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Systems, Man and Cybernetics, 1995. Intelligent Systems for the 21st Century., IEEE International Conference on

Date 22-25 Oct. 1995

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Displaying Results 1 - 25 of 150
  • An interactive fuzzy satisficing method for multiobjective structured linear programs and its application

    Page(s): 4045 - 4050 vol.5
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    We present an interactive fuzzy satisficing method for multiobjective structured linear programs. By considering the imprecise nature of human judgements, we assume that the decision maker (DM) may have a fuzzy goal for each of the objective functions. Having elicited the corresponding linear membership functions, if the DM specifies the reference membership levels for all the membership functions, the corresponding Pareto optimal solution which is, in the minimax sense, nearest to the requirement can be obtained by solving the minimax problem. Here it is shown that the formulated minimax problem can be reduced to one master problem and a number of linear subproblems and the Pareto optimal solution together with the trade-off rate information between the membership functions can be obtained by applying the Dantzig-Wolfe decomposition method. In this way, the satisficing solution for the DM can be derived from Pareto optimal solutions by updating the current reference membership levels on the basis of the current levels of the membership functions together with the trade-off rates between the membership functions. View full abstract»

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  • Empirical data modeling and state estimation for a steam boiler system

    Page(s): 3943 - 3948 vol.5
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    This paper presents an empirical data modeling approach for a class of systems called quasi-linear. In addition, state estimation based on the identified system and the design of a robust feedback controller for a complex industrial application are included. A drum boiler steam generator system is selected as a prototype example of this class of nonlinear dynamic systems to be identified and to be controlled in a deterministic and stochastic environment. Simulation results indicate that the resulting controller shows a significant improvement over existing proportional-integral (PI) control, including reduced transient response, time delay tolerance and also robustness against full load range (large steam flow changes), for different characteristics exhibited by the input (feedwater) valve. The prominent feature of this method is that no specific model information is initially required throughout the identification and control of the nonlinear plant, and hence the method is suitable for both identifying and controlling of the critical industrial processes View full abstract»

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  • On the analysis of discrete event systems using continuous Petri nets

    Page(s): 4184 - 4189 vol.5
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    For the purpose of controlling discrete event systems (DES) modelled by variable speed continuous Petri nets (VSCPn), the authors propose in this paper a transformation of equations describing the marking time evolution in terms of state equations. The authors discuss the use of this representation View full abstract»

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  • Control of a class of nonlinear systems via linear controllers with application to robots

    Page(s): 4428 - 4433 vol.5
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    This paper deals with the control of nonlinear systems where a new idea is presented, the necessary theory is stated and applied to a well-known nonlinear system, the robot. The new idea is motivated by the complexity of nonlinear control methods and the ease of the well-established linear control. Here, it is not meant to approximate or neglect nonlinear effects but, on the contrary, to take them fully into account. This is done by estimating the nonlinear effects and compensating for them View full abstract»

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  • Workflow and cooperative problem solving in civil infrastructure management

    Page(s): 4575 - 4580 vol.5
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    The goals of Project CITY (Civil Infostructure TechnologY) are to provide a technology demonstration of information infrastructure for civil infrastructure management and to demonstrate the Team Engineering Analysis and Modeling (TEAM) methodology in the analysis, design, and evaluation of that information infrastructure. The community of practice of Project CITY is the Public Works Division at a major Army installation. This paper focuses on three concurrent aspects of the project: 1) Task analyses and knowledge requirements of the community; 2) Systematic surveys of the community with respect to interdependence, workflow, coordination, and technology use; and 3) Candidate technologies for coordination and information sharing in distributed systems (e.g., SWIFT, ACE, and ISAM) View full abstract»

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  • The role of automation in the integrated cockpit of tomorrow's general aviation aircraft

    Page(s): 4196 - 4200 vol.5
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    In the past 25 years, the general aviation (GA) industry has declined significantly. The National Aeronautics and Space Administration (NASA) has implemented the Advanced General Aviation Transport Experiments (AGATE) program, demonstrating its commitment in reviving the industry. The goal of this program is to incorporate new and emerging technologies into the development of an affordable, safer, and easier to fly GA aircraft. Recent technological advances, in particular, innovative use of global positioning system (GPS) based sensors, have made possible the development of affordable, highly automated flight systems. Depending on automation alone, however, without very careful assessment of human factors could very well complicate, rather than simplify, the flight operations. To achieve AGATE's goal will require additional research to ensure that the technological advances are put to the most advantageous use in the development of an appropriate integrated cockpit for the GA application View full abstract»

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  • More efficient genetic algorithm for solving optimization problems

    Page(s): 4515 - 4520 vol.5
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    Genetic algorithms (GA) are stochastic search techniques based on mechanics of natural selection and natural genetics. By using genetic operators and cumulative information, genetic algorithms prune the search space and generate a set of plausible solutions. This paper describes an efficient genetic algorithm defined as modified genetic algorithms (MGA). The proposed algorithms is developed by hybridising simple genetic algorithms (SGA) with simulated annealing (SA). In this proposed algorithm, all the conventional genetic operators, such as, selection, reproduction, crossover, mutation, have been used. But they have been modified by a set of new functions such as a selection function 1, a selection function 2, a mutation function, etc., which utilizes the concept of successive descent as seen in simulated annealing. In this way, MGA can be implemented to solve various optimization problems more accurately and quickly View full abstract»

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  • A study on signature verification using a new approach to genetic based machine learning

    Page(s): 4383 - 4386 vol.5
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    This paper presents a new method to find best features for signature verification. The new method uses a new coding method, a new crossover method, and a new GA method with a local improvement mechanism proposed by the authors. The new coding method is effective to absorb the intra-personal variability among true signatures. The new crossover method determines the number of partial curves chosen for the signature verification. The new GA approach is very efficient in improving the local portions of chromosomes. Experiments are done to show the effectiveness of the new method View full abstract»

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  • Figure-ground separation by a dynamical system

    Page(s): 4615 - 4620 vol.5
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    This paper describes a neural network inspired dynamical system approach to a perceptual grouping problem-figure-ground separation. In this approach, a nonlinear differential equation is defined at each pixel site and coupled with those at its neighbors. The steady state solution would determine whether a pixel is part of a salient structure or background noise. The neighborhood couplings are used to achieve spatial interactions that are essential to perceptual grouping, such as excitation and inhibition. Experimental results on the grouping of dots in synthetic and real-world images demonstrate the efficacy of the proposed approach View full abstract»

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  • Application of the Hopfield network in robust estimation of parametric membership sets for linear models

    Page(s): 3949 - 3953 vol.5
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    High computation rates can be achieved using artificial neural networks. Optimization problems can be solved by neural networks with feedback connections by employing a massive number of simple processing elements with high degree of connectivity between these elements. In this paper, an application of Hopfield neural networks in robust parametric estimation with unknown-but-bounded disturbance is presented. The internal parameters of the Hopfield neural network are obtained using the valid-subspace technique. These parameters are explicitly computed to assure the network convergence. A comparative analysis with other robust estimation methods is carried out by a simulation example View full abstract»

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  • Optimal adaptive control of uncertain stochastic linear systems

    Page(s): 4521 - 4526 vol.5
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    The problem of optimal control of stochastic linear time-invariant uncertain systems on finite time interval is formulated and solved. This optimal solution shows that previously published adaptive optimal control schemes and indirect adaptive control schemes do not need heuristics for their rationalization. It is shown that these schemes are suboptimal causal approximations of the optimal solution. The solution is achieved by the introduction of the state and parameters observability form (SPOF). This new canonical representation of linear time-invariant systems enables direct application of the existing LQR-LQG theory of control and estimation of discrete linear time-varying systems. The optimal solution is exact and non causal. It is composed of the a linear time varying optimal estimator of the augmented state composed of the state of the system and the parameters, and of the optimal LQR controller. The estimator is causal. The controller is non-causal. As causal approximation control schemes based on the SPOF and the certainty equivalence principle and separation theorems are presented View full abstract»

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  • Cluster validity for fuzzy criterion clustering

    Page(s): 4702 - 4705 vol.5
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (304 KB)  

    Defines a validity measure for fuzzy criterion clustering which is a novel approach to fuzzy clustering that in addition to being non-distance based addresses the cluster validity problem. The model is then recast as a bilevel fuzzy criterion clustering problem. The authors propose an algorithm for this model that solves both the validity and clustering problems. The authors' approach is validated via some sample problems View full abstract»

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  • Neural network based system modeling

    Page(s): 4387 - 4391 vol.5
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    A method of using multi-layer perceptrons (MLPs) for modeling complex nonlinear systems is investigated. The importance of pre-processing is crucial to the modeling stage. This includes classifying input/output data into different categories for training-data selection, as well as extracting key features of the data. In this paper a prototype problem, an inverted pendulum system, is simulated as a physical system to be identified. The discussion focuses on this problem although the ideas are generic View full abstract»

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  • Real design problems and real clients: a systems engineering senior design program

    Page(s): 4341 - 4345 vol.5
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    We describe the senior design program in Systems Engineering at the University of Virginia. This program serves philosophical capstone of our undergraduate curriculum. We also describe our experiences related to the implementation and execution of the program. The senior design courses provide a major apprenticeship experience for the students that involve them in real design problems while working with real clients. Working in groups of five to eight members, the students apply their classroom knowledge of systems analysis and design to open-ended problems and real applications. Our experience with the program for the first six years has led to considerable success, with numerous student design groups receiving commendations from clients View full abstract»

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  • Extracting contact parameters from tactile data using artificial neural networks

    Page(s): 3954 - 3959 vol.5
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    In this paper neural networks are used to recover contact parameters from tactile sensor data. Tactile sensors are typically modeled using linear elasticity. Even under strong assumptions, these models are very difficult to solve. The finite-element method (FEM) provides a more accurate and realistic alternative to construct and solve models of a tactile sensor. The solutions obtained using the FEM, however, are numerical and do not directly provide analytical relationships between the sensor output and the contact parameters. Artificial neural networks (ANN), therefore, provide an ideal method to model these relationships, whereby the stress distributions and the associated contact parameters serve as the training data. We describe in this paper our attempt at using ANN to compute the contact parameters of contact force (both tangential and normal), indenter width, and indenter position. Simulation results are presented to validate the proposed approach View full abstract»

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  • Analogy-based learning support environment of abstract knowledge

    Page(s): 4673 - 4678 vol.5
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    Proposes a computer support learning environment of novice workers who learn new concepts in their unfamiliar domains, especially abstract knowledge domains, such as computer operating systems. Based on cognitive science, the authors' system provides the virtual space of the zone of proximal development, that is, a machine expert neighbor which advises the novices in their daily works. When the novices encounter troubles and ask the system for countermeasures, the system advises by referring to the analogical concept in their familiar domains in the form of the document, figures, and/or videos. The novices can cruise in the relevant/similar knowledge space through the hypertext-like interface View full abstract»

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  • Fuzzy logic and the principle of least commitment in computer vision

    Page(s): 4621 - 4625 vol.5
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    The application of fuzzy logic to computer vision processes has grown rapidly. The appeal of such techniques stems, at least partially, from the fact that they naturally maintain multiple hypotheses to varying degrees until a crisp decision must be made. This satisfies the principle of least commitment, originally stated by David Man for the development of intelligent computer vision algorithms. In this paper, we demonstrate fuzzy set theory's support of this principle with three examples from midlevel vision View full abstract»

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  • Addressing the trained novice/expert performance gap in complex dynamic systems: a case-based intelligent tutoring system

    Page(s): 4557 - 4562 vol.5
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    Training operators for complex dynamic systems is an essential, but costly, endeavor. New operators need to learn declarative and procedural knowledge, and operational skill in order to safely and effectively perform functions required in complex work domains, e.g., nuclear power generation or aviation. Economic pressures, however, necessitate the adoption of training approaches and programs that produce competent performance in limited time. These approaches often lead to gaps between the level of performance of the newly trained operator (the trained novice) and the expert operator. This paper discusses the genesis of this gap and some of its effects on operation. A design for a case-based intelligent tutoring system is proposed for addressing this performance gap View full abstract»

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  • Using vision-based control techniques for grasping objects

    Page(s): 4434 - 4439 vol.5
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    We present additions to the controlled active vision framework that focus upon the autonomous grasping of a moving object in the manipulator's workspace. Our work extends the capabilities of an eye-in-hand robotic system beyond those as a “pointer” or a “camera orienter” to provide the flexibility required to robustly interact with the environment in the presence of uncertainty. The proposed work is experimentally verified using the Minnesota Robotic Visual Tracker (MRVT) to automatically select object features, to derive estimates of unknown environmental parameters, and to supply a control vector based upon these estimates to guide the manipulator in the grasping of a moving object. The system grasps objects in the manipulator's workspace without requiring the object to follow a specific trajectory and without requiring the object to maintain a specific orientation View full abstract»

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  • An automated mail sorting center

    Page(s): 4492 - 4496 vol.5
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    An automated mail sorting center has been modeled by means of high level Petri nets (hierarchical, colored, timed). The communication protocol has been modeled very extensively to show its correct behavior. Simulation of the colored timed Petri net has been used to obtain performance characteristics View full abstract»

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  • Reengineering the software acquisition process using developer off-the-shelf systems (DOTSS)

    Page(s): 3971 - 3976 vol.5
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    2 approaches to software development, namely, extensive use of commercial practices and reuse of software, are considered. Both a Secretary of Defense Memorandum and a Defense Science Board report have reinforced the former. In the latter area, the DoD and the NIST, as well as others, have emphasized the development of software components that will ultimately serve as building blocks for the software developer. In this paper, we introduce a reengineered software acquisition process called Developer Off-The-Shelf Systems (DOTSS) in which entire systems are reused. This process has the potential for software acquisition process reform with extensive savings in both time and cost. Leverage is gained by taking advantage of sunk investments as well as proven software development architectures and successes View full abstract»

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  • Operator interface testing of a space telerobotic system

    Page(s): 4065 - 4072 vol.5
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    The major goals for this hand controller study were to compare the performance and operator preferences for three hand controllers, evaluate the learning curves associated with each hand controller and to determine what, if any, effects of hand controller test order were present. The hand controllers tested included a joint position controller, a cartesian position controller and a resolved rate controller. Repeated structural connector assembly trials were conducted with three different controllers. Enough runs were performed with each hand controller to determine learning curves for each task and hand controller. Controllers were also grouped by ordered pairs to evaluate transference of learning from one to another. Two post-test questionnaires were completed by every test subject to evaluate operator preferences View full abstract»

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  • Analysis and resolution of singularities for a 5-DOF GRYPHON manipulator

    Page(s): 4416 - 4421 vol.5
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    Many industrial robots have only five axes. When a manipulator is approaching a singular configuration, a certain degree of freedom will be lost such that there are no feasible solutions of the manipulator to move into this singular direction. In this paper, the singularities of a 5-DOF GRYPHON manipulator are analyzed in detail and all the corresponding singular directions in task space are clearly identified. In order to resolve this singularity problem, on approach denoted Singularity Isolation plus Compact QP (SICQP) method is proposed. The SICQP method isolates the singular directions, maintains the exactness of the achievable directions and minimizes the tracking errors in the singular directions under the condition that feasible joint solutions must be obtained. The simulation results reveal that when a manipulator is near or at the singular points, the SICQP method may minimize the tracking errors to the extent possible View full abstract»

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  • Adaptive scheduling of fault-tolerant parallel programs with timing constraints

    Page(s): 4533 - 4538 vol.5
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    We propose an adaptive preemptive scheduler for scheduling external sporadic tasks in a multiprocessor real-time system. We first present a pre-run-time scheduler to schedule a fault-tolerant parallel program with precedence constraints. Every task in the parallel program consists of two subtasks, namely, mandatory and optional. During run-time we optimally schedule the external tasks using the proposed adaptive scheduler. The scheduler removes the minimum number of optionals from the pre-run-time schedule to accommodate the external tasks. The performance of the system due to use of fault-tolerance is also demonstrated View full abstract»

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  • Optimal energy reference observer-based torque tracking : a nonlinear feedback control in the αβ frame

    Page(s): 4446 - 4451 vol.5
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    This paper presents, as the main contribution, an observer-based control feedback for the torque tracking of induction motors, conceived in terms of optimal state reference trajectories. This control scheme extends the result of Seleme et al. (1994) by the inclusion of a state observer and by the use of the stationary αβ frame model for the feedback design. Inherent passivity and dissipativity properties of the model are used View full abstract»

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