in the sample. The procedure was used within the framework of the development of the method of synthesis of the advanced coolant for fast reactors.

  18. Research and control of advanced schistosomiasis japonica in China.

    PubMed

    Wu, Wei; Feng, Aicheng; Huang, Yixin

    2015-01-01

    Among the three main schistosomes (Schistosoma japonicum, Schistosoma mansoni, and Schistosoma haematobium) known to infect humans, S. japonicum causes the most serious pathological lesions. In China, only schistosomiasis japonica is transmitted. From the 1950s, massive epidemiological investigations and active control measures for schistosomiasis japonica have been carried out. At the early stage of schistosomiasis control program, there were about 12 million schistosomiasis patients, and about 5% of schistosomiasis patients belong to advanced patients, which was 600,000. After more than a half century of active schistosomiasis control work, the schistosomiasis situation has been reduced markedly. The nearest epidemiological investigation showed that, by the end of 2012, there were still 240,000 schistosomiasis patients with the descent rate of 98% and 30,000 advanced patients with the descent rate of 95%. This paper reviews the rich experiences of advanced schistosomiasis research and control in China, including that the epidemiology researches confirm there is a family aggregation of advanced schistosomiasis and advanced schistosomiasis patients have no significance to the schistosomiasis transmission in transmission-interrupted areas but still are an infection source in endemic areas; pathogenic mechanism researches verify that genetic factors and immunoregulation play important roles in the disease developing process; ultrasound image examinations are used not only in the diagnosis and differential diagnosis of advanced schistosomiasis but also in the guidance of treatment and evaluation of therapeutic effects and, furthermore, in the risk predictions of portal hypertension and upper gastrointestinal hemorrhage; clinical practices demonstrate that praziquantel can be used in most of advanced schistosomiasis patients, and the therapy not only can interrupt the schistosomiasis transmission somewhat but also is favorable for liver fibrosis improvement; the

  19. Advanced actuators for the control of large space structures

    NASA Technical Reports Server (NTRS)

    Downer, James; Hockney, Richard; Johnson, Bruce; Misovec, Kathleen

    1993-01-01

    The objective of this research was to develop advanced six-degree-of-freedom actuators employing magnetic suspensions suitable for the control of structural vibrations in large space structures. The advanced actuators consist of a magnetically suspended mass that has three-degrees-of-freedom in both translation and rotation. The most promising of these actuators featured a rotating suspended mass providing structural control torques in a manner similar to a control moment gyro (CMG). These actuators employ large-angle-magnetic suspensions that allow gimballing of the suspended mass without mechanical gimbals. Design definitions and sizing algorithms for these CMG type as well as angular reaction mass actuators based on multi-degree-of-freedom magnetic suspensions were developed. The performance of these actuators was analytically compared with conventional reaction mass actuators for a simple space structure model.

  20. Planner-Based Control of Advanced Life Support Systems

    NASA Technical Reports Server (NTRS)

    Muscettola, Nicola; Kortenkamp, David; Fry, Chuck; Bell, Scott

    2005-01-01

    The paper describes an approach to the integration of qualitative and quantitative modeling techniques for advanced life support (ALS) systems. Developing reliable control strategies that scale up to fully integrated life support systems requires augmenting quantitative models and control algorithms with the abstractions provided by qualitative, symbolic models and their associated high-level control strategies. This will allow for effective management of the combinatorics due to the integration of a large number of ALS subsystems. By focusing control actions at different levels of detail and reactivity we can use faster: simpler responses at the lowest level and predictive but complex responses at the higher levels of abstraction. In particular, methods from model-based planning and scheduling can provide effective resource management over long time periods. We describe reference implementation of an advanced control system using the IDEA control architecture developed at NASA Ames Research Center. IDEA uses planning/scheduling as the sole reasoning method for predictive and reactive closed loop control. We describe preliminary experiments in planner-based control of ALS carried out on an integrated ALS simulation developed at NASA Johnson Space Center.

  1. Modern control theory for Army missile guidance

    NASA Astrophysics Data System (ADS)

    Travassos, R. H.; Levari, H.; Gupta, N. K.

    1982-11-01

    A Singular perturbation guidance law has been developed for medium-range surface-to-air missiles. This guidance law is a significant extension of a previously developed guidance law for short-range missiles; in medium-range intercepts, the problem of energy management should be addressed in addition to homing guidance. The mathematical formulation has been simplified by introducing separation of time scales. Target Trajectory Estimation: A recursive algorithm for estimation of autoregressive moving average (ARMA) model parameters from noisy samples has been developed. Application of this algorithm to parameter estimation problems has exhibited its fast convergence and unbiasedness in the presence of noise, even with short data records. The algorithm has two versions, a Recursive Maximum Likelihood (RML) form and a Recursive Prediction Error (RPE) form, both of which possess a parallel structure that makes them highly suitable for parallel-processing implementation. Adaptive autopilots: Lattice-form algorithms have been developed for fast, recursive identification and control of time-varying systems. These algorithms have excellent numerical properties and a modular structure that makes them suitable for on-board real-time implementation.

  2. Advanced X-ray Astrophysics Facility thermal control

    NASA Technical Reports Server (NTRS)

    Fritz, C. G.

    1983-01-01

    A conceptual active/passive thermal control system design is presented for the Advanced X-ray Astrophysics Facility (AXAF), where the design variables considered in system optimization were vehicle orientation for environmental extremes, thermal coating properties, and insulation materials. Because power and weight are at a premium, the design was limited to one power module, resulting in a thermal control limit of 441 W of regulated power. The present study has determined that all thermal control objectives for AXAF's instruments can be met by the design considered. The thermal resistance schematics employed in this conceptual study are presented, together with simulated performance characteristics.

  3. Development of Advanced Casing Treatments for Flow Control

    NASA Technical Reports Server (NTRS)

    Keith, Theo G., Jr.; Tsung, Fu-Lin

    2001-01-01

    Under the Base R&T and Ultra Efficient Engine Technology programs, the NASA-Goddard Space Flight Center Compressor Branch is investigating flow control strategies required to increase the loading and efficiency of core compressors while maintaining current levels of operability. Flow-control strategies being studied include advanced casing treatments, wall jet injection, and blade-tip injection for compressor stability enhancement, directed jets for surface boundary layer control, and vortex-generating devices. The use of computational fluid dynamics (CFD) simulations to assess the effectiveness of flow-control devices and to guide their design is a key element in this research. CFD simulations serve to screen potential flow-control concepts at a lower cost than executing physical experiments in turbomachinery facilities. CFD simulations also provide guidance in designing physical experiments for those flow control concepts, which appear promising.

  4. Advanced CO2 removal process control and monitor instrumentation development

    NASA Technical Reports Server (NTRS)

    Heppner, D. B.; Dalhausen, M. J.; Klimes, R.

    1982-01-01

    A progam to evaluate, design and demonstrate major advances in control and monitor instrumentation was undertaken. A carbon dioxide removal process, one whose maturity level makes it a prime candidate for early flight demonstration was investigated. The instrumentation design incorporates features which are compatible with anticipated flight requirements. Current electronics technology and projected advances are included. In addition, the program established commonality of components for all advanced life support subsystems. It was concluded from the studies and design activities conducted under this program that the next generation of instrumentation will be greatly smaller than the prior one. Not only physical size but weight, power and heat rejection requirements were reduced in the range of 80 to 85% from the former level of research and development instrumentation. Using a microprocessor based computer, a standard computer bus structure and nonvolatile memory, improved fabrication techniques and aerospace packaging this instrumentation will greatly enhance overall reliability and total system availability.

  5. PREFACE: 12th European Workshop on Advanced Control and Diagnosis (ACD 2015)

    NASA Astrophysics Data System (ADS)

    Straka, Ondřej; Punčochář, Ivo; Duník, Jindřich

    2015-11-01

    The 12th European Workshop on Advanced Control and Diagnosis (ACD 2015) took place at the Research Centre NTIS - New Technologies for the Information Society, Faculty of Applied Sciences, University of West Bohemia, Pilsen, Czech Republic, on November 19 - 20, 2015. The annual European Workshop on Advanced Control and Diagnosis has been organized since 2003 by Control Engineering departments of several European universities in Germany, France, the UK, Poland, Italy, Hungary, and Denmark to bring together senior and junior academics and engineers from diverse fields of automatic control, fault detection, and signal processing. The workshop provides an opportunity for researchers and developers to present their recent theoretical developments, practical applications, or even open problems. It also offers a great opportunity for industrial partners to express their needs and priorities and to review the current activities in the fields. A total of 74 papers have been submitted for ACD 2015. Based on the peer reviews 48 papers were accepted for the oral presentation and 10 papers for the poster presentation. The accepted papers covered areas of control theory and applications, identification, estimation, signal processing, and fault detection. In addition, four excellent plenary lectures were delivered by Prof. Fredrik Gustafsson (Automotive Sensor Mining for Tire Pressure Monitoring), Prof. Vladimír Havlena (Advanced Process Control for Energy Efficiency), Prof. Silvio Simani (Advanced Issues on Wind Turbine Modelling and Control), and Prof. Robert Babuška (Learning Control in Robotics). The ACD 2015 was for the first time in the workshop history co-sponsored by the International Federation of Automatic Control (IFAC). On behalf of the ACD 2015 organising committee, we would like to thank all those who prepared and submitted papers, participated in the peer review process, supported, and attended the workshop.

  6. Cooperative control theory and integrated flight and propulsion control

    NASA Technical Reports Server (NTRS)

    Schmidt, David K.; Schierman, John D.

    1995-01-01

    The major contribution of this research was the exposition of the fact that airframe and engine interactions could be present, and their effects could include loss of stability and performance of the control systems. Also, the significance of two directional, as opposed to one-directional, coupling was identified and explained. A multivariable stability and performance analysis methodology was developed, and applied to several candidate aircraft configurations. In these example evaluations, the significance of these interactions was underscored. Also exposed was the fact that with interactions present along with some integrated control approaches, the engine command/limiting logic (which represents an important nonlinear component of the engine control system) can impact closed-loop airframe/engine system stability. Finally, a brief investigation of control-law synthesis techniques appropriate for the class of systems was pursued, and it was determined that multivariable techniques, including model-following formulations of LQG and/or H infinity methods, showed promise. However, for practical reasons, decentralized control architectures are preferred, which is an architecture incompatible with these synthesis methods. The major contributions of the second phase of the grant was the development of conditions under which no decentralized controller could achieve closed loop system requirements on stability and/or performance. Sought were conditions that depended only on properties of the plant and the requirement, and independent of any particular control law or synthesis approach. Therefore, they could be applied a priori, before synthesis of a candidate control law. Under this grant, such conditions were found regarding stability, and encouraging initial results were obtained regarding performance.

  7. Moving Beyond Conventional Wisdom: Advancements in Cross-Cultural Theories of Leadership, Conflict, and Teams.

    PubMed

    Gibson, Cristina B; McDaniel, Dana M

    2010-07-01

    In this article, we discuss the importance of a cross-cultural approach to organizational behavior. To do so, we illustrate how cross-cultural research in the past two decades has enabled us to reconceptualize constructs, revise models, and extend boundary conditions in traditional organizational behavior theories. We focus on three domains-teams, leadership, and conflict-and review cross-cultural empirical evidence that has extended several theories in each of these domains. We support the claim that even well-established organizational behavior theories vary in the extent to which they may be applied unilaterally across cultures, thus identifying the critical need to advance these theories via a cross-cultural research agenda. PMID:26162191

  8. Advanced Control Design for Wind Turbines; Part I: Control Design, Implementation, and Initial Tests

    SciTech Connect

    Wright, A. D.; Fingersh, L. J.

    2008-03-01

    The purpose of this report is to give wind turbine engineers information and examples of the design, testing through simulation, field implementation, and field testing of advanced wind turbine controls.

  9. Recent advances in active control of aircraft cabin noise

    NASA Astrophysics Data System (ADS)

    Mathur, Gopal; Fuller, Christopher

    2002-11-01

    Active noise control techniques can provide significant reductions in aircraft interior noise levels without the structural modifications or weight penalties usually associated with passive techniques, particularly for low frequency noise. Our main objective in this presentation is to give a review of active control methods and their applications to aircraft cabin noise reduction with an emphasis on recent advances and challenges facing the noise control engineer in the practical application of these techniques. The active noise control method using secondary acoustic sources, e.g., loudspeakers, as control sources for tonal noise reduction is first discussed with results from an active noise control flight test demonstration. An innovative approach of applying control forces directly to the fuselage structure using piezoelectric actuators, known as active structural acoustic control (ASAC), to control cabin noise is then presented. Experimental results from laboratory ASAC tests conducted on a full-scale fuselage and from flight tests on a helicopter will be discussed. Finally, a hybrid active/passive noise control approach for achieving significant broadband noise reduction will be discussed. Experimental results of control of broadband noise transmission through an aircraft structure will be presented.

  10. Advanced Small Perturbation Potential Flow Theory for Unsteady Aerodynamic and Aeroelastic Analyses

    NASA Technical Reports Server (NTRS)

    Batina, John T.

    2005-01-01

    An advanced small perturbation (ASP) potential flow theory has been developed to improve upon the classical transonic small perturbation (TSP) theories that have been used in various computer codes. These computer codes are typically used for unsteady aerodynamic and aeroelastic analyses in the nonlinear transonic flight regime. The codes exploit the simplicity of stationary Cartesian meshes with the movement or deformation of the configuration under consideration incorporated into the solution algorithm through a planar surface boundary condition. The new ASP theory was developed methodically by first determining the essential elements required to produce full-potential-like solutions with a small perturbation approach on the requisite Cartesian grid. This level of accuracy required a higher-order streamwise mass flux and a mass conserving surface boundary condition. The ASP theory was further developed by determining the essential elements required to produce results that agreed well with Euler solutions. This level of accuracy required mass conserving entropy and vorticity effects, and second-order terms in the trailing wake boundary condition. Finally, an integral boundary layer procedure, applicable to both attached and shock-induced separated flows, was incorporated for viscous effects. The resulting ASP potential flow theory, including entropy, vorticity, and viscous effects, is shown to be mathematically more appropriate and computationally more accurate than the classical TSP theories. The formulaic details of the ASP theory are described fully and the improvements are demonstrated through careful comparisons with accepted alternative results and experimental data. The new theory has been used as the basis for a new computer code called ASP3D (Advanced Small Perturbation - 3D), which also is briefly described with representative results.

  11. Advanced interaction media in nuclear power plant control rooms.

    PubMed

    Stephane, Lucas

    2012-01-01

    The shift from analog to digital Instruments (related mainly to information visualization) and Controls in Nuclear Power Plant Main Control Rooms (NPP MCR) is a central current topic of investigation. In NPP MCR, digitalization was implemented gradually, analog and digital systems still coexisting for the two main systems related to safety--Safety Instruments and Control System (SICS) and Process Instruments and Controls System (PICS). My ongoing research focuses on the introduction of Advanced Interaction Media (AIM) such as stereoscopic 3D visualization and multi-touch surfaces in control rooms. This paper proposes a Safety-Centric approach for gathering the Design Rationale needed in the specification of such novel AIM concepts as well as their evaluation through user tests. Beyond methodological research, the final output of the current research is to build an experimental simulator aiming to enhance improvements in Human-Systems Integration (HSI). This paper provides an overview of the topics under consideration. PMID:22317419

  12. ACTS TDMA network control. [Advanced Communication Technology Satellite

    NASA Technical Reports Server (NTRS)

    Inukai, T.; Campanella, S. J.

    1984-01-01

    This paper presents basic network control concepts for the Advanced Communications Technology Satellite (ACTS) System. Two experimental systems, called the low-burst-rate and high-burst-rate systems, along with ACTS ground system features, are described. The network control issues addressed include frame structures, acquisition and synchronization procedures, coordinated station burst-time plan and satellite-time plan changes, on-board clock control based on ground drift measurements, rain fade control by means of adaptive forward-error-correction (FEC) coding and transmit power augmentation, and reassignment of channel capacities on demand. The NASA ground system, which includes a primary station, diversity station, and master control station, is also described.

  13. Microeconomics of advanced process window control for 50-nm gates

    NASA Astrophysics Data System (ADS)

    Monahan, Kevin M.; Chen, Xuemei; Falessi, Georges; Garvin, Craig; Hankinson, Matt; Lev, Amir; Levy, Ady; Slessor, Michael D.

    2002-07-01

    Fundamentally, advanced process control enables accelerated design-rule reduction, but simple microeconomic models that directly link the effects of advanced process control to profitability are rare or non-existent. In this work, we derive these links using a simplified model for the rate of profit generated by the semiconductor manufacturing process. We use it to explain why and how microprocessor manufacturers strive to avoid commoditization by producing only the number of dies required to satisfy the time-varying demand in each performance segment. This strategy is realized using the tactic known as speed binning, the deliberate creation of an unnatural distribution of microprocessor performance that varies according to market demand. We show that the ability of APC to achieve these economic objectives may be limited by variability in the larger manufacturing context, including measurement delays and process window variation.

  14. Parametrized tests of post-Newtonian theory using Advanced LIGO and Einstein Telescope

    SciTech Connect

    Mishra, Chandra Kant; Arun, K. G.; Iyer, Bala R.; Sathyaprakash, B. S.

    2010-09-15

    General relativity has very specific predictions for the gravitational waveforms from inspiralling compact binaries obtained using the post-Newtonian (PN) approximation. We investigate the extent to which the measurement of the PN coefficients, possible with the second generation gravitational-wave detectors such as the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) and the third generation gravitational-wave detectors such as the Einstein Telescope (ET), could be used to test post-Newtonian theory and to put bounds on a subclass of parametrized-post-Einstein theories which differ from general relativity in a parametrized sense. We demonstrate this possibility by employing the best inspiralling waveform model for nonspinning compact binaries which is 3.5PN accurate in phase and 3PN in amplitude. Within the class of theories considered, Advanced LIGO can test the theory at 1.5PN and thus the leading tail term. Future observations of stellar mass black hole binaries by ET can test the consistency between the various PN coefficients in the gravitational-wave phasing over the mass range of 11-44M{sub {center_dot}}. The choice of the lower frequency cutoff is important for testing post-Newtonian theory using the ET. The bias in the test arising from the assumption of nonspinning binaries is indicated.

  15. Applications of fiber optic sensors in advanced engine controls

    NASA Astrophysics Data System (ADS)

    Nitka, Edward F., II

    1989-06-01

    Measured parameters, operating ranges, accuracy requirements, environmental constraints, and speed of response of fiber optic sensors are identified for three categories of engines. The three engine categories are: (1) current turbojet, turbofan, and turboprop engines; (2) next generation and turbofan engines to be built in the 1990s; and (3) advanced supersonic/hypersonic engines represented by ramjet, scramjet, and air-turbo-ramjet concepts. The key development and test efforts in engine control applications of fiber optic sensors are discussed.

  16. Coal surface control for advanced fine coal flotation

    SciTech Connect

    Fuerstenau, D.W.; Sastry, K.V.; Hanson, J.S.; Harris, G.; Sotillo, F.; Diao, J.; De, A. ); Somasundaran, P.; Harris, C.C.; Vasudevan, T.; Liu, D.; Li, C. ); Hu, Weibai; Zou, Y.; Chen, W. ); Choudhry, V.; Sehgal, R.; Ghosh, A. )

    1991-03-22

    The main goal of the project is to characterize the surface and control the behavior of coal during advanced flotation processing in order to achieve an overall objective of near-total pyritic sulfur removal with a high Btu recovery. Also, investigation of the effects of weathering on the surface characteristics of coal is another important aspect of this project. The effect of butanol, dodecane, lime, calcium cyanide, hydrogen peroxide, and ph on flotation performance is discussed. 2 refs., 26 figs., 18 tabs.

  17. Definition study for temperature control in advanced protein crystal growth

    NASA Technical Reports Server (NTRS)

    Nyce, Thomas A.; Rosenberger, Franz; Sowers, Jennifer W.; Monaco, Lisa A.

    1990-01-01

    Some of the technical requirements for an expedient application of temperature control to advanced protein crystal growth activities are defined. Lysozome was used to study the effects of temperature ramping and temperature gradients for nucleation/dissolution and consecutive growth of sizable crystals and, to determine a prototype temperature program. The solubility study was conducted using equine serum albumin (ESA) which is an extremely stable, clinically important protein due to its capability to bind and transport many different small ions and molecules.

  18. A flexible architecture for advanced process control solutions

    NASA Astrophysics Data System (ADS)

    Faron, Kamyar; Iourovitski, Ilia

    2005-05-01

    Advanced Process Control (APC) is now mainstream practice in the semiconductor manufacturing industry. Over the past decade and a half APC has evolved from a "good idea", and "wouldn"t it be great" concept to mandatory manufacturing practice. APC developments have primarily dealt with two major thrusts, algorithms and infrastructure, and often the line between them has been blurred. The algorithms have evolved from very simple single variable solutions to sophisticated and cutting edge adaptive multivariable (input and output) solutions. Spending patterns in recent times have demanded that the economics of a comprehensive APC infrastructure be completely justified for any and all cost conscious manufacturers. There are studies suggesting integration costs as high as 60% of the total APC solution costs. Such cost prohibitive figures clearly diminish the return on APC investments. This has limited the acceptance and development of pure APC infrastructure solutions for many fabs. Modern APC solution architectures must satisfy the wide array of requirements from very manual R&D environments to very advanced and automated "lights out" manufacturing facilities. A majority of commercially available control solutions and most in house developed solutions lack important attributes of scalability, flexibility, and adaptability and hence require significant resources for integration, deployment, and maintenance. Many APC improvement efforts have been abandoned and delayed due to legacy systems and inadequate architectural design. Recent advancements (Service Oriented Architectures) in the software industry have delivered ideal technologies for delivering scalable, flexible, and reliable solutions that can seamlessly integrate into any fabs" existing system and business practices. In this publication we shall evaluate the various attributes of the architectures required by fabs and illustrate the benefits of a Service Oriented Architecture to satisfy these requirements. Blue

  19. Testing State-Space Controls for the Controls Advanced Research Turbine: Preprint

    SciTech Connect

    Wright, A. D.; Fingersh, L. J.; Balas, M. J.

    2006-01-01

    Control can improve wind turbine performance by enhancing energy capture and reducing dynamic loads. At the National Renewable Energy Laboratory, we are implementing and testing state-space controls on the Controls Advanced Research Turbine (CART), a turbine specifically configured to test advanced controls. We show the design of control systems to regulate turbine speed in Region 3 using rotor collective pitch and reduce dynamic loads in Regions 2 and 3 using generator torque. These controls enhance damping in the first drive train torsion mode. We base these designs on sensors typically used in commercial turbines. We evaluate the performance of these controls by showing field test results. We also compare results from these modern controllers to results from a baseline proportional integral controller for the CART. Finally, we report conclusions to this work and outline future studies.

  20. Screening studies of advanced control concepts for airbreathing engines

    NASA Technical Reports Server (NTRS)

    Ouzts, Peter J.; Lorenzo, Carl F.; Merrill, Walter C.

    1993-01-01

    The application of advanced control concepts to airbreathing engines may yield significant improvements in aircraft/engine performance and operability. Accordingly, the NASA Lewis Research Center has conducted screening studies of advanced control concepts for airbreathing engines to determine their potential impact on turbine engine performance and operability. The purpose of the studies was to identify concepts which offered high potential yet may incur high research and development risk. A target suite of proposed concepts was formulated by NASA and industry. These concepts were evaluated in a two phase study to quantify each concept's impact on desired engine characteristics. To aid in the evaluation, three target aircraft/engine combinations were considered: a military high performance fighter mission, a high speed civil transport mission, and a civil tiltrotor mission. Each of the advanced control concepts considered in the study were defined and described. The concept's potential impact on engine performance was determined. Relevant figures of merit on which to evaluate the concepts were also determined. Finally, the concepts were ranked with respect to the target aircraft/engine missions.

  1. Screening studies of advanced control concepts for airbreathing engines

    NASA Technical Reports Server (NTRS)

    Ouzts, Peter J.; Lorenzo, Carl F.; Merrill, Walter C.

    1992-01-01

    The application of advanced control concepts to airbreathing engines may yield significant improvements in aircraft/engine performance and operability. Accordingly, the NASA Lewis Research Center has conducted screening studies of advanced control concepts for airbreathing engines to determine their potential impact on turbine engine performance and operability. The purpose of the studies was to identify concepts which offered high potential yet may incur high research and development risk. A target suite of proposed concepts was formulated by NASA and industry. These concepts were evaluated in a two phase study to quantify each concept's impact on desired engine characteristics. To aid in the evaluation, three target aircraft/engine combinations were considered: a military high performance fighter mission, a high speed civil transport mission, and a civil tiltrotor mission. Each of the advanced control concepts considered in the study were defined and described. The concept's potential impact on engine performance was determined. Relevant figures of merit on which to evaluate the concepts were also determined. Finally, the concepts were ranked with respect to the target aircraft/engine missions.

  2. Improved safety in advanced control complexes, without side effects

    SciTech Connect

    Harmon, D.L.

    1997-12-01

    If we only look for a moment at the world around us, it is obvious that advances in digital electronic equipment and Human-System Interface (HSI) technology are occurring at a phenomenal pace. This is evidenced from our home entertainment systems to the dashboard and computer-based operation of our new cars. Though the nuclear industry has less vigorously embraced these advances, their application is being implemented through individual upgrades to current generation nuclear plants and as plant-wide control complexes for advanced plants. In both venues modem technology possesses widely touted advantages for improving plant availability as well as safety. The well-documented safety benefits of digital Instrumentation and Controls (I&C) include higher reliability resulting from redundancy and fault tolerance, inherent self-test and self-diagnostic capabilities which have replaced error-prone human tasks, resistance to setpoint drift increasing available operating margins, and the ability to run complex, real-time, computer-based algorithms directly supporting an operator`s monitoring and control task requirements. 22 refs., 3 figs., 5 tabs.

  3. Advanced Environmental Monitoring and Control Program: Technology Development Requirements

    NASA Technical Reports Server (NTRS)

    Jan, Darrell (Editor); Seshan, Panchalam (Editor); Ganapathi, Gani (Editor); Schmidt, Gregory (Editor); Doarn, Charles (Editor)

    1996-01-01

    Human missions in space, from the International Space Station on towards potential human exploration of the moon, Mars and beyond into the solar system, will require advanced systems to maintain an environment that supports human life. These systems will have to recycle air and water for many months or years at a time, and avoid harmful chemical or microbial contamination. NASA's Advanced Environmental Monitoring and Control program has the mission of providing future spacecraft with advanced, integrated networks of microminiaturized sensors to accurately determine and control the physical, chemical and biological environment of the crew living areas. This document sets out the current state of knowledge for requirements for monitoring the crew environment, based on (1) crew health, and (2) life support monitoring systems. Both areas are updated continuously through research and space mission experience. The technologies developed must meet the needs of future life support systems and of crew health monitoring. These technologies must be inexpensive and lightweight, and use few resources. Using these requirements to continue to push the state of the art in miniaturized sensor and control systems will produce revolutionary technologies to enable detailed knowledge of the crew environment.

  4. Advanced Rooftop Control (ARC) Retrofit: Field-Test Results

    SciTech Connect

    Wang, Weimin; Katipamula, Srinivas; Ngo, Hung; Underhill, Ronald M.; Taasevigen, Danny J.; Lutes, Robert G.

    2013-07-31

    The multi-year research study was initiated to find solutions to improve packaged equipment operating efficiency in the field. Pacific Northwest National Laboratory (PNNL), with funding from the U.S. Department of Energy’s (DOE’s) Building Technologies Office (BTO) and Bonneville Power Administration (BPA) conducted this research, development and demonstration (RD&D) study. Packaged equipment with constant speed supply fans is designed to provide ventilation at the design rate at all times when the fan is operating as required by building code. Although there are a number of hours during the day when a building may not be fully occupied or the need for ventilation is lower than designed, the ventilation rate cannot be adjusted easily with a constant speed fan. Therefore, modulating the supply fan in conjunction with demand controlled ventilation (DCV) will not only reduce the coil energy but also reduce the fan energy. The objective of this multi-year research, development and demonstration project was to determine the magnitude of energy savings achievable by retrofitting existing packaged rooftop air conditioners with advanced control strategies not ordinarily used for packaged units. First, through detailed simulation analysis, it was shown that significant energy (between 24% and 35%) and cost savings (38%) from fan, cooling and heating energy consumption could be realized when packaged air conditioning units with gas furnaces are retrofitted with advanced control packages (combining multi-speed fan control, integrated economizer controls and DCV). The simulation analysis also showed significant savings for heat pumps (between 20% and 60%). The simulation analysis was followed by an extensive field test of a retrofittable advanced rooftop unit (RTU) controller.

  5. Reliability, Safety and Error Recovery for Advanced Control Software

    NASA Technical Reports Server (NTRS)

    Malin, Jane T.

    2003-01-01

    For long-duration automated operation of regenerative life support systems in space environments, there is a need for advanced integration and control systems that are significantly more reliable and safe, and that support error recovery and minimization of operational failures. This presentation outlines some challenges of hazardous space environments and complex system interactions that can lead to system accidents. It discusses approaches to hazard analysis and error recovery for control software and challenges of supporting effective intervention by safety software and the crew.

  6. Theory of the control of structures by low authority controllers

    NASA Technical Reports Server (NTRS)

    Aubrun, J. N.

    1978-01-01

    The novel idea presented is based on the observation that if a structure is controlled by distributed systems of sensors and actuators with limited authority, i.e., if the controller is allowed to modify only moderately the natural modes and frequencies of the structure, then it should be possible to apply root perturbation techniques to predict analytically the behavior of the total system. Attention is given to the root perturbation formula first derived by Jacobi for infinitesimal perturbations which neglect the induced eigenvector perturbation, a more general form of Jacobi's formula, first-order structural equations and modal state vectors, state-space equations for damper-augmented structures, and modal damping prediction formulas.

  7. Coal surface control for advanced physical fine coal cleaning technologies

    SciTech Connect

    Morsi, B.I.; Chiang, S.H.; Sharkey, A.; Blachere, J.; Klinzing, G.; Araujo, G.; Cheng, Y.S.; Gray, R.; Streeter, R.; Bi, H.; Campbell, P.; Chiarlli, P.; Ciocco, M.; Hittle, L.; Kim, S.; Kim, Y.; Perez, L.; Venkatadri, R.

    1992-01-01

    This final report presents the research work carried out on the Coal Surface Control for Advanced Physical Fine Coal Cleaning Technologies project, sponsored by the US Department of Energy, Pittsburgh Energy Technology Center (DOE/PETC). The project was to support the engineering development of the selective agglomeration technology in order to reduce the sulfur content of US coals for controlling SO[sub 2] emissions (i.e., acid rain precursors). The overall effort was a part of the DOE/PETCs Acid Rain Control Initiative (ARCI). The overall objective of the project is to develop techniques for coal surface control prior to the advanced physical fine coal cleaning process of selective agglomeration in order to achieve 85% pyrite sulfur rejection at an energy recovery greater than 85% based on run-of-mine coal. The surface control is meant to encompass surface modification during grinding and laboratory beneficiation testing. The project includes the following tasks: Project planning; methods for analysis of samples; development of standard beneficiation test; grinding studies; modification of particle surface; and exploratory R D and support. The coal samples used in this project include three base coals, Upper Freeport - Indiana County, PA, Pittsburgh NO. 8 - Belmont County, OH, and Illinois No. 6 - Randolph County, IL, and three additional coals, Upper Freeport - Grant County- WV, Kentucky No. 9 Hopkins County, KY, and Wyodak - Campbell County, WY. A total of 149 drums of coal were received.

  8. System Engineering and Integration of Controls for Advanced Life Support

    NASA Technical Reports Server (NTRS)

    Overland, David; Hoo, Karlene; Ciskowski, Marvin

    2006-01-01

    The Advanced Integration Matrix (AIM) project at the Johnson Space Center (JSC) was chartered to study and solve systems-level integration issues for exploration missions. One of the first issues identified was an inability to conduct trade studies on control system architectures due to the absence of mature evaluation criteria. Such architectures are necessary to enable integration of regenerative life support systems. A team was formed to address issues concerning software and hardware architectures and system controls.. The team has investigated what is required to integrate controls for the types of non-linear dynamic systems encountered in advanced life support. To this end, a water processing bioreactor testbed is being developed which will enable prototyping and testing of integration strategies and technologies. Although systems such as the water bioreactors exhibit the complexities of interactions between control schemes most vividly, it is apparent that this behavior and its attendant risks will manifest itself among any set of interdependent autonomous control systems. A methodology for developing integration requirements for interdependent and autonomous systems is a goal of this team and this testbed. This paper is a high-level summary of the current status of the investigation, the issues encountered, some tentative conclusions, and the direction expected for further research.

  9. How to fly an aircraft with control theory and splines

    NASA Technical Reports Server (NTRS)

    Karlsson, Anders

    1994-01-01

    When trying to fly an aircraft as smoothly as possible it is a good idea to use the derivatives of the pilot command instead of using the actual control. This idea was implemented with splines and control theory, in a system that tries to model an aircraft. Computer calculations in Matlab show that it is impossible to receive enough smooth control signals by this way. This is due to the fact that the splines not only try to approximate the test function, but also its derivatives. A perfect traction is received but we have to pay in very peaky control signals and accelerations.

  10. Approximation in control of flexible structures, theory and application

    NASA Technical Reports Server (NTRS)

    Gibson, J. S.

    1983-01-01

    The sense in which the feedback control law based on an approximate finite dimensional model of a continuous structure approximates a control law which is optimal for the distributed, or infinite dimensional, model of the structure is studied. From the analysis of the various control and stability issues associated with this basis question, useful information for designing finite dimensional compensators which produce near-optimal performance in infinite dimensional systems is gained. Some of the important predictions that can be made about large-order finite dimensional control laws, using the theory of infinite dimensional Riccati equations are indicated.

  11. Integrated metrology: an enabler for advanced process control (APC)

    NASA Astrophysics Data System (ADS)

    Schneider, Claus; Pfitzner, Lothar; Ryssel, Heiner

    2001-04-01

    Advanced process control (APC) techniques become more and more important as short innovation cycles in microelectronics and a highly competitive market requires cost-effective solutions in semiconductor manufacturing. APC marks a paradigm shift from statistically based techniques (SPC) using monitor wafers for sampling measurement data towards product wafer control. The APC functionalities including run-to-run control, fault detection, and fault analysis allow to detect process drifts and excursions at an early stage and to minimize the number of misprocessed wafers. APC is being established as part of factory control systems through the definition of an APC framework. A precondition for APC is the availability of sensors and measurement methods providing the necessary wafer data. This paper discusses integrated metrology as an enabler for APC and demonstrates practical implementations in semiconductor manufacturing.

  12. An integrated theory for predicting the hydrothermomechanical response of advanced composite structural components

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.; Lark, R. F.; Sinclair, J. H.

    1977-01-01

    A theory is developed for predicting the hydrothermomechanical response of advanced composite structural components. The combined hydrothermal effects on the mechanical properties of unidirectional composites loaded along the material axis and off-axis, and of angleplied laminates are also evaluated. The materials investigated consist of neat PR-288 epoxy matrix resin and an AS-type graphite fiber/PR-288 resin unidirectional composite.

  13. Local control theory in trajectory-based nonadiabatic dynamics

    SciTech Connect

    Curchod, Basile F. E.; Penfold, Thomas J.; Rothlisberger, Ursula; Tavernelli, Ivano

    2011-10-15

    In this paper, we extend the implementation of nonadiabatic molecular dynamics within the framework of time-dependent density-functional theory in an external field described in Tavernelli et al.[Phys. Rev. A 81, 052508 (2010)] by calculating on-the-fly pulses to control the population transfer between electronic states using local control theory. Using Tully's fewest switches trajectory surface hopping method, we perform MD to control the photoexcitation of LiF and compare the results to quantum dynamics (QD) calculations performed within the Heidelberg multiconfiguration time-dependent Hartree package. We show that this approach is able to calculate a field that controls the population transfer between electronic states. The calculated field is in good agreement with that obtained from QD, and the differences that arise are discussed in detail.

  14. Refinements and Tests of an Advanced Controller to Mitigate Fatigue Loads in the Controls Advanced Research Turbine: Preprint

    SciTech Connect

    Wright, A.; Fleming, P.

    2010-12-01

    Wind turbines are complex, nonlinear, dynamic systems forced by aerodynamic, gravitational, centrifugal, and gyroscopic loads. The aerodynamics of wind turbines are nonlinear, unsteady, and complex. Turbine rotors are subjected to a complicated 3-D turbulent wind inflow field, with imbedded coherent vortices that drive fatigue loads and reduce lifetime. Design of control algorithms for wind turbines must account for multiple control objectives. Future large multi-megawatt turbines must be designed with lighter weight structures, using active controls to mitigate fatigue loads, while maximizing energy capture. Active damping should be added to these dynamic structures to maintain stability for operation in a complex environment. At the National Renewable Energy Laboratory (NREL), we have designed, implemented, and tested advanced controls to maximize energy extraction and reduce structural dynamic loads. These control designs are based on linear models of the turbine that are generated by specialized modeling software. In this paper, we present field test results of an advanced control algorithm to mitigate blade, tower, and drivetrain loads in Region 3.

  15. Control theory and splines, applied to signature storage

    NASA Technical Reports Server (NTRS)

    Enqvist, Per

    1994-01-01

    In this report the problem we are going to study is the interpolation of a set of points in the plane with the use of control theory. We will discover how different systems generate different kinds of splines, cubic and exponential, and investigate the effect that the different systems have on the tracking problems. Actually we will see that the important parameters will be the two eigenvalues of the control matrix.

  16. Integrated control-system design via generalized LQG (GLQG) theory

    NASA Technical Reports Server (NTRS)

    Bernstein, Dennis S.; Hyland, David C.; Richter, Stephen; Haddad, Wassim M.

    1989-01-01

    Thirty years of control systems research has produced an enormous body of theoretical results in feedback synthesis. Yet such results see relatively little practical application, and there remains an unsettling gap between classical single-loop techniques (Nyquist, Bode, root locus, pole placement) and modern multivariable approaches (LQG and H infinity theory). Large scale, complex systems, such as high performance aircraft and flexible space structures, now demand efficient, reliable design of multivariable feedback controllers which optimally tradeoff performance against modeling accuracy, bandwidth, sensor noise, actuator power, and control law complexity. A methodology is described which encompasses numerous practical design constraints within a single unified formulation. The approach, which is based upon coupled systems or modified Riccati and Lyapunov equations, encompasses time-domain linear-quadratic-Gaussian theory and frequency-domain H theory, as well as classical objectives such as gain and phase margin via the Nyquist circle criterion. In addition, this approach encompasses the optimal projection approach to reduced-order controller design. The current status of the overall theory will be reviewed including both continuous-time and discrete-time (sampled-data) formulations.

  17. Schoenfeld's Problem Solving Theory in a Student Controlled Learning Environment

    ERIC Educational Resources Information Center

    Harskamp, E.; Suhre, C.

    2007-01-01

    This paper evaluates the effectiveness of a student controlled computer program for high school mathematics based on instruction principles derived from Schoenfeld's theory of problem solving. The computer program allows students to choose problems and to make use of hints during different episodes of solving problems. Crucial episodes are:…

  18. Integration of advanced teleoperation technologies for control of space robots

    NASA Technical Reports Server (NTRS)

    Stagnaro, Michael J.

    1993-01-01

    Teleoperated robots require one or more humans to control actuators, mechanisms, and other robot equipment given feedback from onboard sensors. To accomplish this task, the human or humans require some form of control station. Desirable features of such a control station include operation by a single human, comfort, and natural human interfaces (visual, audio, motion, tactile, etc.). These interfaces should work to maximize performance of the human/robot system by streamlining the link between human brain and robot equipment. This paper describes development of a control station testbed with the characteristics described above. Initially, this testbed will be used to control two teleoperated robots. Features of the robots include anthropomorphic mechanisms, slaving to the testbed, and delivery of sensory feedback to the testbed. The testbed will make use of technologies such as helmet mounted displays, voice recognition, and exoskeleton masters. It will allow tor integration and testing of emerging telepresence technologies along with techniques for coping with control link time delays. Systems developed from this testbed could be applied to ground control of space based robots. During man-tended operations, the Space Station Freedom may benefit from ground control of IVA or EVA robots with science or maintenance tasks. Planetary exploration may also find advanced teleoperation systems to be very useful.

  19. Artificial Intelligent Control for a Novel Advanced Microwave Biodiesel Reactor

    NASA Astrophysics Data System (ADS)

    Wali, W. A.; Hassan, K. H.; Cullen, J. D.; Al-Shamma'a, A. I.; Shaw, A.; Wylie, S. R.

    2011-08-01

    Biodiesel, an alternative diesel fuel made from a renewable source, is produced by the transesterification of vegetable oil or fat with methanol or ethanol. In order to control and monitor the progress of this chemical reaction with complex and highly nonlinear dynamics, the controller must be able to overcome the challenges due to the difficulty in obtaining a mathematical model, as there are many uncertain factors and disturbances during the actual operation of biodiesel reactors. Classical controllers show significant difficulties when trying to control the system automatically. In this paper we propose a comparison of artificial intelligent controllers, Fuzzy logic and Adaptive Neuro-Fuzzy Inference System(ANFIS) for real time control of a novel advanced biodiesel microwave reactor for biodiesel production from waste cooking oil. Fuzzy logic can incorporate expert human judgment to define the system variables and their relationships which cannot be defined by mathematical relationships. The Neuro-fuzzy system consists of components of a fuzzy system except that computations at each stage are performed by a layer of hidden neurons and the neural network's learning capability is provided to enhance the system knowledge. The controllers are used to automatically and continuously adjust the applied power supplied to the microwave reactor under different perturbations. A Labview based software tool will be presented that is used for measurement and control of the full system, with real time monitoring.

  20. Simulating advanced life support systems to test integrated control approaches

    NASA Astrophysics Data System (ADS)

    Kortenkamp, D.; Bell, S.

    Simulations allow for testing of life support control approaches before hardware is designed and built. Simulations also allow for the safe exploration of alternative control strategies during life support operation. As such, they are an important component of any life support research program and testbed. This paper describes a specific advanced life support simulation being created at NASA Johnson Space Center. It is a discrete-event simulation that is dynamic and stochastic. It simulates all major components of an advanced life support system, including crew (with variable ages, weights and genders), biomass production (with scalable plantings of ten different crops), water recovery, air revitalization, food processing, solid waste recycling and energy production. Each component is modeled as a producer of certain resources and a consumer of certain resources. The control system must monitor (via sensors) and control (via actuators) the flow of resources throughout the system to provide life support functionality. The simulation is written in an object-oriented paradigm that makes it portable, extensible and reconfigurable.

  1. Advanced interactive displays for deployable command and control centers

    NASA Astrophysics Data System (ADS)

    Jedrysik, Peter A.; Parada, Francisco E.; Stedman, Terrance A.; Zhang, Jingyuan

    2003-09-01

    Command and control in today's battlefield environment requires efficient and effective control of massive amounts of constantly changing information from a variety of databases and real-time sensors. Using advanced information technology for presentation and interactive control enables more extensive data fusion and correlation to present an accurate picture of the battlespace to commanders and their staffs. The Interactive DataWall being developed by the Advanced Displays and Intelligent Interfaces (ADII) technology team of the Air Force Research Laboratory's Information Directorate (AFRL/IF) is a strong contender for solving the information management problems facing the 21st century military commander. It provides an ultra high-resolution large screen display with multi-modal, wireless interaction. Commercial off-the-shelf (COTS) technology has been combined with specialized hardware and software developed in-house to provide a unique capability for multimedia data display and control. The technology once isolated to a laboratory environment has been packaged into deployable systems that have been successfully transitioned to support the warfighter in the field.

  2. Biaxial experiments supporting the development of constitutive theories for advanced high-temperature materials

    NASA Technical Reports Server (NTRS)

    Ellis, J. R.

    1988-01-01

    Complex states of stress and strain are introduced into components during service in engineering applications. It follows that analysis of such components requires material descriptions, or constitutive theories, which reflect the tensorial nature of stress and strain. For applications involving stress levels above yield, the situation is more complex in that material response is both nonlinear and history dependent. This has led to the development of viscoplastic constitutive theories which introduce time by expressing the flow and evolutionary equation in the form of time derivatives. Models were developed here which can be used to analyze high temperature components manufactured from advanced composite materials. In parallel with these studies, effort was directed at developing multiaxial testing techniques to verify the various theories. Recent progress in the development of constitutive theories from both the theoretical and experimental viewpoints are outlined. One important aspect is that material descriptions for advanced composite materials which can be implemented in general purpose finite element codes and used for practical design are verified.

  3. Vibroacoustic behavior and noise control studies of advanced composite structures

    NASA Astrophysics Data System (ADS)

    Li, Deyu

    The research presented in this thesis is devoted to the problems of sound transmission and noise transmission control for advanced composite payload fairings. There are two advanced composite fairings under study. The first is a tapered, cylindrical advanced grid-stiffened composite fairing, and the second is a cylindrical ChamberCore composite fairing. A fully coupled mathematical model for characterizing noise transmission into a finite elastic cylindrical structure with application to the ChamberCore fairing is developed. It combines advantages of wave radiation principles and structural-acoustic modal interaction, and provides an ideal noise transmission model that can be extended to other finite cylindrical structures. Structural-acoustic dynamic parameters of the two fairings are obtained using a combination of numerical, analytical, and experimental approaches. An in-situ method for experimentally characterizing sound transmission into the fairings called noise reduction spectrum (NRS) is developed based on noise reduction. The regions of interest in the NRS curves are identified and verified during a passive control investigation, where various fill materials are added into wall-chambers of the ChamberCore fairing. Both Helmholtz resonators (HRs) and long T-shaped acoustic resonators (ARs) are also used to successfully control noise transmission into the ChamberCore fairing. In the process, an accurate model for the resonant frequency calculation and design of cylindrical HRs is derived. Further, a novel and more general model for the design of multi-modal, long, T-shaped ARs is developed, including three new end-correction equations that are validated experimentally. The control results show that noise attenuation is significant in the controlled modes, and the control is also observed in some modes that are not targeted, due to acoustic modal coupling via the structure. Helmholtz resonators are found to produce between 2.0 and 7.7 dB increase in NRS in

  4. Product Distribution Theory for Control of Multi-Agent Systems

    NASA Technical Reports Server (NTRS)

    Lee, Chia Fan; Wolpert, David H.

    2004-01-01

    Product Distribution (PD) theory is a new framework for controlling Multi-Agent Systems (MAS's). First we review one motivation of PD theory, as the information-theoretic extension of conventional full-rationality game theory to the case of bounded rational agents. In this extension the equilibrium of the game is the optimizer of a Lagrangian of the (probability distribution of) the joint stare of the agents. Accordingly we can consider a team game in which the shared utility is a performance measure of the behavior of the MAS. For such a scenario the game is at equilibrium - the Lagrangian is optimized - when the joint distribution of the agents optimizes the system's expected performance. One common way to find that equilibrium is to have each agent run a reinforcement learning algorithm. Here we investigate the alternative of exploiting PD theory to run gradient descent on the Lagrangian. We present computer experiments validating some of the predictions of PD theory for how best to do that gradient descent. We also demonstrate how PD theory can improve performance even when we are not allowed to rerun the MAS from different initial conditions, a requirement implicit in some previous work.

  5. Control system for insertion devices at the advanced photon source

    SciTech Connect

    Makarov, Oleg A.; Den Hartog, Patric; Moog, Elizabeth R.; Smith, Martin L.

    1997-07-01

    Eighteen insertion devices (IDs) are installed at the Advanced Photon Source (APS), and three more are scheduled for installation by the end of this year. A distributed control system for insertion devices at the APS storage ring was created with the Experimental Physics and Industrial Control System (EPICS). The basic components of this system are operator interfaces (OPIs), input output controllers (IOCs), and a local area network that allows the OPI and IOC to communicate. The IOC operates under the VxWorks OS with an EPICS database and a sequencer. The sequencer runs an ID control program written in State Notation Language. The OPI is built with the EPICS tool MEDM and provides display screens with input and output fields and buttons for gap control of the IDs. Global commands like 'open all IDs' are C-shell scripts invoked from the display menu. The algorithms for control and protection of the ID and ID vacuum chamber and the accuracy of gap control are discussed.

  6. Control system for insertion devices at the Advanced Photon Source

    SciTech Connect

    Makarov, O.A.; Den Hartog, P.; Moog, E.R.; Smith, M.L.

    1997-09-01

    Eighteen insertion devices (IDs) are installed at the Advanced Photon Source (APS), and three more are scheduled for installation by the end of this year. A distributed control system for insertion devices at the APS storage ring was created with the Experimental Physics and Industrial Control System (EPICS). The basic components of this system are operator interfaces (OPIs), input output controllers (IOCs), and a local area network that allows the OPI and IOC to communicate. The IOC operates under the VxWorks OS with an EPICS database and a sequencer. The sequencer runs an ID control program written in State Notation Language. The OPI is built with the EPICS tool MEDM and provides display screens with input and output fields and buttons for gap control of the IDs. Global commands like ``open all IDs`` are C-shell scripts invoked from the display menu. The algorithms for control and protection of the ID and ID vacuum chamber and the accuracy of gap control are discussed.

  7. Control system for insertion devices at the advanced photon source

    SciTech Connect

    Makarov, O.A.; Den Hartog, P.; Moog, E.R.; Smith, M.L.

    1997-07-01

    Eighteen insertion devices (IDs) are installed at the Advanced Photon Source (APS), and three more are scheduled for installation by the end of this year. A distributed control system for insertion devices at the APS storage ring was created with the Experimental Physics and Industrial Control System (EPICS). The basic components of this system are operator interfaces (OPIs), input output controllers (IOCs), and a local area network that allows the OPI and IOC to communicate. The IOC operates under the VxWorks OS with an EPICS database and a sequencer. The sequencer runs an ID control program written in State Notation Language. The OPI is built with the EPICS tool MEDM and provides display screens with input and output fields and buttons for gap control of the IDs. Global commands like {open_quotes}open all IDs{close_quotes} are C-shell scripts invoked from the display menu. The algorithms for control and protection of the ID and ID vacuum chamber and the accuracy of gap control are discussed. {copyright} {ital 1997 American Institute of Physics.}

  8. Reviewing the impact of advanced control room technology

    SciTech Connect

    Wilhelmsen, C.A.; Gertman, D.I.; Ostrom, L.T.; Nelson, W.R.; Galyean, W.J.; Byers, J.C.

    1992-08-01

    Progress to date on assessing the nature of the expected changes in human performance and risk associated with the introduction of digital control, instrumentation, and display systems is presented. Expected changes include the shift toward more supervisory tasks, development of intervention strategies, and reallocation of function between human and machine. Results are reported in terms of the scope of new technology, human performance issues, and crews experience with digital control systems in a variety of industries petrochemical and aerospace. Plans to conduct a limited Probabilistic Risk Assessment/Human Reliability Assessment (PRA/HRA) comparison between a conventional NUREG-1150 series plant and that same plant retrofit with distributed control and advanced instrumentation and display are also presented. Changes needed to supplement existing HRA modeling methods and quantification techniques are discussed.

  9. Reviewing the impact of advanced control room technology

    SciTech Connect

    Wilhelmsen, C.A.; Gertman, D.I.; Ostrom, L.T.; Nelson, W.R.; Galyean, W.J.; Byers, J.C.

    1992-01-01

    Progress to date on assessing the nature of the expected changes in human performance and risk associated with the introduction of digital control, instrumentation, and display systems is presented. Expected changes include the shift toward more supervisory tasks, development of intervention strategies, and reallocation of function between human and machine. Results are reported in terms of the scope of new technology, human performance issues, and crews experience with digital control systems in a variety of industries petrochemical and aerospace. Plans to conduct a limited Probabilistic Risk Assessment/Human Reliability Assessment (PRA/HRA) comparison between a conventional NUREG-1150 series plant and that same plant retrofit with distributed control and advanced instrumentation and display are also presented. Changes needed to supplement existing HRA modeling methods and quantification techniques are discussed.

  10. Status and design of the Advanced Photon Source control system

    SciTech Connect

    McDowell, W.; Knott, M.; Lenkszus, F.; Kraimer, M.; Arnold, N.; Daly, R.

    1993-06-01

    This paper presents the current status of the Advanced Photon Source (APS) control system. It will discuss the design decisions which led us to use industrial standards and collaborations with other laboratories to develop the APS control system. The system uses high performance graphic workstations and the X-windows Graphical User Interface (GUI) at the operator interface level. It connects to VME/VXI-based microprocessors at the field level using TCP/IP protocols over high performance networks. This strategy assures the flexibility and expansibility of the control system. A defined interface between the system components will allow the system to evolve with the direct addition of future, improved equipment and new capabilities.

  11. Status and design of the Advanced Photon Source control system

    SciTech Connect

    McDowell, W.; Knott, M.; Lenkszus, F.; Kraimer, M.; Arnold, N.; Daly, R.

    1993-01-01

    This paper presents the current status of the Advanced Photon Source (APS) control system. It will discuss the design decisions which led us to use industrial standards and collaborations with other laboratories to develop the APS control system. The system uses high performance graphic workstations and the X-windows Graphical User Interface (GUI) at the operator interface level. It connects to VME/VXI-based microprocessors at the field level using TCP/IP protocols over high performance networks. This strategy assures the flexibility and expansibility of the control system. A defined interface between the system components will allow the system to evolve with the direct addition of future, improved equipment and new capabilities.

  12. Control theory based airfoil design using the Euler equations

    NASA Technical Reports Server (NTRS)

    Jameson, Antony; Reuther, James

    1994-01-01

    This paper describes the implementation of optimization techniques based on control theory for airfoil design. In our previous work it was shown that control theory could be employed to devise effective optimization procedures for two-dimensional profiles by using the potential flow equation with either a conformal mapping or a general coordinate system. The goal of our present work is to extend the development to treat the Euler equations in two-dimensions by procedures that can readily be generalized to treat complex shapes in three-dimensions. Therefore, we have developed methods which can address airfoil design through either an analytic mapping or an arbitrary grid perturbation method applied to a finite volume discretization of the Euler equations. Here the control law serves to provide computationally inexpensive gradient information to a standard numerical optimization method. Results are presented for both the inverse problem and drag minimization problem.

  13. An application of artificial intelligence theory to reconfigurable flight control

    NASA Technical Reports Server (NTRS)

    Handelman, David A.

    1987-01-01

    Artificial intelligence techniques were used along with statistical hpyothesis testing and modern control theory, to help the pilot cope with the issues of information, knowledge, and capability in the event of a failure. An intelligent flight control system is being developed which utilizes knowledge of cause and effect relationships between all aircraft components. It will screen the information available to the pilots, supplement his knowledge, and most importantly, utilize the remaining flight capability of the aircraft following a failure. The list of failure types the control system will accommodate includes sensor failures, actuator failures, and structural failures.

  14. Internal Models in Sensorimotor Integration: Perspectives from Adaptive Control Theory

    PubMed Central

    Tin, Chung; Poon, Chi-Sang

    2007-01-01

    Internal model and adaptive control are empirical and mathematical paradigms that have evolved separately to describe learning control processes in brain systems and engineering systems, respectively. This paper presents a comprehensive appraisal of the correlation between these paradigms with a view to forging a unified theoretical framework that may benefit both disciplines. It is suggested that the classic equilibrium-point theory of impedance control of arm movement is analogous to continuous gain-scheduling or high-gain adaptive control within or across movement trials, respectively, and that the recently proposed inverse internal model is akin to adaptive sliding control originally for robotic manipulator applications. Modular internal models architecture for multiple motor tasks is a form of multi-model adaptive control. Stochastic methods such as generalized predictive control, reinforcement learning, Bayesian learning and Hebbian feedback covariance learning are reviewed and their possible relevance to motor control is discussed. Possible applicability of Luenberger observer and extended Kalman filter to state estimation problems such as sensorimotor prediction or the resolution of vestibular sensory ambiguity is also discussed. The important role played by vestibular system identification in postural control suggests an indirect adaptive control scheme whereby system states or parameters are explicitly estimated prior to the implementation of control. This interdisciplinary framework should facilitate the experimental elucidation of the mechanisms of internal model in sensorimotor systems and the reverse engineering of such neural mechanisms into novel brain-inspired adaptive control paradigms in future. PMID:16135881

  15. Management of redundancy in flight control systems using optimal decision theory

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The problem of using redundancy that exists between dissimilar systems in aircraft flight control is addressed. That is, using the redundancy that exists between a rate gyro and an accelerometer--devices that have dissimilar outputs which are related only through the dynamics of the aircraft motion. Management of this type of redundancy requires advanced logic so that the system can monitor failure status and can reconfigure itself in the event of one or more failures. An optimal decision theory was tutorially developed for the management of sensor redundancy and the theory is applied to two aircraft examples. The first example is the space shuttle and the second is a highly maneuvering high performance aircraft--the F8-C. The examples illustrate the redundancy management design process and the performance of the algorithms presented in failure detection and control law reconfiguration.

  16. The Advancement of Family Therapy Theory Based on the Science of Self-Organizing Complex Systems.

    NASA Astrophysics Data System (ADS)

    Ramsey-Kemper, Valerie Ann

    1995-01-01

    Problem. The purpose of this study was to review the literature which presents the latest advancements in the field of family therapy theory. Since such advancement has relied on the scientific developments in the study of autopoietic self-organizing complex systems, then the review began with an historical overview of the development of these natural scientific concepts. The study then examined how the latest scientific concepts have been integrated with family therapy practice. The document is built on the theory that individuals are living, complex, self-organizing, autopoietic systems. When individual systems interact with other individual systems (such as in family interaction, or in interaction between therapist and client), then a third system emerges, which is the relationship. It is through interaction in the relationship that transformation of an individual system can occur. Method. The historical antecedents of the field of family therapy were outlined. It was demonstrated, via literature review, that the field of family therapy has traditionally paralleled developments in the hard sciences. Further, it was demonstrated via literature review that the newest understandings of the development of individuals, family systems, and therapeutic systems also parallel recent natural science developments, namely those developments based on the science of self-organizing complex systems. Outcome. The results of the study are twofold. First, the study articulates an expanded theory of the therapist, individual, and family as autopoietic self-organizing complex systems. Second, the study provides an expanded hypothesis which concerns recommendations for future research which will further advance the latest theories of family therapy. More precisely, the expanded hypothesis suggests that qualitative research, rather than quantitative research, is the method of choice for studying the effectiveness of phenomenological therapy.

  17. Advanced statistical process control: controlling sub-0.18-μm lithography and other processes

    NASA Astrophysics Data System (ADS)

    Zeidler, Amit; Veenstra, Klaas-Jelle; Zavecz, Terrence E.

    2001-08-01

    Feed-forward, as a method to control the Lithography process for Critical Dimensions and Overlay, is well known in the semiconductors industry. However, the control provided by simple averaging feed-forward methodologies is not sufficient to support the complexity of a sub-0.18micrometers lithography process. Also, simple feed-forward techniques are not applicable for logics and ASIC production due to many different products, lithography chemistry combinations and the short memory of the averaging method. In the semiconductors industry, feed-forward control applications are generally called APC, Advanced Process Control applications. Today, there are as many APC methods as the number of engineers involved. To meet the stringent requirements of 0.18 micrometers production, we selected a method that is described in SPIE 3998-48 (March 2000) by Terrence Zavecz and Rene Blanquies from Yield Dynamics Inc. This method is called PPC, Predictive Process Control, and employs a methodology of collecting measurement results and the modeled bias attributes of expose tools, reticles and the incoming process in a signatures database. With PPC, before each lot exposure, the signatures of the lithography tool, the reticle and the incoming process are used to predict the setup of the lot process and the expected lot results. Benefits derived from such an implementation are very clear; there is no limitation of the number of products or lithography-chemistry combinations and the technique avoids the short memory of conventional APC techniques. ... and what's next? (Rob Morton, Philips assignee to International Sematech). The next part of the paper will try to answer this question. Observing that CMP and metal deposition significantly influence CD's and overlay results, and even Contact Etch can have a significant influence on Metal 5 overlay, we developed a more general PPC for lithography. Starting with the existing lithography PPC applications database, the authors extended the

  18. Advanced Transport Operating System (ATOPS) control display unit software description

    NASA Technical Reports Server (NTRS)

    Slominski, Christopher J.; Parks, Mark A.; Debure, Kelly R.; Heaphy, William J.

    1992-01-01

    The software created for the Control Display Units (CDUs), used for the Advanced Transport Operating Systems (ATOPS) project, on the Transport Systems Research Vehicle (TSRV) is described. Module descriptions are presented in a standardized format which contains module purpose, calling sequence, a detailed description, and global references. The global reference section includes subroutines, functions, and common variables referenced by a particular module. The CDUs, one for the pilot and one for the copilot, are used for flight management purposes. Operations performed with the CDU affects the aircraft's guidance, navigation, and display software.

  19. Coal surface control for advanced fine coal flotation

    SciTech Connect

    Fuerstenau, D.W.; Hanson, J.S.; Diao, J.; Harris, G.H.; De, A.; Sotillo, F. ); Somasundaran, P.; Harris, C.C.; Vasudevan, T.; Liu, D.; Li, C. ); Hu, W.; Zou, Y.; Chen, W. ); Choudhry, V.; Shea, S.; Ghosh, A.; Sehgal, R. )

    1992-03-01

    The initial goal of the research project was to develop methods of coal surface control in advanced froth flotation to achieve 90% pyritic sulfur rejection, while operating at Btu recoveries above 90% based on run-of-mine quality coal. Moreover, the technology is to concomitantly reduce the ash content significantly (to six percent or less) to provide a high-quality fuel to the boiler (ash removal also increases Btu content, which in turn decreases a coal's emission potential in terms of lbs SO{sub 2}/million Btu). (VC)

  20. New virtual laboratories presenting advanced motion control concepts

    NASA Astrophysics Data System (ADS)

    Goubej, Martin; Krejčí, Alois; Reitinger, Jan

    2015-11-01

    The paper deals with development of software framework for rapid generation of remote virtual laboratories. Client-server architecture is chosen in order to employ real-time simulation core which is running on a dedicated server. Ordinary web browser is used as a final renderer to achieve hardware independent solution which can be run on different target platforms including laptops, tablets or mobile phones. The provided toolchain allows automatic generation of the virtual laboratory source code from the configuration file created in the open- source Inkscape graphic editor. Three virtual laboratories presenting advanced motion control algorithms have been developed showing the applicability of the proposed approach.

  1. SECOND GENERATION ADVANCED REBURNING FOR HIGH EFFICIENCY NOx CONTROL

    SciTech Connect

    1998-07-30

    This project is designed to develop a family of novel NO{sub x} control technologies, called Second Generation Advanced Reburning which has the potential to achieve 90+% NO{sub x} control in coal fired boilers at a significantly lower cost than SCR. The third reporting period in Phase II (April 1--June 30, 1998) included experimental activities at pilot scale and comparison of the results with full-scale data. The pilot scale tests were performed with the objective of simulating furnace conditions of ongoing full-scale tests at the Greenidge boiler No. 6 owned and operated by NYSEG and defining the processes controlling AR performance to subsequently improve the performance. The tests were conducted in EER' s Boiler Simulator Facility. The main fuel pulsing system was used at the BSF to control the degree of unmixedness, thus providing control over furnace gas O{sub 2} and CO concentrations. Results on AR-Lean, presented in the previous quarterly report, were compared with full-scale data. Performance of reburn+SNCR was tested to predict NO{sub x} control at Greenidge. The results of the BSF reburn+SNCR simulation tests demonstrated that there are synergistic advantages of using these two technologies in series. In particular, injection of overfire air provides additional mixing that reduces negative effects on AR performance at the temperature regime of the Greenidge boiler.

  2. Indicator system for advanced nuclear plant control complex

    DOEpatents

    Scarola, Kenneth; Jamison, David S.; Manazir, Richard M.; Rescorl, Robert L.; Harmon, Daryl L.

    1993-01-01

    An advanced control room complex for a nuclear power plant, including a discrete indicator and alarm system (72) which is nuclear qualified for rapid response to changes in plant parameters and a component control system (64) which together provide a discrete monitoring and control capability at a panel (14-22, 26, 28) in the control room (10). A separate data processing system (70), which need not be nuclear qualified, provides integrated and overview information to the control room and to each panel, through CRTs (84) and a large, overhead integrated process status overview board (24). The discrete indicator and alarm system (72) and the data processing system (70) receive inputs from common plant sensors and validate the sensor outputs to arrive at a representative value of the parameter for use by the operator during both normal and accident conditions, thereby avoiding the need for him to assimilate data from each sensor individually. The integrated process status board (24) is at the apex of an information hierarchy that extends through four levels and provides access at each panel to the full display hierarchy. The control room panels are preferably of a modular construction, permitting the definition of inputs and outputs, the man machine interface, and the plant specific algorithms, to proceed in parallel with the fabrication of the panels, the installation of the equipment and the generic testing thereof.

  3. Evaluation of advanced displays for engine monitoring and control

    NASA Technical Reports Server (NTRS)

    Summers, L. G.

    1993-01-01

    The relative effectiveness of two advanced display concepts for monitoring engine performance for commercial transport aircraft was studied. The concepts were the Engine Monitoring and Control System (EMACS) display developed by NASA Langley and a display by exception design. Both of these concepts were based on the philosophy of providing information that is directly related to the pilot's task. Both concepts used a normalized thrust display. In addition, EMACS used column deviation indicators; i.e., the difference between the actual parameter value and the value predicted by an engine model, for engine health monitoring; while the Display by Exception displayed the engine parameters if the automated system detected a difference between the actual and the predicted values. The results showed that the advanced display concepts had shorter detection and response times. There were no differences in any of the results between manual and auto throttles. There were no effects upon perceived workload or performance on the primary flight task. The majority of pilots preferred the advanced displays and thought they were operationally acceptable. Certification of these concepts depends on the validation of the engine model. Recommendations are made to improve both the EMACS and the display by exception display formats.

  4. Mercury Control With The Advanced Hybrid Paticulate Collector

    SciTech Connect

    Stanley J. Miller; Ye Zhuang; Jay Almlie

    2004-09-30

    This project was awarded under U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) Program Solicitation DE-PS26-00NT40769 and specifically addresses Technical Topical Area 4 - Testing Novel and Less Mature Control Technologies on Actual Flue Gas at the Pilot Scale. The project team included the Energy & Environmental Research Center (EERC) as the main contractor; W.L. Gore & Associates, Inc., as a technical and financial partner; and the Big Stone Plant operated by Otter Tail Power Company, host for the field-testing portion of the research. Since 1995, DOE has supported development of a new concept in particulate control called the advanced hybrid particulate collector (AHPC). The AHPC has been licensed to W.L. Gore and Associates, Inc., and is marketed as the Advanced Hybrid{trademark} filter by Gore. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in a unique configuration, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and it solves the problem of reentrainment and re-collection of dust in conventional baghouses. The AHPC also appears to have unique advantages for mercury control over baghouses or ESPs as an excellent gas-solid contactor. The objective of the original 5-task project was to demonstrate 90% total mercury control in the AHPC at a lower cost than current mercury control estimates. The approach included bench-scale batch tests, larger-scale pilot testing with real flue gas on a coal-fired combustion system, and field demonstration at the 2.5-MW scale at a utility power plant to prove scale-up and demonstrate longer-term mercury control. The scope of work was modified to include an additional sixth task, initiated in April 2003. The objective of this task

  5. Mercury Control With The Advanced Hybrid Particulate Collector

    SciTech Connect

    Stanley J. Miller; Ye Zhuang; Jay C. Almlie

    2004-12-31

    This project was awarded under U.S. Department of Energy (DOE) National Energy Technology Laboratory Program Solicitation DE-FC26-01NT41184 and specifically addresses Technical Topical Area 4 - Testing Novel and Less Mature Control Technologies on Actual Flue Gas at the Pilot Scale. The project team included the Energy & Environmental Research Center as the main contractor; W.L. Gore & Associates, Inc., as a technical and financial partner; and the Big Stone Plant operated by Otter Tail Power Company, host for the field-testing portion of the research. Since 1995, DOE has supported development of a new concept in particulate control called the advanced hybrid particulate collector (AHPC). The AHPC has been licensed to W.L. Gore and Associates, Inc., and is marketed as the Advanced Hybrid{trademark} filter by Gore. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in a unique configuration, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and it solves the problem of reentrainment and re-collection of dust in conventional baghouses. The AHPC also appears to have unique advantages for mercury control over baghouses or ESPs as an excellent gas--solid contactor. The objective of the original five-task project was to demonstrate 90% total mercury control in the AHPC at a lower cost than current mercury control estimates. The approach included benchscale batch tests, larger-scale pilot testing with real flue gas on a coal-fired combustion system, and field demonstration at the 2.5-MW scale at a utility power plant to prove scale-up and demonstrate longer-term mercury control. The scope of work was modified to include an additional sixth task, initiated in April 2003. The objective of this task was to

  6. Progress in Implementing and Testing State-Space Controls for the Controls Advanced Research Turbine: Preprint

    SciTech Connect

    Wright, A. D.; Fingersh, L. J.; Stol, K. A.

    2004-12-01

    Designing wind turbines with maximum energy production and longevity for minimal cost is a major goal of the federal wind program and the wind industry. Control can improve the performance of wind turbines by enhancing energy capture and reducing dynamic loads. At the National Renewable Energy Laboratory (NREL) we are designing state-space control algorithms for turbine speed regulation and load reduction and testing them on the Controls Advanced Research Turbine (CART). The CART is a test-bed especially designed to test advanced control algorithms on a two-bladed teetering hub upwind turbine. In this paper we briefly describe the design of control systems to regulate turbine speed in region 3 for the CART. These controls use rotor collective pitch to regulate speed and also enhance damping in the 1st drive-train torsion, 1st rotor symmetric flap mode, and the 1st tower fore-aft mode. We designed these controls using linear optimal control techniques using state estimation based on limited turbine measurements such as generator speed and tower fore-aft bending moment. In this paper, we describe the issues and steps involved with implementing and testing these controls on the CART, and we show simulated tests to quantify controller performance. We then present preliminary results after implementing and testing these controls on the CART. We compare results from these controls to field test results from a baseline Proportional Integral control system. Finally we report conclusions to this work and outline future studies.

  7. Intelligent control based on fuzzy logic and neural net theory

    NASA Technical Reports Server (NTRS)

    Lee, Chuen-Chien

    1991-01-01

    In the conception and design of intelligent systems, one promising direction involves the use of fuzzy logic and neural network theory to enhance such systems' capability to learn from experience and adapt to changes in an environment of uncertainty and imprecision. Here, an intelligent control scheme is explored by integrating these multidisciplinary techniques. A self-learning system is proposed as an intelligent controller for dynamical processes, employing a control policy which evolves and improves automatically. One key component of the intelligent system is a fuzzy logic-based system which emulates human decision making behavior. It is shown that the system can solve a fairly difficult control learning problem. Simulation results demonstrate that improved learning performance can be achieved in relation to previously described systems employing bang-bang control. The proposed system is relatively insensitive to variations in the parameters of the system environment.

  8. Development of electrical feedback controlled heat pipes and the advanced thermal control flight experiment

    NASA Technical Reports Server (NTRS)

    Bienert, W. B.

    1974-01-01

    The development and characteristics of electrical feedback controlled heat pipes (FCHP) are discussed. An analytical model was produced to describe the performance of the FCHP under steady state and transient conditions. An advanced thermal control flight experiment was designed to demonstrate the performance of the thermal control component in a space environment. The thermal control equipment was evaluated on the ATS-F satellite to provide performance data for the components and to act as a thermal control system which can be used to provide temperature stability of spacecraft components in future applications.

  9. Advanced Thermo-Adsorptive Battery: Advanced Thermo-Adsorptive Battery Climate Control System

    SciTech Connect

    2011-12-31

    HEATS Project: MIT is developing a low-cost, compact, high-capacity, advanced thermoadsorptive battery (ATB) for effective climate control of EVs. The ATB provides both heating and cooling by taking advantage of the materials’ ability to adsorb a significant amount of water. This efficient battery system design could offer up as much as a 30% increase in driving range compared to current EV climate control technology. The ATB provides high-capacity thermal storage with little-to-no electrical power consumption. The ATB is also looking to explore the possibility of shifting peak electricity loads for cooling and heating in a variety of other applications, including commercial and residential buildings, data centers, and telecom facilities.

  10. A system concept for an advanced vehicle control system

    SciTech Connect

    Mackey, D.E.; Mackey, W.F. Jr.; Mackey, W.F.

    1996-12-01

    This paper explores a system concept for an Advanced Vehicle Control System (AVCS). The progression of highway design and construction has resulted from an evolution of technologies, inventions, organizational creations, and legislative acts supporting the development of a national interstate transportation system. Until now, highway design and construction has been the domain of civil engineers concerned with highway structures, materials loading, traffic patterns, and supporting facilities. However, the growing need for intelligent vehicle-highway systems (IVHS) requires that traditional civil engineering disciplines be integrated with computers, communications, and eventually fully automated vehicles. This paper`s thesis suggests that the complex highway transportation of the late 20th century and the 21st century can benefit from the collaboration of systems engineers and civil engineers. This paper identifies and prototypes an AVCS concept with roadside computers controlling the lateral and longitudinal movements of a vehicle.

  11. Second Generation Advanced Reburning for High Efficiency NOx Control

    SciTech Connect

    Vladimir M. Zamansky; Vitali V. Lissianski

    1999-12-31

    This project is designed to develop a family of novel NO{sub x} control technologies, called Second Generation Advanced Reburning (SGAR) which has the potential to achieve 90+ NO{sub x} control in coal fired boilers at a significantly lower cost than Selective Catalytic Reduction. The ninth reporting period in Phase II (October 1-December 31, 1999) included preparation of the 10 x 10{sup 6} Btu/hr Tower Furnace for tests and setting the SGAR model to predict process performance under Tower Furnace conditions. Based on results of previous work, a paper has been prepared and submitted for the presentation at the 28 Symposium (International) on Combustion to be held at the University of Edinburgh, Scotland.

  12. Advanced optical and thermal technologies for aperture control

    SciTech Connect

    Selkowitz, S.E.; Lampert, C.M.; Rubin, M.

    1982-09-01

    Control of heat transfer and radiant energy flow through building apertures is essential for maximizing thermal and daylighting benefits and minimizing undesired heating and cooling loads. Architectural solutions based on current technology generally add devices such as louvers, shutters, shades, or blinds to the glazing system. The objectives and initial accomplishments of a research program the goal of which is to identify and evaluate advanced optical and thermal technologies for controlling aperture energy flows, thus reducing building energy requirements are outlined. Activities are described in four program areas: (1) low-conductance, high-transmittance glazing materials (e.g., heat mirrors, aerogels); (2) optical switching materials (e.g., electrochromic, photochromic); (3) selective transmitters; and (4) daylight enhancement techniques.

  13. Advanced optical and thermal technologies for aperture control

    SciTech Connect

    Selkowitz, S.E.; Lampert, C.M.; Rubin, M.

    1983-11-01

    Control of heat transfer and radiant energy flow through building apertures is essential for maximizing thermal and daylighting benefits and minimizing undesired heating and cooling loads. Architectural solutions based on current technology generally add devices such as louvers, shutters, shades, or blinds to the glazing system. The objectives and initial accomplishments of a research program are outlined, the goal of which is to identify and evaluate advanced optical and thermal technologies for controlling aperture energy flows, thus reducing building energy requirements. Activities in four program areas are described: (1) low-conductance, high-transmittance glazing materials (e.g., heat mirrors, aerogels) (2) optical switching materials (e.g., electrochromic, photochromic) (3) selective transmitters and (4) daylight enhancement techniques.

  14. A Simplified Theory of Coupled Oscillator Array Phase Control

    NASA Technical Reports Server (NTRS)

    Pogorzelski, R. J.; York, R. A.

    1997-01-01

    Linear and planar arrays of coupled oscillators have been proposed as means of achieving high power rf sources through coherent spatial power combining. In such - applications, a uniform phase distribution over the aperture is desired. However, it has been shown that by detuning some of the oscillators away from the oscillation frequency of the ensemble of oscillators, one may achieve other useful aperture phase distributions. Notable among these are linear phase distributions resulting in steering of the output rf beam away from the broadside direction. The theory describing the operation of such arrays of coupled oscillators is quite complicated since the phenomena involved are inherently nonlinear. This has made it difficult to develop an intuitive understanding of the impact of oscillator tuning on phase control and has thus impeded practical application. In this work a simpl!fied theory is developed which facilitates intuitive understanding by establishing an analog of the phase control problem in terms of electrostatics.

  15. MERCURY CONTROL WITH THE ADVANCED HYBRID PARTICULATE COLLECTOR

    SciTech Connect

    Stanley J. Miller; Ye Zhuang; Michelle R. Olderbak

    2003-03-01

    This project was awarded under U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) Program Solicitation DE-PS26-00NT40769 and specifically addresses Technical Topical Area 4--Testing Novel and Less Mature Control Technologies on Actual Flue Gas at the Pilot Scale. The project team includes the Energy & Environmental Research Center (EERC) as the main contractor; W.L. Gore & Associates, Inc., as a technical and financial partner; and the Big Stone Plant operated by Otter Tail Power Company, host for the field testing portion of the research. Since 1995, DOE has supported development of a new concept in particulate control called the advanced hybrid particulate collector (AHPC). The AHPC has been licensed to W.L. Gore & Associates, Inc., and is now marketed as the Advanced Hybrid{trademark} filter by Gore. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in a unique configuration, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and it solves the problem of reentrainment and re-collection of dust in conventional baghouses. The AHPC appears to have unique advantages for mercury control over baghouses or ESPs as an excellent gas-solid contactor. The objective of the three-task project is to demonstrate 90% total mercury control in the AHPC at a lower cost than current mercury control estimates. The approach includes bench-scale batch testing that ties the new work to previous results and links results with larger-scale pilot testing with real flue gas on a coal-fired combustion system, pilot-scale testing on a coal-fired combustion system with both a pulse-jet baghouse and an AHPC to prove or disprove the research hypotheses, and field demonstration pilot-scale testing at a

  16. MERCURY CONTROL WITH THE ADVANCED HYBRID PARTICULATE COLLECTOR

    SciTech Connect

    Ye Zhuang; Stanley J. Miller; Steven A. Benson; Michelle R. Olderbak

    2003-08-01

    This project was awarded under U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) Program Solicitation DE-PS26-00NT40769 and specifically addresses Technical Topical Area 4-Testing Novel and Less Mature Control Technologies on Actual Flue Gas at the Pilot Scale. The project team includes the Energy & Environmental Research Center (EERC) as the main contractor; W.L. Gore & Associates, Inc., as a technical and financial partner; and the Big Stone Plant operated by Otter Tail Power Company, host for the field-testing portion of the research. Since 1995, DOE has supported development of a new concept in particulate control called the advanced hybrid particulate collector (AHPC). The AHPC has been licensed to W.L. Gore & Associates, Inc., and is now marketed as the ''Advanced Hybrid''{trademark} filter by Gore. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in a unique configuration, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The AHPC provides ultra-high collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and it solves the problem of reentrainment and re-collection of dust in conventional baghouses. The AHPC appears to have unique advantages for mercury control over baghouses or ESPs as an excellent gas-solid contactor. The objective of the three-task project is to demonstrate 90% total mercury control in the AHPC at a lower cost than current mercury control estimates. The approach includes bench-scale batch testing that ties the new work to previous results and links results with larger-scale pilot testing with real flue gas on a coal-fired combustion system, pilot-scale testing on a coal-fired combustion system with both a pulse-jet baghouse and an AHPC to prove or disprove the research hypotheses, and field demonstration pilot-scale testing at a

  17. MERCURY CONTROL WITH THE ADVANCED HYBRID PARTICULATE COLLECTOR

    SciTech Connect

    Stanley J. Miller; Ye Zhuang; Michelle R. Olderbak

    2002-11-01

    This project was awarded under U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) Program Solicitation DE-PS26-00NT40769 and specifically addresses Technical Topical Area 4-Testing Novel and Less Mature Control Technologies on Actual Flue Gas at the Pilot Scale. The project team includes the Energy & Environmental Research Center (EERC) as the main contractor; W.L. Gore & Associates, Inc., as a technical and financial partner; and the Big Stone Power Plant operated by Otter Tail Power Company, host for the field-testing portion of the research. Since 1995, DOE has supported development of a new concept in particulate control called the advanced hybrid particulate collector (AHPC). The AHPC has been licensed to W.L. Gore & Associates, Inc., and is now marketed as the ADVANCED HYBRID{trademark} Filter by Gore. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in a unique configuration, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and it solves the problem of reentrainment and re-collection of dust in conventional baghouses. The AHPC appears to have unique advantages for mercury control over baghouses or ESPs as an excellent gas-solid contactor. The objective of the three-task project is to demonstrate 90% total mercury control in the AHPC at a lower cost than current mercury control estimates. The approach includes bench-scale batch testing that ties the new work to previous results and links results with larger-scale pilot testing with real flue gas on a coal-fired combustion system, pilot-scale testing on a coal-fired combustion system with both a pulse-jet baghouse and an AHPC to prove or disprove the research hypotheses, and field demonstration pilot-scale testing at a

  18. Mercuty Control With The Advanced Hybrid Particulate Collector

    SciTech Connect

    Ye Zhuang; Stanley J. Miller; Michelle R. Olderbak

    2003-03-31

    This project was awarded under U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) Program Solicitation DE-PS26-00NT40769 and specifically addresses Technical Topical Area 4 - Testing Novel and Less Mature Control Technologies on Actual Flue Gas at the Pilot Scale. The project team includes the Energy & Environmental Research Center (EERC) as the main contractor; W.L. Gore & Associates, Inc., as a technical and financial partner; and the Big Stone Plant operated by Otter Tail Power Company, host for the field testing portion of the research. Since 1995, DOE has supported development of a new concept in particulate control called the advanced hybrid particulate collector (AHPC). The AHPC has been licensed to W.L. Gore and Associates, Inc., and is now marketed as the Advanced Hybrid{trademark} filter by Gore. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in a unique configuration, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and it solves the problem of reentrainment and re-collection of dust in conventional baghouses. The AHPC appears to have unique advantages for mercury control over baghouses or ESPs as an excellent gas-solid contactor. The objective of the three-task project is to demonstrate 90% total mercury control in the AHPC at a lower cost than current mercury control estimates. The approach includes bench-scale batch testing that ties the new work to previous results and links results with larger-scale pilot testing with real flue gas on a coal-fired combustion system, pilot-scale testing on a coal-fired combustion system with both a pulse-jet baghouse and an AHPC to prove or disprove the research hypotheses, and field demonstration pilot-scale testing at a

  19. An Advanced Tool for Control System Design and Maintenance

    SciTech Connect

    Storm, Joachim; Lohmann, Heinz

    2006-07-01

    The detailed engineering for control systems is usually supported by CAD Tools creating the relevant logic diagrams including software parameters and signal cross references. However at this stage of the design an early V and V process for checking out the functional correctness of the design is not available. The article describes the scope and capabilities of an advanced control system design tool which has the embedded capability of a stand-alone simulation of complex logic structures. The tool provides the following features for constructing logic diagrams for control systems: - Drag and Drop construction of logic diagrams using a predefined symbol sets; - Cross reference facility; - Data extraction facility; - Stand-alone simulation for Logic Diagrams featuring: On the fly changes, signal line animation, value boxes and mini trends etc. - Creation and on-line animation of Compound Objects (Handler); - Code Generation Facility for Simulation; - Code Generation Facility for several control systems. The results of the integrated simulation based V and V process can be used further for initial control system configuration and life cycle management as well as for Engineering Test Bed applications and finally in full Scope Replica Simulators for Operator Training. (authors)

  20. A feedback control for the advanced launch system

    NASA Technical Reports Server (NTRS)

    Seywald, Hans; Cliff, Eugene M.

    1991-01-01

    A robust feedback algorithm is presented for a near-minimum-fuel ascent of a two-stage launch vehicle operating in the equatorial plane. The development of the algorithm is based on the ideas of neighboring optimal control and can be derived into three phases. In phase 1, the formalism of optimal control is employed to calculate fuel-optimal ascent trajectories for a simple point-mass model. In phase 2, these trajectories are used to numerically calculate gain functions of time for the control(s), the total flight time, and possibly, for other variables of interest. In phase 3, these gains are used to determine feedback expressions for the controls associated with a more realistic model of a launch vehicle. With the Advanced Launch System in mind, all calculations are performed on a two-stage vehicle with fixed thrust history, but this restriction is by no means important for the approach taken. Performance and robustness of the algorithm is found to be excellent.

  1. New advanced control methods for doubly salient permanent magnet motor

    SciTech Connect

    Blaabjerg, F.; Christensen, L.; Rasmussen, P.O.; Oestergaard, L.; Pedersen, P.

    1995-12-31

    High performance and high efficiency in adjustable speed drives are needed and new motor constructions are world wide investigated and analyzed. This paper deals with advanced control of a recently developed Doubly Salient Permanent Magnet (DSPM) motor. The construction of the DSPM motor is shown and a dynamical model of the motor is used for simulations. As supply to the DSPM motor, a power converter with a split capacitor is used to reduce the number of devices, and a basic control method for this converter is explained. This control method will cause an unequal voltage distribution across the capacitors because the motor is asymmetrical and a decrease in efficiency and a poorer dynamic performance are the results. To minimize the problems with the unequal load of the capacitors in the converter, a new charge control strategy is developed. The efficiency of the motor can also be improved by using a power minimizing scheme based on changing the turn-on and turn-off angles of the current. The two different strategies are implemented in an adjustable-speed drive, and it is concluded that both control strategies improve the performance of the drive.

  2. Modeling of ICRF Internal Transport Barrier Control for Advanced Tokamaks

    NASA Astrophysics Data System (ADS)

    Sund, R. S.; Scharer, J. E.

    1998-11-01

    We present an analysis of TFTR ICRF current drive experiments carried out by Majeski et al.(R. Majeski, J. Rodgers, G. Schilling, C. Phillips, J. Hosea and the TFTR Group, private communication.) The influence of deuterium, tritium, minority specie, electron and alpha concentrations, temperatures and beam fractions are considered for the two-ion mode conversion current drive experiments. Direct comparison with experimental data is carried out by means of a nonlocal large gyroradius ICRF code(O. Sauter, Ph.D. thesis, Ecole Polytechnique de Lausanne, Switzerland (1992).) which incorporates 1-D plasma profiles. It is found that substantial beam and alpha particle absorption can occur for some cases. Application of ion cyclotron range of frequencies internal transport barrier control requires further examination of fast wave mode conversion and the interaction of ion Bernstein waves with plasmas in advanced tokamaks. The effects of perpendicular and parallel magnetic gradients on the ion, electron, and alpha particle absorption are examined. A viable internal transport barrier control scheme for a reactor grade advanced tokamak will be discussed.

  3. Coal surface control for advanced fine coal flotation

    SciTech Connect

    Fuerstenau, D.W.; Sastry, K.V.S.; Hanson, J.S.; Diao, J.; De, A.; Sotillo, F.; Harris, G. ); Somasundaran, P.; Harris, C.C.; Vasudevan, T.; Liu, D.; Li, C. ); Hu, Weibai; Zou, Y.; Chen, W. ); Choudhry, V.; Sehgal, R.; Ghosh, A. (Praxis Engineers, Inc., Milpitas, CA (United

    1991-07-30

    The primary objective in the scope of this research project is to develop advanced flotation methods for coal cleaning in order to achieve near total pyritic-sulfur removal at 90% Btu recovery, using coal samples procured from three major US coal seams. Concomitantly, the ash content of these coals is to be reduced to 6% or less. Investigation of mechanisms for the control of coal and pyrite surfaces prior to fine coal flotation is the main aspect of the project objectives. The results of this research are to be made available to ICF Kaiser Engineers who are currently working on the Engineering Development of Advanced Flotation under a separate contract with DOE under the Acid Rain Control Initiative program. A second major objective is to investigate factors involved in the progressive weathering and oxidation of coal that had been exposed to varying degrees of weathering, namely, open to the atmosphere, covered and in an argon-inerted'' atmosphere, over a period of twelve months. After regular intervals of weathering, samples of the three base coals (Illinois No. 6, Pittsburgh No. 8 and Upper Freeport PA) were collected and shipped to both the University of Pittsburgh and the University of California at Berkeley for characterization studies of the weathered material. 29 figs., 29 tabs.

  4. Stochastic resonance-a nonlinear control theory interpretation

    NASA Astrophysics Data System (ADS)

    Repperger, D. W.; Farris, K. A.

    2010-07-01

    Stochastic resonance (SR) is an effect that has been known (Benzi, R., Sutera, A., and Vulpiani, A. (1981), 'The Mechanism of Stochastic Resonance', Journal of Physics, A14, L453-L457) for almost three decades and has been extensively studied in biology, statistics, signal processing and in numerous other eclectic areas (Wiesenfeld, K., and Moss, F. (1995), 'Stochastic Resonance and the Benefits of Noise: From Ice Ages to Crayfish and Squids', Nature, 373, 33-36). Herein, a nonlinear control theory analysis is conducted on how to better understand the class of systems that may exhibit the SR effect. Using nonlinear control theory methods, equilibrium points are manipulated to create the SR response (similar to shaping dynamical response in a phase plane). From this approach, a means of synthesising and designing the appropriate class of nonlinear systems is introduced. New types of nonlinear dynamics that demonstrate the SR effects are discovered, which may have utility in control theory as well as in many diverse applications. A numerical simulation illustrates some powerful attributes of these systems.

  5. A Theory of Cheap Control in Embodied Systems

    PubMed Central

    Montúfar, Guido; Ghazi-Zahedi, Keyan; Ay, Nihat

    2015-01-01

    We present a framework for designing cheap control architectures of embodied agents. Our derivation is guided by the classical problem of universal approximation, whereby we explore the possibility of exploiting the agent’s embodiment for a new and more efficient universal approximation of behaviors generated by sensorimotor control. This embodied universal approximation is compared with the classical non-embodied universal approximation. To exemplify our approach, we present a detailed quantitative case study for policy models defined in terms of conditional restricted Boltzmann machines. In contrast to non-embodied universal approximation, which requires an exponential number of parameters, in the embodied setting we are able to generate all possible behaviors with a drastically smaller model, thus obtaining cheap universal approximation. We test and corroborate the theory experimentally with a six-legged walking machine. The experiments indicate that the controller complexity predicted by our theory is close to the minimal sufficient value, which means that the theory has direct practical implications. PMID:26325254

  6. Theory of optical spin control in quantum dot microcavities

    NASA Astrophysics Data System (ADS)

    Smirnov, D. S.; Glazov, M. M.; Ivchenko, E. L.; Lanco, L.

    2015-09-01

    We present a microscopic theory of optical initialization, control, and detection for a single electron spin in a quantum dot embedded into a zero-dimensional microcavity. The strong coupling regime of the trion and the cavity mode is addressed. We demonstrate that efficient spin orientation by a single circularly polarized pulse is possible in relatively weak transverse magnetic fields. The possibilities for spin control by additional circularly polarized pulse are analyzed. Under optimal conditions the Kerr and Faraday rotation angles induced by the spin polarized electron may reach tens of degrees.

  7. Pheromonal control: reconciling physiological mechanism with signalling theory.

    PubMed

    Peso, Marianne; Elgar, Mark A; Barron, Andrew B

    2015-05-01

    Pheromones are intraspecific chemical signals. They can have profound effects on the behaviour and/or physiology of the receiver, and it is still common to hear pheromones described as controlling of the behaviour of the receiver. The discussion of pheromonal control arose initially from a close association between hormones and pheromones in the comparative physiological literature, but the concept of a controlling pheromone is at odds with contemporary signal evolution theory, which predicts that a manipulative pheromonal signal negatively affecting the receiver's fitness should not be stable over evolutionary time. Here we discuss the meaning of pheromonal control, and the ecological circumstances by which it might be supported. We argue that in discussing pheromonal control it is important to differentiate between control applied to the effects of a pheromone on a receiver's physiology (proximate control), and control applied to the effects of a pheromone on a receiver's fitness (ultimate control). Critically, a pheromone signal affecting change in the receiver's behaviour or physiology need not necessarily manipulate the fitness of a receiver. In cases where pheromonal signalling does lead to a reduction in the fitness of the receiver, the signalling system would be stable if the pheromone were an honest signal of a social environment that disadvantages the receiver, and the physiological and behavioural changes observed in the receiver were an adaptive response to the new social circumstances communicated by the pheromone. PMID:24925630

  8. MERCURY CONTROL WITH THE ADVANCED HYBRID PARTICULATE COLLECTOR

    SciTech Connect

    Ye Zhuang; Stanley J. Miller; Grant E. Dunham; Michelle R. Olderbak

    2002-02-01

    Since 1995, DOE has supported development of a new concept in particulate control, called the advanced hybrid particulate collector (AHPC). The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in a unique configuration, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emission with conventional ESPs, and it solves the problem of reentrainment and re-collection of dust in conventional baghouses. The AHPC appears to have unique advantages for mercury control over baghouses or ESPs as an excellent gas-solid contactor. The objective of the three-task project is to demonstrate 90% total mercury control in the AHPC at a lower cost than current mercury control estimates. The approach includes bench-scale batch testing that ties the new work to previous results and links results with larger-scale pilot testing with real flue gas on a coal-fired combustion system, pilot-scale testing on a coal-fired combustion system with both a pulse-jet baghouse and an AHPC to prove or disprove the research hypotheses, and field demonstration pilot-scale testing at a utility power plant to prove scaleup and demonstrate longer-term mercury control. This project, if successful, will demonstrate at the pilot-scale level a technology that would provide a cost-effective technique to accomplish control of mercury emissions and, at the same time, greatly enhance fine particulate collection efficiency. The technology can be used to retrofit systems currently employing inefficient ESP technology as well as for new construction, thereby providing a solution to a large segment of the U.S. utility industry as well as other industries requiring mercury control.

  9. Advanced Issues of Wind Turbine Modelling and Control

    NASA Astrophysics Data System (ADS)

    Simani, Silvio

    2015-11-01

    The motivation for this paper comes from a real need to have an overview about the challenges of modelling and control for very demanding systems, such as wind turbine systems, which require reliability, availability, maintainability, and safety over power conversion efficiency. These issues have begun to stimulate research and development in the wide control community particularly for these installations that need a high degree of “sustainability”. Note that this topic represents a key point mainly for offshore wind turbines with very large rotors, since they are characterised by challenging modelling and control problems, as well as expensive and safety critical maintenance works. In this case, a clear conflict exists between ensuring a high degree of availability and reducing maintenance times, which affect the final energy cost. On the other hand, wind turbines have highly nonlinear dynamics, with a stochastic and uncontrollable driving force as input in the form of wind speed, thus representing an interesting challenge also from the modelling point of view. Suitable control methods can provide a sustainable optimisation of the energy conversion efficiency over wider than normally expected working conditions. Moreover, a proper mathematical description of the wind turbine system should be able to capture the complete behaviour of the process under monitoring, thus providing an important impact on the control design itself. In this way, the control scheme could guarantee prescribed performance, whilst also giving a degree of “tolerance” to possible deviation of characteristic properties or system parameters from standard conditions, if properly included in the wind turbine model itself. The most important developments in advanced controllers for wind turbines are addressed, and open problems in the areas of modelling of wind turbines are also outlined.

  10. Adaptive dynamic programming as a theory of sensorimotor control.

    PubMed

    Jiang, Yu; Jiang, Zhong-Ping

    2014-08-01

    Many characteristics of sensorimotor control can be explained by models based on optimization and optimal control theories. However, most of the previous models assume that the central nervous system has access to the precise knowledge of the sensorimotor system and its interacting environment. This viewpoint is difficult to be justified theoretically and has not been convincingly validated by experiments. To address this problem, this paper presents a new computational mechanism for sensorimotor control from a perspective of adaptive dynamic programming (ADP), which shares some features of reinforcement learning. The ADP-based model for sensorimotor control suggests that a command signal for the human movement is derived directly from the real-time sensory data, without the need to identify the system dynamics. An iterative learning scheme based on the proposed ADP theory is developed, along with rigorous convergence analysis. Interestingly, the computational model as advocated here is able to reproduce the motor learning behavior observed in experiments where a divergent force field or velocity-dependent force field was present. In addition, this modeling strategy provides a clear way to perform stability analysis of the overall system. Hence, we conjecture that human sensorimotor systems use an ADP-type mechanism to control movements and to achieve successful adaptation to uncertainties present in the environment. PMID:24962078

  11. Recent Advances in the Theory and Simulation of Model Colloidal Microphase Formers.

    PubMed

    Zhuang, Yuan; Charbonneau, Patrick

    2016-08-18

    This mini-review synthesizes our understanding of the equilibrium behavior of particle-based models with short-range attractive and long-range repulsive (SALR) interactions. These models, which can form stable periodic microphases, aim to reproduce the essence of colloidal suspensions with competing interparticle interactions. Ordered structures, however, have yet to be obtained in experiments. In order to better understand the hurdles to periodic microphase assembly, marked theoretical and simulation advances have been made over the past few years. Here, we present recent progress in the study of microphases in models with SALR interactions using liquid-state theory and density-functional theory as well as numerical simulations. Combining these various approaches provides a description of periodic microphases, and gives insights into the rich phenomenology of the surrounding disordered regime. Ongoing research directions in the thermodynamics of models with SALR interactions are also presented. PMID:27466702

  12. Advancing the practice of online psychotherapy: An application of Rogers' diffusion of innovations theory.

    PubMed

    Lovejoy, Travis I; Demireva, Petya D; Grayson, Jessica L; McNamara, John R

    2009-03-01

    With the advancements of technology and its increasing use in all spheres of life, clinicians too are faced with the decision of whether to adopt or refrain from adopting certain innovations in their practice. This article discusses the process of adopting clinical innovations within a theoretical framework, namely diffusion of innovations theory (DIT; Rogers, 2003). DIT constructs are applied to the example of online therapy adoption into clinical practice. Nine adoption barriers are identified, including issues of dehumanizing the therapeutic environment, start-up cost and reimbursement, infrastructure and training, licensure and jurisdiction concerns, ethical guidelines, both client and clinician suitability factors, and professional reputation and acceptance within the field. The authors conclude with a theory-based discussion of activities that may help to accelerate the adoption of online therapy among professional psychologists. (PsycINFO Database Record (c) 2010 APA, all rights reserved). PMID:22122574

  13. Advancing the Theory of Nuclear Reactions with Rare Isotopes. From the Laboratory to the Cosmos

    SciTech Connect

    Nunes, Filomena

    2015-06-01

    The mission of the Topical Collaboration on the Theory of Reactions for Unstable iSotopes (TORUS) was to develop new methods to advance nuclear reaction theory for unstable isotopes—particularly the (d,p) reaction in which a deuteron, composed of a proton and a neutron, transfers its neutron to an unstable nucleus. After benchmarking the state-of-the-art theories, the TORUS collaboration found that there were no exact methods to study (d,p) reactions involving heavy targets; the difficulty arising from the long-range nature of the well known, yet subtle, Coulomb force. To overcome this challenge, the TORUS collaboration developed a new theory where the complexity of treating the long-range Coulomb interaction is shifted to the calculation of so-called form-factors. An efficient implementation for the computation of these form factors was a major achievement of the TORUS collaboration. All the new machinery developed are essential ingredients to analyse (d,p) reactions involving heavy nuclei relevant for astrophysics, energy production, and stockpile stewardship.

  14. The Social Structuring of Mental Health over the Adult Life Course: Advancing Theory in the Sociology of Aging

    ERIC Educational Resources Information Center

    Clarke, Philippa; Marshall, Victor; House, James; Lantz, Paula

    2011-01-01

    The sociology of aging draws on a broad array of theoretical perspectives and social theories from several disciplines, but rarely has it developed its own theories or theoretical perspectives. We build on past work to further advance and empirically test a model of mental health framed in terms of structural theorizing and situated within the…

  15. Advanced Flow Control as a Management Tool in the National Airspace System

    NASA Technical Reports Server (NTRS)

    Wugalter, S.

    1974-01-01

    Advanced Flow Control is closely related to Air Traffic Control. Air Traffic Control is the business of the Federal Aviation Administration. To formulate an understanding of advanced flow control and its use as a management tool in the National Airspace System, it becomes necessary to speak somewhat of air traffic control, the role of FAA, and their relationship to advanced flow control. Also, this should dispell forever, any notion that advanced flow control is the inspirational master valve scheme to be used on the Alaskan Oil Pipeline.

  16. A Theory and Model of Conflict Detection in Air Traffic Control: Incorporating Environmental Constraints

    ERIC Educational Resources Information Center

    Loft, Shayne; Bolland, Scott; Humphreys, Michael S.; Neal, Andrew

    2009-01-01

    A performance theory for conflict detection in air traffic control is presented that specifies how controllers adapt decisions to compensate for environmental constraints. This theory is then used as a framework for a model that can fit controller intervention decisions. The performance theory proposes that controllers apply safety margins to…

  17. Advanced information processing system: Hosting of advanced guidance, navigation and control algorithms on AIPS using ASTER

    NASA Technical Reports Server (NTRS)

    Brenner, Richard; Lala, Jaynarayan H.; Nagle, Gail A.; Schor, Andrei; Turkovich, John

    1994-01-01

    This program demonstrated the integration of a number of technologies that can increase the availability and reliability of launch vehicles while lowering costs. Availability is increased with an advanced guidance algorithm that adapts trajectories in real-time. Reliability is increased with fault-tolerant computers and communication protocols. Costs are reduced by automatically generating code and documentation. This program was realized through the cooperative efforts of academia, industry, and government. The NASA-LaRC coordinated the effort, while Draper performed the integration. Georgia Institute of Technology supplied a weak Hamiltonian finite element method for optimal control problems. Martin Marietta used MATLAB to apply this method to a launch vehicle (FENOC). Draper supplied the fault-tolerant computing and software automation technology. The fault-tolerant technology includes sequential and parallel fault-tolerant processors (FTP & FTPP) and authentication protocols (AP) for communication. Fault-tolerant technology was incrementally incorporated. Development culminated with a heterogeneous network of workstations and fault-tolerant computers using AP. Draper's software automation system, ASTER, was used to specify a static guidance system based on FENOC, navigation, flight control (GN&C), models, and the interface to a user interface for mission control. ASTER generated Ada code for GN&C and C code for models. An algebraic transform engine (ATE) was developed to automatically translate MATLAB scripts into ASTER.

  18. Theory of Optimal Phase-Unlocked Pump-Dump Control

    NASA Astrophysics Data System (ADS)

    Yan, Yijing

    1997-04-01

    A novel theory of optimal control via a pair of phase-unlocked pump-dump fields is developed. We first derive a pair of coupled nonlinear control equations for mixed or dissipative quantum systems in the strong response regime. These equations should be solved iteratively, resulting in a locally optimal pair of fields that are however usually too complicated to be realizable. To facilitate this problem, we further develop a hierarchy of reduction and arrive at a variety of simplified control equation pairs. In the weak response regime, we obtain a pair of coupled semi-linear control equations in which the globally optimal pump field at any given pump field, or vice verse, can be evaluated in a non-iterative manor. However, it still requires an iterative solution to the semi-globally optimal pair of pump-dump fields. Further reduction is then devised to consider the pure state control system in the weak response regime. In this case, we derive a generalized eigenequation for the non-iterative solution to the complete set of optimal control field pairs, and further identify the globally optimal one unambiguously. The existence of certain symmetry relation between the pump and dump fields in any optimal pair is also analyzed in the stimulate Raman pumping control configuration and demonstrated numerically.

  19. Advanced launch system trajectory optimization using suboptimal control

    NASA Technical Reports Server (NTRS)

    Shaver, Douglas A.; Hull, David G.

    1993-01-01

    The maximum-final mass trajectory of a proposed configuration of the Advanced Launch System is presented. A model for the two-stage rocket is given; the optimal control problem is formulated as a parameter optimization problem; and the optimal trajectory is computed using a nonlinear programming code called VF02AD. Numerical results are presented for the controls (angle of attack and velocity roll angle) and the states. After the initial rotation, the angle of attack goes to a positive value to keep the trajectory as high as possible, returns to near zero to pass through the transonic regime and satisfy the dynamic pressure constraint, returns to a positive value to keep the trajectory high and to take advantage of minimum drag at positive angle of attack due to aerodynamic shading of the booster, and then rolls off to negative values to satisfy the constraints. Because the engines cannot be throttled, the maximum dynamic pressure occurs at a single point; there is no maximum dynamic pressure subarc. To test approximations for obtaining analytical solutions for guidance, two additional optimal trajectories are computed: one using untrimmed aerodynamics and one using no atmospheric effects except for the dynamic pressure constraint. It is concluded that untrimmed aerodynamics has a negligible effect on the optimal trajectory and that approximate optimal controls should be able to be obtained by treating atmospheric effects as perturbations.

  20. Temperature controlled material irradiation in the advanced test reactor

    SciTech Connect

    Furstenau, R.V.; Ingrahm, F.W.

    1995-12-31

    The Advanced Test Reactor (ATR) is located at the Idaho National Engineering Laboratory (INEL) near Idaho Falls, Idaho, USA and is owned and regulated by the U.S. Department of Energy (US DOE). The ATR is operated for the US DOE by Lockheed Martin Idaho Technologies. In recent years, prime irradiation space in the ATR has been made available for use by customers having irradiation service needs in addition to the reactor`s principal user, the U.S. Naval Nuclear Propulsion Program. To enhance the reactor`s capabilities, the US DOE has initiated the development of an Irradiation Test Vehicle (ITV) capable of providing neutron spectral tailoring and temperature control for up to 28 experiments. The ATR-ITV will have the flexibility to simultaneously support a variety of experiments requiring fast, thermal or mixed spectrum neutron environments. Temperature control is accomplished by varying the thermal conductivity across a gas gap established between the experiment specimen capsule wall and the experiment `in-pile tube (IPT)` inside diameter. Thermal conductivity is adjusted by alternating the control gas mixture ratio of two gases with different thermal conductivities.

  1. Recent advances in the study of gynodioecy: the interface of theory and empiricism

    PubMed Central

    McCauley, David E.; Bailey, Maia F.

    2009-01-01

    Background In this review we report on recent literature concerned with studies of gynodioecy, or the co-occurrence of female and hermaphrodite individuals in natural plant populations. Rather than review this literature in its entirety, our focus is on the interplay between theoretical and empirical approaches to the study of gynodioecy. Scope Five areas of active inquiry are considered. These are the cost of restoration, the influence of population structure on spatial sex-ratio variation, the influence of inbreeding on sex expression, the signature of cyto-nuclear coevolution on the mitochondrial genome, and the consequences of mitochondrial paternal leakage. Conclusions Recent advances in the study of gynodioecy have been made by considering both the ecology of female:hermaphrodite fitness differences and the genetics of sex expression. Indeed theory has guided empiricism and empiricism has guided theory. Future advances will require that some of the methods currently available only for model organisms be applied to a wider range of species. PMID:19515690

  2. HFE safety reviews of advanced nuclear power plant control rooms

    NASA Technical Reports Server (NTRS)

    Ohara, John

    1994-01-01

    Advanced control rooms (ACR's) will utilize human-system interface (HSI) technologies that may have significant implications for plant safety in that they will affect the operator's overall role and means of interacting with the system. The Nuclear Regulatory Commission (NRC) reviews the human factors engineering (HFE) aspects of HSI's to ensure that they are designed to good HFE principles and support performance and reliability in order to protect public health and safety. However, the only available NRC guidance was developed more than ten years ago, and does not adequately address the human performance issues and technology changes associated with ACR's. Accordingly, a new approach to ACR safety reviews was developed based upon the concept of 'convergent validity'. This approach to ACR safety reviews is described.

  3. Advanced methods of microscope control using μManager software

    PubMed Central

    Edelstein, Arthur D.; Tsuchida, Mark A.; Amodaj, Nenad; Pinkard, Henry; Vale, Ronald D.; Stuurman, Nico

    2014-01-01

    μManager is an open-source, cross-platform desktop application, to control a wide variety of motorized microscopes, scientific cameras, stages, illuminators, and other microscope accessories. Since its inception in 2005, μManager has grown to support a wide range of microscopy hardware and is now used by thousands of researchers around the world. The application provides a mature graphical user interface and offers open programming interfaces to facilitate plugins and scripts. Here, we present a guide to using some of the recently added advanced μManager features, including hardware synchronization, simultaneous use of multiple cameras, projection of patterned light onto a specimen, live slide mapping, imaging with multi-well plates, particle localization and tracking, and high-speed imaging. PMID:25606571

  4. Coal surface control for advanced fine coal flotation

    SciTech Connect

    Fuerstenau, D.W.; Sastry, K.V.S.; Hanson, J.S.; Narayanan, K.S.; Herrera-Urbina, R.; Diao, J.; Yin, Y.; Sotillo, F.; Harris, G. ); Hu, Weibei; Zou, Y.; Chen, W. ); Somasundaran, P.; Harris, C.C.; Vasudevan, T.; Xhong, K.; Xiao, L. ); Choudhry, V.; Shea, S.; Ghosh, A.; Sehgal, R. (Praxis Engineers, Inc., Mi

    1990-02-28

    The primary objective of this research project is to develop advanced flotation methods for coal cleaning in order to achieve 90% pyritic sulfur removal at 90% Btu recovery, using coal samples procured from six major US coal seams. Concomitantly, the ash content of these coals is to be reduced to 6% or less. Investigation of mechanisms for the control of coal and pyrite surfaces prior to fine coal flotation is an important aspect of the project objectives. The effect of the following additives on flotation response was investigated. These include methanol lethanol, butylbenzaldehyde, glyoxal and several monomers. A second major objective is to investigate factors involved in the progressive weathering and oxidation of coal that had been stored in three storage modes, namely, open, covered and in an argon-inerted'' atmosphere, over a period of twelve months. 33 refs., 134 figs., 98 tabs.

  5. Advances in the theory of the Hall-Petch relation, dislocation pileups and dislocation sources

    NASA Astrophysics Data System (ADS)

    Friedman, Lawrence Henry

    Advances in the theory of dislocations are reported. The Hall-Petch relation is extended, and a continuum level simulation of curvilinear dislocations is developed and used to study the operation of Frank-Read sources. The Hall-Petch relation states that the yield stress, sigma y, or strength against plastic deformation of polycrystalline materials is enhanced by decreasing the grain diameter: sigma y = Kd--1/2 + sigma 0, with K and sigma0 constants. One explanation of this relation is that yielding results from stress concentrated by queues of dislocations known as pileups. The pileup theory of the Hall-Petch relation is extended in two ways. First, two important aspects of pileup formation are incorporated into the theory: the existence of a threshold stress for dislocation production and the necessity of a finite-sized dislocation-free region in which a dislocation source may operate. Using a continuum theory of dislocation pileups, a closed form expression is obtained for the dependence of yield stress on grain size and source characteristics. The continuum model agrees closely with the corresponding discrete dislocation model. Second, a scaling theory describing the strength of lamellar materials is developed. The Hall-Petch relation is found to result from the similarity between dislocation densities of pileups of different lengths and under different applied stresses. For multilayers, the scaling theory predicts sigma y = KΛ--a + sigma0, where Λ is the compositional wavelength of the multilayer and a is a material dependent exponent. The scaling theory is then enlarged to incorporate parameters important to the operation of dislocation sources. The simulation of curvilinear dislocations, based on linear isotropic elasticity theory, includes self stress and dislocation-dislocation interactions. The operation stress of a Frank-Read source is found as a function of source size. Additionally, the plastic strain produced by a continuously operating source was

  6. Theory of nonlinear phononics for coherent light control of solids

    NASA Astrophysics Data System (ADS)

    Subedi, Alaska; Cavalleri, Andrea; Georges, Antoine

    2014-06-01

    We present a microscopic theory for ultrafast control of solids with high-intensity terahertz frequency optical pulses. When resonant with selected infrared-active vibrations, these pulses transiently modify the crystal structure and lead to new collective electronic properties. The theory predicts the dynamical path taken by the crystal lattice using first-principles calculations of the energy surface and classical equations of motion, as well as symmetry considerations. Two classes of dynamics are identified. In the perturbative regime, displacements along the normal mode coordinate of symmetry-preserving Raman active modes can be achieved by cubic anharmonicities. This explains the light-induced insulator-to-metal transition reported experimentally in manganites. We predict a regime in which ultrafast instabilities that break crystal symmetry can be induced. This nonperturbative effect involves a quartic anharmonic coupling and occurs above a critical threshold, below which the nonlinear dynamics of the driven mode displays softening and dynamical stabilization.

  7. Staying competitive with advanced technologies for closed loop supervisory control

    SciTech Connect

    Radl, B.J.; Roland, W.B.; Kish, B.

    1996-05-01

    The following paper discusses the experience gained from installing a neural network-based supervisory control system for selected combustion parameters at Penn Power`s New Castle station. The primary goal of the program was to reduce NO{sub x} emissions, while maintaining or improving unit heat rate. The advanced technologies used to implement supervisory control include: Neural Networks, Genetic Algorithms, Pattern Recognition and Data Visualization. The program was jointly funded by Ohio Edison, U.S. Department of Energy (DOE), Environmental Protection Agency (EPA) and Pegasus Technologies Corporation, under a National Industrial Competitiveness through Energy, Environment and Economics (NICE) grant program. The system is installed on a 1950s vintage Babcock & Wilcox front-fired (four levels) drum unit with a gross generation capacity of 146 MW The program linked a Unix workstation, where the supervisory control system resides, with a Network 90 Digital Control System (DCS). The system uses a neural network-based nonlinear model of the combustion process to interactively adjust setpoints and bias settings in the DCS. The system performs many {open_quotes}what if{close_quotes} simulations to optimize setpoints for the current operating conditions. The neural network model is updated periodically, learning from the most recent data. New setpoints are generated accordingly and downloaded into the DCS. Setpoint and bias adjustments are constrained within the original control system limits. Conditioning algorithms were developed to handle the inherently {open_quote}noisy{close_quote} input data and to provide stable output recommendations. Test results and parameters used for combustion optimization are summarized in this paper.

  8. Control of resistance plug welding using quantitative feedback theory

    SciTech Connect

    Bentley, A.E.; Horowitz, I. ||; Chait, Y.; Rodrigues, J.

    1996-12-01

    Resistance welding is used extensively throughout the manufacturing industry. Variations in weld quality often result in costly post-weld inspections. Applications of feed-back control to such processes have been limited by the lack of accurate models describing the nonlinear dynamics of this process. A new system based on electrode displacement feedback is developed that greatly improves quality control of the resistance plug welding process. The system is capable of producing repeatable welds of consistent displacement (and thus consistent quality), with wide variations in weld parameters. This paper describes the feedback design of a robust controller using Quantitative Feedback Theory for this highly complex process, and the experimental results of the applied system.

  9. A Controlled Trial of Sildenafil in Advanced Idiopathic Pulmonary Fibrosis

    PubMed Central

    2013-01-01

    BACKGROUND Sildenafil, a phosphodiesterase-5 inhibitor, may preferentially improve blood flow to well-ventilated regions of the lung in patients with advanced idiopathic pulmonary fibrosis, which could result in improvements in gas exchange. We tested the hypothesis that treatment with sildenafil would improve walk distance, dyspnea, and quality of life in patients with advanced idiopathic pulmonary fibrosis, defined as a carbon monoxide diffusion capacity of less than 35% of the predicted value. METHODS We conducted a double-blind, randomized, placebo-controlled trial of sildenafil in two periods. The first period consisted of 12 weeks of a double-blind comparison between sildenafil and a placebo control. The primary outcome was the proportion of patients with an increase in the 6-minute walk distance of 20% or more. Key secondary outcomes included changes in oxygenation, degree of dyspnea, and quality of life. The second period was a 12-week open-label evaluation involving all patients receiving sildenafil. RESULTS A total of 180 patients were enrolled in the study. The difference in the primary outcome was not significant, with 9 of 89 patients (10%) in the sildenafil group and 6 of 91 (7%) in the placebo group having an improvement of 20% or more in the 6-minute walk distance (P = 0.39). There were small but significant differences in arterial oxygenation, carbon monoxide diffusion capacity, degree of dyspnea, and quality of life favoring the sildenafil group. Serious adverse events were similar in the two study groups. CONCLUSIONS This study did not show a benefit for sildenafil for the primary outcome. The presence of some positive secondary outcomes creates clinical equipoise for further research. (Funded by the National Heart, Lung, and Blood Institute and others; ClinicalTrials.gov number, NCT00517933.) PMID:20484178

  10. MERCURY CONTROL WITH THE ADVANCED HYBRID PARTICULATE COLLECTOR

    SciTech Connect

    Stanley J. Miller; Grant E. Dunham; Michelle R. Olderbak

    2001-11-01

    This project was awarded under U.S. Department of Energy (DOE) Program Solicitation DE-PS26-00NT40769 and specifically addresses Technical Topical Area 4--Testing Novel and Less Mature Control Technologies on Actual Flue Gas at the Pilot-Scale. The project team will include the Energy and Environmental Research Center (EERC) as the main contractor, W.L. Gore and Associates, Inc., as a technical and financial partner, and the Big Stone Power Plant operated by Otter Tail Power Company, which will host the field testing portion of the research. Since 1995, DOE has supported development of a new concept in particulate control, called the advanced hybrid particulate collector (AHPC). The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in a unique configuration, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emission with conventional ESPs, and it solves the problem of reentrainment and re-collection of dust in conventional baghouses. The AHPC appears to have unique advantages for mercury control over baghouses or ESPs as an excellent gas-solid contactor. The objective of the three-task project is to demonstrate 90% total mercury control in the AHPC at a lower cost than current mercury control estimates. The approach includes bench-scale batch testing that ties the new work to previous results and links results with larger-scale pilot testing with real flue gas on a coal-fired combustion system, pilot-scale testing on a coal-fired combustion system with both a pulse-jet baghouse and an AHPC to prove or disprove the research hypotheses, and field demonstration pilot-scale testing at a utility power plant to prove scaleup and demonstrate longer-term mercury control. This project, if successful, will demonstrate at the pilot-scale level a

  11. MERCURY CONTROL WITH THE ADVANCED HYBRID PARTICULATE COLLECTOR

    SciTech Connect

    Ye Zhuang; Stanley J. Miller; Grant E. Dunham; Michelle R. Olderbak

    2002-05-01

    This project was awarded under U.S. Department of Energy (DOE) Program Solicitation DE-PS26-00NT40769 and specifically addresses Technical Topical Area 4--Testing Novel and Less Mature Control Technologies on Actual Flue Gas at the Pilot Scale. The project team includes the Energy & Environmental Research Center (EERC) as the main contractor; W.L. Gore & Associates, Inc., as a technical and financial partner; and the Big Stone Power Plant operated by Otter Tail Power Company, which will host the field testing portion of the research. Since 1995, DOE has supported development of a new concept in particulate control, called the advanced hybrid particulate collector (AHPC). The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in a unique configuration, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emission with conventional ESPs, and it solves the problem of reentrainment and re-collection of dust in conventional baghouses. The AHPC appears to have unique advantages for mercury control over baghouses or ESPs as an excellent gas-solid contactor. The objective of the three-task project is to demonstrate 90% total mercury control in the AHPC at a lower cost than current mercury control estimates. The approach includes bench-scale batch testing that ties the new work to previous results and links results with larger-scale pilot testing with real flue gas on a coal-fired combustion system, pilot-scale testing on a coal-fired combustion system with both a pulse-jet baghouse and an AHPC to prove or disprove the research hypotheses, and field demonstration pilot-scale testing at a utility power plant to prove scaleup and demonstrate longer-term mercury control. This project, if successful, will demonstrate at the pilot-scale level a technology

  12. 7 CFR 4288.137 - Succession and loss of control of advanced biofuel facilities and production.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 15 2014-01-01 2014-01-01 false Succession and loss of control of advanced biofuel... PROGRAMS Advanced Biofuel Payment Program General Provisions Payment Provisions § 4288.137 Succession and loss of control of advanced biofuel facilities and production. (a) Contract succession. An entity...

  13. 7 CFR 4288.137 - Succession and loss of control of advanced biofuel facilities and production.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 15 2012-01-01 2012-01-01 false Succession and loss of control of advanced biofuel... PROGRAMS Advanced Biofuel Payment Program General Provisions § 4288.137 Succession and loss of control of advanced biofuel facilities and production. (a) Contract succession. An entity who becomes the...

  14. 7 CFR 4288.137 - Succession and loss of control of advanced biofuel facilities and production.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 15 2013-01-01 2013-01-01 false Succession and loss of control of advanced biofuel... PROGRAMS Advanced Biofuel Payment Program General Provisions § 4288.137 Succession and loss of control of advanced biofuel facilities and production. (a) Contract succession. An entity who becomes the...

  15. Application of H[infinity] control theory to power control of a nonlinear reactor model

    SciTech Connect

    Suzuki, Katsuo; Shimazaki, Junya; Shinohara, Yoshikuni . Dept. of Reactor Engineering)

    1993-10-01

    The H[infinity] control theory is applied to the compensator design of a nonlinear nuclear reactor model, and the results are compared with standard linear quadratic Gaussian (LQG) control. The reactor model is assumed to be provided with a control rod drive system having the compensation of rod position feedback. The nonlinearity of the reactor model exerts a great influence on the stability of the control system, and hence, it is desirable for a power control system of a nuclear reactor to achieve robust stability and to improve the sensitivity of the feedback control system. A computer simulation based on a power control system synthesized by LQG control was performed revealing that the control system has some stationary offset and less stability. Therefore, here, attention is given to the development of a methodology for robust control that can withstand exogenous disturbances and nonlinearity in view of system parameter changes. The developed methodology adopts H[infinity] control theory in the feedback system and shows interesting features of robustness. The results of the computer simulation indicate that the feedback control system constructed by the developed H[infinity] compensator possesses sufficient robustness of control on the stability and disturbance attenuation, which are essential for the safe operation of a nuclear reactor.

  16. Second Generation Advanced Reburning for High Efficiency NOx Control

    SciTech Connect

    Vladimir M. Zamansky; Peter M. Maly; Vitali V. Lissianski; Mark S. Sheldon; David Moyeda; Roy Payne

    2001-06-30

    This project develops a family of novel Second Generation Advanced Reburning (SGAR) NO{sub x} control technologies, which can achieve 95% NO{sub x} control in coal fired boilers at a significantly lower cost than Selective Catalytic Reduction (SCR). The conventional Advanced Reburning (AR) process integrates basic reburning and N-agent injection. The SGAR systems include six AR variants: (1) AR-Lean--injection of the N-agent and promoter along with overfire air; (2) AR-Rich--injection of N-agent and promoter into the reburning zone; (3) Multiple Injection Advanced Reburning (MIAR)--injection of N-agents and promoters both into the reburning zone and with overfire air; (4) AR-Lean + Promoted SNCR--injection of N-agents and promoters with overfire air and into the temperature zone at which Selective Non-Catalytic Reduction (SNCR) is effective; (5) AR-Rich + Promoted SNCR--injection of N-agents and promoters into the reburning zone and into the SNCR zone; and (6) Promoted Reburning + Promoted SNCR--basic or promoted reburning followed by basic or promoted SNCR process. The project was conducted in two phases over a five-year period. The work included a combination of analytical and experimental studies to confirm the process mechanisms, identify optimum process configurations, and develop a design methodology for full-scale applications. Phase I was conducted from October, 1995 to September, 1997 and included both analytical studies and tests in bench and pilot-scale test rigs. Phase I moved AR technology to Maturity Level III-Major Subsystems. Phase II is conducted over a 45 month period (October, 1997-June, 2001). Phase II included evaluation of alternative promoters, development of alternative reburning fuel and N-Agent jet mixing systems, and scale up. The goal of Phase II was to move the technology to Maturity Level I-Subscale Integrated System. Tests in combustion facility ranging in firing rate from 0.1 x 10{sup 6} to 10 x 10{sup 6} Btu/hr demonstrated the

  17. MERCURY CONTROL WITH THE ADVANCED HYBRID PARTICULATE COLLECTOR

    SciTech Connect

    Charlene R. Crocker; Steven A. Benson; Stanley J. Miller

    2003-11-01

    This project was awarded under U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) Program Solicitation DE-PS26-00NT40769 and specifically addresses Technical Topical Area 4--Testing Novel and Less Mature Control Technologies on Actual Flue Gas at the Pilot Scale. The project team includes the Energy & Environmental Research Center (EERC) as the main contractor; W.L. Gore & Associates, Inc., as a technical and financial partner; and the Big Stone Plant operated by Otter Tail Power Company, host for the field-testing portion of the research. Since 1995, DOE has supported development of a new concept in particulate control called the advanced hybrid particulate collector (AHPC). The AHPC has been licensed to W.L. Gore & Associates, Inc., and is now marketed as the Advanced Hybrid{trademark} filter by Gore. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in a unique configuration, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The AHPC provides ultra-high collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and it solves the problem of reentrainment and re-collection of dust in conventional baghouses. The AHPC appears to have unique advantages for mercury control over baghouses or ESPs as an excellent gas-solid contactor. The objective of the original 5-task project is to demonstrate 90% total mercury control in the AHPC at a lower cost than current mercury control estimates. The approach includes bench-scale batch testing that ties the new work to previous results and links results with larger-scale pilot testing with real flue gas on a coal-fired combustion system, pilot-scale testing on a coal-fired combustion system with both a pulse-jet baghouse and an AHPC to prove or disprove the research hypotheses, and field demonstration pilot-scale testing at a

  18. Mercury Control With The Advanced Hybrid Particulate Collector

    SciTech Connect

    Steven A. Benson; Stanley J. Miller; Charlene R. Crocker; Kevin C. Galbreath; Jason D. Laumb; Jill M. Zola; Ye Zhuang; Michelle R. Olderbak

    2003-12-31

    This project was awarded under U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) Program Solicitation DE-PS26-00NT40769 and specifically addresses Technical Topical Area 4 - Testing Novel and Less Mature Control Technologies on Actual Flue Gas at the Pilot Scale. The project team includes the Energy & Environmental Research Center (EERC) as the main contractor; W.L. Gore & Associates, Inc., as a technical and financial partner; and the Big Stone Plant operated by Otter Tail Power Company, host for the field-testing portion of the research. Since 1995, DOE has supported development of a new concept in particulate control called the advanced hybrid particulate collector (AHPC). The AHPC has been licensed to W.L. Gore and Associates, Inc., and is now marketed as the Advanced Hybrid{trademark} filter by Gore. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in a unique configuration, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and it solves the problem of reentrainment and re-collection of dust in conventional baghouses. The AHPC appears to have unique advantages for mercury control over baghouses or ESPs as an excellent gas-solid contactor. The objective of the original 5-task project is to demonstrate 90% total mercury control in the AHPC at a lower cost than current mercury control estimates. The approach includes benchscale batch testing that ties the new work to previous results and links results with larger-scale pilot testing with real flue gas on a coal-fired combustion system, pilot-scale testing on a coal fired combustion system with both a pulse-jet baghouse and an AHPC to prove or disprove the research hypotheses, and field demonstration pilot-scale testing at

  19. Mercury Control With The Advanced Hybrid Particulate Collector

    SciTech Connect

    Steven A. Benson; Stanley J. Miller; Charlene R. Crocker; Kevin C. Galbreath; Jason D. Laumb; Jill M. Zola; Ye Zhuang; Michelle R. Olderbak

    2004-03-31

    This project was awarded under U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) Program Solicitation DE-PS26-00NT40769 and specifically addresses Technical Topical Area 4 - Testing Novel and Less Mature Control Technologies on Actual Flue Gas at the Pilot Scale. The project team includes the Energy & Environmental Research Center (EERC) as the main contractor; W.L. Gore & Associates, Inc., as a technical and financial partner; and the Big Stone Plant operated by Otter Tail Power Company, host for the field-testing portion of the research. Since 1995, DOE has supported development of a new concept in particulate control called the advanced hybrid particulate collector (AHPC). The AHPC has been licensed to W.L. Gore and Associates, Inc., and is now marketed as the Advanced Hybrid{trademark} filter by Gore. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in a unique configuration, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and it solves the problem of reentrainment and re-collection of dust in conventional baghouses. The AHPC appears to have unique advantages for mercury control over baghouses or ESPs as an excellent gas-solid contactor. The objective of the original 5-task project is to demonstrate 90% total mercury control in the AHPC at a lower cost than current mercury control estimates. The approach includes benchscale batch testing that ties the new work to previous results and links results with larger-scale pilot testing with real flue gas on a coal-fired combustion system, pilot-scale testing on a coal fired combustion system with both a pulse-jet baghouse and an AHPC to prove or disprove the research hypotheses, and field demonstration pilot-scale testing at

  20. MERCURY CONTROL WITH THE ADVANCED HYBRID PARTICULATE COLLECTOR

    SciTech Connect

    Steven A. Benson; Stanley J. Miller; Charlene R. Crocker; Kevin C. Galbreath; Jason D. Laumb; Jill M. Zola; Ye Zhuang; Michelle R. Olderbak

    2004-08-01

    This project was awarded under U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) Program Solicitation DE-PS26-00NT40769 and specifically addresses Technical Topical Area 4-Testing Novel and Less Mature Control Technologies on Actual Flue Gas at the Pilot Scale. The project team includes the Energy & Environmental Research Center (EERC) as the main contractor; W.L. Gore & Associates, Inc., as a technical and financial partner; and the Big Stone Plant operated by Otter Tail Power Company, host for the field-testing portion of the research. Since 1995, DOE has supported development of a new concept in particulate control called the advanced hybrid particulate collector (AHPC). The AHPC has been licensed to W.L. Gore & Associates, Inc., and is now marketed as the Advanced Hybrid{trademark} filter by Gore. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in a unique configuration, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and it solves the problem of reentrainment and re-collection of dust in conventional baghouses. The AHPC appears to have unique advantages for mercury control over baghouses or ESPs as an excellent gas-solid contactor. The objective of the original 5-task project is to demonstrate 90% total mercury control in the AHPC at a lower cost than current mercury control estimates. The approach includes bench-scale batch testing that ties the new work to previous results and links results with larger-scale pilot testing with real flue gas on a coal-fired combustion system, pilot-scale testing on a coal-fired combustion system with both a pulse-jet baghouse and an AHPC to prove or disprove the research hypotheses, and field demonstration pilot-scale testing at a

  1. Optimization of microstructure during deformation processing using control theory principles

    SciTech Connect

    Venugopal, S.; Medina, E.A.; Malas, J.C. III; Medeiros, S.; Frazier, W.G.; Mullins, W.M.; Srinivasan, R.

    1997-02-01

    The development of optimal design and control methods for manufacturing processes is needed for effectively reducing part cost, improving part delivery schedules and producing specified part quality on a repeatable basis. A new strategy for systematically calculating near optimal control parameters for hot deformation processes for microstructural control is presented in this communication. This approach is based on modern control theory and involves developing state-space models from available material behavior and hot deformation process models. The control system design consists of two basic stages and analysis and optimization are critical in both stages. In the first stage, the kinetics of certain dynamic microstructural behavior and the intrinsic hot workability of the material are used, along with an appropriately chosen optimality criterion, to calculate optimum strain, strain-rate, and temperature trajectories for processing. A suitable process simulation model is then used in the second stage to calculate process control parameters, such as ram velocity, die profiles and billet temperature, which approximately achieve the strain, strain-rate, and temperate trajectories calculated in the first stage at selected areas of the workpiece. The validity of this approach has been demonstrated with an example on hot extrusion of steel.

  2. Application of nonlinear feedback control theory to supermaneuverable aircraft

    NASA Technical Reports Server (NTRS)

    Garrard, William L.; Enns, Dale F.

    1991-01-01

    Controlled flight at extremely high angles of attack, far exceeding the stall angle, and/or at high angular rates is sometimes referred to as supermaneuvering flight. The objective was to examine methods for design of control laws for aircraft performing supermaneuvers. Since the equations which govern the motion of aircraft during supermaneuvers are nonlinear, this study concentrated on nonlinear control law design procedures. The two nonlinear techniques considered were Nonlinear Quadratic Regulator (NLQR) theory and nonlinear dynamic inversion. A conventional gain scheduled proportional plus integral (P + I) controller was also developed to serve as a baseline design typical of current control laws used in aircraft. A mathematical model of a generic supermaneuverable aircraft was developed from data obtained from the literature. A detailed computer simulation of the aircraft was also developed. This simulation allowed the flying of proposed supermaneuvers and was used to evaluate the performance of the control law designs and to generate linearized models of the aircraft at different flight conditions.

  3. Combining Optimal Control Theory and Molecular Dynamics for Protein Folding

    PubMed Central

    Arkun, Yaman; Gur, Mert

    2012-01-01

    A new method to develop low-energy folding routes for proteins is presented. The novel aspect of the proposed approach is the synergistic use of optimal control theory with Molecular Dynamics (MD). In the first step of the method, optimal control theory is employed to compute the force field and the optimal folding trajectory for the atoms of a Coarse-Grained (CG) protein model. The solution of this CG optimization provides an harmonic approximation of the true potential energy surface around the native state. In the next step CG optimization guides the MD simulation by specifying the optimal target positions for the atoms. In turn, MD simulation provides an all-atom conformation whose positions match closely the reference target positions determined by CG optimization. This is accomplished by Targeted Molecular Dynamics (TMD) which uses a bias potential or harmonic restraint in addition to the usual MD potential. Folding is a dynamical process and as such residues make different contacts during the course of folding. Therefore CG optimization has to be reinitialized and repeated over time to accomodate these important changes. At each sampled folding time, the active contacts among the residues are recalculated based on the all-atom conformation obtained from MD. Using the new set of contacts, the CG potential is updated and the CG optimal trajectory for the atoms is recomputed. This is followed by MD. Implementation of this repetitive CG optimization - MD simulation cycle generates the folding trajectory. Simulations on a model protein Villin demonstrate the utility of the method. Since the method is founded on the general tools of optimal control theory and MD without any restrictions, it is widely applicable to other systems. It can be easily implemented with available MD software packages. PMID:22238629

  4. Not that Different in Theory: Discussing the Control-Value Theory of Emotions in Online Learning Environments

    ERIC Educational Resources Information Center

    Daniels, Lia M.; Stupnisky, Robert H.

    2012-01-01

    This commentary investigates the extent to which the control-value theory of emotions (Pekrun, 2006) is applicable in online learning environments. Four empirical studies in this special issue of "The Internet and Higher Education" explicitly used the control-value theory as their theoretical framework and several others have components of the…

  5. Development of an advanced pitch active control system for a wide body jet aircraft

    NASA Technical Reports Server (NTRS)

    Guinn, Wiley A.; Rising, Jerry J.; Davis, Walt J.

    1984-01-01

    An advanced PACS control law was developed for a commercial wide-body transport (Lockheed L-1011) by using modern control theory. Validity of the control law was demonstrated by piloted flight simulation tests on the NASA Langley visual motion simulator. The PACS design objective was to develop a PACS that would provide good flying qualities to negative 10 percent static stability margins that were equivalent to those of the baseline aircraft at a 15 percent static stability margin which is normal for the L-1011. Also, the PACS was to compensate for high-Mach/high-g instabilities that degrade flying qualities during upset recoveries and maneuvers. The piloted flight simulation tests showed that the PACS met the design objectives. The simulation demonstrated good flying qualities to negative 20 percent static stability margins for hold, cruise and high-speed flight conditions. Analysis and wind tunnel tests performed on other Lockheed programs indicate that the PACS could be used on an advanced transport configuration to provide a 4 percent fuel savings which results from reduced trim drag by flying at negative static stability margins.

  6. Advanced illumination control algorithm for medical endoscopy applications

    NASA Astrophysics Data System (ADS)

    Sousa, Ricardo M.; Wäny, Martin; Santos, Pedro; Morgado-Dias, F.

    2015-05-01

    CMOS image sensor manufacturer, AWAIBA, is providing the world's smallest digital camera modules to the world market for minimally invasive surgery and one time use endoscopic equipment. Based on the world's smallest digital camera head and the evaluation board provided to it, the aim of this paper is to demonstrate an advanced fast response dynamic control algorithm of the illumination LED source coupled to the camera head, over the LED drivers embedded on the evaluation board. Cost efficient and small size endoscopic camera modules nowadays embed minimal size image sensors capable of not only adjusting gain and exposure time but also LED illumination with adjustable illumination power. The LED illumination power has to be dynamically adjusted while navigating the endoscope over changing illumination conditions of several orders of magnitude within fractions of the second to guarantee a smooth viewing experience. The algorithm is centered on the pixel analysis of selected ROIs enabling it to dynamically adjust the illumination intensity based on the measured pixel saturation level. The control core was developed in VHDL and tested in a laboratory environment over changing light conditions. The obtained results show that it is capable of achieving correction speeds under 1 s while maintaining a static error below 3% relative to the total number of pixels on the image. The result of this work will allow the integration of millimeter sized high brightness LED sources on minimal form factor cameras enabling its use in endoscopic surgical robotic or micro invasive surgery.

  7. User type certification for advanced flight control systems

    NASA Technical Reports Server (NTRS)

    Gilson, Richard D.; Abbott, David W.

    1994-01-01

    Advanced avionics through flight management systems (FMS) coupled with autopilots can now precisely control aircraft from takeoff to landing. Clearly, this has been the most important improvement in aircraft since the jet engine. Regardless of the eventual capabilities of this technology, it is doubtful that society will soon accept pilotless airliners with the same aplomb they accept driverless passenger trains. Flight crews are still needed to deal with inputing clearances, taxiing, in-flight rerouting, unexpected weather decisions, and emergencies; yet it is well known that the contribution of human errors far exceed those of current hardware or software systems. Thus human errors remain, and are even increasing in percentage as the largest contributor to total system error. Currently, the flight crew is regulated by a layered system of certification: by operation, e.g., airline transport pilot versus private pilot; by category, e.g., airplane versus helicopter; by class, e.g., single engine land versus multi-engine land; and by type (for larger aircraft and jet powered aircraft), e.g., Boeing 767 or Airbus A320. Nothing in the certification process now requires an in-depth proficiency with specific types of avionics systems despite their prominent role in aircraft control and guidance.

  8. Advanced Branching Control and Characterization of Inorganic Semiconducting Nanocrystals

    SciTech Connect

    Hughes, Steven Michael

    2007-01-01

    The ability to finely tune the size and shape of inorganic semiconducting nanocrystals is an area of great interest, as the more control one has, the more applications will be possible for their use. The first two basic shapes develped in nanocrystals were the sphere and the anistropic nanorod. the II_VI materials being used such as Cadmium Selenide (CdSe) and Cadmium Telluride (CdTe), exhibit polytypism, which allows them to form in either the hexagonally packed wurtzite or cubically packed zinc blende crystalline phase. The nanorods are wurtzite with the length of the rod growing along the c-axis. As this grows, stacking faults may form, which are layers of zinc blende in the otherwise wurtzite crystal. Using this polytypism, though, the first generation of branched crystals were developed in the form of the CdTe tetrapod. This is a nanocrystal that nucleates in the zincblend form, creating a tetrahedral core, on which four wurtzite arms are grown. This structure opened up the possibility of even more complex shapes and applications. This disseration investigates the advancement of branching control and further understanding the materials polytypism in the form of the stacking faults in nanorods.

  9. Temperature controlled material irradiation in the advanced test reactor

    NASA Astrophysics Data System (ADS)

    Ingram, F. W.; Palmer, A. J.; Stites, D. J.

    1998-10-01

    The United States Department of Energy (US DOE) has initiated the development of an Irradiation Test Vehicle (ITV) for fusion materials irradiation at the Advanced Test Reactor (ATR) in Idaho Falls, Idaho, USA. The ITV is capable of providing neutron spectral tailoring and individual temperature control for up to 15 experiment capsules simultaneously. The test vehicle consists of three In-Pile Tubes (IPTs) running the length of the reactor vessel. These IPTs are kept dry and test trains with integral instrumentation are inserted and removed through a transfer shield plate above the reactor vessel head. The test vehicle is designed to irradiate specimens as large as 2.2 cm in diameter, at temperatures of 250-800°C, achieving neutron damage rates as high as 10 displacements per atom per year. The high fast to thermal neutron flux ratio required for fusion materials testing is accomplished by using an aluminum filler to displace as much water as possible from the flux trap and surrounding the filler piece with a ring of replaceable neutron absorbing material. The gas blend temperature control system remains in place from test to test, thus hardware costs for new tests are limited to the experiment capsule train and integral instrumentation.

  10. A method for obtaining practical flutter-suppression control laws using results of optimal control theory

    NASA Technical Reports Server (NTRS)

    Newson, J. R.

    1979-01-01

    The results of optimal control theory are used to synthesize a feedback filter. The feedback filter is used to force the output of the filtered frequency response to match that of a desired optimal frequency response over a finite frequency range. This matching is accomplished by employing a nonlinear programing algorithm to search for the coefficients of the feedback filter that minimize the error between the optimal frequency response and the filtered frequency response. The method is applied to the synthesis of an active flutter-suppression control law for an aeroelastic wind-tunnel model. It is shown that the resulting control law suppresses flutter over a wide range of subsonic Mach numbers. This is a promising method for synthesizing practical control laws using the results of optimal control theory.

  11. Integrated Application of Active Controls (IAAC) technology to an advanced subsonic transport project: current and advanced act control system definition study

    SciTech Connect

    Not Available

    1982-04-01

    The Current and Advanced Technology ACT control system definition tasks of the Integrated Application of Active Controls (IAAC) Technology project within the Energy Efficient Transport Program are summarized. The systems mechanize six active control functions: (1) pitch augmented stability (2) angle of attack limiting (3) lateral/directional augmented stability (4) gust load alleviation (5) maneuver load control and (6) flutter mode control. The redundant digital control systems meet all function requirements with required reliability and declining weight and cost as advanced technology is introduced.

  12. Integrated Application of Active Controls (IAAC) technology to an advanced subsonic transport project: Current and advanced act control system definition study

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The Current and Advanced Technology ACT control system definition tasks of the Integrated Application of Active Controls (IAAC) Technology project within the Energy Efficient Transport Program are summarized. The systems mechanize six active control functions: (1) pitch augmented stability; (2) angle of attack limiting; (3) lateral/directional augmented stability; (4) gust load alleviation; (5) maneuver load control; and (6) flutter mode control. The redundant digital control systems meet all function requirements with required reliability and declining weight and cost as advanced technology is introduced.

  13. De-tabooing dying control - a grounded theory study

    PubMed Central

    2013-01-01

    Background Dying is inescapable yet remains a neglected issue in modern health care. The research question in this study was “what is going on in the field of dying today?” What emerged was to eventually present a grounded theory of control of dying focusing specifically on how people react in relation to issues about euthanasia and physician-assisted suicide (PAS). Methods Classic grounded theory was used to analyze interviews with 55 laypersons and health care professionals in North America and Europe, surveys on attitudes to PAS among physicians and the Swedish general public, and scientific literature, North American discussion forum websites, and news sites. Results Open awareness of the nature and timing of a patient’s death became common in health care during the 1960s in the Western world. Open dying awareness contexts can be seen as the start of a weakening of a taboo towards controlled dying called de-tabooing. The growth of the hospice movement and palliative care, but also the legalization of euthanasia and PAS in the Benelux countries, and PAS in Montana, Oregon and Washington further represents de-tabooing dying control. An attitude positioning between the taboo of dying control and a growing taboo against questioning patient autonomy and self-determination called de-paternalizing is another aspect of de-tabooing. When confronted with a taboo, people first react emotionally based on “gut feelings” - emotional positioning. This is followed by reasoning and label wrestling using euphemisms and dysphemisms - reflective positioning. Rarely is de-tabooing unconditional but enabled by stipulated positioning as in soft laws (palliative care guidelines) and hard laws (euthanasia/PAS legislation). From a global perspective three shapes of dying control emerge. First, suboptimal palliative care in closed awareness contexts seen in Asian, Islamic and Latin cultures, called closed dying. Second, palliative care and sedation therapy, but not euthanasia

  14. Investigating friendship quality: an exploration of self-control and social control theories' friendship hypotheses.

    PubMed

    Boman, John H; Krohn, Marvin D; Gibson, Chris L; Stogner, John M

    2012-11-01

    While associations with deviant peers are well understood to impact individual development, less is understood about the relationship between friendship quality and delinquency. Two criminological theories--social control theory and self-control theory--are able to offer an explanation for the latter relationship. Social control and self-control theories both premise that delinquents will have largely fractured, weak, and "cold and brittle" friendships. This study investigates how variations in perceptions of friendship quality are related to the delinquency, maternal attachment, school attachment, and self-control levels of both a participant and his/her close friend. To explore these relationships, we use a diverse (14% black; 18% Hispanic; 9% Asian) sample of 2,154 emerging adults within 1,077 friendship pairs (66% female). In each dyad, both members perceived the friendship's quality and reported personal markers of delinquency, social bonds, and self-control. Several series of multilevel models are estimated that regress each participant's friendship quality perception onto the participant's and their friend's delinquency, attachments, self-control, and demographic characteristics. Results show that delinquents have as intense, or more intense, friendships as non-delinquents. However, low levels of both actor and partner attachments and self-control are independently related to low friendship quality, and this is especially true for self-control. Supplemental analyses demonstrate that the effect of self-control on friendship quality may be reduced when individuals in dyads are delinquent. In conclusion, studies that address friendship quality without including characteristics of multiple members of the friendship are only capturing part of one's estimate of friendship quality. PMID:22367018

  15. TDDFT-based local control theory for chemical reactions

    NASA Astrophysics Data System (ADS)

    Tavernelli, Ivano; Curchod, Basile F. E.; Penfold, Thomas J.

    In this talk I will describe the implementation of local control theory for laser pulse shaping within the framework of TDDFT-based nonadiabatic dynamics. The method is based on a set of modified Tully's surface hopping equations and provides an efficient way to control the population of a selected reactive state of interest through the coupling with an external time-dependent electric field generated on-the-fly during the dynamics. This approach is applied to the investigation of the photoinduced intramolecular proton transfer reaction in 4-hydroxyacridine in gas phase and in solution. The generated pulses reveal important information about the underlying excited-state nuclear dynamics highlighting the involvement of collective vibrational modes that would be neglected in studies performed on model systems. Finally, this approach can help to shed new light on the photophysics and photochemistry of complex molecular systems and guide the design of novel reaction paths.

  16. Decision theory applied to image quality control in radiology

    PubMed Central

    Lessa, Patrícia S; Caous, Cristofer A; Arantes, Paula R; Amaro, Edson; de Souza, Fernando M Campello

    2008-01-01

    Background The present work aims at the application of the decision theory to radiological image quality control (QC) in diagnostic routine. The main problem addressed in the framework of decision theory is to accept or reject a film lot of a radiology service. The probability of each decision of a determined set of variables was obtained from the selected films. Methods Based on a radiology service routine a decision probability function was determined for each considered group of combination characteristics. These characteristics were related to the film quality control. These parameters were also framed in a set of 8 possibilities, resulting in 256 possible decision rules. In order to determine a general utility application function to access the decision risk, we have used a simple unique parameter called r. The payoffs chosen were: diagnostic's result (correct/incorrect), cost (high/low), and patient satisfaction (yes/no) resulting in eight possible combinations. Results Depending on the value of r, more or less risk will occur related to the decision-making. The utility function was evaluated in order to determine the probability of a decision. The decision was made with patients or administrators' opinions from a radiology service center. Conclusion The model is a formal quantitative approach to make a decision related to the medical imaging quality, providing an instrument to discriminate what is really necessary to accept or reject a film or a film lot. The method presented herein can help to access the risk level of an incorrect radiological diagnosis decision. PMID:19014545

  17. Advanced modelling, monitoring, and process control of bioconversion systems

    NASA Astrophysics Data System (ADS)

    Schmitt, Elliott C.

    Production of fuels and chemicals from lignocellulosic biomass is an increasingly important area of research and industrialization throughout the world. In order to be competitive with fossil-based fuels and chemicals, maintaining cost-effectiveness is critical. Advanced process control (APC) and optimization methods could significantly reduce operating costs in the biorefining industry. Two reasons APC has previously proven challenging to implement for bioprocesses include: lack of suitable online sensor technology of key system components, and strongly nonlinear first principal models required to predict bioconversion behavior. To overcome these challenges batch fermentations with the acetogen Moorella thermoacetica were monitored with Raman spectroscopy for the conversion of real lignocellulosic hydrolysates and a kinetic model for the conversion of synthetic sugars was developed. Raman spectroscopy was shown to be effective in monitoring the fermentation of sugarcane bagasse and sugarcane straw hydrolysate, where univariate models predicted acetate concentrations with a root mean square error of prediction (RMSEP) of 1.9 and 1.0 g L-1 for bagasse and straw, respectively. Multivariate partial least squares (PLS) models were employed to predict acetate, xylose, glucose, and total sugar concentrations for both hydrolysate fermentations. The PLS models were more robust than univariate models, and yielded a percent error of approximately 5% for both sugarcane bagasse and sugarcane straw. In addition, a screening technique was discussed for improving Raman spectra of hydrolysate samples prior to collecting fermentation data. Furthermore, a mechanistic model was developed to predict batch fermentation of synthetic glucose, xylose, and a mixture of the two sugars to acetate. The models accurately described the bioconversion process with an RMSEP of approximately 1 g L-1 for each model and provided insights into how kinetic parameters changed during dual substrate

  18. Sarcasm and advanced theory of mind understanding in children and adults with prelingual deafness.

    PubMed

    O'Reilly, Karin; Peterson, Candida C; Wellman, Henry M

    2014-07-01

    Two studies addressed key theoretical debates in theory of mind (ToM) development by comparing (a) deaf native signers (n = 18), (b) deaf late signers (n = 59), and (c) age-matched hearing persons (n = 74) in childhood (Study 1: n = 81) and adulthood (Study 2: n = 70) on tests of first- and second-order false belief and conversational sarcasm. Results showed ToM development to be a life span phenomenon for deaf and hearing people alike. Native and late signers were outperformed by hearing peers on advanced ToM in childhood (M = 9 years), but in adulthood (M = 40 years), native signers had caught up, whereas late signers had not. Findings highlight the extended importance of conversational interaction for ToM growth. PMID:24798505

  19. Roles for software technologies in advancing research and theory in educational psychology.

    PubMed

    Hadwin, Allyson F; Winne, Philip H; Nesbit, John C

    2005-03-01

    While reviews abound on theoretical topics in educational psychology, it is rare that we examine our field's instrumentation development, and what effects this has on educational psychology's evolution. To repair this gap, this paper investigates and reveals the implications of software technologies for researching and theorizing about core issues in educational psychology. From a set of approximately 1,500 articles published between 1999 and 2004, we sampled illustrative studies and organized them into four broad themes: (a) innovative ways to operationalize variables, (b) the changing nature of instructional interventions, (c) new fields of research in educational psychology, and (d) new constructs to be examined. In each area, we identify novel uses of these technologies and suggest how they may advance, and, in some instances, reshape theory and methodology. Overall, we demonstrate that software technologies hold significant potential to elaborate research in the field. PMID:15831178

  20. Controller design approaches for large space structures using LQG control theory. [Linear Quadratic Gaussian

    NASA Technical Reports Server (NTRS)

    Joshi, S. M.; Groom, N. J.

    1979-01-01

    The paper presents several approaches for the design of reduced order controllers for large space structures. These approaches are shown to be based on LQG control theory and include truncation, modified truncation regulators and estimators, use of higher order estimators, selective modal suppression, and use of polynomial estimators. Further, the use of direct sensor feedback, as opposed to a state estimator, is investigated for some of these approaches. Finally, numerical results are given for a long free beam.

  1. Project Management Using Modern Guidance, Navigation and Control Theory

    NASA Technical Reports Server (NTRS)

    Hill, Terry

    2010-01-01

    The idea of control theory and its application to project management is not new, however literature on the topic and real-world applications is not as readily available and comprehensive in how all the principals of Guidance, Navigation and Control (GN&C) apply. This paper will address how the fundamental principals of modern GN&C Theory have been applied to NASA's Constellation Space Suit project and the results in the ability to manage the project within cost, schedule and budget. A s with physical systems, projects can be modeled and managed with the same guiding principles of GN&C as if it were a complex vehicle, system or software with time-varying processes, at times non-linear responses, multiple data inputs of varying accuracy and a range of operating points. With such systems the classic approach could be applied to small and well-defined projects; however with larger, multi-year projects involving multiple organizational structures, external influences and a multitude of diverse resources, then modern control theory is required to model and control the project. The fundamental principals of G N&C stated that a system is comprised of these basic core concepts: State, Behavior, Control system, Navigation system, Guidance and Planning Logic, Feedback systems. The state of a system is a definition of the aspects of the dynamics of the system that can change, such as position, velocity, acceleration, coordinate-based attitude, temperature, etc. The behavior of the system is more of what changes are possible rather than what can change, which is captured in the state of the system. The behavior of a system is captured in the system modeling and if properly done, will aid in accurate system performance prediction in the future. The Control system understands the state and behavior of the system and feedback systems to adjust the control inputs into the system. The Navigation system takes the multiple data inputs and based upon a priori knowledge of the input

  2. Recent Advances in Understanding Integrative Control of Potassium Homeostasis

    PubMed Central

    Youn, Jang H.; McDonough, Alicia A.

    2016-01-01

    The potassium homeostatic system is very tightly regulated. Recent studies have shed light on the sensing and molecular mechanisms responsible for this tight control. In addition to classic feedback regulation mediated by a rise in extracellular fluid (ECF) [K+], there is evidence for a feedforward mechanism: Dietary K+ intake is sensed in the gut, and an unidentified gut factor is activated to stimulate renal K+ excretion. This pathway may explain renal and extrarenal responses to altered K+ intake that occur independently of changes in ECF [K+]. Mechanisms for conserving ECF K+ during fasting or K+ deprivation have been described: Kidney NADPH oxidase activation initiates a cascade that provokes the retraction of K+ channels from the cell membrane, and muscle becomes resistant to insulin stimulation of cellular K+ uptake. How these mechanisms are triggered by K+ deprivation remains unclear. Cellular AMP kinase–dependent protein kinase activity provokes the acute transfer of K+ from the ECF to the ICF, which may be important in exercise or ischemia. These recent advances may shed light on the beneficial effects of a high-K+ diet for the cardiovascular system. PMID:18759636

  3. Coal surface control for advanced fine coal flotation

    SciTech Connect

    Fuerstenau, D.W.; Sastry, K.V.S.; Hanson, J.S.; Diao, J.; De, A.; Sotillo, F.; Harris, G. ); Somasundaran, P.; Harris, C.C.; Vasudevan, T.; Liu, D.; Li, C. ); Hu, W.; Zou, Y.; Chen, W. ); Choudhry, V.; Sehgal, R.; Ghosh, A. (Praxis Engineers, Inc., Milpitas, CA (United Stat

    1991-05-15

    The primary objective in the scope of this research project is to develop advanced flotation methods for coal cleaning in order to achieve near total pyritic-sulfur removal at 90% Btu recovery, using coal samples procured from three major US coal seams. Concomitantly, the ash content of these coals is to be reduced to 6% or less. Investigation of mechanisms for the control of coal and pyrite surfaces prior to fine coal flotation is the main aspect of the project objectives. Research topics covered during this quarter include the characterization of the base coals, various flotation studies on optimization and pyrite rejection, and a detailed flotation kinetic study. The effect of hexanol, butanol, dodecane, and polyethylene glycol on flotation is described. A second major objective is to investigate factors involved in the progressive weathering and oxidation of coal that had been exposed to varying weathered degrees, namely, open, covered and in an argon-inerted'' atmosphere, over a period of twelve months. After regular intervals if weathering, samples of the three base coals (Illinois No. 6, Pittsburgh No. 8 and Upper Freeport PA) were collected and shipped to both the University of Pittsburgh and the University of California at Berkeley for characterization studies of the weathered material. 35 figs., 17 tabs.

  4. Coal surface control for advanced fine coal flotation

    SciTech Connect

    Fuerstenau, D.W.; Sastry, K.V.S.; Hanson, J.S.; Narayanan, K.S.; Sotillo, F.; Diao, J.; Yin, Y.; Harris, G. ); Somasundaran, P.; Harris, C.C.; Vasudevan, T.; Xhong, K.; Xiao, L. ); Hu, Weibai; Zou, Y.; Chen, W. ); Choudhry, V.; Shea, S.; Ghosh, A. (Praxis Engineers, Inc

    1990-02-12

    The primary goal of this research project is to develop advanced flotation methods for coal cleaning in order to achieve 90{percent} pyritic sulfur removal at 90{percent} Btu recovery, using coal samples procured from six major US coal seams. Concomitantly, the ash content of these coals is to be reduced to 6{percent} or less. Investigation of mechanisms for the control of coal and pyrite surfaces prior to fine coal flotation is an important aspect of the project objectives. A second major objective is to investigate factors involved in the progressive weathering and oxidation of three base coals stored in three storage modes, namely, open, covered and in an argon-inerted atmosphere, over a period of twelve months. This quarter results are presented under the following topics: effect of ph modifiers on flotation performance; effect of anionic reagents during grinding; effect of organic monomers; effect of non-ionic reagents; grinding with collector and flotation kinetics; and flotation behavior of weathered coals. (CBS)

  5. Coal surface control for advanced fine coal flotation

    SciTech Connect

    Fuerstenau, D.W.; Sastry, K.V.S.; Hanson, J.S.; Narayanan, K.S.; Urbina, R.H.; Diao, J.; Yin, Y.; Harris, G.; Hu, Weibei; Zou, Y.; Chen, W.; Somasundaran, P.; Harris, C.C.; Vasudevan, T.; Xhong, K.; Xiao, L.; Choudhry, V.; Shea, S.; Ghosh, A.; Sehgal, R.; Utah Univ., Salt Lake City, UT; Columbia Univ., New York, NY; Praxis Engineers, Inc., Milpitas, CA )

    1989-08-15

    The primary goal of this project is to develop advanced flotation methods for coal cleaning in order to achieve 90% pyritic sulfur removal at 90% Btu yield, using coal samples procured from six major US coal seams. Concomitantly, the ash content of these coals is to be reduced to 6% or less. Investigation of mechanisms for the control of coal and pyrite surfaces prior to fine coal flotation is an important aspect of the project objectives. Large quantities of coal samples have been procured from six major seams. Samples of the same coals are also to be supplied to the University of Pittsburgh for selective agglomeration research. A second objective is to investigate factors involved in the progressive weathering and oxidation of coal stored in three storage modes, namely, open, covered and in an argon-inerted atmosphere, over a period of twelve months. After regular intervals of weathering, samples of the three base coals are to be collected and shipped to both the University of Pittsburgh and the University of California at Berkeley for characterization studies of the weathered coals. Work is divided into 8 tasks: (1) project work plan; (2) coal procurement and weathering; (3) coal characterization; (4) standard beneficiation test; (5) grinding studies; (6) surface modification studies; (7) exploratory R D and support; and (8) task integration and project management. 8 refs., 50 figs., 38 tabs.

  6. Coal surface control for advanced fine coal flotation

    SciTech Connect

    Fuerstenau, D.W.; Sastry, K.V.S.; Hanson, J.S.; Harris, G.; Sotillo, F.; Diao, J.; Yin, Y. ); Somasundaran, P.; Harris, C.C.; Vasudevan, T.; Liu, D.; Li, C. ); Hu, Weibai; Zou, Y.; Chen, W. ); Choudhry, V.; Sehgal, R.; Ghosh, A. )

    1990-05-31

    The primary objective in the scope of this research project is to develop advanced flotation methods for coal cleaning in order to achieve near total pyritic sulfur removal at 90% Btu recovery, using coal samples procured from six major US coal seams. The ash content of these coals is to be reduced to 6% or less. Investigation of mechanisms for the control of coal and pyrite surfaces prior to fine coal flotation is an important aspect of the project objectives. A second major objective is to investigate factors involved in the progressive weathering and oxidation of coal that had been exposed to varying weathered degrees, namely, open, covered and in an argon-inerted'' atmosphere, over a period of twelve months. After regular intervals of weathering, samples of the three base coals (Illinois No. 6, Pittsburgh No. 8 and Upper Freeport PA) were collected and shipped to both the University of Pittsburgh and the University of California at Berkeley for characterization studies of the weathered material. Progress is described on weathering, washability studies (calorific value, ash analysis, pyritic sulfur rejection, variability analysis), coal grinding and flotation, pH effects and modification of surfaces on flotation. 26 figs., 20 tabs.

  7. Coal surface control for advanced fine coal flotation

    SciTech Connect

    Fuerstenau, D.W.; Sastry, K.V.S.; Hanson, J.S.; Harris, G.; Sotillo, F.; Diao, J. ); Somasundaran, P.; Harris, C.C.; Vasudevan, T.; Liu, D.; Li, C. ); Hu, Weibai; Zou, Y.; Chen, W. ); Choudhry, V.; Sehgal, R.; Ghosh, A. )

    1990-08-15

    The primary objective of this research project is to develop advanced flotation methods for coal cleaning in order to achieve near total pyritic-sulfur removal at 90% Btu recovery, using coal samples procured from six major US coal seams. Concomitantly, the ash content of these coals is to be reduced to 6% or less. Work this quarter concentrated on the following: washability studies, which included particle size distribution of the washability samples, and chemical analysis of washability test samples; characterization studies of induction time measurements, correlation between yield, combustible-material recovery (CMR), and heating-value recovery (HVR), and QA/QC for standard flotation tests and coal analyses; surface modification and control including testing of surface-modifying reagents, restoration of hydrophobicity to lab-oxidized coals, pH effects on coal flotation, and depression of pyritic sulfur in which pyrite depression with calcium cyanide and pyrite depression with xanthated reagents was investigated; flotation optimization and circuitry included staged reagent addition, cleaning and scavenging, and scavenging and middling recycling. Weathering studies are also discussed. 19 figs., 28 tabs.

  8. Selected advanced aerodynamic and active control concepts development

    NASA Technical Reports Server (NTRS)

    1981-01-01

    A task for the Energy Efficient Transport program conducted: (1) The design and wind tunnel development of high-aspect-ratio supercritical wings, investigating the cruise speed regime and also high-lift. (2) The preliminary design and evaluation of an aircraft combining a high-aspect-ratio supercritical wing with a winglet. (3) Active Controls: The determination of criteria, configuration, and flying qualities associated with augmented longitudinal stability of a level likely to be acceptable for the next generation transport; and the design of a practical augmentation system. The baseline against which the work was performed and evaluated was the Douglas DC-X-200 twin engine derivative of the DC-10 transport. The supercritical wing development showed that the cruise and buffet requirements could be achieved and that the wing could be designed to realize a sizable advantage over today's technology. Important advances in high lift performance were shown. The design study of an aircraft with supercritical wing and winglet suggested advantages in weight and fuel economy could be realized. The study of augmented stability, conducted with the aid of a motion base simulator, concluded that a negative static margin was acceptable for the baseline unaugmented aircraft.

  9. Advanced Guidance and Control for Hypersonics and Space Access

    NASA Technical Reports Server (NTRS)

    Hanson, John M.; Hall, Charles E.; Mulqueen, John A.; Jones, Robert E.

    2003-01-01

    Advanced guidance and control (AG&C) technologies are critical for meeting safety, reliability, and cost requirements for the next generation of reusable launch vehicle (RLV), whether it is fully rocket-powered or has air- breathing components. This becomes clear upon examining the number of expendable launch vehicle failures in the recent past where AG&C technologies could have saved a RLV with the same failure mode, the additional vehicle problems where t h i s technology applies, and the costs and time associated with mission design with or without all these failure issues. The state-of-the-art in guidance and control technology, as well as in computing technology, is the point where we can look to the possibility of being able to safely return a RLV in any situation where it can physically be recovered. This paper outlines reasons for AWC, current technology efforts, and the additional work needed for making this goal a reality. There are a number of approaches to AG&C that have the potential for achieving the desired goals. For some of these methods, we compare the results of tests designed to demonstrate the achievement of the goals. Tests up to now have been focused on rocket-powered vehicles; application to hypersonic air-breathers is planned. We list the test cases used to demonstrate that the desired results are achieved, briefly describe an automated test scoring method, and display results of the tests. Some of the technology components have reached the maturity level where they are ready for application to a new vehicle concept, while others are not far along in development.

  10. Advanced Thermal Control Technologies for "CEV" (New Name: ORION)

    NASA Technical Reports Server (NTRS)

    Golliher, Eric; Westheimer, David; Ewert, Michael; Hasan, Mojib; Anderson, Molly; Tuan, George; Beach, Duane

    2007-01-01

    NASA is currently investigating several technology options for advanced human spaceflight. This presentation covers some recent developments that relate to NASA's Orion spacecraft and future Lunar missions.

  11. Advancing the Theory of Nuclear Reactions with Rare Isotopes: From the Laboratory to the Cosmos

    SciTech Connect

    Elster, Charlotte

    2015-06-01

    The mission of the TORUS Topical Collaboration is to develop new methods that will advance nuclear reaction theory for unstable isotopes by using three-body techniques to improve direct-reaction calculations, and, by using a new partial-fusion theory, to integrate descriptions of direct and compound-nucleus reactions. Ohio University concentrates its efforts on the first part of the mission. Since direct measurements are often not feasible, indirect methods, e.g. (d,p) reactions, should be used. Those (d,p) reactions may be viewed as three-body reactions and described with Faddeev techniques. Faddeev equations in momentum space have a long tradition of utilizing separable interactions in order to arrive at sets of coupled integral equations in one variable. While there exist several separable representations for the nucleon-nucleon interaction, the optical potential between a neutron (proton) and a nucleus is not readily available in separable form. For this reason we first embarked in introducing a separable representation for complex phenomenological optical potentials of Woods-Saxon type.

  12. Advancing Pedagogical Content Knowledge in Communication: A Critical Inquiry into the Ideology of Communication Theory Textbooks.

    ERIC Educational Resources Information Center

    Bedner, Nelle

    A study sought to reveal the ideological structure shaping representations of communication theory in contemporary communication theory textbooks. The characteristics of five communication theory textbooks, including such areas as theory inclusion, theory constitution, and theory presentation, as well as disciplinary issues, the concept of theory…

  13. Advance Noise Control Fan II: Test Rig Fan Risk Management Study

    NASA Technical Reports Server (NTRS)

    Lucero, John

    2013-01-01

    Since 1995 the Advanced Noise Control Fan (ANCF) has significantly contributed to the advancement of the understanding of the physics of fan tonal noise generation. The 9'x15' WT has successfully tested multiple high speed fan designs over the last several decades. This advanced several tone noise reduction concepts to higher TRL and the validation of fan tone noise prediction codes.

  14. The environmental control and life support system advanced automation project

    NASA Technical Reports Server (NTRS)

    Dewberry, Brandon S.

    1991-01-01

    The objective of the ECLSS Advanced Automation project includes reduction of the risk associated with the integration of new, beneficial software techniques. Demonstrations of this software to baseline engineering and test personnel will show the benefits of these techniques. The advanced software will be integrated into ground testing and ground support facilities, familiarizing its usage by key personnel.

  15. The role of modern control theory in the design of controls for aircraft turbine engines

    NASA Technical Reports Server (NTRS)

    Zeller, J.; Lehtinen, B.; Merrill, W.

    1982-01-01

    The development, applications, and current research in modern control theory (MCT) are reviewed, noting the importance for fuel-efficient operation of turbines with variable inlet guide vanes, compressor stators, and exhaust nozzle area. The evolution of multivariable propulsion control design is examined, noting a basis in a matrix formulation of the differential equations defining the process, leading to state space formulations. Reports and papers which appeared from 1970-1982 which dealt with problems in MCT applications to turbine engine control design are outlined, including works on linear quadratic regulator methods, frequency domain methods, identification, estimation, and model reduction, detection, isolation, and accommodation, and state space control, adaptive control, and optimization approaches. Finally, NASA programs in frequency domain design, sensor failure detection, computer-aided control design, and plant modeling are explored

  16. Application of modern control theory to the design of optimum aircraft controllers

    NASA Technical Reports Server (NTRS)

    Power, L. J.

    1973-01-01

    A procedure is described for synthesis of optimal aircraft control systems by application of the concepts of optimal control theory to time-invariant linear systems with quadratic performance criteria. Essential in this synthesis procedure is the solution of the Riccati matrix equation which results in a constant linear feedback control law for an output regulator which maintains a plant in an equilibrium in the presence of impulse disturbances. An algorithm is derived for designing maneuverable output regulators with selected state variables for feedback.

  17. Project Management Using Modern Guidance, Navigation and Control Theory

    NASA Technical Reports Server (NTRS)

    Hill, Terry R.

    2011-01-01

    Implementing guidance, navigation, and control (GN&C) theory principles and applying them to the human element of project management and control is not a new concept. As both the literature on the subject and the real-world applications are neither readily available nor comprehensive with regard to how such principles might be applied, this paper has been written to educate the project manager on the "laws of physics" of his or her project (not to teach a GN&C engineer how to become a project manager) and to provide an intuitive, mathematical explanation as to the control and behavior of projects. This paper will also address how the fundamental principles of modern GN&C were applied to the National Aeronautics and Space Administration's (NASA) Constellation Program (CxP) space suit project, ensuring the project was managed within cost, schedule, and budget. A project that is akin to a physical system can be modeled and managed using the same over arching principles of GN&C that would be used if that project were a complex vehicle, a complex system(s), or complex software with time-varying processes (at times nonlinear) containing multiple data inputs of varying accuracy and a range of operating points. The classic GN&C theory approach could thus be applied to small, well-defined projects; yet when working with larger, multiyear projects necessitating multiple organizational structures, numerous external influences, and a multitude of diverse resources, modern GN&C principles are required to model and manage the project. The fundamental principles of a GN&C system incorporate these basic concepts: State, Behavior, Feedback Control, Navigation, Guidance and Planning Logic systems. The State of a system defines the aspects of the system that can change over time; e.g., position, velocity, acceleration, coordinate-based attitude, and temperature, etc. The Behavior of the system focuses more on what changes are possible within the system; this is denoted in the state

  18. Advanced Control Surface Seal Development for Future Space Vehicles

    NASA Technical Reports Server (NTRS)

    DeMange, J. J.; Dunlap, P. H., Jr.; Steinetz, B. M.

    2004-01-01

    NASA s Glenn Research Center (GRC) has been developing advanced high temperature structural seals since the late 1980's and is currently developing seals for future space vehicles as part of the Next Generation Launch Technology (NGLT) program. This includes control surface seals that seal the edges and hinge lines of movable flaps and elevons on future reentry vehicles. In these applications, the seals must operate at temperatures above 2000 F in an oxidizing environment, limit hot gas leakage to protect underlying structures, endure high temperature scrubbing against rough surfaces, and remain flexible and resilient enough to stay in contact with sealing surfaces for multiple heating and loading cycles. For this study, three seal designs were compared against the baseline spring tube seal through a series of compression tests at room temperature and 2000 F and flow tests at room temperature. In addition, canted coil springs were tested as preloaders behind the seals at room temperature to assess their potential for improving resiliency. Addition of these preloader elements resulted in significant increases in resiliency compared to the seals by themselves and surpassed the performance of the baseline seal at room temperature. Flow tests demonstrated that the seal candidates with engineered cores had lower leakage rates than the baseline spring tube design. However, when the seals were placed on the preloader elements, the flow rates were higher as the seals were not compressed as much and therefore were not able to fill the groove as well. High temperature tests were also conducted to asses the compatibility of seal fabrics against ceramic matrix composite (CMC) panels anticipated for use in next generation launch vehicles. These evaluations demonstrated potential bonding issues between the Nextel fabrics and CMC candidates.

  19. Advanced Control Surface Seal Development for Future Space Vehicles

    NASA Technical Reports Server (NTRS)

    DeMange, Jeffrey J.; Dunlap, Patrick H.; Steinetz, Bruce M.

    2003-01-01

    NASA's Glenn Research Center (GRC) has been developing advanced high temperature structural seals since the late 1980s and is currently developing seals for future space vehicles as part of the Next Generation Launch Technology (NGLT) program. This includes control surface seals that seal the edges and hinge lines of movable flaps and elevons on future reentry vehicles. In these applications, the seals must operate at temperatures above 2000 F in an oxidizing environment, limit hot gas leakage to protect underlying structures, endure high temperature scrubbing against rough surfaces, and remain flexible and resilient enough to stay in contact with sealing surfaces for multiple heating and loading cycles. For this study, three seal designs were compared against the baseline spring tube seal through a series of compression tests at room temperature and 2000 F and flow tests at room temperature. In addition, canted coil springs were tested as preloaders behind the seals at room temperature to assess their potential for improving resiliency. Addition of these preloader elements resulted in significant increases in resiliency compared to seals by themselves and surpassed the performance of the baseline seal at room temperature. Flow tests demonstrated that the seal candidates with engineered cores had lower leakage rates than the baseline spring tube design. However, then the seals were placed on the preloader elements, the flow rates were higher as the seals were not compressed as much and therefore were not able to fill the groove as well. High temperature tests were also conducted to assess the compatability of seal fabrics against cermaic matrix composite (CMC) panels anticipated for use in next generation launch vehicles. These evaluations demonstrated potential bonding issues between the Nextel fabrics and CMC candidates.

  20. Optimal control of ICU patient discharge: from theory to implementation.

    PubMed

    Mallor, Fermín; Azcárate, Cristina; Barado, Julio

    2015-09-01

    This paper deals with the management of scarce health care resources. We consider a control problem in which the objective is to minimize the rate of patient rejection due to service saturation. The scope of decisions is limited, in terms both of the amount of resources to be used, which are supposed to be fixed, and of the patient arrival pattern, which is assumed to be uncontrollable. This means that the only potential areas of control are speed or completeness of service. By means of queuing theory and optimization techniques, we provide a theoretical solution expressed in terms of service rates. In order to make this theoretical analysis useful for the effective control of the healthcare system, however, further steps in the analysis of the solution are required: physicians need flexible and medically-meaningful operative rules for shortening patient length of service to the degree needed to give the service rates dictated by the theoretical analysis. The main contribution of this paper is to discuss how the theoretical solutions can be transformed into effective management rules to guide doctors' decisions. The study examines three types of rules based on intuitive interpretations of the theoretical solution. Rules are evaluated through implementation in a simulation model. We compare the service rates provided by the different policies with those dictated by the theoretical solution. Probabilistic analysis is also included to support rule validity. An Intensive Care Unit is used to illustrate this control problem. The study focuses on the Markovian case before moving on to consider more realistic LoS distributions (Weibull, Lognormal and Phase-type distribution). PMID:25763761

  1. PARTICULATE CONTROL HIGHLIGHTS: ADVANCED CONCEPTS IN ELECTROSTATIC PRECIPITATORS: PARTICLE CHARGING

    EPA Science Inventory

    The report gives highlights of an EPA research program aimed at developing and verifying an accurate theory of particle charging for conditions that are typically found in industrial electrostatic precipitators. A new theory was developed, in which the thermal motion of ions is a...

  2. Advances in numerical solutions to integral equations in liquid state theory

    NASA Astrophysics Data System (ADS)

    Howard, Jesse J.

    Solvent effects play a vital role in the accurate description of the free energy profile for solution phase chemical and structural processes. The inclusion of solvent effects in any meaningful theoretical model however, has proven to be a formidable task. Generally, methods involving Poisson-Boltzmann (PB) theory and molecular dynamic (MD) simulations are used, but they either fail to accurately describe the solvent effects or require an exhaustive computation effort to overcome sampling problems. An alternative to these methods are the integral equations (IEs) of liquid state theory which have become more widely applicable due to recent advancements in the theory of interaction site fluids and the numerical methods to solve the equations. In this work a new numerical method is developed based on a Newton-type scheme coupled with Picard/MDIIS routines. To extend the range of these numerical methods to large-scale data systems, the size of the Jacobian is reduced using basis functions, and the Newton steps are calculated using a GMRes solver. The method is then applied to calculate solutions to the 3D reference interaction site model (RISM) IEs of statistical mechanics, which are derived from first principles, for a solute model of a pair of parallel graphene plates at various separations in pure water. The 3D IEs are then extended to electrostatic models using an exact treatment of the long-range Coulomb interactions for negatively charged walls and DNA duplexes in aqueous electrolyte solutions to calculate the density profiles and solution thermodynamics. It is found that the 3D-IEs provide a qualitative description of the density distributions of the solvent species when compared to MD results, but at a much reduced computational effort in comparison to MD simulations. The thermodynamics of the solvated systems are also qualitatively reproduced by the IE results. The findings of this work show the IEs to be a valuable tool for the study and prediction of

  3. Application of Percolation Theory to Complex Interconnected Networks in Advanced Functional Composites

    NASA Astrophysics Data System (ADS)

    Hing, P.

    2011-11-01

    Percolation theory deals with the behaviour of connected clusters in a system. Originally developed for studying the flow of liquid in a porous body, the percolation theory has been extended to quantum computation and communication, entanglement percolation in quantum networks, cosmology, chaotic situations, properties of disordered solids, pandemics, petroleum industry, finance, control of traffic and so on. In this paper, the application of various models of the percolation theory to predict and explain the properties of a specially developed family of dense sintered and highly refractory Al2O3-W composites for potential application in high intensity discharge light sources such as high pressure sodium lamps and ceramic metal halide lamps are presented and discussed. The low cost, core-shell concept can be extended to develop functional composite materials with unusual dielectric, electrical, magnetic, superconducting, and piezoelectric properties starting from a classical insulator. The core shell concept can also be applied to develop catalysts with high specific surface areas with minimal amount of expensive platinium, palladium or rare earth nano structured materials for light harvesting, replicating natural photosynthesis, in synthetic zeolite composites for the cracking and separation of crude oil. There is also possibility of developing micron and nanosize Faraday cages for quantum devices, nano electronics and spintronics. The possibilities are limitless.

  4. Advanced Sensors and Controls for Building Applications: Market Assessment and Potential R&D Pathways

    SciTech Connect

    Brambley, M. R.; Haves, P.; McDonald, S. C.; Torcellini, P.; Hansen, D.; Holmberg, D. R.; Roth, K. W.

    2005-04-01

    This document provides a market assessment of existing building sensors and controls and presents a range of technology pathways (R&D options) for pursuing advanced sensors and building control strategies.

  5. Advanced Diagnostics and Control for Furnaces, Fired Heaters and Boilers

    SciTech Connect

    2007-06-01

    This factsheet describes a research project whose objective is to develop and implement technologies that address advanced combustion diagnostics and rapid Btu measurements of fuels. These are the fundamental weaknesses associated with the combustion processes of a furnace.

  6. Integrated Application of Active Controls (IAAC) technology to an advanced subsonic transport project: Current and advanced act control system definition study. Volume 2: Appendices

    NASA Technical Reports Server (NTRS)

    Hanks, G. W.; Shomber, H. A.; Dethman, H. A.; Gratzer, L. B.; Maeshiro, A.; Gangsaas, D.; Blight, J. D.; Buchan, S. M.; Crumb, C. B.; Dorwart, R. J.

    1981-01-01

    The current status of the Active Controls Technology (ACT) for the advanced subsonic transport project is investigated through analysis of the systems technical data. Control systems technologies under examination include computerized reliability analysis, pitch axis fly by wire actuator, flaperon actuation system design trade study, control law synthesis and analysis, flutter mode control and gust load alleviation analysis, and implementation of alternative ACT systems. Extensive analysis of the computer techniques involved in each system is included.

  7. Physical control oriented model of large scale refrigerators to synthesize advanced control schemes. Design, validation, and first control results

    NASA Astrophysics Data System (ADS)

    Bonne, François; Alamir, Mazen; Bonnay, Patrick

    2014-01-01

    In this paper, a physical method to obtain control-oriented dynamical models of large scale cryogenic refrigerators is proposed, in order to synthesize model-based advanced control schemes. These schemes aim to replace classical user experience designed approaches usually based on many independent PI controllers. This is particularly useful in the case where cryoplants are submitted to large pulsed thermal loads, expected to take place in the cryogenic cooling systems of future fusion reactors such as the International Thermonuclear Experimental Reactor (ITER) or the Japan Torus-60 Super Advanced Fusion Experiment (JT-60SA). Advanced control schemes lead to a better perturbation immunity and rejection, to offer a safer utilization of cryoplants. The paper gives details on how basic components used in the field of large scale helium refrigeration (especially those present on the 400W @1.8K helium test facility at CEA-Grenoble) are modeled and assembled to obtain the complete dynamic description of controllable subsystems of the refrigerator (controllable subsystems are namely the Joule-Thompson Cycle, the Brayton Cycle, the Liquid Nitrogen Precooling Unit and the Warm Compression Station). The complete 400W @1.8K (in the 400W @4.4K configuration) helium test facility model is then validated against experimental data and the optimal control of both the Joule-Thompson valve and the turbine valve is proposed, to stabilize the plant under highly variable thermals loads. This work is partially supported through the European Fusion Development Agreement (EFDA) Goal Oriented Training Program, task agreement WP10-GOT-GIRO.

  8. Physical control oriented model of large scale refrigerators to synthesize advanced control schemes. Design, validation, and first control results

    SciTech Connect

    Bonne, François; Bonnay, Patrick

    2014-01-29

    In this paper, a physical method to obtain control-oriented dynamical models of large scale cryogenic refrigerators is proposed, in order to synthesize model-based advanced control schemes. These schemes aim to replace classical user experience designed approaches usually based on many independent PI controllers. This is particularly useful in the case where cryoplants are submitted to large pulsed thermal loads, expected to take place in the cryogenic cooling systems of future fusion reactors such as the International Thermonuclear Experimental Reactor (ITER) or the Japan Torus-60 Super Advanced Fusion Experiment (JT-60SA). Advanced control schemes lead to a better perturbation immunity and rejection, to offer a safer utilization of cryoplants. The paper gives details on how basic components used in the field of large scale helium refrigeration (especially those present on the 400W @1.8K helium test facility at CEA-Grenoble) are modeled and assembled to obtain the complete dynamic description of controllable subsystems of the refrigerator (controllable subsystems are namely the Joule-Thompson Cycle, the Brayton Cycle, the Liquid Nitrogen Precooling Unit and the Warm Compression Station). The complete 400W @1.8K (in the 400W @4.4K configuration) helium test facility model is then validated against experimental data and the optimal control of both the Joule-Thompson valve and the turbine valve is proposed, to stabilize the plant under highly variable thermals loads. This work is partially supported through the European Fusion Development Agreement (EFDA) Goal Oriented Training Program, task agreement WP10-GOT-GIRO.

  9. Designing and Testing Contols to Mitigate Dynamic Loads in the Controls Advanced Research Turbine: Preprint

    SciTech Connect

    Wright, A.D.; Stol, K.A.

    2008-01-01

    The National Renewable Energy Laboratory is designing, implementing, and testing advanced controls to maximize energy extraction and reduce structural dynamic loads of wind turbines. These control designs are based on a linear model of the turbine that is generated by specialized modeling software. In this paper, we show the design and simulation testing of a control algorithm to mitigate blade, tower, and drivetrain loads using advanced state-space control design methods.

  10. The Advanced Composition Explorer Shock Database and Application to Particle Acceleration Theory

    NASA Technical Reports Server (NTRS)

    Parker, L. Neergaard; Zank, G. P.

    2015-01-01

    The theory of particle acceleration via diffusive shock acceleration (DSA) has been studied in depth by Gosling et al. (1981), van Nes et al. (1984), Mason (2000), Desai et al. (2003), Zank et al. (2006), among many others. Recently, Parker and Zank (2012, 2014) and Parker et al. (2014) using the Advanced Composition Explorer (ACE) shock database at 1 AU explored two questions: does the upstream distribution alone have enough particles to account for the accelerated downstream distribution and can the slope of the downstream accelerated spectrum be explained using DSA? As was shown in this research, diffusive shock acceleration can account for a large population of the shocks. However, Parker and Zank (2012, 2014) and Parker et al. (2014) used a subset of the larger ACE database. Recently, work has successfully been completed that allows for the entire ACE database to be considered in a larger statistical analysis. We explain DSA as it applies to single and multiple shocks and the shock criteria used in this statistical analysis. We calculate the expected injection energy via diffusive shock acceleration given upstream parameters defined from the ACE Solar Wind Electron, Proton, and Alpha Monitor (SWEPAM) data to construct the theoretical upstream distribution. We show the comparison of shock strength derived from diffusive shock acceleration theory to observations in the 50 keV to 5 MeV range from an instrument on ACE. Parameters such as shock velocity, shock obliquity, particle number, and time between shocks are considered. This study is further divided into single and multiple shock categories, with an additional emphasis on forward-forward multiple shock pairs. Finally with regard to forwardforward shock pairs, results comparing injection energies of the first shock, second shock, and second shock with previous energetic population will be given.

  11. The Advanced Composition Explorer Shock Database and Application to Particle Acceleration Theory

    NASA Technical Reports Server (NTRS)

    Parker, L. Neergaard; Zank, G. P.

    2015-01-01

    The theory of particle acceleration via diffusive shock acceleration (DSA) has been studied in depth by Gosling et al. (1981), van Nes et al. (1984), Mason (2000), Desai et al. (2003), Zank et al. (2006), among many others. Recently, Parker and Zank (2012, 2014) and Parker et al. (2014) using the Advanced Composition Explorer (ACE) shock database at 1 AU explored two questions: does the upstream distribution alone have enough particles to account for the accelerated downstream distribution and can the slope of the downstream accelerated spectrum be explained using DSA? As was shown in this research, diffusive shock acceleration can account for a large population of the shocks. However, Parker and Zank (2012, 2014) and Parker et al. (2014) used a subset of the larger ACE database. Recently, work has successfully been completed that allows for the entire ACE database to be considered in a larger statistical analysis. We explain DSA as it applies to single and multiple shocks and the shock criteria used in this statistical analysis. We calculate the expected injection energy via diffusive shock acceleration given upstream parameters defined from the ACE Solar Wind Electron, Proton, and Alpha Monitor (SWEPAM) data to construct the theoretical upstream distribution. We show the comparison of shock strength derived from diffusive shock acceleration theory to observations in the 50 keV to 5 MeV range from an instrument on ACE. Parameters such as shock velocity, shock obliquity, particle number, and time between shocks are considered. This study is further divided into single and multiple shock categories, with an additional emphasis on forward-forward multiple shock pairs. Finally with regard to forward-forward shock pairs, results comparing injection energies of the first shock, second shock, and second shock with previous energetic population will be given.

  12. Dynamic Event Tree advancements and control logic improvements

    SciTech Connect

    Alfonsi, Andrea; Rabiti, Cristian; Mandelli, Diego; Sen, Ramazan Sonat; Cogliati, Joshua Joseph

    2015-09-01

    The RAVEN code has been under development at the Idaho National Laboratory since 2012. Its main goal is to create a multi-purpose platform for the deploying of all the capabilities needed for Probabilistic Risk Assessment, uncertainty quantification, data mining analysis and optimization studies. RAVEN is currently equipped with three different sampling categories: Forward samplers (Monte Carlo, Latin Hyper Cube, Stratified, Grid Sampler, Factorials, etc.), Adaptive Samplers (Limit Surface search, Adaptive Polynomial Chaos, etc.) and Dynamic Event Tree (DET) samplers (Deterministic and Adaptive Dynamic Event Trees). The main subject of this document is to report the activities that have been done in order to: start the migration of the RAVEN/RELAP-7 control logic system into MOOSE, and develop advanced dynamic sampling capabilities based on the Dynamic Event Tree approach. In order to provide to all MOOSE-based applications a control logic capability, in this Fiscal Year an initial migration activity has been initiated, moving the control logic system, designed for RELAP-7 by the RAVEN team, into the MOOSE framework. In this document, a brief explanation of what has been done is going to be reported. The second and most important subject of this report is about the development of a Dynamic Event Tree (DET) sampler named “Hybrid Dynamic Event Tree” (HDET) and its Adaptive variant “Adaptive Hybrid Dynamic Event Tree” (AHDET). As other authors have already reported, among the different types of uncertainties, it is possible to discern two principle types: aleatory and epistemic uncertainties. The classical Dynamic Event Tree is in charge of treating the first class (aleatory) uncertainties; the dependence of the probabilistic risk assessment and analysis on the epistemic uncertainties are treated by an initial Monte Carlo sampling (MCDET). From each Monte Carlo sample, a DET analysis is run (in total, N trees). The Monte Carlo employs a pre-sampling of the

  13. An examination of network position and childhood relational aggression: integrating resource control and social exchange theories.

    PubMed

    Neal, Jennifer Watling; Cappella, Elise

    2012-01-01

    Applying resource control theory and social exchange theory, we examined the social network conditions under which elementary age children were likely to engage in relational aggression. Data on classroom peer networks and peer-nominated behaviors were collected on 671 second- through fourth-grade children in 34 urban, low-income classrooms. Nested regression models with robust cluster standard errors demonstrated that the association between children's number of relationships and their levels of relational aggression was moderated by the number of relationships that their affiliates had. Children with more peer relationships (i.e., higher network centrality) exhibited higher levels of relational aggression, but only when these relationships were with peers who had fewer connections themselves (i.e., poorly connected peers). This finding remained significant even when controlling for common predictors of relational aggression including gender, overt aggression, prosocial behavior, victimization, social preference, and perceived popularity. Results are discussed in terms of their implications for advancing the literature on childhood relational aggression and their practical applications for identifying children at risk for these behaviors. PMID:25363638

  14. Advances in Educational and Psychological Testing: Theory and Applications. Evaluation in Education and Human Services Series.

    ERIC Educational Resources Information Center

    Hambleton, Ronald K., Ed.; Zaal, Jac N., Ed.

    The 14 chapters of this book focus on the technical advances, advances in applied settings, and emerging topics in the testing field. Part 1 discusses methodological advances, Part 2 considers developments in applied settings, and Part 3 reviews emerging topics in the field of testing. Part 1 papers include: (1) "Advances in Criterion-Referenced…

  15. Field Testing LIDAR Based Feed-Forward Controls on the NREL Controls Advanced Research Turbine: Preprint

    SciTech Connect

    Scholbrock, A. K.; Fleming, P. A.; Fingersh, L. J.; Wright, A. D.; Schlipf, D.; Haizmann, F.; Belen, F.

    2013-01-01

    Wind turbines are complex, nonlinear, dynamic systems driven by aerodynamic, gravitational, centrifugal, and gyroscopic forces. The aerodynamics of wind turbines are nonlinear, unsteady, and complex. Turbine rotors are subjected to a chaotic three-dimensional (3-D) turbulent wind inflow field with imbedded coherent vortices that drive fatigue loads and reduce lifetime. In order to reduce cost of energy, future large multimegawatt turbines must be designed with lighter weight structures, using active controls to mitigate fatigue loads, maximize energy capture, and add active damping to maintain stability for these dynamically active structures operating in a complex environment. Researchers at the National Renewable Energy Laboratory (NREL) and University of Stuttgart are designing, implementing, and testing advanced feed-back and feed-forward controls in order to reduce the cost of energy for wind turbines.

  16. Urban ecology in a developing world: why advanced socioecological theory needs Africa

    PubMed Central

    Bunn, David N; Pickett, Steward TA; Twine, Wayne

    2014-01-01

    Socioecological theory, developed through the study of urban environments, has recently led to a proliferation of research focusing on comparative analyses of cities. This research emphasis has been concentrated in the more developed countries of the Northern Hemisphere (often referred to as the “Global North”), yet urbanization is now occurring mostly in the developing world, with the fastest rates of growth in sub-Saharan Africa. Countries like South Africa are experiencing a variety of land-cover changes that may challenge current assumptions about the differences between urban and rural environments and about the connectivity of these dynamic socioecological systems. Furthermore, questions concerning ecosystem services, landscape preferences, and conservation – when analyzed through rural livelihood frameworks – may provide insights into the social and ecological resilience of human settlements. Increasing research on urban development processes occurring in Africa, and on patterns of kinship and migration in the less developed countries of the “Global South”, will advance a more comprehensive worldview of how future urbanization will influence the progress of sustainable societies. PMID:24891843

  17. Urban ecology in a developing world: why advanced socioecological theory needs Africa.

    PubMed

    McHale, Melissa R; Bunn, David N; Pickett, Steward Ta; Twine, Wayne

    2013-12-01

    Socioecological theory, developed through the study of urban environments, has recently led to a proliferation of research focusing on comparative analyses of cities. This research emphasis has been concentrated in the more developed countries of the Northern Hemisphere (often referred to as the "Global North"), yet urbanization is now occurring mostly in the developing world, with the fastest rates of growth in sub-Saharan Africa. Countries like South Africa are experiencing a variety of land-cover changes that may challenge current assumptions about the differences between urban and rural environments and about the connectivity of these dynamic socioecological systems. Furthermore, questions concerning ecosystem services, landscape preferences, and conservation - when analyzed through rural livelihood frameworks - may provide insights into the social and ecological resilience of human settlements. Increasing research on urban development processes occurring in Africa, and on patterns of kinship and migration in the less developed countries of the "Global South", will advance a more comprehensive worldview of how future urbanization will influence the progress of sustainable societies. PMID:24891843

  18. Advances in the diagnosis and control of lymphomas.

    PubMed

    Candelaria, Myrna

    2016-04-01

    Lymphoproliferative disorders have increased in last decades. Immunohistochemistry analysis is required to categorize them in different clinical entities, as has been stablished by WHO. Advances in imaging have set the PET-CT as a standard staging procedure in most cases. Knowledge of the biology of these malignancies has allowed therapeutic advances with different approaches, including development of monoclonal antibodies, conjugated antibodies, immunomodulatory agents, as well as inhibition of specific pathways. Although new drugs are promising, the cost-benefit impact requires to be evaluated in pharmacoeconomic clinical trials. PMID:27557389

  19. Recent advances in shell theory. [application of asymptotic approach to thin walled shells

    NASA Technical Reports Server (NTRS)

    Simmonds, J. G.

    1976-01-01

    The results reviewed are divided into two categories: those that relate two-dimensional shell theory to three-dimensional elasticity theory and those concerned with shell theory per se. In the second category results for general elastic systems that carry over, by specialization or analogy, to shells and results that are unique to shell theory itself are considered.

  20. Some remarks on the current status of the control theory of single space dimension hyperbolic systems

    NASA Technical Reports Server (NTRS)

    Russell, D. L.

    1983-01-01

    Various aspects of the control theory of hyperbolic systems, including controllability, stabilization, control canonical form theory, etc., are reviewed. To allow a unified and not excessively technical treatment, attention is restricted to the case of a single space variable. A newly developed procedure of canonical augmentation is discussed.

  1. Rough-Wall Channel Analysis Using Suboptimal Control Theory

    NASA Technical Reports Server (NTRS)

    Flores, O.; Jimenez, J.; Tenpleton, J.

    2003-01-01

    The original aim of this work was to shed some light on the physics of turbulence over rough walls using large-eddy simulations and the suboptimal-control wall boundary conditions introduced by Nicoud et al. It was hoped that, if that algorithm was used to fit the mean velocity profile of the simulations to that of a rough-walled channel, instead of to a smooth one, the wall stresses introduced by the control algorithm would give some indication of what aspects of rough walls are most responsible for the modification of the flow in real turbulence. It was similarly expected that the structure of the resulting velocity fluctuations would share some of the characteristics of rough-walled flows, thus again suggesting what is intrinsic and what is accidental in the effect of geometric wall roughness. A secondary goal was to study the effect of 'unphysical' boundary conditions on the outside flow by observing how a relatively major change of the target velocity profile, and therefore presumably of the applied wall stresses, modifies properties such as the dominant length scales of the velocity fluctuations away from the wall. As will be seen below, this secondary goal grew more important during the course of the study, which was carried out during a short summer visit of the first two authors to the CTR. It became clear that there are open questions about the way in which the control algorithm models the boundary conditions, even for smooth walls, and that these questions make the physical interpretation of the results difficult. Considerable more work in that area seems to be needed before even relatively advanced large-eddy simulations, such as these, can be used to draw conclusions about the physics of wall-bounded turbulent flows. The numerical method is the same as in Nicoud et al. The modifications introduced in the original code are briefly described in section 2, but the original paper should be consulted for a full description of the algorithm. The results are

  2. Advanced technology for controlling pollutant emissions from supersonic cruise aircraft

    NASA Technical Reports Server (NTRS)

    Duerr, R. A.; Diehl, L. A.

    1980-01-01

    Gas turbine engine combustor technology for the reduction of pollutant emissions is summarized. Variations of conventional combustion systems and advanced combustor concepts are discussed. Projected results from far term technology efforts aimed at applying the premixed prevaporized and catalytic combustion techniques to aircraft combustion systems indicate a potential for significant reductions in pollutant emission levels.

  3. Field testing of linear individual pitch control on the two-bladed controls advanced research turbine

    SciTech Connect

    van Solingen, Edwin; Fleming, Paul A.; Scholbrock, Andrew; van Wingerden, Jan-Willem

    2015-04-17

    This paper presents the results of field tests using linear individual pitch control (LIPC) on the two-bladed Controls Advanced Research Turbine 2 (CART2) at the National Renewable Energy Laboratory (NREL). LIPC has recently been introduced as an alternative to the conventional individual pitch control (IPC) strategy for two-bladed wind turbines. The main advantage of LIPC over conventional IPC is that it requires, at most, only two feedback loops to potentially reduce the periodic blade loads. In previous work, LIPC was designed to implement blade pitch angles at a fixed frequency (e.g., the once-per-revolution (1P) frequency), which made it only applicable in above-rated wind turbine operating conditions. In this study, LIPC is extended to below-rated operating conditions by gain scheduling the controller on the rotor speed. With this extension, LIPC and conventional IPC are successfully applied to the NREL CART2 wind turbine. Lastly, the field-test results obtained during the measurement campaign indicate that LIPC significantly reduces the wind turbine loads for both below-rated and above-rated operation.

  4. Field testing of linear individual pitch control on the two-bladed controls advanced research turbine

    DOE PAGESBeta

    van Solingen, Edwin; Fleming, Paul A.; Scholbrock, Andrew; van Wingerden, Jan-Willem

    2015-04-17

    This paper presents the results of field tests using linear individual pitch control (LIPC) on the two-bladed Controls Advanced Research Turbine 2 (CART2) at the National Renewable Energy Laboratory (NREL). LIPC has recently been introduced as an alternative to the conventional individual pitch control (IPC) strategy for two-bladed wind turbines. The main advantage of LIPC over conventional IPC is that it requires, at most, only two feedback loops to potentially reduce the periodic blade loads. In previous work, LIPC was designed to implement blade pitch angles at a fixed frequency (e.g., the once-per-revolution (1P) frequency), which made it only applicablemore » in above-rated wind turbine operating conditions. In this study, LIPC is extended to below-rated operating conditions by gain scheduling the controller on the rotor speed. With this extension, LIPC and conventional IPC are successfully applied to the NREL CART2 wind turbine. Lastly, the field-test results obtained during the measurement campaign indicate that LIPC significantly reduces the wind turbine loads for both below-rated and above-rated operation.« less

  5. Implicit theories about willpower predict the activation of a rest goal following self-control exertion.

    PubMed

    Job, Veronika; Bernecker, Katharina; Miketta, Stefanie; Friese, Malte

    2015-10-01

    Past research indicates that peoples' implicit theories about the nature of willpower moderate the ego-depletion effect. Only people who believe or were led to believe that willpower is a limited resource (limited-resource theory) showed lower self-control performance after an initial demanding task. As of yet, the underlying processes explaining this moderating effect by theories about willpower remain unknown. Here, we propose that the exertion of self-control activates the goal to preserve and replenish mental resources (rest goal) in people with a limited-resource theory. Five studies tested this hypothesis. In Study 1, individual differences in implicit theories about willpower predicted increased accessibility of a rest goal after self-control exertion. Furthermore, measured (Study 2) and manipulated (Study 3) willpower theories predicted an increased preference for rest-conducive objects. Finally, Studies 4 and 5 provide evidence that theories about willpower predict actual resting behavior: In Study 4, participants who held a limited-resource theory took a longer break following self-control exertion than participants with a nonlimited-resource theory. Longer resting time predicted decreased rest goal accessibility afterward. In Study 5, participants with an induced limited-resource theory sat longer on chairs in an ostensible product-testing task when they had engaged in a task requiring self-control beforehand. This research provides consistent support for a motivational shift toward rest after self-control exertion in people holding a limited-resource theory about willpower. PMID:26075793

  6. Integrated controls/structures study of advanced space systems

    NASA Technical Reports Server (NTRS)

    Greene, C. S.; Cunningham, T. B.

    1982-01-01

    A cost tradeoff is postulated for a stiff structure utilizing minimal controls (and control expense) to point and stabilize the vehicle. Extra costs for a stiff structure are caused by weight, packaging size, etc. Likewise, a more flexible vehicle should result in reduced structural costs but increased costs associated with additional control hardware and data processing required for vibration control of the structure. This tradeoff occurs as the ratio of the control bandwidth required for the mission to the lowest (significant) bending mode of the vehicle. The cost of controlling a spacecraft for a specific mission and the same basic configuration but varying the flexibility is established.

  7. Ultrasonic Testing, Aviation Quality Control (Advanced): 9227.03.

    ERIC Educational Resources Information Center

    Dade County Public Schools, Miami, FL.

    This unit of instruction covers the theory of ultrasonic sound, methods of applying soundwaves to test specimens and interpreting results, calibrating the ultrasonic equipment, and the use of standards. Study periods, group discussions, and extensive use of textbooks and training manuals are to be used. These are listed along with references and…

  8. O the Use of Modern Control Theory for Active Structural Acoustic Control.

    NASA Astrophysics Data System (ADS)

    Saunders, William Richard

    A modern control theory formulation of Active Structural Acoustic Control (ASAC) of simple structures radiating acoustic energy into light or heavy fluid mediums is discussed in this dissertation. ASAC of a baffled, simply-supported plate subject to mechanical disturbances is investigated. For the case of light fluid loading, a finite element modelling approach is used to extend previous ASAC design methods. Vibration and acoustic controllers are designed for the plate. Comparison of the controller performance shows distinct advantages of the ASAC method for minimizing radiated acoustic power. A novel approach to the modelling of the heavy fluid-loaded plate is developed here. Augmenting structural and acoustic dynamics using state vector formalism allows the design of both vibration and ASAC controllers for the fluid-loaded plate. This modern control approach to active structural acoustic control is unique in its ability to suppress both persistent and transient disturbances on a plate in a heavy fluid. Numerical simulations of the open-loop and closed-loop plate response are provided to support the theoretical developments.

  9. Modeling and Advanced Control for Sustainable Process Systems (chapter 5)

    EPA Science Inventory

    This book chapter introduces a novel process systems engineering framework that integrates process control with sustainability assessment tools for the simultaneous evaluation and optimization of process operations. The implemented control strategy consists of a biologically-insp...

  10. Advances in microbial insect control in horticultural ecosystems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The use of microbial organisms as biological control agents has progressed significantly since Metschnikoff launched the first attempt at microbial insect control with Metarhizium anisopliae in 1879. Following the lead of Metschnikoff, entomopathogenic nematodes, fungi, bacteria and viruses have b...

  11. Thermochemistry of Aqueous Hydroxyl Radical from Advances in Photoacoustic Calorimetry and ab Initio Continum Solvation Theory

    SciTech Connect

    Autrey, Thomas; Brown, Aaron K.; Camaioni, Donald M.; Dupuis, Michel; Foster, Nancy S.; Getty, April D.

    2004-03-31

    Photoacoustic signals from dilute ({approx}30 mM) solutions of H{sub 2}O{sub 2} were measured over the temperature range from 10-45 C to obtain the reaction enthalpy and volume change for H{sub 2}O{sub 2}(aq) {yields} 2 OH(aq) from which we ultimately determined {Delta}{sub f}G{sup o}, {Delta}{sub f}H{sup o} and partial molal volume, v{sup o}, of OH (aq). We find {Delta}{sub r}H = 46.8 {+-} 1.4 kcal/mol, which is 4 kcal/mol smaller than the gas phase bond energy, and {Delta}V{sub r} = 6.5 {+-} 0.4 mL/mol. The v{sup o} for OH in water is 14.4 {+-} 0.4 mL/ml: smaller than the v{sup o} of water. Using ab initio continuum theory, the hydration free energy is calculated to be -3.9 {+-} 0.3 kcal/mol (for standard states in number density concentration units) by a novel approach devised to capture in the definition of the solute cavity the strength and specific interactions of the solute with a water solvent molecule. The shape of the cavity is defined by ''rolling'' a 3 dimensional electron density isocontour of water on the ab initio water-OH minimum interaction surface. The value of the contour is selected to reproduce the volume of OH in water. We obtain for OH(aq): {Delta}{sub f}H{sup o} = -0.2 {+-} 1.4 and {Delta}{sub f}G{sup o} = 5.8 {+-} 0.4 kcal/mol that are in agreement with literature values. The results provide confidence in the pulsed PAC technique for measuring aqueous thermochemistry of radicals and open the way to obtaining thermochemistry for most radicals that can be formed by reaction of OH with aqueous substrates while advancing the field of continuum solvation theory towards ab initio-defined solute cavities.

  12. Advanced Control Strategy for Single-Phase Voltage-Source Active Rectifier with Low Harmonic Emission

    NASA Astrophysics Data System (ADS)

    Blahník, Vojtĕch; Peroutka, Zdenĕk; Talla, Jakub

    2014-03-01

    This paper introduces the advanced control of single-phase voltage-source active rectifier. This control provide direct control of trolley-wire current and active damping of low-frequency disturbances at the converter ac side. Our proposed control strategy combines PR controller with feed-forward model and low-frequency harmonic compensator based on resonant controllers. Achieved experimental results show excellent converter behavior, where converter is fed by strongly distorted supply voltage.

  13. Mishap risk control for advanced aerospace/composite materials

    NASA Technical Reports Server (NTRS)

    Olson, John M.

    1994-01-01

    Although advanced aerospace materials and advanced composites provide outstanding performance, they also present several unique post-mishap environmental, safety, and health concerns. The purpose of this paper is to provide information on some of the unique hazards and concerns associated with these materials when damaged by fire, explosion, or high-energy impact. Additionally, recommended procedures and precautions are addressed as they pertain to all phases of a composite aircraft mishap response, including fire-fighting, investigation, recovery, clean-up, and guidelines are general in nature and not application-specific. The goal of this project is to provide factual and realistic information which can be used to develop consistent and effective procedures and policies to minimize the potential environmental, safety, and health impacts of a composite aircraft mishap response effort.

  14. Application of a locally optimized control theory to pump dump laser-driven chemical reactions

    NASA Astrophysics Data System (ADS)

    Ohtsuki, Y.; Yahata, Y.; Kono, H.; Fujimura, Y.

    1998-05-01

    A locally optimized control theory is developed. This theory is applied to pump-dump laser-driven chemical reactions via an electronically excited state. The results show that the theory can design the pulse shapes for chemical reactions with high quantum yields in strong laser intensity regimes in which perturbative treatments break down.

  15. Locus of Control and Academic Achievement: Integrating Social Learning Theory and Expectancy-Value Theory

    ERIC Educational Resources Information Center

    Youse, Keith Edward

    2012-01-01

    The current study examines predictors of math achievement and college graduation by integrating social learning theory and expectancy-value theory. Data came from a nationally-representative longitudinal database tracking 12,144 students over twelve years from 8th grade forward. Models for math achievement and college graduation were tested…

  16. Advances in Thrust-Based Emergency Control of an Airplane

    NASA Technical Reports Server (NTRS)

    Creech, Gray; Burken, John J.; Burcham, Bill

    2003-01-01

    Engineers at NASA's Dryden Flight Research Center have received a patent on an emergency flight-control method implemented by a propulsion-controlled aircraft (PCA) system. Utilizing the preexisting auto-throttle and engine-pressure-ratio trim controls of the airplane, the PCA system provides pitch and roll control for landing an airplane safely without using aerodynamic control surfaces that have ceased to function because of a primary-flight-control-system failure. The installation of the PCA does not entail any changes in pre-existing engine hardware or software. [Aspects of the method and system at previous stages of development were reported in Thrust-Control System for Emergency Control of an Airplane (DRC-96-07), NASA Tech Briefs, Vol. 25, No. 3 (March 2001), page 68 and Emergency Landing Using Thrust Control and Shift of Weight (DRC-96-55), NASA Tech Briefs, Vol. 26, No. 5 (May 2002), page 58.]. Aircraft flight-control systems are designed with extensive redundancy to ensure low probabilities of failure. During recent years, however, several airplanes have exhibited major flight-control-system failures, leaving engine thrust as the last mode of flight control. In some of these emergency situations, engine thrusts were successfully modulated by the pilots to maintain flight paths or pitch angles, but in other situations, lateral control was also needed. In the majority of such control-system failures, crashes resulted and over 1,200 people died. The challenge lay in creating a means of sufficient degree of thrust-modulation control to safely fly and land a stricken airplane. A thrust-modulation control system designed for this purpose was flight-tested in a PCA an MD-11 airplane. The results of the flight test showed that without any operational control surfaces, a pilot can land a crippled airplane (U.S. Patent 5,330,131). The installation of the original PCA system entailed modifications not only of the flight-control computer (FCC) of the airplane but

  17. Advanced human-machine interface for collaborative building control

    DOEpatents

    Zheng, Xianjun S.; Song, Zhen; Chen, Yanzi; Zhang, Shaopeng; Lu, Yan

    2015-08-11

    A system for collaborative energy management and control in a building, including an energy management controller, one or more occupant HMIs that supports two-way communication between building occupants and a facility manager, and between building occupants and the energy management controller, and a facility manager HMI that supports two-way communication between the facility manager and the building occupants, and between the facility manager and the energy management controller, in which the occupant HMI allows building occupants to provide temperature preferences to the facility manager and the energy management controller, and the facility manager HMI allows the facility manager to configure an energy policy for the building as a set of rules and to view occupants' aggregated temperature preferences, and the energy management controller determines an optimum temperature range that resolves conflicting occupant temperature preferences and occupant temperature preferences that conflict with the facility manager's energy policy for the building.

  18. Adopting Industry Standards for Control Systems Within Advanced Life Support

    NASA Technical Reports Server (NTRS)

    Young, James Scott; Boulanger, Richard

    2002-01-01

    This paper gives a description of OPC (Object Linking and Embedding for Process Control) standards for process control and outlines the experiences at JSC with using these standards to interface with I/O hardware from three independent vendors. The I/O hardware was integrated with a commercially available SCADA/HMI software package to make up the control and monitoring system for the Environmental Systems Test Stand (ESTS). OPC standards were utilized for communicating with I/O hardware and the software was used for implementing monitoring, PC-based distributed control, and redundant data storage over an Ethernet physical layer using an embedded din-rail mounted PC.

  19. An introduction to stochastic control theory, path integrals and reinforcement learning

    NASA Astrophysics Data System (ADS)

    Kappen, Hilbert J.

    2007-02-01

    Control theory is a mathematical description of how to act optimally to gain future rewards. In this paper I give an introduction to deterministic and stochastic control theory and I give an overview of the possible application of control theory to the modeling of animal behavior and learning. I discuss a class of non-linear stochastic control problems that can be efficiently solved using a path integral or by MC sampling. In this control formalism the central concept of cost-to-go becomes a free energy and methods and concepts from statistical physics can be readily applied.

  20. Advanced aerodynamics and active controls. Selected NASA research

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Aerodynamic and active control concepts for application to commercial transport aircraft are discussed. Selected topics include in flight direct strike lightning research, triply redundant digital fly by wire control systems, tail configurations, winglets, and the drones for aerodynamic and structural testing (DAST) program.

  1. Advanced Study for Active Noise Control in Aircraft (ASANCA)

    NASA Technical Reports Server (NTRS)

    Borchers, Ingo U.; Emborg, Urban; Sollo, Antonio; Waterman, Elly H.; Paillard, Jacques; Larsen, Peter N.; Venet, Gerard; Goeransson, Peter; Martin, Vincent

    1992-01-01

    Aircraft interior noise and vibration measurements are included in this paper from ground and flight tests. In addition, related initial noise calculations with and without active noise control are conducted. The results obtained to date indicate that active noise control may be an effective means for reducing the critical low frequency aircraft noise.

  2. Arms Control and National Security: An Introduction. Advance Edition.

    ERIC Educational Resources Information Center

    Arms Control Association, Washington, DC.

    Suitable for use with high school students, this booklet on arms control and national security provides background information, describes basic concepts, reviews recent history, and offers suggestions for further reading. The first section, on American attitudes toward national security and arms control, defines five types of limits on weapons…

  3. Self-Control, Social Factors, and Delinquency: A Test of the General Theory of Crime among Adolescents in Hong Kong

    ERIC Educational Resources Information Center

    Cheung, Nicole W. T.; Cheung, Yuet W.

    2008-01-01

    The objectives of this study were to test the predictive power of self-control theory for delinquency in a Chinese context, and to explore if social factors as predicted in social bonding theory, differential association theory, general strain theory, and labeling theory have effects on delinquency in the presence of self-control. Self-report data…

  4. Advanced Aerodynamic Design of Passive Porosity Control Effectors

    NASA Technical Reports Server (NTRS)

    Hunter, Craig A.; Viken, Sally A.; Wood, Richard M.; Bauer, Steven X. S.

    2001-01-01

    This paper describes aerodynamic design work aimed at developing a passive porosity control effector system for a generic tailless fighter aircraft. As part of this work, a computational design tool was developed and used to layout passive porosity effector systems for longitudinal and lateral-directional control at a low-speed, high angle of attack condition. Aerodynamic analysis was conducted using the NASA Langley computational fluid dynamics code USM3D, in conjunction with a newly formulated surface boundary condition for passive porosity. Results indicate that passive porosity effectors can provide maneuver control increments that equal and exceed those of conventional aerodynamic effectors for low-speed, high-alpha flight, with control levels that are a linear function of porous area. This work demonstrates the tremendous potential of passive porosity to yield simple control effector systems that have no external moving parts and will preserve an aircraft's fixed outer mold line.

  5. Comparison of advanced distillation control methods. Third annual report

    SciTech Connect

    Riggs, J.B.

    1997-07-01

    Detailed dynamic simulations of three industrial distillation columns (a propylene/propane splitter, a xylene/toluene column, and a depropanizer) have been used to study the issue of configuration selection for diagonal PI dual composition controls, feedforward from a feed composition analyzer, and decouplers. Auto Tune Variation (ATV) identification with on-line detuning for setpoint changes was used for tuning the diagonal proportional integral (PI) composition controls. In addition, robustness tests were conducted by inducting reboiler duty upsets. For single composition control, the (L, V) configuration was found to be best. For dual composition control, the optimum configuration changes from one column to another. Moreover, the use of analysis tools, such as RGA, appears to be of little value in identifying the optimum configuration for dual composition control. Using feedforward from a feed composition analyzer and using decouplers are shown to offer significant advantages for certain specific cases.

  6. Advanced Ground Systems Maintenance Cryogenics Test Lab Control System Upgrade Project

    NASA Technical Reports Server (NTRS)

    Harp, Janice Leshay

    2014-01-01

    This project will outfit the Simulated Propellant Loading System (SPLS) at KSC's Cryogenics Test Laboratory with a new programmable logic control system. The control system upgrade enables the Advanced Ground Systems Maintenace Element Integration Team and other users of the SPLS to conduct testing in a controls environment similar to that used at the launch pad.

  7. Advanced methods for controlling untethered magnetic devices using rotating magnetic fields

    NASA Astrophysics Data System (ADS)

    Mahoney, Arthur W., Jr.

    This dissertation presents results documenting advancements on the control of untethered magnetic devices, such as magnetic "microrobots" and magnetically actuated capsule endoscopes, motivated by problems in minimally invasive medicine. This dissertation focuses on applying rotating magnetic fields for magnetic manipulation. The contributions include advancements in the way that helical microswimmers (devices that mimic the propulsion of bacterial flagella) are controlled in the presence of gravitational forces, advancements in ways that groups of untethered magnetic devices can be differentiated and semi-independently controlled, advancements in the way that untethered magnetic device can be controlled with a single rotating permanent magnet, and an improved understanding in the nature of the magnetic force applied to an untethered device by a rotating magnet.

  8. Exploring the Utility of Social Control Theory for Youth Development: Issues of Attachment, Involvement, and Gender.

    ERIC Educational Resources Information Center

    Huebner, Angela J.; Betts, Sherry C.

    2002-01-01

    Investigated the utility of social control theory's attachment and involvement bonds as protective factors to examine gender differences in reports of delinquency and academic achievement. Surveys of 7th-12th graders indicated that although several of the involvement bond variables of social control theory were predictive of both delinquency and…

  9. Affective Dynamics of Leadership: An Experimental Test of Affect Control Theory

    ERIC Educational Resources Information Center

    Schroder, Tobias; Scholl, Wolfgang

    2009-01-01

    Affect Control Theory (ACT; Heise 1979, 2007) states that people control social interactions by striving to maintain culturally shared feelings about the situation. The theory is based on mathematical models of language-based impression formation. In a laboratory experiment, we tested the predictive power of a new German-language ACT model with…

  10. Process control integration requirements for advanced life support systems applicable to manned space missions

    NASA Technical Reports Server (NTRS)

    Spurlock, Paul; Spurlock, Jack M.; Evanich, Peggy L.

    1991-01-01

    An overview of recent developments in process-control technology which might have applications in future advanced life support systems for long-duration space operations is presented. Consideration is given to design criteria related to control system selection and optimization, and process-control interfacing methodology. Attention is also given to current life support system process control strategies, innovative sensors, instrumentation and control, and innovations in process supervision.

  11. Modeling transonic aerodynamic response using nonlinear systems theory for use with modern control theory

    NASA Technical Reports Server (NTRS)

    Silva, Walter A.

    1993-01-01

    The presentation begins with a brief description of the motivation and approach that has been taken for this research. This will be followed by a description of the Volterra Theory of Nonlinear Systems and the CAP-TSD code which is an aeroelastic, transonic CFD (Computational Fluid Dynamics) code. The application of the Volterra theory to a CFD model and, more specifically, to a CAP-TSD model of a rectangular wing with a NACA 0012 airfoil section will be presented.

  12. Reduced state feedback gain computation. [optimization and control theory for aircraft control

    NASA Technical Reports Server (NTRS)

    Kaufman, H.

    1976-01-01

    Because application of conventional optimal linear regulator theory to flight controller design requires the capability of measuring and/or estimating the entire state vector, it is of interest to consider procedures for computing controls which are restricted to be linear feedback functions of a lower dimensional output vector and which take into account the presence of measurement noise and process uncertainty. Therefore, a stochastic linear model that was developed is presented which accounts for aircraft parameter and initial uncertainty, measurement noise, turbulence, pilot command and a restricted number of measurable outputs. Optimization with respect to the corresponding output feedback gains was performed for both finite and infinite time performance indices without gradient computation by using Zangwill's modification of a procedure originally proposed by Powell. Results using a seventh order process show the proposed procedures to be very effective.

  13. Advanced Electric Distribution, Switching, and Conversion Technology for Power Control

    NASA Technical Reports Server (NTRS)

    Soltis, James V.

    1998-01-01

    The Electrical Power Control Unit currently under development by Sundstrand Aerospace for use on the Fluids Combustion Facility of the International Space Station is the precursor of modular power distribution and conversion concepts for future spacecraft and aircraft applications. This unit combines modular current-limiting flexible remote power controllers and paralleled power converters into one package. Each unit includes three 1-kW, current-limiting power converter modules designed for a variable-ratio load sharing capability. The flexible remote power controllers can be used in parallel to match load requirements and can be programmed for an initial ON or OFF state on powerup. The unit contains an integral cold plate. The modularity and hybridization of the Electrical Power Control Unit sets the course for future spacecraft electrical power systems, both large and small. In such systems, the basic hybridized converter and flexible remote power controller building blocks could be configured to match power distribution and conversion capabilities to load requirements. In addition, the flexible remote power controllers could be configured in assemblies to feed multiple individual loads and could be used in parallel to meet the specific current requirements of each of those loads. Ultimately, the Electrical Power Control Unit design concept could evolve to a common switch module hybrid, or family of hybrids, for both converter and switchgear applications. By assembling hybrids of a common current rating and voltage class in parallel, researchers could readily adapt these units for multiple applications. The Electrical Power Control Unit concept has the potential to be scaled to larger and smaller ratings for both small and large spacecraft and for aircraft where high-power density, remote power controllers or power converters are required and a common replacement part is desired for multiples of a base current rating.

  14. Concurrent design of an RTP chamber and advanced control system

    SciTech Connect

    Spence, P.; Schaper, C.; Kermani, A.

    1995-12-31

    A concurrent-engineering approach is applied to the development of an axisymmetric rapid-thermal-processing (RTP) reactor and its associated temperature controller. Using a detailed finite-element thermal model as a surrogate for actual hardware, the authors have developed and tested a multi-input multi-output (MIMO) controller. Closed-loop simulations are performed by linking the control algorithm with the finite-element code. Simulations show that good temperature uniformity is maintained on the wafer during both steady and transient conditions. A numerical study shows the effect of ramp rate, feedback gain, sensor placement, and wafer-emissivity patterns on system performance.

  15. Hierarchical control of ride height system for electronically controlled air suspension based on variable structure and fuzzy control theory

    NASA Astrophysics Data System (ADS)

    Xu, Xing; Zhou, Kongkang; Zou, Nannan; Jiang, Hong; Cui, Xiaoli

    2015-09-01

    The current research of air suspension mainly focuses on the characteristics and design of the air spring. In fact, electronically controlled air suspension (ECAS) has excellent performance in flexible height adjustment during different driving conditions. However, the nonlinearity of the ride height adjusting system and the uneven distribution of payload affect the control accuracy of ride height and the body attitude. Firstly, the three-point measurement system of three height sensors is used to establish the mathematical model of the ride height adjusting system. The decentralized control of ride height and the centralized control of body attitude are presented to design the ride height control system for ECAS. The exact feedback linearization method is adopted for the nonlinear mathematical model of the ride height system. Secondly, according to the hierarchical control theory, the variable structure control (VSC) technique is used to design a controller that is able to adjust the ride height for the quarter-vehicle anywhere, and each quarter-vehicle height control system is independent. Meanwhile, the three-point height signals obtained by three height sensors are tracked to calculate the body pitch and roll attitude over time, and then by calculating the deviation of pitch and roll and its rates, the height control correction is reassigned based on the fuzzy algorithm. Finally, to verify the effectiveness and performance of the proposed combined control strategy, a validating test of ride height control system with and without road disturbance is carried out. Testing results show that the height adjusting time of both lifting and lowering is over 5 s, and the pitch angle and the roll angle of body attitude are less than 0.15°. This research proposes a hierarchical control method that can guarantee the attitude stability, as well as satisfy the ride height tracking system.

  16. ADVANCED TOKAMAK OPERATION USING THE DIII-D PLASMA CONTROL SYSTEM

    SciTech Connect

    HUMPHREYS,DA; FERRON,JR; GAROFALO,AM; HYATT,AW; JERNIGAN,TC; JOHNSON,RD; LAHAYE,RJ; LEUER,JA; OKABAYASHI,M; PENAFLOR,BG; SCOVILLE,JT; STRAIT,EJ; WALKER,ML; WHYTE,DG

    2002-10-01

    A271 ADVANCED TOKAMAK OPERATION USING THE DIII-D PLASMA CONTROL SYSTEM. The principal focus of experimental operations in the DIII-D tokamak is the advanced tokamak (AT) regime to achieve, which requires highly integrated and flexible plasma control. In a high performance advanced tokamak, accurate regulation of the plasma boundary, internal profiles, pumping, fueling, and heating must be well coordinated with MHD control action to stabilize such instabilities as tearing modes and resistive wall modes. Sophisticated monitors of the operational regime must provide detection of off-normal conditions and trigger appropriate safety responses with acceptable levels of reliability. Many of these capabilities are presently implemented in the DIII-D plasma control system (PCS), and are now in frequent or routine operational use. The present work describes recent development, implementation, and operational experience with AT regime control elements for equilibrium control, MHD suppression, and off-normal event detection and response.

  17. Recent advances in electronic structure theory and their influence on the accuracy of ab initio potential energy surfaces

    NASA Technical Reports Server (NTRS)

    Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.; Taylor, Peter R.

    1988-01-01

    Recent advances in electronic structure theory and the availability of high speed vector processors have substantially increased the accuracy of ab initio potential energy surfaces. The recently developed atomic natural orbital approach for basis set contraction has reduced both the basis set incompleteness and superposition errors in molecular calculations. Furthermore, full CI calculations can often be used to calibrate a CASSCF/MRCI approach that quantitatively accounts for the valence correlation energy. These computational advances also provide a vehicle for systematically improving the calculations and for estimating the residual error in the calculations. Calculations on selected diatomic and triatomic systems will be used to illustrate the accuracy that currently can be achieved for molecular systems. In particular, the F+H2 yields HF+H potential energy hypersurface is used to illustrate the impact of these computational advances on the calculation of potential energy surfaces.

  18. Recent advances in electronic structure theory and their influence on the accuracy of ab initio potential energy surfaces

    NASA Technical Reports Server (NTRS)

    Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.; Taylor, Peter R.

    1989-01-01

    Recent advances in electronic structure theory and the availability of high speed vector processors have substantially increased the accuracy of ab initio potential energy surfaces. The recently developed atomic natural orbital approach for basis set contraction has reduced both the basis set incompleteness and superposition errors in molecular calculations. Furthermore, full CI calculations can often be used to calibrate a CASSCF/MRCI approach that quantitatively accounts for the valence correlation energy. These computational advances also provide a vehicle for systematically improving the calculations and for estimating the residual error in the calculations. Calculations on selected diatomic and triatomic systems will be used to illustrate the accuracy that currently can be achieved for molecular systems. In particular, the F + H2 yields HF + H potential energy hypersurface is used to illustrate the impact of these computational advances on the calculation of potential energy surfaces.

  19. Recent advances in electronic structure theory and their influence on the accuracy of ab initio potential energy surfaces

    NASA Astrophysics Data System (ADS)

    Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.; Taylor, Peter R.

    Recent advances in electronic structure theory and the availability of high speed vector processors have substantially increased the accuracy of ab initio potential energy surfaces. The recently developed atomic natural orbital approach for basis set contraction has reduced both the basis set incompleteness and superposition errors in molecular calculations. Furthermore, full CI calculations can often be used to calibrate a CASSCF/MRCI approach that quantitatively accounts for the valence correlation energy. These computational advances also provide a vehicle for systematically improving the calculations and for estimating the residual error in the calculations. Calculations on selected diatomic and triatomic systems will be used to illustrate the accuracy that currently can be achieved for molecular systems. In particular, the F + H2 yields HF + H potential energy hypersurface is used to illustrate the impact of these computational advances on the calculation of potential energy surfaces.

  20. Recent advances in electronic structure theory and their influence on the accuracy of ab initio potential energy surfaces

    NASA Astrophysics Data System (ADS)

    Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.; Taylor, Peter R.

    Recent advances in electronic structure theory and the availability of high speed vector processors have substantially increased the accuracy of ab initio potential energy surfaces. The recently developed atomic natural orbital approach for basis set contraction has reduced both the basis set incompleteness and superposition errors in molecular calculations. Furthermore, full CI calculations can often be used to calibrate a CASSCF/MRCI approach that quantitatively accounts for the valence correlation energy. These computational advances also provide a vehicle for systematically improving the calculations and for estimating the residual error in the calculations. Calculations on selected diatomic and triatomic systems will be used to illustrate the accuracy that currently can be achieved for molecular systems. In particular, the F+H2 yields HF+H potential energy hypersurface is used to illustrate the impact of these computational advances on the calculation of potential energy surfaces.

  1. Advanced Guidance and Control Project for Reusable Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Hanson, John M.

    2000-01-01

    The goals of this project are to significantly reduce the time and cost associated with guidance and control design for reusable launch vehicles, and to increase their safety and reliability. Success will lead to reduced cycle times during vehicle design and to reduced costs associated with flying to new orbits, with new payloads, and with modified vehicles. Success will also lead to more robustness to unforeseen circumstances in flight thereby enhancing safety and reducing risk. There are many guidance and control methods available that hold some promise for improvement in the desired areas. Investigators are developing a representative set of independent guidance and control methods for this project. These methods are being incorporated into a high-fidelity off is being conducted across a broad range of flight requirements. The guidance and control methods that perform the best will have demonstrated the desired qualities.

  2. Advanced Instrumentation, Information, and Control Systems Technologies Technical Program Plan

    SciTech Connect

    Bruce Hallbert

    2012-09-01

    Reliable instrumentation, information, and control (II&C) systems technologies are essential to ensuring safe and efficient operation of the U.S. light water reactor (LWR) fleet. These technologies affect every aspect of nuclear power plant (NPP) and balance-of-plant operations. In 1997, the National Research Council conducted a study concerning the challenges involved in modernization of digital instrumentation and control systems in NPPs. Their findings identified the need for new II&C technology integration.

  3. Antimicrobial Materials for Advanced Microbial Control in Spacecraft Water Systems

    NASA Technical Reports Server (NTRS)

    Birmele, Michele; Caro, Janicce; Newsham, Gerard; Roberts, Michael; Morford, Megan; Wheeler, Ray

    2012-01-01

    Microbial detection, identification, and control are essential for the maintenance and preservation of spacecraft water systems. Requirements set by NASA put limitations on the energy, mass, materials, noise, cost, and crew time that can be devoted to microbial control. Efforts are being made to attain real-time detection and identification of microbial contamination in microgravity environments. Research for evaluating technologies for capability enhancement on-orbit is currently focused on the use of adenosine triphosphate (ATP) analysis for detection purposes and polymerase chain reaction (peR) for microbial identification. Additional research is being conducted on how to control for microbial contamination on a continual basis. Existing microbial control methods in spacecraft utilize iodine or ionic silver biocides, physical disinfection, and point-of-use sterilization filters. Although these methods are effective, they require re-dosing due to loss of efficacy, have low human toxicity thresholds, produce poor taste, and consume valuable mass and crew time. Thus, alternative methods for microbial control are needed. This project also explores ultraviolet light-emitting diodes (UV-LEDs), surface passivation methods for maintaining residual biocide levels, and several antimicrobial materials aimed at improving current microbial control techniques, as well as addressing other materials presently under analysis and future directions to be pursued.

  4. Advanced dc motor controller for battery-powered electric vehicles

    NASA Technical Reports Server (NTRS)

    Belsterling, C. A.

    1981-01-01

    A motor generation set is connected to run from the dc source and generate a voltage in the traction motor armature circuit that normally opposes the source voltage. The functional feasibility of the concept is demonstrated with tests on a Proof of Principle System. An analog computer simulation is developed, validated with the results of the tests, applied to predict the performance of a full scale Functional Model dc Controller. The results indicate high efficiencies over wide operating ranges and exceptional recovery of regenerated energy. The new machine integrates both motor and generator on a single two bearing shaft. The control strategy produces a controlled bidirectional plus or minus 48 volts dc output from the generator permitting full control of a 96 volt dc traction motor from a 48 volt battery, was designed to control a 20 hp traction motor. The controller weighs 63.5 kg (140 lb.) and has a peak efficiency of 90% in random driving modes and 96% during the SAE J 227a/D driving cycle.

  5. AN ADVANCED CONTROL SYSTEM FOR FINE COAL FLOTATION

    SciTech Connect

    1998-10-25

    A model-based flotation control scheme is being implemented to achieve optimal performance in the handling and treatment of fine coal. The control scheme monitors flotation performance through on-line analysis of tailings ash content. Then, based on an on-line estimate of incremental ash, the pulp level is adjusted using a model-based control algorithm to compensate for feed variations and other process disturbances. Recent developments in sensor technology are being applied for on-line determination of slurry ash content. During the tenth quarter of this project, Task 6 (Equipment Procurement and Installation) was completed through the efforts of J.A. Herbst and Associates, Virginia Tech, Pittston Coal Company, and FGR Automation. As a result of this work, a model-based control system is now in place which can predict incremental ash based on tailings ash content and general plant data, and adjust pulp level accordingly to maintain a target incremental ash. Testing of this control system is expected to be carried out during the next quarter, and the results of this testing will be reported in the Eleventh Quarterly report. In addition, calibration of the video-based ash analyzer was continued and an extensive set of calibration data were obtained showing that the plant is running remarkably well under manual control. This may be a result of increased attention being paid to froth flotation as a result of this project.

  6. Truncation of the Series Expressions in the Advanced ENZ-Theory of Diffraction Integrals

    NASA Astrophysics Data System (ADS)

    van Haver, S.; Janssen, A. J. E. M.

    2014-09-01

    . The contribution of the present paper is the formulation of truncation rules for these double series expressions, with a general rule valid for all circle polynomials at the same time, and a dedicated rule that takes into account the degree and the azimuthal order of the involved circle polynomials to significantly reduce computational cost in specific cases. The truncation rules are based on effective bounds and asymptotics (of the Debye type) for the mentioned spherical Bessel functions and Jinc functions, and show feasibility of computation of practically all diffraction integrals that one encounters in the ENZ-practice. Thus it can be said that the advanced ENZ-theory is more or less completed from the computational point of view by the achievements of the present paper.

  7. "Is there nothing more practical than a good theory?": Why innovations and advances in health behavior change will arise if interventions are used to test and refine theory.

    PubMed

    Rothman, Alexander J

    2004-07-27

    Theoretical and practical innovations are needed if we are to advance efforts to persuade and enable people to make healthy changes in their behavior. In this paper, I propose that progress in our understanding of and ability to promote health behavior change depends upon greater interdependence in the research activities undertaken by basic and applied behavioral scientists. In particular, both theorists and interventionists need to treat a theory as a dynamic entity whose form and value rests upon it being rigorously applied, tested and refined in both the laboratory and the field. To this end, greater advantage needs to be taken of the opportunities that interventions afford for theory-testing and, moreover, the data generated by these activities need to stimulate and inform efforts to revise, refine, or reject theoretical principles. PMID:15279674

  8. Application of modern control theory to the design of optimum aircraft controllers

    NASA Technical Reports Server (NTRS)

    Power, L. J.

    1973-01-01

    The synthesis procedure presented is based on the solution of the output regulator problem of linear optimal control theory for time-invariant systems. By this technique, solution of the matrix Riccati equation leads to a constant linear feedback control law for an output regulator which will maintain a plant in a particular equilibrium condition in the presence of impulse disturbances. Two simple algorithms are presented that can be used in an automatic synthesis procedure for the design of maneuverable output regulators requiring only selected state variables for feedback. The first algorithm is for the construction of optimal feedforward control laws that can be superimposed upon a Kalman output regulator and that will drive the output of a plant to a desired constant value on command. The second algorithm is for the construction of optimal Luenberger observers that can be used to obtain feedback control laws for the output regulator requiring measurement of only part of the state vector. This algorithm constructs observers which have minimum response time under the constraint that the magnitude of the gains in the observer filter be less than some arbitrary limit.

  9. Multivariable control theory applied to hierarchial attitude control for planetary spacecraft

    NASA Technical Reports Server (NTRS)

    Boland, J. S., III; Russell, D. W.

    1972-01-01

    Multivariable control theory is applied to the design of a hierarchial attitude control system for the CARD space vehicle. The system selected uses reaction control jets (RCJ) and control moment gyros (CMG). The RCJ system uses linear signal mixing and a no-fire region similar to that used on the Skylab program; the y-axis and z-axis systems which are coupled use a sum and difference feedback scheme. The CMG system uses the optimum steering law and the same feedback signals as the RCJ system. When both systems are active the design is such that the torques from each system are never in opposition. A state-space analysis was made of the CMG system to determine the general structure of the input matrices (steering law) and feedback matrices that will decouple the axes. It is shown that the optimum steering law and proportional-plus-rate feedback are special cases. A derivation of the disturbing torques on the space vehicle due to the motion of the on-board television camera is presented. A procedure for computing an upper bound on these torques (given the system parameters) is included.

  10. AN ADVANCED CONTROL SYSTEM FOR FINE COAL FLOTATION

    SciTech Connect

    G.H. Luttrell; G.T. Adel

    1999-01-11

    A model-based flotation control scheme is being implemented to achieve optimal performance in the handling and treatment of fine coal. The control scheme monitors flotation performance through on-line analysis of tailings ash content. Then, based on an on-line estimate of incremental ash, the pulp level is adjusted using a model-based control algorithm to compensate for feed variations and other process disturbances. Recent developments in sensor technology are being applied for on-line determination of slurry ash content. During the eleventh quarter of this project, Task 7 (Operation and Testing) was nearly completed through the efforts of J.A. Herbst and Associates, Virginia Tech, and Pittston Coal Company. As a result of this work, a model-based control system has now been installed which can predict incremental ash based on tailings ash content and general plant data, and adjust pulp level accordingly to maintain a target incremental ash. The system has gone through a shake-down period, training has been carried out for plant operators, and the bulk of the control logic testing has been completed with the results of these tests awaiting analysis under Task 8 (System Evaluation). The flotation model has been shown to predict incremental ash quite successfully, implying that this approach may provide the basis for a useful ''soft sensor'' for on-line incremental ash analysis.

  11. Cognitive Flexibility Theory: Advanced Knowledge Acquisition in Ill-Structured Domains. Technical Report No. 441.

    ERIC Educational Resources Information Center

    Spiro, Rand J.; And Others

    Advanced knowledge acquisition in a subject area is different in many important ways from introductory learning (and from expertise). In this paper some of the special characteristics of advanced learning of complex conceptual material are discussed. The paper notes that these characteristics are often at odds with the goals and tactics of…

  12. Advanced, Integrated Control for Building Operations to Achieve 40% Energy Saving

    SciTech Connect

    Lu, Yan; Song, Zhen; Loftness, Vivian; Ji, Kun; Zheng, Sam; Lasternas, Bertrand; Marion, Flore; Yuebin, Yu

    2012-10-15

    We developed and demonstrated a software based integrated advanced building control platform called Smart Energy Box (SEB), which can coordinate building subsystem controls, integrate variety of energy optimization algorithms and provide proactive and collaborative energy management and control for building operations using weather and occupancy information. The integrated control system is a low cost solution and also features: Scalable component based architecture allows to build a solution for different building control system configurations with needed components; Open Architecture with a central data repository for data exchange among runtime components; Extendible to accommodate variety of communication protocols. Optimal building control for central loads, distributed loads and onsite energy resource; uses web server as a loosely coupled way to engage both building operators and building occupants in collaboration for energy conservation. Based on the open platform of SEB, we have investigated and evaluated a variety of operation and energy saving control strategies on Carnegie Mellon University Intelligent Work place which is equipped with alternative cooling/heating/ventilation/lighting methods, including radiant mullions, radiant cooling/heating ceiling panels, cool waves, dedicated ventilation unit, motorized window and blinds, and external louvers. Based on the validation results of these control strategies, they were integrated in SEB in a collaborative and dynamic way. This advanced control system was programmed and computer tested with a model of the Intelligent Workplace's northern section (IWn). The advanced control program was then installed in the IWn control system; the performance was measured and compared with that of the state of the art control system to verify the overall energy savings great than 40%. In addition advanced human machine interfaces (HMI's) were developed to communicate both with building occupants and

  13. Object impedance control for cooperative manipulation - Theory and experimental results

    NASA Technical Reports Server (NTRS)

    Schneider, Stanley A.; Cannon, Robert H., Jr.

    1989-01-01

    The dynamic control module being developed in the Dynamic and Strategic Control of Cooperative Manipulators (DASCCOM) project at the Stanford University Aerospace Robotics Laboratory is described. First, the cooperative manipulation problem is analyzed from a systems perspective, and the desirable features of a control system for cooperative manipulation are discussed. Next, a control policy is developed that enforces a controlled impedance not of the individual arm endpoints, but of the manipulated object itself. A parallel implementation for a multiprocessor system is presented. The controller fully compensates for the system dynamics and directly controls the object internal forces. Most importantly, it presents a simple, powerful, intuitive interface to the strategic controller. Experimental results for a dual two-link arm robotic system are presented to verify the controllers performance, for both free-motion slews and environmental contact.

  14. Object impedance control for cooperative manipulation - Theory and experimental results

    NASA Technical Reports Server (NTRS)

    Schneider, Stanley A.; Cannon, Robert H., Jr.

    1992-01-01

    This paper presents the dynamic control module of the Dynamic and Strategic Control of Cooperating Manipulators (DASCCOM) project at Stanford University's Aerospace Robotics Laboratory. First, the cooperative manipulation problem is analyzed from a systems perspective, and the desirable features of a control system for cooperative manipulation are discussed. Next, a control policy is developed that enforces a controlled impedance not of the individual arm endpoints, but of the manipulated object itself. A parallel implementation for a multiprocessor system is presented. The controller fully compensates for the system dynamics and directly controls the object internal forces. Most importantly, it presents a simple, powerful, intuitive interface to higher level strategic control modules. Experimental results from a dual two-link-arm robotic system are used to compare the object impedance controller with other strategies, both for free-motion slews and environmental contact.

  15. Decentralized adaptive control of manipulators - Theory, simulation, and experimentation

    NASA Technical Reports Server (NTRS)

    Seraji, Homayoun

    1989-01-01

    The author presents a simple decentralized adaptive-control scheme for multijoint robot manipulators based on the independent joint control concept. The control objective is to achieve accurate tracking of desired joint trajectories. The proposed control scheme does not use the complex manipulator dynamic model, and each joint is controlled simply by a PID (proportional-integral-derivative) feedback controller and a position-velocity-acceleration feedforward controller, both with adjustable gains. Simulation results are given for a two-link direct-drive manipulator under adaptive independent joint control. The results illustrate trajectory tracking under coupled dynamics and varying payload. The proposed scheme is implemented on a MicroVAX II computer for motion control of the three major joints of a PUMA 560 arm. Experimental results are presented to demonstrate that trajectory tracking is achieved despite coupled nonlinear joint dynamics.

  16. An Integrated Theory for Predicting the Hydrothermomechanical Response of Advanced Composite Structural Components

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.; Lark, R. F.; Sinclair, J. H.

    1977-01-01

    An integrated theory is developed for predicting the hydrothermomechanical (HDTM) response of fiber composite components. The integrated theory is based on a combined theoretical and experimental investigation. In addition to predicting the HDTM response of components, the theory is structured to assess the combined hydrothermal effects on the mechanical properties of unidirectional composites loaded along the material axis and off-axis, and those of angleplied laminates. The theory developed predicts values which are in good agreement with measured data at the micromechanics, macromechanics, laminate analysis and structural analysis levels.

  17. ADVANCES TOWARDS THE MEASUREMENT AND CONTROL LHC TUNE AND CHROMATICITY

    SciTech Connect

    CAMERON, P.; CUPOLO, J.; DEGEN, C.; DELLAPENNA, A.; HOFF, L.; MEAD, J.; SIKORA, R.

    2005-06-06

    Requirements for tune and chromaticity control in most superconducting hadron machines, and in particular the LHC, are stringent. In order to reach nominal operation, the LHC will almost certainly require feedback on both tune and chromaticity. Experience at RHIC has also shown that coupling control is crucial to successful tune feedback. A prototype baseband phase-locked loop (PLL) tune measurement system has recently been brought into operation at RHIC as part of the US LHC Accelerator Research Program (LARP). We report on the performance of that system and compare it with the extensive accumulation of data from the RHIC 245MHz PLL.

  18. Control system design for spacecraft formation flying: Theory and experiment

    NASA Astrophysics Data System (ADS)

    Robertson, Andrew Dunbar

    Spacecraft formation flying is an enabling technology for many future space science missions, such as separated spacecraft interferometers (SSI). However the sensing, control and coordination of such instruments pose many new design challenges. SSI missions will require precise relative sensing and control, fuel-efficient, fuel-balanced operation to maximize mission life and group-level autonomy to reduce operations costs. Enabling these new formation flying capabilities requires precise relative sensing and estimation, enhanced control capabilities such as cooperative control (multiple independent spacecraft acting together), group-level formation management and informed design of a system architecture to manage distributed sensing and control-system resources. This research defines an end-to-end control system, including the key elements unique to the formation flying problem: cooperative control, relative sensing, coordination, and the control-system architecture. A new control-system design optimizes performance under typical spacecraft constraints (e.g., on-off actuators, finite fuel, limited computation power, limited contact with ground control, etc.). Standard control techniques have been extended, and new ones synthesized to meet these goals. In designing this control system, several contributions have been made to the field of spacecraft formation flying control including: an analytic two-vehicle fuel-time-optimal cooperative control algorithm, a fast numeric multi-vehicle, optimal cooperative control algorithm that can be used as a feedforward or a feedback controller, a fleet-level coordinator for autonomous fuel balancing, validation of GPS-based relative sensing for formation flying, and trade studies of the relative control and relative-estimation-architecture design problems. These research contributions are mapped to possible applications for three spacecraft formation flying missions currently in development. The lessons learned from this research

  19. Load Theory of Selective Attention and Cognitive Control

    ERIC Educational Resources Information Center

    Lavie, Nilli; Hirst, Aleksandra; de Fockert, Jan W.; Viding, Essi

    2004-01-01

    A load theory of attention in which distractor rejection depends on the level and type of load involved in current processing was tested. A series of experiments demonstrates that whereas high perceptual load reduces distractor interference, working memory load or dual-task coordination load increases distractor interference. These findings…

  20. Process Dynamics and Control, a Theory-Experiential Approach.

    ERIC Educational Resources Information Center

    Perna, A. J.; And Others

    A required senior-level chemical engineering course at Colorado State University is described. The first nine weeks are devoted to the theory portion of the course, which includes the following topics: LaPlace transformations and time constants, block diagrams, inverse transformations, linearization, frequency response analysis, graphical…

  1. Avian Coccidiosis: recent advancements in control measures and vaccine development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Coccidiosis is recognized as the major parasitic disease of poultry and is caused by the apicomplexan protozoa Eimeria. Coccidiosis seriously impairs the growth and feed utilization of infected animals resulting in loss of productivity. Conventional disease control strategies rely heavily on chemo...

  2. ADVANCED SORBENTS FOR CONTROL OF MULTIPLE AIR POLLUTANTS

    EPA Science Inventory

    EPA's Clean Air Interstate Rule (CAIR)and Utility MACT rulemaking are focusing on future reductions of NOX, SO2, and mercury emissions from power plants. Multipollutant sorbents could provide a cost-effective approach to control these emissions. This research will develop, charac...

  3. Status of dual control theory. [stochastic decision making

    NASA Technical Reports Server (NTRS)

    Tse, E.

    1975-01-01

    Theoretical studies of decision making and stochastic processes are discussed. Several approaches are described for an improved performing control method. It is shown that control performance is highly dependent on the knowledge of the unknown parameters in the system.

  4. An Advanced Control System For Fine Coal Flotation

    SciTech Connect

    G. H. Luttrell; G. T. Adel

    1998-08-25

    A model-based flotation control scheme is being implemented to achieve optimal performance in the handling and treatment of fine coal. The control scheme monitors flotation performance through on-line analysis of ash content. Then, based on the economic and metallurgical performance of the circuit, variables such as collector dosage, frother dosage, and pulp level are adjusted using model-based control algorithms to compensate for feed variations and other process disturbances. Recent developments in sensor technology are being applied for on-line determination of slurry ash content. During the ninth quarter of this project, Task 3 (Model Building and Computer Simulation) and Task 4 (Sensor Testing) were nearly completed, and Task 6 (Equipment Procurement and Installation) was initiated. Previously, data collected from the plant sampling campaign (Task 2) were used to construct a population balance model to describe the steady-state and dynamic behavior of the flotation circuit. The details of this model were presented in the Eighth Quarterly Technical Progress Report. During the past quarter, a flotation circuit simulator was designed and used to evaluate control strategies. As a result of this work, a model-based control strategy has been conceived which will allow manipulated variables to be adjusted in response to disturbances to achieve a target incremental ash value in the last cell of the bank. This will, in effect, maximize yield at an acceptable product quality. During this same period, a video-based ash analyzer was installed on the flotation tailings stream at the Moss No. 3 preparation plant. A preliminary calibration curve was established, and data are continuing to be collected in order to improve the calibration of the analyzer.

  5. Theoretically Motivated Interventions for Reducing Sexual Risk Taking in Adolescence: A Randomized Controlled Experiment Applying Fuzzy-trace Theory

    PubMed Central

    Reyna, Valerie F.; Mills, Britain A.

    2014-01-01

    Fuzzy-trace theory is a theory of memory, judgment, and decision-making, and their development. We applied advances in this theory to increase the efficacy and durability of a multicomponent intervention to promote risk reduction and avoidance of premature pregnancy and STIs. 734 adolescents from high schools and youth programs in three states (Arizona, Texas, and New York) were randomly assigned to one of three curriculum groups: RTR (Reducing the Risk), RTR+ (a modified version of RTR using fuzzy-trace theory), and a control group. We report effects of curriculum on self-reported behaviors and behavioral intentions plus psychosocial mediators of those effects, namely, attitudes and norms, motives to have sex or get pregnant, self-efficacy and behavioral control, and gist/verbatim constructs. Among 26 outcomes, 19 showed an effect of at least one curriculum relative to the control group: RTR+ produced improvements for 17 outcomes and RTR produced improvements for 12 outcomes. For RTR+, two differences (for perceived parental norms and global benefit perception) were confined to age, gender, or racial/ethnic subgroups. Effects of RTR+ on sexual initiation emerged six months after the intervention, when many adolescents became sexually active. Effects of RTR+ were greater than RTR for nine outcomes, and remained significantly greater than controls at one-year follow-up for 12 outcomes. Consistent with fuzzy-trace theory, results suggest that, by emphasizing gist representations, which are preserved over long time periods and are key memories used in decision-making, the enhanced intervention produced larger and more sustained effects on behavioral outcomes and psychosocial mediators of adolescent risk-taking. PMID:24773191

  6. Theoretically motivated interventions for reducing sexual risk taking in adolescence: a randomized controlled experiment applying fuzzy-trace theory.

    PubMed

    Reyna, Valerie F; Mills, Britain A

    2014-08-01

    Fuzzy-trace theory is a theory of memory, judgment, and decision making, and their development. We applied advances in this theory to increase the efficacy and durability of a multicomponent intervention to promote risk reduction and avoidance of premature pregnancy and sexually transmitted infections. Seven hundred and thirty-four adolescents from high schools and youth programs in 3 states (Arizona, Texas, and New York) were randomly assigned to 1 of 3 curriculum groups: RTR (Reducing the Risk), RTR+ (a modified version of RTR using fuzzy-trace theory), and a control group. We report effects of curriculum on self-reported behaviors and behavioral intentions plus psychosocial mediators of those effects: namely, attitudes and norms, motives to have sex or get pregnant, self-efficacy and behavioral control, and gist/verbatim constructs. Among 26 outcomes, 19 showed an effect of at least 1 curriculum relative to the control group: RTR+ produced improvements for 17 outcomes and RTR produced improvements for 12 outcomes. For RTR+, 2 differences (for perceived parental norms and global benefit perception) were confined to age, gender, or racial/ethnic subgroups. Effects of RTR+ on sexual initiation emerged 6 months after the intervention, when many adolescents became sexually active. Effects of RTR+ were greater than RTR for 9 outcomes, and remained significantly greater than controls at 1-year follow-up for 12 outcomes. Consistent with fuzzy-trace theory, results suggest that by emphasizing gist representations, which are preserved over long periods and are key memories used in decision making, the enhanced intervention produced larger and more sustained effects on behavioral outcomes and psychosocial mediators of adolescent risk taking. PMID:24773191

  7. Optical control of the Advanced Technology Solar Telescope.

    PubMed

    Upton, Robert

    2006-08-10

    The Advanced Technology Solar Telescope (ATST) is an off-axis Gregorian astronomical telescope design. The ATST is expected to be subject to thermal and gravitational effects that result in misalignments of its mirrors and warping of its primary mirror. These effects require active, closed-loop correction to maintain its as-designed diffraction-limited optical performance. The simulation and modeling of the ATST with a closed-loop correction strategy are presented. The correction strategy is derived from the linear mathematical properties of two Jacobian, or influence, matrices that map the ATST rigid-body (RB) misalignments and primary mirror figure errors to wavefront sensor (WFS) measurements. The two Jacobian matrices also quantify the sensitivities of the ATST to RB and primary mirror figure perturbations. The modeled active correction strategy results in a decrease of the rms wavefront error averaged over the field of view (FOV) from 500 to 19 nm, subject to 10 nm rms WFS noise. This result is obtained utilizing nine WFSs distributed in the FOV with a 300 nm rms astigmatism figure error on the primary mirror. Correction of the ATST RB perturbations is demonstrated for an optimum subset of three WFSs with corrections improving the ATST rms wavefront error from 340 to 17.8 nm. In addition to the active correction of the ATST, an analytically robust sensitivity analysis that can be generally extended to a wider class of optical systems is presented. PMID:16926876

  8. Control of an ozone generator - theory and practice

    NASA Astrophysics Data System (ADS)

    Chalmers, I. D.; Baird, R. C.; Kelly, T.

    1998-06-01

    The process of ozone generating using `silent' or `barrier' discharges is described and analysed. Based upon conclusions from the analysis, a voltage control circuit is described which utilizes two IGBTs as switching devices with associated control circuitry. The circuit so developed has been used to control the output from a 0957-0233/9/6/016/img6 commercial ozone generator.

  9. Objectification Theory and Psychology of Women: A Decade of Advances and Future Directions

    ERIC Educational Resources Information Center

    Moradi, Bonnie; Huang, Yu-Ping

    2008-01-01

    Fredrickson and Roberts (1997) proposed objectification theory as an integrative framework for understanding how women's socialization and experiences of sexual objectification are translated into mental health problems. This article reviews the past decade of research grounded in objectification theory and highlights needed directions for future…

  10. Recent advances with generalized entropy theory of glass-formation in polymers

    NASA Astrophysics Data System (ADS)

    Freed, Karl

    The generalized entropy theory (GET) of glass-formation in polymers is a combination of the lattice cluster theory (LCT) for the configurational entropy density with the Adam-Gibbs (AG) theory for the structural relaxation time. A greatly simplified form of the GET (whose expression for the free energy is roughly double that of Flory-Huggins theory) accurately reproduces the four characteristic temperatures of glass-formation (the onset, crossover, glass transition, and Kauzmann temperatures) of the full GET to within 4K for a series of models of polymers composed of semi-flexible chains having the structure of poly(n-alpha olefins). The theory is now simple enough to be used in courses in polymer physics. Although the successes of the GET provide a strong validation of the final form of the AG theory provided the configurational entropy is used, the physical basis of the AG theory has remained an enigma. Hence, we have developed a new, more general, statistical mechanical derivation of AG theory that explains the previously perplexing observations that the string-like elementary excitations have the mass and temperature dependence of systems undergoing equilibrium self-assembly. This work is supported by the (U.S.) Department of Energy (DOE), Office of Basic Energy Sciences, Division of Materials Sciences and Engineering under Award No. DE- SC0008631.

  11. Advancing Educational Theory by Enhancing Practice in a Technology-Supported Genetics Learning Environment.

    ERIC Educational Resources Information Center

    Hickey, Daniel T.; Kindfield, Ann C. H.; Horwitz, Paul; Christie, Mary Ann

    1999-01-01

    Highlights key points from national reports addressing contemporary perspectives on learning theory, K-12 educational technology, educational theory development, and educational research policy, using illustrations from GenScope, an open-ended exploratory software tool that lets students investigate various phenomena in genetics. Illustrations…

  12. How Analogue Research Can Advance Descriptive Evaluation Theory: Understanding (and Improving) Stakeholder Dialogue

    ERIC Educational Resources Information Center

    Campbell, Bernadette; Mark, Melvin M.

    2015-01-01

    Evaluation theories can be tested in various ways. One approach, the experimental analogue study, is described and illustrated in this article. The approach is presented as a method worthy to use in the pursuit of what Alkin and others have called descriptive evaluation theory. Drawing on analogue studies conducted by the first author, we…

  13. Online Asynchronous Threaded Discussions: Good Enough to Advance Students through the Proximal Zone of Activity Theory?

    ERIC Educational Resources Information Center

    Maurino, Paula San Millan

    2007-01-01

    This paper presents a study which involved researching student interaction and participation under the lens of Activity Theory and Social Computing. Activity Theory is a philosophical framework that integrates the objective, the sociocultural, and the ecological, while Social Computing describes any type of computing application in which software…

  14. Advanced transport operating system software upgrade: Flight management/flight controls software description

    NASA Technical Reports Server (NTRS)

    Clinedinst, Winston C.; Debure, Kelly R.; Dickson, Richard W.; Heaphy, William J.; Parks, Mark A.; Slominski, Christopher J.; Wolverton, David A.

    1988-01-01

    The Flight Management/Flight Controls (FM/FC) software for the Norden 2 (PDP-11/70M) computer installed on the NASA 737 aircraft is described. The software computes the navigation position estimates, guidance commands, those commands to be issued to the control surfaces to direct the aircraft in flight based on the modes selected on the Advanced Guidance Control System (AGSC) mode panel, and the flight path selected via the Navigation Control/Display Unit (NCDU).

  15. Advanced Control and Protection system Design Methods for Modular HTGRs

    SciTech Connect

    Ball, Sydney J; Wilson Jr, Thomas L; Wood, Richard Thomas

    2012-06-01

    The project supported the Nuclear Regulatory Commission (NRC) in identifying and evaluating the regulatory implications concerning the control and protection systems proposed for use in the Department of Energy's (DOE) Next-Generation Nuclear Plant (NGNP). The NGNP, using modular high-temperature gas-cooled reactor (HTGR) technology, is to provide commercial industries with electricity and high-temperature process heat for industrial processes such as hydrogen production. Process heat temperatures range from 700 to 950 C, and for the upper range of these operation temperatures, the modular HTGR is sometimes referred to as the Very High Temperature Reactor or VHTR. Initial NGNP designs are for operation in the lower temperature range. The defining safety characteristic of the modular HTGR is that its primary defense against serious accidents is to be achieved through its inherent properties of the fuel and core. Because of its strong negative temperature coefficient of reactivity and the capability of the fuel to withstand high temperatures, fast-acting active safety systems or prompt operator actions should not be required to prevent significant fuel failure and fission product release. The plant is designed such that its inherent features should provide adequate protection despite operational errors or equipment failure. Figure 1 shows an example modular HTGR layout (prismatic core version), where its inlet coolant enters the reactor vessel at the bottom, traversing up the sides to the top plenum, down-flow through an annular core, and exiting from the lower plenum (hot duct). This research provided NRC staff with (a) insights and knowledge about the control and protection systems for the NGNP and VHTR, (b) information on the technologies/approaches under consideration for use in the reactor and process heat applications, (c) guidelines for the design of highly integrated control rooms, (d) consideration for modeling of control and protection system designs for

  16. Towards energy efficient operation of Heating, Ventilation and Air Conditioning systems via advanced supervisory control design

    NASA Astrophysics Data System (ADS)

    Oswiecinska, A.; Hibbs, J.; Zajic, I.; Burnham, K. J.

    2015-11-01

    This paper presents conceptual control solution for reliable and energy efficient operation of heating, ventilation and air conditioning (HVAC) systems used in large volume building applications, e.g. warehouse facilities or exhibition centres. Advanced two-level scalable control solution, designed to extend capabilities of the existing low-level control strategies via remote internet connection, is presented. The high-level, supervisory controller is based on Model Predictive Control (MPC) architecture, which is the state-of-the-art for indoor climate control systems. The innovative approach benefits from using passive heating and cooling control strategies for reducing the HVAC system operational costs, while ensuring that required environmental conditions are met.

  17. Advanced control concepts. [trim solution for space shuttle

    NASA Technical Reports Server (NTRS)

    Hutton, M. F.; Friedland, B.

    1973-01-01

    The selection of a trim solution that provides the space shuttle with the highest level of performance and dynamic control in the presense of wind disturbances and bias torques due to misalignment of rocket engines is described. It was determined that engine gimballing is insufficient to provide control to trim the vehicle for headwind and sidewind disturbances, and that it is necessary to use aerodynamic surfaces in conjunction with engine gimballing to achieve trim. The algebraic equations for computing the trim solution were derived from the differential equations describing the motion of the vehicle by substituting the desired trim conditions. The general problem of showing how the trim equations are derived from the equations of motion and the mathematical forms of the performance criterion is discussed in detail, along with the general equations for studying the dynamic response of the trim solution.

  18. An Advanced Control System for Fine Coal Floatation

    SciTech Connect

    G. H. Luttrell; G. T. Adel

    1998-06-01

    A model-based flotation control scheme is being implemented to achieve optimal performance in the handling and treatment of fine coal. The control scheme monitors flotation performance through on-line analysis of ash content. Then, based on the economic and metallurgical performance of the circuit, variables such as collector dosage, frother dosage, and pulp level are adjusted using model-based control algorithms to compensate for feed variations and other process disturbances. Recent developments in sensor technology are being applied for on-line determination of slurry ash content. During the eighth quarter of this project, the analysis of data collected during Task 2 (Sampling and Data Analysis) was completed, and significant progress was made on Task 3 (Model Building and Computer Simulation). Previously, a plant sampling campaign had been conducted at Pittston�s Moss No. 3 preparation plant to provide data for the development of a mathematical process model and a model-based control system. During this campaign, a one-half factorial design experiment, blocked into low and high feed rates, was conducted to investigate the effects of collector, frother, and pulp level on model parameters. In addition, samples were collected during the transient period following each change in the manipulated variables to provide data for confirmation of the dynamic process simulator. A residence time distribution (RTD) test was also conducted to estimate the mean residence time. This is a critical piece of information since no feed flowrate measurement is available, and the mean residence time can be used to estimate the feed flowrate. Feed samples were taken at timed intervals and floated in a laboratory flotation cell to investigate the magnitude of feed property disturbances and their duration.

  19. Advancing Robotic Control for Space Exploration Using Robonaut 2

    NASA Technical Reports Server (NTRS)

    Badger, Julia; Diftler, Myron; Hart, Stephen; Joyce, Charles

    2012-01-01

    Robonaut 2, or R2, arrived on the International Space Station (ISS) in February 2011 and is currently being tested in preparation for its role initially as an Intra-Vehicular Activity (IVA) tool and eventually as a robot that performs Extra-Vehicular Activities (EVA). Robonaut 2, is a state of the art dexterous anthropomorphic robotic torso designed for assisting astronauts. R2 features increased force sensing, greater range of motion, higher bandwidth, and improved dexterity over its predecessor. Robonaut 2 is unique in its ability to safely allow humans in its workspace and to perform significant tasks in a workspace designed for humans. The current operational paradigm involves either the crew or the ground control team running semi-autonomous scripts on the robot as both the astronaut and the ground team monitor R2 and the data it produces. While this is appropriate for the check-out phase of operations, the future plans for R2 will stress the current operational framework. The approach described here will outline a suite of operational modes that will be developed for Robonaut 2. These operational modes include teleoperation, shared control, directed autonomy, and supervised autonomy, and they cover a spectrum of human involvement in controlling R2.

  20. Advanced Controls for Residential Whole-House Ventilation Systems

    SciTech Connect

    Turner, William; Walker, Iain; Sherman, Max

    2014-08-01

    Whole-house ventilation systems are becoming commonplace in new construction, remodeling/renovation, and weatherization projects, driven by combinations of specific requirements for indoor air quality (IAQ), health and compliance with standards, such as ASHRAE 62.2. Ventilation systems incur an energy penalty on the home via fan power used to drive the airflow, and the additional space-conditioning load associated with heating or cooling the ventilation air. Finding a balance between IAQ and energy use is important if homes are to be adequately ventilated while not increasing the energy burden. This study used computer simulations to examine RIVEC the Residential Integrated Ventilation Controller - a prototype ventilation controller that aims to deliver whole-house ventilation rates that comply with ventilation standards, for the minimum use of energy. Four different whole-house ventilation systems were simulated, both with and without RIVEC, so that the energy and IAQ results could be compared. Simulations were conducted for 13 US climate zones, three house designs, and three envelope leakage values. The results showed that the RIVEC controller could typically return ventilation energy savings greater than 40percent without compromising long-term chronic or short-term acute exposures to relevant indoor contaminants. Critical and average peak power loads were also reduced as a consequence of using RIVEC.