First conference on ground control problems in the Illinois Coal Basin: proceedings
Energy Technology Data Exchange (ETDEWEB)
Chugh, Y. P.; Van Besien, A. [eds.
1980-06-01
The first conference on ground control problems in the Illinois Coal Basin was held at the Southern Illinois University at Carbondale, Illinois, August 22-24, 1979. Twenty-one papers from the proceedings have been entered individually into EDB; one had been entered previously from other sources. (LTN)
Ground control problems and roadheader drivage at Ombilin Coal Mine, Indonesia
Energy Technology Data Exchange (ETDEWEB)
Matsui, K.; Shimada, H.; Furukawa, H. (and others) [Kyushu University, Fukuoka (Japan). Dept. of Earth Resources and Mining Engineering
2003-09-01
In 1998, an agreement on the 'Slope Project at Ombilin III' was made between JCOAl (Japan Coal Energy Center) and PTBA. In this project, a development system of an incline was introduced to open a new underground coal mine, or Ombilin III that will begin mining operations in the 2000s to meet the necessary demand for increasing the production of Indonesian domestic coal. This paper discusses the ground control problems and the development performance of two main inclinea at Ombilin Coal Mine. 11 refs., 4 figs.
Holzhausen, K. P.; Gaertner, K. P.
1985-01-01
A significant problem concerning the integration of display and switching functions is related to the fact that numerous informative data which have to be processed by man must be read from only a few display devices. A satisfactory ergonomic design of integrated display devices and keyboards is in many cases difficult, because not all functions which can be displayed and selected are simultaneously available. A technical solution which provides an integration of display and functional elements on the basis of the highest flexibility is obtained by using a cathode ray tube with a touch-sensitive screen. The employment of an integrated data input/output system is demonstrated for the cases of onboard and ground-based flight control. Ergonomic studies conducted to investigate the suitability of an employment of touch-sensitive screens are also discussed.
Ground Control System Description Document
Energy Technology Data Exchange (ETDEWEB)
Eric Loros
2001-07-31
The Ground Control System contributes to the safe construction and operation of the subsurface facility, including accesses and waste emplacement drifts, by maintaining the configuration and stability of the openings during construction, development, emplacement, and caretaker modes for the duration of preclosure repository life. The Ground Control System consists of ground support structures installed within the subsurface excavated openings, any reinforcement made to the rock surrounding the opening, and inverts if designed as an integral part of the system. The Ground Control System maintains stability for the range of geologic conditions expected at the repository and for all expected loading conditions, including in situ rock, construction, operation, thermal, and seismic loads. The system maintains the size and geometry of operating envelopes for all openings, including alcoves, accesses, and emplacement drifts. The system provides for the installation and operation of sensors and equipment for any required inspection and monitoring. In addition, the Ground Control System provides protection against rockfall for all subsurface personnel, equipment, and the engineered barrier system, including the waste package during the preclosure period. The Ground Control System uses materials that are sufficiently maintainable and that retain the necessary engineering properties for the anticipated conditions of the preclosure service life. These materials are also compatible with postclosure waste isolation performance requirements of the repository. The Ground Control System interfaces with the Subsurface Facility System for operating envelopes, drift orientation, and excavated opening dimensions, Emplacement Drift System for material compatibility, Monitored Geologic Repository Operations Monitoring and Control System for ground control instrument readings, Waste Emplacement/Retrieval System to support waste emplacement operations, and the Subsurface Excavation System
Optimal obstacle control problem
Institute of Scientific and Technical Information of China (English)
ZHU Li; LI Xiu-hua; GUO Xing-ming
2008-01-01
In the paper we discuss some properties of the state operators of the optimal obstacle control problem for elliptic variational inequality. Existence, uniqueness and regularity of the optimal control problem are established. In addition, the approximation of the optimal obstacle problem is also studied.
Common ground, complex problems and decision making
Beers, P.J.; Boshuizen, H.P.A.; Kirschner, P.A.; Gijselaers, W.H.
2006-01-01
Organisations increasingly have to deal with complex problems. They often use multidisciplinary teams to cope with such problems where different team members have different perspectives on the problem, different individual knowledge and skills, and different approaches on how to solve the problem. I
Equivalence of the Symbol Grounding and Quantum System Identification Problems
Directory of Open Access Journals (Sweden)
Chris Fields
2014-02-01
Full Text Available The symbol grounding problem is the problem of specifying a semantics for the representations employed by a physical symbol system in a way that is neither circular nor regressive. The quantum system identification problem is the problem of relating observational outcomes to specific collections of physical degrees of freedom, i.e., to specific Hilbert spaces. It is shown that with reasonable physical assumptions these problems are equivalent. As the quantum system identification problem is demonstrably unsolvable by finite means, the symbol grounding problem is similarly unsolvable.
Minimal Controllability Problems
Olshevsky, Alex
2013-01-01
Given a linear system, we consider the problem of finding a small set of variables to affect with an input so that the resulting system is controllable. We show that this problem is NP-hard; indeed, we show that even approximating the minimum number of variables that need to be affected within a multiplicative factor of $c \\log n$ is NP-hard for some positive $c$. On the positive side, we show it is possible to find sets of variables matching this inapproximability barrier in polynomial time....
Solving Quantum Ground-State Problems with Nuclear Magnetic Resonance
Li, Zhaokai; Chen, Hongwei; Lu, Dawei; Whitfield, James D; Peng, Xinhua; Aspuru-Guzik, Alán; Du, Jiangfeng
2011-01-01
Quantum ground-state problems are computationally hard problems; for general many-body Hamiltonians, there is no classical or quantum algorithm known to be able to solve them efficiently. Nevertheless, if a trial wavefunction approximating the ground state is available, as often happens for many problems in physics and chemistry, a quantum computer could employ this trial wavefunction to project the ground state by means of the phase estimation algorithm (PEA). We performed an experimental realization of this idea by implementing a variational-wavefunction approach to solve the ground-state problem of the Heisenberg spin model with an NMR quantum simulator. Our iterative phase estimation procedure yields a high accuracy for the eigenenergies (to the 10^-5 decimal digit). The ground-state fidelity was distilled to be more than 80%, and the singlet-to-triplet switching near the critical field is reliably captured. This result shows that quantum simulators can better leverage classical trial wavefunctions than c...
Guidance and control for unmanned ground vehicles
Bateman, Peter J.
1994-06-01
Techniques for the guidance, control, and navigation of unmanned ground vehicles are described in terms of the communication bandwidth requirements for driving and control of a vehicle remote from the human operator. Modes of operation are conveniently classified as conventional teleoperation, supervisory control, and fully autonomous control. The fundamental problem of maintaining a robust non-line-of-sight communications link between the human controller and the remote vehicle is discussed, as this provides the impetus for greater autonomy in the control system and the greatest scope for innovation. While supervisory control still requires the man to be providing the primary navigational intelligence, fully autonomous operation requires that mission navigation is provided solely by on-board machine intelligence. Methods directed at achieving this performance are described using various active and passive sensing of the terrain for route navigation and obstacle detection. Emphasis is given to TV imagery and signal processing techniques for image understanding. Reference is made to the limitations of current microprocessor technology and suitable computer architectures. Some of the more recent control techniques involve the use of neural networks, fuzzy logic, and data fusion and these are discussed in the context of road following and cross country navigation. Examples of autonomous vehicle testbeds operated at various laboratories around the world are given.
Directory of Open Access Journals (Sweden)
William Margulies
2004-11-01
Full Text Available In this paper, we study a specific stochastic differential equation depending on a parameter and obtain a representation of its probability density function in terms of Jacobi Functions. The equation arose in a control problem with a quadratic performance criteria. The quadratic performance is used to eliminate the control in the standard Hamilton-Jacobi variational technique. The resulting stochastic differential equation has a noise amplitude which complicates the solution. We then solve Kolmogorov's partial differential equation for the probability density function by using Jacobi Functions. A particular value of the parameter makes the solution a Martingale and in this case we prove that the solution goes to zero almost surely as time tends to infinity.
2016-12-01
effective and practical solution that the community embraced. E. THE MIDDLE GROUND Because of the current political environment , more outside the...was made to expire once the NICS was up and running.52 James Brady passed away in 2014 due to complications from the brain damage he suffered as a...readily available means. For example, poisoning is the most common method of suicide in China because pesticides and herbicides that can be deadly are
Enhanced Ground Control for ISS Robotics Project
National Aeronautics and Space Administration — This project will investigate and adapt aides which will increase the efficiency of ISS robotics ground control operations with the intent of creating more...
Stewart, Peter A.
2016-01-01
Approved for public release; distribution is unlimited Each tragic shooting incident that the American news media covers highlights the problem of gun violence in the United States. However, the focus of this reporting is rarely on the largest component of total gun deaths: suicides. Suicides make up two-thirds of all gun deaths. Limiting access to firearms for individuals with suicidal tendencies could cause a significant reduction in the total number of casualties included in gun violenc...
Ground Control for Emplacement Drifts for LA
Energy Technology Data Exchange (ETDEWEB)
Y. Sun
2004-07-09
The purpose of this calculation is to analyze the stability of repository emplacement drifts during the preclosure period, and to provide a final ground support method for emplacement drifts for the License Application (LA). The scope of the work includes determination of input parameter values and loads, selection of appropriate process and methods for the calculation, application of selected methods, such as empirical or analytical, to the calculation, development and execution of numerical models, and evaluation of results. Results from this calculation are limited to use for design of the emplacement drifts and the final ground support system installed in these drifts. The design of non-emplacement openings and their ground support systems is covered in the ''Ground Control for Non-Emplacement Drifts for LA'' (BSC 2004c).
The growth of railway ground vibration problems - A review.
Connolly, David P; Marecki, Grzegorz P; Kouroussis, Georges; Thalassinakis, Ioannis; Woodward, Peter K
2016-10-15
Ground-borne noise and vibration from railway lines can cause human distress/annoyance, and also negatively affect real estate property values. Therefore this paper analyses a collection of technical ground-borne noise and vibration reports, detailing commercial vibration assessments undertaken at 1604 railway track sections, in 9 countries across the world. A wide range of rail projects are considered including light rail, tram lines, underground/tunnelled lines, freight, conventional rail and high speed rail. It documents the rise in ground-borne vibration problems and trends in the prediction industry, with the aim of informing the current research area. Firstly, the reports are analysed chronologically and it is found that railway vibration is a growing global concern, and as such, assessments have become more prevalent. International assessment metrics are benchmarked and it is found that velocity decibels (VdB), vibration dose value (VDV) and peak particle velocity (PPV) are the most commonly used methods of assessment. Furthermore, to predict vibration levels, the physical measurement of frequency transfer functions is preferential to numerical modelling. Results from the reports show that ground vibration limits are exceeded in 44% of assessments, and that ground-borne noise limits are exceeded in 31%. Moreover, mitigation measures were required on approximately 50% of projects, revealing that ground-borne noise and vibration is a widespread railroad engineering challenge. To solve these problems, the most commonly used abatement strategy is a modification of the railtrack structure (active mitigation), rather than the implementation of a more passive solution in the far-field. Copyright © 2015 Elsevier B.V. All rights reserved.
Directory of Open Access Journals (Sweden)
Ioannis Athanasopoulos
1984-01-01
Full Text Available In an open bounded region of n-space occupied by a homogeneous and isotropic medium, we control the temperature through the boundary. The normal derivative of the temperature (which measures the appropriate heat flux is restricted to be nonnegative. This gives rise to a free boundary in space-time separating the areas of positive and zero heat flux. Under a natural monotonicity condition, the free boundary is the graph of a function of space. This function is shown to be locally Lipschitz. Moreover for n=2 the time derivative of the temperature is proven to be continuous across the free boundary.
LABS problem and ground state spin glasses system
Leukhin, A. N.; Bezrodnyi, V. I.; Kozlova, Yu. A.
2016-12-01
In our work we demonstrate the new results of an exhaustive search for optimal binary sequences with minimum peak sidelobe (MPS) up to length N=85. The design problem for law autocorrelation binary sequences (LABS) is a notoriously difficult computational problem which is numbered as the problem number 005 in CSPLib. In statistical physics LABS problem can be interrepted as the energy of N iteracting Ising spins. This is a Bernasconi model. Due to this connection to physics we refer a binary sequence as one-dimensional spin lattice. At this assumption optimal binary sequences by merit factor (MF) criteria are the ground-state spin system without disorder which exhibits a glassy regime.
Ground test for vibration control demonstrator
Meyer, C.; Prodigue, J.; Broux, G.; Cantinaud, O.; Poussot-Vassal, C.
2016-09-01
In the objective of maximizing comfort in Falcon jets, Dassault Aviation is developing an innovative vibration control technology. Vibrations of the structure are measured at several locations and sent to a dedicated high performance vibration control computer. Control laws are implemented in this computer to analyse the vibrations in real time, and then elaborate orders sent to the existing control surfaces to counteract vibrations. After detailing the technology principles, this paper focuses on the vibration control ground demonstration that was performed by Dassault Aviation in May 2015 on Falcon 7X business jet. The goal of this test was to attenuate vibrations resulting from fixed forced excitation delivered by shakers. The ground test demonstrated the capability to implement an efficient closed-loop vibration control with a significant vibration level reduction and validated the vibration control law design methodology. This successful ground test was a prerequisite before the flight test demonstration that is now being prepared. This study has been partly supported by the JTI CleanSky SFWA-ITD.
Ground Control for Emplacement Drifts for SR
Energy Technology Data Exchange (ETDEWEB)
Y. Sun
2000-04-07
This analysis demonstrates that a satisfactory ground control system can be designed for the Yucca Mountain site, and provides the technical basis for the design of ground support systems to be used in repository emplacement and non-emplacement drifts. The repository ground support design was based on analytical methods using acquired computer codes, and focused on the final support systems. A literature review of case histories, including the lessons learned from the design and construction of the ESF, the studies on the seismic damages of underground openings, and the use of rock mass classification systems in the ground support design, was conducted (Sections 6.3.4 and 6.4). This review provided some basis for determining the inputs and methodologies used in this analysis. Stability of the supported and unsupported emplacement and non-emplacement drifts was evaluated in this analysis. The excavation effects (i.e., state of the stress change due to excavation), thermal effects (i.e., due to heat output from waste packages), and seismic effects (i.e., from potential earthquake events) were evaluated, and stress controlled modes of failure were examined for two in situ stress conditions (k_0=0.3 and 1.0) using rock properties representing rock mass categories of 1 and 5. Variation of rock mass units such as the non-lithophysal (Tptpmn) and lithophysal (Tptpll) was considered in the analysis. The focus was on the non-lithophysal unit because this unit appears to be relatively weaker and has much smaller joint spacing. Therefore, the drift stability and ground support needs were considered to be controlled by the design for this rock unit. The ground support systems for both emplacement and non-emplacement drifts were incorporated into the models to assess their performance under in situ, thermal, and seismic loading conditions. Both continuum and discontinuum modeling approaches were employed in the analyses of the rock mass behavior and in the evaluation of the
On the ground truth problem of malicious DNS traffic analysis
DEFF Research Database (Denmark)
Stevanovic, Matija; Pedersen, Jens Myrup; D’Alconzo, Alessandro
2015-01-01
DNS is often abused by Internet criminals in order to provide flexible and resilient hosting of malicious content and reliable communication within their network architecture. The majority of detection methods targeting alicious DNS traffic are data-driven, most commonly having machine learning...... algorithms at their core. These methods require accurate ground truth of both malicious and benign DNS traffic for model training as well as for the performance evaluation. This paper elaborates on the problem of obtaining such a ground truth and evaluates practices employed by contemporary detection methods....... Building upon the evaluation results, we propose a novel semi-manual labeling practice targeting agile DNS mappings, i.e. DNS queries that are used to reach a potentially malicious server characterized by fast changing domain names or/and IP addresses. The proposed approach is developed with the purpose...
FGMOS Based Voltage-Controlled Grounded Resistor
Directory of Open Access Journals (Sweden)
R. Pandey
2010-09-01
Full Text Available This paper proposes a new floating gate MOSFET (FGMOS based voltage-controlled grounded resistor. In the proposed circuit FGMOS operating in the ohmic region is linearized by another conventional MOSFET operating in the saturation region. The major advantages of FGMOS based voltage-controlled grounded resistor (FGVCGR are simplicity, low total harmonic distortion (THD, and low power consumption. A simple application of this FGVCGR as a tunable high-pass filter is also suggested. The proposed circuits operate at the supply voltages of +/-0.75 V. The circuits are designed and simulated using SPICE in 0.25-µm CMOS technology. The simulation results of FGVCGR demonstrate a THD of 0.28% for the input signal 0.32 Vpp at 45 kHz, and a maximum power consumption of 254 µW.
Solving the drift control problem
Directory of Open Access Journals (Sweden)
Melda Ormeci Matoglu
2015-12-01
Full Text Available We model the problem of managing capacity in a build-to-order environment as a Brownian drift control problem. We formulate a structured linear program that models a practical discretization of the problem and exploit a strong relationship between relative value functions and dual solutions to develop a functional lower bound for the continuous problem from a dual solution to the discrete problem. Refining the discretization proves a functional strong duality for the continuous problem. The linear programming formulation is so badly scaled, however, that solving it is beyond the capabilities of standard solvers. By demonstrating the equivalence between strongly feasible bases and deterministic unichain policies, we combinatorialize the pivoting process and by exploiting the relationship between dual solutions and relative value functions, develop a mechanism for solving the LP without ever computing its coefficients. Finally, we exploit the relationship between relative value functions and dual solutions to develop a scheme analogous to column generation for refining the discretization so as to drive the gap between the discrete approximation and the continuous problem to zero quickly while keeping the LP small. Computational studies show our scheme is much faster than simply solving a regular discretization of the problem both in terms of finding a policy with a low average cost and in terms of providing a lower bound on the optimal average cost.
Leibovich, Tali; Ansari, Daniel
2016-03-01
How do numerical symbols, such as number words, acquire semantic meaning? This question, also referred to as the "symbol-grounding problem," is a central problem in the field of numerical cognition. Present theories suggest that symbols acquire their meaning by being mapped onto an approximate system for the nonsymbolic representation of number (Approximate Number System or ANS). In the present literature review, we first asked to which extent current behavioural and neuroimaging data support this theory, and second, to which extent the ANS, upon which symbolic numbers are assumed to be grounded, is numerical in nature. We conclude that (a) current evidence that has examined the association between the ANS and number symbols does not support the notion that number symbols are grounded in the ANS and (b) given the strong correlation between numerosity and continuous variables in nonsymbolic number processing tasks, it is next to impossible to measure the pure association between symbolic and nonsymbolic numerosity. Instead, it is clear that significant cognitive control resources are required to disambiguate numerical from continuous variables during nonsymbolic number processing. Thus, if there exists any mapping between the ANS and symbolic number, then this process of association must be mediated by cognitive control. Taken together, we suggest that studying the role of both cognitive control and continuous variables in numerosity comparison tasks will provide a more complete picture of the symbol-grounding problem.
DEFF Research Database (Denmark)
Wang, Wen; Zeng, Xiangjun; Yan, Lingjie;
2017-01-01
Traditional ground-fault arc suppression devices mainly deal with capacitive component of ground current and have weak effect on the active and harmonic ones, which limits the arc suppression performance. The capacitive current detection needed in them suffers from low accuracy and robustness....... The commonly-used large-capacity reactive component may bring about overvoltage because of possible resonance with the distributed phase-to-ground capacitance. To solve these problems, an active ground-fault arc suppression device is presented. It employs a topology based on single-phase inverter to inject...... current into the neutral without any large-capacity reactors, and thus avoids the aforementioned overvoltage. It compensates all the active, reactive and harmonic components of the ground current to reliably extinguish the ground-fault arcs. A dual-loop voltage control method is proposed to realize arc...
How Does Measuring Generate Evidence? The Problem of Observational Grounding
Tal, Eran
2016-11-01
The epistemology of measurement is an area of philosophy that studies the relationships between measurement and knowledge. One of its central aims is to explain how measurement can function as a reliable source of scientific evidence. Key to such explanation is a clear characterization of the dependence of measurement on observation, but such characterization has remained elusive. This article traces the recent historical trajectory of views on the observational grounding of measurement, clarifies the current state of the problem, and proposes new directions for progress. Specifically, I argue in favour of viewing measurement outcomes as the best predictors of observed instrument indications under a given theoretical-statistical model of the measurement process. The evidential efficacy of measurement outcomes is explained by their relatively high epistemic security, rather than by their inferential or structural closeness to observation.
Automatic Scheduling and Planning (ASAP) in future ground control systems
Matlin, Sam
1988-01-01
This report describes two complementary approaches to the problem of space mission planning and scheduling. The first is an Expert System or Knowledge-Based System for automatically resolving most of the activity conflicts in a candidate plan. The second is an Interactive Graphics Decision Aid to assist the operator in manually resolving the residual conflicts which are beyond the scope of the Expert System. The two system designs are consistent with future ground control station activity requirements, support activity timing constraints, resource limits and activity priority guidelines.
An Integrated Approach to the Ground Crew Rostering Problem with Work Patterns
DEFF Research Database (Denmark)
Lusby, Richard Martin; Hansen, Anders Dohn; Range, Troels Martin;
This paper addresses the Ground Crew Rostering Problem with Work Patterns, an important manpower planning problem arising in the ground operations of airline companies. We present a cutting stock based integer programming formulation of the problem and describe a powerful decomposition approach...
2015-09-01
GPS Actions Needed to Address Ground System Development Problems and User Equipment Production Readiness Report to...00-00-2015 to 00-00-2015 4. TITLE AND SUBTITLE GPS : Actions Needed to Address Ground System Development Problems and User Equipment Production...Highlights of GAO-15-657, a report to congressional committees September 2015 GPS Actions Needed to Address Ground System Development Problems and User
Optimal impulse control problems and linear programming.
Bauso, D.
2009-01-01
Optimal impulse control problems are, in general, difficult to solve. A current research goal is to isolate those problems that lead to tractable solutions. In this paper, we identify a special class of optimal impulse control problems which are easy to solve. Easy to solve means that solution algorithms are polynomial in time and therefore suitable to the on-line implementation in real-time problems. We do this by using a paradigm borrowed from the Operations Research field. As main result, ...
Bladder Control Problems in Women
... floor muscles (left) and weak pelvic floor muscles (right) A woman may be born with factors that increase her ... urinary problems, and recurrence of incontinence. 6 Each woman should speak ... any, is right for her. Urgency Incontinence Women who have urgency ...
Trade-offs between grounded and abstract representations: evidence from algebra problem solving.
Koedinger, Kenneth R; Alibali, Martha W; Nathan, Mitchell J
2008-03-01
This article explores the complementary strengths and weaknesses of grounded and abstract representations in the domain of early algebra. Abstract representations, such as algebraic symbols, are concise and easy to manipulate but are distanced from any physical referents. Grounded representations, such as verbal descriptions of situations, are more concrete and familiar, and they are more similar to physical objects and everyday experience. The complementary computational characteristics of grounded and abstract representations lead to trade-offs in problem-solving performance. In prior research with high school students solving relatively simple problems, Koedinger and Nathan (2004) demonstrated performance benefits of grounded representations over abstract representations-students were better at solving simple story problems than the analogous equations. This article extends this prior work to examine both simple and more complex problems in two samples of college students. On complex problems with two references to the unknown, a "symbolic advantage" emerged, such that students were better at solving equations than analogous story problems. Furthermore, the previously observed "verbal advantage" on simple problems was replicated. We thus provide empirical support for a trade-off between grounded, verbal representations, which show advantages on simpler problems, and abstract, symbolic representations, which show advantages on more complex problems.
The Propulsive-Only Flight Control Problem
Blezad, Daniel J.
1996-01-01
Attitude control of aircraft using only the throttles is investigated. The long time constants of both the engines and of the aircraft dynamics, together with the coupling between longitudinal and lateral aircraft modes make piloted flight with failed control surfaces hazardous, especially when attempting to land. This research documents the results of in-flight operation using simulated failed flight controls and ground simulations of piloted propulsive-only control to touchdown. Augmentation control laws to assist the pilot are described using both optimal control and classical feedback methods. Piloted simulation using augmentation shows that simple and effective augmented control can be achieved in a wide variety of failed configurations.
De-tabooing dying control - a grounded theory study
National Research Council Canada - National Science Library
Thulesius, Hans O; Scott, Helen; Helgesson, Gert; Lynöe, Niels
2013-01-01
...?" 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...
Discrete Control Processes, Dynamic Games and Multicriterion Control Problems
Directory of Open Access Journals (Sweden)
Dumitru Lozovanu
2002-07-01
Full Text Available The discrete control processes with state evaluation in time of dynamical system is considered. A general model of control problems with integral-time cost criterion by a trajectory is studied and a general scheme for solving such classes of problems is proposed. In addition the game-theoretical and multicriterion models for control problems are formulated and studied.
Predator control problems in Alaska
US Fish and Wildlife Service, Department of the Interior — One of the important wildlife management activities in Alaska is that of predator control. This simple statement requires some explanation. In the course of these...
Bladder Control Problems in Men
... special sensors to measure bodily functions, such as muscle contractions that control urination. A video monitor displays the ... symptoms of urgency incontinence. Mirabegron suppresses involuntary bladder ... brain signals the muscular bladder wall to tighten, squeezing urine out of ...
OPTIMAL CONTROL PROBLEM FOR PARABOLIC VARIATIONAL INEQUALITIES
Institute of Scientific and Technical Information of China (English)
汪更生
2001-01-01
This paper deals with the optimal control problems of systems governed by a parabolic variational inequality coupled with a semilinear parabolic differential equations.The maximum principle and some kind of approximate controllability are studied.
Optimal control problems with switching points
Seywald, Hans
1991-09-01
An overview is presented of the problems and difficulties that arise in solving optimal control problems with switching points. A brief discussion of existing optimality conditions is given and a numerical approach for solving the multipoint boundary value problems associated with the first-order necessary conditions of optimal control is presented. Two real-life aerospace optimization problems are treated explicitly. These are altitude maximization for a sounding rocket (Goddard Problem) in the presence of a dynamic pressure limit, and range maximization for a supersonic aircraft flying in the vertical, also in the presence of a dynamic pressure limit. In the second problem singular control appears along arcs with active dynamic pressure limit, which in the context of optimal control, represents a first-order state inequality constraint. An extension of the Generalized Legendre-Clebsch Condition to the case of singular control along state/control constrained arcs is presented and is applied to the aircraft range maximization problem stated above. A contribution to the field of Jacobi Necessary Conditions is made by giving a new proof for the non-optimality of conjugate paths in the Accessory Minimum Problem. Because of its simple and explicit character, the new proof may provide the basis for an extension of Jacobi's Necessary Condition to the case of the trajectories with interior point constraints. Finally, the result that touch points cannot occur for first-order state inequality constraints is extended to the case of vector valued control functions.
Ozone Control Strategies | Ground-level Ozone | New ...
2017-02-16
The Air Quality Planning Unit's primary goal is to protect your right to breathe clean air. Guided by the Clean Air Act, we work collaboratively with states, communities, and businesses to develop and implement strategies to reduce air pollution from a variety of sources that contribute to the ground-level ozone or smog problem.
A Quarter Active Suspension System Based Ground-Hook Controller
Turnip Arjon
2016-01-01
An alternative design technique for active suspension system of vehicle using a developved ground-hook damping system as a reference is proposed. The controller parameters are determined using Lyapunov method and can be tuned to precisely achieve the type of desired response which given by reference model. The simulation result show that the designed active suspension system based ground-hook reference model is able to significantly improve the ride comfort and the road holding compared with ...
A Ground Control Station for the UAV Flight Simulator
Directory of Open Access Journals (Sweden)
Romaniuk Sławomir
2016-03-01
Full Text Available In the paper implementation of a ground control station for UAV flight simulator is shown. The ground control station software is in cooperation with flight simulator, displaying various aircraft flight parameters. The software is programmed in C++ language and utilizes the windows forms for implementing graphical content. One of the main aims of the design of the application was to simplify the interface, simultaneously maintaining the functionality and the eligibility. A mission can be planned and monitored using the implemented map control supported by waypoint list.
The Spartan attitude control system - Ground support computer
Schnurr, R. G., Jr.
1986-01-01
The Spartan Attitude Control System (ACS) contains a command and control computer. This computer is optimized for the activities of the flight and contains very little human interface hardware and software. The computer system provides the technicians testing of Spartan ACS with a convenient command-oriented interface to the flight ACS computer. The system also decodes and time tags data automatically sent out by the flight computer as key events occur. The duration and magnitude of all system maneuvers is also derived and displayed by this system. The Ground Support Computer is also the primary Ground Support Equipment for the flight sequencer which controls all payload maneuvers, and long term program timing.
Control and learning for intelligent mobility of unmanned ground vehicles in complex terrains
Trentini, M.; Beckman, B.; Digney, B.
2005-05-01
The Autonomous Intelligent Systems program at Defence R&D Canada-Suffield envisions autonomous systems contributing to decisive operations in the urban battle space. Creating effective intelligence for these systems demands advances in perception, world representation, navigation, and learning. In the land environment, these scientific areas have garnered much attention, while largely ignoring the problem of locomotion in complex terrain. This is a gap in robotics research, where sophisticated algorithms are needed to coordinate and control robotic locomotion in unknown, highly complex environments. Unlike traditional control problems, intuitive and systematic control tools for robotic locomotion do not readily exist thus limiting their practical application. This paper addresses the mobility problem for unmanned ground vehicles, defined here as the autonomous maneuverability of unmanned ground vehicles in unknown, highly complex environments. It discusses the progress and future direction of intelligent mobility research at Defence R&D Canada-Suffield and presents the research tools, topics and plans to address this critical research gap.
Solved problems in dynamical systems and control
Tenreiro-Machado, J; Valério, Duarte; Galhano, Alexandra M
2016-01-01
This book presents a collection of exercises on dynamical systems, modelling and control. Each topic covered includes a summary of the theoretical background, problems with solutions, and further exercises.
Fast Solvers of Fredholm Optimal Control Problems
Institute of Scientific and Technical Information of China (English)
Mario; Borzì
2010-01-01
The formulation of optimal control problems governed by Fredholm integral equations of second kind and an efficient computational framework for solving these control problems is presented. Existence and uniqueness of optimal solutions is proved.A collective Gauss-Seidel scheme and a multigrid scheme are discussed. Optimal computational performance of these iterative schemes is proved by local Fourier analysis and demonstrated by results of numerical experiments.
Tractable problems in optimal decentralized control
Rotkowitz, Michael Charles
2005-07-01
This thesis considers the problem of constructing optimal decentralized controllers. The problem is formulated as one of minimizing the closed-loop norm of a feedback system subject to constraints on the controller structure. The notion of quadratic invariance of a constraint set with respect to a system is defined. It is shown that quadratic invariance is necessary and sufficient for the constraint set to be preserved under feedback. It is further shown that if the constraint set has this property, this allows the constrained minimum-norm problem to be solved via convex programming. These results are developed in a very general framework, and are shown to hold for continuous-time systems, discrete-time systems, or operators on Banach spaces, for stable or unstable plants, and for the minimization of any norm. The utility of these results is then demonstrated on some specific constraint classes. An explicit test is derived for sparsity constraints on a controller to be quadratically invariant, and thus amenable to convex synthesis. Symmetric synthesis is also shown to be quadratically invariant. The problem of control over networks with delays is then addressed as another constraint class. Multiple subsystems are considered, each with its own controller, such that the dynamics of each subsystem may affect those of other subsystems with some propagation delays, and the controllers may communicate with each other with some transmission delays. It is shown that if the communication delays are less than the propagation delays, then the associated constraints are quadratically invariant, and thus optimal controllers can be synthesized. We further show that this result still holds in the presence of computational delays. This thesis unifies the few previous results on specific tractable decentralized control problems, identifies broad and useful classes of new solvable problems, and delineates the largest known class of convex problems in decentralized control.
Regional ground deformation and its controlling measures in China
Zhou, Zhifang; Zhu, Haisheng; Huang, Yong
2006-12-01
With the development of construction of China Cities, there exist a lot of environmental geological problems involved in the geofracture, land subsidence, collapse, landslide, devolution, mudrock flow, floating sand, piping and soft ground deformation. Of big cities whose population is over one million in China, about 30 cities appears the land subsidence region. Other cities locate in the regions of collapse yellow earth or expand soil of strong swell-shrink charasteristic, soft ground and karst. In the paper, the cause and hazard of regionality ground deformation is summed up. The causes of regional land deformation caused by the natural geological effect and activities of human being are analyzed. According to the length of deformation course and endanger of society, economy and life, land deformation involves three types, that is, the delay, rapid and break land deformation. And the concrete countermeasure and method are provided.
Ground controlled robotic assembly operations for Space Station Freedom
Parrish, Joseph C.
1991-01-01
A number of dextrous robotic systems and associated positioning and transportation devices are available on Space Station Freedom (SSF) to perform assembly tasks that would otherwise need to be performed by extravehicular activity (EVA) crewmembers. The currently planned operating mode for these robotic systems during the assembly phase is teleoperation by intravehicular activity (IVA) crewmembers. While this operating mode is less hazardous and expensive than manned EVA operations, and has insignificant control loop time delays, the amount of IVA time available to support telerobotic operations is much less than the anticipated requirements. Some alternative is needed to allow the robotic systems to perform useful tasks without exhausting the available IVA resources; ground control is one such alternative. The issues associated with ground control of SSF robotic systems to alleviate onboard crew time availability constraints are investigated. Key technical issues include the effect of communication time delays, the need for safe, reliable execution of remote operations, and required modifications to the SSF ground and flight system architecture. Time delay compensation techniques such as predictive displays and world model-based force reflection are addressed and collision detection and avoidance strategies to ensure the safety of the on-orbit crew, Orbiter, and SSF are described. Although more time consuming and difficult than IVA controlled teleoperations or manned EVA, ground controlled telerobotic operations offer significant benefits during the SSF assembly phase, and should be considered in assembly planning activities.
Minimal Time Problem with Impulsive Controls
Energy Technology Data Exchange (ETDEWEB)
Kunisch, Karl, E-mail: karl.kunisch@uni-graz.at [University of Graz, Institute for Mathematics and Scientific Computing (Austria); Rao, Zhiping, E-mail: zhiping.rao@ricam.oeaw.ac.at [Austrian Academy of Sciences, Radon Institute of Computational and Applied Mathematics (Austria)
2017-02-15
Time optimal control problems for systems with impulsive controls are investigated. Sufficient conditions for the existence of time optimal controls are given. A dynamical programming principle is derived and Lipschitz continuity of an appropriately defined value functional is established. The value functional satisfies a Hamilton–Jacobi–Bellman equation in the viscosity sense. A numerical example for a rider-swing system is presented and it is shown that the reachable set is enlargered by allowing for impulsive controls, when compared to nonimpulsive controls.
A Dynamic Programming-Based Heuristic for the Shift Design Problem in Airport Ground Handling
DEFF Research Database (Denmark)
Clausen, Tommy
We consider the heterogeneous shift design problem for a workforce with multiple skills, where work shifts are created to cover a given demand as well as possible while minimizing cost and satisfying a flexible set of constraints. We focus mainly on applications within airport ground handling where...... the demand can be highly irregular and specified on time intervals as short as five minutes. Ground handling operations are subject to a high degree of cooperation and specialization that require workers with different qualifications to be planned together. Different labor regulations or organizational rules...... can apply to different ground handling operations, so the rules and restrictions can be numerous and vary significantly. This is modeled using flexible volume constraints that limit the creation of certain shifts. We present a fast heuristic for the heterogeneous shift design problem based on dynamic...
A Quarter Active Suspension System Based Ground-Hook Controller
Directory of Open Access Journals (Sweden)
Turnip Arjon
2016-01-01
Full Text Available An alternative design technique for active suspension system of vehicle using a developved ground-hook damping system as a reference is proposed. The controller parameters are determined using Lyapunov method and can be tuned to precisely achieve the type of desired response which given by reference model. The simulation result show that the designed active suspension system based ground-hook reference model is able to significantly improve the ride comfort and the road holding compared with semi-active suspension.
Active control of shocks and sonic boom ground signal
Yagiz, Bedri
The manipulation of a flow field to obtain a desired change is a much heightened subject. Active flow control has been the subject of the major research areas in fluid mechanics for the past two decades. It offers new solutions for mitigation of shock strength, sonic boom alleviation, drag minimization, reducing blade-vortex interaction noise in helicopters, stall control and the performance maximization of existing designs to meet the increasing requirements of the aircraft industries. Despite the wide variety of the potential applications of active flow control, the majority of studies have been performed at subsonic speeds. The active flow control cases were investigated in transonic speed in this study. Although the active flow control provides significant improvements, the sensibility of aerodynamic performance to design parameters makes it a nontrivial and expensive problem, so the designer has to optimize a number of different parameters. For the purpose of gaining understanding of the active flow control concepts, an automated optimization cycle process was generated. Also, the optimization cycle reduces cost and turnaround time. The mass flow coefficient, location, width and angle were chosen as design parameters to maximize the aerodynamic performance of an aircraft. As the main contribution of this study, a detailed parametric study and optimization process were presented. The second step is to appraise the practicability of weakening the shock wave and thereby reducing the wave drag in transonic flight regime using flow control devices such as two dimensional contour bump, individual jet actuator, and also the hybrid control which includes both control devices together, thereby gaining the desired improvements in aerodynamic performance of the air-vehicle. After this study, to improve the aerodynamic performance, the flow control and shape parameters are optimized separately, combined, and in a serial combination. The remarkable part of all these
Hybrid Predictive Control for Dynamic Transport Problems
Núñez, Alfredo A; Cortés, Cristián E
2013-01-01
Hybrid Predictive Control for Dynamic Transport Problems develops methods for the design of predictive control strategies for nonlinear-dynamic hybrid discrete-/continuous-variable systems. The methodology is designed for real-time applications, particularly the study of dynamic transport systems. Operational and service policies are considered, as well as cost reduction. The control structure is based on a sound definition of the key variables and their evolution. A flexible objective function able to capture the predictive behaviour of the system variables is described. Coupled with efficient algorithms, mainly drawn from the area of computational intelligence, this is shown to optimize performance indices for real-time applications. The framework of the proposed predictive control methodology is generic and, being able to solve nonlinear mixed-integer optimization problems dynamically, is readily extendable to other industrial processes. The main topics of this book are: ●hybrid predictive control (HPC) ...
Maximum process problems in optimal control theory
Directory of Open Access Journals (Sweden)
Goran Peskir
2005-01-01
Full Text Available Given a standard Brownian motion (Btt≥0 and the equation of motion dXt=vtdt+2dBt, we set St=max0≤s≤tXs and consider the optimal control problem supvE(Sτ−Cτ, where c>0 and the supremum is taken over all admissible controls v satisfying vt∈[μ0,μ1] for all t up to τ=inf{t>0|Xt∉(ℓ0,ℓ1} with μ0g∗(St, where s↦g∗(s is a switching curve that is determined explicitly (as the unique solution to a nonlinear differential equation. The solution found demonstrates that the problem formulations based on a maximum functional can be successfully included in optimal control theory (calculus of variations in addition to the classic problem formulations due to Lagrange, Mayer, and Bolza.
Quantum speed problem: Theoretical hints for control
Lisboa, Alexandre Coutinho; Piqueira, José Roberto Castilho
2016-06-01
The transition time between states plays an important role in designing quantum devices as they are very sensitive to environmental influences. Decoherence phenomenon is responsible for possible destructions of the entanglement that is a fundamental requirement to implement quantum information processing systems. If the time between states is minimized, the decoherence effects can be reduced, thus, it is advantageous to the designer to develop expressions for time performance measures. Quantum speed limit (QSL) problem has been studied from the theoretical point of view, providing general results. Considering the implementation of quantum control systems, as the decoherence phenomenon is unavoidable, it is important to apply these general results to particular cases, developing expressions and performance measures, to assist control engineering designers. Here, a minimum time performance measure is defined for quantum control problems, for time-independent or time-dependent Hamiltonians, and applied to some practical examples, providing hints that may be useful for researchers pursuing optimization strategies for quantum control systems.
Close-range photogrammetry in underground mining ground control
Benton, Donovan J.; Chambers, Amy J.; Raffaldi, Michael J.; Finley, Seth A.; Powers, Mark J.
2016-09-01
Monitoring underground mine deformation and support conditions has traditionally involved visual inspection and geotechnical instrumentation. Monitoring displacements with conventional instrumentation can be expensive and time-consuming, and the number of locations that can be effectively monitored is generally limited. Moreover, conventional methods typically produce vector rather than tensor descriptions of geometry changes. Tensor descriptions can provide greater insight into hazardous ground movements, particularly in recently excavated openings and in older workings that have been negatively impacted by high stress concentrations, time-dependent deformation, or corrosion of ground support elements. To address these issues, researchers with the National Institute for Occupational Safety and Health, Spokane Mining Research Division are developing and evaluating photogrammetric systems for ground control monitoring applications in underground mines. This research has demonstrated that photogrammetric systems can produce millimeter-level measurements that are comparable to conventional displacement-measuring instruments. This paper provides an overview of the beneficial use of close-range photogrammetry for the following three ground control applications in underground mines: monitoring the deformation of surface support, monitoring rock mass movement, and monitoring the corrosion of surface support. Preliminary field analyses, case studies, limitations, and best practices for these applications are also discussed.
Coherent Control of Ground State NaK Molecules
Yan, Zoe; Park, Jee Woo; Loh, Huanqian; Will, Sebastian; Zwierlein, Martin
2016-05-01
Ultracold dipolar molecules exhibit anisotropic, tunable, long-range interactions, making them attractive for the study of novel states of matter and quantum information processing. We demonstrate the creation and control of 23 Na40 K molecules in their rovibronic and hyperfine ground state. By applying microwaves, we drive coherent Rabi oscillations of spin-polarized molecules between the rotational ground state (J=0) and J=1. The control afforded by microwave manipulation allows us to pursue engineered dipolar interactions via microwave dressing. By driving a two-photon transition, we are also able to observe Ramsey fringes between different J=0 hyperfine states, with coherence times as long as 0.5s. The realization of long coherence times between different molecular states is crucial for applications in quantum information processing. NSF, AFOSR- MURI, Alfred P. Sloan Foundation, DARPA-OLE
Problems in event based engine control
DEFF Research Database (Denmark)
Hendricks, Elbert; Jensen, Michael; Chevalier, Alain Marie Roger
1994-01-01
Physically a four cycle spark ignition engine operates on the basis of four engine processes or events: intake, compression, ignition (or expansion) and exhaust. These events each occupy approximately 180° of crank angle. In conventional engine controllers, it is an accepted practice to sample...... the engine variables synchronously with these events (or submultiples of them). Such engine controllers are often called event-based systems. Unfortunately the main system noise (or disturbance) is also synchronous with the engine events: the engine pumping fluctuations. Since many electronic engine...... problems on accurate air/fuel ratio control of a spark ignition (SI) engine....
TBM tunneling in mixed-face ground:Problems and solutions
Institute of Scientific and Technical Information of China (English)
Ma Hongsu; Yin Lijun; Gong Qiuming; Wang Ju
2015-01-01
Mixed-face ground encountered in Tunnel Boring Machine (TBM) tunneling presents great challenges and may trigger potential hazards without warning. A detailed understanding of such unfavorable con-ditions is therefore critical to a successful bored tunnel. In this paper, we firstly present a brief review of the definition, classification and the factors related to mixed-face conditions. Secondly, for a better understanding of this topic, we investigate the main difficulties and problems involved in TBM tun-nelling under mixed-face ground with detailed cases. Thirdly, from the viewpoint of rock-machine interaction, we give some suggestions on the corresponding mitigation measurements from three cat-egories: (i) selection of TBM type and modification of TBM, (ii) condition of ground and (iii) optimiza-tion of TBM operation.
Modeling and control for hydraulic transmission of unmanned ground vehicle
Institute of Scientific and Technical Information of China (English)
王岩; 张泽; 秦绪情
2014-01-01
Variable pump driving variable motor (VPDVM) is the future development trend of the hydraulic transmission of an unmanned ground vehicle (UGV). VPDVM is a dual-input single-output nonlinear system with coupling, which is difficult to control. High pressure automatic variables bang-bang (HABB) was proposed to achieve the desired motor speed. First, the VPDVM nonlinear mathematic model was introduced, then linearized by feedback linearization theory, and the zero-dynamic stability was proved. The HABB control algorithm was proposed for VPDVM, in which the variable motor was controlled by high pressure automatic variables (HA) and the variable pump was controlled by bang-bang. Finally, simulation of VPDVM controlled by HABB was developed. Simulation results demonstrate the HABB can implement the desired motor speed rapidly and has strong robustness against the variations of desired motor speed, load and pump speed.
Problems of substance abuse: exploitation and control.
Ray, L
1985-01-01
The notion of substance abuse is highly problematic. There is considerable disagreement amongst 'experts' as to the relative hazards and addictive properties of both legally and illegally available substances. There are also widely divergent sub-cultural attitudes to the harmfulness or benefit of drug use. One can assume no social consensus as to the nature of the contemporary 'drug problem', nor about the most appropriate means of dealing with it. There is, however, considerable evidence that criminalization of drug use, and harsh penalties against users and suppliers, are ineffective and counter-productive. Other models of control need to be considered, and in particular the merits and de-merits of the medicalization of drug abuse require examination. However, this is only one aspect of the problem. On the other side are the national and international corporations and syndicates, both legitimate and criminal, that earn vast profits from trade in toxic substances. Tobacco is legally available in every country in the world, and the industry is rarely subject to strict control. Thus the issue of substance abuse and control should be seen in a global context, in which account is taken of both legitimate and underworld operations. In attempts to control international trade in toxic substances, the limited success and the problems of already existing legal controls should be acknowledged. Local awareness and regulation of trade in substances is essential, but not sufficient. Amongst other avenues to be explored is the possibility of diverting presently illicitly grown narcotics into indigenous pharmaceutical industries in the Third World. Some problems with this strategy are noted.(ABSTRACT TRUNCATED AT 250 WORDS)
Remote control of a small unmanned ground vehicle (SUGV)
Irimie, Nicolae; Zorila, Alexandru; Nan, Alexandru; Schiopu, Paul
2010-11-01
Developing robot technology has gained an increasing dynamics. Small unmanned ground vehicle - SUGV has gained a place in the robotics field. This paper describes the possibility of remote control of the SUGV using a fuzzy algorithm. This designed algorithm specifically for controlling of a semi-autonomous mobile robot for research, observation, and surveillance. The device can provide 360-degree panoramic images using an image system which includes a hyperboloid mirror and a CCD camera, designed for this specific purpose. Both components, fuzzy algorithm and image system were implemented, tested in the laboratory condition and outdoor on a mobile robot for research, observation, and surveillance.
On the Optimal Controller for LTV Measurement Feedback Control Problem
Institute of Scientific and Technical Information of China (English)
Ting GONG; Yu Feng LU
2011-01-01
In this paper, we consider the measurement feedback control problem for discrete linear time-varying systems within the framework of nest algebra consisting of causal and bounded linear operators. Based on the inner-outer factorization of operators, we reduce the control problem to a distance from a certain operator to a special subspace of a nest algebra and show the existence of the optimal LTV controller in two different ways: one via the characteristic of the subspace in question directly, the other via the duality theory. The latter also gives a new formula for computing the optimal cost.
The Problem of Calculating Ground Freezing (K Voprosu Rascheta Promerzaniya Grunta),
1977-02-01
Proskuryakov . Greber (1] formulates the problem which was previously solved • Stefan, as follows: 1 “at the initial moment in time all points of a humid soil...depth of the ground becomes non-uniform , and cannot be averaged . I. A. Charnyy [3] and B. V. Proskuryakov [4] have developed simplified analytical...to unity, according to Charnyy has the following form: (13) and according to Proskuryakov it has the form ( 14 ) 3This drawback is alleviated by
Ground Operations Autonomous Control and Integrated Health Management
Daniels, James
2014-01-01
The Ground Operations Autonomous Control and Integrated Health Management plays a key role for future ground operations at NASA. The software that is integrated into this system is called G2 2011 Gensym. The purpose of this report is to describe the Ground Operations Autonomous Control and Integrated Health Management with the use of the G2 Gensym software and the G2 NASA toolkit for Integrated System Health Management (ISHM) which is a Computer Software Configuration Item (CSCI). The decision rationale for the use of the G2 platform is to develop a modular capability for ISHM and AC. Toolkit modules include knowledge bases that are generic and can be applied in any application domain module. That way, there's a maximization of reusability, maintainability, and systematic evolution, portability, and scalability. Engine modules are generic, while application modules represent the domain model of a specific application. Furthermore, the NASA toolkit, developed since 2006 (a set of modules), makes it possible to create application domain models quickly, using pre-defined objects that include sensors and components libraries for typical fluid, electrical, and mechanical systems.
Control problems in very large accelerators
Energy Technology Data Exchange (ETDEWEB)
Crowley-Milling, M.C.
1985-06-01
There is no fundamental difference of kind in the control requirements between a small and a large accelerator since they are built of the same types of components, which individually have similar control inputs and outputs. The main difference is one of scale; the large machine has many more components of each type, and the distances involved are much greater. Both of these factors must be taken into account in determining the optimum way of carrying out the control functions. Small machines should use standard equipment and software for control as much as possible, as special developments for small quantities cannot normally be justified if all costs are taken into account. On the other hand, the very great number of devices needed for a large machine means that, if special developments can result in simplification, they may make possible an appreciable reduction in the control equipment costs. It is the purpose of this report to look at the special control problems of large accelerators, which the author shall arbitarily define as those with a length of circumference in excess of 10 km, and point out where special developments, or the adoption of developments from outside the accelerator control field, can be of assistance in minimizing the cost of the control system. Most of the first part of this report was presented as a paper to the 1985 Particle Accelerator Conference. It has now been extended to include a discussion on the special case of the controls for the SSC.
A Rule-Based Local Search Algorithm for General Shift Design Problems in Airport Ground Handling
DEFF Research Database (Denmark)
Clausen, Tommy
We consider a generalized version of the shift design problem where shifts are created to cover a multiskilled demand and fit the parameters of the workforce. We present a collection of constraints and objectives for the generalized shift design problem. A local search solution framework with mul...... with multiple neighborhoods and a loosely coupled rule engine based on simulated annealing is presented. Computational experiments on real-life data from various airport ground handling organization show the performance and flexibility of the proposed algorithm....
SILEX ground segment control facilities and flight operations
Demelenne, Benoit; Tolker-Nielsen, Toni; Guillen, Jean-Claude
1999-04-01
The European Space Agency is going to conduct an inter orbit link experiment which will connect a low Earth orbiting satellite and a Geostationary satellite via optical terminals. This experiment has been called SILEX (Semiconductor Inter satellite Link Experiment). Two payloads have been built. One called PASTEL (PASsager de TELecommunication) has been embarked on the French Earth observation satellite SPOT4 which has been launched successfully in March 1998. The future European experimental data relay satellite ARTEMIS (Advanced Relay and TEchnology MISsion), which will route the data to ground, will carry the OPALE terminal (Optical Payload Experiment). The European Space Agency is responsible for the operation of both terminals. Due to the complexity and experimental character of this new optical technology, the development, preparation and validation of the ground segment control facilities required a long series of technical and operational qualification tests. This paper is presenting the operations concept and the early results of the PASTEL in orbit operations.
Mesh refinement strategy for optimal control problems
Paiva, Luis Tiago; Fontes, Fernando,
2013-01-01
International audience; Direct methods are becoming the most used technique to solve nonlinear optimal control problems. Regular time meshes having equidistant spacing are frequently used. However, in some cases these meshes cannot cope accurately with nonlinear behavior. One way to improve the solution is to select a new mesh with a greater number of nodes. Another way, involves adaptive mesh refinement. In this case, the mesh nodes have non equidistant spacing which allow a non uniform node...
Optimal Opinion Control: The Campaign Problem
2015-01-01
Opinion dynamics is nowadays a very common field of research. In this article we formulate and then study a novel, namely strategic perspective on such dynamics: There are the usual normal agents that update their opinions, for instance according the well-known bounded confidence mechanism. But, additionally, there is at least one strategic agent. That agent uses opinions as freely selectable strategies to get control on the dynamics: The strategic agent of our benchmark problem tries, during...
Dynamic Teams and Decentralized Control Problems with Substitutable Actions
Asghari, Seyed Mohammad; Nayyar, Ashutosh
2016-01-01
This paper considers two problems -- a dynamic team problem and a decentralized control problem. The problems we consider do not belong to the known classes of "simpler" dynamic team/decentralized control problems such as partially nested or quadratically invariant problems. However, we show that our problems admit simple solutions under an assumption referred to as the substitutability assumption. Intuitively, substitutability in a team (resp. decentralized control) problem means that the ef...
Airline Operational Control (AOC)/UAS Ground Control Station (GCS) Collaboration Project
National Aeronautics and Space Administration — We propose to form a network and a set of tools that will create a shared situation awareness with Unmanned Aircraft Systems (UAS) Ground Control Stations (GCSs) and...
Theisen, Bernard L.; Frederick, Philip; Smuda, William
2011-01-01
The Intelligent Ground Vehicle Competition (IGVC) is one of four, unmanned systems, student competitions that were founded by the Association for Unmanned Vehicle Systems International (AUVSI). The IGVC is a multidisciplinary exercise in product realization that challenges college engineering student teams to integrate advanced control theory, machine vision, vehicular electronics and mobile platform fundamentals to design and build an unmanned system. Teams from around the world focus on developing a suite of dual-use technologies to equip ground vehicles of the future with intelligent driving capabilities. Over the past 18 years, the competition has challenged undergraduate, graduate and Ph.D. students with real world applications in intelligent transportation systems, the military and manufacturing automation. To date, teams from over 75 universities and colleges have participated. This paper describes some of the applications of the technologies required by this competition and discusses the educational benefits. The primary goal of the IGVC is to advance engineering education in intelligent vehicles and related technologies. The employment and professional networking opportunities created for students and industrial sponsors through a series of technical events over the four-day competition are highlighted. Finally, an assessment of the competition based on participation is presented.
Microcontroller based ground weapon control system(Short Communication
Directory of Open Access Journals (Sweden)
M. Sankar Kishore
2001-10-01
Full Text Available Armoured vehicles and tanks generally consist of high resolution optical (both infrared and visible and display systems for recognition and identification of the targets. Different weapons/articles to engage the targets may be present. A fire control system (FCS controls all the above systems, monitors the status of the articles present and passes the information to the display system. Depending upon the health and availability of the articles, the FCS selects and fires the articles. Design and development of ground control unit which is the heart of the FCS, both in hardware and software, has been emphasised. The system has been developed using microcontroller and software developed in ASM 51 language. The system also has a facility to test all the systems and articles as initial power on condition. From the safety point of view, software and hardware interlocks have been provided in the critical operations, like firing sequence. "
Simultaneous Planning and Control for Autonomous Ground Vehicles
2009-02-01
obstacle avoidance were not part of the problem. Pioneering work was done by Dubins during the late 1950’s. He proved that optimal paths connecting a car...motion. Reeds and Shepp extended the work of Dubins to include motion for a vehicle traveling both forwards and backwards [REE91]. There are several...use of receding horizon control for electro -mechanical systems. This limitation is primarily due to the time critical nature of the required control
Simulation and control problems in elastic robots
Tadikonda, S. S. K.; Baruh, H.
1989-01-01
Computational issues associated with modeling and control of robots with revolute joints and elastic arms are considered. A manipulator with one arm and pinned at one end is considered to investigate various aspects of the modeling procedure and the model, and the effect of coupling between the rigid-body and the elastic motions. The rigid-body motion of a manipulator arm is described by means of a reference frame attached to the shadow beam, and the linear elastic operator denoting flexibility is defined with respect to this reference frame. The small elastic motion assumption coupled with the method of assumed modes is used to model the elasticity in the arm. It is shown that only terms up to quadratic in these model amplitudes need to be retained. An important aspect of the coupling between the rigid-body and the elastic motion is the centrifugal stiffening effect. This effect stiffens the elastic structure, as to be expected on physical grounds, gives rise to a time-varying inertia term for the rigid-body motion, and, in general, results in an effective inertia term smaller than the rigid-body inertia term. Simulation results are presented for an elastic beam pinned at one end and free at the other, and rotating in a horizontal plane, and control issues such as the order of the model, number of sensors, and modal extraction are examined within this context.
Aircraft-on-ground path following control by dynamical adaptive backstepping
Institute of Scientific and Technical Information of China (English)
Chen Bihua; Jiao Zongxia; Shuzhi Sam Ge
2013-01-01
The necessity of improving the air traffic and reducing the aviation emissions drives to investigate automatic steering for aircraft to effectively roll on the ground.This paper addresses the path following control problem of aircraft-on-ground and focuses on the task that the aircraft is required to follow the desired path on the runway by nose wheel automatic steering.The proposed approach is based on dynamical adaptive backstepping so that the system model does not have to be transformed into a canonical triangular form which is necessary in conventional backstepping design.This adaptive controller performs well despite the lack of information on the aerodynamic load and the tire cornering stiffness parameters.Simulation results clearly demonstrate the advantages and effectiveness of the proposed approach.
Cost-Effective Control of Ground-Level Ozone Pollution in and around Beijing
Institute of Scientific and Technical Information of China (English)
Xie Xuxuan; Zhang Shiqiu; Xu Jianhua; Wu Dan; Zhu Tong
2012-01-01
Ground level ozone pollution has become a significant air pollution problem in Beijing. Because of the complex way in which ozone is formed, it is difficult for policy makers to identify optimal control options on a cost-effective basis. This paper identi- fies and assesses a range of options for addressing this problem. We apply the Ambient Least Cost Model and compare the eco- nomic costs of control options, then recommend the most effective sequence to realize pollution control at the lowest cost. The study finds that installing of Stage II gasoline vapor recovery system at Beijing＇s 1446 gasoline stations would be the most cost-effective option. Overall, options to reduce ozone pollution by cutting ve- hicular emissions are much more cost-effective than options to ＂clean up＂ coal-fired power plants.
"Emergence" vs. "Forcing" of Empirical Data? A Crucial Problem of "Grounded Theory" Reconsidered
Directory of Open Access Journals (Sweden)
Udo Kelle
2005-05-01
Full Text Available Since the late 1960s Barney GLASER and Anselm STRAUSS, developers of the methodology of "Grounded Theory" have made several attempts to explicate, clarify and reconceptualise some of the basic tenets of their methodological approach. Diverging concepts and understandings of Grounded Theory have arisen from these attempts which have led to a split between its founders. Much of the explication and reworking of Grounded Theory surrounds the relation between data and theory and the role of previous theoretical assumptions. The book which initially established the popularity of GLASER's and STRAUSS' methodological ideas, "The Discovery of Grounded Theory", contains two conflicting understandings of the relation between data and theory—the concept of "emergence" on the one hand and the concept of "theoretical sensitivity" on the other hand. Much of the later developments of Grounded Theory can be seen as attempts to reconcile these prima facie diverging concepts. Thereby GLASER recommends to draw on a variety of "coding families" while STRAUSS proposes the use of a general theory of action to build an axis for an emerging theory. This paper first summarises the most important developments within "Grounded Theory" concerning the understanding of the relation between empirical data and theoretical statements. Thereby special emphasis will be laid on differences between GLASER's and STRAUSS' concepts and on GLASER's current critique that the concepts of "coding paradigm" and "axial coding" described by STRAUSS and Juliet CORBIN lead to the "forcing" of data. It will be argued that GLASER's critique points out some existing weaknesses of STRAUSS' concepts but vastly exaggerates the risks of the STRAUSSian approach. A main argument of this paper is that basic problems of empirically grounded theory construction can be treated much more effectively if one draws on certain results of contemporary philosophical and epistemological discussions and on widely
De-tabooing dying control - a grounded theory study
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
De-tabooing dying control - a grounded theory study.
Thulesius, Hans O; Scott, Helen; Helgesson, Gert; Lynöe, Niels
2013-03-13
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). 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. 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 or PAS, is seen in Europe and North
Active Thermal Control Experiments for LISA Ground Verification Testing
Higuchi, Sei; DeBra, Daniel B.
2006-11-01
The primary mission goal of LISA is detecting gravitational waves. LISA uses laser metrology to measure the distance between proof masses in three identical spacecrafts. The total acceleration disturbance to each proof mass is required to be below 3 × 10-15 m/s2√Hz . Optical path length variations on each optical bench must be kept below 40 pm/√Hz over 1 Hz to 0.1 mHz. Thermal variations due to, for example, solar radiation or temperature gradients across the proof mass housing will distort the spacecraft causing changes in the mass attraction and sensor location. We have developed a thermal control system developed for the LISA gravitational reference sensor (GRS) ground verification testing which provides thermal stability better than 1 mK/√Hz to f control for the LISA spacecraft to compensate solar irradiation. Thermally stable environment is very demanded for LISA performance verification. In a lab environment specifications can be met with considerable amount of insulation and thermal mass. For spacecraft, the very limited thermal mass calls for an active control system which can meet disturbance rejection and stability requirements simultaneously in the presence of long time delay. A simple proportional plus integral control law presently provides approximately 1 mK/√Hz of thermal stability for over 80 hours. Continuing development of a model predictive feed-forward algorithm will extend performance to below 1 mK/√Hz at f < 1 mHz and lower.
VME-based remote instrument control without ground loops
Belleman, J; González, J L
1997-01-01
New electronics has been developed for the remote control of the pick-up electrodes at the CERN Proton Synchrotron (PS). Communication between VME-based control computers and remote equipment is via full duplex point-to-point digital data links. Data are sent and received in serial format over simple twisted pairs at a rate of 1 Mbit/s, for distances of up to 300 m. Coupling transformers are used to avoid ground loops. The link hardware consists of a general-purpose VME-module, the 'TRX' (transceiver), containing four FIFO-buffered communication channels, and a dedicated control card for each remote station. Remote transceiver electronics is simple enough not to require micro-controllers or processors. Currently, some sixty pick-up stations of various types, all over the PS Complex (accelerators and associated beam transfer lines) are equipped with the new system. Even though the TRX was designed primarily for communication with pick-up electronics, it could also be used for other purposes, for example to for...
Mesh refinement strategy for optimal control problems
Paiva, L. T.; Fontes, F. A. C. C.
2013-10-01
Direct methods are becoming the most used technique to solve nonlinear optimal control problems. Regular time meshes having equidistant spacing are frequently used. However, in some cases these meshes cannot cope accurately with nonlinear behavior. One way to improve the solution is to select a new mesh with a greater number of nodes. Another way, involves adaptive mesh refinement. In this case, the mesh nodes have non equidistant spacing which allow a non uniform nodes collocation. In the method presented in this paper, a time mesh refinement strategy based on the local error is developed. After computing a solution in a coarse mesh, the local error is evaluated, which gives information about the subintervals of time domain where refinement is needed. This procedure is repeated until the local error reaches a user-specified threshold. The technique is applied to solve the car-like vehicle problem aiming minimum consumption. The approach developed in this paper leads to results with greater accuracy and yet with lower overall computational time as compared to using a time meshes having equidistant spacing.
Monaghan, Mark W.; Gillespie, Amanda M.
2013-01-01
During the shuttle era NASA utilized a failure reporting system called the Problem Reporting and Corrective Action (PRACA) it purpose was to identify and track system non-conformance. The PRACA system over the years evolved from a relatively nominal way to identify system problems to a very complex tracking and report generating data base. The PRACA system became the primary method to categorize any and all anomalies from corrosion to catastrophic failure. The systems documented in the PRACA system range from flight hardware to ground or facility support equipment. While the PRACA system is complex, it does possess all the failure modes, times of occurrence, length of system delay, parts repaired or replaced, and corrective action performed. The difficulty is mining the data then to utilize that data in order to estimate component, Line Replaceable Unit (LRU), and system reliability analysis metrics. In this paper, we identify a methodology to categorize qualitative data from the ground system PRACA data base for common ground or facility support equipment. Then utilizing a heuristic developed for review of the PRACA data determine what reports identify a credible failure. These data are the used to determine inter-arrival times to perform an estimation of a metric for repairable component-or LRU reliability. This analysis is used to determine failure modes of the equipment, determine the probability of the component failure mode, and support various quantitative differing techniques for performing repairable system analysis. The result is that an effective and concise estimate of components used in manned space flight operations. The advantage is the components or LRU's are evaluated in the same environment and condition that occurs during the launch process.
Controlling alcohol-related global health problems.
Lam, Tai Hing; Chim, David
2010-07-01
Alcohol's adverse public health impact includes disease, injury, violence, disability, social problems, psychiatric illness, drunk driving, drug use, unsafe sex, and premature death. Furthermore, alcohol is a confirmed human carcinogen. The International Agency for Research on Cancer concluded that alcohol causes cancer of the oral cavity, pharynx, larynx, esophagus, liver, colon-rectum, and breast. World Cancer Research Fund/American Institute for Cancer Research concluded that the evidence justifies recommending avoidance of consuming any alcohol, even in small quantities. Despite being responsible for 3.8% of global deaths (2,255,000 deaths) and 4.6% of global disability-adjusted life years in 2004, alcohol consumption is increasing rapidly in China and Asia. Contrary to the World Health Assembly's call for global control action, Hong Kong has reduced wine and beer taxes to zero since 2008. An International Framework Convention on Alcohol Control is urgently needed. Increasing alcohol taxation and banning alcohol advertisement and promotion are among the most effective policies.
A STABILITY THEOREM FOR CONSTRAINED OPTIMAL CONTROL PROBLEMS
Institute of Scientific and Technical Information of China (English)
M.H. Farag
2004-01-01
This paper presents the stability of difference approximations of an optimal control problem for a quasilinear parabolic equation with controls in the coefficients, boundary conditions and additional restrictions. The optimal control problem has been convered to one of the optimization problem using a penalty function technique. The difference approximations problem for the considered problem is obtained. The estimations of stability of the solution of difference approximations problem are proved. The stability estimation of the solution of difference approximations problem by the controls is obtained.
Control Method of Single-phase Inverter Based Grounding System in Distribution Networks
DEFF Research Database (Denmark)
Wang, Wen; Yan, L.; Zeng, X.
2016-01-01
The asymmetry of the inherent distributed capacitances causes the rise of neutral-to-ground voltage in ungrounded system or high resistance grounded system. Overvoltage may occur in resonant grounded system if Petersen coil is resonant with the distributed capacitances. Thus, the restraint of neu...... of the control method is presented in detail. Experimental results prove the effectiveness and novelty of the proposed grounding system and control method....
Ground control stations for unmanned air vehicles (Review Paper
Directory of Open Access Journals (Sweden)
G. Natarajan
2001-07-01
Full Text Available "During the last five decades, the world has witnessed tremendous growth in the military aircraft technology and the air defence weapons technology. Use of manned aircraft for routine reconnaissance/surveillance missions has become a less preferred option due to possible high attrition rate. Currently, the high political cost of human life has practically earmarked the roles of reconnaissance and surveillance missions to the unmanned air vehicles (UAVs. Almost every major country has a UAV program of its own and this interest has spawned intensive research in the field of UAVs. Presently, the UAVs come in all shapes and sizes, from palm top micro UAVs to giant strategic UAVs that can loiter over targets for extended periods of time. Though UAVs are capable of operating at different levels of autonomy, these are generally controlled from a ground control station (GCS. The GCS is the nerve centre of activity during UAV missions and provides necessary capability to plan and execute UAV missions. The GCS incorporates facilities, such as communication, displays, mission planning and data exploitation. The GCS architecture is highly processor-oriented and hence the computer hardware and software technologies play a major role in the realisation of this vital system. This paper gives an overview of the GCS, its architecture and the current state-of-the-art in various subsystem technologies.
Ground control to major TOM: mitochondria-nucleus communication.
Eisenberg-Bord, Michal; Schuldiner, Maya
2017-01-01
Mitochondria have crucial functions in the cell, including ATP generation, iron-sulfur cluster biogenesis, nucleotide biosynthesis, and amino acid metabolism. All of these functions require tight regulation on mitochondrial activity and homeostasis. As mitochondria biogenesis is controlled by the nucleus and almost all mitochondrial proteins are encoded by nuclear genes, a tight communication network between mitochondria and the nucleus has evolved, which includes signaling cascades, proteins which are dual-localized to the two compartments, and sensing of mitochondrial products by nuclear proteins. All of these enable a crosstalk between mitochondria and the nucleus that allows the 'ground control' to get information on mitochondria's status. Such information facilitates the creation of a cellular balance of mitochondrial status with energetic needs. This communication also allows a transcriptional response in case mitochondrial function is impaired aimed to restore mitochondrial homeostasis. As mitochondrial dysfunction is related to a growing number of genetic diseases as well as neurodegenerative conditions and aging, elucidating the mechanisms governing the mitochondrial/nuclear communication should progress a better understanding of mitochondrial dysfunctions. © 2016 Federation of European Biochemical Societies.
Methodical Grounds of Managing the Product Quality Control
Directory of Open Access Journals (Sweden)
Shapoval Olena A.
2014-01-01
Full Text Available The article analyses the modern state of products quality control management. It justifies a necessity of organisation of the quality control system under conditions of uninterrupted flow line production. It reveals problems connected with a low level of the products quality control management. It forms a set of factors of internal and external environments, which should be taken into account in the process of selection of a type of managerial actions by the products quality control. It considers specific features of identification of the most important factors at an enterprise on the basis of use of the matrix of strategic SWOT analysis. It offers a procedure of identification of a general assessment of factors of influence. It analyses a mechanism of use of main conceptual models, which reflect the system nature of quality management in an organisation – quality pyramids and quality loops. It proves a necessity of application of a principally new scheme of relations between the customer and enterprise, which envisages that requirements of the quality management system focus not on control and screening of semi-finished products, but on creation of conditions that exclude rejects. It considers the role of ISO 9000 in the system of quality management, which recommend the customers to make a preliminary assessment of activity of the producing enterprise.
Ground State Energy of Unitary Fermion Gas with the Thomson Problem Approach
Institute of Scientific and Technical Information of China (English)
CHEN Ji-Sheng
2007-01-01
The dimensionless universal coefficient § defines the ratio of the unitary fermions energy density to that for the ideal non-interacting ones in the non-relativistic limit with T = 0. The classical Thomson problem is taken as a nonperturbative quantum many-body arm to address the ground state energy including the Iow energy nonlinear quantum fluctuation/correlation effects. With the relativistic Dirac continuum field theory formalism, the concise expression for the energy density functional of the strongly interacting limit fermions at both finite temperature and density is obtained. Analytically, the universal factor is calculated to be § = 4/9. The energy gap is △ = 5/18 k2f/(2m).
Evaluation of SAR Data as Source of Ground Control Information: First Results
Vassilaki, D. I.; Ioannidis, C.; Stamos, A. A.
2013-05-01
The high resolution imaging modes of modern SAR sensors has made SAR data compatible with optical images. SAR data offers various capabilities which can enhance the geometric correction process of optical images (accurate, direct and ground-independent georeferencing capabilities and global DEM products). In this paper the first results of an on-going study on the evaluation of SAR data as source of ground control information for the georeferencing of optical images are presented. The georeferencing of optical images using SAR data is in fact a co-registration problem which involves multimodal, mutitemporal, and multiresolution data. And although 2D transformations have proved to be insufficient for the georeferencing process, as they can not account for the distortions due to terrain, quite a few approaches on the registration of optical to SAR data using 2D-2D transformations can still be found in the literature. In this paper the performance of 2D-2D transformations is compared to the 3D-2D projective transformation over a greater area of Earth's surface with arbitrary terrain type. Two alternative forms of ground control information are used: points and FFLFs. The accuracy of the computed results is obtained using independent CPs and it is compared to the geolocation accuracy specification of the optical image, as well as to the accuracy of exhaustive georeferencing done by third parties.
Optimization problems for switched systems with impulsive control
Institute of Scientific and Technical Information of China (English)
Junhao HU; Huayou WANG; Xinzhi LIU; Bin LIU
2005-01-01
By using Impulsive Maximum Principal and three stage optimization method,this paper discusses optimization problems for linear impulsive switched systems with hybrid controls,which includes continuous control and impulsive control.The linear quadratic optimization problems without constraints such as optimal hybrid control,optimal stability and optimal switching instants are addressed in detail.These results are applicable to optimal control problems in economics,mechanics,and management.
Dynamic Programming Method for Impulsive Control Problems
Balkew, Teshome Mogessie
2015-01-01
In many control systems changes in the dynamics occur unexpectedly or are applied by a controller as needed. The time at which a controller implements changes is not necessarily known a priori. For example, many manufacturing systems and flight operations have complicated control systems, and changes in the control systems may be automatically…
Yerlikaya-Özkurt, Fatma; Askan, Aysegul; Weber, Gerhard-Wilhelm
2014-12-01
Ground Motion Prediction Equations (GMPEs) are empirical relationships which are used for determining the peak ground response at a particular distance from an earthquake source. They relate the peak ground responses as a function of earthquake source type, distance from the source, local site conditions where the data are recorded and finally the depth and magnitude of the earthquake. In this article, a new prediction algorithm, called Conic Multivariate Adaptive Regression Splines (CMARS), is employed on an available dataset for deriving a new GMPE. CMARS is based on a special continuous optimization technique, conic quadratic programming. These convex optimization problems are very well-structured, resembling linear programs and, hence, permitting the use of interior point methods. The CMARS method is performed on the strong ground motion database of Turkey. Results are compared with three other GMPEs. CMARS is found to be effective for ground motion prediction purposes.
THE SOLUTION TO THE PROBLEM OF USING GROUND WATER TO COOL LIVESTOCK BUILDINGS
Directory of Open Access Journals (Sweden)
Thay Ngok Shon
2017-01-01
Full Text Available Ambient temperature in the central part of Vietnam in summer can reach 32–35°C; in some places it can be more than 42°C. Hot climate strongly affects the animal organism alongside with the animal weight reduction and reduction the quantity of egg-laying in poultry. Therefore, air conditioning in livestock buildings is necessary. There are several ways to cool the temperature in such buildings, and each one has its own advantages and disadvantages. We propose to use underground water at the temperature of 24–25°C for this purpose. One of the methods of cooling sheds for livestock is sprinkler irrigation of water on the roof. For calculating the amount of heat, removed from the indoor air in the shed to the cooling water, in the first approximation specialists believe in some cases that an appropriate amount of heat being removed is determined mainly by heat transfer from the air inside the shed to the cooling water through the surface of the roof, represented by the lower part of the wave that form the surface of a metal tile, neglecting the influence of heat conduction on top of the wave of the tile surface. Consequentially, such a simplification leads to possible errors. Therefore, the authors solved the problem of cooling shed by irrigation of water on the roof by an analytical method. Specifically, we solved the problem of heat conductivity of the fin of the finite length of constant cross section, wherein different sides of the fin are conjugate with different environments. Additionally, the calculation considered the effect of solar radiation. For this purpose, the authors have created a heat balance equation at steady state for any infinitesimal element of the fin, and solved the differential equation afterwards. The authors applied the results for calculating practical problem of ground water irrigation of a roof of a livestock shed made of metal areas tiles.
Controlling Townsend Ground Squirrels in Beaver County, Utah
Nelson, Mark
2012-01-01
Townsend ground squirrels live in colonies and construct underground burrows that have a number of entrances. The burrows may be up to 6 feet deep. The squirrels generally enter their burrows to aestivate, escaping the late summer heat
Machine Vision Automation for Ground Control Tele-Robotics Project
National Aeronautics and Space Administration — This project seeks to advance ground based tele-robotic capabilities with the development of natural feature target tracking technology with the use of machine...
Dynamic consistency for Stochastic Optimal Control problems
Carpentier, Pierre; Cohen, Guy; De Lara, Michel; Girardeau, Pierre
2010-01-01
For a sequence of dynamic optimization problems, we aim at discussing a notion of consistency over time. This notion can be informally introduced as follows. At the very first time step $t_0$, the decision maker formulates an optimization problem that yields optimal decision rules for all the forthcoming time step $t_0, t_1, ..., T$; at the next time step $t_1$, he is able to formulate a new optimization problem starting at time $t_1$ that yields a new sequence of optimal decision rules. This process can be continued until final time $T$ is reached. A family of optimization problems formulated in this way is said to be time consistent if the optimal strategies obtained when solving the original problem remain optimal for all subsequent problems. The notion of time consistency, well-known in the field of Economics, has been recently introduced in the context of risk measures, notably by Artzner et al. (2007) and studied in the Stochastic Programming framework by Shapiro (2009) and for Markov Decision Processes...
MAIN PROBLEMS OF CONTROLLING OF THE QUALITY
Directory of Open Access Journals (Sweden)
Orlov A. I.
2015-09-01
Full Text Available Controlling of statistical methods to ensure product quality is the special case of controlling organizational and economic methods of management. Today, controlling in the practice of management of Russian companies is understood as "the system of information-analytical and methodological support to achieve their goals." The controller is developing a decision-making rules, the head takes decisions on the basis of these rules. We proved the concept of "controlling of methods". Innovation in management is based, in particular, on the use of new adequate organizational-economic (as well as economicmathematical and statistical methods. Controlling in this area - is the development and application procedures of compliance management used and newly developed (implemented organizationaleconomic methods for the task. Thus, the methodology for controlling is of great practical value in any field in which the actions (operations must be carried out in accordance with certain rules (regulations, standards, guidelines, as in any such area in which we need to use development and application procedures of compliance management used and the newly established (implemented rules for solution of tasks assigned to the organization. In this article, we select a area of controlling as controlling quality, and we discuss its main issues. This is about controlling of organizational-economic methods to ensure product quality, especially about the statistical methods based on probability theory and mathematical statistics. We consider the analysis and synthesis of plans of statistical quality control, optimization options plans of statistical control, truncated plans. Are discussed the differences control plans provider and the consumer, the allocation of units formless (liquid, gas products, the selection of a random sample of the statistical quality control of products, lower estimate of the required sample size. It is established, that is not always necessary
Common Occupational Health Problems In Disease Control In Nigeria
African Journals Online (AJOL)
Common Occupational Health Problems In Disease Control In Nigeria. ... laboratories, hazardous gases like ethylene oxide and nitrous oxides; physical agents like ... When duely exposed, health workers are at high risk of health problems like ...
Take control of font problems in Leopard
Zardetto, Sharon
2009-01-01
Are you suffering from mysterious font problems using Microsoft Office, the Adobe Creative Suite, or other programs in Mac OS X Leopard? Help is at hand, with troubleshooting steps and real-world advice that help you solve problems fast. If you've experienced seemingly inexplicable trouble with characters displaying incorrectly, being unable to type a particular character, fonts missing from Font menus, Font Book crashing, or Character Palette misbehaving, turn to font expert Sharon Zardetto for help. Read this ebook to find the answers to questions such as: Where do fonts belong on my hard
Characterization of the Aerodynamic Ground Effect and Its Influence in Multirotor Control
Directory of Open Access Journals (Sweden)
Pedro Sanchez-Cuevas
2017-01-01
Full Text Available This paper analyzes the ground effect in multirotors, that is, the change in the thrust generated by the rotors when flying close to the ground due to the interaction of the rotor airflow with the ground surface. This effect is well known in single-rotor helicopters but has been assumed erroneously to be similar for multirotors in many cases in the literature. In this paper, the ground effect for multirotors is characterized with experimental tests in several cases and the partial ground effect, a situation in which one or some of the rotors of the multirotor (but not all are under the ground effect, is also characterized. The influence of the different cases of ground effect in multirotor control is then studied with several control approaches in simulation and validated with experiments in a test bench and with outdoor flights.
Design and implementation of a ground control console prototype for OMV
Walcott, Bruce L.
1990-01-01
One of the primary uses of the Flat Floor facility of The Marshall Flight Center is to perform autonomous and teleoperated docking of vehicles similar to NASA's Orbital Maneuvering Vehicle (OMV). Using both the air-bearing vehicle and the 8 DOF Dynamic Overhead Target Simulator (DOTS) in tandem, even the most difficult OMV docking problems can be simulated. The OMV was planned to be flown from the ground by a pilot via teleoperation. Specifications were developed for a prototype Ground Control Console (GCC) from where the vehicle will be flown. In order for testing of the OMV to occur at Flat Floor facility, this GCC must be replicated. The project was divided into three primary tasks: (1) the design and development of the video display; (2) the design and development of the switch panel using the micro switch programmable display pushbutton switches; and (3) the design and development of the hand controllers. A final task is to perform system integration on the results of these three primary tasks.
Controllability Problem of Fractional Neutral Systems: A Survey
Directory of Open Access Journals (Sweden)
Artur Babiarz
2017-01-01
Full Text Available The following article presents recent results of controllability problem of dynamical systems in infinite-dimensional space. Generally speaking, we describe selected controllability problems of fractional order systems, including approximate controllability of fractional impulsive partial neutral integrodifferential inclusions with infinite delay in Hilbert spaces, controllability of nonlinear neutral fractional impulsive differential inclusions in Banach space, controllability for a class of fractional neutral integrodifferential equations with unbounded delay, controllability of neutral fractional functional equations with impulses and infinite delay, and controllability for a class of fractional order neutral evolution control systems.
Optimal control problem for the extended Fisher–Kolmogorov equation
Indian Academy of Sciences (India)
Ning Duan
2016-02-01
In this paper, the optimal control problem for the extended Fisher–Kolmogorov equation is studied. The optimal control under boundary condition is given, the existence of optimal solution to the equation is proved and the optimality system is established.
Feed Forward Neural Network and Optimal Control Problem with Control and State Constraints
Kmet', Tibor; Kmet'ová, Mária
2009-09-01
A feed forward neural network based optimal control synthesis is presented for solving optimal control problems with control and state constraints. The paper extends adaptive critic neural network architecture proposed by [5] to the optimal control problems with control and state constraints. The optimal control problem is transcribed into a nonlinear programming problem which is implemented with adaptive critic neural network. The proposed simulation method is illustrated by the optimal control problem of nitrogen transformation cycle model. Results show that adaptive critic based systematic approach holds promise for obtaining the optimal control with control and state constraints.
Optimal control problems related to the navigation channel engineering
Institute of Scientific and Technical Information of China (English)
朱江; 曾庆存; 郭冬建; 刘卓
1997-01-01
The navigation channel engineering poses optimal control problems of how to find the optimal way of engineering such that the water depth of the channel is maximum under certain budget constraint, or the cost of me en-gineering is minimum while certain goals are achieved. These are typical control problems of distributed system gov erned by hydraulic/sedimentation models. The problems and methods of solutions are discussed Since the models, usually complicated, are nonlinear, they can be solved by solving a series of linear problems For linear problems the solutions are given. Thus the algorithms are simplified.
System and method for transferring telemetry data between a ground station and a control center
Ray, Timothy J. (Inventor); Ly, Vuong T. (Inventor)
2012-01-01
Disclosed herein are systems, computer-implemented methods, and tangible computer-readable media for coordinating communications between a ground station, a control center, and a spacecraft. The method receives a call to a simple, unified application programmer interface implementing communications protocols related to outer space, when instruction relates to receiving a command at the control center for the ground station generate an abstract message by agreeing upon a format for each type of abstract message with the ground station and using a set of message definitions to configure the command in the agreed upon format, encode the abstract message to generate an encoded message, and transfer the encoded message to the ground station, and perform similar actions when the instruction relates to receiving a second command as a second encoded message at the ground station from the control center and when the determined instruction type relates to transmitting information to the control center.
Bakir, Ali; Bakir, Vian
2006-01-01
In this paper we critique grounded theory's ability to fulfil its aim of offering a practical vehicle for prediction, change, and control as stipulated in grounded theory's original formulation by Glaser and Strauss, and later developed by Strauss. We do this through a case study approach, whereby we develop a grounded theory of leisure and…
Eurobot Ground Prototype Control System Overview & Tests Results
Merlo, Andrea; Martelli, Andrea; Pensavalle, Emanuele; Ferraris, Simona; Didot, Frederic
2010-08-01
In the planned missions on Moon and Mars, robotics can play a key role, as robots can both assist astronauts and, above all, relieve them of dangerous or too difficult tasks. To this aim, both cooperative capabilities and a great level of autonomy are needed: the robotic crew assistant must be able to work on its own, without supervision by humans, and to help astronauts to accomplish tasks otherwise unfeasible for them. Within this context, a project named Eurobot Ground Prototype, conducted in conjunction with ESA and Thales Alenia Space, is presented. EGP is a dual-arm mobile manipulator and exploits both stereo cameras and force/torque sensors in order to rely on visual and force feedback. This paper provides an overview of the performed and on going activities within the Eurobot Ground Prototype project.
Refinement from a control problem to program
DEFF Research Database (Denmark)
Schenke, Michael; Ravn, Anders P.
1996-01-01
for a control task, exemplified by a steam boiler.The same formalism is used to refine requirements to a functional design.Through a suitable transformation this is taken to an event andaction based formalism. Finally components in this design for a distributedarchitecture are transformed to occam-like programs....
A weak Hamiltonian finite element method for optimal control problems
Hodges, Dewey H.; Bless, Robert R.
1990-01-01
A temporal finite element method based on a mixed form of the Hamiltonian weak principle is developed for dynamics and optimal control problems. The mixed form of Hamilton's weak principle contains both displacements and momenta as primary variables that are expanded in terms of nodal values and simple polynomial shape functions. Unlike other forms of Hamilton's principle, however, time derivatives of the momenta and displacements do not appear therein; instead, only the virtual momenta and virtual displacements are differentiated with respect to time. Based on the duality that is observed to exist between the mixed form of Hamilton's weak principle and variational principles governing classical optimal control problems, a temporal finite element formulation of the latter can be developed in a rather straightforward manner. Several well-known problems in dynamics and optimal control are illustrated. The example dynamics problem involves a time-marching problem. As optimal control examples, elementary trajectory optimization problems are treated.
Weak Hamiltonian finite element method for optimal control problems
Hodges, Dewey H.; Bless, Robert R.
1991-01-01
A temporal finite element method based on a mixed form of the Hamiltonian weak principle is developed for dynamics and optimal control problems. The mixed form of Hamilton's weak principle contains both displacements and momenta as primary variables that are expanded in terms of nodal values and simple polynomial shape functions. Unlike other forms of Hamilton's principle, however, time derivatives of the momenta and displacements do not appear therein; instead, only the virtual momenta and virtual displacements are differentiated with respect to time. Based on the duality that is observed to exist between the mixed form of Hamilton's weak principle and variational principles governing classical optimal control problems, a temporal finite element formulation of the latter can be developed in a rather straightforward manner. Several well-known problems in dynamics and optimal control are illustrated. The example dynamics problem involves a time-marching problem. As optimal control examples, elementary trajectory optimization problems are treated.
On a Highly Nonlinear Self-Obstacle Optimal Control Problem
Energy Technology Data Exchange (ETDEWEB)
Di Donato, Daniela, E-mail: daniela.didonato@unitn.it [University of Trento, Department of Mathematics (Italy); Mugnai, Dimitri, E-mail: dimitri.mugnai@unipg.it [Università di Perugia, Dipartimento di Matematica e Informatica (Italy)
2015-10-15
We consider a non-quadratic optimal control problem associated to a nonlinear elliptic variational inequality, where the obstacle is the control itself. We show that, fixed a desired profile, there exists an optimal solution which is not far from it. Detailed characterizations of the optimal solution are given, also in terms of approximating problems.
Study of optimal control problems for hybrid dynamical systems
Institute of Scientific and Technical Information of China (English)
Gao Rui; Wang Lei; Wang Yuzhen
2006-01-01
From the viewpoint of continuous systems, optimal control problem is proposed for a class of controlled Hybrid dynamical systems. Then a mathematical method- HDS minimum principle is put forward, which can solve the above problem. The HDS minimum principle is proved by means of Ekeland's variational principle.
A Summary of Some Discrete-Event System Control Problems
Rudie, Karen
A summary of the area of control of discrete-event systems is given. In this research area, automata and formal language theory is used as a tool to model physical problems that arise in technological and industrial systems. The key ingredients to discrete-event control problems are a process that can be modeled by an automaton, events in that process that cannot be disabled or prevented from occurring, and a controlling agent that manipulates the events that can be disabled to guarantee that the process under control either generates all the strings in some prescribed language or as many strings as possible in some prescribed language. When multiple controlling agents act on a process, decentralized control problems arise. In decentralized discrete-event systems, it is presumed that the agents effecting control cannot each see all event occurrences. Partial observation leads to some problems that cannot be solved in polynomial time and some others that are not even decidable.
Locally controlled globally smooth ground surface reconstruction from terrestrial point clouds
Rychkov, Igor
2012-01-01
Approaches to ground surface reconstruction from massive terrestrial point clouds are presented. Using a set of local least squares (LSQR) planes, the "holes" are filled either from the ground model of the next coarser level or by Hermite Radial Basis Functions (HRBF). Global curvature continuous as well as infinitely smooth ground surface models are obtained with Partition of Unity (PU) using either tensor product B-Splines or compactly supported exponential function. The resulting surface function has local control enabling fast evaluation.
Complex collaborative problem-solving processes in mission control.
Fiore, Stephen M; Wiltshire, Travis J; Oglesby, James M; O'Keefe, William S; Salas, Eduardo
2014-04-01
NASA's Mission Control Center (MCC) is responsible for control of the International Space Station (ISS), which includes responding to problems that obstruct the functioning of the ISS and that may pose a threat to the health and well-being of the flight crew. These problems are often complex, requiring individuals, teams, and multiteam systems, to work collaboratively. Research is warranted to examine individual and collaborative problem-solving processes in this context. Specifically, focus is placed on how Mission Control personnel-each with their own skills and responsibilities-exchange information to gain a shared understanding of the problem. The Macrocognition in Teams Model describes the processes that individuals and teams undertake in order to solve problems and may be applicable to Mission Control teams. Semistructured interviews centering on a recent complex problem were conducted with seven MCC professionals. In order to assess collaborative problem-solving processes in MCC with those predicted by the Macrocognition in Teams Model, a coding scheme was developed to analyze the interview transcriptions. Findings are supported with excerpts from participant transcriptions and suggest that team knowledge-building processes accounted for approximately 50% of all coded data and are essential for successful collaborative problem solving in mission control. Support for the internalized and externalized team knowledge was also found (19% and 20%, respectively). The Macrocognition in Teams Model was shown to be a useful depiction of collaborative problem solving in mission control and further research with this as a guiding framework is warranted.
Control and Alcohol-Problem Recognition among College Students
Simons, Raluca M.; Hahn, Austin M.; Simons, Jeffrey S.; Gaster, Sam
2015-01-01
Objective: This study examined negative control (ie, perceived lack of control over life outcomes) and need for control as predictors of alcohol-problem recognition, evaluations (good/bad), and expectancies (likely/unlikely) among college students. The study also explored the interaction between the need for control and alcohol consumption in…
Ha, S. H.; Choi, S. B.; Lee, G. S.; Yoo, W. H.
2013-02-01
This paper presents control performance evaluation of railway vehicle featured by semi-active suspension system using magnetorheological (MR) fluid damper. In order to achieve this goal, a nine degree of freedom of railway vehicle model, which includes car body and bogie, is established. The wheel-set data is loaded from measured value of railway vehicle. The MR damper system is incorporated with the governing equation of motion of the railway vehicle model which includes secondary suspension. To illustrate the effectiveness of the controlled MR dampers on suspension system of railway vehicle, the control law using the sky-ground hook controller is adopted. This controller takes into account for both vibration control of car body and increasing stability of bogie by adopting a weighting parameter between two performance requirements. The parameters appropriately determined by employing a fuzzy algorithm associated with two fuzzy variables: the lateral speed of the car body and the lateral performance of the bogie. Computer simulation results of control performances such as vibration control and stability analysis are presented in time and frequency domains.
Numerical methods for solving terminal optimal control problems
Gornov, A. Yu.; Tyatyushkin, A. I.; Finkelstein, E. A.
2016-02-01
Numerical methods for solving optimal control problems with equality constraints at the right end of the trajectory are discussed. Algorithms for optimal control search are proposed that are based on the multimethod technique for finding an approximate solution of prescribed accuracy that satisfies terminal conditions. High accuracy is achieved by applying a second-order method analogous to Newton's method or Bellman's quasilinearization method. In the solution of problems with direct control constraints, the variation of the control is computed using a finite-dimensional approximation of an auxiliary problem, which is solved by applying linear programming methods.
Using MODFLOW 2000 to model ET and recharge for shallow ground water problems.
Doble, Rebecca C; Simmons, Craig T; Walker, Glen R
2009-01-01
In environments with shallow ground water elevation, small changes in the water table can cause significant variations in recharge and evapotranspiration fluxes. Particularly, where ground water is close to the soil surface, both recharge and evapotranspiration are regulated by a thin unsaturated zone and, for accuracy, must be represented using nonconstant and often nonlinear relationships. The most commonly used ground water flow model today, MODFLOW, was originally designed with a modular structure with independent packages representing recharge and evaporation processes. Systems with shallow ground water, however, may be better represented using either a recharge function that varies with ground water depth or a continuous recharge and evapotranspiration function that is dependent on depth to water table. In situations where the boundaries between recharging and nonrecharging cells change with time, such as near a seepage zone, a continuous ground water flux relationship allows recharge rates to change with depth rather than having to calculate them at each stress period. This research article describes the modification of the MODFLOW 2000 recharge and segmented evapotranspiration packages into a continuous recharge-discharge function that allows ground water flux to be represented as a continuous process, dependent on head. The modifications were then used to model long-term recharge and evapotranspiration processes on a saline, semiarid floodplain in order to understand spatial patterns of salinization, and an overview of this process is given.
Controlled ecological life support system - biological problems
Moore, B., III (Editor); Macelroy, R. D. (Editor)
1982-01-01
The general processes and controls associated with two distinct experimental paradigms are examined. Specific areas for research related to biotic production (food production) and biotic decomposition (waste management) are explored. The workshop discussions were directed toward Elemental cycles and the biological factors that affect the transformations of nutrients into food, of food material into waste, and of waste into nutrients were discussed. To focus on biological issues, the discussion assumed that (1) food production would be by biological means (thus excluding chemical synthesis), (2) energy would not be a limiting factor, and (3) engineering capacity for composition and leak rate would be adequate.
A knowledge base system for ground control over abandoned mines
Energy Technology Data Exchange (ETDEWEB)
Nazimko, V.V.; Zviagilsky, E.L. [Donetsk State Technical University, Donetsk (Ukraine)
1999-07-01
The knowledge of engineering systems has been developed to choose optimal technology for subsidence prevention over abandoned mines. The expert system treats a specific case, maps consequences of actions and derives relevant technology (or a set of technologies) that should be used to prevent ground subsidence. Input parameters that characterise the case are treated using fuzzy logic and are then fed to a neural network. The network has been successfully trained by a backpropagation algorithm on the basis of three fuzzy rules. 5 refs., 2 figs., 3 tabs.
Chen, G.; Wang, L. L.
Taking green demonstration center building air conditioning system as an example, this paper presents the temperature and humidity independent control system combined with ground source heat pump system, emphasis on the design of dry terminal device system, fresh air system and ground source heat pump system.
DEFF Research Database (Denmark)
Watanabe, Tatsuya; Matsuoka, Norikazu; Christiansen, Hanne Hvidtfeldt
2017-01-01
This study examines soil physical and environmental conditions controlling patterned-ground variability on an alluvial fan in a continuous permafrost landscape, at Adventdalen, Svalbard. On-site monitoring of ground temperature, soil moisture and snow depth, laboratory analyses of soil physical...
Distributed pheromone-based swarming control of unmanned air and ground vehicles for RSTA
Sauter, John A.; Mathews, Robert S.; Yinger, Andrew; Robinson, Joshua S.; Moody, John; Riddle, Stephanie
2008-04-01
The use of unmanned vehicles in Reconnaissance, Surveillance, and Target Acquisition (RSTA) applications has received considerable attention recently. Cooperating land and air vehicles can support multiple sensor modalities providing pervasive and ubiquitous broad area sensor coverage. However coordination of multiple air and land vehicles serving different mission objectives in a dynamic and complex environment is a challenging problem. Swarm intelligence algorithms, inspired by the mechanisms used in natural systems to coordinate the activities of many entities provide a promising alternative to traditional command and control approaches. This paper describes recent advances in a fully distributed digital pheromone algorithm that has demonstrated its effectiveness in managing the complexity of swarming unmanned systems. The results of a recent demonstration at NASA's Wallops Island of multiple Aerosonde Unmanned Air Vehicles (UAVs) and Pioneer Unmanned Ground Vehicles (UGVs) cooperating in a coordinated RSTA application are discussed. The vehicles were autonomously controlled by the onboard digital pheromone responding to the needs of the automatic target recognition algorithms. UAVs and UGVs controlled by the same pheromone algorithm self-organized to perform total area surveillance, automatic target detection, sensor cueing, and automatic target recognition with no central processing or control and minimal operator input. Complete autonomy adds several safety and fault tolerance requirements which were integrated into the basic pheromone framework. The adaptive algorithms demonstrated the ability to handle some unplanned hardware failures during the demonstration without any human intervention. The paper describes lessons learned and the next steps for this promising technology.
A framework for the natural-language-perception-based creative control of unmanned ground vehicles
Ghaffari, Masoud; Liao, Xiaoqun; Hall, Ernest L.
2004-09-01
Mobile robots must often operate in an unstructured environment cluttered with obstacles and with many possible action paths. That is why mobile robotics problems are complex with many unanswered questions. To reach a high degree of autonomous operation, a new level of learning is required. On the one hand, promising learning theories such as the adaptive critic and creative control have been proposed, while on other hand the human brain"s processing ability has amazed and inspired researchers in the area of Unmanned Ground Vehicles but has been difficult to emulate in practice. A new direction in the fuzzy theory tries to develop a theory to deal with the perceptions conveyed by the natural language. This paper tries to combine these two fields and present a framework for autonomous robot navigation. The proposed creative controller like the adaptive critic controller has information stored in a dynamic database (DB), plus a dynamic task control center (TCC) that functions as a command center to decompose tasks into sub-tasks with different dynamic models and multi-criteria functions. The TCC module utilizes computational theory of perceptions to deal with the high levels of task planning. The authors are currently trying to implement the model on a real mobile robot and the preliminary results have been described in this paper.
Adaptive Mixed Finite Element Methods for Parabolic Optimal Control Problems
Zuliang Lu
2011-01-01
We will investigate the adaptive mixed finite element methods for parabolic optimal control problems. The state and the costate are approximated by the lowest-order Raviart-Thomas mixed finite element spaces, and the control is approximated by piecewise constant elements. We derive a posteriori error estimates of the mixed finite element solutions for optimal control problems. Such a posteriori error estimates can be used to construct more efficient and reliable adaptive mixed finite element ...
Turnpike theory of continuous-time linear optimal control problems
Zaslavski, Alexander J
2015-01-01
Individual turnpike results are of great interest due to their numerous applications in engineering and in economic theory; in this book the study is focused on new results of turnpike phenomenon in linear optimal control problems. The book is intended for engineers as well as for mathematicians interested in the calculus of variations, optimal control, and in applied functional analysis. Two large classes of problems are studied in more depth. The first class studied in Chapter 2 consists of linear control problems with periodic nonsmooth convex integrands. Chapters 3-5 consist of linear control problems with autonomous nonconvex and nonsmooth integrands. Chapter 6 discusses a turnpike property for dynamic zero-sum games with linear constraints. Chapter 7 examines genericity results. In Chapter 8, the description of structure of variational problems with extended-valued integrands is obtained. Chapter 9 ends the exposition with a study of turnpike phenomenon for dynamic games with extended value integran...
Danielová, M.; Hummel, P.
2016-06-01
The need for rapid deployment of aerial and satellite imagery in support of GIS and engineering integration projects require new sources of geodetic control to ensure the accuracy for geospatial projects. In the past, teams of surveyors would need to deploy to project areas to provide targeted or photo identifiable points that are used to provide data for orthorecificaion, QA/QC and calibration for multi-platform sensors. The challenge of integrating street view, UAS, airborne and Space based sensors to produce the common operational picture requires control to tie multiple sources together. Today commercial off the shelf delivery of existing photo identifiable control is increasing the speed of deployment of this data without having to revisit sites over and over again. The presentation will discuss the processes developed by CompassData to build a global library of 40,000 control points available today. International Organization for Standardization (ISO) based processes and initiatives ensure consistent quality of survey data, photo identifiable features selected and meta data to support photogrammetrist, engineers and GIS professionals to quickly deliver projects with better accuracy.
Lazarus, E.
2015-12-01
In the archetypal "tragedy of the commons" narrative, local farmers pasture their cows on the town common. Soon the common becomes crowded with cows, who graze it bare, and the arrangement of open access to a shared resource ultimately fails. The "tragedy" involves social and physical processes, but the denouement depends on who is telling the story. An economist might argue that the system collapses because each farmer always has a rational incentive to graze one more cow. An ecologist might remark that the rate of grass growth is an inherent control on the common's carrying capacity. And a geomorphologist might point out that processes of soil degradation almost always outstrip processes of soil production. Interdisciplinary research into human-environmental systems still tends to favor disciplinary vantages. In the context of Anthropocene grand challenges - including fundamental insight into dynamics of landscape resilience, and what the dominance of human activities means for processes of change and evolution on the Earth's surface - two disciplines in particular have more to talk about than they might think. Here, I use three examples - (1) beach nourishment, (2) upstream/downstream fluvial asymmetry, and (3) current and historical "land grabbing" - to illustrate a range of interconnections between physical Earth-surface science and common-pool resource economics. In many systems, decision-making and social complexity exert stronger controls on landscape expression than do physical geomorphological processes. Conversely, human-environmental research keeps encountering multi-scale, emergent problems of resource use made 'common-pool' by water, nutrient and sediment transport dynamics. Just as Earth-surface research can benefit from decades of work on common-pool resource systems, quantitative Earth-surface science can make essential contributions to efforts addressing complex problems in environmental sustainability.
The In-Transit Vigilant Covering Tour Problem of Routing Unmanned Ground Vehicles
2012-08-01
15 Figure 2. A classic VRP ...17 Figure 3. Solution for a VRP ........................................................................................18 Figure 4. Solution...of NP-hard problems, such as the Traveling Salesman Problem (TSP), Vehicle Routing Problem ( VRP ), and Covering Salesman Problem (CSP) etc. We will
Hierarchical control based on Hopfield network for nonseparable optimization problems
Institute of Scientific and Technical Information of China (English)
无
2005-01-01
The nonseparable optimization control problem is considered, where the overall objective function is not of an additive form with respect to subsystems. Since there exists the problem that computation is very slow when using iterative algorithms in multiobjective optimization, Hopfield optimization hierarchical network based on IPM is presented to overcome such slow computation difficulty. Asymptotic stability of this Hopfield network is proved and its equilibrium point is the optimal point of the original problem. The simulation shows that the net is effective to deal with the optimization control problem for large-scale nonseparable steady state systems.
Ground Control for Non-Emplacement Drifts for LA
Energy Technology Data Exchange (ETDEWEB)
D. Tang
2004-02-26
The purpose of this calculation is to analyze the stability of repository non-emplacement drifts during the preclosure period, and to provide a final ground support method for non-emplacement drifts for the License Application (LA). This calculation will provide input for the development of LA documents. The scope of this calculation is limited to the non-emplacement drifts including access mains, ramps, exhaust mains, turnouts, intersections between access mains and turnouts, and intersections between exhaust mains and emplacement drifts, portals, TBM launch chambers, observation drift and test alcove in the performance confirmation (PC) facilities, etc. The calculation is limited to the non-emplacement drifts subjected to a combined loading of in-situ stress, seismic stress, and/or thermal stress. Other effects such as hydrological and chemical effects are not considered in this analysis.
Road-Following Formation Control of Autonomous Ground Vehicles
Ono, Masahiro; Droge, Greg; Grip, Havard; Toupet, Olivier; Scrapper, Chris; Rahmani, Amir
2015-01-01
This work presents a novel cooperative path planning for formation keeping robots traversing along a road with obstacles and possible narrow passages. A unique challenge in this problem is a requirement for spatial and temporal coordination between vehicles while ensuring collision and obstacle avoidance.
A transformation method for stochastic control problems with partial observations
Koole, G.M.
1996-01-01
Two stochastic control problems with partial observations are studied, o ne where the policy or control law depends only on the latest observation (the controller does not have recall of observations), and the other with the standard partial observations model. The equivalent full observation probl
Optimal Control Problems for Nonlinear Variational Evolution Inequalities
Directory of Open Access Journals (Sweden)
Eun-Young Ju
2013-01-01
Full Text Available We deal with optimal control problems governed by semilinear parabolic type equations and in particular described by variational inequalities. We will also characterize the optimal controls by giving necessary conditions for optimality by proving the Gâteaux differentiability of solution mapping on control variables.
Numerical solution of control problems governed by nonlinear differential equations
Energy Technology Data Exchange (ETDEWEB)
Heinkenschloss, M. [Virginia Polytechnic Institute and State Univ., Blacksburg, VA (United States)
1994-12-31
In this presentation the author investigates an iterative method for the solution of optimal control problems. These problems are formulated as constrained optimization problems with constraints arising from the state equation and in the form of bound constraints on the control. The method for the solution of these problems uses the special structure of the problem arising from the bound constraint and the state equation. It is derived from SQP methods and projected Newton methods and combines the advantages of both methods. The bound constraint is satisfied by all iterates using a projection, the nonlinear state equation is satisfied in the limit. Only a linearized state equation has to be solved in every iteration. The solution of the linearized problems are done using multilevel methods and GMRES.
A General Theory of Markovian Time Inconsistent Stochastic Control Problems
DEFF Research Database (Denmark)
Björk, Tomas; Murgochi, Agatha
We develop a theory for stochastic control problems which, in various ways, are time inconsistent in the sense that they do not admit a Bellman optimality principle. We attach these problems by viewing them within a game theoretic framework, and we look for Nash subgame perfect equilibrium points...... examples of time inconsistency in the literature are easily seen to be special cases of the present theory. We also prove that for every time inconsistent problem, there exists an associated time consistent problem such that the optimal control and the optimal value function for the consistent problem....... For a general controlled Markov process and a fairly general objective functional we derive an extension of the standard Hamilton-Jacobi-Bellman equation, in the form of a system of on-linear equations, for the determination for the equilibrium strategy as well as the equilibrium value function. All known...
Ground Handling Business at Non-European Biggest World Airports as a Problem of Market Structures
Directory of Open Access Journals (Sweden)
Anna Tomová
2015-12-01
Full Text Available In the paper we analyse the market structures of ground handling at the biggest non-European passenger and cargo airports in accordance with the ACI list of the most important world airports in 2014. Using the IATA IGHC database as of spring 2015, our analysis revealed that out of Europe double digit numbers of providers are rare what contrasts with situation in Europe where ground handling markets were deregulated by the Council Directive 96/67/EC. The analysis also brought that the monopolistic structures of ground handling markets were more specific for the regions of Asia and the Middle East. Airports as ground handling providers were not found within the analysed sample in North America, Latin America, Africa and Australia and Oceania, while this arrangement was to a larger extent present at the analysed Asian airports. Asia and the Middle East biggest airports are identified by us as candidates for further deregulation of ground handling arguing by forecasted demand for air services in the regions, although expected deregulation may be curbed by national regulators.
Control of heat source in a heat conduction problem
Lyashenko, V.; Kobilskaya, E.
2014-11-01
The mathematical model of thermal processes during the heat treatment of a moving axisymmetric environment, for example wire. is considered. The wire is heated by internal constantly or periodically operating heat source. It is presented in the form of initial-boundary value problem for the unsteady heat equation with internal constantly or periodically operating heat source. The purpose of the work is the definition of control parameter of temperature field of a moving area, which is heated by internal heat source. The control parameters are determined by solving a nonlocal problem for the heat equation. The problem of getting an adequate temperature distribution throughout the heating area is considered. Therefore, a problem of heat source control is solved, in particular, control by electric current. Control of the heat source allows to maintain the necessary, from a technological point of view, temperature in the heating area. In this paper, to find additional information about the source of heat. The integral condition is used in the control problem. Integral condition, which is considered in the work, determines the energy balance of the heating zone and connects the desired temperature distribution in the internal points of area with temperatures at the boundaries. Control quality in an extremum formulation of the problem is assessed using the quadratic functional. In function space, from a physical point of view, proposed functional is the absolute difference between the actual emission of energy and absorbed energy in the heating zone. The absorbed energy is calculated by solving of the boundary value problem. Methods of determining the control parameters of temperature field are proposed. The resulting problem is solved by iterative methods. At different physical conditions, numerical calculations are carried out, control parameters of the heat treatment process are obtained.
Higher-order techniques for some problems of nonlinear control
Directory of Open Access Journals (Sweden)
Sarychev Andrey V.
2002-01-01
Full Text Available A natural first step when dealing with a nonlinear problem is an application of some version of linearization principle. This includes the well known linearization principles for controllability, observability and stability and also first-order optimality conditions such as Lagrange multipliers rule or Pontryagin's maximum principle. In many interesting and important problems of nonlinear control the linearization principle fails to provide a solution. In the present paper we provide some examples of how higher-order methods of differential geometric control theory can be used for the study nonlinear control systems in such cases. The presentation includes: nonlinear systems with impulsive and distribution-like inputs; second-order optimality conditions for bang–bang extremals of optimal control problems; methods of high-order averaging for studying stability and stabilization of time-variant control systems.
Lossless Convexification of Control Constraints for a Class of Nonlinear Optimal Control Problems
Blackmore, Lars; Acikmese, Behcet; Carson, John M.,III
2012-01-01
In this paper we consider a class of optimal control problems that have continuous-time nonlinear dynamics and nonconvex control constraints. We propose a convex relaxation of the nonconvex control constraints, and prove that the optimal solution to the relaxed problem is the globally optimal solution to the original problem with nonconvex control constraints. This lossless convexification enables a computationally simpler problem to be solved instead of the original problem. We demonstrate the approach in simulation with a planetary soft landing problem involving a nonlinear gravity field.
Science of empirical design in mining ground control
Institute of Scientific and Technical Information of China (English)
Mark Christopher
2016-01-01
Many problems in rock engineering are limited by our imperfect knowledge of the material properties and failure mechanics of rock masses. Mining problems are somewhat unique, however, in that plenty of real world experience is generally available and can be turned into valuable experimental data. Every pillar that is developed, or stope that is mined, represents a full-scale test of a rock mechanics design. By harvesting these data, and then using the appropriate statistical techniques to interpret them, mining engineers have developed powerful design techniques that are widely used around the world. Successful empirical methods are readily accepted because they are simple, transparent, practical, and firmly tethered to reality. The author has been intimately associated with empirical design for his entire career, but his previous publications have described the application of individual techniques to specific problems. The focus of this paper is the process used to develop a successful empirical method. A six-stage process is described:identification of the problem, and of the end users of the final product;devel-opment of a conceptual rock mechanics model, and identification of the key parameters in that model;identification of measures for each of the key parameters, and the development of new measures (such as rating scales) where necessary;data sources and data collection;statistical analysis;and packaging of the final product. Each of these stages has its own potential rewards and pitfalls, which will be illustrated by incidents from the author’s own experience. The ultimate goal of this paper is to provide a new and deeper appreciation for empirical techniques, as well as some guidelines and opportunities for future developers.
Schoenfeld's problem solving theory in a student controlled learning environment
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
Efficient differential evolution algorithms for multimodal optmal control problems
Lopez Cruz, I.L.; Willigenburg, van L.G.; Straten, van G.
2003-01-01
Many methods for solving optimal control problems, whether direct or indirect, rely upon gradient information and therefore may converge to a local optimum. Global optimisation methods like Evolutionary algorithms, overcome this problem. In this work it is investigated how well novel and easy to und
Schoenfeld's problem solving theory in a student controlled learning environment
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
Constraint Algorithm for Extremals in Optimal Control Problems
Barbero-Linan, Maria
2007-01-01
A characterization of different kinds of extremals of optimal control problems is given if we take an open control set. A well known constraint algorithm for implicit differential equations is adapted to the study of such problems. Some necessary conditions of Pontryagin's Maximum Principle determine the primary constraint submanifold for the algorithm. Some examples in the control literature, such as subRiemannian geometry and control-affine systems, are revisited to give, in a clear geometric way, a subset where the abnormal, normal and strict abnormal extremals stand.
Control problems of discrete-time dynamical systems
Hasegawa, Yasumichi
2013-01-01
This monograph deals with control problems of discrete-time dynamical systems which include linear and nonlinear input/output relations. It will be of popular interest to researchers, engineers and graduate students who specialized in system theory. A new method which produces manipulated inputs is presented in the sense of state control and output control. This monograph provides new results and their extensions which can also be more applicable for nonlinear dynamical systems. To present the effectiveness of the method, many numerical examples of control problems are provided as well.
Adaptive Swarm Formation Control for Hybrid Ground and Aerial Assets
Barnes, Laura; Garcia, Richard; Fields, Mary Anne; Valavanis, Kimon
2010-01-01
In this work, a methodology for control and coordination of UAVs and UGVs has been presented. UAVs and UGVs were integrated into a single team and were able to adapt their formation accordingly. Potential field functions together with limiting functions can be successfully utilized to control UGV and UAV swarm formation, obstacle avoidance and the overall swarm movement. A single UAV was also successfully used to pull the UGV swarm into formation. These formations can move as a un...
Problems and possibilities of astronauts—Ground communication content analysis validity check
Kanas, Nick; Gushin, Vadim; Yusupova, Anna
The analysis of space crew's communication with mission control (MC) is the standard operational procedure of the psychological support group in the Institute for Biomedical problems, Russia. For more than 20 years it is used for the monitoring of the behavioral health of Russian crewmembers in space. We apply quantitative speech content analysis to reveal relationship dynamics within the group and between the crew and MC. We suggest that the features of individual communicative style reflect psychological emotional status and individuality of communicator, his coping strategy, fixed by POMS. Moreover, the appearance of certain psychological complexities would become apparent both in POMS profile change and in communicative style change. As a result of the validity check we arrived to a new objective method of crews' dynamic psychological monitoring. This method would not take any of astronauts' time, would not need any on-board equipment, and at the same time it is based on real performance in space, i.e. astronauts communication with MC.
STOCHASTIC LINEAR QUADRATIC OPTIMAL CONTROL PROBLEMS WITH RANDOM COEFFICIENTS
Institute of Scientific and Technical Information of China (English)
无
2000-01-01
This paper studies a stochastic linear quadratic optimal control problem (LQ problem, for short), for which the coefficients are allowed to be random and the cost functional is allowed to have a negative weight on the square of the control variable. The authors introduce the stochastic Riccati equation for the LQ problem. This is a backward SDE with a complicated nonlinearity and a singularity. The local solvability of such a backward SDE is established, which by no means is obvious. For the case of deterministic coefficients, some further discussions on the Riccati equations have been carried out. Finally, an illustrative example is presented.
Chebyshev-Legendre method for discretizing optimal control problems
Institute of Scientific and Technical Information of China (English)
ZHANG Wen; MA He-ping
2009-01-01
In this paper, a numerical method for solving the optimal control (OC) problems is presented. The method is enlightened by the Chebyshev-Legendre (CL) method for solving the partial differential equations (PDEs). The Legen-dre expansions are used to approximate both the control and the state functions. The constraints are discretized over the Chebyshev-Gauss-Lobatto (CGL) collocation points. A Legendre technique is used to approximate the integral involved in the performance index. The OC problem is changed into an equivalent nonlinear programming problem which is directly solved. The fast Legendre transform is employed to reduce the computation time. Several further illustrative examples demonstrate the efficiency of the proposed method.
On the optimal control problem for two regions’ macroeconomic model
Directory of Open Access Journals (Sweden)
Surkov Platon G.
2015-12-01
Full Text Available In this paper we consider a model of joint economic growth of two regions. This model bases on the classical Kobb-Douglas function and is described by a nonlinear system of differential equations. The interaction between regions is carried out by changing the balance of trade. The optimal control problem for this system is posed and the Pontryagin maximum principle is used for analysis the problem. The maximized functional represents the global welfare of regions. The numeric solution of the optimal control problem for particular regions is found. The used parameters was obtained from the basic scenario of the MERGE
Yazidi, Anis; Oommen, B John; Goodwin, Morten
2016-04-28
The purpose of this paper is to propose a solution to an extremely pertinent problem, namely, that of identifying unreliable sensors (in a domain of reliable and unreliable ones) without any knowledge of the ground truth. This fascinating paradox can be formulated in simple terms as trying to identify stochastic liars without any additional information about the truth. Though apparently impossible, we will show that it is feasible to solve the problem, a claim that is counter-intuitive in and of itself. One aspect of our contribution is to show how redundancy can be introduced, and how it can be effectively utilized in resolving this paradox. Legacy work and the reported literature (for example, in the so-called weighted majority algorithm) have merely addressed assessing the reliability of a sensor by comparing its reading to the ground truth either in an online or an offline manner. Unfortunately, the fundamental assumption of revealing the ground truth cannot be always guaranteed (or even expected) in many real life scenarios. While some extensions of the Condorcet jury theorem [9] can lead to a probabilistic guarantee on the quality of the fused process, they do not provide a solution to the unreliable sensor identification problem. The essence of our approach involves studying the agreement of each sensor with the rest of the sensors, and not comparing the reading of the individual sensors with the ground truth-as advocated in the literature. Under some mild conditions on the reliability of the sensors, we can prove that we can, indeed, filter out the unreliable ones. Our approach leverages the power of the theory of learning automata (LA) so as to gradually learn the identity of the reliable and unreliable sensors. To achieve this, we resort to a team of LA, where a distinct automaton is associated with each sensor. The solution provided here has been subjected to rigorous experimental tests, and the results presented are, in our opinion, both novel and
1997 annual ground control operating plan for the Waste Isolation Pilot Plant
Energy Technology Data Exchange (ETDEWEB)
NONE
1997-02-01
This plan presents background information and a working guide to assist Mine Operations and Engineering in developing strategies for addressing ground control issues at the Waste Isolation Pilot Plant (WIPP). With the anticipated receipt of waste in late 1997, this document provides additional detail to Panel 1 activities and options. The plan also serves as a foundation document for development and revision of the annual long-term ground control plan. Section 2.0 documents the current status of all underground excavations with respect to location, geology, geometry, age, ground support, operational use, projected life, and physical conditions. Section 3.0 presents the methods used to evaluate ground conditions, including visual observations of the roof, ribs, and floor, inspection of observation holes, and review of instrumentation data. Section 4.0 lists several ground support options and specific applications of each. Section 5.0 discusses remedial ground control measures that have been implemented to date. Section 6.0 presents projections and recommendations for ground control actions based on the information in Sections 2.0 through 5.0 of this plan and on a rating of the critical nature of each specific area. Section 7.0 presents a summary statement, and Section 8.0 includes references. Appendix A provides an overview and critique of ground control systems that have been, or may be, used at the site. Because of the dynamic nature of the underground openings and associated geotechnical activities, this plan will be revised as additional data are incorporated.
A monotonic method for solving nonlinear optimal control problems
Salomon, Julien
2009-01-01
Initially introduced in the framework of quantum control, the so-called monotonic algorithms have shown excellent numerical results when dealing with various bilinear optimal control problems. This paper aims at presenting a unified formulation of such procedures and the intrinsic assumptions they require. In this framework, we prove the feasibility of the general algorithm. Finally, we explain how these assumptions can be relaxed.
Do job demands and job control affect problem-solving?
Bergman, Peter N; Ahlberg, Gunnel; Johansson, Gun; Stoetzer, Ulrich; Aborg, Carl; Hallsten, Lennart; Lundberg, Ingvar
2012-01-01
The Job Demand Control model presents combinations of working conditions that may facilitate learning, the active learning hypothesis, or have detrimental effects on health, the strain hypothesis. To test the active learning hypothesis, this study analysed the effects of job demands and job control on general problem-solving strategies. A population-based sample of 4,636 individuals (55% women, 45% men) with the same job characteristics measured at two times with a three year time lag was used. Main effects of demands, skill discretion, task authority and control, and the combined effects of demands and control were analysed in logistic regressions, on four outcomes representing general problem-solving strategies. Those reporting high on skill discretion, task authority and control, as well as those reporting high demand/high control and low demand/high control job characteristics were more likely to state using problem solving strategies. Results suggest that working conditions including high levels of control may affect how individuals cope with problems and that workplace characteristics may affect behaviour in the non-work domain.
Directory of Open Access Journals (Sweden)
Weifeng Wang
2014-01-01
Full Text Available We study an optimal control problem governed by a semilinear parabolic equation, whose control variable is contained only in the boundary condition. An existence theorem for the optimal control is obtained.
Optimal control problems for impulsive systems with integral boundary conditions
Directory of Open Access Journals (Sweden)
Allaberen Ashyralyev
2013-03-01
Full Text Available In this article, the optimal control problem is considered when the state of the system is described by the impulsive differential equations with integral boundary conditions. Applying the Banach contraction principle the existence and uniqueness of the solution is proved for the corresponding boundary problem by the fixed admissible control. The first and second variation of the functional is calculated. Various necessary conditions of optimality of the first and second order are obtained by the help of the variation of the controls.
The Terahertz Controlled Duplex Isolator: Physical Grounds and Numerical Experiment
Directory of Open Access Journals (Sweden)
Konstantin Vytovtov
2016-01-01
Full Text Available Electromagnetic properties of an anisotropic stratified slab with an arbitrary orientation of the anisotropy axis under an oblique incidence of a plane harmonic wave are studied. The dependence of the eigenwave wavenumbers and the reflection coefficient on an anisotropy axis orientation and frequency is investigated. For the first time, the expression for the translation matrix is obtained in the compact analytical form. The controlled two-way dual-frequency (duplex isolator based on the above described slab is presented for the first time. It is based on the properties of the anisotropic structure described here but not on the Faraday effect.
Pushing the Limits of Cubesat Attitude Control: A Ground Demonstration
Sanders, Devon S.; Heater, Daniel L.; Peeples, Steven R.; Sules. James K.; Huang, Po-Hao Adam
2013-01-01
A cubesat attitude control system (ACS) was designed at the NASA Marshall Space Flight Center (MSFC) to provide sub-degree pointing capabilities using low cost, COTS attitude sensors, COTS miniature reaction wheels, and a developmental micro-propulsion system. The ACS sensors and actuators were integrated onto a 3D-printed plastic 3U cubesat breadboard (10 cm x 10 cm x 30 cm) with a custom designed instrument board and typical cubesat COTS hardware for the electrical, power, and data handling and processing systems. In addition to the cubesat development, a low-cost air bearing was designed and 3D printed in order to float the cubesat in the test environment. Systems integration and verification were performed at the MSFC Small Projects Rapid Integration & Test Environment laboratory. Using a combination of both the miniature reaction wheels and the micro-propulsion system, the open and closed loop control capabilities of the ACS were tested in the Flight Robotics Laboratory. The testing demonstrated the desired sub-degree pointing capability of the ACS and also revealed the challenges of creating a relevant environment for development testin
Overview of Krylov subspace methods with applications to control problems
Saad, Youcef
1989-01-01
An overview of projection methods based on Krylov subspaces are given with emphasis on their application to solving matrix equations that arise in control problems. The main idea of Krylov subspace methods is to generate a basis of the Krylov subspace Span and seek an approximate solution the the original problem from this subspace. Thus, the original matrix problem of size N is approximated by one of dimension m typically much smaller than N. Krylov subspace methods have been very successful in solving linear systems and eigenvalue problems and are now just becoming popular for solving nonlinear equations. It is shown how they can be used to solve partial pole placement problems, Sylvester's equation, and Lyapunov's equation.
Infinite Horizon Discrete Time Control Problems for Bounded Processes
Directory of Open Access Journals (Sweden)
Hayek Naïla
2008-01-01
Full Text Available We establish Pontryagin Maximum Principles in the strong form for infinite horizon optimal control problems for bounded processes, for systems governed by difference equations. Results due to Ioffe and Tihomirov are among the tools used to prove our theorems. We write necessary conditions with weakened hypotheses of concavity and without invertibility, and we provide new results on the adjoint variable. We show links between bounded problems and nonbounded ones. We also give sufficient conditions of optimality.
Infinite Horizon Discrete Time Control Problems for Bounded Processes
Directory of Open Access Journals (Sweden)
2009-03-01
Full Text Available We establish Pontryagin Maximum Principles in the strong form for infinite horizon optimal control problems for bounded processes, for systems governed by difference equations. Results due to Ioffe and Tihomirov are among the tools used to prove our theorems. We write necessary conditions with weakened hypotheses of concavity and without invertibility, and we provide new results on the adjoint variable. We show links between bounded problems and nonbounded ones. We also give sufficient conditions of optimality.
Bolton, Jeremy; Gader, Paul; Frigui, Hichem
2013-06-01
Multiple Instance Learning is a recently researched learning paradigm in machine intelligence which operates under conditions of uncertainty with the cost of increased computational burden. This increase in computational burden can be avoided by embedding these so-called multiple instances using a kernel function or other embedding function. In the following, a family of fast multiple instance relevance vector machines are used to learn and classify landmine signatures in ground penetrating radar data. Results indicate a significant reduction in computational complexity without a loss in classification accuracy in operating conditions.
Indirect Radau pseudospectral method for the receding horizon control problem
Directory of Open Access Journals (Sweden)
Yuxin Liao
2016-02-01
Full Text Available To solve the receding horizon control (RHC problem in an online manner, a novel numerical method called the indirect Radau pseudospectral method (IRPM is proposed in this paper. Based on calculus of variations and the first-order necessary optimality condition, the RHC problem for linear time-varying (LTV system is transformed into the two-point boundary value problem (TPBVP. The Radau pseudospectral approximation is employed to discretize the TPBVP into well-posed linear algebraic equations. The resulting linear algebraic equations are solved via a matrix partitioning approach afterwards to obtain the optimal feedback control law. For the nonlinear system, the linearization method or the quasi linearization method is employed to approximate the RHC problem with successive linear approximations. Subsequently, each linear problem is solved via the similar method which is used to solve the RHC problem for LTV system. Simulation results of three examples show that the IRPM is of high accuracy and of high computation efficiency to solve the RHC problem and the stability of closed-loop systems is guaranteed.
Indirect Radau pseudospectral method for the receding horizon control problem
Institute of Scientific and Technical Information of China (English)
Liao Yuxin; Li Huifeng; Bao Weimin
2016-01-01
To solve the receding horizon control (RHC) problem in an online manner, a novel numerical method called the indirect Radau pseudospectral method (IRPM) is proposed in this paper. Based on calculus of variations and the first-order necessary optimality condition, the RHC problem for linear time-varying (LTV) system is transformed into the two-point boundary value problem (TPBVP). The Radau pseudospectral approximation is employed to discretize the TPBVP into well-posed linear algebraic equations. The resulting linear algebraic equations are solved via a matrix partitioning approach afterwards to obtain the optimal feedback control law. For the nonlinear system, the linearization method or the quasi linearization method is employed to approximate the RHC problem with successive linear approximations. Subsequently, each linear problem is solved via the similar method which is used to solve the RHC problem for LTV system. Simulation results of three examples show that the IRPM is of high accuracy and of high compu-tation efficiency to solve the RHC problem and the stability of closed-loop systems is guaranteed.
Galerkin approximations of nonlinear optimal control problems in Hilbert spaces
Directory of Open Access Journals (Sweden)
Mickael D. Chekroun
2017-07-01
Full Text Available Nonlinear optimal control problems in Hilbert spaces are considered for which we derive approximation theorems for Galerkin approximations. Approximation theorems are available in the literature. The originality of our approach relies on the identification of a set of natural assumptions that allows us to deal with a broad class of nonlinear evolution equations and cost functionals for which we derive convergence of the value functions associated with the optimal control problem of the Galerkin approximations. This convergence result holds for a broad class of nonlinear control strategies as well. In particular, we show that the framework applies to the optimal control of semilinear heat equations posed on a general compact manifold without boundary. The framework is then shown to apply to geoengineering and mitigation of greenhouse gas emissions formulated here in terms of optimal control of energy balance climate models posed on the sphere $\\mathbb{S}^2$.
Feed forward and feedback control for over-ground locomotion in anaesthetized cats
Mazurek, K. A.; Holinski, B. J.; Everaert, D. G.; Stein, R. B.; Etienne-Cummings, R.; Mushahwar, V. K.
2012-04-01
The biological central pattern generator (CPG) integrates open and closed loop control to produce over-ground walking. The goal of this study was to develop a physiologically based algorithm capable of mimicking the biological system to control multiple joints in the lower extremities for producing over-ground walking. The algorithm used state-based models of the step cycle each of which produced different stimulation patterns. Two configurations were implemented to restore over-ground walking in five adult anaesthetized cats using intramuscular stimulation (IMS) of the main hip, knee and ankle flexor and extensor muscles in the hind limbs. An open loop controller relied only on intrinsic timing while a hybrid-CPG controller added sensory feedback from force plates (representing limb loading), and accelerometers and gyroscopes (representing limb position). Stimulation applied to hind limb muscles caused extension or flexion in the hips, knees and ankles. A total of 113 walking trials were obtained across all experiments. Of these, 74 were successful in which the cats traversed 75% of the 3.5 m over-ground walkway. In these trials, the average peak step length decreased from 24.9 ± 8.4 to 21.8 ± 7.5 (normalized units) and the median number of steps per trial increased from 7 (Q1 = 6, Q3 = 9) to 9 (8, 11) with the hybrid-CPG controller. Moreover, within these trials, the hybrid-CPG controller produced more successful steps (step length ≤ 20 cm ground reaction force ≥ 12.5% body weight) than the open loop controller: 372 of 544 steps (68%) versus 65 of 134 steps (49%), respectively. This supports our previous preliminary findings, and affirms that physiologically based hybrid-CPG approaches produce more successful stepping than open loop controllers. The algorithm provides the foundation for a neural prosthetic controller and a framework to implement more detailed control of locomotion in the future.
Impulse control in Kalman-like filtering problems
Directory of Open Access Journals (Sweden)
Michael V. Basin
1998-01-01
Full Text Available This paper develops the impulse control approach to the observation process in Kalman-like filtering problems, which is based on impulsive modeling of the transition matrix in an observation equation. The impulse control generates the jumps of the estimate variance from its current position down to zero and, as a result, enables us to obtain the filtering equations for the Kalman estimate with zero variance for all post-jump time moments. The filtering equations for the estimates with zero variances are obtained in the conventional linear filtering problem and in the case of scalar nonlinear state and nonlinear observation equations.
Optimal Control Problems for Partial Differential Equations on Reticulated Domains
Kogut, Peter I
2011-01-01
In the development of optimal control, the complexity of the systems to which it is applied has increased significantly, becoming an issue in scientific computing. In order to carry out model-reduction on these systems, the authors of this work have developed a method based on asymptotic analysis. Moving from abstract explanations to examples and applications with a focus on structural network problems, they aim at combining techniques of homogenization and approximation. Optimal Control Problems for Partial Differential Equations on Reticulated Domains is an excellent reference tool for gradu
De Groote, Friedl; Kinney, Allison L; Rao, Anil V; Fregly, Benjamin J
2016-10-01
Estimation of muscle forces during motion involves solving an indeterminate problem (more unknown muscle forces than joint moment constraints), frequently via optimization methods. When the dynamics of muscle activation and contraction are modeled for consistency with muscle physiology, the resulting optimization problem is dynamic and challenging to solve. This study sought to identify a robust and computationally efficient formulation for solving these dynamic optimization problems using direct collocation optimal control methods. Four problem formulations were investigated for walking based on both a two and three dimensional model. Formulations differed in the use of either an explicit or implicit representation of contraction dynamics with either muscle length or tendon force as a state variable. The implicit representations introduced additional controls defined as the time derivatives of the states, allowing the nonlinear equations describing contraction dynamics to be imposed as algebraic path constraints, simplifying their evaluation. Problem formulation affected computational speed and robustness to the initial guess. The formulation that used explicit contraction dynamics with muscle length as a state failed to converge in most cases. In contrast, the two formulations that used implicit contraction dynamics converged to an optimal solution in all cases for all initial guesses, with tendon force as a state generally being the fastest. Future work should focus on comparing the present approach to other approaches for computing muscle forces. The present approach lacks some of the major limitations of established methods such as static optimization and computed muscle control while remaining computationally efficient.
Portable Ground Measurement & Control System%便携式地面测控系统
Institute of Scientific and Technical Information of China (English)
罗珊; 陈睿璟; 路引; 张哲聪
2012-01-01
为适应无人机地面测控技术的发展要求,设计一种便携式无人机地面控制系统.分析便携式无人机控制系统的基本技术和原理,着重探究便携式地面测控系统的工作原理,通过采用操纵杆和键盘指令由测控计算机完成向无人机靶机发送遥控指令.试验和测试结果表明,所设计的无人机靶机地面测控系统具有一定的可行性.%In order to meet the development requirement of UAV ground measurement & control technology, design a portable UVA ground control system. Analyze the basic technology and principle of portable UAV control system. Pay much attention to working principle of the UAV ground measurement and control system. Realize measurement and control computer sending remote command to UAV target drone by using joy stick and keyboard command. The test results show that the design of the UAV target drone ground measurement & control system is feasible.
Adjoint optimal control problems for the RANS system
Attavino, A.; Cerroni, D.; Da Vià, R.; Manservisi, S.; Menghini, F.
2017-01-01
Adjoint optimal control in computational fluid dynamics has become increasingly popular recently because of its use in several engineering and research studies. However the optimal control of turbulent flows without the use of Direct Numerical Simulation is still an open problem and various methods have been proposed based on different approaches. In this work we study optimal control problems for a turbulent flow modeled with a Reynolds-Averaged Navier-Stokes system. The adjoint system is obtained through the use of a Lagrangian multiplier method by setting as objective of the control a velocity matching profile or an increase or decrease in the turbulent kinetic energy. The optimality system is solved with an in-house finite element code and numerical results are reported in order to show the validity of this approach.
Tackling five main problem areas found in science (ground segment) project developments
Lock, T.; Pérez-López, F.
2014-08-01
Science projects which require a large software development may use many scientists alongside a few professional software engineers. Such projects tend to show extreme cases of the general problems associated with software developments. After introducing an example of a large software development in a science project, the importance of a development management plan will be emphasised and sections of the plan highlighted and it is explained how these sections address and prepare for the expected problems throughout the life of the project. A positive, strongly proactive quality assurance, QA, approach is the common theme throughout. The role of QA is, therefore, more to guide, support and advise all members of the team rather than only to detect and react to problems. The top five problem areas addressed are: 1. Vague, late and missing requirements. 2. Few professional software engineers in a large software development. 3. A lack of testers with an appropriate test mentality. 4. Quality Assurance people cannot be everywhere, nor have in-depth skills in every subject. 5. Scientists will want to start coding and see writing documents as a waste of their time.
An Application of Signal Analysis and Pattern Recognition to Study a Simple Ground Motion Problem.
1986-08-01
via Visual Examination 40 Table 4. List of Features 41 Table 5. Basic Studies - Prediction Results 43 Table 6. Single Feature Study - Prediction Results...CCC CCC D -4-- CD0000 -~ - - z a -44 39- TABLE 3. POOR WAVEFORMS VIA VISUAL EXAMINATION Test/Gage Problem A304* bandedge A306 probable gage failure, TOA
The heat treatment of steel. A mathematical control problem
Energy Technology Data Exchange (ETDEWEB)
Hoemberg, Dietmar; Kern, Daniela
2009-07-21
The goal of this paper is to show how the heat treatment of steel can be modelled in terms of a mathematical optimal control problem. The approach is applied to laser surface hardening and the cooling of a steel slab including mechanical effects. Finally, it is shown how the results can be utilized in industrial practice by a coupling with machine-based control. (orig.)
Abstraction and control techniques for non-stationary scheduling problems
Innocenti, Giacomo
2009-01-01
The paper faces the problem of scheduling from a new perspective, trying to bridge the gap between classical heuristic approaches and system identification and control strategies. To this aim, a complete mathematical formulation of a general scheduling process is derived, beginning from very broad assumptions. This allows a greater freedom of manipulation and guarantee the resolution of the identification (and control) techniques. Both an adaptive and a switching strategies are presented in relation to the performances of a simple Round Robin algorithm.
Incremental planning to control a blackboard-based problem solver
Durfee, E. H.; Lesser, V. R.
1987-01-01
To control problem solving activity, a planner must resolve uncertainty about which specific long-term goals (solutions) to pursue and about which sequences of actions will best achieve those goals. A planner is described that abstracts the problem solving state to recognize possible competing and compatible solutions and to roughly predict the importance and expense of developing these solutions. With this information, the planner plans sequences of problem solving activities that most efficiently resolve its uncertainty about which of the possible solutions to work toward. The planner only details actions for the near future because the results of these actions will influence how (and whether) a plan should be pursued. As problem solving proceeds, the planner adds new details to the plan incrementally, and monitors and repairs the plan to insure it achieves its goals whenever possible. Through experiments, researchers illustrate how these new mechanisms significantly improve problem solving decisions and reduce overall computation. They briefly discuss current research directions, including how these mechanisms can improve a problem solver's real-time response and can enhance cooperation in a distributed problem solving network.
A novel intelligent adaptive control of laser-based ground thermal test
Directory of Open Access Journals (Sweden)
Gan Zhengtao
2016-08-01
Full Text Available Laser heating technology is a type of potential and attractive space heat flux simulation technology, which is characterized by high heating rate, controlled spatial intensity distribution and rapid response. However, the controlled plant is nonlinear, time-varying and uncertainty when implementing the laser-based heat flux simulation. In this paper, a novel intelligent adaptive controller based on proportion–integration–differentiation (PID type fuzzy logic is proposed to improve the performance of laser-based ground thermal test. The temperature range of thermal cycles is more than 200 K in many instances. In order to improve the adaptability of controller, output scaling factors are real time adjusted while the thermal test is underway. The initial values of scaling factors are optimized using a stochastic hybrid particle swarm optimization (H-PSO algorithm. A validating system has been established in the laboratory. The performance of the proposed controller is evaluated through extensive experiments under different operating conditions (reference and load disturbance. The results show that the proposed adaptive controller performs remarkably better compared to the conventional PID (PID controller and the conventional PID type fuzzy (F-PID controller considering performance indicators of overshoot, settling time and steady state error for laser-based ground thermal test. It is a reliable tool for effective temperature control of laser-based ground thermal test.
A novel intelligent adaptive control of laser-based ground thermal test
Institute of Scientific and Technical Information of China (English)
Gan Zhengtao; Yu Gang; Li Shaoxia; He Xiuli; Chen Ru; Zheng Caiyun; Ning Weijian
2016-01-01
Laser heating technology is a type of potential and attractive space heat flux simulation technology, which is characterized by high heating rate, controlled spatial intensity distribution and rapid response. However, the controlled plant is nonlinear, time-varying and uncertainty when implementing the laser-based heat flux simulation. In this paper, a novel intelligent adaptive controller based on proportion–integration–differentiation (PID) type fuzzy logic is proposed to improve the performance of laser-based ground thermal test. The temperature range of thermal cycles is more than 200 K in many instances. In order to improve the adaptability of controller, output scaling factors are real time adjusted while the thermal test is underway. The initial values of scaling factors are optimized using a stochastic hybrid particle swarm optimization (H-PSO) algorithm. A validating system has been established in the laboratory. The performance of the pro-posed controller is evaluated through extensive experiments under different operating conditions (reference and load disturbance). The results show that the proposed adaptive controller performs remarkably better compared to the conventional PID (PID) controller and the conventional PID type fuzzy (F-PID) controller considering performance indicators of overshoot, settling time and steady state error for laser-based ground thermal test. It is a reliable tool for effective temperature control of laser-based ground thermal test.
Problems of Controlled Vocabulary versus Uncontrolled Vocabulary in Subject Indexing
Directory of Open Access Journals (Sweden)
Chao-chen Chen
1998-12-01
Full Text Available This article is mainly to survey the centennial controversy between controlled vocabulary v. uncontrolled vocabulary of subject indexing in the western library and information society. We also discuss the related problems in Chinese information retrieval systems and analyze the factors affecting their performance. [Article content in Chinese
On global error estimation and control for initial value problems
J. Lang; J.G. Verwer
2007-01-01
Abstract. This paper addresses global error estimation and control for initial value problems for ordinary differential equations. The focus lies on a comparison between a novel approach based on the adjoint method combined with a small sample statistical initialization and the classical approach ba
Structural analysis of complex ecological economic optimal control problems
Kiseleva, T.
2011-01-01
This thesis demonstrates the importance and effectiveness of methods of bifurcation theory applied to studying non-convex optimal control problems. It opens up a new methodological approach to investigation of parameterized economic models. While standard analytical methods are not efficient and
On global error estimation and control for initial value problems
Lang, J.; Verwer, J.G.
2007-01-01
Abstract. This paper addresses global error estimation and control for initial value problems for ordinary differential equations. The focus lies on a comparison between a novel approach based on the adjoint method combined with a small sample statistical initialization and the classical approach
Using Model Checking for Analyzing Distributed Power Control Problems
DEFF Research Database (Denmark)
Brihaye, Thomas; Jungers, Marc; Lasaulce, Samson
2010-01-01
Model checking (MC) is a formal verification technique which has been known and still knows a resounding success in the computer science community. Realizing that the distributed power control ( PC) problem can be modeled by a timed game between a given transmitter and its environment, the authors...
Approximated analytical solution to an Ebola optimal control problem
Hincapié-Palacio, Doracelly; Ospina, Juan; Torres, Delfim F. M.
2016-11-01
An analytical expression for the optimal control of an Ebola problem is obtained. The analytical solution is found as a first-order approximation to the Pontryagin Maximum Principle via the Euler-Lagrange equation. An implementation of the method is given using the computer algebra system Maple. Our analytical solutions confirm the results recently reported in the literature using numerical methods.
Higuchi, S.; Allen, G.; Bencze, W.; Byer, R.; Dang, A.; DeBra, D. B.; Lauben, D.; Dorlybounxou, S.; Hanson, J.; Ho, L.; Huffman, G.; Sabur, F.; Sun, K.; Tavernetti, R.; Rolih, L.; Van Patten, R.; Wallace, J.; Williams, S.
2006-03-01
This article demonstrates experimental results of a thermal control system developed for ST-7 gravitational reference sensor (GRS) ground verification testing which provides thermal stability δT control of the LISA spacecraft to compensate solar irradiate 1/f fluctuations. Although for ground testing these specifications can be met fairly readily with sufficient insulation and thermal mass, in contrast, for spacecraft the very limited thermal mass calls for an active control system which can simultaneously meet disturbance rejection and stability requirements in the presence of long time delay; a considerable design challenge. Simple control laws presently provide ~ 1mK/surdHz for >24 hours. Continuing development of a model predictive feedforward control algorithm will extend performance to <1 mK/surdHz at f < 0.01 mHz and possibly lower, extending LISA coverage of super massive black hole mergers.
Spin-Orbit Coupling Controlled J =3 /2 Electronic Ground State in 5 d3 Oxides
Taylor, A. E.; Calder, S.; Morrow, R.; Feng, H. L.; Upton, M. H.; Lumsden, M. D.; Yamaura, K.; Woodward, P. M.; Christianson, A. D.
2017-05-01
Entanglement of spin and orbital degrees of freedom drives the formation of novel quantum and topological physical states. Here we report resonant inelastic x-ray scattering measurements of the transition metal oxides Ca3 LiOsO6 and Ba2 YOsO6 , which reveals a dramatic spitting of the t2 g manifold. We invoke an intermediate coupling approach that incorporates both spin-orbit coupling and electron-electron interactions on an even footing and reveal that the ground state of 5 d3-based compounds, which has remained elusive in previously applied models, is a novel spin-orbit entangled J =3 /2 electronic ground state. This work reveals the hidden diversity of spin-orbit controlled ground states in 5 d systems and introduces a new arena in the search for spin-orbit controlled phases of matter.
Kreifeldt, J. G.; Parkin, L.; Wempe, T. E.; Huff, E. F.
1975-01-01
Perceived orderliness in the ground tracks of five A/C during their simulated flights was studied. Dynamically developing ground tracks for five A/C from 21 separate runs were reproduced from computer storage and displayed on CRTS to professional pilots and controllers for their evaluations and preferences under several criteria. The ground tracks were developed in 20 seconds as opposed to the 5 minutes of simulated flight using speedup techniques for display. Metric and nonmetric multidimensional scaling techniques are being used to analyze the subjective responses in an effort to: (1) determine the meaningfulness of basing decisions on such complex subjective criteria; (2) compare pilot/controller perceptual spaces; (3) determine the dimensionality of the subjects' perceptual spaces; and thereby (4) determine objective measures suitable for comparing alternative traffic management simulations.
Three-body problem in 3D space: ground state, (quasi)-exact-solvability
Turbiner, Alexander V; Escobar-Ruiz, Adrian M
2016-01-01
We study aspects of the quantum and classical dynamics of a $3$-body system in 3D space with interaction depending only on mutual distances. The study is restricted to solutions in the space of relative motion which are functions of mutual distances only. It is shown that the ground state (and some other states) in the quantum case and the planar trajectories in the classical case are of this type. The quantum (and classical) system for which these states are eigenstates is found and its Hamiltonian is constructed. It corresponds to a three-dimensional quantum particle moving in a curved space with special metric. The kinetic energy of the system has a hidden $sl(4,R)$ Lie (Poisson) algebra structure, alternatively, the hidden algebra $h^{(3)}$ typical for the $H_3$ Calogero model. We find an exactly solvable three-body generalized harmonic oscillator-type potential as well as a quasi-exactly-solvable three-body sextic polynomial type potential.
The Similar Structures and Control Problems of Complex Systems
Institute of Scientific and Technical Information of China (English)
无
2002-01-01
In this paper, the naturally evolving complex systems, such as biotic and social ones, are considered. Focusing on their structures, a feature is noteworthy, i.e., the similarity in structures. The relations between the functions and behaviors of these systems and their similar structures will be studied. Owing to the management of social systems and the course of evolution of biotic systems may be regarded as control processes, the researches will be within the scope of control problems. Moreover, since it is difficult to model for biotic and social systems, it will start with the control problems of complex systems, possessing similar structures, in engineering.The obtained results show that for either linear or nonlinear systems and for a lot of control problemssimilar structures lead to a series of simplifications. In general, the original system may be decomposed into reduced amount of subsystems with lower dimensions and simpler structures. By virtue of such subsystems, the control problems of original system can be solved more simply.At last, it turns round to observe the biotic and social systems and some analyses are given.
User Control Problems and Taking User Empowerment Further
Rodrigues, Rowena
User control in identity management is beset with a number of problems, as outlined in this paper. It is argued that akin to traditional contexts, greater user control will result in greater user liability, which is demonstrated with the help of digital and non-digital examples. In this context, there is a critical need for greater user empowerment. This could be achieved in two ways-first, facilitating user awareness of identity management technologies, their scope and effects and second, through the implementation of proposed control-liability notices.
Multiresolution strategies for the numerical solution of optimal control problems
Jain, Sachin
There exist many numerical techniques for solving optimal control problems but less work has been done in the field of making these algorithms run faster and more robustly. The main motivation of this work is to solve optimal control problems accurately in a fast and efficient way. Optimal control problems are often characterized by discontinuities or switchings in the control variables. One way of accurately capturing the irregularities in the solution is to use a high resolution (dense) uniform grid. This requires a large amount of computational resources both in terms of CPU time and memory. Hence, in order to accurately capture any irregularities in the solution using a few computational resources, one can refine the mesh locally in the region close to an irregularity instead of refining the mesh uniformly over the whole domain. Therefore, a novel multiresolution scheme for data compression has been designed which is shown to outperform similar data compression schemes. Specifically, we have shown that the proposed approach results in fewer grid points in the grid compared to a common multiresolution data compression scheme. The validity of the proposed mesh refinement algorithm has been verified by solving several challenging initial-boundary value problems for evolution equations in 1D. The examples have demonstrated the stability and robustness of the proposed algorithm. The algorithm adapted dynamically to any existing or emerging irregularities in the solution by automatically allocating more grid points to the region where the solution exhibited sharp features and fewer points to the region where the solution was smooth. Thereby, the computational time and memory usage has been reduced significantly, while maintaining an accuracy equivalent to the one obtained using a fine uniform mesh. Next, a direct multiresolution-based approach for solving trajectory optimization problems is developed. The original optimal control problem is transcribed into a
Energy Technology Data Exchange (ETDEWEB)
Flach, G.P.; Rehder, T.E.; Kanzleiter, J.P.
1996-10-02
This report has been developed to support information needs for wastes buried in the Burial Ground Complex. Information discussed is presented in a total of four individual attachments. The general focus of this report is to collect information on estimated source inventories, leaching studies, source control technologies, and to provide information on modeling parameters and associated data deficiencies.
Geometric Calibration of ZIYUAN-3 Three-Line Cameras Combining Ground Control Points and Lines
Cao, Jinshan; Yuan, Xiuxiao; Gong, Jianya
2016-06-01
Due to the large biases between the laboratory-calibrated values of the orientation parameters and their in-orbit true values, the initial direct georeferencing accuracy of the Ziyuan-3 (ZY-3) three-line camera (TLC) images can only reach the kilometre level. In this paper, a point-based geometric calibration model of the ZY-3 TLCs is firstly established by using the collinearity constraint, and then a line-based geometric calibration model is established by using the coplanarity constraint. With the help of both the point-based and the line-based models, a feasible in-orbit geometric calibration approach for the ZY-3 TLCs combining ground control points (GCPs) and ground control lines (GCLs) is presented. Experimental results show that like GCPs, GCLs can also provide effective ground control information for the geometric calibration of the ZY-3 TLCs. The calibration accuracy of the look angles of charge-coupled device (CCD) detectors achieved by using the presented approach reached up to about 1.0''. After the geometric calibration, the direct georeferencing accuracy of the ZY-3 TLC images without ground controls was significantly improved from the kilometre level to better than 11 m in planimetry and 9 m in height. A more satisfactory georeferencing accuracy of better than 3.5 m in planimetry and 3.0 m in height was achieved after the block adjustment with four GCPs.
PROBLEMS OF HOMOSEXUALITY PERCEPTION IN MODERN RUSSIA: GROUNDS OF THE RELEVANT DISCOURSE
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Vadim Vadimovich Kortunov
2015-11-01
Full Text Available In 2013, the State Duma of the Russian Federation adopted the Federal Law «On the prohibition of propaganda of nontraditional sexual relations among minors», which provoked a lot of discussions in the media between sexual minorities and their opponents: the former began to criticize this law as the one prejudicing their rights, the latter after a long silence renewed their attacks against homosexuals. It served as a basis for sociologists to assume that homophobia is reviving in Russia. In the article we made an attempt to see into the arguments of opponents of nontraditional sexual orientation and to trace the belief origins of «Russian homophobia». To do this, the authors of this scoping study are trying to answer the following questions: is it correct to justify homosexuality as a norm of behavior, referring to homosexual behavior of animals, to what extent is homosexuality due to the norms of the Russian culture, what its contribution to the art, what do the world religions say about same-sex relationships, what is its impact on the society development, what is the opinion of modern medicine on this phenomenon. In this paper the authors attempt to reproduce the arguments of homophobic logic, which is so widespread in today’s Russia, to understand its origins and ideological grounds. This is done solely in order to find compromises and to develop balanced, tolerant positions from both sides. The authors hope that the ideas expressed in this article will be helpful in the matter of resolving such significant socio-cultural issue as the opposition of homo- and heterosexuals, and will make a modest contribution to the protection of human rights and freedoms in the Russian Federation.
The Next Generation of Ground Operations Command and Control; Scripting in C no. and Visual Basic
Ritter, George; Pedoto, Ramon
2010-01-01
Scripting languages have become a common method for implementing command and control solutions in space ground operations. The Systems Test and Operations Language (STOL), the Huntsville Operations Support Center (HOSC) Scripting Language Processor (SLP), and the Spacecraft Control Language (SCL) offer script-commands that wrap tedious operations tasks into single calls. Since script-commands are interpreted, they also offer a certain amount of hands-on control that is highly valued in space ground operations. Although compiled programs seem to be unsuited for interactive user control and are more complex to develop, Marshall Space flight Center (MSFC) has developed a product called the Enhanced and Redesign Scripting (ERS) that makes use of the graphical and logical richness of a programming language while offering the hands-on and ease of control of a scripting language. ERS is currently used by the International Space Station (ISS) Payload Operations Integration Center (POIC) Cadre team members. ERS integrates spacecraft command mnemonics, telemetry measurements, and command and telemetry control procedures into a standard programming language, while making use of Microsoft's Visual Studio for developing Visual Basic (VB) or C# ground operations procedures. ERS also allows for script-style user control during procedure execution using a robust graphical user input and output feature. The availability of VB and C# programmers, and the richness of the languages and their development environment, has allowed ERS to lower our "script" development time and maintenance costs at the Marshall POIC.
Greenman, D.W.; Swarzenski, W.V.; Bennett, G.D.
1967-01-01
Rising water tables and the salinization of land as the result of canal irrigation threaten the agricultural economy of the Punjab. Since 1954 the Water and Soils Investigation Division of the West Pakistan Water and Power Development Authority has inventoried the water and soils resources of the Punjab and investigated the relations between irrigation activities, the natural hydrologic factors, and the incidence of waterlogging and subsurface-drainage problems. This report summarizes the findings of the investigation, which was carried out under a cooperative agreement between the Government of Pakistan and the U.S. Agency for International Development, and its predecessor, the U.S. International Cooperation Administration. Leakage from the canal systems, some of which have been in operation for more than 100 years, is the principal cause of rising water levels and constitutes the major component of ground-water recharge in the Punjab. Geologic studies have shown that virtually the entire Punjab is underlain to depths of 1,000 feet or more by unconsolidated alluvium, which is saturated to within a few feet of land surface. The alluvium varies in texture from medium sand to silty clay, but sandy sediments predominate. Large capacity wells, yielding 4 cfs or more, can be developed almost everywhere. Ground water occurring within a depth of 500 feet below the surface averages less than 1,000 ppm of dissolved solids throughout approximately two-thirds of the Punjab. It is estimated that the volume of usable ground water in storage in this part of the alluvial aquifer is on the order of 2 billion acre-feet. In the other one-third of the Punjab, total dissolved solids range from 1,000 to about 20,000 ppm. In about one-half of this area (one-sixth of the area of the Punjab) some ground water can be utilized by diluting with surface water from canals. The ground-water reservoir underlying the Punjab is an unexploited resource of enormous economic value. It is recognized
Keum, Jung-Hoon; Ra, Sung-Woong
2009-12-01
Nonlinear sliding surface design in variable structure systems for spacecraft attitude control problems is studied. A robustness analysis is performed for regular form of system, and calculation of actuator bandwidth is presented by reviewing sliding surface dynamics. To achieve non-singular attitude description and minimal parameterization, spacecraft attitude control problems are considered based on modified Rodrigues parameters (MRP). It is shown that the derived controller ensures the sliding motion in pre-determined region irrespective of unmodeled effects and disturbances.
Identification of Fungal Colonies on Ground Control and Flight Veggie Plant Pillows
Scotten, Jessica E.; Hummerick, Mary E.; Khodadad, Christina L.; Spencer, Lashelle E.; Massa, Gioia D.
2017-01-01
The Veggie system focuses on growing fresh produce that can be harvested and consumed by astronauts. The microbial colonies in each Veggie experiment are evaluated to determine the safety level of the produce and then differences between flight and ground samples. The identifications of the microbial species can detail risks or benefits to astronaut and plant health. Each Veggie ground or flight experiment includes six plants grown from seeds that are glued into wicks in Teflon pillows filled with clay arcillite and fertilizer. Fungal colonies were isolated from seed wicks, growth media, and lettuce (cv. 'Outredgeous') roots grown in VEG-01B pillows on ISS and in corresponding ground control pillows grown in controlled growth chambers. The colonies were sorted by morphology and identified using MicroSeq(TM) 500 16s rDNA Bacterial Identification System and BIOLOG GEN III MicroPlate(TM). Health risks for each fungal identification were then assessed using literature sources. The goal was to identify all the colonies isolated from flight and ground control VEG-01B plants, roots, and rooting medium and compare the resulting identifications.
Vibrating barrier: a novel device for the passive control of structures under ground motion.
Cacciola, P; Tombari, A
2015-07-08
A novel device, called vibrating barrier (ViBa), that aims to reduce the vibrations of adjacent structures subjected to ground motion waves is proposed. The ViBa is a structure buried in the soil and detached from surrounding buildings that is able to absorb a significant portion of the dynamic energy arising from the ground motion. The working principle exploits the dynamic interaction among vibrating structures due to the propagation of waves through the soil, namely the structure-soil-structure interaction. The underlying theoretical aspects of the novel control strategy are scrutinized along with its numerical modelling. Closed-form solutions are also derived to design the ViBa in the case of harmonic excitation. Numerical and experimental analyses are performed in order to investigate the efficiency of the device in mitigating the effects of ground motion waves on the structural response. A significant reduction in the maximum structural acceleration of 87% has been achieved experimentally.
Parareal in time intermediate targets methods for optimal control problem
Maday, Yvon; Salomon, Julien
2012-01-01
In this paper, we present a method that enables solving in parallel the Euler-Lagrange system associated with the optimal control of a parabolic equation. Our approach is based on an iterative update of a sequence of intermediate targets that gives rise to independent sub-problems that can be solved in parallel. This method can be coupled with the parareal in time algorithm. Numerical experiments show the efficiency of our method.
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Alvaro Vargas-Clara
2015-02-01
Full Text Available In this paper, we implement a novel control strategy for navigation of an Unmanned Ground Vehicle (UGV. This strategy consisted in the development and implementation of the Brain Emotional Learning Based Intelligent Controller (BELBIC for heading, and path control of a UGV. BELBIC is an intelligent controller based on the model of the Amygdala-Orbitofrontal system of mammalians, which is a region in the brain known to be responsible for emotional learning process. Simulation of this controller for the cases of heading, and path control showed to be very robust and adaptable to dynamical changes in the plant. A comparison between BELBIC and a traditional PID control is presented to illustrate the performance of this control strategy.
Ground-remote control for space station telerobotics with time delay
Backes, Paul G.
1992-01-01
The study proposes a ground-remote telerobot control architecture which could be used for control of Space Station Freedom manipulators. The architecture provides two local-site operator control stations representing potential earth-based and remote Space Station-based operator control stations. A unified control system at the remote site provides autonomous, shared, and teleoperation control for single-and dual-arm task execution. An operational laboratory system which demonstrates the feasibility of various technologies in the proposed architecture, including teleoperation, shared control, and supervised autonomy, is described. Enhancements to the system currently under development, including remote site implementation in Ada, integration and control of a redundant 7-DOF manipulator, and local site advanced operator aids, are also described.
LEGAL SUPPORT FOR PUBLIC CONTROL: PROBLEMS AND PROSPECTS
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Savchenko M. S.
2015-06-01
Full Text Available In the article we reveal the basic problems of forming the legal basis of public control over the activities of public authorities. The relevance of this topic has been steadily increasing due to the increasing influence of civil society on the decisions made by public authorities. The authors analyze the provisions of the Federal Law "On the basis of public control in the Russian Federation", the regional laws, to fix the foundations of social control in some subjects of the federation, as well as other legal acts in this area. Special attention is paid to the formulation of the concept of social control and the conclusion of the need legislative consolidation of the concept of "individual public authority 'and a common list of agencies and organizations that operate them. Analyzing the law enshrined in the range of subjects of public control, the authors substantiate the feasibility of incorporating the Advisory Board at the government and public experts. On the basis of the provisions of the law, in this work we have determined the legal status of the subjects of social control, their powers and procedures of the in collaboration with the authorities, as well as the legal framework for the implementation of certain forms of social control. It is proposed to expand the interaction of subjects of public control with prosecutors by holding regular meetings to expand the powers of public monitoring commissions for visiting places of detention
DESIGNING REDUCED-ORDER CONTROLLERS OF MIXED SENSITIVITY PROBLEM FOR FLIGHT CONTROL SYSTEMS
Institute of Scientific and Technical Information of China (English)
无
2000-01-01
Based on linear matrix inequalities (LMI), the design method of reduced-order controllers of mixed sensitivity problem is studied for flight control systems. It is shown that there exists a controller with order not greater than the difference between the generalized plant order and the number of independent control variables, if the mixed sensitivity problem is solvable for strict regular flight control plants. The proof is constructive, and an approach to design such a controller can be obtained in terms of a pair of feasible solution to the well-known 3 LMI. Finally, an example of mixed sensitivity problem for a flight control system is given to demonstrate practice of the approach.
Application of oil spill model to marine pollution and risk control problems
Aseev, Nikita; Agoshkov, Valery; Sheloput, Tatyana
2017-04-01
Oil transportation by sea induces challenging problems of environmental control. Millions of tonnes of oil are yearly released during routine ship operations, not to mention vast spills due to different accidents (e.g. tanker collisions, grounding, etc.). Oil pollution is dangerous to marine organisms such as plants, fish and mammals, leading to widespread damage to our planet. In turn, fishery and travel agencies can lose money and clients, and ship operators are obliged to pay huge penalties for environmental pollution. In this work we present the method of accessing oil pollution of marine environment using recently developed oil spill model. The model describes basic processes of the oil slick evolution: oil transport due to currents, drift under the action of wind, spreading on the surface, evaporation, emulsification and dispersion. Such parameters as slick location, mass, density of oil, water content, viscosity and density of "water-in-oil" emulsion can be calculated. We demonstrate how to apply the model to damage calculation problems using a concept of average damage to particular marine area. We also formulate the problem of oil spill risk control, when some accident parameters are not known, but their probability distribution is given. We propose a new algorithm to solve such problems and show results of our model simulations. The work can be interesting to broad environmental, physics and mathematics community. The work is supported by Russian Foundation for Basic Research grant 16-31-00510.
Integrated Guidance and Control of Homing Missiles Against Ground Fixed Targets
Institute of Scientific and Technical Information of China (English)
Hou Mingzhe; Duan Guangren
2008-01-01
This paper presents a scheme of integrated guidance and autopilot design for homing missiles against ground fixed targets. An in- tegrated guidance and control model in the pitch plane is formulated and further changed into a normal form by nonlinear coordinate transformation. By adopting the sliding mode control approach, an adaptive nonlinear control law of the system is designed so that the missile can hit the target accurately with a desired impact attitude angle. The stability analysis of the closed-loop system is also con- ducted. The numerical simulation has confirmed the usefulness of the proposed design scheme.
Munday, Cathy; Domagalski, Joseph L.
2003-01-01
Evaluating the extent that bias and variability affect the interpretation of ground- and surface-water data is necessary to meet the objectives of the National Water-Quality Assessment (NAWQA) Program. Quality-control samples used to evaluate the bias and variability include annual equipment blanks, field blanks, field matrix spikes, surrogates, and replicates. This report contains quality-control results for the constituents critical to the ground- and surface-water components of the Sacramento River Basin study unit of the NAWQA Program. A critical constituent is one that was detected frequently (more than 50 percent of the time in blank samples), was detected at amounts exceeding water-quality standards or goals, or was important for the interpretation of water-quality data. Quality-control samples were collected along with ground- and surface-water samples during the high intensity phase (cycle 1) of the Sacramento River Basin NAWQA beginning early in 1996 and ending in 1998. Ground-water field blanks indicated contamination of varying levels of significance when compared with concentrations detected in environmental ground-water samples for ammonia, dissolved organic carbon, aluminum, and copper. Concentrations of aluminum in surface-water field blanks were significant when compared with environmental samples. Field blank samples collected for pesticide and volatile organic compound analyses revealed no contamination in either ground- or surface-water samples that would effect the interpretation of environmental data, with the possible exception of the volatile organic compound trichloromethane (chloroform) in ground water. Replicate samples for ground water and surface water indicate that variability resulting from sample collection, processing, and analysis was generally low. Some of the larger maximum relative percentage differences calculated for replicate samples occurred between samples having lowest absolute concentration differences and(or) values near
Is ground cover vegetation an effective biological control enhancement strategy against olive pests?
Directory of Open Access Journals (Sweden)
Daniel Paredes
Full Text Available Ground cover vegetation is often added or allowed to generate to promote conservation biological control, especially in perennial crops. Nevertheless, there is inconsistent evidence of its effectiveness, with studies reporting positive, nil or negative effects on pest control. This might arise from differences between studies at the local scale (e.g. orchard management and land use history, the landscape context (e.g. presence of patches of natural or semi-natural vegetation near the focal orchard, or regional factors, particularly climate in the year of the study. Here we present the findings from a long-term regional monitoring program conducted on four pest species (Bactrocera oleae, Prays oleae, Euphyllura olivina, Saissetia oleae in 2,528 olive groves in Andalusia (Spain from 2006 to 2012. Generalized linear mixed effect models were used to analyze the effect of ground cover on different response variables related to pest abundance, while accounting for variability at the local, landscape and regional scales. There were small and inconsistent effects of ground cover on the abundance of pests whilst local, landscape and regional variability explained a large proportion of the variability in pest response variables. This highlights the importance of local and landscape-related variables in biological control and the potential effects that might emerge from their interaction with practices, such as groundcover vegetation, implemented to promote natural enemy activity. The study points to perennial vegetation close to the focal crop as a promising alternative strategy for conservation biological control that should receive more attention.
Is ground cover vegetation an effective biological control enhancement strategy against olive pests?
Paredes, Daniel; Cayuela, Luis; Gurr, Geoff M; Campos, Mercedes
2015-01-01
Ground cover vegetation is often added or allowed to generate to promote conservation biological control, especially in perennial crops. Nevertheless, there is inconsistent evidence of its effectiveness, with studies reporting positive, nil or negative effects on pest control. This might arise from differences between studies at the local scale (e.g. orchard management and land use history), the landscape context (e.g. presence of patches of natural or semi-natural vegetation near the focal orchard), or regional factors, particularly climate in the year of the study. Here we present the findings from a long-term regional monitoring program conducted on four pest species (Bactrocera oleae, Prays oleae, Euphyllura olivina, Saissetia oleae) in 2,528 olive groves in Andalusia (Spain) from 2006 to 2012. Generalized linear mixed effect models were used to analyze the effect of ground cover on different response variables related to pest abundance, while accounting for variability at the local, landscape and regional scales. There were small and inconsistent effects of ground cover on the abundance of pests whilst local, landscape and regional variability explained a large proportion of the variability in pest response variables. This highlights the importance of local and landscape-related variables in biological control and the potential effects that might emerge from their interaction with practices, such as groundcover vegetation, implemented to promote natural enemy activity. The study points to perennial vegetation close to the focal crop as a promising alternative strategy for conservation biological control that should receive more attention.
Algorithmic aspects of topology control problems for ad hoc networks
Energy Technology Data Exchange (ETDEWEB)
Liu, R. (Rui); Lloyd, E. L. (Errol L.); Marathe, M. V. (Madhav V.); Ramanathan, R. (Ram); Ravi, S. S.
2002-01-01
Topology control problems are concerned with the assignment of power values to nodes of an ad hoc network so that the power assignment leads to a graph topology satisfying some specified properties. This paper considers such problems under several optimization objectives, including minimizing the maximum power and minimizing the total power. A general approach leading to a polynomial algorithm is presented for minimizing maximum power for a class of graph properties, called monotone properties. The difficulty of generalizing the approach to properties that are not monoione is pointed out. Problems involving the minimization of total power are known to be NP-complete even for simple graph properties. A general approach that leads to an approximation algorithm for minimizing the total power for some monotone properties is presented. Using this approach, a new approximation algorithm for the problem of minimizing the total power for obtaining a 2-node-connected graph is obtained. It is shown that this algorithm provides a constant performance guarantee. Experimental results from an implementation of the approximation algorithm are also presented.
Olympio, Joris T
2011-01-01
The paper describes a continuous second-variation algorithm to solve optimal control problems where the control is defined on a closed set. A second order expansion of a Lagrangian provides linear updates of the control to construct a locally feedback optimal control of the problem. Since the process involves a backward and a forward stage, which require storing trajectories, a method has been devised to accurately store continuous solutions of ordinary differential equations. Thanks to the continuous approach, the method adapts implicitly the numerical time mesh. The novel method is demonstrated on bang-bang optimal control problems, showing the suitability of the method to identify automatically optimal switching points in the control.
On some inventory control problems with state-dependent parameters
Directory of Open Access Journals (Sweden)
Lev Abolnikov
1987-01-01
Full Text Available This article analyzes discrete Markov processes that arise in some general control problems of a storage (or a dam with an infinite capacity. Employing a special Ã‚Â“step-wiseÃ‚Â” structure of the transition matrices of these processes, the author obtains conditions for their ergodicity and develops an implementable algorithm for finding the generating function of the corresponding distributions. This algorithm is applied to a dam with a multilevel state-dependent control strategy, according to which parameters of the input and output processes may depend on the amount of the water in the dam. The method is illustrated with a case of a single-level control strategy where explicit results are obtained.
Günüşen, Neslihan Partlak; Serçekuş, Pınar; Edeer, Aylin Durmaz
2014-06-01
The purpose of this study is to compare the locus of control and problem-solving skills of nursing students studying with the problem-based learning method with those of nursing students studying with the traditional method. This is a descriptive and comparative study. For data collection, the Problem-Solving Skills Inventory and the Locus of Control Scale were used. The study sample included 680 nursing students. It was determined that the problem-based learning method was more effective in the development of problem-solving skills and internal locus of control than was the traditional method. © 2014 NANDA International.
Aguilar, Michael L.; Bonanne, Kevin H.; Favretto, Jeffrey A.; Jackson, Maddalena M.; Jones, Stephanie L.; Mackey, Ryan M.; Sarrel, Marc A.; Simpson, Kimberly A.
2014-01-01
The Exploration Systems Development (ESD) Standing Review Board (SRB) requested the NASA Engineering and Safety Center (NESC) conduct an independent review of the plan developed by Ground Systems Development and Operations (GSDO) for identifying models and emulators to create a tool(s) to verify their command and control software. The NESC was requested to identify any issues or weaknesses in the GSDO plan. This document contains the outcome of the NESC review.
Linear Riccati Dynamics, Constant Feedback, and Controllability in Linear Quadratic Control Problems
Ronald J. Balvers; Douglas W. Mitchell
2005-01-01
Conditions are derived for linear-quadratic control (LQC) problems to exhibit linear evolution of the Riccati matrix and constancy of the control feedback matrix. One of these conditions involves a matrix upon whose rank a necessary condition and a sufficient condition for controllability are based. Linearity of Riccati evolution allows for rapid iterative calculation, and constancy of the control feedback matrix allows for time-invariant comparative static analysis of policy reactions.
Institute of Scientific and Technical Information of China (English)
无
2009-01-01
The Chinese Area Positioning System (CAPS) works without atomic clocks on the satellite, and the CAPS navigation signals transmitted on the ground may achieve the same effect as that with high-performance atomic clocks on the satellite. The primary means of achieving that effect is through the time synchronization and carrier frequency control of the CAPS navigation signals generated on the ground. In this paper the synchronization requirements of different time signals are analyzed by the formation of navigation signals, and the theories and methods of the time synchronization of the CAPS navigation signals generated on the ground are also introduced. According to the conditions of the high-precision satellite velocitymeasurement signal source, the carrier frequency and its chains of the navigation signals are constructed. CAPS velocity measurement is realized by the expected deviation of real time control to the carrier frequency, and the precision degree of this method is also analyzed. The experimental results show that the time synchronization precision of CAPS generating signals is about 0.3 ns and the precision of the velocity measurement signal source is about 4 cm/s. This proves that the theories and methods of the generating time synchronization and carrier frequency control are workable.
Advanced Software Ground Station and UAV Development for NLoS Control Using Mobile Communications
Directory of Open Access Journals (Sweden)
Amr AbdElHamid
2015-01-01
Full Text Available Over the last decades, Unmanned Aerial Systems (UASs have gained much attention due to their various applications in different sections. However, their communication range is limited to utilized communication equipment. Therefore, utilization of GSM channels opens a new prospect towards long distance UAV missions and mobile command and control centers. This paper demonstrates new design and development of a small-scale UAV and a Ground Control Station (GCS using GSM bidirectional communications for Non-Line of Sight (NLoS long range control. GCSs are considered the front end node in UAV guidance process. Therefore, the proposed GCS employs a two-layer framework to consider all ground pilot requirements. Moreover, a new exploitation of global weather forecast data is added to the GCS. On the other hand, the proposed airborne system utilizes a new integration of different Commercial off-the-Shelf (COTS components and excludes short range receivers. The ground and flight tests show that stable bidirectional GSM communication is established, reliable hardware integration is accomplished, real time performance is achieved, GCS functional fidelity is obtained, and low cost is maintained. Finally, some qualitative aspects of the proposed platform are presented to address the detailed features.
Institute of Scientific and Technical Information of China (English)
WU HaiTao; BIAN YuJing; LU XiaoChun; LI XiaoHui; WANG DanNi
2009-01-01
The Chinese Area Positioning System (CAPS) works without atomic clocks on the satellite,and the CAPS navigation signals transmitted on the ground may achieve the same effect as that with high-performance atomic clocks on the satellite.The primary means of achieving that effect is through the time synchronization and carrier frequency control of the CAPS navigation signals generated on the ground.In this paper the synchronization requirements of different time signals are analyzed by the formation of navigation signals,and the theories and methods of the time synchronization of the CAPS navigation signals generated on the ground are also introduced.According to the conditions of the high-precision satellite velocity-measurement signal source,the carrier frequency and its chains of the navigation signals are constructed.CAPS velocity measurement is realized by the expected deviation of real time control to the carrier frequency,end the precision degree of this method is also analyzed.The experimental results show that the time synchronization precision of CAPS generating signals is about 0.3 ns and the precision of the velocity measurement signal source is about 4 cm/s.This proves that the theories and methods of the generating time synchronization and carrier frequency control are workable.
Hesselfeldt, Rasmus; Gyllenborg, Jesper; Steinmetz, Jacob; Do, Hien Quoc; Hejselbæk, Julie; Rasmussen, Lars S
2014-04-01
Helicopters are widely used for interhospital transfers of stroke patients, but the benefit is sparsely documented. We hypothesised that helicopter transport would reduce system delay to thrombolytic treatment at the regional stroke centre. In this prospective controlled observational study, we included patients referred to a stroke centre if their ground transport time exceeded 30 min, or they were transported by a secondarily dispatched, physician-staffed helicopter. The primary endpoint was time from telephone contact to triaging neurologist to arrival in the stroke centre. Secondary endpoints included modified Rankin Scale at 3 months, 30-day and 1-year mortality. A total of 330 patients were included; 265 with ground transport and 65 with helicopter, of which 87 (33%) and 22 (34%), received thrombolysis, respectively (p=0.88). Time from contact to triaging neurologist to arrival in the regional stroke centre was significantly shorter in the ground group (55 (34-85) vs 68 (40-85) min, pground group (67 (42-136) km) than in the helicopter group (83 (46-143) km) (pground and helicopter transport. We found significantly shorter time from contact to triaging neurologist to arrival in the regional stroke centre if stroke patients were transported by primarily dispatched ground ambulance compared with a secondarily dispatched helicopter.
THE CONTROL VARIATIONAL METHOD FOR ELASTIC CONTACT PROBLEMS
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Mircea Sofonea
2010-07-01
Full Text Available We consider a multivalued equation of the form Ay + F(y = fin a real Hilbert space, where A is a linear operator and F represents the (Clarke subdifferential of some function. We prove existence and uniqueness results of the solution by using the control variational method. The main idea in this method is to minimize the energy functional associated to the nonlinear equation by arguments of optimal control theory. Then we consider a general mathematical model describing the contact between a linearly elastic body and an obstacle which leads to a variational formulation as above, for the displacement field. We apply the abstract existence and uniqueness results to prove the unique weak solvability of the corresponding contact problem. Finally, we present examples of contact and friction laws for which our results work.
New attitude penalty functions for spacecraft optimal control problems
Energy Technology Data Exchange (ETDEWEB)
Schaub, H.; Junkins, J.L. [Texas A and M Univ., College Station, TX (United States). Dept. of Aerospace Engineering; Robinett, R.D. [Sandia National Labs., Albuquerque, NM (United States)
1996-03-01
A solution of a spacecraft optimal control problem, whose cost function relies on an attitude description, usually depends on the choice of attitude coordinates used. A problem could be solved using 3-2-1 Euler angles or using classical Rodriguez parameters and yield two different ``optimal`` solutions, unless the performance index in invariant with respect to the attitude coordinate choice. Another problem arising with many attitude coordinates is that they have no sense of when a body has tumbled beyond 180{degrees} from the reference attitude. In many such cases it would be easier (i.e. cost less) to let the body complete the revolution than to force it to reverse the rotation and return to the desired attitude. This paper develops a universal attitude penalty function g() whose value is independent of the attitude coordinates chosen to represent it. Furthermore, this function will achieve its maximum value only when a principal rotation of {plus_minus}180{degrees} from the target state is performed. This will implicitly permit the g() function to sense the shortest rotational distance back to the reference state. An attitude penalty function which depends on the Modified Rodriguez Parameters (MRP) will also be presented. These recently discovered MRPs are a non-singular three-parameter set which can describe any three-attitude. This MRP penalty function is simpler than the attitude coordinate independent g() function, but retains the useful property of avoiding lengthy principal rotations of more than {plus_minus}180{degrees}.
Takamura, Eduardo; Mangum, Kevin
2016-01-01
The National Aeronautics and Space Administration (NASA) invests millions of dollars in spacecraft and ground system development, and in mission operations in the pursuit of scientific knowledge of the universe. In recent years, NASA sent a probe to Mars to study the Red Planet's upper atmosphere, obtained high resolution images of Pluto, and it is currently preparing to find new exoplanets, rendezvous with an asteroid, and bring a sample of the asteroid back to Earth for analysis. The success of these missions is enabled by mission assurance. In turn, mission assurance is backed by information assurance. The information systems supporting NASA missions must be reliable as well as secure. NASA - like every other U.S. Federal Government agency - is required to manage the security of its information systems according to federal mandates, the most prominent being the Federal Information Security Management Act (FISMA) of 2002 and the legislative updates that followed it. Like the management of enterprise information technology (IT), federal information security management takes a "one-size fits all" approach for protecting IT systems. While this approach works for most organizations, it does not effectively translate into security of highly specialized systems such as those supporting NASA missions. These systems include command and control (C&C) systems, spacecraft and instrument simulators, and other elements comprising the ground segment. They must be carefully configured, monitored and maintained, sometimes for several years past the missions' initially planned life expectancy, to ensure the ground system is protected and remains operational without any compromise of its confidentiality, integrity and availability. Enterprise policies, processes, procedures and products, if not effectively tailored to meet mission requirements, may not offer the needed security for protecting the information system, and they may even become disruptive to mission operations
Directory of Open Access Journals (Sweden)
A. S. Koval
2010-01-01
Full Text Available The paper considers problems concerning electromechanical interaction in elevators with an adjustable asynchronous electric drive equipped with the vector control systems under direct torque control and direct torque control with pulse-width modulator. A mathematical description of electromechanical elevator system with due account of nonlinearity of the worm gear is given in the paper. The paper presents a simplified circuit design of a control system with a fuzzy speed controller. It has been established that the factor of electromechanical interaction in electromechanical system with the adjustable asynchronous electric drive and an fuzzy speed controller is within the range which corresponds to existence of the essential electromechanical interaction.
The Next Generation of Ground Operations Command and Control; Scripting in C Sharp and Visual Basic
Ritter, George; Pedoto, Ramon
2010-01-01
This slide presentation reviews the use of scripting languages in Ground Operations Command and Control. It describes the use of scripting languages in a historical context, the advantages and disadvantages of scripts. It describes the Enhanced and Redesigned Scripting (ERS) language, that was designed to combine the features of a scripting language and the graphical and IDE richness of a programming language with the utility of scripting languages. ERS uses the Microsoft Visual Studio programming environment and offers custom controls that enable an ERS developer to extend the Visual Basic and C sharp language interface with the Payload Operations Integration Center (POIC) telemetry and command system.
Interior noise control ground test studies for advanced turboprop aircraft applications
Simpson, Myles A.; Cannon, Mark R.; Burge, Paul L.; Boyd, Robert P.
1989-01-01
The measurement and analysis procedures are documented, and the results of interior noise control ground tests conducted on a DC-9 aircraft test section are summarized. The objectives of these tests were to study the fuselage response characteristics of treated and untreated aircraft with aft-mount advanced turboprop engines and to analyze the effectiveness of selected noise control treatments in reducing passenger cabin noise on these aircraft. The results of fuselage structural mode surveys, cabin cavity surveys and sound intensity surveys are presented. The performance of various structural and cabin sidewall treatments is assessed, based on measurements of the resulting interior noise levels under simulated advanced turboprop excitation.
Singularity problem of control moment gyro cluster with vibration isolators
Institute of Scientific and Technical Information of China (English)
Cui Yinghui; Zheng Gangtie
2016-01-01
As powerful torque amplification actuators, control moment gyros (CMGs) are often used in the attitude control of many state-of-the-art high resolution satellites. However, the distur-bance generated by the CMGs can not only reduce the attitude stability of a satellite but also dete-riorate the performance of optic payloads. Currently, CMG vibration isolators are widely used to target this problem. The isolators can affect the singularity of the CMG system as they are placed between the CMGs and the satellite bus and provide additional freedoms to the CMG system due to their flexibility. The formulation of the output torque of a CMG is studied first considering the dynamic imbalance of its spin rotor and then the deformation angle as a result of the isolator’s flex-ibility is calculated. With the additional freedoms, the influence of isolator on the singularity problem is studied and a new steering logic to escape from the singular states is proposed.
Optimal Control Approaches to the Aggregate Production Planning Problem
Directory of Open Access Journals (Sweden)
Yasser A. Davizón
2015-12-01
Full Text Available In the area of production planning and control, the aggregate production planning (APP problem represents a great challenge for decision makers in production-inventory systems. Tradeoff between inventory-capacity is known as the APP problem. To address it, static and dynamic models have been proposed, which in general have several shortcomings. It is the premise of this paper that the main drawback of these proposals is, that they do not take into account the dynamic nature of the APP. For this reason, we propose the use of an Optimal Control (OC formulation via the approach of energy-based and Hamiltonian-present value. The main contribution of this paper is the mathematical model which integrates a second order dynamical system coupled with a first order system, incorporating production rate, inventory level, and capacity as well with the associated cost by work force in the same formulation. Also, a novel result in relation with the Hamiltonian-present value in the OC formulation is that it reduces the inventory level compared with the pure energy based approach for APP. A set of simulations are provided which verifies the theoretical contribution of this work.
Ground Control Point - Wireless System Network for UAV-based environmental monitoring applications
Mejia-Aguilar, Abraham
2016-04-01
In recent years, Unmanned Aerial Vehicles (UAV) have seen widespread civil applications including usage for survey and monitoring services in areas such as agriculture, construction and civil engineering, private surveillance and reconnaissance services and cultural heritage management. Most aerial monitoring services require the integration of information acquired during the flight (such as imagery) with ground-based information (such as GPS information or others) for improved ground truth validation. For example, to obtain an accurate 3D and Digital Elevation Model based on aerial imagery, it is necessary to include ground-based information of coordinate points, which are normally acquired with surveying methods based on Global Position Systems (GPS). However, GPS surveys are very time consuming and especially for longer time series of monitoring data repeated GPS surveys are necessary. In order to improve speed of data collection and integration, this work presents an autonomous system based on Waspmote technologies build on single nodes interlinked in a Wireless Sensor Network (WSN) star-topology for ground based information collection and later integration with surveying data obtained by UAV. Nodes are designed to be visible from the air, to resist extreme weather conditions with low-power consumption. Besides, nodes are equipped with GPS as well as Inertial Measurement Unit (IMU), accelerometer, temperature and soil moisture sensors and thus provide significant advantages in a broad range of applications for environmental monitoring. For our purpose, the WSN transmits the environmental data with 3G/GPRS to a database on a regular time basis. This project provides a detailed case study and implementation of a Ground Control Point System Network for UAV-based vegetation monitoring of dry mountain grassland in the Matsch valley, Italy.
Precise Ground-In-the-Loop Orbit Control for Low Earth Observation Satellites
Arbinger, C.; D'Amico, S.; Eineder, M.
The growing interest in earth observation missions equipped with space-borne optical and synthetic aperture radar (SAR) sensors drives the accuracy requirements with respect to orbit determination and control. Especially SAR interferometry with its capability to resolve the velocity of on-ground objects (e.g. for traffic monitoring, ocean currents and glacier monitoring) and to determine highly precise digital elevation models is of significant interest for scientific applications. These goals may be achieved using along-track and repeat-pass interferometry with a satellite formation, based on the precise orbit control of one satellite with respect to the osculating trajectory of the second satellite. Such a control concept will be realized by the German TerraSAR-X mission, with an expected launch in 2006, using a virtual formation, where a single satellite will be controlled in a tight manner with respect to a predefined osculating reference trajectory. This is very challenging, since common orbit disturbances, like for close twin formations, do not cancel out in this scenario. The predefined trajectory in the TerraSAR-X case could also be the orbit of a second satellite. The paper describes the generation of such a virtual reference orbit, discusses the ground-in-the-loop control concept and presents results from a long-term simulation.
Barrett, Alexander M.; Balme, Matthew R.; Patel, Manish R.; Hagermann, Axel
2017-10-01
The area surrounding Lomonosov crater on Mars has a high density of seemingly organised boulder patterns. These form seemingly sorted polygons and stripes within kilometre scale blockfields, patches of boulder strewn ground which are common across the Martian high latitudes. Several hypotheses have been suggested to explain the formation of clastic patterned ground on Mars. It has been proposed that these structures could have formed through freeze-thaw sorting, or conversely by the interaction of boulders with underlying fracture polygons. In this investigation a series of sites were examined to evaluate whether boulder patterns appear to be controlled by the distribution of underlying fractures and test the fracture control hypotheses for their formation. It was decided to focus on this suite of mechanisms as they are characterised by a clear morphological relationship, namely the presence of an underlying fracture network which can easily be evaluated over a large area. It was found that in the majority of examples at these sites did not exhibit fracture control. Although fractures were present at many sites there were very few sites where the fracture network appeared to be controlling the boulder distribution. In general these were not the sites with the best examples of organization, suggesting that the fracture control mechanisms are not the dominant geomorphic process organising the boulders in this area.
Fracture control of ground water flow and water chemistry in a rock aquitard.
Eaton, Timothy T; Anderson, Mary P; Bradbury, Kenneth R
2007-01-01
There are few studies on the hydrogeology of sedimentary rock aquitards although they are important controls in regional ground water flow systems. We formulate and test a three-dimensional (3D) conceptual model of ground water flow and hydrochemistry in a fractured sedimentary rock aquitard to show that flow dynamics within the aquitard are more complex than previously believed. Similar conceptual models, based on regional observations and recently emerging principles of mechanical stratigraphy in heterogeneous sedimentary rocks, have previously been applied only to aquifers, but we show that they are potentially applicable to aquitards. The major elements of this conceptual model, which is based on detailed information from two sites in the Maquoketa Formation in southeastern Wisconsin, include orders of magnitude contrast between hydraulic diffusivity (K/S(s)) of fractured zones and relatively intact aquitard rock matrix, laterally extensive bedding-plane fracture zones extending over distances of over 10 km, very low vertical hydraulic conductivity of thick shale-rich intervals of the aquitard, and a vertical hydraulic head profile controlled by a lateral boundary at the aquitard subcrop, where numerous surface water bodies dominate the shallow aquifer system. Results from a 3D numerical flow model based on this conceptual model are consistent with field observations, which did not fit the typical conceptual model of strictly vertical flow through an aquitard. The 3D flow through an aquitard has implications for predicting ground water flow and for planning and protecting water supplies.
Dao, Arik-Quang V.; Martin, Lynne; Mohlenbrink, Christoph; Bienert, Nancy; Wolte, Cynthia; Gomez, Ashley; Claudatos, Lauren; Mercer, Joey
2017-01-01
The purpose of this paper is to report on a human factors evaluation of ground control station design concepts for interacting with an unmanned traffic management system. The data collected for this paper comes from recent field tests for NASA's Unmanned Traffic Management (UTM) project, and covers the following topics; workload, situation awareness, as well as flight crew communication, coordination, and procedures. The goal of this evaluation was to determine if the various software implementations for interacting with the UTM system can be described and classified into design concepts to provide guidance for the development of future UTM interfaces. We begin with a brief description of NASA's UTM project, followed by a description of the test range configuration related to a second development phase. We identified (post hoc) two classes in which the ground control stations could be grouped. This grouping was based on level of display integration. The analysis was exploratory and informal. It was conducted to compare ground stations across those two classes and against the aforementioned topics. Herein, we discuss the results.
Feedback Control Method Using Haar Wavelet Operational Matrices for Solving Optimal Control Problems
Waleeda Swaidan; Amran Hussin
2013-01-01
Most of the direct methods solve optimal control problems with nonlinear programming solver. In this paper we propose a novel feedback control method for solving for solving affine control system, with quadratic cost functional, which makes use of only linear systems. This method is a numerical technique, which is based on the combination of Haar wavelet collocation method and successive Generalized Hamilton-Jacobi-Bellman equation. We formulate some new Haar wavelet oper...
Energy Technology Data Exchange (ETDEWEB)
Cameron, S.M.; Stantz, K.M.; Trahan, M.W.; Wagner, J.S.
1998-11-01
Comprehensive management of the battle-space has created new requirements in information management, communication, and interoperability as they effect surveillance and situational awareness. The objective of this proposal is to expand intelligent controls theory to produce a uniquely powerful implementation of distributed ground-based measurement incorporating both local collective behavior, and interoperative global optimization for sensor fusion and mission oversight. By using a layered hierarchal control architecture to orchestrate adaptive reconfiguration of autonomous robotic agents, we can improve overall robustness and functionality in dynamic tactical environments without information bottlenecks. In this concept, each sensor is equipped with a miniaturized optical reflectance modulator which is interactively monitored as a remote transponder using a covert laser communication protocol from a remote mothership or operative. Robot data-sharing at the ground level can be leveraged with global evaluation criteria, including terrain overlays and remote imaging data. Information sharing and distributed intelli- gence opens up a new class of remote-sensing applications in which small single-function autono- mous observers at the local level can collectively optimize and measure large scale ground-level signals. AS the need for coverage and the number of agents grows to improve spatial resolution, cooperative behavior orchestrated by a global situational awareness umbrella will be an essential ingredient to offset increasing bandwidth requirements within the net. A system of the type described in this proposal will be capable of sensitively detecting, tracking, and mapping spatial distributions of measurement signatures which are non-stationary or obscured by clutter and inter- fering obstacles by virtue of adaptive reconfiguration. This methodology could be used, for example, to field an adaptive ground-penetrating radar for detection of underground structures in
Robust H∞ output-feedback control for path following of autonomous ground vehicles
Hu, Chuan; Jing, Hui; Wang, Rongrong; Yan, Fengjun; Chadli, Mohammed
2016-03-01
This paper presents a robust H∞ output-feedback control strategy for the path following of autonomous ground vehicles (AGVs). Considering the vehicle lateral velocity is usually hard to measure with low cost sensor, a robust H∞ static output-feedback controller based on the mixed genetic algorithms (GA)/linear matrix inequality (LMI) approach is proposed to realize the path following without the information of the lateral velocity. The proposed controller is robust to the parametric uncertainties and external disturbances, with the parameters including the tire cornering stiffness, vehicle longitudinal velocity, yaw rate and road curvature. Simulation results based on CarSim-Simulink joint platform using a high-fidelity and full-car model have verified the effectiveness of the proposed control approach.
Free boundary problems in controlled release pharmaceuticals: II. swelling-controlled release
Cohen, Donald S.; Erneux, Thomas
1988-01-01
A problem in controlled release pharmaceutical systems is formulated and studied. The device modeled is a polymer matrix containing an initially immobilized drug. The release of the drug is achieved by countercurrent diffusion through a penetrant solvent with the release rate being determined by the rate of diffusion of the solvent in the polymer. The mathematical theory yields a free boundary problem which is studied in various asymptotic regimes.
Solving Optimal Control Problems by Exploiting Inherent Dynamical Systems Structures
Flaßkamp, Kathrin; Ober-Blöbaum, Sina; Kobilarov, Marin
2012-08-01
Computing globally efficient solutions is a major challenge in optimal control of nonlinear dynamical systems. This work proposes a method combining local optimization and motion planning techniques based on exploiting inherent dynamical systems structures, such as symmetries and invariant manifolds. Prior to the optimal control, the dynamical system is analyzed for structural properties that can be used to compute pieces of trajectories that are stored in a motion planning library. In the context of mechanical systems, these motion planning candidates, termed primitives, are given by relative equilibria induced by symmetries and motions on stable or unstable manifolds of e.g. fixed points in the natural dynamics. The existence of controlled relative equilibria is studied through Lagrangian mechanics and symmetry reduction techniques. The proposed framework can be used to solve boundary value problems by performing a search in the space of sequences of motion primitives connected using optimized maneuvers. The optimal sequence can be used as an admissible initial guess for a post-optimization. The approach is illustrated by two numerical examples, the single and the double spherical pendula, which demonstrates its benefit compared to standard local optimization techniques.
Characterization of the Aerodynamic Ground Effect and Its Influence in Multirotor Control
National Research Council Canada - National Science Library
Pedro Sanchez-Cuevas; Guillermo Heredia; Anibal Ollero
2017-01-01
This paper analyzes the ground effect in multirotors, that is, the change in the thrust generated by the rotors when flying close to the ground due to the interaction of the rotor airflow with the ground surface...
Feedback Control Method Using Haar Wavelet Operational Matrices for Solving Optimal Control Problems
Directory of Open Access Journals (Sweden)
Waleeda Swaidan
2013-01-01
Full Text Available Most of the direct methods solve optimal control problems with nonlinear programming solver. In this paper we propose a novel feedback control method for solving for solving affine control system, with quadratic cost functional, which makes use of only linear systems. This method is a numerical technique, which is based on the combination of Haar wavelet collocation method and successive Generalized Hamilton-Jacobi-Bellman equation. We formulate some new Haar wavelet operational matrices in order to manipulate Haar wavelet series. The proposed method has been applied to solve linear and nonlinear optimal control problems with infinite time horizon. The simulation results indicate that the accuracy of the control and cost can be improved by increasing the wavelet resolution.
Using Model Checking for Analyzing Distributed Power Control Problems
Directory of Open Access Journals (Sweden)
Thomas Brihaye
2010-01-01
Full Text Available Model checking (MC is a formal verification technique which has been known and still knows a resounding success in the computer science community. Realizing that the distributed power control (PC problem can be modeled by a timed game between a given transmitter and its environment, the authors wanted to know whether this approach can be applied to distributed PC. It turns out that it can be applied successfully and allows one to analyze realistic scenarios including the case of discrete transmit powers and games with incomplete information. The proposed methodology is as follows. We state some objectives a transmitter-receiver pair would like to reach. The network is modeled by a game where transmitters are considered as timed automata interacting with each other. The objectives are then translated into timed alternating-time temporal logic formulae and MC is exploited to know whether the desired properties are verified and determine a winning strategy.
Diversity Controlling Genetic Algorithm for Order Acceptance and Scheduling Problem
Directory of Open Access Journals (Sweden)
Cheng Chen
2014-01-01
Full Text Available Selection and scheduling are an important topic in production systems. To tackle the order acceptance and scheduling problem on a single machine with release dates, tardiness penalty, and sequence-dependent setup times, in this paper a diversity controlling genetic algorithm (DCGA is proposed, in which a diversified population is maintained during the whole search process through survival selection considering both the fitness and the diversity of individuals. To measure the similarity between individuals, a modified Hamming distance without considering the unaccepted orders in the chromosome is adopted. The proposed DCGA was validated on 1500 benchmark instances with up to 100 orders. Compared with the state-of-the-art algorithms, the experimental results show that DCGA improves the solution quality obtained significantly, in terms of the deviation from upper bound.
Controls on coral-ground development along the northern Mesoamerican Reef tract.
Directory of Open Access Journals (Sweden)
Rosa E Rodríguez-Martínez
Full Text Available Coral-grounds are reef communities that colonize rocky substratum but do not form framework or three-dimensional reef structures. To investigate why, we used video transects and underwater photography to determine the composition, structure and status of a coral-ground community located on the edge of a rocky terrace in front of a tourist park, Xcaret, in the northern Mesoamerican Reef tract, Mexico. The community has a relatively low coral, gorgonian and sponge cover (40%. We recorded 23 species of Scleractinia, 14 species of Gorgonacea and 30 species of Porifera. The coral community is diverse but lacks large coral colonies, being dominated instead by small, sediment-tolerant, and brooding species. In these small colonies, the abundance of potentially lethal interactions and partial mortality is high but decreases when colonies are larger than 40 cm. Such characteristics are consistent with an environment control whereby storm waves periodically remove larger colonies and elevate sediment flux. The community only survives these storm conditions due to its slope-break location, which ensures lack of burial and continued local recruitment. A comparison with similar coral-ground communities in adjacent areas suggests that the narrow width of the rock terrace hinders sediment stabilization, thereby ensuring that communities cannot escape bottom effects and develop into three-dimensional reef structures on geological time scales.
Directory of Open Access Journals (Sweden)
Fitri Yakub
2016-01-01
Full Text Available We present a comparative study of model predictive control approaches of two-wheel steering, four-wheel steering, and a combination of two-wheel steering with direct yaw moment control manoeuvres for path-following control in autonomous car vehicle dynamics systems. Single-track mode, based on a linearized vehicle and tire model, is used. Based on a given trajectory, we drove the vehicle at low and high forward speeds and on low and high road friction surfaces for a double-lane change scenario in order to follow the desired trajectory as close as possible while rejecting the effects of wind gusts. We compared the controller based on both simple and complex bicycle models without and with the roll vehicle dynamics for different types of model predictive control manoeuvres. The simulation result showed that the model predictive control gave a better performance in terms of robustness for both forward speeds and road surface variation in autonomous path-following control. It also demonstrated that model predictive control is useful to maintain vehicle stability along the desired path and has an ability to eliminate the crosswind effect.
Energy Technology Data Exchange (ETDEWEB)
Luttrell, S.P.; Newcomer, D.R.; Teel, S.S.; Vermeul, V.R.
1992-11-01
The purpose of this study is to quantify ground-water and contaminant discharge to the Columbia River in the Hanford Townsite vicinity. The primary objectives of the work are to: describe the hydrogeologic setting and controls on ground-water movement and contaminant discharge to the Columbia River; understand the river/aquifer relationship and its effects on contaminant discharge to the Columbia River; quantify the ground-water and contaminant mass discharge to the Columbia River; and provide data that may be useful for a three-dimensional model of ground-water flow and contaminant transport in the Hanford Townsite study area. The majority of ground-water contamination occurs within the unconfined aquifer; therefore, ground-water and contaminant discharge from the unconfined aquifer is the emphasis of this study. The period of study is primarily from June 1990 through March 1992.
Flight validation of ground-based assessment for control power requirements at high angles of attack
Ogburn, Marilyn E.; Ross, Holly M.; Foster, John V.; Pahle, Joseph W.; Sternberg, Charles A.; Traven, Ricardo; Lackey, James B.; Abbott, Troy D.
1994-01-01
A review is presented in viewgraph format of an ongoing NASA/U.S. Navy study to determine control power requirements at high angles of attack for the next generation high-performance aircraft. This paper focuses on recent flight test activities using the NASA High Alpha Research Vehicle (HARV), which are intended to validate results of previous ground-based simulation studies. The purpose of this study is discussed, and the overall program structure, approach, and objectives are described. Results from two areas of investigation are presented: (1) nose-down control power requirements and (2) lateral-directional control power requirements. Selected results which illustrate issues and challenges that are being addressed in the study are discussed including test methodology, comparisons between simulation and flight, and general lessons learned.
Debbarma, Sanjoy; Saikia, Lalit Chandra; Sinha, Nidul
2014-03-01
Present work focused on automatic generation control (AGC) of a three unequal area thermal systems considering reheat turbines and appropriate generation rate constraints (GRC). A fractional order (FO) controller named as I(λ)D(µ) controller based on crone approximation is proposed for the first time as an appropriate technique to solve the multi-area AGC problem in power systems. A recently developed metaheuristic algorithm known as firefly algorithm (FA) is used for the simultaneous optimization of the gains and other parameters such as order of integrator (λ) and differentiator (μ) of I(λ)D(µ) controller and governor speed regulation parameters (R). The dynamic responses corresponding to optimized I(λ)D(µ) controller gains, λ, μ, and R are compared with that of classical integer order (IO) controllers such as I, PI and PID controllers. Simulation results show that the proposed I(λ)D(µ) controller provides more improved dynamic responses and outperforms the IO based classical controllers. Further, sensitivity analysis confirms the robustness of the so optimized I(λ)D(µ) controller to wide changes in system loading conditions and size and position of SLP. Proposed controller is also found to have performed well as compared to IO based controllers when SLP takes place simultaneously in any two areas or all the areas. Robustness of the proposed I(λ)D(µ) controller is also tested against system parameter variations.
He, Jia; Xu, You-Lin; Zhan, Sheng; Huang, Qin
2017-03-01
When health monitoring system and vibration control system both are required for a building structure, it will be beneficial and cost-effective to integrate these two systems together for creating a smart building structure. Recently, on the basis of extended Kalman filter (EKF), a time-domain integrated approach was proposed for the identification of structural parameters of the controlled buildings with unknown ground excitations. The identified physical parameters and structural state vectors were then utilized to determine the control force for vibration suppression. In this paper, the possibility of establishing such a smart building structure with the function of simultaneous damage detection and vibration suppression was explored experimentally. A five-story shear building structure equipped with three magneto-rheological (MR) dampers was built. Four additional columns were added to the building model, and several damage scenarios were then simulated by symmetrically cutting off these columns in certain stories. Two sets of earthquakes, i.e. Kobe earthquake and Northridge earthquake, were considered as seismic input and assumed to be unknown during the tests. The structural parameters and the unknown ground excitations were identified during the tests by using the proposed identification method with the measured control forces. Based on the identified structural parameters and system states, a switching control law was employed to adjust the current applied to the MR dampers for the purpose of vibration attenuation. The experimental results show that the presented approach is capable of satisfactorily identifying structural damages and unknown excitations on one hand and significantly mitigating the structural vibration on the other hand.
Form control in atmospheric pressure plasma processing of ground fused silica
Li, Duo; Wang, Bo; Xin, Qiang; Jin, Huiliang; Wang, Jun; Dong, Wenxia
2014-08-01
Atmospheric Pressure Plasma Processing (APPP) using inductively coupled plasma has demonstrated that it can achieve comparable removal rate on the optical surface of fused silica under the atmosphere pressure and has the advantage of inducing no sub-surface damage for its non-contact and chemical etching mechanism. APPP technology is a cost effective way, compared with traditional mechanical polishing, magnetorheological finishing and ion beam figuring. Thus, due to these advantages, this technology is being tested to fabricate large aperture optics of fused silica to help shorten the polishing time in optics fabrication chain. Now our group proposes to use inductively coupled plasma processing technology to fabricate ground surface of fused silica directly after the grinding stage. In this paper, form control method and several processing parameters are investigated to evaluate the removal efficiency and the surface quality, including the robustness of removal function, velocity control mode and tool path strategy. However, because of the high heat flux of inductively coupled plasma, the removal depth with time can be non-linear and the ground surface evolvement will be affected. The heat polishing phenomenon is founded. The value of surface roughness is reduced greatly, which is very helpful to reduce the time of follow-up mechanical polishing. Finally, conformal and deterministic polishing experiments are analyzed and discussed. The form error is less 3%, before and after the APPP, when 10μm depth of uniform removal is achieved on a 60×60mm ground fused silica. Also, a basin feature is fabricated to demonstrate the figuring capability and stability. Thus, APPP is a promising technology in processing the large aperture optics.
Villalobos, Jorge; Flores, Salvador; Liedo, Pablo; Malo, Edi A
2017-10-01
Anastrepha fruit flies are considered one of the main phytosanitary problems for the fresh fruit industry in the USA, Caribbean islands and Latin America. Since 1994, the Mexican government has implemented the National Fruit Fly Program using an area-wide integrated pest management approach. In this paper, we evaluate the effectiveness of mass trapping and compare it with ground GF-120 spraying against Anastrepha obliqua and Anastrepha ludens populations in mango cv. Ataulfo orchards. Multilure® traps baited with Ceratrap® or Biolure® captured significantly more fruit flies than Captor 300 in field cage tests. Mass trapping and ground GF-120 spray significantly suppressed fruit fly populations compared with untreated plots. In Multilure traps placed in untreated plots, we captured significantly more fruit flies than in treated plots with mass trapping or GF-120 sprays. Plots treated with either mass trapping or GF-120 sprays reduced the percentage of infested fruit significantly compared with untreated plots. There was no difference between mass trapping and GF-120 ground bait spraying. Our results demonstrate that mass trapping was as effective as GF-120 ground spraying for the control of fruit flies in mango cv. Ataulfo orchards. The suppression effect of mass trapping was similar to GF-120 ground bait spraying. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.
Mathematical Problems in the Control of Underactuated Systems
Auckly, David; Kapitanski, Lev
1999-01-01
In this paper we will discuss problems and techniques related to underactuated systems. We give a mathematical formulation of several problems arising from applications, review some standard and new techniques, and pose some interesting and challenging open questions.
Reconstructing 3D coastal cliffs from airborne oblique photographs without ground control points
Dewez, T. J. B.
2014-05-01
Coastal cliff collapse hazard assessment requires measuring cliff face topography at regular intervals. Terrestrial laser scanner techniques have proven useful so far but are expensive to use either through purchasing the equipment or through survey subcontracting. In addition, terrestrial laser surveys take time which is sometimes incompatible with the time during with the beach is accessible at low-tide. By comparison, structure from motion techniques (SFM) are much less costly to implement, and if airborne, acquisition of several kilometers of coastline can be done in a matter of minutes. In this paper, the potential of GPS-tagged oblique airborne photographs and SFM techniques is examined to reconstruct chalk cliff dense 3D point clouds without Ground Control Points (GCP). The focus is put on comparing the relative 3D point of views reconstructed by Visual SFM with their synchronous Solmeta Geotagger Pro2 GPS locations using robust estimators. With a set of 568 oblique photos, shot from the open door of an airplane with a triplet of synchronized Nikon D7000, GPS and SFM-determined view point coordinates converge to X: ±31.5 m; Y: ±39.7 m; Z: ±13.0 m (LE66). Uncertainty in GPS position affects the model scale, angular attitude of the reference frame (the shoreline ends up tilted by 2°) and absolute positioning. Ground Control Points cannot be avoided to orient such models.
Validation of space/ground antenna control algorithms using a computer-aided design tool
Gantenbein, Rex E.
1995-01-01
The validation of the algorithms for controlling the space-to-ground antenna subsystem for Space Station Alpha is an important step in assuring reliable communications. These algorithms have been developed and tested using a simulation environment based on a computer-aided design tool that can provide a time-based execution framework with variable environmental parameters. Our work this summer has involved the exploration of this environment and the documentation of the procedures used to validate these algorithms. We have installed a variety of tools in a laboratory of the Tracking and Communications division for reproducing the simulation experiments carried out on these algorithms to verify that they do meet their requirements for controlling the antenna systems. In this report, we describe the processes used in these simulations and our work in validating the tests used.
Pseudospectral Collocation Methods for the Direct Transcription of Optimal Control Problems
2003-04-01
solving optimal control problems for trajectory optimization, spacecraft attitude control, jet thruster control, missile guidance and many other... optimal control problems using a pseudospectral direct transcription method. These problems are stated here so that they may be referred to elsewhere...e.g., [7]. 2.3 Prototypical Examples Throughout this thesis two example problems are used to demonstrate various prop- erties associated with solving
Discrete Time McKean–Vlasov Control Problem: A Dynamic Programming Approach
Energy Technology Data Exchange (ETDEWEB)
Pham, Huyên, E-mail: pham@math.univ-paris-diderot.fr; Wei, Xiaoli, E-mail: tyswxl@gmail.com [Laboratoire de Probabilités et Modèles Aléatoires, CNRS, UMR 7599, Université Paris Diderot (France)
2016-12-15
We consider the stochastic optimal control problem of nonlinear mean-field systems in discrete time. We reformulate the problem into a deterministic control problem with marginal distribution as controlled state variable, and prove that dynamic programming principle holds in its general form. We apply our method for solving explicitly the mean-variance portfolio selection and the multivariate linear-quadratic McKean–Vlasov control problem.
ORGANIZATIONAL AND ECONOMIC MODELING IN SOLVING PROBLEMS OF CONTROLLING
Directory of Open Access Journals (Sweden)
Kulikova S. Y.
2016-04-01
Full Text Available At the Department of "Economics and organization of production" at the end of XX - beginning of XXI centuries created the scientific school in the field of organizational and economic modeling, econometrics and statistics. The same name section of the department oversees the teaching of the relevant disciplines. The Laboratory of economic and mathematical methods in controlling of the Research and Education Center "Controlling and innovation in management" of Bauman Moscow State Technical University conducts research in this domain. This article is devoted to the activities of the scientific school, conducting research, and some of the results. We start with a discussion of the definitions of terms, which we use. Organizationaleconomic modeling - scientific, practical and academic discipline which devoted to the development, research and application of mathematical and statistical methods and models in economics and management of the national economy, especially in economics and management of industrial enterprises and their associations. The term "economic-mathematical methods and models" has close content. Statistical methods in economics - the subject of econometrics, the base of which is applied statistics. Organizational-economic modeling and econometrics are discussed as a theoretical and practical trainings and discipline. We developed textbooks and manuals on the organizational and economic modeling, econometrics and statistics. We have conducted theoretical research and development of applications in the field of organizational and economic modeling. In particular, the prediction is regarded as one of the management functions in industry. We study the problem of stability in the models and methods of development of strategy of the enterprise. For prospective organizational and economic mechanisms of management of industrial and economic activities, we proposed design based on solidary information economy
Botrytis cinerea Control and the Problem of Fungicide Resistance
Directory of Open Access Journals (Sweden)
Brankica Tanović
2011-01-01
Full Text Available Botrytis cinerea, the causal agent of grey mould, greatly affects fruit, grapevine, vegetable and ornamental crops production. It is a common causal agent of diseases in plants grown in protected areas, as well as fruit decay during storage and transport. The fungusinvades almost all parts of the plant in all developmental stages, and the symptoms are usually described as grey mould, grey mildew, brown rot and seedling blight. The paper reviews the current knowledge on control possibilities of this necrotrophic pathogen. Theattention is particularly paid to the mode of action of novel fungicides and to the problem of resistance. It is pointed out that by limiting the number of treatments in the growing season, avoiding the use of only one fungicide with a high risk for resistance development,appropriate application rate and timing, using mixtures of pesticides with different modes of action, as well as by alternative use of pesticides from different resistance groups, a longterm preservation of pesticide efficacy is provided.
Integrating care for neurodevelopmental disorders by unpacking control: A grounded theory study
Waxegård, Gustaf; Thulesius, Hans
2016-01-01
Background To establish integrated healthcare pathways for patients with neurodevelopmental disorders (ND) such as autism spectrum disorder and attention-deficit hyperactivity disorder is challenging. This study sets out to investigate the main concerns for healthcare professionals when integrating ND care pathways and how they resolve these concerns. Methods Using classic grounded theory (Glaser), we analysed efforts to improve and integrate an ND care pathway for children and youth in a Swedish region over a period of 6 years. Data from 42 individual interviews with a range of ND professionals, nine group interviews with healthcare teams, participant observation, a 2-day dialogue conference, focus group meetings, regional media coverage, and reports from other Swedish regional ND projects were analysed. Results The main concern for participants was to deal with overwhelming ND complexity by unpacking control, which is control over strategies to define patients’ status and needs. Unpacking control is key to the professionals’ strivings to expand constructive life space for patients, to squeeze health care to reach available care goals, to promote professional ideologies, and to uphold workplace integrity. Control-seeking behaviour in relation to ND unpacking is ubiquitous and complicates integration of ND care pathways. Conclusions The Unpacking control theory expands central aspects of professions theory and may help to improve ND care development. PMID:27609793
Integrating care for neurodevelopmental disorders by unpacking control: A grounded theory study
Directory of Open Access Journals (Sweden)
Gustaf Waxegård
2016-09-01
Full Text Available Background: To establish integrated healthcare pathways for patients with neurodevelopmental disorders (ND such as autism spectrum disorder and attention-deficit hyperactivity disorder is challenging. This study sets out to investigate the main concerns for healthcare professionals when integrating ND care pathways and how they resolve these concerns. Methods: Using classic grounded theory (Glaser, we analysed efforts to improve and integrate an ND care pathway for children and youth in a Swedish region over a period of 6 years. Data from 42 individual interviews with a range of ND professionals, nine group interviews with healthcare teams, participant observation, a 2-day dialogue conference, focus group meetings, regional media coverage, and reports from other Swedish regional ND projects were analysed. Results: The main concern for participants was to deal with overwhelming ND complexity by unpacking control, which is control over strategies to define patients’ status and needs. Unpacking control is key to the professionals’ strivings to expand constructive life space for patients, to squeeze health care to reach available care goals, to promote professional ideologies, and to uphold workplace integrity. Control-seeking behaviour in relation to ND unpacking is ubiquitous and complicates integration of ND care pathways. Conclusions: The Unpacking control theory expands central aspects of professions theory and may help to improve ND care development.
Whitfield, J D; Biamonte, J D
2012-01-01
Designing and optimizing cost functions and energy landscapes is a problem encountered in many fields of science and engineering. These landscapes and cost functions can be embedded and annealed in experimentally controllable spin Hamiltonians. Using an approach based on group theory and symmetries, we examine the embedding of Boolean logic gates into the ground state subspace of such spin systems. We describe parameterized families of diagonal Hamiltonians and symmetry operations which preserve the ground state subspace encoding the truth tables of Boolean formulas. The ground state embeddings of adder circuits are used to illustrate how gates are combined and simplified using symmetry. Our work is relevant for experimental demonstrations of ground state embeddings found in both classical optimization as well as adiabatic quantum optimization.
Han, Lanshan; Camlibel, M. Kanat; Pang, Jong-Shi; Heemels, W. P. Maurice H.
2012-01-01
This paper presents a numerical scheme for solving the continuous-time convex linear-quadratic (LQ) optimal control problem with mixed polyhedral state and control constraints. Unifying a discretization of this optimal control problem as often employed in model predictive control and that obtained
Optimal Control Problem of Feeding Adaptations of Daphnia and Neural Network Simulation
Kmet', Tibor; Kmet'ov, Mria
2010-09-01
A neural network based optimal control synthesis is presented for solving optimal control problems with control and state constraints and open final time. The optimal control problem is transcribed into nonlinear programming problem, which is implemented with adaptive critic neural network [9] and recurrent neural network for solving nonlinear proprojection equations [10]. The proposed simulation methods is illustrated by the optimal control problem of feeding adaptation of filter feeders of Daphnia. Results show that adaptive critic based systematic approach and neural network solving of nonlinear equations hold promise for obtaining the optimal control with control and state constraints and open final time.
Existence of Solutions of a Riccati Differential System from a General Cumulant Control Problem
Directory of Open Access Journals (Sweden)
Stanley R. Liberty
2011-01-01
Full Text Available We study a system of infinitely many Riccati equations that arise from a cumulant control problem, which is a generalization of regulator problems, risk-sensitive controls, minimal cost variance controls, and k-cumulant controls. We obtain estimates for the existence intervals of solutions of the system. In particular, new existence conditions are derived for solutions on the horizon of the cumulant control problem.
Chiang, Kai-Wei; Tsai, Meng-Lun; Chu, Chien-Hsun
2012-01-01
To facilitate applications such as environment detection or disaster monitoring, the development of rapid low cost systems for collecting near real time spatial information is very critical. Rapid spatial information collection has become an emerging trend for remote sensing and mapping applications. In this study, a fixed-wing Unmanned Aerial Vehicle (UAV)-based spatial information acquisition platform that can operate in Ground Control Point (GCP) free environments is developed and evaluated. The proposed UAV based photogrammetric platform has a Direct Georeferencing (DG) module that includes a low cost Micro Electro Mechanical Systems (MEMS) Inertial Navigation System (INS)/Global Positioning System (GPS) integrated system. The DG module is able to provide GPS single frequency carrier phase measurements for differential processing to obtain sufficient positioning accuracy. All necessary calibration procedures are implemented. Ultimately, a flight test is performed to verify the positioning accuracy in DG mode without using GCPs. The preliminary results of positioning accuracy in DG mode illustrate that horizontal positioning accuracies in the x and y axes are around 5 m at 300 m flight height above the ground. The positioning accuracy of the z axis is below 10 m. Therefore, the proposed platform is relatively safe and inexpensive for collecting critical spatial information for urgent response such as disaster relief and assessment applications where GCPs are not available.
Directory of Open Access Journals (Sweden)
Chien-Hsun Chu
2012-07-01
Full Text Available To facilitate applications such as environment detection or disaster monitoring, the development of rapid low cost systems for collecting near real time spatial information is very critical. Rapid spatial information collection has become an emerging trend for remote sensing and mapping applications. In this study, a fixed-wing Unmanned Aerial Vehicle (UAV-based spatial information acquisition platform that can operate in Ground Control Point (GCP free environments is developed and evaluated. The proposed UAV based photogrammetric platform has a Direct Georeferencing (DG module that includes a low cost Micro Electro Mechanical Systems (MEMS Inertial Navigation System (INS/ Global Positioning System (GPS integrated system. The DG module is able to provide GPS single frequency carrier phase measurements for differential processing to obtain sufficient positioning accuracy. All necessary calibration procedures are implemented. Ultimately, a flight test is performed to verify the positioning accuracy in DG mode without using GCPs. The preliminary results of positioning accuracy in DG mode illustrate that horizontal positioning accuracies in the x and y axes are around 5 m at 300 m flight height above the ground. The positioning accuracy of the z axis is below 10 m. Therefore, the proposed platform is relatively safe and inexpensive for collecting critical spatial information for urgent response such as disaster relief and assessment applications where GCPs are not available.
Tug fleet and ground operations schedules and controls. Volume 1: Executive summary
1975-01-01
This study presents Tug Fleet and Ground Operations Schedules and Controls plan. This plan was developed and optimized out of a combination of individual Tug program phased subplans, special emphasis studies, contingency analyses and sensitivity analyses. The subplans cover the Tug program phases: (1) Tug operational, (2) Interim Upper Stage (IUS)/Tug fleet utilization, (3) and IUS/Tug payload integration, (4) Tug site activation, (5) IUS/Tug transition, (6) Tug acquisition. Resource requirements (facility, GSE, TSE, software, manpower, logistics) are provided in each subplan, as are appropriate Tug processing flows, active and total IUS and Tug fleet requirements, fleet management and Tug payload integration concepts, facility selection recommendations, site activation and IUS to Tug transition requirements. The impact of operational concepts on Tug acquisition is assessed and the impact of operating Tugs out of KSC and WTR is analyzed and presented showing WTR as a delta. Finally, cost estimates for fleet management and ground operations of the DDT&E and operational phases of the Tug program are given.
Sediment problems in reservoirs. Control of sediment deposits
Energy Technology Data Exchange (ETDEWEB)
Jacobsen, Tom
1997-12-31
When a reservoir is formed on a river, sediment will deposit in the reservoir. Such processes are unfortunate, for instance, for the implementation of hydroelectric energy. This thesis studies the problem of reservoir sedimentation and discusses methods of removing the sediments. Various aspects of reservoir sedimentation are discussed. Anthropogenic impacts seem to greatly affect the erosion processes. Temporal distribution is uneven, mainly because of the very large flood events. A world map showing the Reservoir Capacity: Annual Sediment Inflow ratio for reservoirs with volume equal to 10% of annual inflow has been prepared. The map shows that sedimentation is severe in the western parts of North and South America, eastern, southern and northern Africa, parts of Australia and most of Asia. The development of medium-sized reservoirs is difficult, as they are too large for conventional flushing technique and too small to store the sediment that accumulates during their economic lifetime. A computer model, SSIIM, was used with good results in a case study of two flood drawdown trials in Lake Roxburg, New Zealand. Two techniques have been developed that permits controlled suction of sediment and water into a pipe: the Slotted Pipe Sediment Sluicer (SPSS) and the Saxophone Sediment Sluicer (SSS). The techniques exploit the inflow pattern in through a slot in a pipe. An equation describing this inflow pattern was derived and verified experimentally. The SPSS is fixed near the reservoir bed, and sediment that deposits on top of it is removed in the sluicing process. The SSS sluices sediment from the surface of the sediment deposits. Some technical and economic conditions affecting the economics of sediment removal from reservoirs have been identified and studied. 79 refs., 112 figs., 14 tabs.
Optimal control of the initiation of a pericyclic reaction in the electronic ground state
Indian Academy of Sciences (India)
Timm Bredtmann; Jörn Manz
2012-01-01
Pericyclic reactions in the electronic ground state may be initiated by down-chirped pump-dump sub-pulses of an optimal laser pulse, in the ultraviolet (UV) frequency and sub-10 femtosecond (fs) time domain. This is demonstrated by means of a quantum dynamics model simulation of the Cope rearrangement of Semibullvalene. The laser pulse is designed by means of optimal control theory, with detailed analysis of the mechanism. The theoretical results support the recent experimental initiation of a pericyclic reaction. The present approach provides an important step towards monitoring asynchronous electronic fluxes during synchronous nuclear pericyclic reaction dynamics, with femto-to-attosecond time resolution, as motivated by the recent prediction of our group.
Lampris, Christos; Stegemann, Julia A; Cheeseman, Christopher R
2008-11-01
Ground granulated blast furnace slag (ggbs) has been used to solidify air pollution control (APC) residues obtained from a major UK energy-from-waste plant. Samples were prepared with ggbs additions between 10 and 50 wt% of total dry mass and water/solids ratios between 0.35 and 0.80. Consistence, setting time, compressive strength and leaching characteristics have been investigated. Results indicated that the highly alkaline nature of APC residues due to the presence of free lime can be used to activate ggbs hydration reactions. Increasing ggbs additions and reducing the water content resulted in increased compressive strengths, with 50 wt% ggbs samples having average 28 d strengths of 20.6 MPa. Leaching tests indicate low physical encapsulation and minimal chemical fixation of chloride in ggbs solidified APC residues. The results suggest that more than 50 wt% ggbs additions would be required to treat APC residues to meet the current waste acceptance criteria limits for chloride.
Controlled disposal of domestic effluent sewage in the ground to reduce fecal coliforms
Directory of Open Access Journals (Sweden)
Paulo Fortes Neto
2008-12-01
Full Text Available The indiscriminate launching in water bodies of domestic sewage without treatment, or even treated, but without appropriate disinfection, contributes with significant amount of organisms of the called "coliform group” that can carry specific illnesses agents propagated through the water. The application of effluent in the ground, instead of direct disposal in water courses, in addition to being an alternative way for the disposal of residues and biological control of pollutants, constitutes an adequate way of nutrients supply to the soil and plants. So, this work had as objective the evaluation of the reduction of fecal coliforms, after controlled applications of 60 days treated effluent in cultivated soil, by analyzing the increase of fluorescent rhizobacterias Pseudomonas fluorescens and Bacillus spp. present in the rhizospheres of different crops. The experiment was developed in field conditions in the Experimental Farm of Department of Agrarian Sciences of the University of Taubaté, municipality of Taubaté, SP. The Experimental design consisted of random blocks, with five treatments including annual crops (Oats, Barley, Triticale - a cross between wheat and rye, Black Beans and non-cultivated soil as witness - blank reference and four repetitions, totalizing 20 ground plots with area of 2 m x 1 m with 50 cm space among plots on a Dystrophic Red-Yellow Latossol. Results from the microbial analyses of rhizosphere and non-rhizosphere soil indicated that the rhizosphere of oats had denser rhizobacterias than the other crops. However, the greatest efficiency was found in the reduction of thermo-tolerant coliforms for both black beans and non-cultivated soil.
Sfm_georef: Automating image measurement of ground control points for SfM-based projects
James, Mike R.
2016-04-01
Deriving accurate DEM and orthomosaic image products from UAV surveys generally involves the use of multiple ground control points (GCPs). Here, we demonstrate the automated collection of GCP image measurements for SfM-MVS processed projects, using sfm_georef software (James & Robson, 2012; http://www.lancaster.ac.uk/staff/jamesm/software/sfm_georef.htm). Sfm_georef was originally written to provide geo-referencing procedures for SfM-MVS projects. It has now been upgraded with a 3-D patch-based matching routine suitable for automating GCP image measurement in both aerial and ground-based (oblique) projects, with the aim of reducing the time required for accurate geo-referencing. Sfm_georef is compatible with a range of SfM-MVS software and imports the relevant files that describe the image network, including camera models and tie points. 3-D survey measurements of ground control are then provided, either for natural features or artificial targets distributed over the project area. Automated GCP image measurement is manually initiated through identifying a GCP position in an image by mouse click; the GCP is then represented by a square planar patch in 3-D, textured from the image and oriented parallel to the local topographic surface (as defined by the 3-D positions of nearby tie points). Other images are then automatically examined by projecting the patch into the images (to account for differences in viewing geometry) and carrying out a sub-pixel normalised cross-correlation search in the local area. With two or more observations of a GCP, its 3-D co-ordinates are then derived by ray intersection. With the 3-D positions of three or more GCPs identified, an initial geo-referencing transform can be derived to relate the SfM-MVS co-ordinate system to that of the GCPs. Then, if GCPs are symmetric and identical, image texture from one representative GCP can be used to search automatically for all others throughout the image set. Finally, the GCP observations can be
Fuzzy Self-Organising Control Of A Pendulum Problem
DEFF Research Database (Denmark)
Olivares, Manuel; Jantzen, Jan
1999-01-01
In a cart-ball balancer the control objective is to balance a ball on a curved track. This simulation study in Simulink tries to stabilise the system with a nonlinear adaptive controller. A simplified adjustment mechanism is implemented, and test results show that the adjustment mechanism works......, if it is applied to the cart controller, but fails to work on the ball controller....
Application of Adaptive Techniques to Problems in Control and Communication.
1982-01-01
IEEE Transactions on Automatic Control in 1982. (2...signals in the adaptive system. These results will appear in the IEEE Transactions on Automatic Control . A brief comparison of the two schemes described...Model Reference Adaptive Control in the Presence of Bounded Disturbances" S&IS Report No. 8103, March 1981 (to appear in IEEE Transactions on Automatic Control )
Bladder Control Problems in Women: Lifestyle Strategies for Relief
... lemons and limes — and fruit juices, spicy foods, tomato-based products, carbonated drinks, artificial sweeteners, corn syrup, ... problems can make constipation worse. Exercising, drinking enough water and ... stress urinary incontinence. National Association for Continence. http://www. ...
Methods of centers and methods of feasible directions for the solution of optimal control problems.
Polak, E.; Mukai, H.; Pironneau, O.
1971-01-01
Demonstration of the applicability of methods of centers and of methods of feasible directions to optimal control problems. Presented experimental results show that extensions of Frank-Wolfe (1956), Zoutendijk (1960), and Pironneau-Polak (1971) algorithms for nonlinear programming problems can be quite efficient in solving optimal control problems.
The problem of determining the range of innovation controlling functions
Directory of Open Access Journals (Sweden)
N.M. Mykhaylychenko
2012-03-01
Full Text Available The article analyzes the concept of controlling of innovation, examines the various approaches to defining the range of functions of innovation controlling subsystem and determines its place in the system of company controlling and the management system as a whole. It provides the authors definition of controlling of innovation, defines the circle of functions to be performed by controlling of innovation the coordination, analytical, methodical functions and the function of information management of innovation processes in the enterprise.
A Transformation Approach to Optimal Control Problems with Bounded State Variables
Hanafy, Lawrence Hanafy
1971-01-01
A technique is described and utilized in the study of the solutions to various general problems in optimal control theory, which are converted in to Lagrange problems in the calculus of variations. This is accomplished by mapping certain properties in Euclidean space onto closed control and state regions. Nonlinear control problems with a unit m cube as control region and unit n cube as state region are considered.
Directory of Open Access Journals (Sweden)
Russel J Stonier
2003-08-01
Full Text Available In this paper we examine the application of evolutionary algorithms to find open-loop control solutions of the optimal control problem arising from the semidiscretisation of a linear parabolic tracking problem with boundary control. The solution is compared with the solutions obtained by methods based upon the variational equations of the Minimum Principle and the finite element method.
Directory of Open Access Journals (Sweden)
Maria eHuber
2015-07-01
Full Text Available The aims of the present multi-center study were to investigate the extent of mental health problems in adolescents with a hearing loss and cochlear implants (CIs in comparison to normal hearing (NH peers and to investigate possible relations between the extent of mental health problems of young CI users and hearing variables, such as age at implantation, or functional gain of CI. The survey included 140 adolescents with CI (mean age = 14.7, SD = 1.5 years and 140 NH adolescents (mean age = 14.8, SD = 1.4 years, their parents and teachers. Participants were matched by age, gender and social background. Within the CI group, 35 adolescents were identified as risk cases due to possible and manifest additional handicaps, and 11 adolescents were non-classifiable. Mental health problems were assessed with the Strengths and Difficulties Questionnaire (SDQ in the versions Self, Parent, and Teacher. The CI group showed significantly more Peer Problems than the NH group. When the CI group was split into a risk-group (35 risk cases and 11 non-classifiable persons and a non-risk group (n = 94, increased peer problems were perceived in both CI subgroups by adolescents themselves. However, no further differences between the CI non-risk group and the NH group were observed in any rater. The CI-risk group showed significantly more hyperactivity compared to the NH group and more hyperactivity and conduct problems compared to the CI non-risk group. Cluster analyses confirmed that there were significantly more adolescents with high problems in the CI-risk group compared to the CI non-risk group and the NH group. Adolescents with CI, who were able to understand speech in noise had significantly less difficulties compared to constricted CI users. Parents, teachers, and clinicians should be aware that CI users with additionally special needs may have mental health problems. However, peer problems were also experienced by CI adolescents without additional handicaps
Nakayama, Tomoko; Takayama, Yoshihisa; Fujikawa, Chiemi; Kodate, Kashiko
2016-08-01
To improve the quality of ground to satellite laser communications, we propose an optical duplicate system of the optical ground station. Our proposed approach can be used to control the beam irradiation area for a satellite position without changing the total power of the output beam and the mechanical drive unit; this is performed by controlling the input pattern of a liquid crystal filter inserted in the input plane of the optical duplicate system. Most of the power of the diffracted laser beam emitted from the ground is focused on the optical axis. By distributing the power to side lobes, it is possible to extend the coverage area for a satellite position. This system allows the laser beam irradiation area to be controlled by a sufficient degree by adjusting the threshold of the satellite reception level. We verify the efficacy of the system using wave optics numerical calculations.
A REVIEW OF INTELLIGENT CONTROL SYSTEMS APPLIED TO THE INVERTED-PENDULUM PROBLEM
Directory of Open Access Journals (Sweden)
Pedro Ponce
2014-01-01
Full Text Available This study shows the latest advances in the application of intelligent control to the inverted-pendulum problem. A complete review regarding intelligent control design is presented in this study in order to show the most important artificial intelligence methods used for controlling an Inverted-Pendulum. Also this study proposed the use of a neural-fuzzy-with-genetic-algorithms controller for the inverted pendulum problem which gives good results. Conventional controllers are presented in order to observe implementation problems. The study goes deeply in the details that have to take into account in order to understand design problems and limitations.
Optimal Control Problem Governed by Semilinear Parabolic Equation and its Algorithm
Institute of Scientific and Technical Information of China (English)
Chun-fa Li; Xue Yang; En-min Feng
2008-01-01
In this paper, an optimal control problem governed by semilinear parabolic equation which involves the control variable acting on forcing term and coefficients appearing in the higher order derivative terms is formulated and analyzed. The strong variation method, due originally to Mayne et al to solve the optimal control problem of a lumped parameter system, is extended to solve an optimal control problem governed by semilinear parabolic equation, a necessary condition is obtained, the strong variation algorithm for this optimal control problem is presented, and the corresponding convergence result of the algorithm is verified.
Output regulation problem for discrete-time linear time-delay systems by output feedback control
Institute of Scientific and Technical Information of China (English)
Yamin YAN; Jie HUANG
2016-01-01
In this paper, we study the output regulation problem of discrete linear time-delay systems by output feedback control. We have established some results parallel to those for the output regulation problem of continuous linear time-delay systems.
Scheifes, A.; Stolker, J.J.; Nijman, H.L.I.; Egberts, A.C.G.; Heerdink, E.R.
2011-01-01
Background Behavioural problems are common in people with intellectual disability (ID) and are often treated with antipsychotics. Aim To establish the frequency and characteristics of people with ID included in randomised controlled trials (RCTs) on antipsychotic treatment for behavioural problems
Ground-temperature controlling effects of duct-ventilated railway embankment in permafrost regions
Institute of Scientific and Technical Information of China (English)
NIU; Fujun; CHENG; Guodong
2004-01-01
Based on observed data from field-testing embankment of the Qinghai-Tibet Railway, ground-temperature controlling effect of duct-ventilated embankment is studied in this paper.The results show that ventilation ducts can effectively cool the soils surrounding the ducts of the embankment, and the heat budget of the ambient soils in a year shows as heat release. Temperature status of the permafrost below the embankment with ducts buried in the relatively high position is similar to that of the common embankment. The permafrost processes warming all along in the two freezing-thawing cycles when the embankment was constructed. However, the temperature of the frozen soils below the embankment, in which the ducts buried in the relatively low position, rises a little in the initial stage. After that, it cools down gradually. At the same time,ventilation ducts can effectively reduce the thermal disturbance caused by the filled soils. The frozen soils below the common embankment and that with high-posited ducts absorb heat all along in the initial two cycles. While the soils below the embankment with low-posited ducts begin to release heat in the second cycle. This phenomenon proves that the ventilation embankment with low-posited ducts shows efficient temperature-controlling effect. Such embankment can actively cool the subgrade soils and therefore keeps the roadbed thermally stable.
Study on Zero-Doppler Centroid Control for GEO SAR Ground Observation
Directory of Open Access Journals (Sweden)
Yicheng Jiang
2014-01-01
Full Text Available In geosynchronous Earth orbit SAR (GEO SAR, Doppler centroid compensation is a key step for imaging process, which could be performed by the attitude steering of a satellite platform. However, this zero-Doppler centroid control method does not work well when the look angle of radar is out of an expected range. This paper primarily analyzes the Doppler properties of GEO SAR in the Earth rectangular coordinate. Then, according to the actual conditions of the GEO SAR ground observation, the effective range is presented by the minimum and maximum possible look angles which are directly related to the orbital parameters. Based on the vector analysis, a new approach for zero-Doppler centroid control in GEO SAR, performing the attitude steering by a combination of pitch and roll rotation, is put forward. This approach, considering the Earth’s rotation and elliptical orbit effects, can accurately reduce the residual Doppler centroid. All the simulation results verify the correctness of the range of look angle and the proposed steering method.
Gentsch, Antje; Weber, Arne; Synofzik, Matthis; Vosgerau, Gottfried; Schütz-Bosbach, Simone
2016-01-01
The relation between motor control and action cognition - including action-related thoughts and action-related perception - has been subject to controversial discussions in the last three decades. During these decades, cognitive neuroscience has been increasingly confronted with a huge variety of different accounts trying to understand and explain the relation between these systems, their interdependencies and the mediating mechanisms by establishing notions such as "internal models", "simulation" or "shared representation". These accounts, however, include a large array of partly overlapping, partly contradictory theories using similar terms for different mechanisms and different terms for similar mechanisms. In the absence of a systematic work-up and comparison, this array of accounts and theories leads to confusion in the field, duplication of experimental work, and unconnected parallelism of theory formation within and between different disciplines. Here we provide a systematic comparison of current models and prospective theories that deal with the relation between cognition, perception and motor control mechanisms. In a second step, we propose "grounded action cognition" as a comprehensive metatheoretical framework which defines different hypothetical possibilities of the relations between these domains, offers systematic insights into current models and theories and last but not least may help to increase comparability of empirical research in the domain of action and action cognition.
Pantaleo, Michele; Walter, Thomas
2013-04-01
Temperature monitoring is a widespread procedure in the frame of volcano hazard monitoring. Indeed temperature changes are expected to reflect changes in volcanic activity. We propose a new approach, within the thermal monitoring, which is meant to shed light on the parameters controlling the fluid pathways and the fumarole sites by using infrared measurements. Ground-based infrared cameras allow one to remotely image the spatial distribution, geometric pattern and amplitude of fumarole fields on volcanoes at metre to centimetre resolution. Infrared mosaics and time series are generated and interpreted, by integrating geological field observations and modeling, to define the setting of the volcanic degassing system at shallow level. We present results for different volcano morphologies and show that lithology, structures and topography control the appearance of fumarole field by the creation of permeability contrasts. We also show that the relative importance of those parameters is site-dependent. Deciphering the setting of the degassing system is essential for hazard assessment studies because it would improve our understanding on how the system responds to endogenous or exogenous modification.
The H2 Control Problem for Quadratically Invariant Systems with Delays
Lamperski, Andrew; Doyle, John C.
2013-01-01
This paper gives a new solution to the output feedback H2 problem for quadratically invariant communication delay patterns. A characterization of all stabilizing controllers satisfying the delay constraints is given and the decentralized H2 problem is cast as a convex model matching problem. The main result shows that the model matching problem can be reduced to a finite-dimensional quadratic program. A recursive state-space method for computing the optimal controller based on vectorization i...
Gromakov, E. I.; Gazizov, A. T.; Lukin, V. P.; Chimrov, A. V.
2017-01-01
The paper analyses efficiency (interference resistance) of standard TT, TN, IT networks in control links of automatic control systems (ACS) of technical processes (TP) of oil and gas production. Electromagnetic compatibility (EMC) is a standard term used to describe the interference in grounding circuits. Improved EMC of ACS TP can significantly reduce risks and costs of malfunction of equipment that could have serious consequences. It has been proved that an IT network is the best type of grounds for protection of ACS TP in real life conditions. It allows reducing the interference down to the level that is stated in standards of oil and gas companies.
Institute of Scientific and Technical Information of China (English)
ZHANG DE-TAO
2009-01-01
In this paper, we use the solutions of forward-backward stochastic differential equations to get the optimal control for backward stochastic linear quadratic optimal control problem. And we also give the linear feedback regulator for the optimal control problem by using the solutions of a group of Riccati equations.
Institute of Scientific and Technical Information of China (English)
2008-01-01
In this paper,we investigate the Legendre Galerkin spectral approximation of quadratic optimal control problems governed by parabolic equations.A spectral approximation scheme for the parabolic optimal control problem is presented.We obtain a posteriori error estimates of the approximated solutions for both the state and the control.
Naderyan, Vahid; Hickey, Craig J.; Raspet, Richard
2016-02-01
Wind noise is a problem in seismic surveys and can mask the seismic signals at low frequency. This research investigates ground motions caused by wind pressure and shear stress perturbations on the ground surface. A prediction of the ground displacement spectra using the measured ground properties and predicted pressure and shear stress at the ground surface is developed. Field measurements are conducted at a site having a flat terrain and low ambient seismic noise. Triaxial geophones are deployed at different depths to study the wind-induced ground vibrations as a function of depth and wind velocity. Comparison of the predicted to the measured wind-induced ground displacement spectra shows good agreement for the vertical component but significant underprediction for the horizontal components. To validate the theoretical model, a test experiment is designed to exert controlled normal pressure and shear stress on the ground using a vertical and a horizontal mass-spring apparatus. This experiment verifies the linear elastic rheology and the quasi-static displacements assumptions of the model. The results indicate that the existing surface shear stress models significantly underestimate the wind shear stress at the ground surface and the amplitude of the fluctuation shear stress must be of the same order of magnitude as the normal pressure. Measurement results show that mounting the geophones flush with the ground provides a significant reduction in wind noise on all three components of the geophone. Further reduction in wind noise with depth of burial is small for depths up to 40 cm.
Stability Problems for Chua System with One Linear Control
Directory of Open Access Journals (Sweden)
Camelia Pop Arieşanu
2013-01-01
Full Text Available A Hamilton-Poisson realization and some stability problems for a dynamical system arisen from Chua system are presented. The stability and dynamics of a linearized smooth version of the Chua system are analyzed using the Hamilton-Poisson formalism. This geometrical approach allows to deduce the nonlinear stabilization near different equilibria.
The Library Space Problem, Future Demand, and Collection Control.
Lee, Hur-Li
1993-01-01
Outlines a model for determining library collection use, incorporating prediction of future demand and cost analysis to assist collection development librarians determine whether weeding or remote storage is the most economically feasible way to address the space problem in libraries. (13 references) (EA)
Comments on `A discrete optimal control problem for descriptor systems'
DEFF Research Database (Denmark)
Ravn, Hans
1990-01-01
In the above-mentioned work (see ibid., vol.34, p.177-81 (1989)), necessary and sufficient optimality conditions are derived for a discrete-time optimal problem, as well as other specific cases of implicit and explicit dynamic systems. The commenter corrects a mistake and demonstrates that there ...
Averaging and Linear Programming in Some Singularly Perturbed Problems of Optimal Control
Energy Technology Data Exchange (ETDEWEB)
Gaitsgory, Vladimir, E-mail: vladimir.gaitsgory@mq.edu.au [Macquarie University, Department of Mathematics (Australia); Rossomakhine, Sergey, E-mail: serguei.rossomakhine@flinders.edu.au [Flinders University, Flinders Mathematical Sciences Laboratory, School of Computer Science, Engineering and Mathematics (Australia)
2015-04-15
The paper aims at the development of an apparatus for analysis and construction of near optimal solutions of singularly perturbed (SP) optimal controls problems (that is, problems of optimal control of SP systems) considered on the infinite time horizon. We mostly focus on problems with time discounting criteria but a possibility of the extension of results to periodic optimization problems is discussed as well. Our consideration is based on earlier results on averaging of SP control systems and on linear programming formulations of optimal control problems. The idea that we exploit is to first asymptotically approximate a given problem of optimal control of the SP system by a certain averaged optimal control problem, then reformulate this averaged problem as an infinite-dimensional linear programming (LP) problem, and then approximate the latter by semi-infinite LP problems. We show that the optimal solution of these semi-infinite LP problems and their duals (that can be found with the help of a modification of an available LP software) allow one to construct near optimal controls of the SP system. We demonstrate the construction with two numerical examples.
GREEN‘S FUNCTION APPROACH IN APPROXIMATE CONTROLLABILITY PROBLEMS
Directory of Open Access Journals (Sweden)
Avetisyan A. S.
2016-06-01
Full Text Available A mathematical approach based on Green‘s function approach allowing to construct controls providing approximate controllability is suggested in the present paper. Representing the solution of governing system via Green’s formula and substituting it in prescribed terminal conditions, we obtain control functions providing approximate controllability of the system under study in explicit form. Choosing appropriate controls, we can provide required accuracy of approximation for prescribed conditions. Examples illustrating the procedure are described. Particularly, infinite string, controlled by a concentrated force, semi-infinite rod heated by a point heat source, finite rod heated from its boundary and parameter optimization for electrical circuit are considered. Results of computsations are brought.
Fuzzy Adaptive Control for Intelligent Autonomous Space Exploration Problems
Esogbue, Augustine O.
1998-01-01
The principal objective of the research reported here is the re-design, analysis and optimization of our newly developed neural network fuzzy adaptive controller model for complex processes capable of learning fuzzy control rules using process data and improving its control through on-line adaption. The learned improvement is according to a performance objective function that provides evaluative feedback; this performance objective is broadly defined to meet long-range goals over time. Although fuzzy control had proven effective for complex, nonlinear, imprecisely-defined processes for which standard models and controls are either inefficient, impractical or cannot be derived, the state of the art prior to our work showed that procedures for deriving fuzzy control, however, were mostly ad hoc heuristics. The learning ability of neural networks was exploited to systematically derive fuzzy control and permit on-line adaption and in the process optimize control. The operation of neural networks integrates very naturally with fuzzy logic. The neural networks which were designed and tested using simulation software and simulated data, followed by realistic industrial data were reconfigured for application on several platforms as well as for the employment of improved algorithms. The statistical procedures of the learning process were investigated and evaluated with standard statistical procedures (such as ANOVA, graphical analysis of residuals, etc.). The computational advantage of dynamic programming-like methods of optimal control was used to permit on-line fuzzy adaptive control. Tests for the consistency, completeness and interaction of the control rules were applied. Comparisons to other methods and controllers were made so as to identify the major advantages of the resulting controller model. Several specific modifications and extensions were made to the original controller. Additional modifications and explorations have been proposed for further study. Some of
Enclothed Cognition and Controlled Attention during Insight Problem-Solving
Van Stockum, Charles A., Jr.; DeCaro, Marci S.
2014-01-01
Individual differences in working memory capacity (WMC) increase the ability and tendency to devote greater attentional control to a task--improving performance on a wide range of skills. In addition, recent research on enclothed cognition demonstrates that the situational influence of wearing a white lab coat increases controlled attention, due…
Some Stochastic Control Problems in Manufacturing, Communications and Computer Systems
1988-05-01
Rate in a Failure Prone Manufacturing System," IEEE Transactions on Automatic Control , pp. 116-126, vol. AC-31, No. 2., February 1986. 3. R. Akella...Assembly/Disassembly Systems," submitted to IEEE Transactions on Automatic Control , December 4, 1987. 14. D. P. Connors and P. R. Kumar. "Simulated
Phosphorus fertilization for rice and control of environmental pollution problems.
Choudhury, A T M A; Kennedy, I R; Ahmed, M F; Kecskés, M L
2007-07-01
Aim of this study to review information on various aspects of P fertilization in rice i.e., P nutrition of rice, P response of rice plant, P availability in rice soils and P adsorption in rice soils for better understanding of P fertilization in rice culture. A substantial portion of the applied P along with the soil P is lost from rice fields to water bodies causing environmental pollution problems through eutrophication. These pollution problems can be minimized by using proper source of P as fertilizer, proper timing and methods of P fertilizer application, soil P management, transport management, use of plant growth promoting microorganisms which helps in efficient use of P by crops and use of green manure crops which improves soil fertility as well as helps in efficient use of P by crops.
Directory of Open Access Journals (Sweden)
José M. Sánchez Vázqez
2006-12-01
Full Text Available As part of the supply chain, manufacturing firms are increasingly placing greater emphasis on the management of their outsourced distribution channels (DCs. However, the role that interorganizational Management Control Systems (MCS can play in managing DC problems is still not clearly understood. Through an exploratory case study, we show how intra-organizational control problems persist in an inter-organizational context, rooted in informational asymmetries and conflicts of interest and aggravated by interdependencies. Likewise, the case study illustrates the way in which MCS assists the manufacturing firm to communicate to its representatives what the organization wants from them, motivating them and transferring capabilities. Thus, MCS can help to complement and re-orientate inter-firm agreements and constitutes a key tool for managing DCs in a flexible way.Como parte de la cadena de suministros, las empresas productoras están poniendo mayor énfasis en la gestión de sus canales de distribución externalizados (DCs. Sin embargo, aún no existe una clara comprensión sobre el papel que los Sistemas de Control de Gestión inter-organizativos (MCS pueden desarrollar en la gestión de los problemas de los DCs. A través de un estudio de caso, se muestra cómo los problemas de control intra-organizativos persisten en un contexto inter-organizativo, causados por las asimetrías informativas y el conflicto de intereses, y agravándose por las interdependencias. Asimismo, se expone cómo los MCS ayudan a la empresa productora a comunicar a sus distribuidores lo que la organización desea de ellos, motivándolos y capacitándolos. De esta forma, los MCS pueden ayudar a completar y redirigir acuerdos entre firmas y constituir una herramienta clave en la gestión flexible de los DCs.
Institute of Scientific and Technical Information of China (English)
宗云峰
2012-01-01
分析了淮南矿区近年来在采煤沉陷区移民安置工作中所取得的成果和面临的难题，探讨了如何做好采煤沉陷区移民安置工作，可为煤炭企业提供经验与借鉴。%The paper analyzed the achievements and faced problems of the immigration resettlements of the ground subsidence area caused by underground coal mining and discussed how to well done the immigration resettlements of the ground subsidence area, which could provide the experiences and references to the coal enterprises.
Solving the optimal attention allocation problem in manual control
Kleinman, D. L.
1976-01-01
Within the context of the optimal control model of human response, analytic expressions for the gradients of closed-loop performance metrics with respect to human operator attention allocation are derived. These derivatives serve as the basis for a gradient algorithm that determines the optimal attention that a human should allocate among several display indicators in a steady-state manual control task. Application of the human modeling techniques are made to study the hover control task for a CH-46 VTOL flight tested by NASA.
Design of a Nanosatellite Ground Monitoring and Control Software – a Case Study
Directory of Open Access Journals (Sweden)
Freddy Alexander Díaz González
2016-04-01
Full Text Available The growing countries that have carried out the development of CubeSat missions for academic purposes do not offer aerospace engineering programs at their universities. This causes difficulties for traditional engineers upon the formal use of different standards and frameworks for aerospace development, such as the European Cooperation for Space Standardization and Space Mission Analysis and Design . One way in which traditional software engineers can easily understand the structure of an aerospace framework, in order to apply it on the development of CubeSat mission software parts, is comparing its most important elements in relation to the elements suggested by a more familiar method. In this paper, we present a hybrid framework between the ECSS-E-ST-40C standard and the Rational Unified Process, which can be used by traditional software engineers as a guide model for the development of software elements in academic nanosatellite missions. The model integrates the processes and documentation suggested by the ECSS-E-ST-40C with the disciplines, workflows and artifacts suggested in Rational Unified Process. This simplifies the structure of ECSS-E-ST-40C and allows traditional software engineers to easily understand its work elements. The paper describes as study case the implementation of the hybrid model in the analysis and design of ground monitoring and control software for the Libertad-2 satellite mission, which is currently being developed by the Universidad Sergio Arboleda in Colombia.
Directory of Open Access Journals (Sweden)
Yao Chen
2017-01-01
Full Text Available In this paper, a compact frequency reconfigurable circular patch antenna with an arc-shaped slot loaded in the ground layer is proposed for multiband wireless communication applications. By controlling the ON/OFF states of the five PIN diodes mounted on the arc-shaped slot, the effective length of the arc-shaped slot and the effective length of antennas current are changed, and accordingly six-frequency band reconfiguration can be achieved. The simulated and measured results show that the antenna can operate from 1.82 GHz to 2.46 GHz, which is located in DCS1800 (1.71–1.88 GHz, UMTS (2.11–2.20 GHz, WiBro (2.3–2.4 GHz, and Bluetooth (2.4–2.48 GHz frequency bands and so forth. Compared to the common rectangular slot circular patch antenna, the proposed arc-shaped slot circular patch antenna not only has a better rotational symmetry with the circular patch and substrate but also has more compact size. For the given operating frequency at 1.82 GHz, over 55% area reduction is achieved in this design with respect to the common design with rectangular slot. Since the promising frequency reconfiguration, this antenna may have potential applications in modern multiband and multifunctional mobile communication systems.
ORGANIZATIONAL AND ECONOMIC MODELING IN SOLVING PROBLEMS OF CONTROLLING
Kulikova S. Y.; Muravyeva V. S.; Orlov A. I.
2016-01-01
At the Department of "Economics and organization of production" at the end of XX - beginning of XXI centuries created the scientific school in the field of organizational and economic modeling, econometrics and statistics. The same name section of the department oversees the teaching of the relevant disciplines. The Laboratory of economic and mathematical methods in controlling of the Research and Education Center "Controlling and innovation in management" of Bauman Moscow State Technical Uni...
Control and stability problems of remote orbital capture
Kaplan, M. H.; Nadkarni, A. A.
1977-01-01
Certain space shuttle missions may require retrieval of passive spinning and precessing satellites. One proposed means of retrieval utilizes a free-flying teleoperator launched from the shuttle. A study of misalignment, stability, and certain control aspects during capture of an object is reported here. The approach used is to model the dynamics by a Lagrangian formulation and apply torque components to dissipate motion. Differential angular rates between teleoperator and object are assumed, and control responses after capture are reviewed.
Uncertainty Quantification in Control Problems for Flocking Models
Directory of Open Access Journals (Sweden)
Giacomo Albi
2015-01-01
Full Text Available The optimal control of flocking models with random inputs is investigated from a numerical point of view. The effect of uncertainty in the interaction parameters is studied for a Cucker-Smale type model using a generalized polynomial chaos (gPC approach. Numerical evidence of threshold effects in the alignment dynamic due to the random parameters is given. The use of a selective model predictive control permits steering of the system towards the desired state even in unstable regimes.
Directory of Open Access Journals (Sweden)
Yekini Shehu
2010-01-01
real Banach space which is also uniformly smooth using the properties of generalized f-projection operator. Using this result, we discuss strong convergence theorem concerning general H-monotone mappings and system of generalized mixed equilibrium problems in Banach spaces. Our results extend many known recent results in the literature.
On a Non-Standard Stochastic Control Problem
Ekeland, Ivar
2008-01-01
This paper considers the Merton portfolio management problem. We are concerned with non-exponential discounting of time and this leads to time inconsistencies of the decision maker. Following Ekeland and Pirvu 2006, we introduce the notion of equilibrium policies and we characterize them by an integral equation. The main idea is to come up with the value function in this context. If risk preferences are of CRRA type, the integral equation which characterizes the value function is shown to have a solution which leads to an equilibrium policy. This work is an extension of Ekeland and Pirvu 2006.
Directory of Open Access Journals (Sweden)
Sona Suhartana
2004-11-01
• The average of ground exposure caused by controlled skidding technique and conventionalskidding technique was respectively 16.06% and 18.4%. The difference of 2.34% was significant at 95%.
Wang, J.; Ge, Y.; Heuvelink, G.B.M.; Zhou, C.; Brus, D.J.
2012-01-01
The acquirement of ground control points (GCPs) is a basic and important step in the geometric correction of remotely sensed imagery. In particular, the spatial distribution of GCPs may affect the accuracy and quality of image correction. In this paper, both a simulation experiment and actual-image
van Woezik, Anne F. G.; Braakman-Jansen, Louise M. A.; Kulyk, Olga; Siemons, Liseth; van Gemert-Pijnen, Julia E. W. C.
2016-01-01
Background: Infection prevention and control can be seen as a wicked public health problem as there is no consensus regarding problem definition and solution, multiple stakeholders with different needs and values are involved, and there is no clear end-point of the problem-solving process. Co-creati
van Woezik, Anne; Braakman-Jansen, Louise Marie Antoinette; Kulyk, Olga Anatoliyivna; Tjin-Kam-Jet-Siemons, Liseth; van Gemert-Pijnen, Julia E.W.C.
2016-01-01
Background Infection prevention and control can be seen as a wicked public health problem as there is no consensus regarding problem definition and solution, multiple stakeholders with different needs and values are involved, and there is no clear end-point of the problem-solving process. Co-creatio
Woezik, van A.F.G.; Braakman-Jansen, L.M.A.; Kulyk, O.; Siemons, L.; Gemert-Pijnen, van J.E.W.C.
2016-01-01
Background Infection prevention and control can be seen as a wicked public health problem as there is no consensus regarding problem definition and solution, multiple stakeholders with different needs and values are involved, and there is no clear end-point of the problem-solving process. Co-creatio
An optimal control problem for ovine brucellosis with culling.
Nannyonga, B; Mwanga, G G; Luboobi, L S
2015-01-01
A mathematical model is used to study the dynamics of ovine brucellosis when transmitted directly from infected individual, through contact with a contaminated environment or vertically through mother to child. The model developed by Aïnseba et al. [A model for ovine brucellosis incorporating direct and indirect transmission, J. Biol. Dyn. 4 (2010), pp. 2-11. Available at http://www.math.u-bordeaux1.fr/∼pmagal100p/papers/BBM-JBD09.pdf. Accessed 3 July 2012] was modified to include culling and then used to determine important parameters in the spread of human brucellosis using sensitivity analysis. An optimal control analysis was performed on the model to determine the best way to control such as a disease in the population. Three time-dependent controls to prevent exposure, cull the infected and reduce environmental transmission were used to set up to minimize infection at a minimum cost.
Nolte, Lizette; Wren, Bernadette
2016-10-01
This grounded theory study explored parents' experiences of responding to their children's need for understanding parental mental health concerns. Fifteen parents with severe and enduring mental health difficulties participated in the study. The findings suggest four main social processes that influence parents' talk with their children about parental mental health issues, namely "Protecting and being protected," "Responding to children's search for understanding," "Prioritizing family life," and "Relating to others." Implications of the findings for clinical practice and future research are considered. In particular, the need for more family-orientated services where parents experience parental mental health problems is highlighted.
General problems of dynamics and control of vibratory gyroscopes
CSIR Research Space (South Africa)
Shatalov, MY
2008-05-01
Full Text Available A general model of operation of vibratory gyroscopes, which is applicable to a broad class of instruments, including cylindrical, disc and micro-machined gyros, is formulated on the basis of analysis of dynamics and control of a hemispherical...
Parallel Implementation of Riccati Recursion for Solving Linear-Quadratic Control Problems
DEFF Research Database (Denmark)
Frison, Gianluca; Jørgensen, John Bagterp
2013-01-01
In both Active-Set (AS) and Interior-Point (IP) algorithms for Model Predictive Control (MPC), sub-problems in the form of linear-quadratic (LQ) control problems need to be solved at each iteration. The solution of these sub-problems is usually the main computational effort. In this paper...... an alternative version of the Riccati recursion solver for LQ control problems is presented. The performance of both the classical and the alternative version is analyzed from a theoretical as well as a numerical point of view, and the alternative version is found to be approximately 50% faster than...
Directory of Open Access Journals (Sweden)
Sie Long Kek
2015-01-01
Full Text Available A computational approach is proposed for solving the discrete time nonlinear stochastic optimal control problem. Our aim is to obtain the optimal output solution of the original optimal control problem through solving the simplified model-based optimal control problem iteratively. In our approach, the adjusted parameters are introduced into the model used such that the differences between the real system and the model used can be computed. Particularly, system optimization and parameter estimation are integrated interactively. On the other hand, the output is measured from the real plant and is fed back into the parameter estimation problem to establish a matching scheme. During the calculation procedure, the iterative solution is updated in order to approximate the true optimal solution of the original optimal control problem despite model-reality differences. For illustration, a wastewater treatment problem is studied and the results show the efficiency of the approach proposed.
Efficient Implementation of the Riccati Recursion for Solving Linear-Quadratic Control Problems
DEFF Research Database (Denmark)
Frison, Gianluca; Jørgensen, John Bagterp
2013-01-01
In both Active-Set (AS) and Interior-Point (IP) algorithms for Model Predictive Control (MPC), sub-problems in the form of linear-quadratic (LQ) control problems need to be solved at each iteration. The solution of these sub-problems is typically the main computational effort at each iteration....... In this paper, we compare a number of solvers for an extended formulation of the LQ control problem: a Riccati recursion based solver can be considered the best choice for the general problem with dense matrices. Furthermore, we present a novel version of the Riccati solver, that makes use of the Cholesky...... factorization of the Pn matrices to reduce the number of flops. When combined with regularization and mixed precision, this algorithm can solve large instances of the LQ control problem up to 3 times faster than the classical Riccati solver....
Chernov, A. V.
2013-12-01
Approximating finite-dimensional mathematical programming problems are studied that arise from piecewise constant discretization of controls in the optimization of distributed systems of a fairly broad class. The smoothness of the approximating problems is established. Gradient formulas are derived that make use of the analytical solution of the original control system and its adjoint, thus providing an opportunity for algorithmic separation of numerical optimization and the task of solving a controlled initial-boundary value problem. The approximating problems are proved to converge to the original optimization problem with respect to the functional as the discretization is refined. The application of the approach to optimization problems is illustrated by solving the semilinear wave equation controlled by applying an integral criterion. The results of numerical experiments are analyzed.
A Constraint Programming Approach for Solving a Queueing Control Problem
Terekhov, Daria; 10.1613/jair.2446
2011-01-01
In a facility with front room and back room operations, it is useful to switch workers between the rooms in order to cope with changing customer demand. Assuming stochastic customer arrival and service times, we seek a policy for switching workers such that the expected customer waiting time is minimized while the expected back room staffing is sufficient to perform all work. Three novel constraint programming models and several shaving procedures for these models are presented. Experimental results show that a model based on closed-form expressions together with a combination of shaving procedures is the most efficient. This model is able to find and prove optimal solutions for many problem instances within a reasonable run-time. Previously, the only available approach was a heuristic algorithm. Furthermore, a hybrid method combining the heuristic and the best constraint programming method is shown to perform as well as the heuristic in terms of solution quality over time, while achieving the same performanc...
Garza, Sergio
1983-01-01
The U.S. Army Corps of Engineers' plan to control the natural chloride pollution in the Wichita River basin includes the construction of Truscott Brine Lake on a tributary of the North Wichita River. In connection with the proposed brine lake, the U.S. Geological Survey was requested to: (1) Define the existing ground-water conditions in the shallow fresh-water system of the project area; and (2) project the post-construction effects of the proposed lake on the fresh-water aquifer, especially in relation to hydraulic-head changes but also with respect to possible changes in the chemical quality of the ground water.
Numerical Methods for Solution of the Extended Linear Quadratic Control Problem
DEFF Research Database (Denmark)
Jørgensen, John Bagterp; Frison, Gianluca; Gade-Nielsen, Nicolai Fog
2012-01-01
to the Karush-Kuhn-Tucker system that constitute the majority of computational work in constrained nonlinear and linear model predictive control problems solved by efficient MPC-tailored interior-point and active-set algorithms. We state various methods of solving the extended linear quadratic control problem...
Kim, Geunyoung; Walden, Tedra; Harris, Vicki; Karrass, Jan; Catron, Thomas
2007-01-01
The present study examined the role of emotion and emotion control in children's externalizing problems. Third- to sixth-grade children were administered a self-report measure of positive emotion, negative emotion, and emotion control. Peer- and teacher-reported adjustment problems were assessed. Structural equations modeling revealed that…
Four of a kind: asthma control, FEV1, FeNO, and psychosocial problems in adolescents
Tibosch, M.M.; Ridder, J. de; Landstra, A.; Hugen, C.A.; Brouwer, M.; Gerrits, P.; Gent, R. van; Roukema, J.; Verhaak, C.M.; Merkus, P.J.
2012-01-01
BACKGROUND: Many adolescents have poor asthma control and are at high risk for psychosocial problems. However, structured assessment of asthma control or psychosocial problems is still not implemented in routine asthma care. Pediatricians typically rely on their clinical view and physiological measu
Time-Inconsistent Optimal Control Problems and the Equilibrium HJB Equation
Yong, Jiongmin
2012-01-01
A general time-inconsistent optimal control problem is considered for stochastic differential equations with deterministic coefficients. Under suitable conditions, a Hamilton-Jacobi-Bellman type equation is derived for the equilibrium value function of the problem. Well-posedness and some properties of such an equation is studied, and time-consistent equilibrium strategies are constructed. As special cases, the linear-quadratic problem and a generalized Merton's portfolio problem are investigated.
A maximum principle for smooth optimal impulsive control problems with multipoint state constraints
Dykhta, V. A.; Samsonyuk, O. N.
2009-06-01
A nonlinear optimal impulsive control problem with trajectories of bounded variation subject to intermediate state constraints at a finite number on nonfixed instants of time is considered. Features of this problem are discussed from the viewpoint of the extension of the classical optimal control problem with the corresponding state constraints. A necessary optimality condition is formulated in the form of a smooth maximum principle; thorough comments are given, a short proof is presented, and examples are discussed.
Enokida, Ryuta; Takewaki, Izuru; Stoten, David
2014-12-01
The problem of control system design can be conceptualised as identifying an input signal to a plant (the system to be controlled) so that the corresponding output matches that of a pre-defined reference signal. Primarily, this problem is solved via well-known techniques based upon the principle of feedback design, an essential component for ensuring stability and robustness of the controlled system. However, feedforward design techniques also have a large part to play, whereby (in the absence of feedback control and assuming that the plant is stable) a model of the plant dynamics can be used to modify the reference signal so that the resultant feedforward input signal generates a plant output signal that is sufficiently close to the original reference signal. The principal objective of this paper is to introduce a new nonlinear control method, called nonlinear signal-based control (NSBC) that can be executed as an on-line technique of feedforward compensation (used synonymously here with the phrase 'input identification') and an off-line technique of feedback compensation. NSBC determines the feedforward input signal to the plant by using an error signal, determined from the difference between the output signals from a linear model of the plant and from the nonlinear plant, under the same input signal. The efficacy of NSBC is examined via numerical examples using Matlab/Simulink and compared with alternative well-known methods based upon inverse transfer function compensation and also the method of high gain feedback control. NSBC was found to provide the most accurate input identification in all the examined cases of linear or nonlinear single-input, single-output and single-input, multi-output (SIMO) systems. Furthermore, in problems of structural and earthquake engineering, NSBC was also found to be particularly effective in estimating the original ground motion from a nonlinear SIMO system and its response.
Deterministic Time-inconsistent Optimal Control Problems - an Essentially Cooperative Approach
Institute of Scientific and Technical Information of China (English)
Jiong-min YONG
2012-01-01
A general deterministic time-inconsistent optimal control problem is formulated for ordinary differential equations.To find a time-consistent equilibrium value function and the corresponding time-consistent equilibrium control,a non-cooperative N-person differential game (but essentially cooperative in some sense) is introduced.Under certain conditions,it is proved that the open-loop Nash equilibrium value function of the N-person differential game converges to a time-consistent equilibrium value function of the original problem,which is the value function of a time-consistent optimal control problem.Moreover,it is proved that any optimal control of the time-consistent limit problem is a time-consistent equilibrium control of the original problem.
A Fast Condensing Method for Solution of Linear-Quadratic Control Problems
DEFF Research Database (Denmark)
Frison, Gianluca; Jørgensen, John Bagterp
2013-01-01
In both Active-Set (AS) and Interior-Point (IP) algorithms for Model Predictive Control (MPC), sub-problems in the form of linear-quadratic (LQ) control problems need to be solved at each iteration. The solution of these sub-problems is usually the main computational effort. In this paper we...... consider a condensing (or state elimination) method to solve an extended version of the LQ control problem, and we show how to exploit the structure of this problem to both factorize the dense Hessian matrix and solve the system. Furthermore, we present two efficient implementations. The first...... implementation is formally identical to the Riccati recursion based solver and has a computational complexity that is linear in the control horizon length and cubic in the number of states. The second implementation has a computational complexity that is quadratic in the control horizon length as well...
Instrument Display Visual Angles for Conventional Aircraft and the MQ-9 Ground Control Station
Bendrick, Gregg A.; Kamine, Tovy Haber
2008-01-01
Aircraft instrument panels should be designed such that primary displays are in optimal viewing location to minimize pilot perception and response time. Human Factors engineers define three zones (i.e. "cones") of visual location: 1) "Easy Eye Movement" (foveal vision); 2) "Maximum Eye Movement" (peripheral vision with saccades), and 3) "Head Movement" (head movement required). Instrument display visual angles were measured to determine how well conventional aircraft (T-34, T-38, F- 15B, F-16XL, F/A-18A, U-2D, ER-2, King Air, G-III, B-52H, DC-10, B747-SCA) and the MQ-9 ground control station (GCS) complied with these standards, and how they compared with each other. Methods: Selected instrument parameters included: attitude, pitch, bank, power, airspeed, altitude, vertical speed, heading, turn rate, slip/skid, AOA, flight path, latitude, longitude, course, bearing, range and time. Vertical and horizontal visual angles for each component were measured from the pilot s eye position in each system. Results: The vertical visual angles of displays in conventional aircraft lay within the cone of "Easy Eye Movement" for all but three of the parameters measured, and almost all of the horizontal visual angles fell within this range. All conventional vertical and horizontal visual angles lay within the cone of "Maximum Eye Movement". However, most instrument vertical visual angles of the MQ-9 GCS lay outside the cone of "Easy Eye Movement", though all were within the cone of "Maximum Eye Movement". All the horizontal visual angles for the MQ-9 GCS were within the cone of "Easy Eye Movement". Discussion: Most instrument displays in conventional aircraft lay within the cone of "Easy Eye Movement", though mission-critical instruments sometimes displaced less important instruments outside this area. Many of the MQ-9 GCS systems lay outside this area. Specific training for MQ-9 pilots may be needed to avoid increased response time and potential error during flight.
Environmental Controls on Above-Ground Biomass in the Taita Hills, Kenya
Adhikari, H.; Heiskanen, J.; Siljander, M.; Maeda, E. E.; Heikinheimo, V.; Pellikka, P.
2016-12-01
Tropical forests are globally significant ecosystems which maintain high biodiversity and provide valuable ecosystem services, including carbon sink, climate change mitigation and adaptation. This ecosystem has been severely degraded for decades. However, the magnitude and spatial patterns of the above ground biomass (AGB) in the tropical forest-agriculture landscapes is highly variable, even under the same climatic condition and land use. This work aims 1) to generate wall-to-wall map of AGB density for the Taita Hills in Kenya based on field measurements and airborne laser scanning (ALS) and 2) to examine environmental controls on AGB using geospatial data sets on topography, soils, climate and land use, and statistical modelling. The study area (67000 ha) is located in the northernmost part of the Eastern Arc Mountains of Kenya and Tanzania, and the highest hilltops reach over 2200 m in elevation. Most of the forest area has been cleared for croplands and agroforestry, and hills are surrounded by the semi-arid scrublands and dry savannah at an elevation of 600-900 m a.s.l. As a result, the current land cover is a mosaic of various types of land cover and land use. The field measurements were carried out in total of 216 plots in 2013-2015 for AGB computations and ALS flights were conducted in 2014-2015. AGB map at 30 m x 30 m resolution was implemented using multiple linear regression based on ALS variables derived from the point cloud, namely canopy cover and 25 percentile height of ALS returns (R2 = 0.88). Boosted regression trees (BRT) was used for examining the relationship between AGB and explanatory variables, which were derived from ALS-based high resolution DEM (2 m resolution), soil database, downscaled climate data and land cover/use maps based on satellite image analysis. The results of these analyses will be presented in the conference.
Controlling sign problems in spin models using tensor renormalization
Energy Technology Data Exchange (ETDEWEB)
Denbleyker, Alan [Iowa U.; Liu, Yuzhi [Colorado U.; Meurice, Y. [Iowa U.; Qin, M. P. [Beijing, Inst. Phys.; Xiang, T. [Beijing, Inst. Phys.; Xie, Z. Y. [Beijing, Inst. Phys.; Yu, J. F. [Beijing, Inst. Phys.; Zou, Haiyuan [Iowa U.
2014-01-09
We consider the sign problem for classical spin models at complex $\\beta =1/g_0^2$ on $L\\times L$ lattices. We show that the tensor renormalization group method allows reliable calculations for larger Im$\\beta$ than the reweighting Monte Carlo method. For the Ising model with complex $\\beta$ we compare our results with the exact Onsager-Kaufman solution at finite volume. The Fisher zeros can be determined precisely with the TRG method. We check the convergence of the TRG method for the O(2) model on $L\\times L$ lattices when the number of states $D_s$ increases. We show that the finite size scaling of the calculated Fisher zeros agrees very well with the Kosterlitz-Thouless transition assumption and predict the locations for larger volume. The location of these zeros agree with Monte Carlo reweighting calculation for small volume. The application of the method for the O(2) model with a chemical potential is briefly discussed.
A boundary control problem with a nonlinear reaction term
Directory of Open Access Journals (Sweden)
John R. Cannon
2009-04-01
Full Text Available The authors study the problem $u_t=u_{xx}-au$, $0
Direct SQP-methods for solving optimal control problems with delays
Energy Technology Data Exchange (ETDEWEB)
Goellmann, L.; Bueskens, C.; Maurer, H.
1994-12-31
The maximum principle for optimal control problems with delays leads to a boundary value problem (BVP) which is retarded in the state and advanced in the costate function. Based on shooting techniques, solution methods for this type of BVP have been proposed. In recent years, direct optimization methods have been favored for solving control problems without delays. Direct methods approximate the control and the state over a fixed mesh and solve the resulting NLP-problem with SQP-methods. These methods dispense with the costate function and have shown to be robust and efficient. In this paper, we propose a direct SQP-method for retarded control problems. In contrast to conventional direct methods, only the control variable is approximated by e.g. spline-functions. The state is computed via a high order Runge-Kutta type algorithm and does not enter explicitly the NLP-problem through an equation. This approach reduces the number of optimization variables considerably and is implementable even on a PC. Our method is illustrated by the numerical solution of retarded control problems with constraints. In particular, we consider the control of a continuous stirred tank reactor which has been solved by dynamic programming. This example illustrates the robustness and efficiency of the proposed method. Open questions concerning sufficient conditions and convergence of discretized NLP-problems are discussed.
Optimal control problems with switching points. Ph.D. Thesis, 1990 Final Report
Seywald, Hans
1991-01-01
An overview is presented of the problems and difficulties that arise in solving optimal control problems with switching points. A brief discussion of existing optimality conditions is given and a numerical approach for solving the multipoint boundary value problems associated with the first-order necessary conditions of optimal control is presented. Two real-life aerospace optimization problems are treated explicitly. These are altitude maximization for a sounding rocket (Goddard Problem) in the presence of a dynamic pressure limit, and range maximization for a supersonic aircraft flying in the vertical, also in the presence of a dynamic pressure limit. In the second problem singular control appears along arcs with active dynamic pressure limit, which in the context of optimal control, represents a first-order state inequality constraint. An extension of the Generalized Legendre-Clebsch Condition to the case of singular control along state/control constrained arcs is presented and is applied to the aircraft range maximization problem stated above. A contribution to the field of Jacobi Necessary Conditions is made by giving a new proof for the non-optimality of conjugate paths in the Accessory Minimum Problem. Because of its simple and explicit character, the new proof may provide the basis for an extension of Jacobi's Necessary Condition to the case of the trajectories with interior point constraints. Finally, the result that touch points cannot occur for first-order state inequality constraints is extended to the case of vector valued control functions.
Gas emission problems in starting the workings and controlling measures
Energy Technology Data Exchange (ETDEWEB)
Kunz, E. [Deutsche Montan Technologie GmbH, Essen (Germany)
2001-07-01
When a working is being started and especially if the face advances very quickly from the beginning, there may occur sudden releases of large gas amounts from the roof as well as from the floor. Apparently, this risk arises quite frequently if there are extremely solid rock layers of only few-meter thickness (up to 10 m) between the working seam and a gaseous seam within the area of gas emission. In the Ruhr deposit these layers consist of sandy shale and sandstones. Consequently, it is necessary to know the rock sequence and its mechanical characteristics in roof and floor for the early detection of gas outbursts. If a longwall is planned in a rock formation of this kind one has to prepare a preventive drilling scheme for the starting front and gas drainage should start already before the winning work. Experience in one working has shown that even in the immediate starting phase large gas amounts can be released and drained respectively. Models were built that represented different rock sequences and it was possible to simulate the processes that occured when the area of gas emissions was opening during the start of a working for these rock sequences. According to that one has to expect even an obstruction of gas emission under certain conditions. Additionally, such an obstruction of gas emission can be detected early, too, with the continuous calculation of the accumulated gas make which should be carried out from the first day of winning work. Normally, there is a continuously even increase. If the accumulated gas make levels off or even decreases, this is a clear sign for problems in the steady opening of the gas emission zone. 1 ref., 8 figs.
SHAPE STABILITY OF OPTIMAL CONTROL PROBLEMS IN COEFFICIENTS FOR COUPLED SYSTEM OF HAMMERSTEIN TYPE
Directory of Open Access Journals (Sweden)
P. I. Kogut
2014-01-01
Full Text Available In this paper we consider an optimal control problem (OCP for the coupledsystem of a nonlinear monotone Dirichlet problem with matrix-valued L∞(Ω;RN×N-controls in coecients and a nonlinear equation of Hammerstein type, where solution nonlinearly depends on L∞ -control. Since problems of this type have no solutions in general, we make a special assumption on the coecients of the state equations and introduce the class of so-called solenoidal admissible controls. Using the direct method in calculus of variations, we prove the existence of an optimal control. We also study the stability of the optimal control problem with respect to the domain perturbation. In particular, we derive the sucient conditions of the Mosco-stability for the given class of OCPs.
DEFF Research Database (Denmark)
Nielsen, Rasmus Kleis
Political campaigns today are won or lost in the so-called ground war--the strategic deployment of teams of staffers, volunteers, and paid part-timers who work the phones and canvass block by block, house by house, voter by voter. Ground Wars provides an in-depth ethnographic portrait of two...... infrastructures that utilize large databases with detailed individual-level information for targeting voters, and armies of dedicated volunteers and paid part-timers. Nielsen challenges the notion that political communication in America must be tightly scripted, controlled, and conducted by a select coterie...... of professionals. Yet he also quashes the romantic idea that canvassing is a purer form of grassroots politics. In today's political ground wars, Nielsen demonstrates, even the most ordinary-seeming volunteer knocking at your door is backed up by high-tech targeting technologies and party expertise. Ground Wars...
A new solution to wireless sensor network density control problem
Institute of Scientific and Technical Information of China (English)
SHI Jian; JIA Yu-fu; DONG Tian-lin; LI Jiang
2006-01-01
In this paper,we proposed a scheme based on Monte Carlo algorithm to test whether or not the nodes are redundant for realizing the node density control in the sensor network.The computational complexity is only O(n).We also established the coverage collision detection and back-off mechanism applied in the wireless sensor network.The simulation results show that the system can cover all the interested area with the smallest number of nodes and a coverage void will not appear during the course of state-transition.The coverage collision detection and back-off mechanism proposed in this article can be applied when the nodes have either synchronous or asynchronous mechanism.It also provides a stable stage with the length of the time that can be adjusted.
Experiments on Socio-Technical Systems: The Problem of Control.
Kroes, Peter
2016-06-01
My aim is to question whether the introduction of new technologies in society may be considered to be genuine experiments. I will argue that they are not, at least not in the sense in which the notion of experiment is being used in the natural and social sciences. If the introduction of a new technology in society is interpreted as an experiment, then we are dealing with a notion of experiment that differs in an important respect from the notion of experiment as used in the natural and social sciences. This difference shows itself most prominently when the functioning of the new technological system is not only dependent on technological hardware but also on social 'software', that is, on social institutions such as appropriate laws, and actions of operators of the new technological system. In those cases we are not dealing with 'simply' the introduction of a new technology, but with the introduction of a new socio-technical system. I will argue that if the introduction of a new socio-technical system is considered to be an experiment, then the relation between the experimenter and the system on which the experiment is performed differs significantly from the relation in traditional experiments in the natural and social sciences. In the latter experiments it is assumed that the experimenter is not part of the experimental system and is able to intervene in and control the experimental system from the outside. With regard to the introduction of new socio-technical systems the idea that there is an experimenter outside the socio-technical system who intervenes in and controls that system becomes problematic. From that perspective we are dealing with a different kind of experiment.
Relaxation Methods for Hyperbolic PDE Mixed-Integer Optimal Control Problems
Hante, Falk M.
2015-01-01
We extend the convergence analysis for methods solving PDE-constrained optimal control problems containing both discrete and continuous control decisions based on relaxation and rounding strategies to the class of first order semilinear hyperbolic systems in one space dimension. The results are obtained by novel a-priori estimates for the size of the relaxation gap based on the characteristic flow, fixed-point arguments and particular regularity theory for such mixed-integer control problems....
Pre-school Teachers’ Perceived Control and Behaviour Problems in Children
Hammarberg, Annie
2003-01-01
In this thesis, pre-school teachers’ perceived control, is examined in relation to problem behaviours of children and the actions of teachers in the classroom. In addition, other factors that are thought to relate to teachers’ perceived control were studied. The results of Study I indicate that pre-school teachers’ high perceived control was related to high intentions to act in the event of child behaviour problems. Teachers’ high satisfaction with their work was also related to high perceive...
Peng, Haijun; Wang, Xinwei; Zhang, Sheng; Chen, Biaosong
2017-07-01
Nonlinear state-delayed optimal control problems have complex nonlinear characters. To solve this complex nonlinear problem, an iterative symplectic pseudospectral method based on quasilinearization techniques, the dual variational principle and pseudospectral methods is proposed in this paper. First, the proposed method transforms the original nonlinear optimal control problem into a series of linear quadratic optimal control problems. Then, a symplectic pseudospectral method is developed to solve these converted linear quadratic state-delayed optimal control problems. Coefficient matrices in the proposed method are sparse and symmetric since the dual variational principle is used, which makes the proposed method highly efficient. Converged numerical solutions with high precision can be obtained after a few iterations due to the benefit of the local pseudospectral method and quasilinearization techniques. In the numerical simulations, other numerical methods were used for comparisons. The numerical simulation results show that the proposed method is highly accurate, efficient and robust.
Swamp Buffalo in South Kalimantan : Problem, Disease and Control
Directory of Open Access Journals (Sweden)
Lily Natalia
2006-12-01
Full Text Available In recent years, several studies have been carried out to evaluate and investigate the important diseases of swamp buffaloes (Bubalus carabanensis in Kalimantan . More attention has been focused on the case of acute infectious diseases and sudden death in the buffaloes . Fasciolosis black disease, acute enteritis, especially fatal enterotoxaemia haemorrhagic septicaemia . and trypanosomiasis (Surra, are some of the important diseases found in these animals . Black disease caused by toxigenic Clostridium novyi occurs in the presence of the organism in the liver and the degree of liver fluke Fasciola gigantica infestation . In regions where black disease is enzootic, Cl. novvi can be isolated from livers of normal healthy animals . In Hulu Sungai Utara district, South Kalimantan, the prevalence of fasciolosis caused by Fasciola gigantica in swamp buffalo was 77% in 1991 . A gross sudden change in diet due to seasonal changes could induce rumen and intestinal stasis, which provide a favourable environment for the rapid proliferation of commensal toxigenic Clostridium perfringens in the small intestine . Subsequent absorption of the toxin produced through the gut wall and its generalized dissemination culminated in a fatal enterotoxaemia . Haemorrhagic septicaemia (HS is an acute, fatal disease affecting swamp buffalo, and caused by Pasteurella multocida B : 2 . The swamp buffalo is particularly susceptible for HS, and the reported greatest losses of swamp buffalo in Kalimantan due to HS is recorded in 1980s. The clinical signs of Surra in swamp buffalo were also found in certain areas in Danau Panggang area . Hulu Sungai Utara district . Vaccination is the accepted method for controlling Black disease, enterotoxaemia and HS. Multi component vaccine, alum adjuvant containing at least 5 types of clostridial toxoids and P. multocida B2 bacterin have been used and provide good protection to the animals . Control and treatment of liver fluke infestation
[Problems of prevention and control of poliomyelitis in Poland].
Mazurowska-Magdzik, Wiesława; Bucholc, Bozenna; Janaszek-Seydlitz, Wiesława; Szkoda, Tomasz; Magdzik, Wiesław
2010-01-01
In the fifties and the sixties of 20th century big epidemic and increasing numbers of poliomyelitis cases were observed in Poland as well in other countries of Europe and world. Inactivated Salk's vaccine in injections as well as oral attenuated vaccine were introduced to the control and prevention of this disease. As the result of it poliomyelitis was eradicated in American, European and of West Pacific Region of WHO. Since 1984 poliomyelitis cases were not registered in Poland, VAPP were observed in small numbers. Just now new vaccines with poliomyelitis component as Boostrix Polio and Adacel Polio are convenient to use as booster doses of poliomyelitis vaccine. Actually inactivated polio vaccine is used in majority of west European countries, USA, Canada, Australia. Inactivated vaccine in basic and attenuated vaccine in booster doses were used in Central and East European countries and only attenuated vaccine are used in big African, South and Central American countries, China, India and countries, witch were the part of past Soviet Union.
Mabbe, Elien; Soenens, Bart; Vansteenkiste, Maarten; Van Leeuwen, Karla
2016-06-01
This research examined whether and how adolescents' personality traits moderate associations between psychologically controlling parenting and problem behaviors. On the basis of self-determination theory, we also examined the mediating role of psychological need frustration in the effects of psychologically controlling parenting. A cross-sectional study in two samples (N = 423 and 292; Mage = 12.43 and 15.74 years) was conducted. While in Sample 1 both mothers and adolescents provided reports of parenting and problem behavior, Sample 2 relied on adolescent-reported parenting and mother-reported problem behavior. Psychologically controlling parenting was related to internalizing and externalizing problems in both samples. Little systematic evidence was obtained for the moderating role of personality, with the exception of a moderating effect of Agreeableness. In both samples, psychological control was unrelated to externalizing problems among adolescents high on Agreeableness. Analyses of Sample 2 showed that associations between psychological control and problem behavior were mediated by psychological need frustration. Adolescent personality plays a modest role as a moderator of associations between psychologically controlling parenting and problem behavior. Frustration of adolescents' basic and universal psychological needs can account for the undermining effects of psychologically controlling parenting. Directions for future research are discussed.
2015-05-01
FINAL REPORT Improved Understanding of Permafrost Controls on Hydrology in Interior Alaska by Integration of Ground-Based Geophysical...From - To) 03-2010 to 04-2015 4. TITLE AND SUBTITLE Improved Understanding of Permafrost Controls on Hydrology in Interior Alaska by...interior Alaska; hence frozen ground affects water resources, ecosystem state, landscape evolution, and soil stability. Despite its hydrologic
Institute of Scientific and Technical Information of China (English)
DENG Shu-xian; DING Yu; GE Lei
2008-01-01
We usually describle a comparatively more complex control system, especially a multi-inputs and multioutputs system by time domation analytical procedure. While the system's controllability means whether the system is controllable according to certain requirements. It involves not only the system's outputs' controllability but also the controllability of the system's partial or total conditions. The movement is described by difference equation in the linear discrete-time system. Therefore, the problem of controllability of the linear discrete-time system has been converted into a problem of the controllability of discrete-time difference equation. The thesis makes out the determination method of the discrete-time system's controllability and puts forward the sufficient and necessary conditions to determine it's controllability by making a study on the controllability of the linear discrete-time equation.
Singular linear quadratic control problem for systems with linear and constant delay
Sesekin, A. N.; Andreeva, I. Yu.; Shlyakhov, A. S.
2016-12-01
This article is devoted to the singular linear-quadratic optimization problem on the trajectories of the linear non-autonomous system of differential equations with linear and constant delay. It should be noted that such task does not solve the class of integrable controls, so to ensure the existence of a solution is needed to expand the class of controls to include the control impulse components. For the problem under consideration, we have built program control containing impulse components in the initial and final moments time. This is done under certain assumptions on the functional and the right side of the control system.
Low-Cost Control Problems on Perforated and Non-Perforated Domains
Indian Academy of Sciences (India)
S Kesavan; T Muthukumar
2008-02-01
We study the homogenization of a class of optimal control problems whose state equations are given by second order elliptic boundary value problems with oscillating coefficients posed on perforated and non-perforated domains. We attempt to describe the limit problem when the cost of the control is also of the same order as that describing the oscillations of the coefficients. We study the situations where the control and the state are both defined over the entire domain or when both are defined on the boundary.
Control design for the nonlinear benchmark problem via the output regulation method
Institute of Scientific and Technical Information of China (English)
Jie HUANG; Guoqiang HU
2004-01-01
The problem of designing a feedback controller to achieve asymptotic disturbance rejection / attenuation while maintaining good transient response in the RTAC system is known as a benchmark nonlinear control problem, which has been an intensive research subject since 1995. In this paper, we will further investigate the solvability of the robust disturbance rejection problem of the RTAC system by the measurement output feedback control based on the robust output regulation method. We have obtained a design by overcoming two major obstacles: find a closed-form solution of the regulator equations; and devise a nonlinear internal model to account for non-polynomial nonlinearities.
Directory of Open Access Journals (Sweden)
Gulbe Linda
2016-12-01
Full Text Available Geometrical accuracy of remote sensing data often is ensured by geometrical transforms based on Ground Control Points (GCPs. Manual selection of GCP is a time-consuming process, which requires some sort of automation. Therefore, the aim of this study is to present and evaluate methodology for easier, semi-automatic selection of ground control points for urban areas. Custom line scanning algorithm was implemented and applied to data in order to extract potential GCPs for an image analyst. The proposed method was tested for classical orthorectification and special object polygon transform. Results are convincing and show that in the test case semi-automatic methodology is able to correct locations of 70 % (thermal data – 80 % (orthophoto images of buildings. Geometrical transform for subimages of approximately 3 hectares with approximately 12 automatically found GCPs resulted in RSME approximately 1 meter with standard deviation of 1.2 meters.
Spent coffee grounds as air-propelled abrasive grit for weed control
Spent coffee grounds (SCG) represent a significant food waste residue. Value-added uses for this material would be beneficial. Gritty agricultural residues, such as corncob grit, can be employed as abrasive air-propelled agents for organically-compatible postemergence shredding of weed seedlings sel...
Directory of Open Access Journals (Sweden)
Arakelyan Sh. Kh.
2015-09-01
Full Text Available We suggest to apply the Bubnov–Galerkin procedure to solve scanning control problems for systems with distributed parameters. The algorithm is described in details for three-dimensional linear heat equation It allows to reduce the solution of control problem to finite-dimensional nonlinear moments problem. The procedure of derivation of moments problem is illustrated in details on the example of one-dimensional equation of thermal conductivity. The solution of obtained moments problem is found in a particular case. Based on obtained results a computer simulation is done using COMSOL Multiphysics platform in one-dimensional case for a rod. The main dependences of control function against input data of the problem are revealed. The state of the rod for several (constant values of the source intensity is expressed in terms of graphs and illustrations. Corresponding illustrations are brought in case of control absence (null-power source for comparison. An effective numerical scheme for solving the obtained system of nonlinear constraints is suggested in the case of extended class of admissible controls. Calculation of control parameters is reduced to the simplest problem of nonlinear programming.
A probabilistic solution of robust H∞ control problem with scaled matrices
Xie, R.; Gong, J. Y.
2016-07-01
This paper addresses the robust H∞ control problem with scaled matrices. It is difficult to find a global optimal solution for this non-convex optimisation problem. A probabilistic solution, which can achieve globally optimal robust performance within any pre-specified tolerance, is obtained by using the proposed method based on randomised algorithm. In the proposed method, the scaled H∞ control problem is divided into two parts: (1) assume the scaled matrices be random variables, the scaled H∞ control problem is converted to a convex optimisation problem for the fixed sample of the scaled matrix and a optimal solution corresponding to the fixed sample is obtained; (2) a probabilistic optimal solution is obtained by using the randomised algorithm based on a finite number N optimal solutions, which are obtained in part (1). The analysis shows that the worst case complexity of proposed method is a polynomial.
Dynamic programming for infinite horizon boundary control problems of PDE's with age structure
Faggian, Silvia
2008-01-01
We develop the dynamic programming approach for a family of infinite horizon boundary control problems with linear state equation and convex cost. We prove that the value function of the problem is the unique regular solution of the associated stationary Hamilton--Jacobi--Bellman equation and use this to prove existence and uniqueness of feedback controls. The idea of studying this kind of problem comes from economic applications, in particular from models of optimal investment with vintage capital. Such family of problems has already been studied in the finite horizon case by Faggian. The infinite horizon case is more difficult to treat and it is more interesting from the point of view of economic applications, where what mainly matters is the behavior of optimal trajectories and controls in the long run. The study of infinite horizon is here performed through a nontrivial limiting procedure from the corresponding finite horizon problem.
A Study on the Fracture Control of Rock Bolts in High Ground Pressure Roadways of Deep Mines
Directory of Open Access Journals (Sweden)
Wen Jinglin
2015-01-01
Full Text Available According to the frequent fractures of rock bolts in high ground pressure roadways of deep mines, this paper analyzes the mechanism of fractures and concludes that high ground pressure and material de-fects are main reasons for the fracture of rock bolts. The basic idea of fracture control of rock bolts in high ground pressure roadways of deep mines is to increase the yield load and the limit load of rock bolt materials and reduce the actual load of rock bolts. There are four ways of controlling rock bolt fracture: increasing the rock bolt diameter, strengthening bolt materials, weakening support rigidity and the implementation of double supporting. With the roadway support of the 2302 working face of a coal mine as the project background, this paper carries out a study on the effect of two schemes, increasing the rock bolt diameter and the double supporting technique through methods of theoretical analysis, numerical simulation and so on. It determines the most reasonable diam-eter of rock bolts and the best delay distance of secondary support. Practices indicate that rock bolt fracture can be effectively controlled through the double supporting technique, which strengthens the roof and two sides through the first supporting technique and strengthens side angles through the secondary supporting technique.
Rozenfeld, Pawel; Kuga, Helio Koiti; Orlando, Valcir
An international symposium on spacecraft flight dynamics and ground control systems produced 85 papers in the areas of attitude determination and control, orbit control, satellite constellation strategies, stationkeeping, spacecraft maneuvering, orbit determination, astrodynamics, ground command and control systems, and mission operations. Several papers included discussions on the application of artificial intelligence, neural networks, expert systems, and ion propulsion. For individual titles, see A95-89098 through A95-89182.
Institute of Scientific and Technical Information of China (English)
尹鹏; 李满天; 王俊; 查富生; 孙立宁
2015-01-01
The performance of legged hopping robot is subjected to the influence of the ground stiffness feature during the contact phase.To avoid the influence and insulate the ground stiffness disturbance we first established the simplified single leg hopping model with elastic featured ground,then an analysis about the relation of ground stiffness with moving trajectory and contact force profile is made.Based on this a control strategy to utilized to compensate the ground contact force to be the same as that of an undisturbed system via active extension or retraction of the leg during contact.The validity is demonstrated by simulation result.%为了使足式弹跳机器人在运动中避免由于地面接触刚度的变化对弹跳运动产生的影响，首先建立了单足弹跳机器人在弹性地面条件下的运动简化模型，进而分析了地面弹簧刚度变化对机体重心运动轨迹以及着地相中足地接触力的影响。采用足地接触力补偿控制的手段，通过主动控制单腿的伸缩，使模型中弹簧系统的足力输出与期望保持一致，消除了地面刚度变化对机体运动的干扰。利用仿真实验表明了控制方法的可行性。
A multi-step method for partial eigenvalue assignment problem of high order control systems
Liu, Hao; Xu, Jiajia
2017-09-01
In this paper, we consider the partial eigenvalue assignment problem of high order control systems. Based on the orthogonality relations, we propose a new method for solving this problem by which the undesired eigenvalues are moved to desired values and keep the remaining eigenvalues unchanged. Using the inverse of Cauchy matrix, we give the solvable condition and the explicit solutions to this problem. Numerical examples show that our method is effective.
A numerical method for solving optimal control problems using state parametrization
Mehne, H.; Borzabadi, A.
2006-06-01
A numerical method for solving a special class of optimal control problems is given. The solution is based on state parametrization as a polynomial with unknown coefficients. This converts the problem to a non-linear optimization problem. To facilitate the computation of optimal coefficients, an improved iterative method is suggested. Convergence of this iterative method and its implementation for numerical examples are also given.
Citrus Quality Control: An NMR/MRI Problem-Based Experiment
Erhart, Sarah E.; McCarrick, Robert M.; Lorigan, Gary A.; Yezierski, Ellen J.
2016-01-01
An experiment seated in an industrial context can provide an engaging framework and unique learning opportunity for an upper-division physical chemistry laboratory. An experiment that teaches NMR/MRI through a problem-based quality control of citrus products was developed. In this experiment, using a problem-based learning (PBL) approach, students…
Cognitive-Behavioral Training of Problem-Solving and Impulse-Control with Delinquent Adolescents.
Hains, Anthony A.; Hains, Ann Higgins
1988-01-01
Examined cognitive-behavioral training procedures designed to enhance social problem-solving and impulse-control skills of delinquent adolescents. Explored multiple baseline design across subjects and tasks and an alternating-treatments design. Presented two different forms of hypothetical social problems to subjects (N=5). Results indicated…
Directory of Open Access Journals (Sweden)
Jingtao Shi
2013-01-01
Full Text Available This paper is concerned with the relationship between maximum principle and dynamic programming for stochastic recursive optimal control problems. Under certain differentiability conditions, relations among the adjoint processes, the generalized Hamiltonian function, and the value function are given. A linear quadratic recursive utility portfolio optimization problem in the financial engineering is discussed as an explicitly illustrated example of the main result.
Health and Sleep Problems in Cornelia de Lange Syndrome: A Case Control Study
Hall, S. S.; Arron, K.; Sloneem, J.; Oliver, C.
2008-01-01
Background: Self-injury, sleep problems and health problems are commonly reported in Cornelia de Lange Syndrome (CdLS) but there are no comparisons with appropriately matched participants. The relationship between these areas and comparison to a control group is warranted. Method: 54 individuals with CdLS were compared with 46 participants with…
Linearization of a Matrix Riccati Equation Associated to an Optimal Control Problem
Directory of Open Access Journals (Sweden)
Foued Zitouni
2014-01-01
Full Text Available The matrix Riccati equation that must be solved to obtain the solution to stochastic optimal control problems known as LQG homing is linearized for a class of processes. The results generalize a theorem proved by Whittle and the one-dimensional case already considered by the authors. A particular two-dimensional problem is solved explicitly.
Neidert, Pamela L.; Iwata, Brian A.; Dozier, Claudia L.
2005-01-01
We describe the assessment and treatment of 2 children with autism spectrum disorder whose problem behaviors (self-injury, aggression, and disruption) were multiply controlled. Results of functional analyses indicated that the children's problem behaviors were maintained by both positive reinforcement (attention) and negative reinforcement (escape…
A Hamiltonian-based solution to the linear quadratic consensus control problem
Weiss, M.
2012-01-01
The Linear Quadratic Consensus Control (LQCC) problem is a relaxation of the classical Linear Quadratic Regulation (LQR) problem, that consists of asymptotically driving the state of the system to a "consensus" point in which all coordinates are equal, in such a way that a quadratic cost function on
On the Riccati Equations of the H∞ Control Problem for Discrete Time-Varying Systems
Verhaegen, Michel; Scherpen, Jacquelien M.A.; Benedetto, Maria Domenica Di; Bittanti, Sergio; Isidori, Alberto; Luca, Alessandro De; Mosca, Edoardo; Oriolo, Giuseppe
1995-01-01
In this paper we investigate the relationship between the different Riccati equations that appear in the H∞ control problem for linear discrete time-varying systems. Once we obtain this relation we can reformulate the conditions under which the H∞ output feedback problem is solvable. In contrary to
Linear discrete-time Pareto-Nash-Stackelberg control problem and principles for its solving
Directory of Open Access Journals (Sweden)
Valeriu Ungureanu
2013-04-01
Full Text Available A direct-straightforward method for solving linear discrete-time optimal control problem is applied to solve control problem of a linear discrete-time system as a mixture of multi-criteria Stackelberg and Nash games. For simplicity, the exposure starts with the simplest case of linear discrete-time optimal control problem and, by sequential considering of more general cases, investigation finalizes with the highlighted Pareto-Nash-Stackelberg and set valued control problems. Different principles of solving are compared and their equivalence is proved. Mathematics Subject Classification 2010: 49K21, 49N05, 93C05, 93C55, 90C05, 90C29, 91A10, 91A20, 91A44, 91A50.
Visual Problem Solving and Self‐regulation in Training Air Traffic Control
Meeuwen van, Ludo
2015-01-01
Van Meeuwen, L. W. (2013). Visual problem solving and self-regulation in training air traffic control (Unpublished doctoral dissertation). Centre for Learning Sciences and Technologies, Open Universiteit, Heerlen, The Netherlands.
Visual problem solving and self-regulation in training air traffic control
Van Meeuwen, Ludo
2013-01-01
Van Meeuwen, L. W. (2013). Visual problem solving and self-regulation in training air traffic control (Unpublished doctoral dissertation). Centre for Learning Sciences and Technologies, Open Universiteit, Heerlen, The Netherlands.
On the Limit Matrix Obtained in the Homogenization of an Optimal Control Problem
Indian Academy of Sciences (India)
S Kesavan; M Rajesh
2002-05-01
A new formulation for the limit matrix occurring in the cost functional of an optimal control problem on homogenization is obtained. It is used to obtain an upper bound for this matrix (in the sense of positive definite matrices).
Pieper, M.J.; Francke, A.L.; Steen, J.T. van der; Scherder, E.J.; Twisk, J.W.R.; Kovach, C.R.; Achterberg, W.P.
2016-01-01
OBJECTIVE: To investigate whether implementation of a stepwise multidisciplinary intervention ('STA OP!' ['STAND UP!']) is effective in reducing behavioural problems and depressive symptoms in nursing home residents with advanced dementia. DESIGN: Cluster randomised controlled trial. METHOD: We
SYMBOLIC ALGEBRAIC MANIPULATION BY DIGITAL COMPUTER IN PROBLEMS OF CONTROL THEORY.
shown, using a FORMAC program. The advantages over the conventional root locus method are discussed. Areas of possible future use of FORMAC in algebraic problems of control theory are discussed. (Author)
Visual problem solving and self-regulation in training air traffic control
Van Meeuwen, Ludo
2013-01-01
Van Meeuwen, L. W. (2013). Visual problem solving and self-regulation in training air traffic control (Unpublished doctoral dissertation). Centre for Learning Sciences and Technologies, Open Universiteit, Heerlen, The Netherlands.
Visual Problem Solving and Self‐regulation in Training Air Traffic Control
Meeuwen van, Ludo
2015-01-01
Van Meeuwen, L. W. (2013). Visual problem solving and self-regulation in training air traffic control (Unpublished doctoral dissertation). Centre for Learning Sciences and Technologies, Open Universiteit, Heerlen, The Netherlands.
A Boundary Control Problem for the Viscous Cahn–Hilliard Equation with Dynamic Boundary Conditions
Energy Technology Data Exchange (ETDEWEB)
Colli, Pierluigi, E-mail: pierluigi.colli@unipv.it; Gilardi, Gianni, E-mail: gianni.gilardi@unipv.it [Universitá di Pavia and Research Associate at the IMATI – C.N.R. PAVIA, Dipartimento di Matematica “F. Casorati” (Italy); Sprekels, Jürgen, E-mail: juergen.sprekels@wias-berlin.de [Weierstrass Institute (Germany)
2016-04-15
A boundary control problem for the viscous Cahn–Hilliard equations with possibly singular potentials and dynamic boundary conditions is studied and first order necessary conditions for optimality are proved.
Kuyk, E.M. van; Wissink-Essink, M.; Brugman-Boezeman, A.T.M.; Oerlemans, H.M.; Nijhuis-Van der Sanden, M.W.G.; Severijnen, R.S.V.M.; Festen, C.; Bleijenberg, G.
2001-01-01
BACKGROUND/PURPOSE: The most frequent consequences of being born with an anorectal malformation (ARM) are problems with fecal continence and constipation, which can have various negative implications. In this prospective, controlled study the effect of multidisciplinary behavioral treatment dealing
Directory of Open Access Journals (Sweden)
Camila Pereira Pinto
2015-06-01
Full Text Available In a highly competitive market, companies need increasingly skilled human resources, especially when it comes to engineering. Universities, therefore, play an important role in this scenario, while training future professionals of the country. However, in this task, the institutions are faced with the challenge of attracting and working with young people of Generation Y, which have characteristics and needs that are not met by traditional teaching methods. Problem-Based Learning (PBL is an approach evolved in order to study and develop educational alternatives that meet the needs of businesses as well as the new student profile. In addition, actively teaching is not a simple task and becomes more complex when it refers to assess the knowledge gained through this method. Thus, this paper presents the planning, implementation and the assessment method adopted in a course of Industrial Engineering at the Federal University of Itajubá based on PBL. For this study it was adopted the action research method, in which the authors actively participated in all stages of the course, acting as facilitators in the course planning, implementation and monitoring. As a result, it is highlighted in this article, the benefits achieved by all involved through active learning, as well as the strengths and weaknesses of the method. Moreover, improvements are proposed for future courses.
Directory of Open Access Journals (Sweden)
Anna F. Kochkina
2015-12-01
Full Text Available The article investigates the problems of restoration and attribution of leather footwear from the Malaya Ryazan burial ground of the Golden Horde time on the Samarskаya Luka. It contains a detailed description of the main stages in restoration of archaeological leather items, overview of leather structure, chemical processes it is exposed to during archaeologization. The authors focus on study of funerary footwear from Malaya Ryazan burial ground. Male grave no. 131, by Christian rite, contained a pair of leather shoes, which was preliminarily attributed as funerary footwear. The find was then subjected to restoration. The study showed that the shoes were made of cattle hide. Due to incomplete plasticization of the leather, the restorers decided to reconstruct the cut without completely reconstructing its form. The remaining seams and sections helped recreate what was supposed to be the original cut of the shoes. The restored leather was superimposed on the duplicating material corresponding to the shape of the pattern. The study of footwear has not given any evidence of intravital usage, i.e. the shoes were made especially for the funeral. Similar ritual footwear can be correlated with the kaliga mentioned in written sources.
Locus of control, problem-solving skills appraisal as predictors of waste prevention behaviors
Karbalaei, S.; Abdollahi, A.; Talib, M.A.; Yaacob, S.N.; Ismail, Z.
2013-01-01
Given that waste generation is a devastating problem, it is necessary that we advance our knowledge about the etiology of waste prevention behaviors. Accordingly, this study sought to increase the existing literature of waste prevention behaviors by examining the relationships among the locus of control, problem-solving confidence, approach-avoidance style, personal control style and participant’s age with waste prevention behaviors. Two hundred and forty participants (126 Women, and 114 men)...
A MATLAB GUI for a Legendre Pseudospectral algorithm for optimal control problems
Hall, Andrew O.
1999-01-01
Approved for public release; distribution is unlimited This implementation of a Legendre-Gauss-Lobatto Pseudospectral (LGLP) algorithm takes advantage of the MATLAB Graphical User Interface (GUI) and the Optimization Toolbox to allow an efficient implementation of a direct solution technique. Direct solutions techniques solve optimal control problems without solving for the optimality conditions. Using the LGLP method, an optimal control problem is discretized into a Nonlinear Program (NLP...
The First Survey for Abilities of Wavelets in Solving Optimal Control Problems by Embedding Methods
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A. Fakharzadeh
2007-06-01
Full Text Available By a brief review on the applications of wavelets in solving optimal control problems, a multiresolution analysis for two dimensional Sobolev spaces and the square spline wavelets are considered. Regarding the density and approximation properties of these wavelets, for the first time, they are employed for solving optimal control problems by embedding method. Existence and the determination way for the solution are also discussed. Finally, the abilities of the new approach are explained by a numerical example and some comparisons
Mehmetoglu, Mustafa; Akyol, Emrah; Rose, Kenneth
2016-01-01
This note studies the global optimization of controller mappings in discrete-time stochastic control problems including Witsenhausen's celebrated 1968 counter-example. We propose a generally applicable non-convex numerical optimization method based on the concept of deterministic annealing-which is derived from information-theoretic principles and was successfully employed in several problems including vector quantization, classification, and regression. We present comparative numerical resul...
Dynamics and control of motion on the ground and in the air with application to biped robots
Hemami, H.; Zheng, Y.-F.
The dynamics of a multi-linkage model of natural or man-made systems with arbitrary holonomic and non-holonomic constraints at the joints are formulated. The formulation is equally applicable to movements on the ground or in the air. Nonlinear control strategies for postural balance and rhythmic motion are presented. A predictive algorithm to compensate for computation or transmission delay is proposed. Digital computer simulations are presented to demonstrate the effectiveness of the control strategy for a five-link three-dimensional biped.
Matviychuk, Oksana G.
2012-11-01
The paper deals with the state estimation problem for the linear control system containing impulsive control terms (or measures). The problem is studied here under uncertainty conditions when the initial system state is unknown but bounded, with given bound. It is assumed also that the system states should belong to the given ellipsoid in the state space. So the main problem of estimating the reachable set of the control system is studied here under more complicated assumption related to the case of state constraints. It is assumed additionally that impulsive controls in the dynamical system must belong to the intersection of a special cone with a generalized ellipsoid both taken in the space of functions of bounded variation. The last constraint is motivated by problems of impulsive control theory and by models from applied areas when not every direction of control impulses is acceptable in the system. We present here the state estimation algorithms that use the special structure of the control system and take into account additional restrictions on states and controls. The algorithms are based on ellipsoidal techniques for estimating the trajectory tubes of uncertain dynamical systems. Numerical simulation results related to proposed procedures are also given.
2015-04-24
be an adequate interpretation in certain applications such as small ground robots . However, for the AGVs that are at least the size of a passenger... problematic , because the OCP solver requires all functions to be twice continuously differentiable. To address this challenge, the safe region is...avoidance for manipulators and mobile robots ,” International Journal of Robotics Research, vol. 5, pp. 90-98, 1986. [4] S. Shimoda, Y. Kuroda, and K
New age control on a mid-shelf grounding event in Eastern Basin, Ross Sea
Cone, A. N.; Bart, P. J.
2009-12-01
It is widely accepted that the West Antarctic Ice Sheet (WAIS) was grounded at the continental shelf edge in the eastern Ross Sea during the Last Glacial Maximum (LGM), but the precise chronology is debated. Post-LGM ice retreat chronologies have been developed using radiocarbon dating, mainly of acid-insoluble organics (AIO). Foraminifer tests yield more accurate radiocarbon dates than AIO because forams are less likely to be contaminated by allochthonous carbon, but unfortunately forams are sparse in Antarctic marine sediment cores. Here we show four consistent radiocarbon dates from forams in cored intervals within the foreset of a mid-continental-shelf grounding-zone wedge in Eastern Basin, Ross Sea. Our new radiocarbon dates reveal that the WAIS was grounded on the mid continental shelf circa 32,000 14C yr B.P., suggesting that retreat from this position began more than 10,000 years prior to the maximum sea level fall and global cooling associated with LGM. The dates contradict previous studies, which concluded that the WAIS was at its maximum shelf edge extent during LGM.
Wildman, R.A.; Domagalski, J.L.; Hering, J.G.
2009-01-01
The relative influences of hydrologic processes and biogeochemistry on the transport and retention of minor solutes were compared in the riverbed of the lower Merced River (California, USA). The subsurface of this reach receives ground water discharge and surface water infiltration due to an altered hydraulic setting resulting from agricultural irrigation. Filtered ground water samples were collected from 30 drive point locations in March, June, and October 2004. Hydrologic processes, described previously, were verified by observations of bromine concentrations; manganese was used to indicate redox conditions. The separate responses of the minor solutes strontium, barium, uranium, and phosphorus to these influences were examined. Correlation and principal component analyses indicate that hydrologic processes dominate the distribution of trace elements in the ground water. Redox conditions appear to be independent of hydrologic processes and account for most of the remaining data variability. With some variability, major processes are consistent in two sampling transects separated by 100 m. Copyright ?? 2009 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.
The solution of singular optimal control problems using direct collocation and nonlinear programming
Downey, James R.; Conway, Bruce A.
1992-08-01
This paper describes work on the determination of optimal rocket trajectories which may include singular arcs. In recent years direct collocation and nonlinear programming has proven to be a powerful method for solving optimal control problems. Difficulties in the application of this method can occur if the problem is singular. Techniques exist for solving singular problems indirectly using the associated adjoint formulation. Unfortunately, the adjoints are not a part of the direct formulation. It is shown how adjoint information can be obtained from the direct method to allow the solution of singular problems.
DEFF Research Database (Denmark)
Evgrafov, Anton; Gregersen, Misha Marie; Sørensen, Mads Peter
2011-01-01
design, in particular shape and topology optimization, and are most often solved numerically utilizing a finite element approach. Within the FV framework for control in the coefficients problems the main difficulty we face is the need to analyze the convergence of fluxes defined on the faces of cells......We present a convergence analysis of a cell-based finite volume (FV) discretization scheme applied to a problem of control in the coefficients of a generalized Laplace equation modelling, for example, a steady state heat conduction. Such problems arise in applications dealing with geometric optimal...
Pettit, G S; Laird, R D; Dodge, K A; Bates, J E; Criss, M M
2001-01-01
The early childhood antecedents and behavior-problem correlates of monitoring and psychological control were examined in this prospective, longitudinal, multi-informant study. Parenting data were collected during home visit interviews with 440 mothers and their 13-year-old children. Behavior problems (anxiety/depression and delinquent behavior) were assessed via mother, teacher, and/or adolescent reports at ages 8 through 10 years and again at ages 13 through 14. Home-interview data collected at age 5 years were used to measure antecedent parenting (harsh/reactive, positive/proactive), family background (e.g., socioeconomic status), and mother-rated child behavior problems. Consistent with expectation, monitoring was anteceded by a proactive parenting style and by advantageous family-ecological characteristics, and psychological control was anteceded by harsh parenting and by mothers' earlier reports of child externalizing problems. Consistent with prior research, monitoring was associated with fewer delinquent behavior problems. Links between psychological control and adjustment were more complex: High levels of psychological control were associated with more delinquent problems for girls and for teens who were low in preadolescent delinquent problems, and with more anxiety/depression for girls and for teens who were high in preadolescent anxiety/depression.
Locus of control, problem-solving skills appraisal as predictors of waste prevention behaviors
Directory of Open Access Journals (Sweden)
Karbalaei, S.
2013-12-01
Full Text Available Given that waste generation is a devastating problem, it is necessary that we advance our knowledge about the etiology of waste prevention behaviors. Accordingly, this study sought to increase the existing literature of waste prevention behaviors by examining the relationships among the locus of control, problem-solving confidence, approach-avoidance style, personal control style and participant’s age with waste prevention behaviors. Two hundred and forty participants (126 Women, and 114 men from Putra University (Universiti Putra Malaysia completed the Locus of Control of Behavior Scale, Waste Prevention Behaviors, Problem-Solving skills Appraisal and Socio-demographic questions. The Structural Equation Modeling (SEM estimated individuals with internal personal control, effective problem-solving confidence, internal locus of control and approaching styles were more likely to pursue waste prevention behaviors. In addition, men were better than women at problem-solving confidence, approaching style, while women were better than men at internal locus of control, and personal control style. Therefore, these findings reinforce the importance of personality traits in waste prevention behaviors.
Construction of asymptotically optimal control for crisscross network from a free boundary problem
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Amarjit Budhiraja
2016-12-01
Full Text Available An asymptotic framework for optimal control of multiclass stochastic processing networks, using formal diffusion approximations under suitable temporal and spatial scaling, by Brownian control problems (BCP and their equivalent workload formulations (EWF, has been developed by Harrison (1988. This framework has been implemented in many works for constructing asymptotically optimal control policies for a broad range of stochastic network models. To date all asymptotic optimality results for such networks correspond to settings where the solution of the EWF is a reflected Brownian motion in $\\mathbb{R} _{+}$ or a wedge in $\\mathbb{R} _{+}^{2}$. In this work we consider a well studied stochastic network which is perhaps the simplest example of a model with more than one dimensional workload process. In the regime considered here, the singular control problem corresponding to the EWF does not have a simple form explicit solution. However, by considering an associated free boundary problem one can give a representation for an optimal controlled process as a two dimensional reflected Brownian motion in a Lipschitz domain whose boundary is determined by the solution of the free boundary problem. Using the form of the optimal solution we propose a sequence of control policies, given in terms of suitable thresholds, for the scaled stochastic network control problems and prove that this sequence of policies is asymptotically optimal. As suggested by the solution of the EWF, the policy we propose requires a server to idle under certain conditions which are specified in terms of thresholds determined from the free boundary.
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Eko Sujadi
2016-03-01
Full Text Available Problem focused coping need to be possessed by every individual. The purposes of this research were to described locus of control, the effectiveness of interpersonal communication, problem focused coping,the correlation between locus of control with problem focused coping, andthe correlationbetween the effectiveness of interpersonal communication with problem focused coping.This research was descriptive & correlation research by using quantitative approach. Data were collected through a Likert scale questionaire and locus of controlby using inventory Rotters Internal-External Locus of Control (I-E Scale, which was the validity and reliability has been tested. The data were analyzed by percentage technique and product moment correlation. The finding of research are: 1locus of control were in the middle range between internal locus of control and external locus of control with an average as big as 11.46, 2 the general level of effectiveness of interpersonal communication is in high category, 3 the general level of problem focused coping is in high category, 4 there is correlation between locus of control withproblem focused coping, and 5 there is correlation betweeneffectiveness of interpersonal communicationwithproblem focused coping.
Gregory, L; Yoshihara, E; Ribeiro, B L M; Silva, L K F; Marques, E C; Meira, E B S; Rossi, R S; Sampaio, P H; Louvandini, H; Hasegawa, M Y
2015-12-01
To evaluate the anthelmintic effect of Musa spp. leaves, 12 animals were artificially infected with Haemonchus contortus, and another 12 animals were infected with Trichostrongylus colubriformis. Then, both treatment groups were offered 400 g of dried ground banana plant leaves, and the control animals were offered only 1000 g of coast cross hay. During the trials, the animals received weekly physical examinations. The methods used to evaluate the efficiency of this treatment were packed cell volume, total plasma protein and faecal egg counts, and egg hatchability tests were performed on days -2, +3, +6, +9, +13 and +15. Coproculture tests were performed on day -2 to confirm monospecific infections. In the FEC and EHT, a statistically significant difference (0.04, 0.005; p 0.05) for Haemochus contortus group in all tests. Our results confirmed previous findings suggesting that dried ground banana plant leaves possess anthelmintic activity.
Directory of Open Access Journals (Sweden)
X. J. Guan
2010-07-01
Full Text Available The companion paper (Guan et al., 2010 demonstrated variable interactions and correlations between shallow soil moisture and ground thaw in soil filled areas along a wetness spectrum in a subarctic Canadian Precambrian Shield landscape. From wetter to drier, these included a wetland, peatland and soil filled valley. Herein, water and energy fluxes were examined for these same subarctic study sites to discern the key controlling processes on the found patterns. Results showed the presence of surface water was the key control in variable soil moisture and frost table interactions among sites. At the peatland and wetland sites, accumulated water in depressions and flow paths maintained soil moisture for a longer duration than at the hummock tops. These wet areas were often locations of deepest thaw depth due to the transfer of latent heat accompanying lateral surface runoff. Although the peatland and wetland sites had large inundation extent, modified Péclet numbers indicated the relative influence of external and internal hydrological and energy processes at each site were different. Continuous inflow from an upstream lake into the wetland site caused advective and conductive thermal energies to be of equal importance to ground thaw. The absence of continuous surface flow at the peatland and valley sites led to dominance of conductive thermal energy over advective energy for ground thaw. The results suggest that the modified Péclet number could be a very useful parameter to differentiate landscape components in modeling frost table heterogeneity. The calculated water and energy fluxes, and the modified Péclet number provide quantitative explanations for the shallow soil moisture-ground thaw patterns by linking them with hydrological processes and hillslope storage capacity.
Directory of Open Access Journals (Sweden)
C. J. Westbrook
2010-01-01
Full Text Available The companion paper (Guan et al., 2010 demonstrated variable interactions and correlations between shallow soil moisture and ground thaw in soil filled areas along a wetness spectrum in a subarctic Canadian Precambrian Shield landscape. From wetter to drier, these included a wetland, peatland and soil filled valley. Herein, water and energy fluxes were examined for these same subarctic study sites to discern the key controlling processes on the found patterns. Results showed the key control in variable soil moisture and frost table interactions among the sites was the presence of surface water. At the peatland and wetland sites, accumulated water in depressions and flow paths maintained soil moisture for a longer duration than at the hummock tops. These wet areas were often locations of deepest thaw depth due to the transfer of latent heat accompanying lateral surface runoff. Although the peatland and wetland sites had large inundation extent, modified Péclet numbers indicated the relative influence of external and internal hydrological processes at each site were different. Continuous inflow from an upstream lake into the wetland site caused advective and conductive thermal energies to be of equal importance to conductive ground thaw. The absence of continuous surface flow at the peatland and valley sites led to dominance of conductive thermal energy over advective energy for ground thaw. The results suggest that the modified Péclet number could be a very useful parameter to differentiate landscape components in modeling frost table heterogeneity. The calculated water and energy fluxes, and the modified Péclet number provide quantitative explanations for the shallow soil moisture-ground thaw patterns by linking them with hydrological processes and hillslope storage capacity.
DEFF Research Database (Denmark)
Mariegaard, Jesper Sandvig
We consider a control problem for the wave equation: Given the initial state, find a specific boundary condition, called a control, that steers the system to a desired final state. The Hilbert uniqueness method (HUM) is a mathematical method for the solution of such control problems. It builds...... on the duality between the control system and its adjoint system, and these systems are connected via a so-called controllability operator. In this project, we are concerned with the numerical approximation of HUM control for the one-dimensional wave equation. We study two semi-discretizations of the wave...... equation: a linear finite element method (L-FEM) and a discontinuous Galerkin-FEM (DG-FEM). The controllability operator is discretized with both L-FEM and DG-FEM to obtain a HUM matrix. We show that formulating HUM in a sine basis is beneficial for several reasons: (i) separation of low and high frequency...
Geological Environment Problems Caused by Controlling Groundwater Exploitation in Jiangyin City
Institute of Scientific and Technical Information of China (English)
DENG Qing-hai; MA Feng-shan; YUAN Ren-mao; YAO Bing-kui
2007-01-01
Geological environment effects caused by the control of groundwater exploitation in Jiangyin city are discussed thoroughly, including the dynamic variation of groundwater levels and quality and the development of land subsidence and ground fissures. According to the dynamic characteristics of groundwater levels, some advice about groundwater exploitation is offered. Our research will provide a basis for using groundwater resources and the prevention of geological disasters in Jiangyin city and the Suzhou-Wuxi-Changzhou area. The following results are deduced from our research. First, groundwater levels vary with the exploitation of groundwater in Jiangyin city and are affected by hydrogeological conditions. The groundwater levels remained rather stable before and after the implementation of control of groundwater exploitation in the northwest of Jiangyin city along the Yangtze River. A suitable level of exploitation should be allowed. In the southeast, the speed of recovery of the groundwater level has been rather rapid after the control of exploitation. We conclude that groundwater might be exploited locally after the groundwater level has recovered. In the southwest, the speed of recovery of the groundwater level is rather slow and exploitation of groundwater should be prohibited. Second, groundwater quality is stable in Jiangyin city and the contents of the main chemical indices of groundwater varied only slightly before and after the control of exploitation. Third, after controlling the exploitation, the speed of land subsidence has clearly slowed down and the development of ground fissures has been controlled effectively.
Murphy, M. M.
2016-02-01
Ground control research in underground coal mines has been ongoing for over 50 years. One of the most problematic issues in underground coal mines is roof failures associated with weak shale. This paper will present a historical narrative on the research the National Institute for Occupational Safety and Health has conducted in relation to rock mechanics and shale. This paper begins by first discussing how shale is classified in relation to coal mining. Characterizing and planning for weak roof sequences is an important step in developing an engineering solution to prevent roof failures. Next, the failure mechanics associated with the weak characteristics of shale will be discussed. Understanding these failure mechanics also aids in applying the correct engineering solutions. The various solutions that have been implemented in the underground coal mining industry to control the different modes of failure will be summarized. Finally, a discussion on current and future research relating to rock mechanics and shale is presented. The overall goal of the paper is to share the collective ground control experience of controlling roof structures dominated by shale rock in underground coal mining.
Büskens, Christof; Maurer, Helmut
2000-08-01
Parametric nonlinear optimal control problems subject to control and state constraints are studied. Two discretization methods are discussed that transcribe optimal control problems into nonlinear programming problems for which SQP-methods provide efficient solution methods. It is shown that SQP-methods can be used also for a check of second-order sufficient conditions and for a postoptimal calculation of adjoint variables. In addition, SQP-methods lead to a robust computation of sensitivity differentials of optimal solutions with respect to perturbation parameters. Numerical sensitivity analysis is the basis for real-time control approximations of perturbed solutions which are obtained by evaluating a first-order Taylor expansion with respect to the parameter. The proposed numerical methods are illustrated by the optimal control of a low-thrust satellite transfer to geosynchronous orbit and a complex control problem from aquanautics. The examples illustrate the robustness, accuracy and efficiency of the proposed numerical algorithms.
Energy Technology Data Exchange (ETDEWEB)
Efroymson, Rebecca Ann [ORNL; Peterson, Mark J [ORNL; Jones, Daniel Steven [ORNL; Suter, Glenn [U.S. Environmental Protection Agency
2008-01-01
An ecological risk assessment was conducted at Yuma Proving Ground, Arizona, as a demonstration of the Military Ecological Risk Assessment Framework (MERAF). The focus of the assessment was a testing program at Cibola Range, which involved an Apache Longbow helicopter firing Hellfire missiles at moving targets, i.e., M60-A1 tanks. The problem formulation for the assessment included conceptual models for three component activities of the test, helicopter overflight, missile firing, and tracked vehicle movement, and two ecological endpoint entities, woody desert wash communities and desert mule deer (Odocoileus hemionus crooki) populations. An activity-specific risk assessment framework was available to provide guidance for assessing risks associated with aircraft overflights. Key environmental features of the study area include barren desert pavement and tree-lined desert washes. The primary stressors associated with helicopter overflights were sound and the view of the aircraft. The primary stressor associated with Hellfire missile firing was sound. The principal stressor associated with tracked vehicle movement was soil disturbance, and a resulting, secondary stressor was hydrological change. Water loss to washes and wash vegetation was expected to result from increased ponding, infiltrationand/or evaporation associated with disturbances to desert pavement. A plan for estimating integrated risks from the three military activities was included in the problem formulation.
A control problem for Burgers' equation with bounded input/output
Burns, John A.; Kang, Sungkwon
1990-01-01
A stabilization problem for Burgers' equation is considered. Using linearization, various controllers are constructed which minimize certain weighted energy functionals. These controllers produce the desired degree of stability for the closed-loop nonlinear system. A numerical scheme for computing the feedback gain functional is developed and several numerical experiments are performed to show the theoretical results.
On an Optimal -Control Problem in Coefficients for Linear Elliptic Variational Inequality
Directory of Open Access Journals (Sweden)
Olha P. Kupenko
2013-01-01
Full Text Available We consider optimal control problems for linear degenerate elliptic variational inequalities with homogeneous Dirichlet boundary conditions. We take the matrix-valued coefficients in the main part of the elliptic operator as controls in . Since the eigenvalues of such matrices may vanish and be unbounded in , it leads to the “noncoercivity trouble.” Using the concept of convergence in variable spaces and following the direct method in the calculus of variations, we establish the solvability of the optimal control problem in the class of the so-called -admissible solutions.
The Impact of Inattention and Emotional Problems on Cognitive Control in Primary School Children
DEFF Research Database (Denmark)
Sørensen, Lin; Plessen, Kerstin J; Lundervold, Astri J
2012-01-01
Objective: The present study investigated the predictive value of parent/teacher reports of inattention and emotional problems on cognitive control function in 241 children in primary school. Method: Cognitive control was measured by functions of set-shifting and working memory as assessed...... uniquely explained the variance on the Shift scale from the BRIEF. Conclusion: Valid information on cognitive control function in primary school children should thus include simultaneous information concerning problems of inattention and emotion. (J. of Att. Dis. 2011; XX(X) 1-XX)....
Directory of Open Access Journals (Sweden)
B. Kafash
2014-04-01
Full Text Available In this paper, we present a computational method for solving optimal control problems and the controlled Duffing oscillator. This method is based on state parametrization. In fact, the state variable is approximated by Boubaker polynomials with unknown coefficients. The equation of motion, performance index and boundary conditions are converted into some algebraic equations. Thus, an optimal control problem converts to a optimization problem, which can then be solved easily. By this method, the numerical value of the performance index is obtained. Also, the control and state variables can be approximated as functions of time. Convergence of the algorithms is proved. Numerical results are given for several test examples to demonstrate the applicability and efficiency of the method.
Direct Method for Resolution of Optimal Control Problem with Free Initial Condition
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Louadj Kahina
2012-01-01
Full Text Available The theory of control analyzes the proprieties of commanded systems. Problems of optimal control (OC have been intensively investigated in the world literature for over forty years. During this period, series of fundamental results have been obtained, among which should be noted the maximum principle (Pontryagin et al., 1962 and dynamic programming (Bellman, 1963. For many of the problems of the optimal control theory (OCT, adequate solutions are found (Bryson and Yu-chi, 1969, Lee and Markus, 1967, Gabasov and Kirillova, 1977, 1978, 1980. Results of the theory were taken up in various fields of science, engineering, and economics. The present paper aims at extending the constructive methods of Balashevich et al., (2000 that were developed for the problems of optimal control with the bounded initial state is not fixed are considered.
A novel hybrid optimization algorithm for diferential-algebraic control problems
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F. S. Lobato
2007-09-01
Full Text Available Dynamic optimization problems can be numerically solved by direct, indirect and Hamilton-Jacobi-Bellman methods. In this paper, the differential-algebraic approach is incorporated into a hybrid method, extending the concepts of structural and differential indexes, consistent initialization analysis, index reduction and dynamic degrees of freedom to the optimal control problem. The resultant differential-algebraic optimal control problem is solved in the following steps: transformation of the original problem into a standard nonlinear programming problem that provides control and state variables, switching time estimates and costate variables profiles with the DIRCOL code; definition of the switching function and the automatically generated sequence of index-1 differential-algebraic boundary value problems from Pontryagin’s minimum principle by using the developed Otima code; and finally, application of the COLDAE code with the results of the direct method as an initial guess. The proposed hybrid method is illustrated with a pressure-constrained batch reactor optimization problem associated with the slack variable method.
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Mariela Olguín
2015-01-01
Full Text Available The objective of this work is to make the numerical analysis, through the finite element method with Lagrange’s triangles of type 1, of a continuous optimal control problem governed by an elliptic variational inequality where the control variable is the internal energy g. The existence and uniqueness of this continuous optimal control problem and its associated state system were proved previously. In this paper, we discretize the elliptic variational inequality which defines the state system and the corresponding cost functional, and we prove that there exist a discrete optimal control and its associated discrete state system for each positive h (the parameter of the finite element method approximation. Finally, we show that the discrete optimal control and its associated state system converge to the continuous optimal control and its associated state system when the parameter h goes to zero.
Energy Technology Data Exchange (ETDEWEB)
Spoto, Marta Helena Fillet; Alcarde, Andre Ricardo; Gurgel, Maria Silvia do Amaral; Blumer, Lucimara; Walder, Julio Marcos Melges; Domarco, Rachel Elisabeth [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Irradiacao de Alimentos e Radioentomologia]. E-mail: aalcarde@cena.usp.br; Gallo, Claudio Rosa [Sao Paulo Univ., Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz
2000-09-01
This work evaluated the effect of gamma radiation on reducing the population of Staphylococcus aureus, Escherichia coli nd Salmonella typhimurium in ground chicken breast stored under refrigeration. The experiment included a control and 4 doses of gamma radiation ( 2.0, 4.0, 6.0 and 8.0 kGy) along with 5 periods of storage under refrigeration ( 1, 7 14, 21 and 28 days). Samples of ground chicken breast were inoculated with Staphylococcus aureus (ATCC 14458), Escherichia coli (ATCC 11105) and Salmonella typhimurium (ATCC 0626), irradiated at temperatures between 4 and 8 deg C and stored under refrigeration (5 deg C) for 28 days. The increased radiation dose and period of storage under refrigeration caused a reduction of Staphylococcus aureus, Escherichia coli and Salmonella typhimurium populations in the ground chicken breast. Mean radiation D values determined for Staphylococcus aureus and Escherichia coli were 0.41 and 0.72 kGy, respectively. Gamma irradiation was an effective treatment for chicken meat conservation because the radiation dose of 6.0 kGy kept the ground chicken breast within the microbiological limits established by the Brazilian legislation for up to 28 days under refrigeration. (author)
Chen, G.; Zheng, Q.; Coleman, M.; Weerakoon, S.
1983-01-01
This paper briefly reviews convergent finite difference schemes for hyperbolic initial boundary value problems and their applications to boundary control systems of hyperbolic type which arise in the modelling of vibrations. These difference schemes are combined with the primal and the dual approaches to compute the optimal control in the unconstrained case, as well as the case when the control is subject to inequality constraints. Some of the preliminary numerical results are also presented.
Growth and development of microseismics applied to ground control and mine safety
Energy Technology Data Exchange (ETDEWEB)
Leighton, F.
1983-08-01
The microseismic technique has advanced a great deal in recent years and has been used with moderate success in a number of different applications in the mining industry. More potential users are becoming aware of its capabilities and are making efforts to use the technology. As mining continues to greater depths and stability problems become more intense, use can only be expected to expand. Current Bureau research is aimed at better use, with particular regard to the reliability of data analysis procedures. Experience to date has shown that, while the techniques are beneficial and can contribute substantially to both mine safety and mine production, reliability problems exist, specifically in the areas of false warnings and of structural failures where warning is not provided. It seem, however, that these reliability problems can be resolved with continued research and development.
Vejdani, H R; Blum, Y; Daley, M A; Hurst, J W
2013-12-01
We proposed three swing leg control policies for spring-mass running robots, inspired by experimental data from our recent collaborative work on ground running birds. Previous investigations suggest that animals may prioritize injury avoidance and/or efficiency as their objective function during running rather than maintaining limit-cycle stability. Therefore, in this study we targeted structural capacity (maximum leg force to avoid damage) and efficiency as the main goals for our control policies, since these objective functions are crucial to reduce motor size and structure weight. Each proposed policy controls the leg angle as a function of time during flight phase such that its objective function during the subsequent stance phase is regulated. The three objective functions that are regulated in the control policies are (i) the leg peak force, (ii) the axial impulse, and (iii) the leg actuator work. It should be noted that each control policy regulates one single objective function. Surprisingly, all three swing leg control policies result in nearly identical subsequent stance phase dynamics. This implies that the implementation of any of the proposed control policies would satisfy both goals (damage avoidance and efficiency) at once. Furthermore, all three control policies require a surprisingly simple leg angle adjustment: leg retraction with constant angular acceleration.
A Real-Time Optimization Framework for the Iterative Controller Tuning Problem
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Gene A. Bunin
2013-09-01
Full Text Available We investigate the general iterative controller tuning (ICT problem, where the task is to find a set of controller parameters that optimize some user-defined performance metric when the same control task is to be carried out repeatedly. Following a repeatability assumption on the system, we show that the ICT problem may be formulated as a real-time optimization (RTO problem, thus allowing for the ICT problem to be solved in the RTO framework, which is both very flexible and comes with strong theoretical guarantees. In particular, we propose the use of a recently released RTO solver and outline a simple procedure for how this solver may be configured to solve ICT problems. The effectiveness of the proposed method is illustrated by successfully applying it to four case studies—two experimental and two simulated—that cover the tuning of model-predictive, general fixed-order and PID controllers, as well as a system of controllers working in parallel.
Miroshnichenko, I. P.; Parinov, I. A.
2017-06-01
It is proposed the computational-experimental ground of newly developed optical device for contactless measurement of small spatial displacements of control object surfaces based on the use of new methods of laser interferometry. The proposed device allows one to register linear and angular components of the small displacements of control object surfaces during the diagnosis of the condition of structural materials for forced elements of goods under exploring by using acoustic non-destructive testing methods. The described results are the most suitable for application in the process of high-precision measurements of small linear and angular displacements of control object surfaces during experimental research, the evaluation and diagnosis of the state of construction materials for forced elements of goods, the study of fast wave propagation in layered constructions of complex shape, manufactured of anisotropic composite materials, the study of damage processes in modern construction materials in mechanical engineering, shipbuilding, aviation, instrumentation, power engineering, etc.
Gill, C O; McGinnis, J C
1995-01-01
Rates of O(2) absorption from air were determined for a type of commercial O(2) scavenger that is formulated for rapid O(2) absorption at chiller temperatures. Rates of O(2) absorption from N(2) atmospheres containing 600 ppm O(2) were determined for trays that each contained 350 g of ground beef. Packs with controlled atmospheres of N(2) that contained ground beef and O(2) scavengers were prepared, to determine the conditions under which the scavengers could prevent the transient discolouration of the meat which arises from its reaction with the residual O(2) initially present in pack atmospheres. The rates of O(2) absorption by individual scavengers varied from the average by ±50%. The rate of O(2) absorption declined with decreasing oxygen concentration, from an average value per scavenger of about 12 ml h(-1) when O(2) concentrations were between 20 and 10%. At O(2) concentrations absorption was directly proportioned to the O(2) concentration so that the O(2) concentration in an atmosphere in a gas-impermeable pouch declined exponentially with time. The absorption of O(2) by ground beef was similarly dependent on the O(2) concentration. At 2 °C, the transient discolouration of beef in atmospheres initially containing about 50 ppm O(2) was prevented by the presence of 17.5 scavengers per l of atmosphere. At -15 °C, discolouration was prevented by 5 scavengers per l. The findings indicate that the O(2) concentration in pack atmospheres has to be reduced below 10 ppm within 30 min at 2 °C, or 2 h at -1.5 °C if ground beef is not to transiently discolour. It is unlikely that the required rates of O(2) absorption could be obtained economically with currently available, commercial O(2) scavengers.
Detecting Internal Control Problems Based on COSO and Islamic Perspective: Case on SMEs
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Yuniarti Hidayah Suyoso Putra
2014-03-01
Full Text Available Objective – The presence of Small Medium Enterprises (SMEs has been able to be livelihoods sources and absorb more labor, even though it has a relative smaller contribution of additional value compared to the Large-scale Enterprises. The number of economic actors of SMEs spread across area from urban to rural. However, SMEs have faced several serious problems. These problems are caused by the unique characteristics of SMEs itself. First, lack of managerial skills due to limited human resources and lack of monitoring which it is rarely conducted by the manager or the owner. Second, lack of information and technology to carry out operations. Both problems have great impacts in lack of internal controls. Third, SMEs also face problems in developing business scale, limited access to capital to the banks and financial institutions due to the lack of transparency. Therefore, this research aimed to detect to what extent of the problems arising in the application and assessment of internal controls performed by SMEs.Method – The research employs descriptive qualitative research method through direct observation, interview and business documentation owned by the company. Research materials are 29 SMEs consisting of 19 trading SMEs and 10 service SMEs. All SMEs are located in Malang city. Detection of application and assessment of internal controls in this study is based on the COSO framework and the Islamic perspective.Result – Internal control activities indicators apply the five principles of COSO framework which focused on three layers. First layer is self-assessment control area. Second layer is environment control area and the third layer is independent control area. While the Islamic perspective is focused on the internal control of business activities based on the Qur'an and Hadith. The results derive from application and assessment based on COSO framework and Islamic perspectives are complementary in improving the practice of internal
Spaceborne Autonomous and Ground Based Relative Orbit Control for the TerraSAR-X/TanDEM-X Formation
Ardaens, J. S.; D'Amico, S.; Kazeminejad, B.; Montenbruck, O.; Gill, E.
2007-01-01
. The goal of the ground segment is thus to regularly correct this configuration by performing small orbit correction maneuvers on TDX. The ground station contacts are limited due to the geographic position of the station and the costs for contact time. Only with a polar ground station a contact visibility is possible every orbit for LEO satellites. TSX and TDX use only the Weilheim ground station (in the southern part of Germany) during routine operations. This station allows two scheduled contact per day for the nominal orbit configuration, meaning that the satellite conditions can be checked with an interval of 12 hours. While this limitation is usually not critical for single satellite operations, the visibility constraints drive the achievable orbit control accuracy for a LEO formation if a ground based approach is chosen. Along-track position uncertainties and maneuver execution errors affect the relative motion and can be compensated only after a ground station contact.
Park, Chandeok
This dissertation presents a general methodology for solving the optimal feedback control problem in the context of Hamiltonian system theory. It is first formulated as a two point boundary value problem for a standard Hamiltonian system, and the associated phase flow is viewed as a canonical transformation. Then relying on the Hamilton-Jacobi theory, we employ generating functions to develop a unified methodology for solving a variety of optimal feedback control formulations with general types of boundary conditions. The major accomplishment is to establish a theoretical connection between the optimal cost function and a special kind of generating function. Guided by this recognition, we are ultimately led to a new flexible representation of the optimal feedback control law for a given system, which is adjustable to various types of boundary conditions by algebraic conversions and partial differentiations. This adaptive property provides a substantial advantage over the classical dynamic programming method in the sense that we do not need to solve the Hamilton-Jacobi-Bellman equation repetitively for varying types of boundary conditions. Furthermore for a special type of boundary condition, it also enables us to work around an inherent singularity of the Hamilton-Jacobi-Bellman equation by a special algebraic transformation. Taking full advantage of these theoretical insights, we develop a systematic algorithm for solving a class of optimal feedback control problems represented by smooth analytic Hamiltonians, and apply it to problems with different characteristics. Then, broadening the practical utility of generating functions for problems where the relevant Hamiltonian is non-smooth, we construct a pair of Cauchy problems from the associated Hamilton-Jacobi equations. This alternative formulation is justified by solving problems with control constraints which usually feature non-smoothness in the control logic. The main result of this research establishes that
A randomized controlled trial of an intervention for infants’ behavioral sleep problems
Hall, Wendy A.; Hutton, Eileen; Brant, Rollin F.; Collet, Jean Paul; Gregg, Kathy; Saunders, Roy; Ipsiroglu, Osman; Gafni, Amiram; Triolet, Kathy; Tse, Lillian; Bhagat, Radhika; Wooldridge, Joanne
2015-01-01
Background Infant behavioral sleep problems are common, with potential negative consequences. We conducted a randomized controlled trial to assess effects of a sleep intervention comprising a two-hour group teaching session and four support calls over 2 weeks. Our primary outcomes were reduced numbers of nightly wakes or parent report of sleep problem severity. Secondary outcomes included improvement in parental depression, fatigue, sleep, and parent cognitions about infant sleep. Methods Two...
Tang, Yuelong; Hua, Yuchun
2017-01-01
In this paper, a semidiscrete finite element method for solving bilinear parabolic optimal control problems is considered. Firstly, we present a finite element approximation of the model problem. Secondly, we bring in some important intermediate variables and their error estimates. Thirdly, we derive a priori error estimates of the approximation scheme. Finally, we obtain the superconvergence between the semidiscrete finite element solutions and projections of the exact solutions. A numerical example is presented to verify our theoretical results.
Farzanehpour, M.; Tokatly, I. V.
2016-05-01
We use analytic (current) density-potential maps of time-dependent (current) density-functional theory [TD(C)DFT] to inverse engineer analytically solvable time-dependent quantum problems. In this approach the driving potential (the control signal) and the corresponding solution of the Schrödinger equation are parametrized analytically in terms of the basic TD(C)DFT observables. We describe the general reconstruction strategy and illustrate it with a number of explicit examples. First we consider the real space one-particle dynamics driven by a time-dependent electromagnetic field and recover, from the general TDDFT reconstruction formulas, the known exact solution for a driven oscillator with a time-dependent frequency. Then we use analytic maps of the lattice TD(C)DFT to control quantum dynamics in a discrete space. As a first example we construct a time-dependent potential which generates prescribed dynamics on a tight-binding chain. Then our method is applied to the dynamics of spin-1/2 driven by a time-dependent magnetic field. We design an analytic control pulse that transfers the system from the ground to excited state and vice versa. This pulse generates the spin flip thus operating as a quantum not gate.
Gender Differences in Interpersonal Problems of Alcohol-Dependent Patients and Healthy Controls
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Marc Walter
2009-12-01
Full Text Available Alcohol dependence is a heavy burden on patients, their families, and society. Epidemiological studies indicate that alcohol dependence will affect many individuals at some time in their lives, with men affected more frequently than women. Since alcohol-dependent patients often exhibit a lack of social skills and suffer from interpersonal problems, the aim of this study is to elucidate whether men and women experience the same interpersonal problems. Eighty-five alcohol-dependent patients (48 men; 37 women after detoxification and 62 healthy controls (35 men; 27 women were recruited. Interpersonal problems were measured with the Inventory of Interpersonal Problems (IIP-64. Additionally, alcohol-dependent patients were interviewed with the Alcohol Use Disorders Identification Test (AUDIT and were subtyped according to Lesch’s Alcohol Typology (LAT. There were no significant gender differences in the AUDIT and LAT between alcohol-dependent men and women. Interpersonal problems of alcohol-dependent men differed significantly in one out of eight dimensions from controls; alcohol-dependent men perceive themselves as colder than male controls. Alcohol-dependent women differed in four out of eight interpersonal dimensions from female controls. Alcohol-dependent women rated themselves as significantly more vindictive, more introverted, more overly accommodating and more intrusive than female controls. Results suggest that alcohol-dependent men and women suffer from different interpersonal problems and furthermore alcohol-dependent women perceive more interpersonal problems, whereas the severity of alcohol dependence did not differ between the groups. Our findings indicate that alcohol-dependent women may profit more from a gender-specific treatment approach aimed at improving treatment outcome than alcohol-dependent men.
A non-standard optimal control problem arising in an economics application
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Alan Zinober
2013-04-01
Full Text Available A recent optimal control problem in the area of economics has mathematical properties that do not fall into the standard optimal control problem formulation. In our problem the state value at the final time the state, y(T = z, is free and unknown, and additionally the Lagrangian integrand in the functional is a piecewise constant function of the unknown value y(T. This is not a standard optimal control problem and cannot be solved using Pontryagin's Minimum Principle with the standard boundary conditions at the final time. In the standard problem a free final state y(T yields a necessary boundary condition p(T = 0, where p(t is the costate. Because the integrand is a function of y(T, the new necessary condition is that y(T should be equal to a certain integral that is a continuous function of y(T. We introduce a continuous approximation of the piecewise constant integrand function by using a hyperbolic tangent approach and solve an example using a C++ shooting algorithm with Newton iteration for solving the Two Point Boundary Value Problem (TPBVP. The minimising free value y(T is calculated in an outer loop iteration using the Golden Section or Brent algorithm. Comparative nonlinear programming (NP discrete-time results are also presented.
Childhood Reports of Food Neglect and Impulse Control Problems and Violence in Adulthood
Vaughn, Michael G.; Salas-Wright, Christopher P.; Naeger, Sandra; Huang, Jin; Piquero, Alex R.
2016-01-01
Food insecurity and hunger during childhood are associated with an array of developmental problems in multiple domains, including impulse control problems and violence. Unfortunately, extant research is based primarily on small convenience samples and an epidemiological assessment of the hunger-violence link is lacking. The current study employed data from Wave 1 (2001–2002) and Wave 2 (2004–2005) of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). The NESARC is a nationally representative sample of non-institutionalized U.S. residents aged 18 years and older. Participants who experienced frequent hunger during childhood had significantly greater impulsivity, worse self-control, and greater involvement in several forms of interpersonal violence. These effects were stronger among whites, Hispanics, and males. The findings support general theoretical models implicating impulse control problems as a key correlate of crime and violence and add another facet to the importance of ameliorating food neglect in the United States. PMID:27043598
Childhood Reports of Food Neglect and Impulse Control Problems and Violence in Adulthood.
Vaughn, Michael G; Salas-Wright, Christopher P; Naeger, Sandra; Huang, Jin; Piquero, Alex R
2016-03-30
Food insecurity and hunger during childhood are associated with an array of developmental problems in multiple domains, including impulse control problems and violence. Unfortunately, extant research is based primarily on small convenience samples and an epidemiological assessment of the hunger-violence link is lacking. The current study employed data from Wave 1 (2001-2002) and Wave 2 (2004-2005) of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). The NESARC is a nationally representative sample of non-institutionalized U.S. residents aged 18 years and older. Participants who experienced frequent hunger during childhood had significantly greater impulsivity, worse self-control, and greater involvement in several forms of interpersonal violence. These effects were stronger among whites, Hispanics, and males. The findings support general theoretical models implicating impulse control problems as a key correlate of crime and violence and add another facet to the importance of ameliorating food neglect in the United States.
Directory of Open Access Journals (Sweden)
Marcantonio M. Spada
2015-06-01
Full Text Available The present study explored the relationship between metacognitions, attentional control, and the severity of gambling in problem gamblers. One hundred and twenty six problem gamblers completed the Depression Anxiety Stress Scales 21, the Meta-Cognitions Questionnaire 30, the Attentional Control Scale, and the Problem Gambling Severity Index. Results revealed that negative affect, four out of five metacognitions factors (positive beliefs about worry, negative beliefs about thoughts concerning danger and uncontrollability, cognitive confidence and beliefs about the need to control thoughts, and all attentional control factors (focusing, shifting and flexible control of thought were correlated, in the predicted directions, with the severity of gambling. The same metacognitions were also found to be correlated, in the predicted directions, with attention focusing, however only negative beliefs about thoughts concerning danger and uncontrollability and cognitive confidence were found to be correlated with attention shifting and flexible control of thought. A hierarchical regression analysis showed that beliefs about the need to control thoughts were the only predictor of the severity of gambling controlling for negative affect. Overall these findings support the hypotheses and are consistent with the metacognitive model of psychological dysfunction. The implications of these findings are discussed.
Quadratic partial eigenvalue assignment problem with time delay for active vibration control
Pratt, J. M.; Singh, K. V.; Datta, B. N.
2009-08-01
Partial pole assignment in active vibration control refers to reassigning a small set of unwanted eigenvalues of the quadratic eigenvalue problem (QEP) associated with the second order system of a vibrating structure, by using feedback control force, to suitably chosen location without altering the remaining large number of eigenvalues and eigenvectors. There are several challenges of solving this quadratic partial eigenvalue assignment problem (QPEVAP) in a computational setting which the traditional pole-placement problems for first-order control systems do not have to deal with. In order to these challenges, there has been some work in recent years to solve QPEVAP in a computationally viable way. However, these works do not take into account of the practical phenomenon of the time-delay effect in the system. In this paper, a new "direct and partial modal" approach of the quadratic partial eigenvalue assignment problem with time-delay is proposed. The approach works directly in the quadratic system without requiring transformation to a standard state-space system and requires the knowledge of only a small number of eigenvalues and eigenvectors that can be computed or measured in practice. Two illustrative examples are presented in the context of active vibration control with constant time-delay to illustrate the success of our proposed approach. Future work includes generalization of this approach to a more practical complex time-delay system and extension of this work to the multi-input problem.
Application of PID controller to 2D differential geometric guidance problem
Institute of Scientific and Technical Information of China (English)
Chaoyong LI; Wuxing JING
2007-01-01
This paper presents the application of the proportional-integral-derivative (PID) controller to the flight control system (FCS) for two-dimensional (2D) differential geometric (DG) guidance and control problem. In particular,the performance of the designed FCS is investigated. To this end, the commanded angle-of-attack is firstly developed in the time domain using the classical DG formulations. Then, the classical PID controller is introduced to develop a FCS so as to form the 2D DG guidance and control system, and the PID controller parameters are determined by the Ziegler-Nichols method as well as the Routh-Hurwitz stability algorithm to guarantee the convergence of the system error. The results demonstrate that the designed controller yields a fast responding system, and the resulting DG guidance and control system is viable and effective in a realistic missile defense engagement.
2015-04-24
Allgwer and A. Zheng, Nonlinear model predictive control vol. 26: Springer , 2000. [10] J. M. Park, D. W. Kim, Y. S. Yoon, H. J. Kim, and K. S. Yi...include modeling, simulation, and control of dynamic systems, with applications to energy systems, multibody dynamics, vehicle systems, and biomechanics
Demonstrations of LSS active vibration control technology on representative ground-based testbeds
Hyland, David C.; Phillips, Douglas J.; Collins, Emmanuel G., Jr.
1991-01-01
This paper describes two experiments which successfully demonstrate control of flexible structures. The first experiment involved control design and implementation for the ACES structure at NASA Marshall Space Flight Center, while the second experiment was conducted using the Multi-Hex Prototype structure. The paper concludes with some remarks on the lessons learned from conducting these experiments.
Tang, Xiaojun
2016-04-01
The main purpose of this work is to provide multiple-interval integral Gegenbauer pseudospectral methods for solving optimal control problems. The latest developed single-interval integral Gauss/(flipped Radau) pseudospectral methods can be viewed as special cases of the proposed methods. We present an exact and efficient approach to compute the mesh pseudospectral integration matrices for the Gegenbauer-Gauss and flipped Gegenbauer-Gauss-Radau points. Numerical results on benchmark optimal control problems confirm the ability of the proposed methods to obtain highly accurate solutions.
Institute of Scientific and Technical Information of China (English)
Wei Gong; Ningning Yan
2009-01-01
In this paper.we discuss the a posteriori error estimate of the finite element approximation for the boundary control problems governed by the parabolic partial differential equations.Three different a posteriori error estimators are provided for the parabolic boundary control problems with the observations of the distributed state.the boundary state and the final state.It is proven that these estimators are reliable bounds of the finite element approximation errors,which can be used as the indicators of the mesh refinement in adaptive finite element methods.
H2 control of a one-quarter semi-active ground vehicle suspension
Directory of Open Access Journals (Sweden)
L.C. Félix-Herrán
2016-06-01
Full Text Available Magneto-rheological (MR dampers are effective solutions in improving vehicle stability and passenger comfort. However, handling these dampers implies a strong effort in modeling and control. This research proposes an H2 controller, based on a Takagi–Sugeno (T–S fuzzy model, for a two-degrees-of-freedom (2-DOF one-quarter vehicle semi-active suspension with an MR damper; a system with important applications in automotive industry. Regarding performance criteria (in frequency domain handled herein, the developed controller considerably improves the passive suspension's efficiency. Moreover, nonlinear actuator dynamics usually avoided in reported work, is included in controller's synthesis; improving the relevance of research outcomes because the controller is synthesized from a closer-to-reality suspension model. Going further, outcomes of this research are compared (based on frequency domain performance criteria and a common time domain test with reported work to highlight the outstanding results. H2 controller is given in terms of quadratic Lyapunov stability theory and carried out by means of Linear Matrix Inequalities (LMI, and the command signal is applied via the Parallel Distributed Compensation (PDC approach. A case of study, with real data, is developed and simulation work supports the results. The methodology applied herein can be extended to include other vehicle suspension's dynamics towards a general chassis control.
Directory of Open Access Journals (Sweden)
Qinghua Zeng
2015-07-01
Full Text Available This article proposes a linear matrix inequality–based robust controller design approach to implement the synchronous design of aircraft control discipline and other disciplines, in which the variation in design parameters is treated as equivalent perturbations. Considering the complicated mapping relationships between the coefficient arrays of aircraft motion model and the aircraft design parameters, the robust controller designed is directly based on the variation in these coefficient arrays so conservative that the multidisciplinary design optimization problem would be too difficult to solve, or even if there is a solution, the robustness of design result is generally poor. Therefore, this article derives the uncertainty model of disciplinary design parameters based on response surface approximation, converts the design problem of the robust controller into a problem of solving a standard linear matrix inequality, and theoretically gives a less conservative design method of the robust controller which is based on the variation in design parameters. Furthermore, the concurrent subspace approach is applied to the multidisciplinary system with this kind of robust controller in the design loop. A multidisciplinary design optimization of a tailless aircraft as example is shown that control discipline can be synchronous optimal design with other discipline, especially this method will greatly reduce the calculated amount of multidisciplinary design optimization and make multidisciplinary design optimization results more robustness of flight performance.
Use of COTS in the Multimission Advanced Ground Intelligent Control (MAGIC) program
Energy Technology Data Exchange (ETDEWEB)
Crowley, N.L.
1997-11-01
This tutorial will discuss the experiences of the Space System Technologies Division of the USAF Phillips Laboratory (PL/VTS) in developing a COTS-based satellite control system. The system`s primary use is a testbed for new technologies that are intended for future integration into the operational satellite control system. As such, the control system architecture must be extremely open and flexible so we can integrate new components and functions easily and also provide our system to contractors for their component work. The system is based on commercial hardware, is based on Windows NT, and makes the maximum use of COTS components and industry standards.
Constrained regulator problem for linear uncertain systems: control of a pH process
Directory of Open Access Journals (Sweden)
2006-01-01
Full Text Available The regulator problem for linear uncertain continuous-time systems having control constraints is considered. Necessary and sufficient conditions of positive invariance of polyhedral domains are extended to the case of continuous-time uncertain systems. Robust constrained regulators are then derived. An application to the control of pH in a stirred tank is then presented. First, the uncertainty in the pH process is evaluated from first-principle models, then the design of a robust constrained regulator is presented. Simulation results show that this control law is easy to implement and that robust asymptotic stability and control admissibility are guaranteed.
Institute of Scientific and Technical Information of China (English)
Yanzhen Chang; Danping Yang
2008-01-01
In this paper, we consider the finite element approximation of the distributed optimal control problems of the stationary Bénard type under the pointwise control constraint. The states and the co-states are approximated by polynomial functions of lowest-order mixed finite element space or piecewise linear functions and the control is approximated by piecewise constant functions. We give the superconvergence analysis for the control; it is proved that the approximation has a second-order rate of convergence. We further give the superconvergence analysis for the states and the co-states. Then we derive error estimates in L∞-norm and optimal error estimates in L2-norm.
The role of unattended ground sensors (UGS) in regional confidence building and arms control
Energy Technology Data Exchange (ETDEWEB)
Vannoni, M.; Duggan, R.
1997-03-01
Although the Cold War has ended, the world has not become more peaceful. Without the stability provided by an international system dominated by two super-powers, local conflicts are more likely to escalate. Agreements to counter destabilizing pressures in regional conflicts can benefit from the use of cooperative monitoring. Cooperative monitoring is the collecting, analyzing, and sharing of information among parties to an agreement. Ground sensor technologies can contribute to the collection of relevant information. If implemented with consideration for local conditions, cooperative monitoring can build confidence, strengthen existing agreements, and set the stage for continued progress. This presentation describes two examples: the Israeli-Egyptian Sinai agreements of the 1970s and a conceptual example for the contemporary Korean Peninsula. The Sinai was a precedent for the successful use of UGS within the context of cooperative monitoring. The Korean Peninsula is the world`s largest military confrontation. Future confidence building measures that address the security needs of both countries could decrease the danger of conflict and help create an environment for a peace agreement.
Deformation Monitoring of Waste-Rock-Backfilled Mining Gob for Ground Control
Zhao, Tongbin; Zhang, Yubao; Zhang, Zhenyu; Li, Zhanhai; Ma, Shuqi
2017-01-01
Backfill mining is an effective option to mitigate ground subsidence, especially for mining under surface infrastructure, such as buildings, dams, rivers and railways. To evaluate its performance, continual long-term field monitoring of the deformation of backfilled gob is important to satisfy strict public scrutiny. Based on industrial Ethernet, a real-time monitoring system was established to monitor the deformation of waste-rock-backfilled gob at −700 m depth in the Tangshan coal mine, Hebei Province, China. The designed deformation sensors, based on a resistance transducer mechanism, were placed vertically between the roof and floor. Stress sensors were installed above square steel plates that were anchored to the floor strata. Meanwhile, data cables were protected by steel tubes in case of damage. The developed system continually harvested field data for three months. The results show that industrial Ethernet technology can be reliably used for long-term data transmission in complicated underground mining conditions. The monitoring reveals that the roof subsidence of the backfilled gob area can be categorized into four phases. The bearing load of the backfill developed gradually and simultaneously with the deformation of the roof strata, and started to be almost invariable when the mining face passed 97 m. PMID:28475168
Deformation Monitoring of Waste-Rock-Backfilled Mining Gob for Ground Control.
Zhao, Tongbin; Zhang, Yubao; Zhang, Zhenyu; Li, Zhanhai; Ma, Shuqi
2017-05-05
Backfill mining is an effective option to mitigate ground subsidence, especially for mining under surface infrastructure, such as buildings, dams, rivers and railways. To evaluate its performance, continual long-term field monitoring of the deformation of backfilled gob is important to satisfy strict public scrutiny. Based on industrial Ethernet, a real-time monitoring system was established to monitor the deformation of waste-rock-backfilled gob at -700 m depth in the Tangshan coal mine, Hebei Province, China. The designed deformation sensors, based on a resistance transducer mechanism, were placed vertically between the roof and floor. Stress sensors were installed above square steel plates that were anchored to the floor strata. Meanwhile, data cables were protected by steel tubes in case of damage. The developed system continually harvested field data for three months. The results show that industrial Ethernet technology can be reliably used for long-term data transmission in complicated underground mining conditions. The monitoring reveals that the roof subsidence of the backfilled gob area can be categorized into four phases. The bearing load of the backfill developed gradually and simultaneously with the deformation of the roof strata, and started to be almost invariable when the mining face passed 97 m.
Theoretical grounds of internal audit in the system of state financial control in Ukraine
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Dikan Larysa V.
2013-03-01
Full Text Available The article considers modern directions of reformation of the system of state financial control connected with introduction of the state internal financial control. It considers economic essence of the state internal financial control in the context of its components. It justifies the place of the internal audit in the system of the state internal financial control in Ukraine. It considers existing definitions of internal audit in legislative acts. It generalises views of scientists on interpretation of the “internal audit” notion. It provides definitions united in approaches. It conducts a critical analysis of generalised approaches. It offers the authors’ view on the essence of internal audit in budget institutions, which has certain positive features compared to existing ones.
Liu, Derong; Li, Hongliang; Wang, Ding
2015-06-01
In this paper, we establish error bounds of adaptive dynamic programming algorithms for solving undiscounted infinite-horizon optimal control problems of discrete-time deterministic nonlinear systems. We consider approximation errors in the update equations of both value function and control policy. We utilize a new assumption instead of the contraction assumption in discounted optimal control problems. We establish the error bounds for approximate value iteration based on a new error condition. Furthermore, we also establish the error bounds for approximate policy iteration and approximate optimistic policy iteration algorithms. It is shown that the iterative approximate value function can converge to a finite neighborhood of the optimal value function under some conditions. To implement the developed algorithms, critic and action neural networks are used to approximate the value function and control policy, respectively. Finally, a simulation example is given to demonstrate the effectiveness of the developed algorithms.
Liveness Problem of Petri Nets Supervisory Control Theory for Discrete Event Systems
Institute of Scientific and Technical Information of China (English)
Hong-Ye SU; Wei-Min WU; Jian CHU
2005-01-01
A quite great progress of the supervisory control theory for discrete event systems (DES)has been made in the past nearly twenty years, and now, automata, formal language and Petri nets become the main research tools. This paper focus on the Petri nets based supervisory control theory of DES. Firstly, we review the research results in this field, and claim that there generally exists a problem in Petri nets based supervisory control theory of DES, that is, the deadlock caused by the controller introduced to enforce the given specification occurs in the closed-loop systems, especially the deadlock occurs in the closed-loop system in which the original plant is live. Finally, a possible research direction is presented for the solution of this problem.
Institute of Scientific and Technical Information of China (English)
Danping Yang; Yanzhen Chang; Wenbin Liu
2008-01-01
In this paper,we investigate a priori error estimates and superconvergence properties for a model optimal control problem of bilinear type,which includes some parameter estimation application.The state and co-state are discretized by piecewise linear functions and control is approximated by piecewise constant functions.We derive a priori error estimates and superconvergence analysis for both the control and the state approximations.We also give the optimal L2-norm error estimates and the almost optimal L8-norm estimates about the state and co-state.The results can be readily used for constructing a posteriori error estimators in adaptive finite element approximation of such optimal control problems.
Study on the Nonsingular Problem of Fractional-Order Terminal Sliding Mode Control
Directory of Open Access Journals (Sweden)
Kening Li
2013-01-01
Full Text Available An improved type of control strategy combining the fractional calculus with nonsingular terminal sliding mode control named non-singular fractional terminal sliding mode control (NFOTSM is proposed for the nonlinear tire-road friction control system of vehicle in this paper. A fractional-order switching manifold is proposed, and the corresponding control law is formulated based on the Lyapunov stability theory to guarantee the sliding condition. The proposed controller ensures the finite time stability of the closed-loop system. Then, a terminal attractor is introduced to solve the singularity problem of fractional terminal sliding mode control (FOTSM. Finally, the performance of the NFOTSM is fully investigated compared with other related algorithms to find the effectiveness for the tire-road friction system. The results show that the NFOTSM has better performance than other related algorithms.
Directory of Open Access Journals (Sweden)
Caixian Sun
2014-01-01
Full Text Available This paper is devoted to the average consensus problems in directed networks of agents with unknown control direction. In this paper, by using Nussbaum function techniques and Laplacian matrix, novel average consensus protocols are designed for multiagent systems with unknown control direction in the cases of directed networks with fixed and switching topology. In the case of switching topology, the disagreement vector is utilized. Finally, simulation is provided to demonstrate the effectiveness of our results.
On the hierarchical risk-averse control problems for diffusion processes
Befekadu, Getachew K.; Veremyev, Alexander; Pasiliao, Eduardo L.
2016-01-01
In this paper, we consider a risk-averse control problem for diffusion processes, in which there is a partition of the admissible control strategy into two decision-making groups (namely, the {\\it leader} and {\\it follower}) with different cost functionals and risk-averse satisfactions. Our approach, based on a hierarchical optimization framework, requires that a certain level of risk-averse satisfaction be achieved for the {\\it leader} as a priority over that of the {\\it follower's} risk-ave...
Institute of Scientific and Technical Information of China (English)
Ningning YAN; Zhaojie ZHOU
2008-01-01
In this paper,we study a posteriori error estimates of the edge stabilization Galerkin method for the constrained optimal control problem governed by convection-dominated diffusion equations.The residual-type a posteriori error estimators yield both upper and lower bounds for control u measured in L2-norm and for state y and costate p measured in energy norm.Two numerical examples are presented to illustrate the effectiveness of the error estimators provided in this paper.
LONG-TERM STABILITY OF THE LOCAL GROUND CONTROL NETWORK AT THE CO-LOCATION SITE OF MEDICINA
Abbondanza, C.; Sarti, P.; Legrand, J.
2009-12-01
ITRF combinations rely on the availability of accurate tie vectors linking reference points of space geodetic techniques. Co-located instruments are assumed to move consistently and no local relative motion is taken into account. Instabilities may degrade the quality of the co-location itself and perturb the result of ITRF combinations. This work aims to determine the stability of the local ground control network at Medicina (Italy) with independent surveying methods. The observatory hosts a co-location between a VLBI telescope and two GPS antennas, MEDI and MSEL. It is located in the Po Plain where thick layers of clays are the prevalent soil characteristics. Hence, provision of long term stability of geodetic monuments is a challenge and monitoring their stability is an issue. MEDI and the VLBI station regularly contribute to the determination of ITRF, while MSEL is part of the EUREF network. A set of five tie vectors observations linking the VLBI and MEDI reference points was acquired between 2001 and 2007. It is our main tool for performing local deformation analysis. Additionally, the GPS time series of MEDI and MSEL were used to cross check and confirm the local instability detected by terrestrial methods. To achieve a rigorous and reliable investigation of the local stability, multi-epoch terrestrial observations were homogeneously processed according to common parameterizations in a consistent reference frame. Similarly, continuous GPS observations from MEDI and MSEL were analysed according to the new EPN reprocessing strategy in order to monitor the short baseline between MEDI and MSEL; to spotlight any change in its length. Both approaches confirm differential motions at the site which can be related to monument instabilities originated by the particularly unfavourable local geological setting and the inapt design of the monuments foundation. The monuments move non homogeneously at rates reaching up to 1.6 mm/year, this value being comparable to intra
Solution of Constrained Optimal Control Problems Using Multiple Shooting and ESDIRK Methods
DEFF Research Database (Denmark)
Capolei, Andrea; Jørgensen, John Bagterp
2012-01-01
In this paper, we describe a novel numerical algorithm for solution of constrained optimal control problems of the Bolza type for stiff and/or unstable systems. The numerical algorithm combines explicit singly diagonally implicit Runge-Kutta (ESDIRK) integration methods with a multiple shooting...... algorithm. As we consider stiff systems, implicit solvers with sensitivity computation capabilities for initial value problems must be used in the multiple shooting algorithm. Traditionally, multi-step methods based on the BDF algorithm have been used for such problems. The main novel contribution...... of this paper is the use of ESDIRK integration methods for solution of the initial value problems and the corresponding sensitivity equations arising in the multiple shooting algorithm. Compared to BDF-methods, ESDIRK-methods are advantageous in multiple shooting algorithms in which restarts and frequent...
Walking on smooth or rough ground: passive control of pretarsal attachment in ants.
Endlein, Thomas; Federle, Walter
2008-01-01
The hymenopteran tarsus is equipped with claws and a movable adhesive pad (arolium). Even though both organs are specialised for substrates of different roughness, they are moved by the same muscle, the claw flexor. Here we show that despite this seemingly unfavourable design, the use of arolium and claws can be adjusted according to surface roughness by mechanical control. Tendon pull experiments in ants (Oecophylla smaragdina) revealed that the claw flexor elicits rotary movements around several (pre-) tarsal joints. However, maximum angular change of claws, arolium and fifth tarsomere occurred at different pulling amplitudes, with arolium extension always being the last movement. This effect indicates that arolium use is regulated non-neuronally. Arolium unfolding can be suppressed on rough surfaces, when claw tips interlock and inhibit further contraction of the claw flexor or prevent legs from sliding towards the body. To test whether this hypothesised passive control operates in walking ants, we manipulated ants by clipping claw tips. Consistent with the proposed control mechanism, claw pruning resulted in stronger arolium extension on rough but not on smooth substrates. The control of attachment by the insect claw flexor system demonstrates how mechanical systems in the body periphery can simplify centralised, neuro-muscular feedback control.
Migration strategies for service-enabling ground control stations for unmanned systems
Kroculick, Joseph B.
2011-06-01
Future unmanned systems will be integrated into the Global Information Grid (GIG) and support net-centric data sharing, where information in a domain is exposed to a wide variety of GIG stakeholders that can make use of the information provided. Adopting a Service-Oriented Architecture (SOA) approach to package reusable UAV control station functionality into common control services provides a number of benefits including enabling dynamic plug and play of components depending on changing mission requirements, supporting information sharing to the enterprise, and integrating information from authoritative sources such as mission planners with the UAV control stations data model. It also allows the wider enterprise community to use the services provided by unmanned systems and improve data quality to support more effective decision-making. We explore current challenges in migrating UAV control systems that manage multiple types of vehicles to a Service-Oriented Architecture (SOA). Service-oriented analysis involves reviewing legacy systems and determining which components can be made into a service. Existing UAV control stations provide audio/visual, navigation, and vehicle health and status information that are useful to C4I systems. However, many were designed to be closed systems with proprietary software and hardware implementations, message formats, and specific mission requirements. An architecture analysis can be performed that reviews legacy systems and determines which components can be made into a service. A phased SOA adoption approach can then be developed that improves system interoperability.
OPTIMAL THICKNESS OF A CYLINDRICAL SHELL - AN OPTIMAL CONTROL PROBLEM IN LINEAR ELASTICITY THEORY
Directory of Open Access Journals (Sweden)
Peter Nestler
2013-01-01
Full Text Available In this paper we discuss optimization problems for cylindrical tubeswhich are loaded by an applied force. This is a problem of optimal control in linear elasticity theory (shape optimization. We are looking for an optimal thickness minimizing the deflection (deformation of the tube under the influence of an external force. From basic equations of mechanics, we derive the equation of deformation. We apply the displacement approach from shell theory and make use of the hypotheses of Mindlin and Reissner. A corresponding optimal control problem is formulated and first order necessary conditions for the optimal solution (optimal thickness are derived. We present numerical examples which were solved by the finite element method.
Li, Yanning
2013-10-01
This article presents a new robust control framework for transportation problems in which the state is modeled by a first order scalar conservation law. Using an equivalent formulation based on a Hamilton-Jacobi equation, we pose the problem of controlling the state of the system on a network link, using boundary flow control, as a Linear Program. Unlike many previously investigated transportation control schemes, this method yields a globally optimal solution and is capable of handling shocks (i.e. discontinuities in the state of the system). We also demonstrate that the same framework can handle robust control problems, in which the uncontrollable components of the initial and boundary conditions are encoded in intervals on the right hand side of inequalities in the linear program. The lower bound of the interval which defines the smallest feasible solution set is used to solve the robust LP (or MILP if the objective function depends on boolean variables). Since this framework leverages the intrinsic properties of the Hamilton-Jacobi equation used to model the state of the system, it is extremely fast. Several examples are given to demonstrate the performance of the robust control solution and the trade-off between the robustness and the optimality. © 2013 IEEE.
Evolutionary path control strategy for solving many-objective optimization problem.
Roy, Proteek Chandan; Islam, Md Monirul; Murase, Kazuyuki; Yao, Xin
2015-04-01
The number of objectives in many-objective optimization problems (MaOPs) is typically high and evolutionary algorithms face severe difficulties in solving such problems. In this paper, we propose a new scalable evolutionary algorithm, called evolutionary path control strategy (EPCS), for solving MaOPs. The central component of our algorithm is the use of a reference vector that helps simultaneously minimizing all the objectives of an MaOP. In doing so, EPCS employs a new fitness assignment strategy for survival selection. This strategy consists of two procedures and our algorithm applies them sequentially. It encourages a population of solutions to follow a certain path reaching toward the Pareto optimal front. The essence of our strategy is that it reduces the number of nondominated solutions to increase selection pressure in evolution. Furthermore, unlike previous work, EPCS is able to apply the classical Pareto-dominance relation with the new fitness assignment strategy. Our algorithm has been tested extensively on several scalable test problems, namely five DTLZ problems with 5 to 40 objectives and six WFG problems with 2 to 13 objectives. Furthermore, the algorithm has been tested on six CEC09 problems having 2 or 3 objectives. The experimental results show that EPCS is capable of finding better solutions compared to other existing algorithms for problems with an increasing number of objectives.
ε-MAXIMUM PRINCIPLE IN LINEAR PROBLEM OF HYBRID SYSTEM OPTIMUM CONTROL
Directory of Open Access Journals (Sweden)
O. R. Gabasova
2009-01-01
Full Text Available The paper reveals necessary and sufficient conditions of optimality and sub-optimality of the programs for a hybrid system in the class of discrete control actions. The conditions are formulated in the support terms of the initial problem.
Solvability for a Class of Abstract Two-Point Boundary Value Problems Derived from Optimal Control
Directory of Open Access Journals (Sweden)
Wang Lianwen
2007-01-01
Full Text Available The solvability for a class of abstract two-point boundary value problems derived from optimal control is discussed. By homotopy technique existence and uniqueness results are established under some monotonic conditions. Several examples are given to illustrate the application of the obtained results.
Solvability for a Class of Abstract Two-Point Boundary Value Problems Derived from Optimal Control
Directory of Open Access Journals (Sweden)
Lianwen Wang
2008-01-01
Full Text Available The solvability for a class of abstract two-point boundary value problems derived from optimal control is discussed. By homotopy technique existence and uniqueness results are established under some monotonic conditions. Several examples are given to illustrate the application of the obtained results.
Controlling Barium Sulphate Scale Deposition Problems in an unbleached Kraft Paper Mill
CSIR Research Space (South Africa)
Sithole, Bruce
2015-06-01
Full Text Available /phosphonates and polyacrylates were effective in reducing and controlling the scale deposit problems. Institution of these measures led to a cleaner paper machine that required far fewer boil outs than before. In addition, productivity improved and the fisheye defects...
On large-scale nonlinear programming techniques for solving optimal control problems
Energy Technology Data Exchange (ETDEWEB)
Faco, J.L.D.
1994-12-31
The formulation of decision problems by Optimal Control Theory allows the consideration of their dynamic structure and parameters estimation. This paper deals with techniques for choosing directions in the iterative solution of discrete-time optimal control problems. A unified formulation incorporates nonlinear performance criteria and dynamic equations, time delays, bounded state and control variables, free planning horizon and variable initial state vector. In general they are characterized by a large number of variables, mostly when arising from discretization of continuous-time optimal control or calculus of variations problems. In a GRG context the staircase structure of the jacobian matrix of the dynamic equations is exploited in the choice of basic and super basic variables and when changes of basis occur along the process. The search directions of the bound constrained nonlinear programming problem in the reduced space of the super basic variables are computed by large-scale NLP techniques. A modified Polak-Ribiere conjugate gradient method and a limited storage quasi-Newton BFGS method are analyzed and modifications to deal with the bounds on the variables are suggested based on projected gradient devices with specific linesearches. Some practical models are presented for electric generation planning and fishery management, and the application of the code GRECO - Gradient REduit pour la Commande Optimale - is discussed.
Numerical solutions of a control problem governed by functional differential equations
Banks, H. T.; Thrift, P. R.; Burns, J. A.; Cliff, E. M.
1978-01-01
A numerical procedure is proposed for solving optimal control problems governed by linear retarded functional differential equations. The procedure is based on the idea of 'averaging approximations', due to Banks and Burns (1975). For illustration, numerical results generated on an IBM 370/158 computer, which demonstrate the rapid convergence of the method are presented.
A note on social security welfare with self-control problems
Bucciol, A.
2011-01-01
We develop an overlapping-generations model for a closed economy with uncertainty on labor income and mortality risk to show that unfunded social security programs may increase welfare in economies where agents are affected by self-control problems à la Gul and Pesendorfer (2001, Econometrica 69,
Dorn, T.; Yzermans, J.C.; Spreeuwenberg, P.M.; Zee, J. van der
2007-01-01
OBJECTIVE: Caregiving has been described in the literature as a risk factor for ill health in the carer. This controlled, prospective study examines the course of physical and mental health problems in parents of adolescent survivors of a mass burn incident. METHODS: Health information was extracted
Miller, William R.; And Others
1993-01-01
To investigate impact of counselor style, offered 2-session motivational checkup to 42 problem drinkers randomly assigned to 1 of 3 groups: immediate checkup with directive-confrontational counseling, immediate checkup with client-centered counseling, or waiting-list control. Clients receiving immediate checkup showed significant reduction in…
On two speed optimization problems for ships that sail in and out of emission control areas
DEFF Research Database (Denmark)
Fagerholt, Kjetil; Psaraftis, Harilaos N.
2015-01-01
This paper deals with two speed optimization problems for ships that sail in and out of Emission Control Areas (ECAs) with strict limits on sulfur emissions. For ships crossing in and out of ECAs, such as deep-sea vessels, one of the common options for complying with these limits is to burn heavy...
Solution of Constrained Optimal Control Problems Using Multiple Shooting and ESDIRK Methods
DEFF Research Database (Denmark)
Capolei, Andrea; Jørgensen, John Bagterp
2012-01-01
In this paper, we describe a novel numerical algorithm for solution of constrained optimal control problems of the Bolza type for stiff and/or unstable systems. The numerical algorithm combines explicit singly diagonally implicit Runge-Kutta (ESDIRK) integration methods with a multiple shooting...
Noether's Symmetry Theorem for Variational and Optimal Control Problems with Time Delay
Frederico, G. S. F.; Torres, D. F. M.
2012-01-01
We extend the DuBois-Reymond necessary optimality condition and Noether's symmetry theorem to the time delay variational setting. Both Lagrangian and Hamiltonian versions of Noether's theorem are proved, covering problems of the calculus of variations and optimal control with delays.
He, Jie; Degnan, Kathryn Amey; McDermott, Jennifer Martin; Henderson, Heather A.; Hane, Amie Ashley; Xu, Qinmei; Fox, Nathan A.
2010-01-01
The relations among infant anger reactivity, approach behavior, and frontal electroencephalogram (EEG) asymmetry, and their relations to inhibitory control and behavior problems in early childhood were examined within the context of a longitudinal study of temperament. Two hundred nine infants' anger expressions to arm restraint were observed at 4…
A new computer method for temperature measurement based on an optimal control problem
Damean, N.; Houkes, Z.; Regtien, P.P.L.
1996-01-01
A new computer method to measure extreme temperatures is presented. The method reduces the measurement of the unknown temperature to the solving of an optimal control problem, using a numerical computer. Based on this method, a new device for temperature measurement is built. It consists of a hardwa
H∞ control of systems with multiple I/O delays via decomposition to adobe problems
Meinsma, Gjerrit; Mirkin, Leonid
2005-01-01
The standard (four-block) H/sup /spl infin// control problem for systems with multiple input-output delays in the feedback loop is studied. The central idea is to see the multiple delay operator as a special series connection of elementary delay operators, called the adobe delay operators. The adobe
Dorn, T.; Yzermans, J.C.; Spreeuwenberg, P.M.; Zee, J. van der
2007-01-01
OBJECTIVE: Caregiving has been described in the literature as a risk factor for ill health in the carer. This controlled, prospective study examines the course of physical and mental health problems in parents of adolescent survivors of a mass burn incident. METHODS: Health information was extracted
Pathways to Problem Behaviors: Chaotic Homes, Parent and Child Effortful Control, and Parenting
Valiente, Carlos; Lemery-Chalfant, Kathryn; Reiser, Mark
2007-01-01
Guided by Belsky's and Eisenberg, Cumberland, and Spinrad's heuristic models, we tested a process model with hypothesized paths from parents' effortful control (EC) and family chaos to indices of parenting to children's EC, and finally children's externalizing problem behavior. Parents reported on all constructs and children (N = 188; M age = 9.55…
A note on social security welfare with self-control problems
A. Bucciol
2011-01-01
We develop an overlapping-generations model for a closed economy with uncertainty on labor income and mortality risk to show that unfunded social security programs may increase welfare in economies where agents are affected by self-control problems à la Gul and Pesendorfer (2001, Econometrica 69, 14
On the possibility of control restoration in some inverse problems of heat and mass transfer
Bilchenko, G. G.; Bilchenko, N. G.
2016-11-01
The hypersonic aircraft permeable surfaces effective heat protection problems are considered. The physic-chemical processes (the dissociation and the ionization) in laminar boundary layer of compressible gas are appreciated in mathematical model. The statements of direct problems of heat and mass transfer are given: according to preset given controls it is necessary to compute the boundary layer mathematical model parameters and determinate the local and total heat flows and friction forces and the power of blowing system. The A.A.Dorodnicyn's generalized integral relations method has been used as calculation basis. The optimal control - the blowing into boundary layer (for continuous functions) was constructed as the solution of direct problem in extreme statement with the use of this approach. The statement of inverse problems are given: the control laws ensuring the preset given local heat flow and local tangent friction are restored. The differences between the interpolation and the approximation statements are discussed. The possibility of unique control restoration is established and proved (in the stagnation point). The computational experiments results are presented.
Leonard, A.R.
1960-01-01
One of the first requisites for the intelligent planning of utilization and control of water and for the administration of laws relating to its use is data on the quantity, quality, and mode of occurrence of the available supplies. The collection, evaluation and interpretation, and publication of such data are among the primary functions of the U.S. Geological Survey. Since 1895 the Congress has made appropriations to the Survey for investigation of the water resources of the Nation. In 1929 the Congress adopted the policy of dollar-for-dollar cooperation with the States and local governmental agencies in water-resources investigations of the U.S. Geological Survey. In 1937 a program of ground-water investigations was started in cooperation with the Oklahoma Geological Survey, and in 1949 this program was expanded to include cooperation with the Oklahoma Planning and Resources Board. In 1957 the State Legislature created the Oklahoma Water Resources Board as the principal State water agency and it became the principal local cooperator. The Ground Water Branch of the U.S. Geological Survey collects, analyzes, and evaluates basic information on ground-water resources and prepares interpretive reports based on those data. Cooperative ground-water work was first concentrated in the Panhandle counties. During World War II most work was related to problems of water supply for defense requirements. Since 1945 detailed investigations of ground-water availability have been made in 11 areas, chiefly in the western and central parts of the State. In addition, water levels in more than 300 wells are measured periodically, principally in the western half of the State. In Oklahoma current studies are directed toward determining the source, occurrence, and availability of ground water and toward estimating the quantity of water and rate of replenishment to specific areas and water-bearing formations. Ground water plays an important role in the economy of the State. It is
Directory of Open Access Journals (Sweden)
DAHIYA, P.
2015-05-01
Full Text Available This paper presents the application of hybrid opposition based disruption operator in gravitational search algorithm (DOGSA to solve automatic generation control (AGC problem of four area hydro-thermal-gas interconnected power system. The proposed DOGSA approach combines the advantages of opposition based learning which enhances the speed of convergence and disruption operator which has the ability to further explore and exploit the search space of standard gravitational search algorithm (GSA. The addition of these two concepts to GSA increases its flexibility for solving the complex optimization problems. This paper addresses the design and performance analysis of DOGSA based proportional integral derivative (PID and fractional order proportional integral derivative (FOPID controllers for automatic generation control problem. The proposed approaches are demonstrated by comparing the results with the standard GSA, opposition learning based GSA (OGSA and disruption based GSA (DGSA. The sensitivity analysis is also carried out to study the robustness of DOGSA tuned controllers in order to accommodate variations in operating load conditions, tie-line synchronizing coefficient, time constants of governor and turbine. Further, the approaches are extended to a more realistic power system model by considering the physical constraints such as thermal turbine generation rate constraint, speed governor dead band and time delay.
Downs, C. M.; Nowicki, R. S.; Rains, M. C.; Kruse, S.
2015-12-01
In west-central Florida, wetland and lake distribution is strongly controlled by karst landforms. Sandhill wetlands and lakes are sand-filled upland basins whose water levels are groundwater driven. Lake dimensions only reach wetland edges during extreme precipitation events. Current wetland classification schemes are inappropriate for identifying sandhill wetlands due to their unique hydrologic regime and ecologic expression. As a result, it is difficult to determine whether or not a wetland is impacted by groundwater pumping, development, and climate change. A better understanding of subsurface structures and how they control the hydrologic regime is necessary for development of an identification and monitoring protocol. Long-term studies record vegetation diversity and distribution, shallow ground water levels and surface water levels. The overall goals are to determine the hydrologic controls (groundwater, seepage, surface water inputs). Most recently a series of geophysical surveys was conducted at select sites in Hernando and Pasco County, Florida. Electrical resistivity and ground penetrating radar were employed to image sand-filled basins and the top of the limestone bedrock and stratigraphy of wetland slopes, respectively. The deepest extent of these sand-filled basins is generally reflected in topography as shallow depressions. Resistivity along inundated wetlands suggests the pools are surface expressions of the surficial aquifer. However, possible breaches in confining clay layers beneath topographic highs between depressions are seen in resistivity profiles as conductive anomalies and in GPR as interruptions in otherwise continuous horizons. These data occur at sites where unconfined and confined water levels are in agreement, suggesting communication between shallow and deep groundwater. Wetland plants are observed outside the historic wetland boundary at many sites, GPR profiles show near-surface layers dipping towards the wetlands at a shallower
Chapter 6: Tree-compatible ground covers for reforestation and erosion control
J. Burger; V. Davis; C. Zipper; J. Skousen; C. Barton; P. Angel
2017-01-01
Productive native forests create economic value for landowners, produce raw materials for wood-based products, and provide benefits such as watershed control, water quality protection, carbon storage, wildlife habitat, and native plant diversity. Owners of lands mined for coal in the Appalachian region are increasingly interested in assuring that productive forests are...
Use of combined Shewhart-CUSUM control charts for ground water monitoring applications
Energy Technology Data Exchange (ETDEWEB)
Gibbons, R.D.
1999-10-01
Statistical properties of combined Shewhart-CUSUM control charts are examined in terms of the site-wide false positive rate, false negative rate, and average run length (i.e., the average number of sampling events that it takes to detect a significant exceedance). The effects of multiple comparisons (i.e., multiple monitoring wells and constituents), verification resampling, background sample size, and background updating are incorporated into the analysis. The effects of (1) verification resampling plans including no resampling, pass one resample, pass one of two resamples, and pass two of two resamples; (2) background sample sizes (n = 8, 12, 16, 20, and 24); and (3) multiple comparisons (k = 1 to 500 future comparisons) were examined. In addition, various alternative control limit factors (h = SCL = 4.5, 5.0, 5.5, and 6.0) were considered, where the control limit is {bar x} + hs. Results of simulations revealed that it is possible to balance site-wide false positive and false negative rates at low levels using combined Shewhart-CUSUM control charts. The results revealed that it is important to select the appropriate multiplier, verification resampling plan, number of background samples, and number of intervening samples prior to updating background.
Ground Truthing the 'Conventional Wisdom' of Lead Corrosion Control Using Mineralogical Analysis
For drinking water distribution systems (DWDS) with lead-bearing plumbing materials some form of corrosion control is typically necessary, with the goal of mitigating lead release by forming adherent, stable corrosion scales composed of low-solubility mineral phases. Conventional...
hp-Pseudospectral method for solving continuous-time nonlinear optimal control problems
Darby, Christopher L.
2011-12-01
In this dissertation, a direct hp-pseudospectral method for approximating the solution to nonlinear optimal control problems is proposed. The hp-pseudospectral method utilizes a variable number of approximating intervals and variable-degree polynomial approximations of the state within each interval. Using the hp-discretization, the continuous-time optimal control problem is transcribed to a finite-dimensional nonlinear programming problem (NLP). The differential-algebraic constraints of the optimal control problem are enforced at a finite set of collocation points, where the collocation points are either the Legendre-Gauss or Legendre-Gauss-Radau quadrature points. These sets of points are chosen because they correspond to high-accuracy Gaussian quadrature rules for approximating the integral of a function. Moreover, Runge phenomenon for high-degree Lagrange polynomial approximations to the state is avoided by using these points. The key features of the hp-method include computational sparsity associated with low-order polynomial approximations and rapid convergence rates associated with higher-degree polynomials approximations. Consequently, the hp-method is both highly accurate and computationally efficient. Two hp-adaptive algorithms are developed that demonstrate the utility of the hp-approach. The algorithms are shown to accurately approximate the solution to general continuous-time optimal control problems in a computationally efficient manner without a priori knowledge of the solution structure. The hp-algorithms are compared empirically against local (h) and global (p) collocation methods over a wide range of problems and are found to be more efficient and more accurate. The hp-pseudospectral approach developed in this research not only provides a high-accuracy approximation to the state and control of an optimal control problem, but also provides high-accuracy approximations to the costate of the optimal control problem. The costate is approximated by
Inverse heat transfer problem in digital temperature control in plate fin and tube heat exchangers
Taler, Dawid; Sury, Adam
2011-12-01
The aim of the paper is a steady-state inverse heat transfer problem for plate-fin and tube heat exchangers. The objective of the process control is to adjust the number of fan revolutions per minute so that the water temperature at the heat exchanger outlet is equal to a preset value. Two control techniques were developed. The first is based on the presented mathematical model of the heat exchanger while the second is a digital proportional-integral-derivative (PID) control. The first procedure is very stable. The digital PID controller becomes unstable if the water volumetric flow rate changes significantly. The developed techniques were implemented in digital control system of the water exit temperature in a plate fin and tube heat exchanger. The measured exit temperature of the water was very close to the set value of the temperature if the first method was used. The experiments showed that the PID controller works also well but becomes frequently unstable.
Effect of spaceflight hardware on the skeletal properties of ground control mice
Bateman, Ted; Lloyd, Shane; Dunlap, Alex; Ferguson, Virginia; Simske, Steven; Stodieck, Louis; Livingston, Eric
Introduction: Spaceflight experiments using mouse or rat models require habitats that are specifically designed for the microgravity environment. During spaceflight, rodents are housed in a specially designed stainless steel meshed cage with gravity-independent food and water delivery systems and constant airflow to push floating urine and feces towards a waste filter. Differences in the housing environment alone, not even considering the spaceflight environment itself, may lead to physiological changes in the animals contained within. It is important to characterize these cage differences so that results from spaceflight experiments can be more reliably compared to studies from other laboratories. Methods: For this study, we examined the effect of NASA's Animal Enclosure Module (AEM) spaceflight hardware on the skeletal properties of 8-week-old female C57BL/6J mice. This 13-day experiment, conducted on the ground, modeled the flight experiment profile of the CBTM-01 payload on STS-108, with standard vivarium-housed mice being compared to AEM-housed mice (n = 12/group). Functional differences were compared via mechanical testing, micro-hardness indentation, microcomputed tomography, and mineral/matrix composition. Cellular changes were examined by serum chemistry, histology, quantitative histomorphometry, and RT-PCR. A Student's t-test was utilized, with the level of Type I error set at 95 Results: There was no change in elastic, maximum, or fracture force mechanical properties at the femur mid-diaphysis, however, structural stiffness was -17.5 Conclusions: Housing mice in the AEM spaceflight hardware had minimal effects on femur cortical bone properties. However, trabecular bone at the proximal tibia in AEM mice experi-enced large increases in microarchitecture and mineral composition. Increases in bone density were accompanied by reductions in bone-forming osteoblasts and bone-resorbing osteoclasts, representing a general decline in bone turnover at this site
Nath, Mahendra; Pink, Maren; Zaleski, Jeffrey M
2005-01-19
The cross-coupling reaction of 2,3-dibromo-5,10,15,20-tetraphenylporphyrin with corresponding organostannanes in the presence of a Pd0 catalyst in THF at reflux temperature yields free base 2,3-dialkynylporphyrins 1a,c-e. The subsequent deprotection of trimethylsilyl group of 1a with TBAF in THF under aqueous conditions produces the 2,3-diethynyl-5,10,15,20-tetraphenylporphyrins 1b in 87% yield. Compounds 1a-d undergo zinc insertion upon treatment with Zn(OAc)2.2H2O in CHCl3/MeOH to give zinc(II) 2,3-dialkynyl-5,10,15,20-tetraphenylporphyrins (2a-d) in 70-92% yields. Thermal Bergman cyclization of 1a-e and 2a-d was studied in chlorobenzene and approximately 35-fold 1,4-cyclohexadiene at 120-210 degrees C. Compounds 1b and 2b with R = H react at lower temperature (120 degrees C) and produce cyclized products 3b and 4b in higher yields (65-70%) than their propyl, isopropyl, and phenyl analogues, with R = Ph being the most stable. Continuing in this trend, the -TMS derivatives 1a and 2a exhibit no reactivity even after heating at 190 degrees C in chlorobenzene/CHD for 24 h. Photolysis (at lambda >/= 395 nm) of 1b and 2b at 10 degrees C leads the formation of isolable picenoporphyrin products in 15 and 35% yields, respectively, in 72 h, whereas these compounds are stable in solution under same reaction conditions at 25 degrees C in the dark. Unlike thermolysis at 125 degrees C, which did not yield Bergman cyclized product for R = Ph, photolysis generated very small amounts of picenoporphyrin products (3c: 5%; 4c: 8% based on 1H NMR) as well as a mixture of reduced porphyrin products that were not separable. Thus, trends in the barrier to Bergman cyclization in the excited state exhibit the same trend as those observed in the ground state as a function of R-group. Finally, photolysis of 2b at 10 degrees C with lambda >/= 515 or 590 nm in benzene/iPrOH (4:1, 72 h) produces 4b in 15 and 6% isolated yields, indicating that conjugation of the enediyne unit into the
Directory of Open Access Journals (Sweden)
A. V. Khobin
2016-08-01
Full Text Available Non-stationary control objects, especially with varying transmission coefficient, are fairly common in practice. Creation of automatic control systems (ACS for them is topical issue. This task of creating ACS for these kind of control objects is more difficult than for stationary control objects (with constant parameters because process value deviations relative to set point value are caused not only by coordinate disturbances but also by parametric ones. The issue of offset absence order increase impact on the levels of stabilization and reference tracking errors traditionally is dealt with when making synthesis of stationary ACS, particularly follow-up and program systems. For analytical solution of the non-stationary ACS analysis and synthesis problems, which contain control objects with varying transmission coefficient ko(t, it is necessary to utilize mathematical methods of linear systems with varying parameters. They are based on the concept of parametric transfer function. At the same time analytical calculation of stabilization and reference tracking errors, even for steady processes, is, apparently, extremely difficult, because there were found no examples of solution to this problem in technical publications. Computer modeling is considered more productive. It does not allow to obtain analytical expressions for control errors. But computer experiment goal planning allows to mark out their basic features and to evaluate effective methods of decreasing these mistakes.