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Sample records for redundancy expert system

  1. Fault-tolerant flight control system combining expert system and analytical redundancy concepts

    NASA Technical Reports Server (NTRS)

    Handelman, Dave

    1987-01-01

    This research involves the development of a knowledge-based fault-tolerant flight control system. A software architecture is presented that integrates quantitative analytical redundancy techniques and heuristic expert system problem solving concepts for the purpose of in-flight, real-time failure accommodation.

  2. Redundant motor drive system

    NASA Technical Reports Server (NTRS)

    Calvert, J. A. (Inventor)

    1980-01-01

    A drive system characterized by a base supporting a pair of pillars arranged in spaced parallelism, a shaft extended between and supported by the pillars for rotation about the longitudinal axis thereof, a worm gear affixed to the shaft and supported in coaxial relation therewith is described. A bearing housing of a sleeve like configuration is concentrically related to the shaft and is supported thereby for free rotation. A first and a second quiescent drive train, alternatively activatable, is provided for imparting rotation into said bearing housing. Each of the drive trains is characterized by a selectively energizable motor connected to a spur gear.

  3. Statistical Fault Detection & Diagnosis Expert System

    SciTech Connect

    Wegerich, Stephan

    1996-12-18

    STATMON is an expert system that performs real-time fault detection and diagnosis of redundant sensors in any industrial process requiring high reliability. After a training period performed during normal operation, the expert system monitors the statistical properties of the incoming signals using a pattern recognition test. If the test determines that statistical properties of the signals have changed, the expert system performs a sequence of logical steps to determine which sensor or machine component has degraded.

  4. Expert system technology

    NASA Technical Reports Server (NTRS)

    Prince, Mary Ellen

    1987-01-01

    The expert system is a computer program which attempts to reproduce the problem-solving behavior of an expert, who is able to view problems from a broad perspective and arrive at conclusions rapidly, using intuition, shortcuts, and analogies to previous situations. Expert systems are a departure from the usual artificial intelligence approach to problem solving. Researchers have traditionally tried to develop general modes of human intelligence that could be applied to many different situations. Expert systems, on the other hand, tend to rely on large quantities of domain specific knowledge, much of it heuristic. The reasoning component of the system is relatively simple and straightforward. For this reason, expert systems are often called knowledge based systems. The report expands on the foregoing. Section 1 discusses the architecture of a typical expert system. Section 2 deals with the characteristics that make a problem a suitable candidate for expert system solution. Section 3 surveys current technology, describing some of the software aids available for expert system development. Section 4 discusses the limitations of the latter. The concluding section makes predictions of future trends.

  5. Ethical Expert Systems

    PubMed Central

    Victoroff, Michael S.

    1985-01-01

    The title is a double entendre. The discussion approaches expert systems from two directions: “What ethical hazards are created by expert systems in medicine?” and “Would it be ethical to design an expert system for solving problems in bioethics?” Computers present new ethical problems to society, some of which are unprecedented. These can be categorized under several rubrics. The paper describes a rudimentary scheme for understanding ethical issues raised by computers, in general, and medical expert systems, in particular. It focuses on bioethical implications of AI in medicine; explores norms, assumptions and taboos; and highlights certain ethical pitfalls. Principles are elucidated, for building ethically sound systems. Finally, a proposal is discussed, for the design of an expert system for moral problem solving, and the ethical implications of this notion are analyzed.

  6. Statistical Fault Detection & Diagnosis Expert System

    Energy Science and Technology Software Center (ESTSC)

    1996-12-18

    STATMON is an expert system that performs real-time fault detection and diagnosis of redundant sensors in any industrial process requiring high reliability. After a training period performed during normal operation, the expert system monitors the statistical properties of the incoming signals using a pattern recognition test. If the test determines that statistical properties of the signals have changed, the expert system performs a sequence of logical steps to determine which sensor or machine component hasmore » degraded.« less

  7. Benchmarking expert system tools

    NASA Technical Reports Server (NTRS)

    Riley, Gary

    1988-01-01

    As part of its evaluation of new technologies, the Artificial Intelligence Section of the Mission Planning and Analysis Div. at NASA-Johnson has made timing tests of several expert system building tools. Among the production systems tested were Automated Reasoning Tool, several versions of OPS5, and CLIPS (C Language Integrated Production System), an expert system builder developed by the AI section. Also included in the test were a Zetalisp version of the benchmark along with four versions of the benchmark written in Knowledge Engineering Environment, an object oriented, frame based expert system tool. The benchmarks used for testing are studied.

  8. Redundant Strapdown Laser Gyro Navigation System

    NASA Technical Reports Server (NTRS)

    Mcpherson, B. W.; Walls, B. F.; White, J. B.

    1976-01-01

    For the last several years, NASA has pursued the development of low-cost high-reliability inertial navigation systems that would satisfy a broad spectrum of future space and avionics missions. Two specific programs have culminated in the construction of a Redundant Strapdown Laser Gyro Navigation System. These two programs were for development of a space ultrareliable modular computer (SUMC) and a redundant laser gyro inertial measurement unit (IMU). The SUMC is a digital computer that employs state-of-the-art large-scale integrated circuits configured in a functional modular breakdown. The redundant laser gyro IMU is a six-pack strapdown sensor package in a dodecahedron configuration which uses six laser gyros to provide incremental angular positions and six accelerometers for linear velocity outputs. The sensor arrangement allows automatic accommodation of two failures; a third failure can be tolerated provided it can be determined. The navigation system also includes redundant power supplies, built-in test-equipment (BITE) circuits for failure detection, and software which provides for navigation, redundancy management, and automatic calibration and alignment.

  9. Multiple Fault Isolation in Redundant Systems

    NASA Technical Reports Server (NTRS)

    Shakeri, M.; Pattipati, Krishna R.; Raghavan, V.; Patterson-Hine, Ann; Iverson, David L.

    1997-01-01

    We consider the problem of sequencing tests to isolate multiple faults in redundant (fault-tolerant) systems with minimum expected testing cost (time). It can be shown that single faults and minimal faults, i.e., minimum number of failures with a failure signature different from the union of failure signatures of individual failures, together with their failure signatures, constitute the necessary information for fault diagnosis in redundant systems. In this paper, we develop an algorithm to find all the minimal faults and their failure signatures. Then, we extend the Sure diagnostic strategies [1] of our previous work to diagnose multiple faults in redundant systems. The proposed algorithms and strategies are illustrated using several examples.

  10. Impact Of Redundancy On Undersea Lightwave Systems

    NASA Astrophysics Data System (ADS)

    Brewer, S. Theodore

    1990-01-01

    Undersea lightwave systems represent a fascinating and challenging application of photonics engineering. Economy, transmission quality and long-term reliability are the hallmarks of these new systems. The optical fiber medium offers very high channel capacity for voice and all other digitally encoded signals. The high capacity results in low cost per channel. Concerning transmission quality, today digital transmission on undersea cables carries signals halfway round the world with quiet, virtually error - free performance. Furthermore, the short, direct path of the undersea route minimizes signal delay, making a significant contribution to customer satisfaction with voice, data, video conferencing, and other interactive services. We needed to achieve these important advances in economy and quality of transmission, and yet deliver systems with the traditional 25 year life and high reliability. This was the dilemma, to achieve extraordinarily high reliability with technologies which lacked extensive high-reliability background. Redundancy in several forms allowed us to introduce this advanced technology with high confidence of meeting the goal of 25 years of reliable system service. Following some historical notes on undersea cables, we describe the forms and levels of redundancy used in AT&T's SL Undersea cable systems. We then indicate how redundancy was implemented and it's impact on system reliability. Finally, we do a bit of crystal gazing concerning redundancy and reliability in the rapidly evolving optical undersea cable network.

  11. Avionic expert systems

    NASA Technical Reports Server (NTRS)

    Golshani, Forouzan

    1988-01-01

    At the heart of any intelligent flight control system, there is a knowledge based expert system. The efficiency of these knowledge bases is one of the major factors in the success of aviation and space control systems. In the future, the speed and the capabilities of the expert system and their underlying data base(s) will be the limiting factors in the ability to build more accurate real time space controllers. A methodology is proposed for design and construction of such expert systems. It is noted that existing expert systems are inefficient (slow) in dealing with nontrivial real world situations that involve a vast collection of data. However, current data bases, which are fast in handling large amounts of data, cannot carry out intelligent tasks normally expected from an expert system. The system presented provides the power of deduction (reasoning) along with the efficient mechanisms for management of large data bases. In the system, both straight forward evaluation procedures and sophisticated inference mechanisms coexist. The design methodology is based on mathematics and logic, which ensures the correctness of the final product.

  12. A highly redundant robot system for inspection

    NASA Technical Reports Server (NTRS)

    Lee, Thomas S.; Ohms, Tim; Hayati, Samad

    1994-01-01

    The work on the serpentine inspection system at JPL is described. The configuration of the inspection system consists of 20 degrees of freedom in total. In particular, the design and development of the serpentine micromanipulator end-effector tool which has 12 degrees of freedom is described. The inspection system is used for application in JPL's Remote Surface Inspection project and as a research tool in redundant manipulator control.

  13. Autonomous power expert system

    NASA Technical Reports Server (NTRS)

    Walters, Jerry L.; Petrik, Edward J.; Roth, Mary Ellen; Truong, Long Van; Quinn, Todd; Krawczonek, Walter M.

    1990-01-01

    The Autonomous Power Expert (APEX) system was designed to monitor and diagnose fault conditions that occur within the Space Station Freedom Electrical Power System (SSF/EPS) Testbed. APEX is designed to interface with SSF/EPS testbed power management controllers to provide enhanced autonomous operation and control capability. The APEX architecture consists of three components: (1) a rule-based expert system, (2) a testbed data acquisition interface, and (3) a power scheduler interface. Fault detection, fault isolation, justification of probable causes, recommended actions, and incipient fault analysis are the main functions of the expert system component. The data acquisition component requests and receives pertinent parametric values from the EPS testbed and asserts the values into a knowledge base. Power load profile information is obtained from a remote scheduler through the power scheduler interface component. The current APEX design and development work is discussed. Operation and use of APEX by way of the user interface screens is also covered.

  14. Expert Systems Research.

    ERIC Educational Resources Information Center

    Duda, Richard O.; Shortliffe, Edward H.

    1983-01-01

    Discusses a class of artificial intelligence computer programs (often called "expert systems" because they address problems normally thought to require human specialists for their solution) intended to serve as consultants for decision making. Also discusses accomplishments (including information systematization in medical diagnosis and geology)…

  15. Restoring Redundancy to the MAP Propulsion System

    NASA Technical Reports Server (NTRS)

    O'Donnell, James R., Jr.; Davis, Gary T.; Ward, David K.; Bauer, Frank H. (Technical Monitor)

    2002-01-01

    The Microwave Anisotropy Probe (MAP) is a follow-on to the Differential Microwave Radiometer (DMR) instrument on the Cosmic Background Explorer (COBE). Due to the MAP project's limited mass, power, and financial resources, a traditional reliability concept including fully redundant components was not feasible. The MAP design employs selective hardware redundancy, along with backup software modes and algorithms, to improve the odds of mission success. In particular, MAP's propulsion system, which is used for orbit maneuvers and momentum management, uses eight thrusters positioned and oriented in such a way that its thruster-based attitude control modes can maintain three-axis attitude control in the event of the failure of any one thruster.

  16. Expert Systems Application In Manufacturing

    NASA Astrophysics Data System (ADS)

    Som, Pradip; Chitturi, Ramesh; Babu, A. J. G.

    1987-05-01

    Expert system, a special branch of Artificial Intelligence finds its way in the domain of manufacturing. This paper presents the basic ideas and features of the expert systems, problems in manufacturing and application of expert systems in manufacturing. As the process planning is an important phase in manufacturing, the suitability of expert systems for process planning area has been highlighted. Several expert systems, developed to solve manufacturing problems are also discussed in the paper.

  17. Expert systems: a classical introduction.

    PubMed

    Semmel, R D

    1988-01-01

    Expert systems are providing a means of solving complex problems that previously defied automation efforts. This paper explains what an expert system is and how one operates. Following a brief description of expert systems, the nature of computer problem-solving and the role of knowledge in that activity are discussed. A typical expert system architecture and common knowledge representation schemes are then described. Finally, the operation of a simple, rule-based expert system is illustrated. PMID:10288417

  18. ALICE Expert System

    NASA Astrophysics Data System (ADS)

    Ionita, C.; Carena, F.

    2014-06-01

    The ALICE experiment at CERN employs a number of human operators (shifters), who have to make sure that the experiment is always in a state compatible with taking Physics data. Given the complexity of the system and the myriad of errors that can arise, this is not always a trivial task. The aim of this paper is to describe an expert system that is capable of assisting human shifters in the ALICE control room. The system diagnoses potential issues and attempts to make smart recommendations for troubleshooting. At its core, a Prolog engine infers whether a Physics or a technical run can be started based on the current state of the underlying sub-systems. A separate C++ component queries certain SMI objects and stores their state as facts in a Prolog knowledge base. By mining the data stored in different system logs, the expert system can also diagnose errors arising during a run. Currently the system is used by the on-call experts for faster response times, but we expect it to be adopted as a standard tool by regular shifters during the next data taking period.

  19. Expert systems and fuzzy systems

    SciTech Connect

    Negoita, C.

    1985-01-01

    This book examines the design of the expert computer system and how fuzzy systems can be used to deal with imprecise information. As the author explores the effects of semantic systems on decision support systems, he asserts that the utilization of fuzzy set theory can help an expert system draw from its knowledge base more efficiently and therefore make more accurate and reliable decisions. The book includes realistic status reports in approximate reasoning and knowledge representation that are supported by a ''theory of categories'' mathematical approach. The differences between symbolic and semantic manipulation are outline, and detailed information is given on the actual theory of knowledge-based systems.

  20. Autonomous power expert system

    NASA Technical Reports Server (NTRS)

    Ringer, Mark J.; Quinn, Todd M.

    1990-01-01

    The goal of the Autonomous Power System (APS) program is to develop and apply intelligent problem solving and control technologies to the Space Station Freedom Electrical Power Systems (SSF/EPS). The objectives of the program are to establish artificial intelligence/expert system technology paths, to create knowledge based tools with advanced human-operator interfaces, and to integrate and interface knowledge-based and conventional control schemes. This program is being developed at the NASA-Lewis. The APS Brassboard represents a subset of a 20 KHz Space Station Power Management And Distribution (PMAD) testbed. A distributed control scheme is used to manage multiple levels of computers and switchgear. The brassboard is comprised of a set of intelligent switchgear used to effectively switch power from the sources to the loads. The Autonomous Power Expert System (APEX) portion of the APS program integrates a knowledge based fault diagnostic system, a power resource scheduler, and an interface to the APS Brassboard. The system includes knowledge bases for system diagnostics, fault detection and isolation, and recommended actions. The scheduler autonomously assigns start times to the attached loads based on temporal and power constraints. The scheduler is able to work in a near real time environment for both scheduling and dynamic replanning.

  1. Autonomous power expert system

    NASA Technical Reports Server (NTRS)

    Ringer, Mark J.; Quinn, Todd M.

    1990-01-01

    The goal of the Autonomous Power System (APS) program is to develop and apply intelligent problem solving and control technologies to the Space Station Freedom Electrical Power Systems (SSF/EPS). The objectives of the program are to establish artificial intelligence/expert system technology paths, to create knowledge based tools with advanced human-operator interfaces, and to integrate and interface knowledge-based and conventional control schemes. This program is being developed at the NASA-Lewis. The APS Brassboard represents a subset of a 20 KHz Space Station Power Management And Distribution (PMAD) testbed. A distributed control scheme is used to manage multiple levels of computers and switchgear. The brassboard is comprised of a set of intelligent switchgear used to effectively switch power from the sources to the loads. The Autonomous Power Expert System (APEX) portion of the APS program integrates a knowledge based fault diagnostic system, a power resource scheduler, and an interface to the APS Brassboard. The system includes knowledge bases for system diagnostics, fault detection and isolation, and recommended actions. The scheduler autonomously assigns start times to the attached loads based on temporal and power constraints. The scheduler is able to work in a near real time environment for both scheduling an dynamic replanning.

  2. Heat exchanger demonstration expert system

    NASA Technical Reports Server (NTRS)

    Bagby, D. G.; Cormier, R. A.

    1988-01-01

    A real-time expert system intended for detecting and diagnosing faults in a 20 kW microwave transmitter heat exchanger is described. The expert system was developed on a LISP machine, Incorporated (LMI), Lambda Plus computer using Process Intelligent Control (PICON) software. The Heat Exhanger Expert System was tested and debugged. Future applications and extensions of the expert system to transmitters, masers, and antenna subassemblies are discussed.

  3. Heat exchanger demonstration expert system

    NASA Astrophysics Data System (ADS)

    Bagby, D. G.; Cormier, R. A.

    1988-05-01

    A real-time expert system intended for detecting and diagnosing faults in a 20 kW microwave transmitter heat exchanger is described. The expert system was developed on a LISP machine, Incorporated (LMI), Lambda Plus computer using Process Intelligent Control (PICON) software. The Heat Exhanger Expert System was tested and debugged. Future applications and extensions of the expert system to transmitters, masers, and antenna subassemblies are discussed.

  4. Expert and Knowledge Based Systems.

    ERIC Educational Resources Information Center

    Demaid, Adrian; Edwards, Lyndon

    1987-01-01

    Discusses the nature and current state of knowledge-based systems and expert systems. Describes an expert system from the viewpoints of a computer programmer and an applications expert. Addresses concerns related to materials selection and forecasts future developments in the teaching of materials engineering. (ML)

  5. Expert System Software

    NASA Technical Reports Server (NTRS)

    1989-01-01

    C Language Integrated Production System (CLIPS) is a software shell for developing expert systems is designed to allow research and development of artificial intelligence on conventional computers. Originally developed by Johnson Space Center, it enables highly efficient pattern matching. A collection of conditions and actions to be taken if the conditions are met is built into a rule network. Additional pertinent facts are matched to the rule network. Using the program, E.I. DuPont de Nemours & Co. is monitoring chemical production machines; California Polytechnic State University is investigating artificial intelligence in computer aided design; Mentor Graphics has built a new Circuit Synthesis system, and Brooke and Brooke, a law firm, can determine which facts from a file are most important.

  6. Expert system development for probabilistic load simulation

    NASA Technical Reports Server (NTRS)

    Ho, H.; Newell, J. F.

    1991-01-01

    A knowledge based system LDEXPT using the intelligent data base paradigm was developed for the Composite Load Spectra (CLS) project to simulate the probabilistic loads of a space propulsion system. The knowledge base approach provides a systematic framework of organizing the load information and facilitates the coupling of the numerical processing and symbolic (information) processing. It provides an incremental development environment for building generic probabilistic load models and book keeping the associated load information. A large volume of load data is stored in the data base and can be retrieved and updated by a built-in data base management system. The data base system standardizes the data storage and retrieval procedures. It helps maintain data integrity and avoid data redundancy. The intelligent data base paradigm provides ways to build expert system rules for shallow and deep reasoning and thus provides expert knowledge to help users to obtain the required probabilistic load spectra.

  7. Does plant species richness guarantee the resilience of local medical systems? A perspective from utilitarian redundancy.

    PubMed

    Santoro, Flávia Rosa; Ferreira Júnior, Washington Soares; Araújo, Thiago Antônio de Souza; Ladio, Ana Haydée; Albuquerque, Ulysses Paulino

    2015-01-01

    Resilience is related to the ability of a system to adjust to disturbances. The Utilitarian Redundancy Model has emerged as a tool for investigating the resilience of local medical systems. The model determines the use of species richness for the same therapeutic function as a facilitator of the maintenance of these systems. However, predictions generated from this model have not yet been tested, and a lack of variables exists for deeper analyses of resilience. This study aims to address gaps in the Utilitarian Redundancy Model and to investigate the resilience of two medical systems in the Brazilian semi-arid zone. As a local illness is not always perceived in the same way that biomedicine recognizes, the term "therapeutic targets" is used for perceived illnesses. Semi-structured interviews with local experts were conducted using the free-listing technique to collect data on known medicinal plants, usage preferences, use of redundant species, characteristics of therapeutic targets, and the perceived severity for each target. Additionally, participatory workshops were conducted to determine the frequency of targets. The medical systems showed high species richness but low levels of species redundancy. However, if redundancy was present, it was the primary factor responsible for the maintenance of system functions. Species richness was positively associated with therapeutic target frequencies and negatively related to target severity. Moreover, information about redundant species seems to be largely idiosyncratic; this finding raises questions about the importance of redundancy for resilience. We stress the Utilitarian Redundancy Model as an interesting tool to be used in studies of resilience, but we emphasize that it must consider the distribution of redundancy in terms of the treatment of important illnesses and the sharing of information. This study has identified aspects of the higher and lower vulnerabilities of medical systems, adding variables that should be

  8. Does Plant Species Richness Guarantee the Resilience of Local Medical Systems? A Perspective from Utilitarian Redundancy

    PubMed Central

    Santoro, Flávia Rosa

    2015-01-01

    Resilience is related to the ability of a system to adjust to disturbances. The Utilitarian Redundancy Model has emerged as a tool for investigating the resilience of local medical systems. The model determines the use of species richness for the same therapeutic function as a facilitator of the maintenance of these systems. However, predictions generated from this model have not yet been tested, and a lack of variables exists for deeper analyses of resilience. This study aims to address gaps in the Utilitarian Redundancy Model and to investigate the resilience of two medical systems in the Brazilian semi-arid zone. As a local illness is not always perceived in the same way that biomedicine recognizes, the term “therapeutic targets” is used for perceived illnesses. Semi-structured interviews with local experts were conducted using the free-listing technique to collect data on known medicinal plants, usage preferences, use of redundant species, characteristics of therapeutic targets, and the perceived severity for each target. Additionally, participatory workshops were conducted to determine the frequency of targets. The medical systems showed high species richness but low levels of species redundancy. However, if redundancy was present, it was the primary factor responsible for the maintenance of system functions. Species richness was positively associated with therapeutic target frequencies and negatively related to target severity. Moreover, information about redundant species seems to be largely idiosyncratic; this finding raises questions about the importance of redundancy for resilience. We stress the Utilitarian Redundancy Model as an interesting tool to be used in studies of resilience, but we emphasize that it must consider the distribution of redundancy in terms of the treatment of important illnesses and the sharing of information. This study has identified aspects of the higher and lower vulnerabilities of medical systems, adding variables that

  9. Expert Systems in Reference Services.

    ERIC Educational Resources Information Center

    Roysdon, Christine, Ed.; White, Howard D., Ed.

    1989-01-01

    Eleven articles introduce expert systems applications in library and information science, and present design and implementation issues of system development for reference services. Topics covered include knowledge based systems, prototype development, the use of artificial intelligence to remedy current system inadequacies, and an expert system to…

  10. Spacecraft environmental anomalies expert system

    NASA Technical Reports Server (NTRS)

    Koons, H. C.; Gorney, D. J.

    1988-01-01

    A microcomputer-based expert system is being developed at the Aerospace Corporation Space Sciences Laboratory to assist in the diagnosis of satellite anomalies caused by the space environment. The expert system is designed to address anomalies caused by surface charging, bulk charging, single event effects and total radiation dose. These effects depend on the orbit of the satellite, the local environment (which is highly variable), the satellite exposure time and the hardness of the circuits and components of the satellite. The expert system is a rule-based system that uses the Texas Instruments Personal Consultant Plus expert system shell. The completed expert system knowledge base will include 150 to 200 rules, as well as a spacecraft attributes database, an historical spacecraft anomalies database, and a space environment database which is updated in near real-time. Currently, the expert system is undergoing development and testing within the Aerospace Corporation Space Sciences Laboratory.

  11. Expert Antiskid System

    NASA Astrophysics Data System (ADS)

    Matsumoto, N.; Kuraoka, H.; Ohka, N.; Ohba, M.; Tabe, T.

    1987-10-01

    In this paper we discuss how to generate the command value for the optimal regulator in an automotive antiskid system. First, the behavior of the vehicle at braking is expressed as a mathematical model with the formulation by physical consideration and identification of the hydraulic system by statistical methods. An optimal regulator with additional integral is applied to the automotive antiskid control in order to make the each wheel speed follow any command value. However, the desired command value to stop the vehicle efficiently and stably is dependent on ambiguous road surface conditions. Thus, how to determine the desired command value under the moment-to-moment conditions is most important. A method for inferring the conditions is developed using fuzzy logic, with three fuzzy variables expressing the conditions adequately. On the basis of the inference, the ideal command values are generated. Outstanding control performance and good adaptability are obtained in vehicle experiments. Consequently, the Expert Antiskid System, employing modern control theory and fuzzy logic, can stop a vehicle efficiently and stably under any condition.

  12. Expert Systems and Document Handling.

    ERIC Educational Resources Information Center

    Edmonds, Ernest

    1987-01-01

    Describes significant attributes of expert systems, contrasts them to conventional computer systems, and provides an overview of the R1 expert system used by Digital Equipment Corporation (DEC) to put together operational systems that meet customers' requirements. Document handling, particularly pictures and images in documents, is also briefly…

  13. Expert Systems for the Analytical Laboratory.

    ERIC Educational Resources Information Center

    de Monchy, Allan R.; And Others

    1988-01-01

    Discusses two computer problem solving programs: rule-based expert systems and decision analysis expert systems. Explores the application of expert systems to automated chemical analyses. Presents six factors to consider before using expert systems. (MVL)

  14. Intelligent redundant actuation system requirements and preliminary system design

    NASA Technical Reports Server (NTRS)

    Defeo, P.; Geiger, L. J.; Harris, J.

    1985-01-01

    Several redundant actuation system configurations were designed and demonstrated to satisfy the stringent operational requirements of advanced flight control systems. However, this has been accomplished largely through brute force hardware redundancy, resulting in significantly increased computational requirements on the flight control computers which perform the failure analysis and reconfiguration management. Modern technology now provides powerful, low-cost microprocessors which are effective in performing failure isolation and configuration management at the local actuator level. One such concept, called an Intelligent Redundant Actuation System (IRAS), significantly reduces the flight control computer requirements and performs the local tasks more comprehensively than previously feasible. The requirements and preliminary design of an experimental laboratory system capable of demonstrating the concept and sufficiently flexible to explore a variety of configurations are discussed.

  15. Engineering monitoring expert system's developer

    NASA Technical Reports Server (NTRS)

    Lo, Ching F.

    1991-01-01

    This research project is designed to apply artificial intelligence technology including expert systems, dynamic interface of neural networks, and hypertext to construct an expert system developer. The developer environment is specifically suited to building expert systems which monitor the performance of ground support equipment for propulsion systems and testing facilities. The expert system developer, through the use of a graphics interface and a rule network, will be transparent to the user during rule constructing and data scanning of the knowledge base. The project will result in a software system that allows its user to build specific monitoring type expert systems which monitor various equipments used for propulsion systems or ground testing facilities and accrues system performance information in a dynamic knowledge base.

  16. Restoring Redundancy to the MAP Propulsion System

    NASA Technical Reports Server (NTRS)

    ODonnell, James R., Jr.; Davis, Gary T.; Ward, David K.; Bauer, F. (Technical Monitor)

    2002-01-01

    The Microwave Anisotropy Probe is a follow-on to the Differential Microwave Radiometer instrument on the Cosmic Background Explorer. Sixteen months before launch, it was discovered that from the time of the critical design review, configuration changes had resulted in a significant migration of the spacecraft's center of mass. As a result, the spacecraft no longer had a viable backup control mode in the event of a failure of the negative pitch axis thruster. Potential solutions to this problem were identified, such as adding thruster plume shields to redirect thruster torque, adding mass to, or removing it from, the spacecraft, adding an additional thruster, moving thrusters, bending thrusters (either nozzles or propellant tubing), or accepting the loss of redundancy for the thruster. The impacts of each solution, including effects on the mass, cost, and fuel budgets, as well as schedule, were considered, and it was decided to bend the thruster propellant tubing of the two roll control thrusters, allowing that pair to be used for back-up control in the negative pitch axis. This paper discusses the problem and the potential solutions, and documents the hardware and software changes that needed to be made to implement the chosen solution. Flight data is presented to show the propulsion system on-orbit performance.

  17. Redundant single event upset supression system

    DOEpatents

    Hoff, James R.

    2006-04-04

    CMOS transistors are configured to operate as either a redundant, SEU-tolerant, positive-logic, cross-coupled Nor Gate SR-flip flop or a redundant, SEU-tolerant, negative-logic, cross-coupled Nand Gate SR-flip flop. The register can operate as a memory, and further as a memory that can overcome the effects of radiation. As an SR-flip flop, the invention can be altered into any known type of latch or flip-flop by the application of external logic, thereby extending radiation tolerance to devices previously incapable of radiation tolerance. Numerous registers can be logically connected and replicated thereby being electronically configured to operate as a redundant circuit.

  18. Triple redundant computer system/display and keyboard subsystem interface

    NASA Technical Reports Server (NTRS)

    Gulde, F. J.

    1973-01-01

    Interfacing of the redundant display and keyboard subsystem with the triple redundant computer system is defined according to space shuttle design. The study is performed in three phases: (1) TRCS configuration and characteristics identification; (2) display and keyboard subsystem configuration and characteristics identification, and (3) interface approach definition.

  19. Expert Systems and Special Education.

    ERIC Educational Resources Information Center

    Hofmeister, Alan M.; Ferrara, Joseph M.

    The application of artificial intelligence to the problems of education is examined. One of the most promising areas in artificial intelligence is expert systems technology which engages the user in a problem-solving diaglogue. Some of the characteristics that make expert systems "intelligent" are identified and exemplified. The rise of expert…

  20. Expert Systems and Medical Education.

    ERIC Educational Resources Information Center

    Educational Researcher, 1988

    1988-01-01

    Expert systems are computerized databases that can diagnose and recommend treatment for persons who are ill. The database contains information on more than 7,600 diseases generated from exhaustive questioning of experts. These systems supplement human expertise but do not replace the good teaching of physicians. (VM)

  1. Threat expert system technology advisor

    NASA Technical Reports Server (NTRS)

    Kurrasch, E. R.; Tripp, L. R.

    1987-01-01

    A prototype expert system was developed to determine the feasibility of using expert system technology to enhance the performance and survivability of helicopter pilots in a combat threat environment while flying NOE (Nap of the Earth) missions. The basis for the concept is the potential of using an Expert System Advisor to reduce the extreme overloading of the pilot who flies NOE mission below treetop level at approximately 40 knots while performing several other functions. The ultimate goal is to develop a Threat Expert System Advisor which provides threat information and advice that are better than even a highly experienced copilot. The results clearly show that the NOE pilot needs all the help in decision aiding and threat situation awareness that he can get. It clearly shows that heuristics are important and that an expert system for combat NOE helicopter missions can be of great help to the pilot in complex threat situations and in making decisions.

  2. Expert systems for personnel assignment

    SciTech Connect

    Hardee, J.L.; Liepins, G.

    1986-01-01

    In order to reduce stress on assignment personnel (detailers) and ensure maximum fairness and consistency in the Navy's personnel assignment process, The Navy Military Personnel Command (NMPC) has begun to explore the potential use of expert systems to supplement current manual and computerized distribution methods. The Detailer's Assistant expert system is being developed to improve the detailers' ability to satisfy the needs of their constituents and Navy management. An initial prototype of the Detailer's Assistant is now being evaluated. Numerous upgrades and extensions should lead to an operational system in the near future. Further development to a production system will involve additional research in machine learning, intelligent database methods, and cooperating expert systems.

  3. Expert Systems in Clinical Microbiology

    PubMed Central

    Winstanley, Trevor; Courvalin, Patrice

    2011-01-01

    Summary: This review aims to discuss expert systems in general and how they may be used in medicine as a whole and clinical microbiology in particular (with the aid of interpretive reading). It considers rule-based systems, pattern-based systems, and data mining and introduces neural nets. A variety of noncommercial systems is described, and the central role played by the EUCAST is stressed. The need for expert rules in the environment of reset EUCAST breakpoints is also questioned. Commercial automated systems with on-board expert systems are considered, with emphasis being placed on the “big three”: Vitek 2, BD Phoenix, and MicroScan. By necessity and in places, the review becomes a general review of automated system performances for the detection of specific resistance mechanisms rather than focusing solely on expert systems. Published performance evaluations of each system are drawn together and commented on critically. PMID:21734247

  4. Expert systems in clinical microbiology.

    PubMed

    Winstanley, Trevor; Courvalin, Patrice

    2011-07-01

    This review aims to discuss expert systems in general and how they may be used in medicine as a whole and clinical microbiology in particular (with the aid of interpretive reading). It considers rule-based systems, pattern-based systems, and data mining and introduces neural nets. A variety of noncommercial systems is described, and the central role played by the EUCAST is stressed. The need for expert rules in the environment of reset EUCAST breakpoints is also questioned. Commercial automated systems with on-board expert systems are considered, with emphasis being placed on the "big three": Vitek 2, BD Phoenix, and MicroScan. By necessity and in places, the review becomes a general review of automated system performances for the detection of specific resistance mechanisms rather than focusing solely on expert systems. Published performance evaluations of each system are drawn together and commented on critically. PMID:21734247

  5. Diverse Redundant Systems for Reliable Space Life Support

    NASA Technical Reports Server (NTRS)

    Jones, Harry W.

    2015-01-01

    Reliable life support systems are required for deep space missions. The probability of a fatal life support failure should be less than one in a thousand in a multi-year mission. It is far too expensive to develop a single system with such high reliability. Using three redundant units would require only that each have a failure probability of one in ten over the mission. Since the system development cost is inverse to the failure probability, this would cut cost by a factor of one hundred. Using replaceable subsystems instead of full systems would further cut cost. Using full sets of replaceable components improves reliability more than using complete systems as spares, since a set of components could repair many different failures instead of just one. Replaceable components would require more tools, space, and planning than full systems or replaceable subsystems. However, identical system redundancy cannot be relied on in practice. Common cause failures can disable all the identical redundant systems. Typical levels of common cause failures will defeat redundancy greater than two. Diverse redundant systems are required for reliable space life support. Three, four, or five diverse redundant systems could be needed for sufficient reliability. One system with lower level repair could be substituted for two diverse systems to save cost.

  6. Requirement analysis of an intelligent, redundant, actuation system

    NASA Technical Reports Server (NTRS)

    De Feo, P.; Shih, K. C.

    1986-01-01

    The reliability and fault tolerance requirements of integrated, critical, digital fly-by-wire control systems for advanced military and civil aircraft requires redundant, reconfigurable implementations of the actuation system. An effective way for controlling the actuators and implementing the required fault detection and reconfiguration strategies is by means of dedicated microprocessors. This paper describes a laboratory implementation of a flexible intelligent redundant actuation system capable of demonstrating the concept and analyzing a variety of configurations and technical issues.

  7. Quantitative knowledge acquisition for expert systems

    NASA Technical Reports Server (NTRS)

    Belkin, Brenda L.; Stengel, Robert F.

    1991-01-01

    A common problem in the design of expert systems is the definition of rules from data obtained in system operation or simulation. While it is relatively easy to collect data and to log the comments of human operators engaged in experiments, generalizing such information to a set of rules has not previously been a direct task. A statistical method is presented for generating rule bases from numerical data, motivated by an example based on aircraft navigation with multiple sensors. The specific objective is to design an expert system that selects a satisfactory suite of measurements from a dissimilar, redundant set, given an arbitrary navigation geometry and possible sensor failures. The systematic development is described of a Navigation Sensor Management (NSM) Expert System from Kalman Filter convariance data. The method invokes two statistical techniques: Analysis of Variance (ANOVA) and the ID3 Algorithm. The ANOVA technique indicates whether variations of problem parameters give statistically different covariance results, and the ID3 algorithms identifies the relationships between the problem parameters using probabilistic knowledge extracted from a simulation example set. Both are detailed.

  8. Parallel processing and expert systems

    NASA Technical Reports Server (NTRS)

    Lau, Sonie; Yan, Jerry C.

    1991-01-01

    Whether it be monitoring the thermal subsystem of Space Station Freedom, or controlling the navigation of the autonomous rover on Mars, NASA missions in the 1990s cannot enjoy an increased level of autonomy without the efficient implementation of expert systems. Merely increasing the computational speed of uniprocessors may not be able to guarantee that real-time demands are met for larger systems. Speedup via parallel processing must be pursued alongside the optimization of sequential implementations. Prototypes of parallel expert systems have been built at universities and industrial laboratories in the U.S. and Japan. The state-of-the-art research in progress related to parallel execution of expert systems is surveyed. The survey discusses multiprocessors for expert systems, parallel languages for symbolic computations, and mapping expert systems to multiprocessors. Results to date indicate that the parallelism achieved for these systems is small. The main reasons are (1) the body of knowledge applicable in any given situation and the amount of computation executed by each rule firing are small, (2) dividing the problem solving process into relatively independent partitions is difficult, and (3) implementation decisions that enable expert systems to be incrementally refined hamper compile-time optimization. In order to obtain greater speedups, data parallelism and application parallelism must be exploited.

  9. Cathodic protection diagnostic expert system

    SciTech Connect

    Van Blaricum, V.L.; Kumar, A.; Park, Y.T.

    1994-12-31

    A knowledge-based diagnostic system called CP Diagnostic has been developed for troubleshooting sacrificial and impressed current cathodic protection systems. The expert system is designed to work in conjunction with the CP Diagnostic database system, which stores inventory and field measurement information for CP systems and flags problem areas. When a malfunction is detected, the expert system queries the user and the companion inventory and field measurement databases to determine its symptoms. The system will be described and examples of troubleshooting using the system will be presented.

  10. Parallel processing and expert systems

    NASA Technical Reports Server (NTRS)

    Yan, Jerry C.; Lau, Sonie

    1991-01-01

    Whether it be monitoring the thermal subsystem of Space Station Freedom, or controlling the navigation of the autonomous rover on Mars, NASA missions in the 90's cannot enjoy an increased level of autonomy without the efficient use of expert systems. Merely increasing the computational speed of uniprocessors may not be able to guarantee that real time demands are met for large expert systems. Speed-up via parallel processing must be pursued alongside the optimization of sequential implementations. Prototypes of parallel expert systems have been built at universities and industrial labs in the U.S. and Japan. The state-of-the-art research in progress related to parallel execution of expert systems was surveyed. The survey is divided into three major sections: (1) multiprocessors for parallel expert systems; (2) parallel languages for symbolic computations; and (3) measurements of parallelism of expert system. Results to date indicate that the parallelism achieved for these systems is small. In order to obtain greater speed-ups, data parallelism and application parallelism must be exploited.

  11. Nickel Hydrogen Battery Expert System

    NASA Astrophysics Data System (ADS)

    Johnson, Yvette B.; McCall, Kurt E.

    The Nickel Cadmium Battery Expert System-2, or 'NICBES-2', which was used by the NASA HST six-battery testbed, was subsequently converted into the Nickel Hydrogen Battery Expert System, or 'NICHES'. Accounts are presently given of this conversion process and future uses being contemplated for NICHES. NICHES will calculate orbital summary data at the end of each orbit, and store these files for trend analyses and rules-generation.

  12. The nutrition advisor expert system

    NASA Technical Reports Server (NTRS)

    Huse, Scott M.; Shyne, Scott S.

    1991-01-01

    The Nutrition Advisor Expert System (NAES) is an expert system written in the C Language Integrated Production System (CLIPS). NAES provides expert knowledge and guidance into the complex world of nutrition management by capturing the knowledge of an expert and placing it at the user's fingertips. Specifically, NAES enables the user to: (1) obtain precise nutrition information for food items; (2) perform nutritional analysis of meal(s), flagging deficiencies based upon the U.S. Recommended Daily Allowances; (3) predict possible ailments based upon observed nutritional deficiency trends; (4) obtain a top ten listing of food items for a given nutrient; and (5) conveniently upgrade the data base. An explanation facility for the ailment prediction feature is also provided to document the reasoning process.

  13. Cathodic protection diagnostic expert system

    SciTech Connect

    Van Blaricum, V.L.; Kumar, A. ); Park, Y.T. . Dept. of Computer Science)

    1994-12-01

    A knowledge-based diagnostic system has been developed for troubleshooting cathodic protection systems. The expert system is designed to work in conjunction with a database that stores inventory and field measurement information and flags problem areas. The system is described, and examples of troubleshooting using the system are presented.

  14. Graph transformation expert system (GTES)

    NASA Astrophysics Data System (ADS)

    Li, Guiquing; Ge, Qihong; Zhong, Luo; Xie, Weiping

    1996-03-01

    The design of many industrial and engineering systems can often be accomplished using flow graphs of various types. Examples include manufacturing processes and data processing applications, Graph Transformation Expert System, is an expert system which has been developed by WUT for applying techniques of artificial intelligence to the architectural design of data and signal processing systems. Software and hardware architectures may be defined for such systems using data flow graphs, in which nodes represent data processing steps and directed areas represent the `flow' of data between the processing steps. Starting with a user- defined generic processing graphic, this expert will transform the graph by applying transformation rules in order to specialize the processing graph to satisfy specified design goals and/or hardware constraints. Although the particular application for which this expert is designed is that of data and signal processing systems, it can provide an expert system framework for other problems specified graphically; for example, manufacturing systems, information systems, and product distribution systems.

  15. User interfaces to expert systems

    SciTech Connect

    Agarwal, A.; Emrich, M.L.

    1988-10-01

    Expert Systems are becoming increasingly popular in environments where the user is not well versed in computers or the subject domain. They offer expert advice and can also explain their lines of reasoning. As these systems are applied to highly technical areas, they become complex and large. Therefore, User Systems Interfaces (USIs) become critical. This paper discusses recent technologies that can be applied to improved user communication. In particular, bar menus/graphics, mouse interfaces, touch screens, and voice links will be highlighted. Their applications in the context of SOFTMAN (The Software Manager Apprentice) a knowledge-based system are discussed. 18 refs., 2 figs.

  16. Coupling expert systems and simulation

    NASA Technical Reports Server (NTRS)

    Kawamura, K.; Beale, G.; Padalkar, S.; Rodriguez-Moscoso, J.; Hsieh, B. J.; Vinz, F.; Fernandez, K. R.

    1988-01-01

    A prototype coupled system called NESS (NASA Expert Simulation System) is described. NESS assists the user in running digital simulations of dynamic systems, interprets the output data to performance specifications, and recommends a suitable series compensator to be added to the simulation model.

  17. Expert system application education project

    NASA Technical Reports Server (NTRS)

    Gonzelez, Avelino J.; Ragusa, James M.

    1988-01-01

    Artificial intelligence (AI) technology, and in particular expert systems, has shown potential applicability in many areas of operation at the Kennedy Space Center (KSC). In an era of limited resources, the early identification of good expert system applications, and their segregation from inappropriate ones can result in a more efficient use of available NASA resources. On the other hand, the education of students in a highly technical area such as AI requires an extensive hands-on effort. The nature of expert systems is such that proper sample applications for the educational process are difficult to find. A pilot project between NASA-KSC and the University of Central Florida which was designed to simultaneously address the needs of both institutions at a minimum cost. This project, referred to as Expert Systems Prototype Training Project (ESPTP), provided NASA with relatively inexpensive development of initial prototype versions of certain applications. University students likewise benefit by having expertise on a non-trivial problem accessible to them at no cost. Such expertise is indispensible in a hands-on training approach to developing expert systems.

  18. Nickel cadmium battery expert system

    NASA Technical Reports Server (NTRS)

    1986-01-01

    The applicability of artificial intelligence methodologies for the automation of energy storage management, in this case, nickel cadmium batteries, is demonstrated. With the Hubble Space Telescope Electrical Power System (HST/EPS) testbed as the application domain, an expert system was developed which incorporates the physical characterization of the EPS, in particular, the nickel cadmium batteries, as well as the human's operational knowledge. The expert system returns not only fault diagnostics but also status and advice along with justifications and explanations in the form of decision support.

  19. Expert Systems for Reference Work.

    ERIC Educational Resources Information Center

    Parrot, James R.

    1986-01-01

    Discussion of library reference work that may be suitable for use of expert systems focuses on (1) information and literature searches, and (2) requests to interpret bibliographic references and locate items listed. Systems and computer-assisted instruction modules designed for information retrieval at the University of Waterloo Library are…

  20. DRYNUT COMPUTER EXPERT SYSTEMS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of Drynut is to minimize the climatic environmental impact and economic risks in dryland peanut production while maximizing the economic return and improved peanut quality. Drynut uses new concepts, tools and management systems with finger tip computer-based technology to modify the i...

  1. Weather forecasting expert system study

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Weather forecasting is critical to both the Space Transportation System (STS) ground operations and the launch/landing activities at NASA Kennedy Space Center (KSC). The current launch frequency places significant demands on the USAF weather forecasters at the Cape Canaveral Forecasting Facility (CCFF), who currently provide the weather forecasting for all STS operations. As launch frequency increases, KSC's weather forecasting problems will be great magnified. The single most important problem is the shortage of highly skilled forecasting personnel. The development of forecasting expertise is difficult and requires several years of experience. Frequent personnel changes within the forecasting staff jeopardize the accumulation and retention of experience-based weather forecasting expertise. The primary purpose of this project was to assess the feasibility of using Artificial Intelligence (AI) techniques to ameliorate this shortage of experts by capturing aria incorporating the forecasting knowledge of current expert forecasters into a Weather Forecasting Expert System (WFES) which would then be made available to less experienced duty forecasters.

  2. Construction of control systems with diversified redundancy for electrical machines

    NASA Astrophysics Data System (ADS)

    Grigulewitsch, W.; Meffert, K.; Reuss, G.

    Redundant control systems for electrical machines were investigated from a safety engineering point of view. The boundary conditions and requirements for such systems, as well as the errors to be taken into account are discussed. The principle of diversified redundancy is explained. The peripheral commands are discussed. The degree of diversity, the use of programmable processing units, the use of hardware comparators, the signal processing, and the systems specifications testing are presented. Technical advice for the realization is given. Reliability, availability and cost are discussed.

  3. Expert System For Heat Exchanger

    NASA Technical Reports Server (NTRS)

    Bagby, D. Gordon; Cormier, Reginald A.

    1991-01-01

    Diagnosis simplified for non-engineers. Developmental expert-system computer program assists operator in controlling, monitoring operation, diagnosing malfunctions, and ordering repairs of heat-exchanger system dissipating heat generated by 20-kW radio transmitter. System includes not only heat exchanger but also pumps, fans, sensors, valves, reservoir, and associated plumbing. Program conceived to assist operator while avoiding cost of keeping engineer in full-time attendance. Similar programs developed for heating, ventilating, and air-conditioning systems.

  4. Expert systems for superalloy studies

    NASA Technical Reports Server (NTRS)

    Workman, Gary L.; Kaukler, William F.

    1990-01-01

    There are many areas in science and engineering which require knowledge of an extremely complex foundation of experimental results in order to design methodologies for developing new materials or products. Superalloys are an area which fit well into this discussion in the sense that they are complex combinations of elements which exhibit certain characteristics. Obviously the use of superalloys in high performance, high temperature systems such as the Space Shuttle Main Engine is of interest to NASA. The superalloy manufacturing process is complex and the implementation of an expert system within the design process requires some thought as to how and where it should be implemented. A major motivation is to develop a methodology to assist metallurgists in the design of superalloy materials using current expert systems technology. Hydrogen embrittlement is disasterous to rocket engines and the heuristics can be very complex. Attacking this problem as one module in the overall design process represents a significant step forward. In order to describe the objectives of the first phase implementation, the expert system was designated Hydrogen Environment Embrittlement Expert System (HEEES).

  5. IRES: image retrieval expert system

    NASA Astrophysics Data System (ADS)

    Liu Sheng, Olivia R.; Wang, Hui-Chin; Garcia, Hong-Mei C.

    1990-08-01

    Image Retrieval Expert System (IRES), a knowledge-based system for automatic image retrieval, is being prototyped at the University of Arizona (U of A). IRES is to couple with the distributed database system designed for Structured PACS (S-PACS)1 to achieve the high system performance required by radiologists. IRES encompasses the "intelligence" of multiple expert radiologists. The system will predict and migrate the "old" images needed for comparison purposes during radiological exam readings from slower or remote storage devices to the local buffers of workstations. The use of IRES with the PACS Distributed Database System (DDBS) is expected to shorten the PACS system response time, save the time of radiologists in selecting films, minimize the turnaround time of the exam interpretation function, and increase diagnostic effectiveness by providing relevant images automatically. This paper presents the implementation details of this IRES prototype.

  6. Expert System Development Methodology (ESDM)

    NASA Technical Reports Server (NTRS)

    Sary, Charisse; Gilstrap, Lewey; Hull, Larry G.

    1990-01-01

    The Expert System Development Methodology (ESDM) provides an approach to developing expert system software. Because of the uncertainty associated with this process, an element of risk is involved. ESDM is designed to address the issue of risk and to acquire the information needed for this purpose in an evolutionary manner. ESDM presents a life cycle in which a prototype evolves through five stages of development. Each stage consists of five steps, leading to a prototype for that stage. Development may proceed to a conventional development methodology (CDM) at any time if enough has been learned about the problem to write requirements. ESDM produces requirements so that a product may be built with a CDM. ESDM is considered preliminary because is has not yet been applied to actual projects. It has been retrospectively evaluated by comparing the methods used in two ongoing expert system development projects that did not explicitly choose to use this methodology but which provided useful insights into actual expert system development practices and problems.

  7. Redundant arm control in a supervisory and shared control system

    NASA Technical Reports Server (NTRS)

    Backes, Paul G.; Long, Mark K.

    1992-01-01

    The Extended Task Space Control approach to robotic operations based on manipulator behaviors derived from task requirements is described. No differentiation between redundant and non-redundant robots is made at the task level. The manipulation task behaviors are combined into a single set of motion commands. The manipulator kinematics are used subsequently in mapping motion commands into actuator commands. Extended Task Space Control is applied to a Robotics Research K-1207 seven degree-of-freedom manipulator in a supervisory telerobot system as an example.

  8. Psychology of developing and designing expert systems

    SciTech Connect

    Tonn, B.; MacGregor, D.

    1986-01-01

    This paper discusses psychological problems relevant to developing and designing expert systems. With respect to the former, the psychological literature suggests that several cognitive biases may affect the elicitation of a valid knowledge base from the expert. The literature also suggests that common expert system inference engines may be quite inconsistent with reasoning heuristics employed by experts. With respect to expert system user interfaces, care should be taken when eliciting uncertainty estimates from users, presenting system conclusions, and ordering questions.

  9. Intelligent interfaces for expert systems

    NASA Technical Reports Server (NTRS)

    Villarreal, James A.; Wang, Lui

    1988-01-01

    Vital to the success of an expert system is an interface to the user which performs intelligently. A generic intelligent interface is being developed for expert systems. This intelligent interface was developed around the in-house developed Expert System for the Flight Analysis System (ESFAS). The Flight Analysis System (FAS) is comprised of 84 configuration controlled FORTRAN subroutines that are used in the preflight analysis of the space shuttle. In order to use FAS proficiently, a person must be knowledgeable in the areas of flight mechanics, the procedures involved in deploying a certain payload, and an overall understanding of the FAS. ESFAS, still in its developmental stage, is taking into account much of this knowledge. The generic intelligent interface involves the integration of a speech recognizer and synthesizer, a preparser, and a natural language parser to ESFAS. The speech recognizer being used is capable of recognizing 1000 words of connected speech. The natural language parser is a commercial software package which uses caseframe instantiation in processing the streams of words from the speech recognizer or the keyboard. The systems configuration is described along with capabilities and drawbacks.

  10. Multiple Fault Isolation in Redundant Systems

    NASA Technical Reports Server (NTRS)

    Pattipati, Krishna R.; Patterson-Hine, Ann; Iverson, David

    1997-01-01

    Fault diagnosis in large-scale systems that are products of modern technology present formidable challenges to manufacturers and users. This is due to large number of failure sources in such systems and the need to quickly isolate and rectify failures with minimal down time. In addition, for fault-tolerant systems and systems with infrequent opportunity for maintenance (e.g., Hubble telescope, space station), the assumption of at most a single fault in the system is unrealistic. In this project, we have developed novel block and sequential diagnostic strategies to isolate multiple faults in the shortest possible time without making the unrealistic single fault assumption.

  11. Multiple Fault Isolation in Redundant Systems

    NASA Technical Reports Server (NTRS)

    Pattipati, Krishna R.

    1997-01-01

    Fault diagnosis in large-scale systems that are products of modem technology present formidable challenges to manufacturers and users. This is due to large number of failure sources in such systems and the need to quickly isolate and rectify failures with minimal down time. In addition, for fault-tolerant systems and systems with infrequent opportunity for maintenance (e.g., Hubble telescope, space station), the assumption of at most a single fault in the system is unrealistic. In this project, we have developed novel block and sequential diagnostic strategies to isolate multiple faults in the shortest possible time without making the unrealistic single fault assumption.

  12. 109. REDUNDANCY SYSTEM CONTROLS FOR UMBILICAL MAST RETRACTION AT LOWER ...

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

    109. REDUNDANCY SYSTEM CONTROLS FOR UMBILICAL MAST RETRACTION AT LOWER LEFT SIDE OF HYDRAULIC CONTROL PANEL IN UMBILICAL MAST PUMP ROOM (109), LSB (BLDG. 770) - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 West, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  13. 126. REDUNDANCY SYSTEM CONTROLS FOR UMBILICAL MAST RETRACTION AT LOWER ...

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

    126. REDUNDANCY SYSTEM CONTROLS FOR UMBILICAL MAST RETRACTION AT LOWER LEFT SIDE OF HYDRAULIC CONTROL PANEL IN UMBILICAL MAST PUMP ROOM (209), LSB (BLDG. 751) - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  14. Expert System for ASIC Imaging

    NASA Astrophysics Data System (ADS)

    Gupta, Shri N.; Arshak, Khalil I.; McDonnell, Pearse; Boyce, Conor; Duggan, Andrew

    1989-07-01

    With the developments in the techniques of artificial intelligence over the last few years, development of advisory, scheduling and similar class of problems has become very convenient using tools such as PROLOG. In this paper an expert system has been described which helps lithographers and process engineers in several ways. The methodology used is to model each work station according to its input, output and control parameters, combine these work stations in a logical sequence based on past experience and work out process schedule for a job. In addition, all the requirements vis-a-vis a particular job parameters are converted into decision rules. One example is the exposure time, develop time for a wafer with different feature sizes would be different. This expert system has been written in Turbo Prolog. By building up a large number of rules, one can tune the program to any facility and use it for as diverse applications as advisory help, trouble shooting etc. Leitner (1) has described an advisory expert system that is being used at National Semiconductor. This system is quite different from the one being reported in the present paper. The approach is quite different for one. There is stress on job flow and process for another.

  15. Lockheed L-1101 avionic flight control redundant systems

    NASA Technical Reports Server (NTRS)

    Throndsen, E. O.

    1976-01-01

    The Lockheed L-1011 automatic flight control systems - yaw stability augmentation and automatic landing - are described in terms of their redundancies. The reliability objectives for these systems are discussed and related to in-service experience. In general, the availability of the stability augmentation system is higher than the original design requirement, but is commensurate with early estimates. The in-service experience with automatic landing is not sufficient to provide verification of Category 3 automatic landing system estimated availability.

  16. Heat exchanger expert system logic

    NASA Technical Reports Server (NTRS)

    Cormier, R.

    1988-01-01

    The reduction is described of the operation and fault diagnostics of a Deep Space Network heat exchanger to a rule base by the application of propositional calculus to a set of logic statements. The value of this approach lies in the ease of converting the logic and subsequently implementing it on a computer as an expert system. The rule base was written in Process Intelligent Control software.

  17. Switching System for Redundant Power Supplies

    NASA Technical Reports Server (NTRS)

    Bradford, M.; Grant, R.; Parkinson, G.

    1986-01-01

    Load-transfer unit connects airborne computer to standby power supply in case primary supply fails. Concept adaptable to systems in which power interruptions cannot be tolerated; for example, computers with volatile memories, safety equipment, and precise timers. Load-transfer unit monitors voltages and load current. Microprocessor controls transistor switches that connect load to whichever power supply has highest priority and correct voltage.

  18. Expert Witness: A system for developing expert medical testimony

    NASA Technical Reports Server (NTRS)

    Lewandowski, Raymond; Perkins, David; Leasure, David

    1994-01-01

    Expert Witness in an expert system designed to assist attorneys and medical experts in determining the merit of medical malpractice claims in the area of obstetrics. It substitutes the time of the medical expert with the time of a paralegal assistant guided by the expert system during the initial investigation of the medical records and patient interviews. The product of the system is a narrative transcript containing important data, immediate conclusions from the data, and overall conclusions of the case that the attorney and medical expert use to make decisions about whether and how to proceed with the case. The transcript may also contain directives for gathering additional information needed for the case. The system is a modified heuristic classifier and is implemented using over 600 CLIPS rules together with a C-based user interface. The data abstraction and solution refinement are implemented directly using forward chaining production and matching. The use of CLIPS and C is essential to delivering a system that runs on a generic PC platform. The direct implementation in CLIPS together with locality of inference ensures that the system will scale gracefully. Two years of use has revealed no errors in the reasoning.

  19. Knowledge acquisition for expert systems using statistical methods

    NASA Technical Reports Server (NTRS)

    Belkin, Brenda L.; Stengel, Robert F.

    1991-01-01

    A common problem in the design of expert systems is the definition of rules from data obtained in system operation or simulation. A statistical method for generating rule bases from numerical data, motivated by an example based on aircraft navigation with multiple sensors is presented. The specific objective is to design an expert system that selects a satisfactory suite of measurements from a dissimilar, redundant set, given an arbitrary navigation geometry and possible sensor failures. The systematic development of a Navigation Sensor Management (NSM) Expert System from Kalman Filter covariance data is described. The development method invokes two statistical techniques: Analysis-of-Variance (ANOVA) and the ID3 algorithm. The ANOVA technique indicates whether variations of problem parameters give statistically different covariance results, and the ID3 algorithm identifies the relationships between the problem parameters using probabilistic knowledge extracted from a simulation example set.

  20. Enhanced, Partially Redundant Emergency Notification System

    NASA Technical Reports Server (NTRS)

    Pounds, Clark D.

    2005-01-01

    The Johnson Space Center Emergency Notification System (JENS) software utilizes pre-existing computation and communication infrastructure to augment a prior variable-tone, siren-based, outdoor alarm system, in order to enhance the ability to give notice of emergencies to employees working in multiple buildings. The JENS software includes a component that implements an administrative Web site. Administrators can grant and deny access to the administrative site and to an originator Web site that enables authorized individuals to quickly compose and issue alarms. The originator site also facilitates maintenance and review of alarms already issued. A custom client/server application program enables an originator to notify every user who is logged in on a Microsoft Windows-based desktop computer by means of a pop-up message that interrupts, but does not disrupt, the user s work. Alternatively or in addition, the originator can send an alarm message to recipients on an e-mail distribution list and/or can post the notice on an internal Web site. An alarm message can consist of (1) text describing the emergency and suggesting a course of action and (2) a replica of the corresponding audible outdoor alarm.

  1. Expert system for UNIX system reliability and availability enhancement

    NASA Astrophysics Data System (ADS)

    Xu, Catherine Q.

    1993-02-01

    Highly reliable and available systems are critical to the airline industry. However, most off-the-shelf computer operating systems and hardware do not have built-in fault tolerant mechanisms, the UNIX workstation is one example. In this research effort, we have developed a rule-based Expert System (ES) to monitor, command, and control a UNIX workstation system with hot-standby redundancy. The ES on each workstation acts as an on-line system administrator to diagnose, report, correct, and prevent certain types of hardware and software failures. If a primary station is approaching failure, the ES coordinates the switch-over to a hot-standby secondary workstation. The goal is to discover and solve certain fatal problems early enough to prevent complete system failure from occurring and therefore to enhance system reliability and availability. Test results show that the ES can diagnose all targeted faulty scenarios and take desired actions in a consistent manner regardless of the sequence of the faults. The ES can perform designated system administration tasks about ten times faster than an experienced human operator. Compared with a single workstation system, our hot-standby redundancy system downtime is predicted to be reduced by more than 50 percent by using the ES to command and control the system.

  2. Expert System for UNIX System Reliability and Availability Enhancement

    NASA Technical Reports Server (NTRS)

    Xu, Catherine Q.

    1993-01-01

    Highly reliable and available systems are critical to the airline industry. However, most off-the-shelf computer operating systems and hardware do not have built-in fault tolerant mechanisms, the UNIX workstation is one example. In this research effort, we have developed a rule-based Expert System (ES) to monitor, command, and control a UNIX workstation system with hot-standby redundancy. The ES on each workstation acts as an on-line system administrator to diagnose, report, correct, and prevent certain types of hardware and software failures. If a primary station is approaching failure, the ES coordinates the switch-over to a hot-standby secondary workstation. The goal is to discover and solve certain fatal problems early enough to prevent complete system failure from occurring and therefore to enhance system reliability and availability. Test results show that the ES can diagnose all targeted faulty scenarios and take desired actions in a consistent manner regardless of the sequence of the faults. The ES can perform designated system administration tasks about ten times faster than an experienced human operator. Compared with a single workstation system, our hot-standby redundancy system downtime is predicted to be reduced by more than 50 percent by using the ES to command and control the system.

  3. "Auctoritas" psychiatric expert system shell.

    PubMed

    Kovács, M; Juranovics, J

    1995-01-01

    We present a short description of a complex psychiatric computer expert system, including functions that help the physicians and the hospital staff in the administrative, diagnostic, therapeutic, statistical, and scientific work. There are separate data-storing, health insurance-supporting, or simple advisory programs, but we can not avail a system--in our country--that provides us with all these functions together. Hence the aim of our program is to produce a universal computer system that makes the patients' long distance follow-up possible. Our diagnostic expert system shell, which is appropriate for using the symptoms and criteria scheme of the internationally accepted diagnostic systems such as DSM and ICD, helps to archive homogeneous, up-to-date psychiatric nosology; this is essential for the correct diagnostic, statistical, and scientific work. Let us introduce our expert system. It consists of four parts: administration, diagnostic decision support system, activities concerning treatment, and statistics. The part called "Administration" contains all data about actual and emitted in-patients and out-patients, including their particulars and data necessary for health insurance (duration of treatment, diagnosis); here we find and edit medical documents. The most important part of the "Auctoritas" system is the "Diagnostic decision support system." In practice, expert systems use decision trees with yes-no logic, fuzzy logic, and pattern matching on the basis of the method of deduction; and backward chaining or forward chaining on the basis of the direction of deduction. Our system uses the methods of fuzzy logic and backward chaining. In other medical disciplines, good results are achieved by applying the pattern matching method; to make validity and verification researches, however, these systems are inappropriate. The diagnoses relying on the up-to-date psychiatric diagnostic systems--DSM-IV and ICD-X--are based on classical logic and can be correctly

  4. Expert system for groundwater modeling

    SciTech Connect

    Venoge, T.P. de; Stauffer, T.B.; Medina, M.; Jacobs, T.

    1994-12-31

    Hazardous waste site remedial investigations and feasibility studies generally involve some degree of groundwater modeling. A plethora of models exist and most models are difficult to use. An expert system has been developed to lead the user to the appropriate model(s) based on responses to questions about site conditions and data availability. The system is menu driven, user friendly, and provides assistance in estimating input parameters where field measurements are lacking. The system contains twelve models, both analytical and numerical models, that are in the public domain. Some of the models included in the system are MOC, MODFLOW, BIOPLUME, RESSQ, TDAST and PLUME2D. Preprocessors and post processors have been written to permit easy data input and to provide understandable and interpretable data output. There are two versions of the expert system that are available. One version is a UNIX based system that works through the windows environment and provides excellent graphics capabilities. The other version is DOS based and will run on a 386 processor or higher system with 10 megabytes of available hard disk space.

  5. Fuzzy expert systems using CLIPS

    NASA Technical Reports Server (NTRS)

    Le, Thach C.

    1994-01-01

    This paper describes a CLIPS-based fuzzy expert system development environment called FCLIPS and illustrates its application to the simulated cart-pole balancing problem. FCLIPS is a straightforward extension of CLIPS without any alteration to the CLIPS internal structures. It makes use of the object-oriented and module features in CLIPS version 6.0 for the implementation of fuzzy logic concepts. Systems of varying degrees of mixed Boolean and fuzzy rules can be implemented in CLIPS. Design and implementation issues of FCLIPS will also be discussed.

  6. Superlinearly scalable noise robustness of redundant coupled dynamical systems

    NASA Astrophysics Data System (ADS)

    Kohar, Vivek; Kia, Behnam; Lindner, John F.; Ditto, William L.

    2016-03-01

    We illustrate through theory and numerical simulations that redundant coupled dynamical systems can be extremely robust against local noise in comparison to uncoupled dynamical systems evolving in the same noisy environment. Previous studies have shown that the noise robustness of redundant coupled dynamical systems is linearly scalable and deviations due to noise can be minimized by increasing the number of coupled units. Here, we demonstrate that the noise robustness can actually be scaled superlinearly if some conditions are met and very high noise robustness can be realized with very few coupled units. We discuss these conditions and show that this superlinear scalability depends on the nonlinearity of the individual dynamical units. The phenomenon is demonstrated in discrete as well as continuous dynamical systems. This superlinear scalability not only provides us an opportunity to exploit the nonlinearity of physical systems without being bogged down by noise but may also help us in understanding the functional role of coupled redundancy found in many biological systems. Moreover, engineers can exploit superlinear noise suppression by starting a coupled system near (not necessarily at) the appropriate initial condition.

  7. Nickel hydrogen battery expert system

    NASA Technical Reports Server (NTRS)

    Shiva, Sajjan G.

    1991-01-01

    The Hubble Telescope Battery Testbed at MSFC uses the Nickel Cadmium (NiCd) Battery Expert System (NICBES-2) which supports the evaluation of performance of Hubble Telescope spacecraft batteries and provides alarm diagnosis and action advice. NICBES-2 provides a reasoning system along with a battery domain knowledge base to achieve this battery health management function. An effort is summarized which was used to modify NICBES-2 to accommodate Nickel Hydrogen (NiH2) battery environment now in MSFC testbed. The NICBES-2 is implemented on a Sun Microsystem and is written in SunOS C and Quintus Prolog. The system now operates in a multitasking environment. NICBES-2 spawns three processes: serial port process (SPP); data handler process (DHP); and the expert system process (ESP) in order to process the telemetry data and provide the status and action advice. NICBES-2 performs orbit data gathering, data evaluation, alarm diagnosis and action advice and status and history display functions. The adaptation of NICBES-2 to work with NiH2 battery environment required modification to all of the three component processes.

  8. Intercommunications in Real Time, Redundant, Distributed Computer System

    NASA Technical Reports Server (NTRS)

    Zanger, H.

    1980-01-01

    An investigation into the applicability of fiber optic communication techniques to real time avionic control systems, in particular the total automatic flight control system used for the VSTOL aircraft is presented. The system consists of spatially distributed microprocessors. The overall control function is partitioned to yield a unidirectional data flow between the processing elements (PE). System reliability is enhanced by the use of triple redundancy. Some general overall system specifications are listed here to provide the necessary background for the requirements of the communications system.

  9. What Is An Expert System? ERIC Digest.

    ERIC Educational Resources Information Center

    Boss, Richard W.

    This digest describes and defines the various components of an expert system, e.g., a computerized tool designed to enhance the quality and availability of knowledge required by decision makers. It is noted that expert systems differ from conventional applications software in the following areas: (1) the existence of the expert systems shell, or…

  10. Expert systems applied to spacecraft fire safety

    NASA Technical Reports Server (NTRS)

    Smith, Richard L.; Kashiwagi, Takashi

    1989-01-01

    Expert systems are problem-solving programs that combine a knowledge base and a reasoning mechanism to simulate a human expert. The development of an expert system to manage fire safety in spacecraft, in particular the NASA Space Station Freedom, is difficult but clearly advantageous in the long-term. Some needs in low-gravity flammability characteristics, ventilating-flow effects, fire detection, fire extinguishment, and decision models, all necessary to establish the knowledge base for an expert system, are discussed.

  11. XPRT: An expert system shell

    SciTech Connect

    Cochrell, G.D.

    1988-09-01

    XPRT is a rule-based expert system shell written in the C programming language. This report contains a detailed description of the commands available in XPRT and also describes the syntax rules needed to construct a knowledge base. The shell's source code uses standard ANSI C, which allows it to run on any computer that can compile a C program. The executable code occupies 70K of PC memory. XPRT's inference engine can be commanded to backward chain or forward chain. Heuristics may be employed to reduce the search space of knowledge base rules. XPRT can read and write external files and spawn processes. The shell is mainly a symbolic processor but can handle numerical data as well. A mechanism of weighted facts and rules is used as an approach for handling uncertainty. XPRT is a no-frills shell with some very practical commands. The shell was used to write an expert system that is currently scheduling over a dozen software programs to maintain and manage a large departmental database. XPRT continues to evolve, and our organization is finding the shell to be a valuable programming tool. 6 refs.

  12. Risk management and expert system development methodology

    NASA Technical Reports Server (NTRS)

    Hull, Larry; Gilstrap, Lewey

    1991-01-01

    A risk-based expert-system development methodology has been developed to provide guidance to managers and technical personnel and to serve as a standard for developing expert systems. Expert-system development differs from conventional software development in that the information needed to prepare system requirements for expert systems is not known at the outset of a project and is obtained by knowledge engineering methods. The paper describes the expert-system life cycle, development methodology, and the approach taken in this methodology to manage and reduce the risks in expert system development. Also examined are the risks of using and of not using a methodology, the studies undertaken to validate the provisions of the expert system development methodology, and the results of these validation studies.

  13. Formalization and representation of expert systems

    SciTech Connect

    Tausner, M.R.

    1986-01-01

    Based on a critical analysis of the canonical forms of expert systems, definitions of classical forward-chaining production rule-based expert systems and classical backward-chaining production rule based expert systems are isolated as the fundamental basic definitions of an expert system. Two representation theorems are presented for the two fundamental types of expert systems defined. Both the classical forward-chaining production rule based expert systems and classical backward chaining production rule based expert systems are shown to be representable as type 3 languages (finite state automata). The pragmatic usefulness of the finite state representation of an expert system is established in the design of a multilevel expert system for general systems problems solving. A type 3 language is used to encapsulate the knowledge base and reasoning strategies of the front-end of the expert system, thus representing the front-end as a deterministic finite automation. This provides a new approach to the problem of interfacing multilevel expert systems.

  14. System and method for creating expert systems

    NASA Technical Reports Server (NTRS)

    Hughes, Peter M. (Inventor); Luczak, Edward C. (Inventor)

    1998-01-01

    A system and method provides for the creation of a highly graphical expert system without the need for programming in code. An expert system is created by initially building a data interface, defining appropriate Mission, User-Defined, Inferred, and externally-generated GenSAA (EGG) data variables whose data values will be updated and input into the expert system. Next, rules of the expert system are created by building appropriate conditions of the rules which must be satisfied and then by building appropriate actions of rules which are to be executed upon corresponding conditions being satisfied. Finally, an appropriate user interface is built which can be highly graphical in nature and which can include appropriate message display and/or modification of display characteristics of a graphical display object, to visually alert a user of the expert system of varying data values, upon conditions of a created rule being satisfied. The data interface building, rule building, and user interface building are done in an efficient manner and can be created without the need for programming in code.

  15. Method and system for redundancy management of distributed and recoverable digital control system

    NASA Technical Reports Server (NTRS)

    Stange, Kent (Inventor); Hess, Richard (Inventor); Kelley, Gerald B (Inventor); Rogers, Randy (Inventor)

    2012-01-01

    A method and system for redundancy management is provided for a distributed and recoverable digital control system. The method uses unique redundancy management techniques to achieve recovery and restoration of redundant elements to full operation in an asynchronous environment. The system includes a first computing unit comprising a pair of redundant computational lanes for generating redundant control commands. One or more internal monitors detect data errors in the control commands, and provide a recovery trigger to the first computing unit. A second redundant computing unit provides the same features as the first computing unit. A first actuator control unit is configured to provide blending and monitoring of the control commands from the first and second computing units, and to provide a recovery trigger to each of the first and second computing units. A second actuator control unit provides the same features as the first actuator control unit.

  16. Satellite operations support expert system

    NASA Technical Reports Server (NTRS)

    1985-01-01

    The Satellite Operations Support Expert System is an effort to identify aspects of satellite ground support activity which could profitably be automated with artificial intelligence (AI) and to develop a feasibility demonstration for the automation of one such area. The hydrazine propulsion subsystems (HPS) of the International Sun Earth Explorer (ISEE) and the International Ultraviolet Explorer (IUS) were used as applications domains. A demonstration fault handling system was built. The system was written in Franz Lisp and is currently hosted on a VAX 11/750-11/780 family machine. The system allows the user to select which HPS (either from ISEE or IUE) is used. Then the user chooses the fault desired for the run. The demonstration system generates telemetry corresponding to the particular fault. The completely separate fault handling module then uses this telemetry to determine what and where the fault is and how to work around it. Graphics are used to depict the structure of the HPS, and the telemetry values displayed on the screen are continually updated. The capabilities of this system and its development cycle are described.

  17. Liquid low level waste management expert system

    SciTech Connect

    Ferrada, J.J.; Abraham, T.J. ); Jackson, J.R. )

    1991-01-01

    An expert system has been developed as part of a new initiative for the Oak Ridge National Laboratory (ORNL) systems analysis program. This expert system will aid in prioritizing radioactive waste streams for treatment and disposal by evaluating the severity and treatability of the problem, as well as the final waste form. The objectives of the expert system development included: (1) collecting information on process treatment technologies for liquid low-level waste (LLLW) that can be incorporated in the knowledge base of the expert system, and (2) producing a prototype that suggests processes and disposal technologies for the ORNL LLLW system. 4 refs., 9 figs.

  18. Expert system technology for nondestructive waste assay

    SciTech Connect

    Becker, G.K.; Determan, J.C.

    1998-07-01

    Nondestructive assay waste characterization data generated for use in the National TRU Program must be of known and demonstrable quality. Each measurement is required to receive an independent technical review by a qualified expert. An expert system prototype has been developed to automate waste NDA data review of a passive/active neutron drum counter system. The expert system is designed to yield a confidence rating regarding measurement validity. Expert system rules are derived from data in a process involving data clustering, fuzzy logic, and genetic algorithms. Expert system performance is assessed against confidence assignments elicited from waste NDA domain experts. Performance levels varied for the active, passive shielded, and passive system assay modes of the drum counter system, ranging from 78% to 94% correct classifications.

  19. Analytical redundancy and the design of robust failure detection systems

    NASA Technical Reports Server (NTRS)

    Chow, E. Y.; Willsky, A. S.

    1984-01-01

    The Failure Detection and Identification (FDI) process is viewed as consisting of two stages: residual generation and decision making. It is argued that a robust FDI system can be achieved by designing a robust residual generation process. Analytical redundancy, the basis for residual generation, is characterized in terms of a parity space. Using the concept of parity relations, residuals can be generated in a number of ways and the design of a robust residual generation process can be formulated as a minimax optimization problem. An example is included to illustrate this design methodology. Previously announcedd in STAR as N83-20653

  20. Response-time optimization of rule-based expert systems

    NASA Astrophysics Data System (ADS)

    Zupan, Blaz; Cheng, Albert M. K.

    1994-03-01

    Real-time rule-based decision systems are embedded AI systems and must make critical decisions within stringent timing constraints. In the case where the response time of the rule- based system is not acceptable, it has to be optimized to meet both timing and integrity constraints. This paper describes a novel approach to reduce the response time of rule-based expert systems. Our optimization method is twofold: the first phase constructs the reduced cycle-free finite state transition system corresponding to the input rule-based system, and the second phase further refines the constructed transition system using the simulated annealing approach. The method makes use of rule-base system decomposition, concurrency, and state- equivalency. The new and optimized system is synthesized from the derived transition system. Compared with the original system, the synthesized system has fewer number of rule firings to reach the fixed point, is inherently stable, and has no redundant rules.

  1. An expert system for restructurable control

    NASA Technical Reports Server (NTRS)

    Litt, Jonathan

    1988-01-01

    Work in progress on an expert system which restructures and tunes control systems on-line is presented. The expert system coordinates the different methods for redesigning and implementing the control strategies due to system changes. The research is directed toward aircraft and jet engine applications. The implementation is written in LISP and is currently running on a special purpose LISP machine.

  2. Expert system modeling of a vision system

    NASA Astrophysics Data System (ADS)

    Reihani, Kamran; Thompson, Wiley E.

    1992-05-01

    The proposed artificial intelligence-based vision model incorporates natural recognition processes depicted as a visual pyramid and hierarchical representation of objects in the database. The visual pyramid, with based and apex representing pixels and image, respectively, is used as an analogy for a vision system. This paper provides an overview of recognition activities and states in the framework of an inductive model. Also, it presents a natural vision system and a counterpart expert system model that incorporates the described operations.

  3. Expert Systems: An Overview for Teacher-Librarians.

    ERIC Educational Resources Information Center

    Orwig, Gary; Barron, Ann

    1992-01-01

    Provides an overview of expert systems for teacher librarians. Highlights include artificial intelligence and expert systems; the development of the MYCIN medical expert system; rule-based expert systems; the use of expert system shells to develop a specific system; and how to select an appropriate application for an expert system. (11 references)…

  4. Toward the Development of Expert Assessment Systems.

    ERIC Educational Resources Information Center

    Hasselbring, Ted S.

    1986-01-01

    The potential application of "expert systems" to the diagnosis and assessment of special-needs children is examined and existing prototype systems are reviewed. The future of this artificial intelligence technology is discussed in relation to emerging development tools designed for the creation of expert systems by the lay public. (Author)

  5. Using Expert Systems For Computational Tasks

    NASA Technical Reports Server (NTRS)

    Duke, Eugene L.; Regenie, Victoria A.; Brazee, Marylouise; Brumbaugh, Randal W.

    1990-01-01

    Transformation technique enables inefficient expert systems to run in real time. Paper suggests use of knowledge compiler to transform knowledge base and inference mechanism of expert-system computer program into conventional computer program. Main benefit, faster execution and reduced processing demands. In avionic systems, transformation reduces need for special-purpose computers.

  6. Expert systems relations in space applications

    NASA Technical Reports Server (NTRS)

    Brady, Michael

    1987-01-01

    The problem of expert systems relations as they pertain to space applications is discussed. First, these systems are categorized and the relationships between them are analyzed. Then, the expert systems cooperation paradigm is proposed. This paradigm addresses various types of communication and coordination issues in an attempt to create a general model applicable in a number of situations.

  7. An Expert System for Environmental Data Management.

    ERIC Educational Resources Information Center

    Berka, Petr; Jirku, Petr

    1995-01-01

    Examines the possibility of using expert system tools for environmental data management. Describes the domain-independent expert system shell SAK and Knowledge EXplorer, a system that learns rules from data. Demonstrates the functionality of Knowledge EXplorer on an example of water quality evaluation. (LZ)

  8. Cooperative expert system reasoning for waste remediations

    SciTech Connect

    Bohn, S.J.; Pennock, K.A.; Franklin, A.L.

    1991-12-01

    The United States Department of Energy (DOE) is facing a large task in completing Remedial Investigations and Feasibility Studies (RI/FS) for hazardous waste sites across the nation. One of the primary objectives of an RI/FS is the specification of viable sequences of technology treatment trains which can provide implementable site solutions. We present a methodology which integrates expert system technology within an object-oriented framework to create a cooperative reasoning system designed to provide a comprehensive list of these implementable solutions. The system accomplishes its goal of specifying technology trains by utilizing a ``team`` of expert system objects. The system distributes the problem solving among the individual expert objects, and then coordinates the combination of individual decisions into a joint solution. Each expert object possesses the knowledge of an expert in a particular technology. An expert object can examine the parameters and characteristics of the waste site, seek information and support from other expert objects, and then make decisions concerning its own applicability. This methodology has at least two primary benefits. First, the creation of multiple expert objects provides a more direct mapping from the actual process to a software system, making the system easier to build. Second, the distribution of the inferencing among a number of loosely connected expert objects allows for a more robust and maintainable final product.

  9. Cooperative expert system reasoning for waste remediations

    SciTech Connect

    Bohn, S.J.; Pennock, K.A.; Franklin, A.L.

    1991-12-01

    The United States Department of Energy (DOE) is facing a large task in completing Remedial Investigations and Feasibility Studies (RI/FS) for hazardous waste sites across the nation. One of the primary objectives of an RI/FS is the specification of viable sequences of technology treatment trains which can provide implementable site solutions. We present a methodology which integrates expert system technology within an object-oriented framework to create a cooperative reasoning system designed to provide a comprehensive list of these implementable solutions. The system accomplishes its goal of specifying technology trains by utilizing a team'' of expert system objects. The system distributes the problem solving among the individual expert objects, and then coordinates the combination of individual decisions into a joint solution. Each expert object possesses the knowledge of an expert in a particular technology. An expert object can examine the parameters and characteristics of the waste site, seek information and support from other expert objects, and then make decisions concerning its own applicability. This methodology has at least two primary benefits. First, the creation of multiple expert objects provides a more direct mapping from the actual process to a software system, making the system easier to build. Second, the distribution of the inferencing among a number of loosely connected expert objects allows for a more robust and maintainable final product.

  10. Survivable algorithms and redundancy management in NASA's distributed computing systems

    NASA Technical Reports Server (NTRS)

    Malek, Miroslaw

    1992-01-01

    The design of survivable algorithms requires a solid foundation for executing them. While hardware techniques for fault-tolerant computing are relatively well understood, fault-tolerant operating systems, as well as fault-tolerant applications (survivable algorithms), are, by contrast, little understood, and much more work in this field is required. We outline some of our work that contributes to the foundation of ultrareliable operating systems and fault-tolerant algorithm design. We introduce our consensus-based framework for fault-tolerant system design. This is followed by a description of a hierarchical partitioning method for efficient consensus. A scheduler for redundancy management is introduced, and application-specific fault tolerance is described. We give an overview of our hybrid algorithm technique, which is an alternative to the formal approach given.

  11. CLIPS: An expert system building tool

    NASA Technical Reports Server (NTRS)

    Riley, Gary

    1991-01-01

    The C Language Integrated Production System (CLIPS) is an expert system building tool, which provides a complete environment for the development and delivery of rule and/or object based expert systems. CLIPS was specifically designed to provide a low cost option for developing and deploying expert system applications across a wide range of hardware platforms. The commercial potential of CLIPS is vast. Currently, CLIPS is being used by over 3,300 individuals throughout the public and private sector. Because the CLIPS source code is readily available, numerous groups have used CLIPS as a basis for their own expert system tools. To date, three commercially available tools have been derived from CLIPS. In general, the development of CLIPS has helped to improve the ability to deliver expert system technology throughout the public and private sectors for a wide range of applications and diverse computing environments.

  12. Expert system for analyzing eddy current measurements

    DOEpatents

    Levy, Arthur J.; Oppenlander, Jane E.; Brudnoy, David M.; Englund, James M.; Loomis, Kent C.

    1994-01-01

    A method and apparatus (called DODGER) analyzes eddy current data for heat exchanger tubes or any other metallic object. DODGER uses an expert system to analyze eddy current data by reasoning with uncertainty and pattern recognition. The expert system permits DODGER to analyze eddy current data intelligently, and obviate operator uncertainty by analyzing the data in a uniform and consistent manner.

  13. Expert system for analyzing eddy current measurements

    SciTech Connect

    Levy, A.J.; Oppenlander, J.E.; Brudnoy, D.M.; Englund, J.M.; Loomis, K.C.

    1994-08-16

    A method and apparatus (called DODGER) analyzes eddy current data for heat exchanger tubes or any other metallic object. DODGER uses an expert system to analyze eddy current data by reasoning with uncertainty and pattern recognition. The expert system permits DODGER to analyze eddy current data intelligently, and obviate operator uncertainty by analyzing the data in a uniform and consistent manner. 21 figs.

  14. Expert system for imaging spectrometer analysis results

    NASA Technical Reports Server (NTRS)

    Borchardt, Gary C.

    1985-01-01

    Information on an expert system for imaging spectrometer analysis results is outlined. Implementation requirements, the Simple Tool for Automated Reasoning (STAR) program that provides a software environment for the development and operation of rule-based expert systems, STAR data structures, and rule-based identification of surface materials are among the topics outlined.

  15. Computerized Adaptive Mastery Tests as Expert Systems.

    ERIC Educational Resources Information Center

    Frick, Theodore W.

    1992-01-01

    Discussion of expert systems and computerized adaptive tests describes two versions of EXSPRT, a new approach that combines uncertain inference in expert systems with sequential probability ratio test (SPRT) stopping rules. Results of two studies comparing EXSPRT to adaptive mastery testing based on item response theory and SPRT approaches are…

  16. Getting Started in Library Expert Systems Research.

    ERIC Educational Resources Information Center

    Borko, Harold

    1987-01-01

    Describes a microcomputer-based expert system, MAPPER, which is being developed to help catalog maps by employing the cognitive processes used by catalogers in applying Anglo American Cataloging Rules, 2nd edition (AACR2). The design process is reviewed, including the choice of a model expert system, MYCIN, and a software package, EXSYS.…

  17. Character complexity and redundancy in writing systems over human history

    PubMed Central

    Changizi, Mark A.; Shimojo, Shinsuke

    2005-01-01

    A writing system is a visual notation system wherein a repertoire of marks, or strokes, is used to build a repertoire of characters. Are there any commonalities across writing systems concerning the rules governing how strokes combine into characters; commonalities that might help us identify selection pressures on the development of written language? In an effort to answer this question we examined how strokes combine to make characters in more than 100 writing systems over human history, ranging from about 10 to 200 characters, and including numerals, abjads, abugidas, alphabets and syllabaries from five major taxa: Ancient Near-Eastern, European, Middle Eastern, South Asian, Southeast Asian. We discovered underlying similarities in two fundamental respects.The number of strokes per characters is approximately three, independent of the number of characters in the writing system; numeral systems are the exception, having on average only two strokes per character.Characters are ca. 50% redundant, independent of writing system size; intuitively, this means that a character’s identity can be determined even when half of its strokes are removed.Because writing systems are under selective pressure to have characters that are easy for the visual system to recognize and for the motor system to write, these fundamental commonalities may be a fingerprint of mechanisms underlying the visuo–motor system. PMID:15705551

  18. An adaptive technique for a redundant-sensor navigation system.

    NASA Technical Reports Server (NTRS)

    Chien, T.-T.

    1972-01-01

    An on-line adaptive technique is developed to provide a self-contained redundant-sensor navigation system with a capability to utilize its full potentiality in reliability and performance. This adaptive system is structured as a multistage stochastic process of detection, identification, and compensation. It is shown that the detection system can be effectively constructed on the basis of a design value, specified by mission requirements, of the unknown parameter in the actual system, and of a degradation mode in the form of a constant bias jump. A suboptimal detection system on the basis of Wald's sequential analysis is developed using the concept of information value and information feedback. The developed system is easily implemented, and demonstrates a performance remarkably close to that of the optimal nonlinear detection system. An invariant transformation is derived to eliminate the effect of nuisance parameters such that the ambiguous identification system can be reduced to a set of disjoint simple hypotheses tests. By application of a technique of decoupled bias estimation in the compensation system the adaptive system can be operated without any complicated reorganization.

  19. A prototype expert system for fishway design.

    PubMed

    Bender, M J; Katopodis, C; Simonovic, S P

    1992-12-01

    The design of structures for fish passage in rivers and streams provides an opportunity to apply expert system concepts to a design problem. Fishways contribute to the sustainable development of water resources projects by providing a path that allows fish migrations to be maintained. A prototype expert system (FDES) has been developed to recommend the most suitable fishway type for given design conditions. A recommendation is provided on the basis of fishway hydraulics, fish passage performance, and cost requirements. Fishway design demands expertise in various scientific disciplines such as hydrology, hydraulics, and fish biology. Expert system technology may be used to reduce design time requirements and to serve as a teaching aid to inexperienced engineers by organizing and accessing the cumulative knowledge of the most experienced designers. The rule-based expert system development tool, VP-Expert, supplies the backward chaining control structure for accessing the knowledge within the prototype. PMID:24227094

  20. DISPO Advisor: Expert System for Psychiatric Disposition

    PubMed Central

    Barta, Patrick; Barta, Wendy

    1988-01-01

    An expert system was designed to assist psychiatric residents at the Johns Hopkins Hospital. This microcomputer based decision support system helps residents find the proper disposition for patients who come to the emergency room. The system uses an inexpensive, commercially available expert system shell, VP-EXPERT by Paperback Software, to match patients with inpatient and outpatient resources appropriate to their needs. The inference engine uses both forward and backward chaining, and interfaces with data stored in DBase III files. The system is currently in daily use by residents.

  1. Redundant uplink optical channel for visible light communication systems

    NASA Astrophysics Data System (ADS)

    Vladescu, Marian; Vuza, Dan Tudor

    2015-02-01

    The increased interest in optical wireless (OW), as a complementary solution for radio frequency (RF) wireless technology, in conjunction with the significant deployments in LED lighting technology, led to the need to achieve lighting and wireless communication simultaneously in indoor environments. Visible light communication (VLC) technology provides an opportunity and infrastructure for the high-speed low-cost wireless communication. There are still open issues in VLC such as: uplink channel, LED modulation bandwidth, and LED nonlinearity. In this paper we addressed the uplink channel implementation, being a key issue in the OW communication system in order to allow full connectivity for a terminal (duplex transmission). VLC in full duplex mode requires the usage of a hybrid technology, such as infrared optical uplink, retro-reflecting transceivers, or even RF. The solution we proposed is to create a redundant optical uplink channel, using near ultraviolet (UV) and near infrared (IR) spectra.

  2. How a system backfires: dynamics of redundancy problems in security.

    PubMed

    Ghaffarzadegan, Navid

    2008-12-01

    Increasing attention is being paid to reliability, safety, and security issues in social systems. Scott Sagan examined why more security forces (a redundancy solution) may lead to less security. He discussed how such a solution can backfire due to three major issues (i.e., "common-mode error,"social shirking," and "overcompensation"). In this article, using Sagan's hypotheses, we simulate and analyze a simple and generic security system as more guards are added to the system. Simulation results support two of Sagan's hypotheses. More specifically, the results show that "common-mode error" causes the system to backfire, and "social shirking" leads to an inefficient system while exacerbating the common-mode error's effect. Simulation results show that "overcompensation" has no effect of backfiring, but it leads the system to a critical state in which it can easily be affected by the common-mode error. Furthermore, the simulation results make us question the importance of the initial power of adversaries (e.g., terrorists) as the results show that, for any exogenous level of adversary power, the system endogenously overcompensates to a level that makes the system more susceptible to being attacked. PMID:18826416

  3. NESSUS/EXPERT - An expert system for probabilistic structural analysis methods

    NASA Technical Reports Server (NTRS)

    Millwater, H.; Palmer, K.; Fink, P.

    1988-01-01

    An expert system (NESSUS/EXPERT) is presented which provides assistance in using probabilistic structural analysis methods. NESSUS/EXPERT is an interactive menu-driven expert system that provides information to assist in the use of the probabilistic finite element code NESSUS/FEM and the fast probability integrator. NESSUS/EXPERT was developed with a combination of FORTRAN and CLIPS, a C language expert system tool, to exploit the strengths of each language.

  4. Multiple strategies of reasoning for expert systems

    SciTech Connect

    Yao Yuchuan; Kulikowski, C.A.

    1983-01-01

    In expert systems the heuristics used for combining the weight of evidence can be based on probabilistic, fuzzy set, or subjective confidence factors. Although the underlying assumptions for each of the methods differ, it can be shown that there are correspondences between them and that it is possible to develop a model of expert reasoning for medical consultation using any one of the methods. The authors have developed a system for representing expert knowledge, called ESMES, which is an outgrowth of the expert scheme developed earlier at Rutgers. ESMES allows the use of alternative strategies in the solution of a consultation problem. The authors report on the performance of ESMES for a prototype glaucoma consultation model, using reasoning mechanisms similar to those of the expert, MYCIN, Internist I, and Prospector systems. 9 references.

  5. Uncertainty reasoning in expert systems

    NASA Technical Reports Server (NTRS)

    Kreinovich, Vladik

    1993-01-01

    Intelligent control is a very successful way to transform the expert's knowledge of the type 'if the velocity is big and the distance from the object is small, hit the brakes and decelerate as fast as possible' into an actual control. To apply this transformation, one must choose appropriate methods for reasoning with uncertainty, i.e., one must: (1) choose the representation for words like 'small', 'big'; (2) choose operations corresponding to 'and' and 'or'; (3) choose a method that transforms the resulting uncertain control recommendations into a precise control strategy. The wrong choice can drastically affect the quality of the resulting control, so the problem of choosing the right procedure is very important. From a mathematical viewpoint these choice problems correspond to non-linear optimization and are therefore extremely difficult. In this project, a new mathematical formalism (based on group theory) is developed that allows us to solve the problem of optimal choice and thus: (1) explain why the existing choices are really the best (in some situations); (2) explain a rather mysterious fact that fuzzy control (i.e., control based on the experts' knowledge) is often better than the control by these same experts; and (3) give choice recommendations for the cases when traditional choices do not work.

  6. Expert systems for Space Station automation

    NASA Technical Reports Server (NTRS)

    Georgeff, M. P.; Firschein, O.

    1985-01-01

    The expert systems required for automating key functions of the Manned Space Station (MSS) are explored. It is necessary that the expert systems developed be flexible, degrade gracefully in the case of a failure, and be able to work with incomplete data. The AI systems will have to perform interpretation and diagnosis, design, prediction and induction, and monitoring and control functions. Both quantitative and qualitative reasoning capabilities need improvements, as do automatic verification techniques, explanation and learning capabilities, and the use of metaknowledge, i. e., knowledge about the knowledge contained in the knowledge base. Information retrieval, fault isolation and manufacturing process control demonstrations are needed to validate expert systems for the MSS.

  7. Communications and tracking expert systems study

    NASA Technical Reports Server (NTRS)

    Leibfried, T. F.; Feagin, Terry; Overland, David

    1987-01-01

    The original objectives of the study consisted of five broad areas of investigation: criteria and issues for explanation of communication and tracking system anomaly detection, isolation, and recovery; data storage simplification issues for fault detection expert systems; data selection procedures for decision tree pruning and optimization to enhance the abstraction of pertinent information for clear explanation; criteria for establishing levels of explanation suited to needs; and analysis of expert system interaction and modularization. Progress was made in all areas, but to a lesser extent in the criteria for establishing levels of explanation suited to needs. Among the types of expert systems studied were those related to anomaly or fault detection, isolation, and recovery.

  8. An overview of expert systems. [artificial intelligence

    NASA Technical Reports Server (NTRS)

    Gevarter, W. B.

    1982-01-01

    An expert system is defined and its basic structure is discussed. The knowledge base, the inference engine, and uses of expert systems are discussed. Architecture is considered, including choice of solution direction, reasoning in the presence of uncertainty, searching small and large search spaces, handling large search spaces by transforming them and by developing alternative or additional spaces, and dealing with time. Existing expert systems are reviewed. Tools for building such systems, construction, and knowledge acquisition and learning are discussed. Centers of research and funding sources are listed. The state-of-the-art, current problems, required research, and future trends are summarized.

  9. Expert system to design communications circuits

    SciTech Connect

    Tolendino, L.F.; Vahle, M.O.

    1986-07-01

    An expert system has been created to aid the design of fiber optic based communications circuits. The design system is based on an Apollo workstation, LISP and CPSL, an in-house developed expert system language. The optical circuit is taken from design specification through hardware selection and circuit routing to the production of detailed schematics and routing guides. A database containing the entire fiber optic trunk system is also maintained.

  10. Multi-finger prehension: control of a redundant mechanical system.

    PubMed

    Latash, Mark L; Zatsiorsky, Vladimir M

    2009-01-01

    The human hand has been a fascinating object of study for researchers in both biomechanics and motor control. Studies of human prehension have contributed significantly to the progress in addressing the famous problem of motor redundancy. After a brief review of the hand mechanics, we present results of recent studies that support a general view that the apparently redundant design of the hand is not a source of computational problems but a rich apparatus that allows performing a variety of tasks in a reliable and flexible way (the principle of abundance). Multi-digit synergies have been analyzed at two levels of a hypothetical hierarchy involved in the control of prehensile actions. At the upper level, forces and moments produced by the thumb and virtual finger (an imagined finger with a mechanical action equal to the combined mechanical action of all four fingers of the hand) co-vary to stabilize the gripping action and the orientation of the hand-held object. These results support the principle of superposition suggested earlier in robotics with respect to the control of artificial grippers. At the lower level of the hierarchy, forces and moments produced by individual fingers co-vary to stabilize the magnitude and direction of the force vector and the moment of force produced by the virtual finger. Adjustments to changes in task constraints (such as, for example, friction under individual digits) may be local and synergic. The latter reflect multi-digit prehension synergies and may be analyzed with the so-called chain effects: Sequences of relatively straightforward cause-effect links directly related to mechanical constraints leading to non-trivial strong co-variation between pairs of elemental variables. Analysis of grip force adjustments during motion of hand-held objects suggests that the central nervous system adjusts to gravitational and inertial loads differently. The human hand is a gold mine for researchers interested in the control of natural human

  11. Validation and verification of expert systems

    NASA Technical Reports Server (NTRS)

    Gilstrap, Lewey

    1991-01-01

    Validation and verification (V&V) are procedures used to evaluate system structure or behavior with respect to a set of requirements. Although expert systems are often developed as a series of prototypes without requirements, it is not possible to perform V&V on any system for which requirements have not been prepared. In addition, there are special problems associated with the evaluation of expert systems that do not arise in the evaluation of conventional systems, such as verification of the completeness and accuracy of the knowledge base. The criticality of most NASA missions make it important to be able to certify the performance of the expert systems used to support these mission. Recommendations for the most appropriate method for integrating V&V into the Expert System Development Methodology (ESDM) and suggestions for the most suitable approaches for each stage of ESDM development are presented.

  12. EMMA: The expert system for munition maintenance

    NASA Technical Reports Server (NTRS)

    Mullins, Barry E.

    1988-01-01

    Expert Missile Maintenance Aid (EMMA) is a first attempt to enhance maintenance of the tactical munition at the field and depot level by using artificial intelligence (AI) techniques. The ultimate goal of EMMA is to help a novice maintenance technician isolate and diagnose electronic, electromechanical, and mechanical equipment faults to the board/chassis level more quickly and consistently than the best human expert using the best currently available automatic test equipment (ATE). To this end, EMMA augments existing ATE with an expert system that captures the knowledge of design and maintenance experts. The EMMA program is described, including the evaluation of field-level expert system prototypes, the description of several study tasks performed during EMMA, and future plans for a follow-on program. This paper will briefly address several study tasks performed during EMMA. The paper concludes with a discussion of future plans for a follow-on program and other areas of concern.

  13. Towards reasoning visualization in expert systems

    NASA Technical Reports Server (NTRS)

    Selig, William John; Johannes, James D.

    1989-01-01

    Preliminary results are presented of ongoing research to develop visualization paradigms for expert systems reasoning processes. The results are based in part on a prototype implementation that is being developed to visualize the reasoning processes of a rule-based forward chaining expert system. The research is based on the premise that the presentation of information at the highest applicable conceptual level will enhance the assimilation of that information. Hierarchical levels in both the syntactic and semantic levels of reasoning in expert systems are described in detail.

  14. Executive system software design and expert system implementation

    NASA Technical Reports Server (NTRS)

    Allen, Cheryl L.

    1992-01-01

    The topics are presented in viewgraph form and include: software requirements; design layout of the automated assembly system; menu display for automated composite command; expert system features; complete robot arm state diagram and logic; and expert system benefits.

  15. ZEX: An expert system for ZEUS

    NASA Astrophysics Data System (ADS)

    Behrens, U.; Flasinski, M.; Hagge, L.; Ohrenberg, K.

    1994-02-01

    ZEX is an expert system which is designed to support operation of ZEUS experiment. It is based on performance monitoring and offers diagnostic capabilities and instructions on how to proceed running the experiment. System architecture and implementation methods are discussed. A prototype version of the expert system, ZEX-P, has been implemented successfully and has been operating since the beginning of 1993. Experience gained in the design and implementation of ZEX-P and first results are reported.

  16. Expert System Enhanced Work Station for Dentists*

    PubMed Central

    Truax, Terry D.; Bailit, Howard L.

    1987-01-01

    A microcomputer based workstation has been created to provide the clinical dentist with an expert system enhanced, voice driven, IBM PC based program to support both the clinical and financial functions of a small dental practice. The data management system is complete and undergoing clinical tests. An initial expert system with knowledge bases for two clinical problems has been developed. Additional clinical and financial knowledge bases are under development.

  17. Jess, the Java expert system shell

    SciTech Connect

    Friedman-Hill, E.J.

    1997-11-01

    This report describes Jess, a clone of the popular CLIPS expert system shell written entirely in Java. Jess supports the development of rule-based expert systems which can be tightly coupled to code written in the powerful, portable Java language. The syntax of the Jess language is discussed, and a comprehensive list of supported functions is presented. A guide to extending Jess by writing Java code is also included.

  18. Restoring Redundancy to the Wilkinson Microwave Anisotrophy Probe Propulsion System

    NASA Technical Reports Server (NTRS)

    O'Donnell, James R., Jr.; Davis, Gary T.; Ward, David K.

    2004-01-01

    The Wilkinson Microwave Anisotropy Probe is a follow-on to the Differential Microwave Radiometer instrument on the Cosmic Background Explorer. Attitude control system engineers discovered sixteen months before launch that configuration changes after the critical design review had resulted in a significant migration of the spacecraft's center of mass. As a result, the spacecraft no longer had a viable backup control mode in the event of a failure of the negative pitch-axis thruster. A tiger team was formed and identified potential solutions to this problem, such as adding thruster-plume shields to redirect thruster torque, adding or removing mass from the spacecraft, adding an additional thruster, moving thrusters, bending thruster nozzles or propellant tubing, or accepting the loss of redundancy. The project considered the impacts on mass, cost, fuel budget, and schedule for each solution, and decided to bend the propellant tubing of the two roll-control thrusters to allow the pair to be used for backup control in the negative pitch axis. This paper discusses the problem and the potential solutions, and documents the hardware and software changes and verification performed. Flight data are presented to show the on-orbit performance of the propulsion system and lessons learned are described.

  19. System Experts and Decision Making Experts in Transdisciplinary Projects

    ERIC Educational Resources Information Center

    Mieg, Harald A.

    2006-01-01

    Purpose: This paper aims at a better understanding of expert roles in transdisciplinary projects. Thus, the main purpose is the analysis of the roles of experts in transdisciplinary projects. Design/methodology/approach: The analysis of the ETH-UNS case studies from the point of view of the psychology of expertise and the sociology of professions…

  20. Developing an Expert System for Nursing Practice

    PubMed Central

    Ozbolt, Judy G.; Schultz, Samuel; Swain, Mary Ann P.; Abraham, Ivo L.; Farchaus-Stein, Karen

    1984-01-01

    The American Nurses' Association has set eight Standards of Nursing Practice related to the nursing process. Computer-aided information systems intended to facilitate the nursing process must be designed to promote adherence to these professional standards. For each of the eight standards, the paper tells how a hypothetical expert system could help nurses to meet the standard. A prototype of such an expert system is being developed. The paper describes issues in conceptualizing clinical decision-making and developing decision strategies for the prototype system. The process of developing the prototype system is described.

  1. Expert system prototype of food aid distribution.

    PubMed

    Singh, Neeta

    2007-01-01

    The aim of this study was to improve efficiency of the food aid distribution process of international food relief organizations. An overall objective of this study was to develop a prototype expert system for monitoring and evaluating food aid by international disaster relief organizations. The research identifies data related to monitoring and evaluation processes of various international food-aid organizations. It then applies an artificial intelligence-based expert system to develop a prototype for those processes. Existing data related to monitoring and evaluation program cycles were obtained. An expert system shell called CLIPS(c) (National Aeronautics Space Administration) was used to develop a prototype system named Food Aid Monitor, a rule-based expert system, which uses facts and heuristic rules to provide an adaptive feedback regarding monitoring and evaluating processes at various stages of food aid operation. The Food Aid Monitor was evaluated and validated by three expert panels checking the prototype system for completeness, relevancy, consistency, correctness, precision, and use-ability. Finally, the panels indicated a belief that the system could have an overall positive impact on the stages of monitoring and evaluating food aid processes of the food relief organizations. PMID:17392088

  2. Rocket engine control and monitoring expert system

    NASA Technical Reports Server (NTRS)

    Ali, Moonis; Crawford, Roger

    1988-01-01

    This paper focuses on the application of expert systems technology to the automatic detection, verification and correction of anomalous rocket engine operations through interfacing with an intelligent adaptive control system. The design of a reliable and intelligent propulsion control and monitoring system is outlined which includes the architecture of an Integrated Expert System (IES) serving as the core component. The IES functions include automatic knowledge acquisition, integrated knowledge base, and fault diagnosis and prediction methodology. The results of fault analysis and diagnostic techniques are presented for an example fault in the SSME main combustion chamber injectors.

  3. Expert system for scheduling simulation lab sessions

    NASA Technical Reports Server (NTRS)

    Lund, Chet

    1990-01-01

    Implementation and results of an expert system used for scheduling session requests for the Systems Engineering Simulator (SES) laboratory at the NASA Johnson Space Center (JSC) are discussed. Weekly session requests are received from astronaut crew trainers, procedures developers, engineering assessment personnel, software developers, and various others who wish to access the computers, scene generators, and other simulation equipment available to them in the SES lab. The expert system under discussion is comprised of a data acquisition portion - two Pascal programs run on a personal computer - and a CLIPS program installed on a minicomputer. A brief introduction to the SES lab and its scheduling background is given. A general overview of the system is provided, followed by a detailed description of the constraint-reduction process and of the scheduler itself. Results from a ten-week trial period using this approach are discussed. Finally, a summary of the expert system's strengths and shortcomings are provided.

  4. The diagnosis of microcytic anemia by a rule-based expert system using VP-Expert.

    PubMed

    O'Connor, M L; McKinney, T

    1989-09-01

    We describe our experience in creating a rule-based expert system for the interpretation of microcytic anemia using the expert system development tool, VP-Expert, running on an IBM personal computer. VP-Expert processes data (complete blood cell count results, age, and sex) according to a set of user-written logic rules (our program) to reach conclusions as to the following causes of microcytic anemia: alpha- and beta-thalassemia trait, iron deficiency, and anemia of chronic disease. Our expert system was tested using previously interpreted complete blood cell count data. In most instances, there was good agreement between the expert system and its pathologist-author, but many discrepancies were found in the interpretation of anemia of chronic disease. We conclude that VP-Expert has a useful level of power and flexibility, yet is simple enough that individuals with modest programming experience can create their own expert systems. Limitations of such expert systems are discussed. PMID:2774865

  5. [Utilization of expert systems in psychiatry].

    PubMed

    Ohayon, M M

    1993-04-01

    Are expert systems liable to be used as consultants in psychiatry? Most expert systems deal with an over-restricted part of psychiatry and cannot be a real help in everyday care. Moreover, most of them are not actually validated (the comparison between the system's and the expert's conclusions in a few cases is not enough). Another problem is that they reflect the uncertainties of nosographic problems. Validation of such systems needs the careful checking of the logical structure of the underlying nosography, the fitness of the structure's knowledge base and the fitness of the inference engine. Moreover, the naïve use of the system by untrained clinicians is the best means of validation since it provides real life proof of the ability of expert systems to make diagnoses in unselected cases where the need for a common diagnostic reference is clear (for example, epidemiologic, psychopharmacological ornosographic research). Some of the best known expert systems in the field of psychiatry are reviewed and another expert system, Adinfer, is presented. Developed since 1982, Adinfer is a forward-tracking level O system (in its simplified version for micro-computers). The knowledge base is a translation of the DSM-III-R into production rules. The program has been included in several software packages and used in many clinical studies, both among psychiatrists and physicians. The program has been validated with 1,141 unselected cases, and with 47 physicians: an 83% agreement rate was found between the system's and the physician's diagnoses, taking into account that the clinicians were asked to give their conclusions according to their usual nosography.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8500073

  6. Commercial Expert-System-Building Software Tools

    NASA Technical Reports Server (NTRS)

    Gevarter, William B.

    1989-01-01

    Report evaluates commercially-available expert-system-building tools in terms of structures, representations of knowledge, inference mechanisms, interfaces with developers and end users, and capabilities of performing such functions as diagnosis and design. Software tools commercialized derivatives of artificial-intelligence systems developed by researchers at universities and research organizations. Reducing time to develop expert system by order of magnitude compared to that required with such traditional artificial development languages as LISP. Table lists 20 such tools, rating attributes as strong, fair, programmable by user, or having no capability in various criteria.

  7. Ethernet redundancy

    SciTech Connect

    Burak, K.

    2006-07-01

    We describe the Ethernet systems and their evolution: LAN Segmentation, DUAL networks, network loops, network redundancy and redundant network access. Ethernet (IEEE 802.3) is an open standard with no licensing fees and its specifications are freely available. As a result, it is the most popular data link protocol in use. It is important that the network be redundant and standard Ethernet protocols like RSTP (IEEE 802.1w) provide the fast network fault detection and recovery times that is required today. As Ethernet does continue to evolve, network redundancy is and will be a mixture of technology standards. So it is very important that both end-stations and networking devices be Ethernet (IEEE 802.3) compliant. Then when new technologies, such as the IEEE 802.1aq Shortest Path Bridging protocol, come to market they can be easily deployed in the network without worry.

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

    NASA Technical Reports Server (NTRS)

    1981-01-01

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

  9. Study of techniques for redundancy verification without disrupting systems, phases 1-3

    NASA Technical Reports Server (NTRS)

    1970-01-01

    The problem of verifying the operational integrity of redundant equipment and the impact of a requirement for verification on such equipment are considered. Redundant circuits are examined and the characteristics which determine adaptability to verification are identified. Mutually exclusive and exhaustive categories for verification approaches are established. The range of applicability of these techniques is defined in terms of signal characteristics and redundancy features. Verification approaches are discussed and a methodology for the design of redundancy verification is developed. A case study is presented which involves the design of a verification system for a hypothetical communications system. Design criteria for redundant equipment are presented. Recommendations for the development of technological areas pertinent to the goal of increased verification capabilities are given.

  10. An expert system for window glazing design

    SciTech Connect

    Foss, R.V. ); Droste, D.H.

    1990-01-01

    An integrated expert system was developed to facilitate the design of window glass for structural strength, hydrostatic loads, sound attenuation, and solar control. The integrated software consists of a text-based interface, a rule-based expert system, and two neural networks. The text of a glazing design guide is linked by related topics and concepts. The software's design feature lets the user enter design parameters for the window choice via an interactive consultation in to a rule-based expert system that critiques the design. The technical aspects of the glass's structural strength are based primarily on linear methods published by the American Architectural Manufacturers Association Statistical correlations for the new nonlinear failure prediction for glass strength are used to automatically design for the minimum glass thickness required to withstand a specified load. Neural networks estimate values for sound attenuation and solar transmission characteristics from laboratory test data on selected glass constructions.

  11. A Generic Expert Scheduling System Architecture and Toolkit: GUESS (Generically Used Expert Scheduling System)

    NASA Technical Reports Server (NTRS)

    Liebowitz, Jay; Krishnamurthy, Vijaya; Rodens, Ira; Houston, Chapman; Liebowitz, Alisa; Baek, Seung; Radko, Joe; Zeide, Janet

    1996-01-01

    Scheduling has become an increasingly important element in today's society and workplace. Within the NASA environment, scheduling is one of the most frequently performed and challenging functions. Towards meeting NASA's scheduling needs, a research version of a generic expert scheduling system architecture and toolkit has been developed. This final report describes the development and testing of GUESS (Generically Used Expert Scheduling System).

  12. Reliability analysis of redundant systems. [a method to compute transition probabilities

    NASA Technical Reports Server (NTRS)

    Yeh, H. Y.

    1974-01-01

    A method is proposed to compute the transition probability (the probability of partial or total failure) of parallel redundant system. The effect of geometry of the system, the direction of load, and the degree of redundancy on the probability of complete survival of parachute-like system are also studied. The results show that the probability of complete survival of three-member parachute-like system is very sensitive to the variation of horizontal angle of the load. However, it becomes very insignificant as the degree of redundancy increases.

  13. Visual Cues for an Adaptive Expert System.

    ERIC Educational Resources Information Center

    Miller, Helen B.

    NCR (National Cash Register) Corporation is pursuing opportunities to make their point of sale (POS) terminals easy to use and easy to learn. To approach the goal of making the technology invisible to the user, NCR has developed an adaptive expert prototype system for a department store POS operation. The structure for the adaptive system, the…

  14. Estrogen receptor expert system overview and examples

    EPA Science Inventory

    The estrogen receptor expert system (ERES) is a rule-based system developed to prioritize chemicals based upon their potential for binding to the ER. The ERES was initially developed to predict ER affinity of chemicals from two specific EPA chemical inventories, antimicrobial pe...

  15. Artificial Intelligence and Expert Systems.

    ERIC Educational Resources Information Center

    Lawlor, Joseph

    Artificial intelligence (AI) is the field of scientific inquiry concerned with designing machine systems that can simulate human mental processes. The field draws upon theoretical constructs from a wide variety of disciplines, including mathematics, psychology, linguistics, neurophysiology, computer science, and electronic engineering. Some of the…

  16. Space Shuttle Avionics: a Redundant IMU On-Board Checkout and Redundancy Management System

    NASA Technical Reports Server (NTRS)

    Mckern, R. A.; Brown, D. G.; Dove, D. W.; Gilmore, J. P.; Landey, M. E.; Musoff, H.; Amand, J. S.; Vincent, K. T., Jr.

    1972-01-01

    A failure detection and isolation philosophy applicable to multiple off-the-shelf gimbaled IMUs are discussed. The equations developed are implemented and evaluated with actual shuttle trajectory simulations. The results of these simulations are presented for both powered and unpowered flight phases and at operational levels of four, three, and two IMUs. A multiple system checkout philosophy is developed and simulation results presented. The final task develops a laboratory test plan and defines the hardware and software requirements to implement an actual multiple system and evaluate the interim study results for space shuttle application.

  17. Expert system terms and building tools

    NASA Technical Reports Server (NTRS)

    Gevarter, William B.

    1988-01-01

    The characteristics of an Expert System Building Tool (ESBT) capable of inference and hypothetical reasoning are discussed. The inference capabilities of ESBTs allow such functions as classification, design-synthesis, forecasting, decision-aiding, scheduling and planning, real-time monitoring, situation assessment, the discovery of novel relations, and debugging. ESBTs are noted to have made possible order-of-magnitude improvements in expert system construction. Higher-end ESBTs are moving from LISP machines to less expensive workstations, and lower-end ones are appearing on PCs.

  18. Spacecraft command and control using expert systems

    NASA Technical Reports Server (NTRS)

    Norcross, Scott; Grieser, William H.

    1994-01-01

    This paper describes a product called the Intelligent Mission Toolkit (IMT), which was created to meet the changing demands of the spacecraft command and control market. IMT is a command and control system built upon an expert system. Its primary functions are to send commands to the spacecraft and process telemetry data received from the spacecraft. It also controls the ground equipment used to support the system, such as encryption gear, and telemetry front-end equipment. Add-on modules allow IMT to control antennas and antenna interface equipment. The design philosophy for IMT is to utilize available commercial products wherever possible. IMT utilizes Gensym's G2 Real-time Expert System as the core of the system. G2 is responsible for overall system control, spacecraft commanding control, and spacecraft telemetry analysis and display. Other commercial products incorporated into IMT include the SYBASE relational database management system and Loral Test and Integration Systems' System 500 for telemetry front-end processing.

  19. Application of redundancy in the Saturn 5 guidance and control system

    NASA Technical Reports Server (NTRS)

    Moore, F. B.; White, J. B.

    1976-01-01

    The Saturn launch vehicle's guidance and control system is so complex that the reliability of a simplex system is not adequate to fulfill mission requirements. Thus, to achieve the desired reliability, redundancy encompassing a wide range of types and levels was employed. At one extreme, the lowest level, basic components (resistors, capacitors, relays, etc.) are employed in series, parallel, or quadruplex arrangements to insure continued system operation in the presence of possible failure conditions. At the other extreme, the highest level, complete subsystem duplication is provided so that a backup subsystem can be employed in case the primary system malfunctions. In between these two extremes, many other redundancy schemes and techniques are employed at various levels. Basic redundancy concepts are covered to gain insight into the advantages obtained with various techniques. Points and methods of application of these techniques are included. The theoretical gain in reliability resulting from redundancy is assessed and compared to a simplex system. Problems and limitations encountered in the practical application of redundancy are discussed as well as techniques verifying proper operation of the redundant channels. As background for the redundancy application discussion, a basic description of the guidance and control system is included.

  20. Fuzzy expert system shell for scheduling

    NASA Astrophysics Data System (ADS)

    Turksen, I. B.; Yurtsever, Tanju; Demirli, K.

    1993-12-01

    The Fuzzy Logic Expert System Scheduler (FLES) is a unique, on-line, interactive shop floor scheduler that is designed to produce detailed, realistic schedules for day-to-day production management. The user can exercise the control of FLES to produce scheduling assignments over short or long term scheduling horizons or to simulate different plant capacity conditions to analyze their effect on future work plans. The unique and proprietary feature of FLES is its `Decision Engine', a fuzzy knowledge base system that models the reasoning process of a human expert is used to give job releasing and job dispatching decisions. Expert knowledge in terms of fuzzy production rules represented by the use of linguistic variables. The values of these linguistic variables are defined by context dependent fuzzy sets whose meanings are specified by graded membership functions.

  1. Expert systems should be more accurate than human experts - Evaluation procedures from human judgment and decisionmaking

    NASA Technical Reports Server (NTRS)

    Levi, Keith

    1989-01-01

    Two procedures for the evaluation of the performance of expert systems are illustrated: one procedure evaluates predictive accuracy; the other procedure is complementary in that it uncovers the factors that contribute to predictive accuracy. Using these procedures, it is argued that expert systems should be more accurate than human experts in two senses. One sense is that expert systems must be more accurate to be cost-effective. Previous research is reviewed and original results are presented which show that simple statistical models typically perform better than human experts for the task of combining evidence from a given set of information sources. The results also suggest the second sense in which expert systems should be more accurate than human experts. They reveal that expert systems should share factors that contribute to human accuracy, but not factors that detract from human accuracy. Thus the thesis is that one should both require and expect systems to be more accurate than humans.

  2. Expert system for transuranic waste assay

    SciTech Connect

    Zoolalian, M.L.; Gibbs, A.; Kuhns, J.D.

    1989-01-01

    Transuranic wastes are generated at the Savannah River Site (SRS) as a result of routine production of nuclear materials. These wastes contain Pu-238 and Pu-239 and are placed into lined 55-gallon waste drums. The drums are placed on monitored storage pads pending shipment to the Waste Isolation Pilot Plant in New Mexico. A passive-active neutron (PAN) assay system is used to determine the mass of the radioactive material within the waste drums. Assay results are used to classify the wastes as either low-level or transuranic (TRU). During assays, the PAN assay system communicates with an IBM-AT computer. A Fortran computer program, called NEUT, controls and performs all data analyses. Unassisted, the NEUT program cannot adequately interpret assay results. To eliminate this limitation, an expert system shell was used to write a new algorithm, called the Transuranic Expert System (TRUX), to drive the NEUT program and add decision making capabilities for analysis of the assay results. The TRUX knowledge base was formulated by consulting with human experts in the field of neutron assay, by direct experimentation on the PAN assay system, and by observing operations on a daily basis. TRUX, with its improved ability to interpret assay results, has eliminated the need for close supervision by a human expert, allowing skilled technicians to operate the PAN assay system. 4 refs., 1 fig., 4 tabs.

  3. Design and test experience with a triply redundant digital fly-by-wire control system

    NASA Technical Reports Server (NTRS)

    Szalai, K. J.; Felleman, P. G.; Gera, J.; Glover, R. D.

    1976-01-01

    A triplex digital fly-by-wire flight control system was developed and then installed in a NASA F-8C aircraft to provide fail-operative, full authority control. Hardware and software redundancy management techniques were designed to detect and identify failures in the system. Control functions typical of those projected for future actively controlled vehicles were implemented. This paper describes the principal design features of the system, the implementation of computer, sensor, and actuator redundancy management, and the ground test results. An automated test program to verify sensor redundancy management software is also described.

  4. Knowledge-Acquisition Tool For Expert System

    NASA Technical Reports Server (NTRS)

    Disbrow, James D.; Duke, Eugene L.; Regenie, Victoria A.

    1988-01-01

    Digital flight-control systems monitored by computer program that evaluates and recommends. Flight-systems engineers for advanced, high-performance aircraft use knowlege-acquisition tool for expert-system flight-status monitor suppling interpretative data. Interpretative function especially important in time-critical, high-stress situations because it facilitates problem identification and corrective strategy. Conditions evaluated and recommendations made by ground-based engineers having essential knowledge for analysis and monitoring of performances of advanced aircraft systems.

  5. The Elements Of Adaptive Neural Expert Systems

    NASA Astrophysics Data System (ADS)

    Healy, Michael J.

    1989-03-01

    The generalization properties of a class of neural architectures can be modelled mathematically. The model is a parallel predicate calculus based on pattern recognition and self-organization of long-term memory in a neural network. It may provide the basis for adaptive expert systems capable of inductive learning and rapid processing in a highly complex and changing environment.

  6. Fuzzy Expert System to Characterize Students

    ERIC Educational Resources Information Center

    Van Hecke, T.

    2011-01-01

    Students wanting to succeed in higher education are required to adopt an adequate learning approach. By analyzing individual learning characteristics, teachers can give personal advice to help students identify their learning success factors. An expert system based on fuzzy logic can provide economically viable solutions to help students identify…

  7. Performance Engineering as an Expert System.

    ERIC Educational Resources Information Center

    Harmon, Paul

    1984-01-01

    Considers three powerful techniques--heuristics, context trees, and search via backward chaining--that a knowledge engineer might employ to develop an expert system to automate performance engineering, i.e., the branch of instructional technology that focuses on the problems of business and industry. (MBR)

  8. Concept of an expert system for EQCreator

    NASA Astrophysics Data System (ADS)

    Schenk, Jiri; Telnarova, Zdenka; Habiballa, Hashim

    2016-06-01

    This article deals with the design of an ideal, and to some extent general, expert system for evaluation of randomly generated algebra with the help of EQCreator program, which is able to generate EQ of algebra. It was created for the purpose of future expansion of the program for the possibility of generating any algebra specified by the user.

  9. EXPERT SYSTEMS SHOW PROMISE FOR CUSTOMER INQUIRIES

    EPA Science Inventory

    This article describes results of an agreement between the North Penn Water Authority in Lansdale, Pa., and the US Environmental Protection Agency, Drinking Water Research Division, Cincinnati, Ohio, to study use of expert systems technology in a water utility. The threeyear stud...

  10. PLEXUS--The Expert System for Referral.

    ERIC Educational Resources Information Center

    Vickery, A.; Brooks, H. M.

    1987-01-01

    Presents a description of PLEXUS, an expert system on gardening designed as a referral tool for public libraries by the University of London. Highlights include determining user characteristics, developing the problem statement, the use of semantic categories, and search strategies that modify the original problem statement using Boolean…

  11. Terminological Knowledge Structure for Intermediary Expert Systems.

    ERIC Educational Resources Information Center

    Fidel, Raya; Efthimiadis, Efthimis N.

    1995-01-01

    Examines the knowledge base of an intermediary expert system that provides advice about search term selection. Topics include a proposal for an integrated approach, including an option focusing on terminological attributes based on knowledge acquired from professional searchers; and the content of the knowledge base and the research needed to…

  12. CORNELL MIXING ZONE EXPERT SYSTEM (CORMIX)

    EPA Science Inventory

    Cornell mixing zone expert system (CORMIX) can be used for the analysis, prediction, and design of aqueous toxic or conventional pollutant discharges into diverse water bodies. The major emphasis is on the geometry and dilution characteristics of the initial mixing zone -- includ...

  13. Using Expert Systems To Build Cognitive Simulations.

    ERIC Educational Resources Information Center

    Jonassen, David H.; Wang, Sherwood

    2003-01-01

    Cognitive simulations are runnable computer programs for modeling human cognitive activities. A case study is reported where expert systems were used as a formalism for modeling metacognitive processes in a seminar. Building cognitive simulations engages intensive introspection, ownership and meaning making in learners who build them. (Author/AEF)

  14. A Prototype Expert System for Fishway Design.

    ERIC Educational Resources Information Center

    Bender, Michael J.; And Others

    1992-01-01

    Describes the development of a prototype expert system to recommend the most suitable type of fishway for given design conditions. Recommendations are provided on the basis of fishway hydraulics, fish passage performance, and cost requirements. An appendix provides an example consultation. (MDH)

  15. [Expert systems and antibiotic sensitivity test].

    PubMed

    Flandrois, J; Carret, G

    1991-01-01

    Artificial intelligence is a part of computer science that deals with programs mimicking intelligence of man. Artificial intelligence is now used to check the quality of the determination of antibiotics susceptibility of bacteria. This application is useful because antibiotic susceptibility is subject to biological and technical variation that have to be detected. Three types of reasoning are used either by the biologist or by expert systems: low level quality checking dealing with individual results, microbiological interpretation of the whole set of results and medical interpretation of the results. The use of artificial intelligence in these fields is sustained by the structured nature of the knowledge. Two type of expert systems are already of routine use, either based on production rules (ATB plus EXPERT, bioMerieux, La Balme-les-Grottes, France and SIR, 12A, Montpellier, France), or on object-oriented representation of the knowledge (EXPRIM from our laboratory). The main problem is, as usually in artificial intelligence applications, to transfer human expertise into an adapted knowledge base. The advantage of experts systems over man are their reproducibility of answer and their availability. PMID:2064087

  16. Structural redundancy of dual and steel moment frame systems under seismic excitation

    NASA Astrophysics Data System (ADS)

    Song, Seung-Han

    The extensive investigation of structural failure after Northridge earthquake showed poor structural performance due to brittle member behavior and improper design. For example, the brittle steel connection fractures were totally unexpected of the highly regarded "ductile" systems. The lack of system ductile capacity and redundancy could lead to system instability and collapse. Since then, the design for redundancy has become a serious concern of both researchers and practitioners. Most reliability and redundancy studies in the past, however, have been limited to ideal simple systems. Structural redundancy under stochastic loads such as earthquakes has not been thoroughly investigated and hence not well understood or clearly defined, which could lead to misunderstandings and confusions among structural engineers. In this study, the redundancy of five-story and ten-story one-way and two-way dual systems of RC shear walls and three-story and nine-story special moment resisting frames (SMRF) is investigated in terms of system reliability. Major factors affecting redundancy considered include structural configuration (number of bays in lateral load resistance system, number and layout of shear walls, and so on), ductility capacity, uncertainty and correlation of shear wall strength. The redundancy of truly ductile SMRF systems of different configurations is also examined. A 4 x 4 bay and a 6 x 6 bay buildings of the same floor area but different numbers and sizes of beams and columns are designed and analyzed. In addition, three SMRF, 1 x 1, 2 x 2, and 3 x 3 bay systems, with torsion are investigated to examine the effect of ductile and brittle beam-column connection behaviors. The proposed uniform-risk redundancy factor is then compared with the reliability and redundancy factor (rho) in the 1996 SEAOC Blue Book, NEHRP 97, and UBC 97, which depends on the system configuration only. The results show the inadequacies of the latter approach in describing the redundancy

  17. EMCASS: Expert Motor Carrier Selection System

    SciTech Connect

    Teeters, S.W.

    1991-03-13

    The Expert Motor Carrier Selection System (EMCASS) was designed as a Knowledge-Based System to help in traffic management at Martin Marietta Energy Systems, Inc. (Energy Systems). The primary function of the system is to suggest the optimal motor carrier(s) for a given freight shipment to or from Energy Systems. The system accepts a zip code (destination or origin) from the user, a shipment weight, and other related information in some cases. EMCASS then suggests the best carrier for that shipment, and journals the results. The objective of this project is to distribute the knowledge of the company's traffic managers, and to emulate their decision processes as closely as possible.

  18. Expert Systems as a Mindtool To Facilitate Mental Model Learning.

    ERIC Educational Resources Information Center

    Mason-Mason, Susan Dale

    Expert systems are computer programs that are designed to advise or assist users by storing the knowledge of human experts and applying the computer's mathematical ability to search and sort this information. This study investigated the use of an expert system as a mindtool and whether or not creating a simple expert system would facilitate the…

  19. Linking medical records to an expert system

    NASA Technical Reports Server (NTRS)

    Naeymi-Rad, Frank; Trace, David; Desouzaalmeida, Fabio

    1991-01-01

    This presentation will be done using the IMR-Entry (Intelligent Medical Record Entry) system. IMR-Entry is a software program developed as a front-end to our diagnostic consultant software MEDAS (Medical Emergency Decision Assistance System). MEDAS (the Medical Emergency Diagnostic Assistance System) is a diagnostic consultant system using a multimembership Bayesian design for its inference engine and relational database technology for its knowledge base maintenance. Research on MEDAS began at the University of Southern California and the Institute of Critical Care in the mid 1970's with support from NASA and NSF. The MEDAS project moved to Chicago in 1982; its current progress is due to collaboration between Illinois Institute of Technology, The Chicago Medical School, Lake Forest College and NASA at KSC. Since the purpose of an expert system is to derive a hypothesis, its communication vocabulary is limited to features used by its knowledge base. The development of a comprehensive problem based medical record entry system which could handshake with an expert system while creating an electronic medical record at the same time was studied. IMR-E is a computer based patient record that serves as a front end to the expert system MEDAS. IMR-E is a graphically oriented comprehensive medical record. The programs major components are demonstrated.

  20. AFTI/F-111 MAW flight control system and redundancy management description

    NASA Technical Reports Server (NTRS)

    Larson, Richard R.

    1987-01-01

    The wing on the NASA F-111 transonic aircraft technology (TACT) airplane was modified to provide flexible leading and trailing edge flaps; this modified wing is known as the mission adaptive wing (MAW). A dual digital primary fly-by-wire flight control system was developed with analog backup reversion for redundancy. This report discusses the functions, design, and redundancy management of the flight control system for these flaps.

  1. Expert system for generating fuel movement procedures

    SciTech Connect

    Hendrickson, J.P. )

    1991-01-01

    Commercial nuclear power reactors are required by federal law and their operating license to track and control the movement of nuclear fuel. Planning nuclear fuel movements during a refueling outage by hand is a tedious process involving an initial state and final state separated by physical and administrative constraints. Since the initial and final states as well as all constraints are known, an expert computer system for planning this process is possible. Turkey Point station worked with the Electric Power Research Institute (EPRI)-selected vendor to implement such a system. Over the course of a 2-yr period, the EPRI Fuel Shuffle Planning System evolved from a high-tech word processor to an expert system capable of planning all fuel movement sequences required to refuel a nuclear reactor core. Turkey Point site is composed to two pressurized water reactor units owned and operated by Florida Power and Light Company.

  2. Demonstration of expert systems in automated monitoring

    SciTech Connect

    Otaduy, P.J.

    1985-11-01

    The Reactor Systems Section of Oak Ridge National Laboratory's Instrumentation and Controls Division has been developing expertise in the application of artificial intelligence (AI) tools and techniques to control complex systems. One of the applications developed demonstrates the capabilities of a rule-based expert system to monitor a nuclear reactor. Based on the experience acquired with the demonstration described in this paper, a 2-yr program was initiated during fiscal year 1985 for the development and implementation of an intelligent monitoring adviser to the operators of the HFIR facility. The intelligent monitoring system will act as an alert and cooperative expert to relieve the operators of routine tasks, request their attention when abnormalities are detected, and provide them with interactive diagnostic aid and project action/effects information as needed or on demand.

  3. Expert system aid for military finance

    SciTech Connect

    Morris, J.D.; Emrich, M.L.; Hwang, Ho-Ling; Meador, M.

    1987-09-14

    Historically, budget preparation processes have been difficult to accomplish. Errors and inconsistencies cause problems for the analyst during budget review. This paper discusses the development and testing of an expert system to aid budget preparation. The prototyping tool, its capabilities, and their application are discussed. Shown are the pilot testing procedures and their role in system development. Current status and enhancements (including software updates and future testing) are also presented. 12 refs., 3 figs.

  4. Development of nickel hydrogen battery expert system

    NASA Technical Reports Server (NTRS)

    Shiva, Sajjan G.

    1990-01-01

    The Hubble Telescope Battery Testbed employs the nickel-cadmium battery expert system (NICBES-2) which supports the evaluation of performances of Hubble Telescope spacecraft batteries and provides alarm diagnosis and action advice. NICBES-2 also provides a reasoning system along with a battery domain knowledge base to achieve this battery health management function. An effort to modify NICBES-2 to accommodate nickel-hydrogen battery environment in testbed is described.

  5. Exercise countermeasure protocol management expert system

    NASA Technical Reports Server (NTRS)

    Webster, L.; Chen, J. G.; Flores, L.; Tan, S.

    1993-01-01

    Exercise will be used primarily to countermeasure against deconditioning on extended space flight. In this paper we describe the development and evaluation of an expert system for exercise countermeasure protocol management. Currently, the system includes two major subsystems: baseline prescription and prescription adjustment. The baseline prescription subsystem is designed to provide initial exercise prescriptions while prescription adjustment subsystem is designed to modify the initial prescription based on the exercised progress. The system runs under three different environments: PC, SUN workstation, and Symbolic machine. The inference engine, baseline prescription module, prescription adjustment module and explanation module are developed under the Symbolic environment by using the ART (Automated Reasoning Tool) software. The Sun environment handles database management features and interfaces with PC environment to obtain physical and physiological data from exercise units on-board during the flight. Eight subjects' data have been used to evaluate the system performance by comparing the prescription of nine experienced exercise physiologists and the one prescribed by the expert system. The results of the validation test indicated that the performance of the expert system was acceptable.

  6. On the limitations of redundancies in the improvement of system reliability.

    PubMed

    Paté-Cornell, M Elisabeth; Dillon, Robin L; Guikema, Seth D

    2004-12-01

    Some program managers share a common belief that adding a redundant component to a system reduces the probability of failure by half. This is true only if the failures of the redundant components are independent events, which is rarely the case. For example, the redundant components may be subjected to the same external loads. There is, however, in general a decrease in the failure probability of the system. Nonetheless, the redundant element comes at a cost, even if it is less than that of developing the first one when both are based on the same design. Identical parts save the most in terms of design costs, but are subjected to common failure modes from possible design errors that limit the effectiveness of the redundancy. In the development of critical systems, managers thus need to decide if the costs of a parallel system are justified by the increase in the system's reliability. NASA, for example, has used redundant spacecraft to increase the chances of mission success, which worked well in the cases of the Viking and Voyager missions. These two successes, however, do not guarantee future ones. We present here a risk analysis framework accounting for dependencies to support the decision to launch at the same time a twin mission of identical spacecraft, given incremental costs and risk-reduction benefits of the second one. We illustrate this analytical approach with the case of the Mars Exploration Rovers launched by NASA in 2003, for which we had performed this assessment in 2001. PMID:15660601

  7. Practical, redundant, failure-tolerant, self-reconfiguring embedded system architecture

    DOEpatents

    Klarer, Paul R.; Hayward, David R.; Amai, Wendy A.

    2006-10-03

    This invention relates to system architectures, specifically failure-tolerant and self-reconfiguring embedded system architectures. The invention provides both a method and architecture for redundancy. There can be redundancy in both software and hardware for multiple levels of redundancy. The invention provides a self-reconfiguring architecture for activating redundant modules whenever other modules fail. The architecture comprises: a communication backbone connected to two or more processors and software modules running on each of the processors. Each software module runs on one processor and resides on one or more of the other processors to be available as a backup module in the event of failure. Each module and backup module reports its status over the communication backbone. If a primary module does not report, its backup module takes over its function. If the primary module becomes available again, the backup module returns to its backup status.

  8. Redundancy resolution of a human arm for controlling a seven DOF wearable robotic system.

    PubMed

    Kim, Hyunchul; Miller, Levi Makaio; Al-Refai, Aimen; Brand, Moshe; Rosen, Jacob

    2011-01-01

    The human arm including the shoulder, elbow, wrist joints and exclusion scapular motion has 7 Degrees of Freedom (DOF) while positioning of the wrist in space and orientating the palm is a task that requires 6 DOF. As such it includes one more DOF than is needed to complete the task. Given the redundant nature of the arm, multiple arm configurations can be used to complete a task, which is expressed mathematically by none unique solution for the inverse kinematics. Despite this mathematical difficulty, the motor control provides a unique solution for the arm redundancy as the arm is moved in space. Resolving this redundancy is becoming critical as the human interacts with a wearable robotic system(exoskeleton) which includes the same redundancy as the human arm. Therefore, the inverse kinematics solution resolving the redundancy of these two coupled systems must be identical in order to guarantee a seamless integration. The redundancy of the arm can be formulated kinematically by defining the swivel angle - the rotation angle of the plane including the upper and lower arm around a virtual axis connecting the shoulder and wrist joints which are fixed in space. Analyzing reaching tasks recorded with a motion capture lab indicates that the swivel angle is selected such that when the elbow joint is flexed, the palm points the head. Based on these experimental results, selecting the point around the center of the head as a stationary target allows to calculate the swivel angle and in that way to resolve the human arm redundancy. Experimental results indicated that by using the proposed redundancy resolution criteria the error between the predicted swivel angle and the actual swivel angle adopted by the motor control system is less then 5 Deg. This criterion or a synthesis of several additional criteria may improve the synergistic relationships between an operator and a wearable robotic system. PMID:22255087

  9. Resolution of seven-axis manipulator redundancy: A heuristic issue

    NASA Technical Reports Server (NTRS)

    Chen, I.

    1990-01-01

    An approach is presented for the resolution of the redundancy of a seven-axis manipulator arm from the AI and expert systems point of view. This approach is heuristic, analytical, and globally resolves the redundancy at the position level. When compared with other approaches, this approach has several improved performance capabilities, including singularity avoidance, repeatability, stability, and simplicity.

  10. Scientific problem solving by expert systems

    NASA Astrophysics Data System (ADS)

    Good, Ron

    Human expert problem solving in science is defined and used to account for scientific discovery. These ideas, attributed largely to Herbert Simon, are used in a description of BACON.5, a machine expert problem solver that discovers scientific laws using data-driven heuristics and expectations such as symmetry. Trial-and-error search of data-driven scientific discovery is drastically reduced when the BACON.5 system is altered to include expectations, such as symmetry, which have been influential in real (i.e., human) discoveries of scientific laws. A discussion of the implications of BACON.5-type research for traditional science education research recognizes the importance of a qualitative understanding of the relationships among pieces of a physical or biological system.

  11. The Expert Project Management System (EPMS)

    NASA Technical Reports Server (NTRS)

    Silverman, Barry G.; Diakite, Coty

    1986-01-01

    Successful project managers (PMs) have been shown to rely on 'intuition,' experience, and analogical reasoning heuristics. For new PMs to be trained and experienced PMs to avoid repeating others' mistakes, it is necessary to make the knowledge and heuristics of successful PMs more widely available. The preparers have evolved a model of PM thought processes over the last decade that is now ready to be implemented as a generic PM aid. This aid consists of a series of 'specialist' expert systems (CRITIC, LIBRARIAN, IDEA MAN, CRAFTSMAN, and WRITER) that communicate with each other via a 'blackboard' architecture. The various specialist expert systems are driven to support PM training and problem solving since any 'answers' they pass to the blackboard are subjected to conflict identification (AGENDA FORMULATOR) and GOAL SETTER inference engines.

  12. A probabilistic rule-based expert system.

    PubMed

    Todd, B S; Stamper, R; Macpherson, P

    1993-09-01

    This paper explores a medical expert system combining techniques of Bayesian network modelling with ideas of weighted inference rules. The weights of the individual rules can be estimated objectively from a training set of actual cases; and they can be used in a Monte Carlo stimulation to estimate objectively conditional probabilities of diagnosis given particular combinations of symptoms. The paper describes and evaluates a medical expert system built according to this design. The diagnostic accuracy of the program was found to be similar to that obtained through the usual application of Bayes theorem with the assumption of conditional independence of symptoms given disease, even though the Bayesian classifier has more than 70 times as many numerical parameters. The method may be promising in cases where small training sets do not permit accurate estimation of large numbers of parameters. PMID:8282430

  13. Expert system for LAN media selection

    SciTech Connect

    Johnson, M.L.; Bratten, W.A.; Williams, J.M.; Emrich, M.L.

    1988-10-01

    A continued rise in interconnectivity requirements and a shortage of experienced system integrators characterize a growing need for access to data networking information. Telecommunications personnel must make complex decisions regarding transfer media and topology. Informed decision making can be aided by an expert system capturing network planning knowledge. The LAN system has a modular architecture. It contains information regarding the design of Local Area Networks, as well as cost and time considerations. In addition, by including information regarding local constraints (e.g., equipment and distance), the system can be tailored to a new organization. 10 refs., 2 figs.

  14. HYCONES: a hybrid connectionist expert system.

    PubMed Central

    Leão, B. de F.; Reátegui, E. B.

    1993-01-01

    This paper describes HYCONES, a tightly-coupled Hybrid Connectionist Expert System that integrates neural networks with a symbolic approach (frames). The symbolic paradigm provides rich and flexible constructs to describe the domain knowledge, while the connectionist one provides the system with learning capabilities. The paper describes the architecture of the system, focusing on the hybrid aspects of the knowledge base and on its automatic knowledge acquisition technique from a case database. The first validation of the system is presented. At the end, a comparison with related research efforts and future developments are discussed. PMID:8130516

  15. Simulation Of Combat With An Expert System

    NASA Technical Reports Server (NTRS)

    Provenzano, J. P.

    1989-01-01

    Proposed expert system predicts outcomes of combat situations. Called "COBRA", combat outcome based on rules for attrition, system selects rules for mathematical modeling of losses and discrete events in combat according to previous experiences. Used with another software module known as the "Game". Game/COBRA software system, consisting of Game and COBRA modules, provides for both quantitative aspects and qualitative aspects in simulations of battles. COBRA intended for simulation of large-scale military exercises, concepts embodied in it have much broader applicability. In industrial research, knowledge-based system enables qualitative as well as quantitative simulations.

  16. Expert systems in the process industries

    NASA Technical Reports Server (NTRS)

    Stanley, G. M.

    1992-01-01

    This paper gives an overview of industrial applications of real-time knowledge based expert systems (KBES's) in the process industries. After a brief overview of the features of a KBES useful in process applications, the general roles of KBES's are covered. A particular focus is diagnostic applications, one of the major applications areas. Many applications are seen as an expansion of supervisory control. The lessons learned from numerous online applications are summarized.

  17. Building engineering expert systems in CLIPS

    NASA Technical Reports Server (NTRS)

    Porter, Ken

    1990-01-01

    This paper is intended for CLIPS developers with a working knowledge of expert systems and the CLIPS syntax. It discusses Rete pattern matching and rule-fact interaction, explains several development and debug techniques, and gives advice on compiling CLIPS and knowledge bases. The techniques apply to CLIPS versions 4.2 and 4.3, especially in the PC/DOS environment. Two examples developed by the author are analyzed and compared.

  18. Expert overseer for mass spectrometer system

    DOEpatents

    Filby, Evan E.; Rankin, Richard A.

    1991-01-01

    An expert overseer for the operation and real-time management of a mass spectrometer and associated laboratory equipment. The overseer is a computer-based expert diagnostic system implemented on a computer separate from the dedicated computer used to control the mass spectrometer and produce the analysis results. An interface links the overseer to components of the mass spectrometer, components of the laboratory support system, and the dedicated control computer. Periodically, the overseer polls these devices and as well as itself. These data are fed into an expert portion of the system for real-time evaluation. A knowledge base used for the evaluation includes both heuristic rules and precise operation parameters. The overseer also compares current readings to a long-term database to detect any developing trends using a combination of statistical and heuristic rules to evaluate the results. The overseer has the capability to alert lab personnel whenever questionable readings or trends are observed and provide a background review of the problem and suggest root causes and potential solutions, or appropriate additional tests that could be performed. The overseer can change the sequence or frequency of the polling to respond to an observation in the current data.

  19. Redundant Disk Arrays in Transaction Processing Systems. Ph.D. Thesis, 1993

    NASA Technical Reports Server (NTRS)

    Mourad, Antoine Nagib

    1994-01-01

    We address various issues dealing with the use of disk arrays in transaction processing environments. We look at the problem of transaction undo recovery and propose a scheme for using the redundancy in disk arrays to support undo recovery. The scheme uses twin page storage for the parity information in the array. It speeds up transaction processing by eliminating the need for undo logging for most transactions. The use of redundant arrays of distributed disks to provide recovery from disasters as well as temporary site failures and disk crashes is also studied. We investigate the problem of assigning the sites of a distributed storage system to redundant arrays in such a way that a cost of maintaining the redundant parity information is minimized. Heuristic algorithms for solving the site partitioning problem are proposed and their performance is evaluated using simulation. We also develop a heuristic for which an upper bound on the deviation from the optimal solution can be established.

  20. An expert system to perform on-line controller restructuring for abrupt model changes

    NASA Technical Reports Server (NTRS)

    Litt, Jonathan S.

    1990-01-01

    Work in progress on an expert system used to reconfigure and tune airframe/engine control systems on-line in real time in response to battle damage or structural failures is presented. The closed loop system is monitored constantly for changes in structure and performance, the detection of which prompts the expert system to choose and apply a particular control restructuring algorithm based on the type and severity of the damage. Each algorithm is designed to handle specific types of failures and each is applicable only in certain situations. The expert system uses information about the system model to identify the failure and to select the technique best suited to compensate for it. A depth-first search is used to find a solution. Once a new controller is designed and implemented it must be tuned to recover the original closed-loop handling qualities and responsiveness from the degraded system. Ideally, the pilot should not be able to tell the difference between the original and redesigned systems. The key is that the system must have inherent redundancy so that degraded or missing capabilities can be restored by creative use of alternate functionalities. With enough redundancy in the control system, minor battle damage affecting individual control surfaces or actuators, compressor efficiency, etc., can be compensated for such that the closed-loop performance in not noticeably altered. The work is applied to a Black Hawk/T700 system.

  1. Developing a Biomedical Expert Finding System Using Medical Subject Headings

    PubMed Central

    Singh, Reema; Malhotra, Arjun; Kaur, Manjit

    2013-01-01

    Objectives Efficient identification of subject experts or expert communities is vital for the growth of any organization. Most of the available expert finding systems are based on self-nomination, which can be biased, and are unable to rank experts. Thus, the objective of this work was to develop a robust and unbiased expert finding system which can quantitatively measure expertise. Methods Medical Subject Headings (MeSH) is a controlled vocabulary developed by the National Library of Medicine (NLM) for indexing research publications, articles and books. Using the MeSH terms associated with peer-reviewed articles published from India and indexed in PubMed, we developed a Web-based program which can be used to identify subject experts and subjects associated with an expert. Results We have extensively tested our system to identify experts from India in various subjects. The system provides a ranked list of experts where known experts rank at the top of the list. The system is general; since it uses information available with the PubMed, it can be implemented for any country. Conclusions The expert finding system is able to successfully identify subject experts in India. Our system is unique because it allows the quantification of subject expertise, thus enabling the ranking of experts. Our system is based on peer-reviewed information. Use of MeSH terms as subjects has standardized the subject terminology. The system matches requirements of an ideal expert finding system. PMID:24523988

  2. MARBLE: A system for executing expert systems in parallel

    NASA Technical Reports Server (NTRS)

    Myers, Leonard; Johnson, Coe; Johnson, Dean

    1990-01-01

    This paper details the MARBLE 2.0 system which provides a parallel environment for cooperating expert systems. The work has been done in conjunction with the development of an intelligent computer-aided design system, ICADS, by the CAD Research Unit of the Design Institute at California Polytechnic State University. MARBLE (Multiple Accessed Rete Blackboard Linked Experts) is a system of C Language Production Systems (CLIPS) expert system tool. A copied blackboard is used for communication between the shells to establish an architecture which supports cooperating expert systems that execute in parallel. The design of MARBLE is simple, but it provides support for a rich variety of configurations, while making it relatively easy to demonstrate the correctness of its parallel execution features. In its most elementary configuration, individual CLIPS expert systems execute on their own processors and communicate with each other through a modified blackboard. Control of the system as a whole, and specifically of writing to the blackboard is provided by one of the CLIPS expert systems, an expert control system.

  3. The NASA personnel security processing expert system

    SciTech Connect

    Silberberg, D.; Thomas, R.

    1996-12-31

    The NASA Personnel Security Processing Expert System is a tool that automatically determines the appropriate personnel background investigation required for a civil servant or contractor occupying a position of national security or public trust. It also instructs the personnel security processing staff to perform special checks based on a specific position. The system is implemented using a rule-based expert system and a World Wide Web interface. The system design separates the user interface, knowledge base and control structure to simplify system evolution. When one subsystem is modified, the others are impacted minimally. This system provides many benefits to the NASA Personnel Security Program. First, it frees the agency personnel security specialist from trouble-shooting and correcting all investigative problems. It also provides a learning tool for security processing staff at each installation. The system ensures that each installation security office is in compliance with all applicable laws, regulations and policies. Finally, eliminating overlapping, inappropriate and duplicative efforts to process employees saves many resources. The system was deployed less than a year ago. To date, it saved $1.2 million of the $1.5 million agency-wide personnel security budget.

  4. EXADS - EXPERT SYSTEM FOR AUTOMATED DESIGN SYNTHESIS

    NASA Technical Reports Server (NTRS)

    Rogers, J. L.

    1994-01-01

    The expert system called EXADS was developed to aid users of the Automated Design Synthesis (ADS) general purpose optimization program. Because of the general purpose nature of ADS, it is difficult for a nonexpert to select the best choice of strategy, optimizer, and one-dimensional search options from the one hundred or so combinations that are available. EXADS aids engineers in determining the best combination based on their knowledge of the problem and the expert knowledge previously stored by experts who developed ADS. EXADS is a customized application of the AESOP artificial intelligence program (the general version of AESOP is available separately from COSMIC. The ADS program is also available from COSMIC.) The expert system consists of two main components. The knowledge base contains about 200 rules and is divided into three categories: constrained, unconstrained, and constrained treated as unconstrained. The EXADS inference engine is rule-based and makes decisions about a particular situation using hypotheses (potential solutions), rules, and answers to questions drawn from the rule base. EXADS is backward-chaining, that is, it works from hypothesis to facts. The rule base was compiled from sources such as literature searches, ADS documentation, and engineer surveys. EXADS will accept answers such as yes, no, maybe, likely, and don't know, or a certainty factor ranging from 0 to 10. When any hypothesis reaches a confidence level of 90% or more, it is deemed as the best choice and displayed to the user. If no hypothesis is confirmed, the user can examine explanations of why the hypotheses failed to reach the 90% level. The IBM PC version of EXADS is written in IQ-LISP for execution under DOS 2.0 or higher with a central memory requirement of approximately 512K of 8 bit bytes. This program was developed in 1986.

  5. Fiber Optic Network Design Expert System

    NASA Astrophysics Data System (ADS)

    Artz, Timothy J.; Wnek, Roy M.

    1987-05-01

    The Fiber Optic Network Design Expert System (FONDES) is an engineering tool for the specification, design, and evaluation of fiber optic transmission systems. FONDES encompasses a design rule base and a data base of specifications of system components. This package applies to fiber optic design work in two ways, as a design-to-specification tool and a system performance prediction model. The FONDES rule base embodies the logic of design engineering. It can be used to produce a system design given a requirement specification or it can be used to predict system performance given a system design. The periodically updated FONDES data base contains performance specifications, price, and availability data for current fiber optic system components. FONDES is implemented in an artificial intelligence language, TURBO-PROLOG, and runs on an IBM-PC.

  6. EMCASS: Expert Motor Carrier Selection System

    SciTech Connect

    Teeters, S.W.

    1991-03-13

    The Expert Motor Carrier Selection System (EMCASS) was designed as a Knowledge-Based System to help in traffic management at Martin Marietta Energy Systems, Inc. (Energy Systems). The primary function of the system is to suggest the optimal motor carrier(s) for a given freight shipment to or from Energy Systems. The system accepts a zip code (destination or origin) from the user, a shipment weight, and other related information in some cases. EMCASS then suggests the best carrier for that shipment, and journals the results. The objective of this project is to distribute the knowledge of the company`s traffic managers, and to emulate their decision processes as closely as possible.

  7. FIDEX: An expert system for satellite diagnostics

    NASA Technical Reports Server (NTRS)

    Durkin, John; Tallo, Donald; Petrik, Edward J.

    1991-01-01

    A Fault Isolation and Diagnostic Expert system (FIDEX) was developed for communication satellite diagnostics. It was designed specifically for the 30/20 GHz satellite transponder. The expert system was designed with a generic structure and features that make it applicable to other types of space systems. FIDEX is a frame based system that enjoys many of the inherent frame base features, such as hierarchy that describes the transponder's components, with other hierarchies that provide structural and fault information about the transponder. This architecture provides a flexible diagnostic structure and enhances maintenance of the system. FIDEX also includes an inexact reasoning technique and a primitive learning ability. Inexact reasoning was an important feature for this system due to the sparse number of sensors available to provide information on the transponder's performance. FIDEX can determine the most likely faulted component under the constraint of limited information. FIDEX learns about the most likely faults in the transponder by keeping a record of past established faults. FIDEX also has the ability to detect anomalies in the sensors that provide information on the transponders performance.

  8. Expert systems in the olefins industry

    SciTech Connect

    Borsje, H.J.; Bowen, C.P.

    1994-12-31

    On-line Expert Systems have been used successfully in the process and manufacturing industry since the late eighties. This paper describes one of these successful applications, the Recovery Boiler Advisor{trademark}, developed for a black liquor recovery boiler in a Kraft pulp mill. The ultimate goal of this advisory system is to correctly analyze an unusual situation and help the operators make a better informed decision, and help do this quicker. The effect of the ever increasing complexity and stringency of environmental and occupational regulations in the process industry puts an additional burden on the operator that can be alleviated by smart computer systems. Advanced control algorithms process simulation, neural networks, data reconciliation and rule-based system, combined with a well designed and intuitive user interface, all contribute to the alleviation of this problem. Expert systems have found few applications in the olefins industry, despite the fact that the requirement for computer assisted plant operation has increased significantly. A number of operational issues in the ethylene plant which can benefit from on-line advisory systems are identified. It is important to recognize which necessary steps must be taken to ensure that the project results in a successful product which is accepted, understood, and properly used by the operator and by the supervisory staff. Successful projects will address an existing problem with new technology.

  9. Applying expertise to data in the Geologist's Assistant expert system

    SciTech Connect

    Berkbigler, K.P.; Papcun, G.J.; Marusak, N.L.; Hutson, J.E.

    1988-01-01

    The Geologist's Assistant combines expert system technology with numerical pattern-matching and online communication to a large database. This paper discusses the types of rules used for the expert system, the pattern-matching technique applied, and the implementation of the system using a commercial expert system development environment. 13 refs., 8 figs.

  10. An expert system for automated robotic grasping

    SciTech Connect

    Stansfield, S.A.

    1990-05-10

    Many DOE sites and facilities will be environmentally remediated during the next several decades. A number of the restoration activities (decontamination and decommissioning of inactive nuclear facilities is an example) can only be carried out by remote means and will be manipulation-intensive tasks. Experience has shown that manipulation tasks are especially slow and fatiguing for the human operator of a remote manipulator. In this paper, we present a rule-based expert system for automated, dextrous robotic grasping. This system reasons about the features of an object to generate hand shaping and wrist orientation for a robot hand and arm. The system can be used in several different ways to lessen the demands on the human operator of a remote manipulation system --- either as a fully autonomous grasping system or one which generates grasping options for a human operator and which then automatically carries out the one selected. This paper examines these systems. 2 figs.

  11. System control module diagnostic Expert Assistant

    NASA Technical Reports Server (NTRS)

    Flores, Luis M.; Hansen, Roger F.

    1990-01-01

    The Orbiter EXperiments (OEX) Program was established by NASA's Office of Aeronautics and Space Technology (OAST) to accomplish the precise data collection necessary to support a complete and accurate assessment of Space Transportation System (STS) Orbiter performance during all phases of a mission. During a mission, data generated by the various experiments are conveyed to the OEX System Control Module (SCM) which arranges for and monitors storage of the data on the OEX tape recorder. The SCM Diagnostic Expert Assistant (DEA) is an expert system which provides on demand advice to technicians performing repairs of a malfunctioning SCM. The DEA is a self-contained, data-driven knowledge-based system written in the 'C' Language Production System (CLIPS) for a portable micro-computer of the IBM PC/XT class. The DEA reasons about SCM hardware faults at multiple levels; the most detailed layer of encoded knowledge of the SCM is a representation of individual components and layouts of the custom-designed component boards.

  12. Expert systems to aid in wind farm operations

    NASA Astrophysics Data System (ADS)

    Schluter, L. L.; Nateghian, F.; Luger, G. F.

    1991-12-01

    An expert system is a knowledge-based program that provides solutions to problems in a specific domain by mimicking the behavior of a human expert. Expert systems can have several advantages over traditional programming methods; however, developing an expert system generally involves a considerable amount of time and money. Therefore, careful investigation must be done to ensure that a problem is suited for an expert system application. This paper examines several areas where an expert system may help wind farm operators lower their operational costs. Justifications for using expert systems rather than traditional programming methods are given. This paper also discusses some of the design decisions that were made in developing an expert system for US Windpower that will aid in diagnosing wind turbine failures.

  13. Analysis assessment expert system for gas chromatography

    SciTech Connect

    Elling, J.W.; Roberts, R.S.; Lahiri, S.

    1995-12-01

    An artificial intelligence based analysis assessment system is presented to automate gas chromatography instrument troubleshooting. This system is capable of recognizing symptoms of common problems with GC analysis, reasoning with the symptoms to make a problem diagnosis, and suggest appropriate solutions. In this system, signal processing techniques are used to search for symptoms of problems in the time-series data. For example, peak shapes are analyzed for fronting and tailing and the baseline is analyzed for drift and the presence of electronic spikes. A measurement of the severity of each symptom is then used by the expert system to diagnose potential problems with the analysis. This system will be integrated with the instrument control and laboratory automation that is necessary to effect the recommended solutions when possible. The result will be a more robust instrument capable of recognizing failures and error modes from the sample data and capable of correcting many of the common failures.

  14. Expert-System Consultant To Operating Personnel

    NASA Technical Reports Server (NTRS)

    Heard, Astrid E.; Pinkowski, Patrick P.; Adler, Richard M.; Hosken, R. Bruce

    1992-01-01

    Artificial intelligence aids engineers and technicians in controlling and monitoring complicated systems. Operations Analyst for Distributed Systems (OPERA) software is developmental suite of expert-system computer programs helping engineers and technicians operating from number of computer workstations to control and monitor spacecraft during prelaunch and launch phases of operation. OPERA designed to serve as consultant to operating engineers and technicians. It preprocesses incoming data, using expertise collected from conglomerate of specialists in design and operation of various parts of system. Driven by menus and mouse-activated commands. Modified versions of OPERA used in chemical-processing plants, factories, banks, and other enterprises in which there are distributed-computer systems including computers that monitor or control other computers.

  15. An expert system for automated robotic grasping

    SciTech Connect

    Stansfield, S.A. )

    1990-01-01

    Many US Department of Energy sites and facilities will be environmentally remediated during the next several decades. A number of the restoration activities (e.g., decontamination and decommissioning of inactive nuclear facilities) can only be carried out by remote means and will be manipulation-intensive tasks. Experience has shown that manipulation tasks are especially slow and fatiguing for the human operator of a remote manipulator. In this paper, the authors present a rule-based expert system for automated, dextrous robotic grasping. This system interprets the features of an object to generate hand shaping and wrist orientation for a robot hand and arm. The system can be used in several different ways to lessen the demands on the human operator of a remote manipulation system - either as a fully autonomous grasping system or one that generates grasping options for a human operator and then automatically carries out the selected option.

  16. The Workplace Exposure Assessment Expert System (WORKSPERT).

    PubMed

    Tait, K

    1992-02-01

    The fundamental principles of industrial hygiene are based upon the recognition, evaluation, and control of workplace hazards. Occupational safety and health professionals (e.g., industrial hygienists) perform this task by assessing numerous complex factors. In many situations industrial hygienists are not available; therefore, an expert system has been developed to assist the performance of workplace exposure assessments (WEAs). The Workplace Exposure Assessment Expert System (WORKSPERT) evaluates various hazardous substances, workplace conditions, and worker exposures for designated homogeneous exposure groups (HEGs). The three major components of WORKSPERT (i.e., substance, workplace, and exposure factors) are described by 27 multiple attribute variables. An air monitoring program (AMP) may be recommended for each HEG based upon the WEA. The AMP provides recommendations for an appropriate sampling strategy, sampling duration, multiple substance exposures, and number of samples to be obtained in the future. The use of WORKSPERT or other expert systems should never supersede the judgment of occupational safety and health professionals. However, WORKSPERT can be a valuable tool when used by knowledgeable, qualified technical professionals (e.g., safety and health specialists, chemists, engineers, and toxicologists) who understand the specific substance, workplace, and exposure factors for designated HEGs. WORKSPERT allows these people to benefit from the expertise of an industrial hygienist by performing systematic evaluations and obtaining recommendations for corrective actions or an AMP. The use of WORKSPERT to perform WEAs promotes the protection of workers from hazardous substances and assists compliance with occupational safety and health regulations. It also facilitates the communication of substance hazards, workplace controls, and worker exposures in a succinct manner. PMID:1543134

  17. Arrhythmia analysis with an expert system.

    PubMed

    Redman, T C; Hahn, A W

    1989-01-01

    We have developed a rule based expert system which was designed to diagnose electrocardiographic arrhythmias in several species. The program, called ECG-X, is written in OPS5 and runs under MS-DOS 2.1 and higher on an IBM-PC or AT type machine. The program uses the paper speed, the species, the temporal relationships between the P waves and the QRS complexes as well as basic information about the P and QRS morphology, and provides the user with a rhythm diagnosis consistent with rules provided by contemporary cardiac electrophysiologic knowledge. PMID:2742969

  18. A Modifiable Approach To Expert Systems Development

    NASA Astrophysics Data System (ADS)

    Sanborn, James C.

    1987-05-01

    Rule based expert systems programmers experience similar difficulties in developing and maintaining large application programs: rules become instantiated when they shouldn't the execution order of rules is undesirably nondeterministic, or worse, simply incorrect; and modifications to program behavior are difficult or unwieldy. All of these problems arise from the control strategies used by the development language, their implementation, and the programmers control over (and awareness of) them. This paper explores the impact of rule based program control on overall program modifiability. We present a language designed with efficiency, modifiability, and ease of use in mind. Throughout, we discuss traditional control strategies, improvements made through our research, and directions for further study.

  19. Development of an instructional expert system for hole drilling processes

    NASA Technical Reports Server (NTRS)

    Al-Mutawa, Souhaila; Srinivas, Vijay; Moon, Young Bai

    1990-01-01

    An expert system which captures the expertise of workshop technicians in the drilling domain was developed. The expert system is aimed at novice technicians who know how to operate the machines but have not acquired the decision making skills that are gained with experience. This paper describes the domain background and the stages of development of the expert system.

  20. Expert Graphics System Research in the Department of the Navy.

    ERIC Educational Resources Information Center

    Duff, Jon M.

    1987-01-01

    Presents current trends in the development of expert systems within the Department of the Navy, particularly research into expert graphics systems intended to support the Authoring Instructional Methods (AIM) research project. Defines artificial intelligence and expert systems. Discusses the operations and functions of the Navy's intelligent…

  1. Mastering Engineering Concepts by Building an Expert System.

    ERIC Educational Resources Information Center

    Starfield, A. M.; And Others

    1983-01-01

    Discusses the nature of and steps required in building an expert system. Includes comments by students given an assignment to choose a suitable topic and develop a small expert system related to that topic, as well as favorable faculty comments on the strategy. Also includes a student-developed expert system on rock-blasting. (JN)

  2. Design and development of the redundant launcher stabilization system for the Atlas 2 launch vehicle

    NASA Technical Reports Server (NTRS)

    Nakamura, M.

    1991-01-01

    The Launcher Stabilization System (LSS) is a pneumatic/hydraulic ground system used to support an Atlas launch vehicle prior to launch. The redesign and development activity undertaken to achieve an LSS with increased load capacity and a redundant hydraulic system for the Atlas 2 launch vehicle are described.

  3. Techniques for capturing expert knowledge - An expert systems/hypertext approach

    NASA Technical Reports Server (NTRS)

    Lafferty, Larry; Taylor, Greg; Schumann, Robin; Evans, Randy; Koller, Albert M., Jr.

    1990-01-01

    The knowledge-acquisition strategy developed for the Explosive Hazards Classification (EHC) Expert System is described in which expert systems and hypertext are combined, and broad applications are proposed. The EHC expert system is based on rapid prototyping in which primary knowledge acquisition from experts is not emphasized; the explosive hazards technical bulletin, technical guidance, and minimal interviewing are used to develop the knowledge-based system. Hypertext is used to capture the technical information with respect to four issues including procedural, materials, test, and classification issues. The hypertext display allows the integration of multiple knowlege representations such as clarifications or opinions, and thereby allows the performance of a broad range of tasks on a single machine. Among other recommendations, it is suggested that the integration of hypertext and expert systems makes the resulting synergistic system highly efficient.

  4. A PC based fault diagnosis expert system

    NASA Technical Reports Server (NTRS)

    Marsh, Christopher A.

    1990-01-01

    The Integrated Status Assessment (ISA) prototype expert system performs system level fault diagnosis using rules and models created by the user. The ISA evolved from concepts to a stand-alone demonstration prototype using OPS5 on a LISP Machine. The LISP based prototype was rewritten in C and the C Language Integrated Production System (CLIPS) to run on a Personal Computer (PC) and a graphics workstation. The ISA prototype has been used to demonstrate fault diagnosis functions of Space Station Freedom's Operation Management System (OMS). This paper describes the development of the ISA prototype from early concepts to the current PC/workstation version used today and describes future areas of development for the prototype.

  5. A Rocket Engine Design Expert System

    NASA Technical Reports Server (NTRS)

    Davidian, Kenneth J.

    1989-01-01

    The overall structure and capabilities of an expert system designed to evaluate rocket engine performance are described. The expert system incorporates a JANNAF standard reference computer code to determine rocket engine performance and a state of the art finite element computer code to calculate the interactions between propellant injection, energy release in the combustion chamber, and regenerative cooling heat transfer. Rule-of-thumb heuristics were incorporated for the H2-O2 coaxial injector design, including a minimum gap size constraint on the total number of injector elements. One dimensional equilibrium chemistry was used in the energy release analysis of the combustion chamber. A 3-D conduction and/or 1-D advection analysis is used to predict heat transfer and coolant channel wall temperature distributions, in addition to coolant temperature and pressure drop. Inputting values to describe the geometry and state properties of the entire system is done directly from the computer keyboard. Graphical display of all output results from the computer code analyses is facilitated by menu selection of up to five dependent variables per plot.

  6. A rocket engine design expert system

    NASA Technical Reports Server (NTRS)

    Davidian, Kenneth J.

    1989-01-01

    The overall structure and capabilities of an expert system designed to evaluate rocket engine performance are described. The expert system incorporates a JANNAF standard reference computer code to determine rocket engine performance and a state-of-the-art finite element computer code to calculate the interactions between propellant injection, energy release in the combustion chamber, and regenerative cooling heat transfer. Rule-of-thumb heuristics were incorporated for the hydrogen-oxygen coaxial injector design, including a minimum gap size constraint on the total number of injector elements. One-dimensional equilibrium chemistry was employed in the energy release analysis of the combustion chamber and three-dimensional finite-difference analysis of the regenerative cooling channels was used to calculate the pressure drop along the channels and the coolant temperature as it exits the coolant circuit. Inputting values to describe the geometry and state properties of the entire system is done directly from the computer keyboard. Graphical display of all output results from the computer code analyses is facilitated by menu selection of up to five dependent variables per plot.

  7. Explainable expert systems: A research program in information processing

    NASA Technical Reports Server (NTRS)

    Paris, Cecile L.

    1993-01-01

    Our work in Explainable Expert Systems (EES) had two goals: to extend and enhance the range of explanations that expert systems can offer, and to ease their maintenance and evolution. As suggested in our proposal, these goals are complementary because they place similar demands on the underlying architecture of the expert system: they both require the knowledge contained in a system to be explicitly represented, in a high-level declarative language and in a modular fashion. With these two goals in mind, the Explainable Expert Systems (EES) framework was designed to remedy limitations to explainability and evolvability that stem from related fundamental flaws in the underlying architecture of current expert systems.

  8. Expert system for first order inelastic analysis of transmission towers

    SciTech Connect

    Miller, M.; Kempner, L. Jr. ); Mueller, W. III )

    1992-01-01

    The concept of an Expert System is not new. It has been around since the days of the early computers when scientists had dreams of robot automation to do everything from washing windows to automobile design. This paper discusses an application of an expert system and addresses software development issues and various levels of expert system development form a structural engineering viewpoint. An expert system designed to aid the structural engineer in first order inelastic analysis of latticed steel transmission powers is presented. The utilization of expert systems with large numerical analysis programs is discussed along with the software development of such a system.

  9. A neural network hybrid expert system

    SciTech Connect

    Goulding, J.R. . Dept. of Mechanical Engineering)

    1991-01-01

    When knowledge-based expert rules, equations, and proprietary languages extend Computer Aided Design and Computer Aided Manufacturing (CAD CAM) software, previously designed mechanisms can be scaled to satisfy new design requirements in the shortest time. However, embedded design alternatives needed by design engineers during the product conception and rework stages are lacking, and an operator is required who has a thorough understanding of the intended design and the how-to expertise needed to create and optimize the mechanisms. By applying neural network technology to build an expert system, a robust design supervisor system emerged which automated the embedded intellectual operations (e.g. questioning, identifying, selecting, and coordinating the design process) to (1) select the best mechanisms necessary to design a power transmission gearbox from proven solutions; (2) aid the inexperienced operator in developing complex design solutions; and (3) provide design alternatives which add back-to-the-drawing board capabilities to knowledge-based mechanical CAD/CAM software programs. 15 refs., 2 figs.

  10. An Ada inference engine for expert systems

    NASA Technical Reports Server (NTRS)

    Lavallee, David B.

    1986-01-01

    The purpose is to investigate the feasibility of using Ada for rule-based expert systems with real-time performance requirements. This includes exploring the Ada features which give improved performance to expert systems as well as optimizing the tradeoffs or workarounds that the use of Ada may require. A prototype inference engine was built using Ada, and rule firing rates in excess of 500 per second were demonstrated on a single MC68000 processor. The knowledge base uses a directed acyclic graph to represent production lines. The graph allows the use of AND, OR, and NOT logical operators. The inference engine uses a combination of both forward and backward chaining in order to reach goals as quickly as possible. Future efforts will include additional investigation of multiprocessing to improve performance and creating a user interface allowing rule input in an Ada-like syntax. Investigation of multitasking and alternate knowledge base representations will help to analyze some of the performance issues as they relate to larger problems.

  11. Program for Experimentation With Expert Systems

    NASA Technical Reports Server (NTRS)

    Engle, S. W.

    1986-01-01

    CERBERUS is forward-chaining, knowledge-based system program useful for experimentation with expert systems. Inference-engine mechanism performs deductions according to user-supplied rule set. Information stored in intermediate area, and user interrogated only when no applicable data found in storage. Each assertion posed by CERBERUS answered with certainty ranging from 0 to 100 percent. Rule processor stops investigating applicable rules when goal reaches certainty of 95 percent or higher. Capable of operating for wide variety of domains. Sample rule files included for animal identification, pixel classification in image processing, and rudimentary car repair for novice mechanic. User supplies set of end goals or actions. System complexity decided by user's rule file. CERBERUS written in FORTRAN 77.

  12. Expert systems built by the Expert: An evaluation of OPS5

    NASA Technical Reports Server (NTRS)

    Jackson, Robert

    1987-01-01

    Two expert systems were written in OPS5 by the expert, a Ph.D. astronomer with no prior experience in artificial intelligence or expert systems, without the use of a knowledge engineer. The first system was built from scratch and uses 146 rules to check for duplication of scientific information within a pool of prospective observations. The second system was grafted onto another expert system and uses 149 additional rules to estimate the spacecraft and ground resources consumed by a set of prospective observations. The small vocabulary, the IF this occurs THEN do that logical structure of OPS5, and the ability to follow program execution allowed the expert to design and implement these systems with only the data structures and rules of another OPS5 system as an example. The modularity of the rules in OPS5 allowed the second system to modify the rulebase of the system onto which it was grafted without changing the code or the operation of that system. These experiences show that experts are able to develop their own expert systems due to the ease of programming and code reusability in OPS5.

  13. RAMBOT: A Connectionist Expert System That Learns by Example.

    ERIC Educational Resources Information Center

    Mozer, Michael C.

    One solution to the problem of getting expert knowledge into expert systems would be to endow the systems with powerful learning procedures that could discover appropriate behaviors by observing an expert in action. A promising source of such learning procedures can be found in recent work on connectionist networks, which are massively parallel…

  14. ART-Ada: An Ada-based expert system tool

    NASA Technical Reports Server (NTRS)

    Lee, S. Daniel; Allen, Bradley P.

    1991-01-01

    The Department of Defense mandate to standardize on Ada as the language for software systems development has resulted in increased interest in making expert systems technology readily available in Ada environments. NASA's Space Station Freedom is an example of the large Ada software development projects that will require expert systems in the 1990's. Another large scale application that can benefit from Ada based expert system tool technology is the Pilot's Associate (PA) expert system project for military combat aircraft. Automated Reasoning Tool (ART) Ada, an Ada Expert system tool is described. ART-Ada allow applications of a C-based expert system tool called ART-IM to be deployed in various Ada environments. ART-Ada is being used to implement several prototype expert systems for NASA's Space Station Freedom Program and the U.S. Air Force.

  15. ART-Ada: An Ada-based expert system tool

    NASA Technical Reports Server (NTRS)

    Lee, S. Daniel; Allen, Bradley P.

    1990-01-01

    The Department of Defense mandate to standardize on Ada as the language for software systems development has resulted in an increased interest in making expert systems technology readily available in Ada environments. NASA's Space Station Freedom is an example of the large Ada software development projects that will require expert systems in the 1990's. Another large scale application that can benefit from Ada based expert system tool technology is the Pilot's Associate (PA) expert system project for military combat aircraft. The Automated Reasoning Tool-Ada (ART-Ada), an Ada expert system tool, is explained. ART-Ada allows applications of a C-based expert system tool called ART-IM to be deployed in various Ada environments. ART-Ada is being used to implement several prototype expert systems for NASA's Space Station Freedom program and the U.S. Air Force.

  16. Triply redundant integrated navigation and asset visibility system

    SciTech Connect

    Smith, Stephen F.; Moore, James A.

    2011-11-29

    Methods and apparatus are described for a navigation system. A method includes providing a global positioning system fix having a plurality of tracking parameters; providing a theater positioning system fix; monitoring the plurality of tracking parameters for predetermined conditions; and, when the predetermined conditions are met, sending a notifying signal and switching to the theater positioning system fix as a primary fix. An apparatus includes a system controller; a global positioning system receiver coupled to the system controller; a radio frequency locating receiver coupled to the system controller; and an operator interface coupled to the system controller.

  17. Triply redundant integrated navigation and asset visibility system

    SciTech Connect

    Smith, Stephen F.; Moore, James A.

    2013-01-22

    Methods and apparatus are described for a navigation system. A method includes providing a global positioning system fix having a plurality of tracking parameters; providing a theater positioning system fix; monitoring the plurality of tracking parameters for predetermined conditions; and, when the predetermined conditions are met, sending a notifying signal and switching to the theater positioning system fix as a primary fix. An apparatus includes a system controller; a global positioning system receiver coupled to the system controller; a radio frequency locating receiver coupled to the system controller; and an operator interface coupled to the system controller.

  18. Development of casthouse expert system for tapping

    SciTech Connect

    Takihira, K.; Ino, K.; Yamana, S.; Masumoto, S.; Sugawara, H. . Ironmaking Dept.)

    1993-01-01

    Although the standardization of casting operations is necessary to secure stable blast furnace operation, intuitive practices (which are by definition non-quantifiable) and experience are prevalent. Because BF operation is a field which is difficult to standardize and reduce to documentary form, the present work had as its goal the standardization of judgments and systematization of information related to taphole opening and closing. The project was carried out in the highly computerized environment at Mizushima No. 3 BF, where the authors introduced an expert system guidance function in February, 1992. Standardization of operations through the use of this guidance system and the completion of guidance function development resulted in better consistency in taphole depths and optimization of the size of the taphole (taphole volume), which have in turn led to improvement in the pig/slag balance and a reduction in the time required for taphole opening.

  19. Approaches to the verification of rule-based expert systems

    NASA Technical Reports Server (NTRS)

    Culbert, Chris; Riley, Gary; Savely, Robert T.

    1987-01-01

    Expert systems are a highly useful spinoff of artificial intelligence research. One major stumbling block to extended use of expert systems is the lack of well-defined verification and validation (V and V) methodologies. Since expert systems are computer programs, the definitions of verification and validation from conventional software are applicable. The primary difficulty with expert systems is the use of development methodologies which do not support effective V and V. If proper techniques are used to document requirements, V and V of rule-based expert systems is possible, and may be easier than with conventional code. For NASA applications, the flight technique panels used in previous programs should provide an excellent way to verify the rules used in expert systems. There are, however, some inherent differences in expert systems that will affect V and V considerations.

  20. A diagnostic expert system for digital circuits

    NASA Astrophysics Data System (ADS)

    Backlund, R. W.; Wilson, J. D.

    1992-04-01

    A scheme is presented for a diagnostic expert system which is capable of troubleshooting a faulty digital circuit or producing a reduced test vector set for a non-faulty digital circuit. It is based on practical fault-finding logic and utilizes artificial intelligence techniques. The program uses expert knowledge comprised of two components: that which is contained within the program in the form of rules and heuristics, and that which is derived from the circuit under test in the form of specific device information. Using both forward and backward tracking algorithms, signal paths comprised of device and gate interconnections are identified from each output pin to the primary input pins which have effect on them. Beginning at the output, the program proceeds to validate each device in each signal path by forward propagating test values through the device to the output, and backward propagating the same values to the primary inputs. All devices in the circuit are monitored for each test applied and their performance is recorded. Device or gate validation occurs when the recorded history shows that a device has been toggled successfully through all necessary states. When run on a circuit which does not contain a fault, the program determines a reduced test vector set for that circuit.

  1. A expert system for locating distribution system faults

    SciTech Connect

    Hsu, Y.Y.; Lu, F.C.; Chien, Y. . Dept. of Electrical Engineering); Liu, J.P.; Lin, J.T. ); Yu, H.S.; Kuo, R.T )

    1991-01-01

    A rule-based expert system is designed to locate the faults in a distribution system. Distribution system component data and network topology are stored in the database. A set of heuristic rules are compiled from the dispatchers' experience and are imbedded in the rule base. To locate distribution system fault, an inference engine is developed to perform deductive reasonings on the rules in the knowledge base. The inference engine comprises three major parts: the dynamic searching method, the backtracking approach, and the set intersection operation. The expert system is implemented on a personal computer using the artificial intelligence language PROLOG. To demonstrate the effectiveness of the proposed approach, the expert system has been applied to locate faults in a real underground distribution system.

  2. Study of two-dimensional device-error-redundant single-electron oscillator system

    NASA Astrophysics Data System (ADS)

    Murakami, Yoshisato; Oya, Takahide

    2012-10-01

    This paper reports the study of a two-dimensional device-error-redundant single-electron (SE) circuit. The circuit is an SE reaction-diffusion (RD) circuit that imitates the unique behavior of the chemical RD system and is expected to be a new information processing system. The original RD system is a complex chemical system that is said to express selforganizing dynamics in nature. It can also be assumed to operate as parallel information processing systems. Therefore, by imitating the original RD system for SE circuits, this SE-RD circuit can perform parallel information processing that is based on a natural phenomenon. However, the circuit is very sensitive to noise because it is controlled by a very small amount of energy. It is also sensitive to device errors (e.g., circuit parameter fluctuations in the fabrication process). Generally, fluctuations caused by errors introduced in manufacturing the circuit components trigger incorrect circuit operations, including noises. To overcome such noises, the circuit requires redundant properties for noise. To address this issue, we consider mimicking the information processing method of the natural world for the circuit to obtain noise redundancy. Actually, we previously proposed a unique method based on a model of neural networks with a stochastic resonance (SR) for the circuit. The SR phenomenon, which was discovered in studies of living things (e.g., insects), can be considered a type of noise-energy-harnessing system. Many researchers have proposed SR-based applications for novel electronic devices or systems. In networks where SR exists, signals can generally be distinguished from noise by harnessing noise energy. We previously designed SE-SR systems and succeeded in making an architecture for an SE circuit that has thermal noise redundancy. At the time, we applied an SR model proposed by Collins to our circuit. Prior to our current study, however, it had not yet been confirmed whether SE circuits have device

  3. An hierarchical approach to performance evaluation of expert systems

    NASA Technical Reports Server (NTRS)

    Dominick, Wayne D. (Editor); Kavi, Srinu

    1985-01-01

    The number and size of expert systems is growing rapidly. Formal evaluation of these systems - which is not performed for many systems - increases the acceptability by the user community and hence their success. Hierarchical evaluation that had been conducted for computer systems is applied for expert system performance evaluation. Expert systems are also evaluated by treating them as software systems (or programs). This paper reports many of the basic concepts and ideas in the Performance Evaluation of Expert Systems Study being conducted at the University of Southwestern Louisiana.

  4. Expert system for spacecraft command and control

    NASA Astrophysics Data System (ADS)

    Wagner, R. E.

    The application of AI techniques to the automation of ground control functions in the defense satellite communication system (DSCS) is described. The aim of this effort is to lower the vulnerability of the DSCS to attack; a first step is the design of software for spacecraft maintenance and control. The benefits of automation and the need for high-level implementation are reviewed. A knowledge-based or expert approach was chosen to automate telemetry-interpretation, trend-analysis, anomaly-resolution, and status-maintenance functions now performed solely by operators; and a design concept was developed to meet the requirements of extendability, simplicity, and explicitness. Rule-based and logic-based knowledge-representation schemes, and data-driven and goal-driven control strategies are compared. The programming tools developed by the different organizations participating in the AI effort are indicated in a table.

  5. Low level image segmentation: an expert system.

    PubMed

    Nazif, A M; Levine, M D

    1984-05-01

    A major problem in robotic vision is the segmentation of images of natural scenes in order to understand their content. This paper presents a new solution to the image segmentation problem that is based on the design of a rule-based expert system. General knowledge about low level properties of processes employ the rules to segment the image into uniform regions and connected lines. In addition to the knowledge rules, a set of control rules are also employed. These include metarules that embody inferences about the order in which the knowledge rules are matched. They also incorporate focus of attention rules that determine the path of processing within the image. Furthermore, an additional set of higher level rules dynamically alters the processing strategy. This paper discusses the structure and content of the knowledge and control rules for image segmentation. PMID:21869225

  6. REDEX - The ranging equipment diagnostic expert system

    NASA Technical Reports Server (NTRS)

    Luczak, Edward C.; Gopalakrishnan, K.; Zillig, David J.

    1989-01-01

    REDEX, an advanced prototype expert system that diagnoses hardware failures in the Ranging Equipment (RE) at NASA's Ground Network tracking stations is described. REDEX will help the RE technician identify faulty circuit cards or modules that must be replaced, and thereby reduce troubleshooting time. It features a highly graphical user interface that uses color block diagrams and layout diagrams to illustrate the location of a fault. A semantic network knowledge representation technique was used to model the design structure of the RE. A catalog of generic troubleshooting rules was compiled to represent heuristics that are applied in diagnosing electronic equipment. Specific troubleshooting rules were identified to represent additional diagnostic knowledge that is unique to the RE. Over 50 generic and 250 specific troubleshooting rules have been derived. REDEX is implemented in Prolog on an IBM PC AT-compatible workstation. Block diagram graphics displays are color-coded to identify signals that have been monitored or inferred to have nominal values, signals that are out of tolerance, and circuit cards and functions that are diagnosed as faulty. A hypertext-like scheme is used to allow the user to easily navigate through the space of diagrams and tables. Over 50 graphic and tabular displays have been implemented. REDEX is currently being evaluated in a stand-alone mode using simulated RE fault scenarios. It will soon be interfaced to the RE and tested in an online environment. When completed and fielded, REDEX will be a concrete example of the application of expert systems technology to the problem of improving performance and reducing the lifecycle costs of operating NASA's communications networks in the 1990s.

  7. REDEX: The ranging equipment diagnostic expert system

    NASA Technical Reports Server (NTRS)

    Luczak, Edward C.; Gopalakrishnan, K.; Zillig, David J.

    1989-01-01

    REDEX, an advanced prototype expert system that diagnoses hardware failures in the Ranging Equipment (RE) at NASA's Ground Network tracking stations is described. REDEX will help the RE technician identify faulty circuit cards or modules that must be replaced, and thereby reduce troubleshooting time. It features a highly graphical user interface that uses color block diagrams and layout diagrams to illustrate the location of a fault. A semantic network knowledge representation technique was used to model the design structure of the RE. A catalog of generic troubleshooting rules was compiled to represent heuristics that are applied in diagnosing electronic equipment. Specific troubleshooting rules were identified to represent additional diagnostic knowledge that is unique to the RE. Over 50 generic and 250 specific troubleshooting rules have been derived. REDEX is implemented in Prolog on an IBM PC AT-compatible workstation. Block diagram graphics displays are color-coded to identify signals that have been monitored or inferred to have nominal values, signals that are out of tolerance, and circuit cards and functions that are diagnosed as faulty. A hypertext-like scheme is used to allow the user to easily navigate through the space of diagrams and tables. Over 50 graphic and tabular displays have been implemented. REDEX is currently being evaluated in a stand-alone mode using simulated RE fault scenarios. It will soon be interfaced to the RE and tested in an online environment. When completed and fielded, REDEX will be a concrete example of the application of expert systems technology to the problem of improving performance and reducing the lifecycle costs of operating NASA's communications networks in the 1990's.

  8. Formal specification of requirements for analytical redundancy-based fault-tolerant flight control systems

    NASA Astrophysics Data System (ADS)

    Del Gobbo, Diego

    2000-10-01

    Flight control systems are undergoing a rapid process of automation. The use of Fly-By-Wire digital flight control systems in commercial aviation (Airbus 320 and Boeing FBW-B777) is a clear sign of this trend. The increased automation goes in parallel with an increased complexity of flight control systems with obvious consequences on reliability and safety. Flight control systems must meet strict fault-tolerance requirements. The standard solution to achieving fault tolerance capability relies on multi-string architectures. On the other hand, multi-string architectures further increase the complexity of the system inducing a reduction of overall reliability. In the past two decades a variety of techniques based on analytical redundancy have been suggested for fault diagnosis purposes. While research on analytical redundancy has obtained desirable results, a design methodology involving requirements specification and feasibility analysis of analytical redundancy based fault tolerant flight control systems is missing. The main objective of this research work is to describe within a formal framework the implications of adopting analytical redundancy as a basis to achieve fault tolerance. The research activity involves analysis of the analytical redundancy approach, analysis of flight control system informal requirements, and re-engineering (modeling and specification) of the fault tolerance requirements. The USAF military specification MIL-F-9490D and supporting documents are adopted as source for the flight control informal requirements. The De Havilland DHC-2 general aviation aircraft equipped with standard autopilot control functions is adopted as pilot application. Relational algebra is adopted as formal framework for the specification of the requirements. The detailed analysis and formalization of the requirements resulted in a better definition of the fault tolerance problem in the framework of analytical redundancy. Fault tolerance requirements and related

  9. 77 FR 28797 - Redundancy of Communications Systems: Backup Power Private Land Mobile Radio Services: Selection...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-16

    ... From the Federal Register Online via the Government Publishing Office FEDERAL COMMUNICATIONS COMMISSION 47 CFR Parts 12 and 90 Redundancy of Communications Systems: Backup Power Private Land Mobile Radio Services: Selection and Assignment of Frequencies, and Transition of the Upper 200 Channels in...

  10. Successful expert systems for space shuttle payload integration

    NASA Technical Reports Server (NTRS)

    Morris, Keith

    1988-01-01

    Expert systems are successfully applied to solve recurring NASA Space Shuttle orbiter payload integration problems. Recurrence of these problems is the result of each Space Shuttle mission being unique. The NASA Space Shuttle orbiter was designed to be extremely flexible in its ability to handle many types and combinations of satellites and experiments. This flexibility results in different and unique engineering resource requirements for each of the payload satellites and experiments. The first successful expert system to be applied to these problems was the Orbiter Payload Bay Cabling Expert System (EXCABL), developed at Rockwell International Space Transportation Systems Division. The operational version of EXCABL was delivered in 1986 and successfully solved the payload electrical support services cabling layout problem. As a result of this success, a second expert system, Expert Drawing Matching System (EXMATCH), was developed to generate a list of the reusable installation drawings available for each EXCABL solution. EXMATCH went operational in 1987. As a result of these initial successes, the need for a third expert system was defined and is awaiting development. This new Expert System, called Technical Order Listing Expert System (EXTOL), will generate a list of all the applicable reusable installation drawings available to support the total payload bay mission provisioning and installation effort. This paper describes these expert systems, the individual problems that they were designed to solve, their individual solutions, and the degree of success achieved. These expert systems' instantiate the applicability of this technology to the solution of real-world Space Shuttle payload integration problems.

  11. CLIPS: An expert system tool for delivery and training

    NASA Technical Reports Server (NTRS)

    Riley, Gary; Culbert, Chris; Savely, Robert T.; Lopez, Frank

    1987-01-01

    The C Language Integrated Production System (CLIPS) is a forward chaining rule-based language. The requirements necessary for an expert system tool which is used for development, delivery, and training are examined. Because of its high portability, low cost, and ease of integration with external systems, CLIPS has great potential as an expert system tool for delivery and training. In addition, its representation flexibility, debugging aids, and performance, along with its other strengths, make it a viable alternative for expert system development.

  12. Expert system to control a fusion energy experiment

    SciTech Connect

    Johnson, R.R.; Canales, T.; Lager, D.

    1986-01-01

    This paper describes a system that automates neutral beam source conditioning. The system achieves this with artificial intelligence techniques by encoding the behavior of several experts as a set of if-then rules in an expert system. One of the functions of the expert system is to control an adaptive controller that, in turn, controls the neutral beam source. The architecture of the system is presented followed by a description of its performance.

  13. Evaluation of software based redundancy algorithms for the EOS storage system at CERN

    NASA Astrophysics Data System (ADS)

    Peters, Andreas-Joachim; Alin Sindrilaru, Elvin; Zigann, Philipp

    2012-12-01

    EOS is a new disk based storage system used in production at CERN since autumn 2011. It is implemented using the plug-in architecture of the XRootD software framework and allows remote file access via XRootD protocol or POSIX-like file access via FUSE mounting. EOS was designed to fulfill specific requirements of disk storage scalability and IO scheduling performance for LHC analysis use cases. This is achieved by following a strategy of decoupling disk and tape storage as individual storage systems. A key point of the EOS design is to provide high availability and redundancy of files via a software implementation which uses disk-only storage systems without hardware RAID arrays. All this is aimed at reducing the overall cost of the system and also simplifying the operational procedures. This paper presents the advantages and disadvantages of redundancy by hardware (most classical storage installations) in comparison to redundancy by software. The latter is implemented in the EOS system and achieves its goal by spawning data and parity stripes via remote file access over nodes. The gain in redundancy and reliability comes with a trade-off in the following areas: • Increased complexity of the network connectivity • CPU intensive parity computations during file creation and recovery • Performance loss through remote disk coupling An evaluation and performance figures of several redundancy algorithms are presented for dual parity RAID and Reed-Solomon codecs. Moreover, the characteristics and applicability of these algorithms are discussed in the context of reliable data storage systems.

  14. A Method for Exploiting Redundancy to Accommodate Actuator Limits in Multivariable Systems

    NASA Technical Reports Server (NTRS)

    Litt, Jonathan; Roulette, Greg

    1995-01-01

    This paper introduces a new method for accommodating actuator saturation in a multivariable system with actuator redundancy. Actuator saturation can cause significant deterioration in control system performance because unmet demand may result in sluggish transients and oscillations in response to setpoint changes. To help compensate for this problem, a technique has been developed which takes advantage of redundancy in multivariable systems to redistribute the unmet control demand over the remaining useful effectors. This method is not a redesign procedure, rather it modifies commands to the unlimited effectors to compensate for those which are limited, thereby exploiting the built-in redundancy. The original commands are modified by the increments due to unmet demand, but when a saturated effector comes off its limit, the incremental commands disappear and the original unmodified controller remains intact. This scheme provides a smooth transition between saturated and unsaturated modes as it divides up the unmet requirement over any available actuators. This way, if there is sufficiently redundant control authority, performance can be maintained.

  15. Expert Systems--A Competent Tool for Training?

    ERIC Educational Resources Information Center

    Shaoul, Jean; Smith, P. J.

    Expert systems, rule-based knowledge systems, have been widely heralded as an important tool in management and accounting. Expert system shells have become available for personal computers, and accountants are investing in systems which are supposed to be capable of intelligent decisions. The limitations of rule-based knowledge systems are…

  16. Expert systems for real-time monitoring and fault diagnosis

    NASA Technical Reports Server (NTRS)

    Edwards, S. J.; Caglayan, A. K.

    1989-01-01

    Methods for building real-time onboard expert systems were investigated, and the use of expert systems technology was demonstrated in improving the performance of current real-time onboard monitoring and fault diagnosis applications. The potential applications of the proposed research include an expert system environment allowing the integration of expert systems into conventional time-critical application solutions, a grammar for describing the discrete event behavior of monitoring and fault diagnosis systems, and their applications to new real-time hardware fault diagnosis and monitoring systems for aircraft.

  17. Differential diagnosis of allergic rhinitis and sinusitis an expert system

    SciTech Connect

    Creider, R.D.; Sundar Singh, P.S.

    1996-12-31

    Nasal congestion is a common problem for many people. It is a symptom of chronic sinusitis and also a characteristic of allergic rhinitis. Individuals frequently confuse sinusitis and allergic rhinitis. The expert system described below will diagnose the problem to be either rhinitis or sinusitis. In this paper we describe the expert system, the need for such an expert system and the process of developing the system.

  18. Factors which Limit the Value of Additional Redundancy in Human Rated Launch Vehicle Systems

    NASA Technical Reports Server (NTRS)

    Anderson, Joel M.; Stott, James E.; Ring, Robert W.; Hatfield, Spencer; Kaltz, Gregory M.

    2008-01-01

    The National Aeronautics and Space Administration (NASA) has embarked on an ambitious program to return humans to the moon and beyond. As NASA moves forward in the development and design of new launch vehicles for future space exploration, it must fully consider the implications that rule-based requirements of redundancy or fault tolerance have on system reliability/risk. These considerations include common cause failure, increased system complexity, combined serial and parallel configurations, and the impact of design features implemented to control premature activation. These factors and others must be considered in trade studies to support design decisions that balance safety, reliability, performance and system complexity to achieve a relatively simple, operable system that provides the safest and most reliable system within the specified performance requirements. This paper describes conditions under which additional functional redundancy can impede improved system reliability. Examples from current NASA programs including the Ares I Upper Stage will be shown.

  19. Expert systems guide biological phosphorus removal

    SciTech Connect

    Krichten, D.J.; Wilson, K.D.; Tracy, K.D. )

    1991-10-01

    There is a large body of knowledge regarding optimum control strategies for new secondary wastewater treatment technology using an anaerobic selector to provide biological phosphorus removal. However, because the selector technology is new and the concepts differ somewhat from those used in conventional activated sludge wastewater treatment, a method of communicating this knowledge to plant operators is needed. Traditional methods such as classroom training and operating manuals are of limited effectiveness. The commonplace availability and low cost of the personal computer (PC) makes it practical to use a computer program to communicate the type of information required to control a wastewater treatment plant. Knowledge-based systems technology, commonly referred to as expert systems (ES) technology, is easy to use, provides useful information regarding a consistent control strategy, relieves the anxiety associated with learning a new process,' and provides instruction for inexperienced personnel. ES technology does not require special formatted input and is therefore easily accessible. All information required by the program is readily available through routine laboratory analysis, common plant instrumentation, or direct user observation. The program was designed for all levels of computer users and will run on all IBM-compatible or Apple MacIntosh systems.

  20. Reliability and mass analysis of dynamic power conversion systems with parallel of standby redundancy

    NASA Technical Reports Server (NTRS)

    Juhasz, A. J.; Bloomfield, H. S.

    1985-01-01

    A combinatorial reliability approach is used to identify potential dynamic power conversion systems for space mission applications. A reliability and mass analysis is also performed, specifically for a 100 kWe nuclear Brayton power conversion system with parallel redundancy. Although this study is done for a reactor outlet temperature of 1100K, preliminary system mass estimates are also included for reactor outlet temperatures ranging up to 1500 K.

  1. Reliability and mass analysis of dynamic power conversion systems with parallel or standby redundancy

    NASA Technical Reports Server (NTRS)

    Juhasz, Albert J.; Bloomfield, Harvey S.

    1987-01-01

    A combinatorial reliability approach was used to identify potential dynamic power conversion systems for space mission applications. A reliability and mass analysis was also performed, specifically for a 100-kWe nuclear Brayton power conversion system with parallel redundancy. Although this study was done for a reactor outlet temperature of 1100 K, preliminary system mass estimates are also included for reactor outlet temperatures ranging up to 1500 K.

  2. Optimal Redundancy Management in Reconfigurable Control Systems Based on Normalized Nonspecificity

    NASA Technical Reports Server (NTRS)

    Wu, N.Eva; Klir, George J.

    1998-01-01

    In this paper the notion of normalized nonspecificity is introduced. The nonspecifity measures the uncertainty of the estimated parameters that reflect impairment in a controlled system. Based on this notion, a quantity called a reconfiguration coverage is calculated. It represents the likelihood of success of a control reconfiguration action. This coverage links the overall system reliability to the achievable and required control, as well as diagnostic performance. The coverage, when calculated on-line, is used for managing the redundancy in the system.

  3. Verification of Triple Modular Redundancy Insertion for Reliable and Trusted Systems

    NASA Technical Reports Server (NTRS)

    Berg, Melanie; LaBel, Kenneth

    2016-01-01

    If a system is required to be protected using triple modular redundancy (TMR), improper insertion can jeopardize the reliability and security of the system. Due to the complexity of the verification process and the complexity of digital designs, there are currently no available techniques that can provide complete and reliable confirmation of TMR insertion. We propose a method for TMR insertion verification that satisfies the process for reliable and trusted systems.

  4. The application of expert systems to process control

    NASA Astrophysics Data System (ADS)

    Wu, Bevan P. F.

    1991-01-01

    An expert system is a computer software technology developed from artificial intelligence research. It may be used for intelligent manufacturing process control and, when properly designed, has the capability to imitate human behavior. An expert system's value is to assist a human in executing realtime process control decisions in a complex system. This article provides an introduction to the concepts of intelligent process control and includes a process control scenario applying an expert system as well as statistical and optimization technologies. A simple guide of how to get started and a description of expert system tools are also presented.

  5. Self-actuating heat switches for redundant refrigeration systems

    NASA Technical Reports Server (NTRS)

    Chan, Chung K. (Inventor)

    1988-01-01

    A dual refrigeration system for cooling a sink device is described, which automatically thermally couples the cold refrigerator to the sink device while thermally isolating the warm refrigerator from the sink device. The system includes two gas gap heat switches that each thermally couples one of the refrigerators to the sink device, and a pair of sorption pumps that are coupled through tubes to the heat switches. When the first refrigerator is operated and therefore cold, the first pump which is thermally coupled to it is also cooled and adsorbs gas to withdraw it from the second heat switch, to thereby thermally isolate the sink device from the warm second refrigerator. With the second refrigerator being warm, the second pump is also warm and desorbs gas, so the gas lies in the first switch, to close that switch and therefore thermally couple the cold first refrigerator to the sink device. Thus, the heat switches are automatically switched according to the temperature of the corresponding refrigerator.

  6. Redundancy management of multiple inertial systems for Space Shuttle.

    NASA Technical Reports Server (NTRS)

    Dove, D. W.; Mckern, R. A.

    1972-01-01

    Failure detection and isolation techniques are developed for application to off-the-shelf type four-gimbaled inertial measurement units such as the KT-70 or Carousel IV. By using simulated boost and entry shuttle trajectories with specific gimbaled IMU models, failure detection thresholds are developed based upon red-line life dependent requirements and warning thresholds are given within the red-line thresholds based upon expected worst case IMU performance. Using these trajectories, established trajectory thresholds, and multiple IMU models, various failure detection and isolation techniques are evaluated for application in both powered and unpowered flight phases. The adequacy of off-the-shelf systems for both attitude and velocity detection methods is evaluated and recommendations for shuttle application are made.

  7. SSME fault monitoring and diagnosis expert system

    NASA Technical Reports Server (NTRS)

    Ali, Moonis; Norman, Arnold M.; Gupta, U. K.

    1989-01-01

    An expert system, called LEADER, has been designed and implemented for automatic learning, detection, identification, verification, and correction of anomalous propulsion system operations in real time. LEADER employs a set of sensors to monitor engine component performance and to detect, identify, and validate abnormalities with respect to varying engine dynamics and behavior. Two diagnostic approaches are adopted in the architecture of LEADER. In the first approach fault diagnosis is performed through learning and identifying engine behavior patterns. LEADER, utilizing this approach, generates few hypotheses about the possible abnormalities. These hypotheses are then validated based on the SSME design and functional knowledge. The second approach directs the processing of engine sensory data and performs reasoning based on the SSME design, functional knowledge, and the deep-level knowledge, i.e., the first principles (physics and mechanics) of SSME subsystems and components. This paper describes LEADER's architecture which integrates a design based reasoning approach with neural network-based fault pattern matching techniques. The fault diagnosis results obtained through the analyses of SSME ground test data are presented and discussed.

  8. Constructivist Uses of Expert Systems to Support Learning.

    ERIC Educational Resources Information Center

    Jonassen, David H.; And Others

    1993-01-01

    Discusses constructivist uses of production rule expert systems that may be used to support learning for secondary and higher education. Highlights include locus of control; and objectivist and constructivist applications of expert systems as intelligent tutoring systems, as feedback systems, as personal knowledge representation tools, and for…

  9. The theory of diversity and redundancy in information system security : LDRD final report.

    SciTech Connect

    Mayo, Jackson R.; Torgerson, Mark Dolan; Walker, Andrea Mae; Armstrong, Robert C.; Allan, Benjamin A.; Pierson, Lyndon George

    2010-10-01

    The goal of this research was to explore first principles associated with mixing of diverse implementations in a redundant fashion to increase the security and/or reliability of information systems. Inspired by basic results in computer science on the undecidable behavior of programs and by previous work on fault tolerance in hardware and software, we have investigated the problem and solution space for addressing potentially unknown and unknowable vulnerabilities via ensembles of implementations. We have obtained theoretical results on the degree of security and reliability benefits from particular diverse system designs, and mapped promising approaches for generating and measuring diversity. We have also empirically studied some vulnerabilities in common implementations of the Linux operating system and demonstrated the potential for diversity to mitigate these vulnerabilities. Our results provide foundational insights for further research on diversity and redundancy approaches for information systems.

  10. An expert system development methodology which supports verification and validation

    NASA Technical Reports Server (NTRS)

    Culbert, Chris; Riley, Gary; Savely, Robert T.

    1987-01-01

    Expert systems have demonstrated commercial viability in a wide range of applications, but still face some obstacles to widespread use. A major stumbling block is the lack of well defined verification and validation (V and V) techniques. The primary difficulty with expert system V and V is the use of development methodologies which do not support V and V. As with conventional code, the key to effective V and V is the development methodology. An expert system development methodology is described which is based upon a panel review approach, that allows input from all parties concerned with the expert system.

  11. Three CLIPS-based expert systems for solving engineering problems

    NASA Technical Reports Server (NTRS)

    Parkinson, W. J.; Luger, G. F.; Bretz, R. E.

    1990-01-01

    We have written three expert systems, using the CLIPS PC-based expert system shell. These three expert systems are rule based and are relatively small, with the largest containing slightly less than 200 rules. The first expert system is an expert assistant that was written to help users of the ASPEN computer code choose the proper thermodynamic package to use with their particular vapor-liquid equilibrium problem. The second expert system was designed to help petroleum engineers choose the proper enhanced oil recovery method to be used with a given reservoir. The effectiveness of each technique is highly dependent upon the reservoir conditions. The third expert system is a combination consultant and control system. This system was designed specifically for silicon carbide whisker growth. Silicon carbide whiskers are an extremely strong product used to make ceramic and metal composites. The manufacture of whiskers is a very complicated process. which to date. has defied a good mathematical model. The process was run by experts who had gained their expertise by trial and error. A system of rules was devised by these experts both for procedure setup and for the process control. In this paper we discuss the three problem areas of the design, development and evaluation of the CLIPS-based programs.

  12. Autonomous control system reconfiguration for spacecraft with non-redundant actuators

    NASA Technical Reports Server (NTRS)

    Grossman, Walter

    1995-01-01

    The Small Satellite Technology Initiative (SSTI) 'CLARK' spacecraft is required to be single-failure tolerant, i.e., no failure of any single component or subsystem shall result in complete mission loss. Fault tolerance is usually achieved by implementing redundant subsystems. Fault tolerant systems are therefore heavier and cost more to build and launch than non-redundent, non fault-tolerant spacecraft. The SSTI CLARK satellite Attitude Determination and Control System (ADACS) achieves single-fault tolerance without redundancy. The attitude determination system system uses a Kalman Filter which is inherently robust to loss of any single attitude sensor. The attitude control system uses three orthogonal reaction wheels for attitude control and three magnetic dipoles for momentum control. The nominal six-actuator control system functions by projecting the attitude correction torque onto the reaction wheels while a slower momentum management outer loop removes the excess momentum in the direction normal to the local B field. The actuators are not redundant so the nominal control law cannot be implemented in the event of a loss of a single actuator (dipole or reaction wheel). The spacecraft dynamical state (attitude, angular rate, and momentum) is controllable from any five-element subset of the six actuators. With loss of an actuator the instantaneous control authority may not span R(3) but the controllability gramian integral(limits between t,0) Phi(t, tau)B(tau )B(prime)(tau) Phi(prime)(t, tau)d tau retains full rank. Upon detection of an actuator failure the control torque is decomposed onto the remaining active axes. The attitude control torque is effected and the over-orbit momentum is controlled. The resulting control system performance approaches that of the nominal system.

  13. Optimal inventories for overhaul of repairable redundant systems - A Markov decision model

    NASA Technical Reports Server (NTRS)

    Schaefer, M. K.

    1984-01-01

    A Markovian decision model was developed to calculate the optimal inventory of repairable spare parts for an avionics control system for commercial aircraft. Total expected shortage costs, repair costs, and holding costs are minimized for a machine containing a single system of redundant parts. Transition probabilities are calculated for each repair state and repair rate, and optimal spare parts inventory and repair strategies are determined through linear programming. The linear programming solutions are given in a table.

  14. EDECS: the Emergency Department Expert Charting System.

    PubMed

    Schriger, D L; Baraff, L J; Hassanvand, M; Nagda, S

    1995-01-01

    EDECS, the Emergency Department Expert Charting System, integrates clinical guidelines into the everyday practice of medicine. By generating the medical record and patient aftercare instructions, it facilitates patient care. For this reason, doctors are willing to use it. While using it, the doctors are continually presented with advice regarding documentation, testing, and treatment. Unlike guidelines that attempt to modify behavior through traditional educational methods, these computerized guidelines are seen by the physician every time she sees a patient. We have demonstrated this by directly integrating the guidelines into the process of patient care; we can increase compliance with the guidelines [1]. At present EDECS exists for the chief complaints of occupational exposure to body fluids, acute low back pain, recurrent seizure, fever in children, and males with penile discharge or dysuria. Upon examining the patient, the physician proceeds to the computer, which prompts him for essential information regarding the history and physical examination. Certain items are required for all patients with the chief complaint, others are required based on the answers to these items. Data is analyzed by the computer, which provides advice regarding testing and treatment. Once testing is completed, the system suggests a probable diagnosis and aids in patient disposition and discharge planning. Finally, EDECS prints the medical record as well as patient-specific aftercare instructions. EDECS is a user friendly system; most data is entered via mouse. It is written in the OS-based expert system shell AM(TM) and can be run on an IBM compatible PC or PC network. Rules are generally written in an "if...then" format, but more sophisticated rule structures, including Bayesian models, are used when needed. Each module contains separate subroutines for the history, physical, laboratory ordering, treatment, and disposition. These modules call each other in a dynamic fashion. The

  15. Automatic Recognition of Ocean Structures from Satellite Images by Means of Neural Nets and Expert Systems

    NASA Astrophysics Data System (ADS)

    Guindos-Rojas, F.; Cantón-Garbín, M.; Torres-Arriaza, J. A.; Peralta-López, M.; Piedra-Fernández, J. A.; Molina-Martínez, A.

    2004-09-01

    Images received from satellites have became a great source of information about our environment. This is raw information that needs experts to make the most of it, but there are not many experts and the work is too much. The solution to this problem is the compilation of human experience into automatic systems that could do the same work. We depict here the structure for a knowledge based system capable of taking the place of human experts when it is properly trained. This structure has been used to build an automatic recognition system that process AVHRR images from NOAA satellites to detect and locate ocean phenomena of interest like upwellings, eddies and island wakes. The model covers every phase of the process from the source image, once it is corrected and geocoded, to the final features map. In the most delicate phase of the process pipeline, artificial neural nets and rule-based expert systems are used in a parallel redundant way so results can be validated by comparing the outcome of both subsystems. The automatic knowledge driven image processing system has been trained with ubiquitous and localized information and has proved his qualities with images of Canary Island, Mediterranean Sea and Cantabric and Portuguese coasts.

  16. Expert Systems as Cognitive Models for Intelligent Tutors.

    ERIC Educational Resources Information Center

    Randolph, Gary L.

    1988-01-01

    Evaluates present conditions and recognizes current methodology being used for rule-based systems and schema-based systems, and gives examples of these systems. Lists educational implications of artificial intelligence and expert systems. (MVL)

  17. Expert verification of the knowledge base of FEED--a feedback expert system for EMS documentation.

    PubMed

    Saini, Devashish; Orthner, Helmuth F; Berner, Eta S; Mirza, Muzna; Godwin, Charles J; Brown, Todd B

    2008-01-01

    Feedback Expert System for Emergency Medical Services (EMS) Documentation (FEED) has a rule-based knowledge base (KB) that was verified against specifications in a focus group consisting of six experts. The focus group suggested changes in almost all rules discussed, indicating that the KB did not meet specifications at that stage of development. However, enough information was gathered to address these issues in the next iteration of development. PMID:18999259

  18. Redundancy management for efficient fault recovery in NASA's distributed computing system

    NASA Technical Reports Server (NTRS)

    Malek, Miroslaw; Pandya, Mihir; Yau, Kitty

    1991-01-01

    The management of redundancy in computer systems was studied and guidelines were provided for the development of NASA's fault-tolerant distributed systems. Fault recovery and reconfiguration mechanisms were examined. A theoretical foundation was laid for redundancy management by efficient reconfiguration methods and algorithmic diversity. Algorithms were developed to optimize the resources for embedding of computational graphs of tasks in the system architecture and reconfiguration of these tasks after a failure has occurred. The computational structure represented by a path and the complete binary tree was considered and the mesh and hypercube architectures were targeted for their embeddings. The innovative concept of Hybrid Algorithm Technique was introduced. This new technique provides a mechanism for obtaining fault tolerance while exhibiting improved performance.

  19. Electronic "Expert Systems" Make Light Work of Paperwork.

    ERIC Educational Resources Information Center

    Trotter, Andrew

    1990-01-01

    Expert systems offer school possibilities beyond relieving employees of routine work. In the future, expert systems will become tools for budgeting, staff training, and teaching. Describes a system developed at Utah State University, "Mandate Consultant," that helps school staff review the legally mandated steps in developing individualized…

  20. Expert Systems in ARL Libraries. SPEC Kit 174.

    ERIC Educational Resources Information Center

    Bailey, Charles W., Jr., Comp.; Myers, Judy E., Comp.

    This Systems and Procedures Exchange Center (SPEC) kit presents the results of a survey of library members of the Association of Research Libraries (ARL) which assessed their perceptions of expert systems and determined their level of expert system development activity; 78 of these ARL libraries returned useable surveys, and 7 submitted planning…

  1. An Adaptive Technique for a Redundant-Sensor Navigation System. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Chien, T. T.

    1972-01-01

    An on-line adaptive technique is developed to provide a self-contained redundant-sensor navigation system with a capability to utilize its full potentiality in reliability and performance. The gyro navigation system is modeled as a Gauss-Markov process, with degradation modes defined as changes in characteristics specified by parameters associated with the model. The adaptive system is formulated as a multistage stochastic process: (1) a detection system, (2) an identification system and (3) a compensation system. It is shown that the sufficient statistics for the partially observable process in the detection and identification system is the posterior measure of the state of degradation, conditioned on the measurement history.

  2. Experiments with rule writer, a tool for building expert systems

    SciTech Connect

    Drastal, G.A.

    1984-01-01

    This paper discusses some results of experiments with rule writer, an artificial intelligence system that assists knowledge engineers with the task of writing inference rules for a rule-based expert consultation system. Rule writer (RW) is a tool for building models of medical diagnosis in the expert formalism. RW is used primarily in an early stage of expert system development, to generate a prototype rule base. In addition, RW is a testbed for experimenting with alternative organizations of expert knowledge in an inference rule representation. 4 references.

  3. Executing CLIPS expert systems in a distributed environment

    NASA Technical Reports Server (NTRS)

    Taylor, James; Myers, Leonard

    1990-01-01

    This paper describes a framework for running cooperating agents in a distributed environment to support the Intelligent Computer Aided Design System (ICADS), a project in progress at the CAD Research Unit of the Design Institute at the California Polytechnic State University. Currently, the systems aids an architectural designer in creating a floor plan that satisfies some general architectural constraints and project specific requirements. At the core of ICADS is the Blackboard Control System. Connected to the blackboard are any number of domain experts called Intelligent Design Tools (IDT). The Blackboard Control System monitors the evolving design as it is being drawn and helps resolve conflicts from the domain experts. The user serves as a partner in this system by manipulating the floor plan in the CAD system and validating recommendations made by the domain experts. The primary components of the Blackboard Control System are two expert systems executed by a modified CLIPS shell. The first is the Message Handler. The second is the Conflict Resolver. The Conflict Resolver synthesizes the suggestions made by the domain experts, which can be either CLIPS expert systems, or compiled C programs. In DEMO1, the current ICADS prototype, the CLIPS domain expert systems are Acoustics, Lighting, Structural, and Thermal; the compiled C domain experts are the CAD system and the User Interface.

  4. Genetic algorithm testbed for expert system testing. Final report

    SciTech Connect

    Roache, E.

    1996-01-01

    In recent years, the electric utility industry has developed advisory and control software that makes use of expert system technology. The validation of the underlying knowledge representation in these expert systems is critical to their success. Most expert systems currently deployed have been validated by certifying that the expert system provides appropriate conclusions for specific test cases. While this type of testing is important, it does not test cases where unexpected inputs are presented to the expert system and potential errors are exposed. Exhaustive testing is not typically an option due to the complexity of the knowledge representation and the combinatorial effects associated with checking all possible inputs through all possible execution paths. Genetic algorithms are general purpose search techniques modeled on natural adaptive systems and selective breeding methods. Genetic algorithms have been used successfully for parameter optimization and efficient search. The goal of this project was to confirm or reject the hypothesis that genetic algorithms (GAs) are useful in expert system validation. The GA system specifically targeted errors in the study`s expert system that would be exposed by unexpected input cases. The GA system found errors in the expert system and the hypothesis was confirmed. This report describes the process and results of the project.

  5. Exploration of synergistic and redundant information sharing in static and dynamical Gaussian systems

    NASA Astrophysics Data System (ADS)

    Barrett, Adam B.

    2015-05-01

    To fully characterize the information that two source variables carry about a third target variable, one must decompose the total information into redundant, unique, and synergistic components, i.e., obtain a partial information decomposition (PID). However, Shannon's theory of information does not provide formulas to fully determine these quantities. Several recent studies have begun addressing this. Some possible definitions for PID quantities have been proposed and some analyses have been carried out on systems composed of discrete variables. Here we present an in-depth analysis of PIDs on Gaussian systems, both static and dynamical. We show that, for a broad class of Gaussian systems, previously proposed PID formulas imply that (i) redundancy reduces to the minimum information provided by either source variable and hence is independent of correlation between sources, and (ii) synergy is the extra information contributed by the weaker source when the stronger source is known and can either increase or decrease with correlation between sources. We find that Gaussian systems frequently exhibit net synergy, i.e., the information carried jointly by both sources is greater than the sum of information carried by each source individually. Drawing from several explicit examples, we discuss the implications of these findings for measures of information transfer and information-based measures of complexity, both generally and within a neuroscience setting. Importantly, by providing independent formulas for synergy and redundancy applicable to continuous time-series data, we provide an approach to characterizing and quantifying information sharing amongst complex system variables.

  6. Exploration of synergistic and redundant information sharing in static and dynamical Gaussian systems.

    PubMed

    Barrett, Adam B

    2015-05-01

    To fully characterize the information that two source variables carry about a third target variable, one must decompose the total information into redundant, unique, and synergistic components, i.e., obtain a partial information decomposition (PID). However, Shannon's theory of information does not provide formulas to fully determine these quantities. Several recent studies have begun addressing this. Some possible definitions for PID quantities have been proposed and some analyses have been carried out on systems composed of discrete variables. Here we present an in-depth analysis of PIDs on Gaussian systems, both static and dynamical. We show that, for a broad class of Gaussian systems, previously proposed PID formulas imply that (i) redundancy reduces to the minimum information provided by either source variable and hence is independent of correlation between sources, and (ii) synergy is the extra information contributed by the weaker source when the stronger source is known and can either increase or decrease with correlation between sources. We find that Gaussian systems frequently exhibit net synergy, i.e., the information carried jointly by both sources is greater than the sum of information carried by each source individually. Drawing from several explicit examples, we discuss the implications of these findings for measures of information transfer and information-based measures of complexity, both generally and within a neuroscience setting. Importantly, by providing independent formulas for synergy and redundancy applicable to continuous time-series data, we provide an approach to characterizing and quantifying information sharing amongst complex system variables. PMID:26066207

  7. TDAS: The Thermal Expert System (TEXSYS) data acquisition system

    NASA Technical Reports Server (NTRS)

    Hack, Edmund C.; Healey, Kathleen J.

    1987-01-01

    As part of the NASA Systems Autonomy Demonstration Project, a thermal expert system (TEXSYS) is being developed. TEXSYS combines a fast real time control system, a sophisticated human interface for the user and several distinct artificial intelligence techniques in one system. TEXSYS is to provide real time control, operations advice and fault detection, isolation and recovery capabilities for the space station Thermal Test Bed (TTB). TEXSYS will be integrated with the TTB and act as an intelligent assistant to thermal engineers conducting TTB tests and experiments. The results are presented from connecting the real time controller to the knowledge based system thereby creating an integrated system. Special attention will be paid to the problem of filtering and interpreting the raw, real time data and placing the important values into the knowledge base of the expert system.

  8. MOORE: A prototype expert system for diagnosing spacecraft problems

    NASA Technical Reports Server (NTRS)

    Howlin, Katherine; Weissert, Jerry; Krantz, Kerry

    1988-01-01

    MOORE is a rule-based, prototype expert system that assists in diagnosing operational Tracking and Data Relay Satellite (TDRS) problems. It is intended to assist spacecraft engineers at the TDRS ground terminal in trouble shooting problems that are not readily solved with routine procedures, and without expert counsel. An additional goal of the prototype system is to develop in-house expert system and knowledge engineering skills. The prototype system diagnoses antenna pointing and earth pointing problems that may occur within the TDRS Attitude Control System (ACS). Plans include expansion to fault isolation of problems in the most critical subsystems of the TDRS spacecraft. Long term benefits are anticipated with use of an expert system during future TDRS programs with increased mission support time, reduced problem solving time, and retained expert knowledge and experience. Phase 2 of the project is intended to provide NASA the necessary expertise and capability to define requirements, evaluate proposals, and monitor the development progress of a highly competent expert system for NASA's Tracking Data Relay Satellite. Phase 2 also envisions addressing two unexplored applications for expert systems, spacecraft integration and tests (I and T) and support to launch activities. The concept, goals, domain, tools, knowledge acquisition, developmental approach, and design of the expert system. It will explain how NASA obtained the knowledge and capability to develop the system in-house without assistance from outside consultants. Future plans will also be presented.

  9. System of Experts for Intelligent Data Management (SEIDAM)

    NASA Technical Reports Server (NTRS)

    Goodenough, David G.; Iisaka, Joji; Fung, KO

    1992-01-01

    It is proposed to conduct research and development on a system of expert systems for intelligent data management (SEIDAM). CCRS has much expertise in developing systems for integrating geographic information with space and aircraft remote sensing data and in managing large archives of remotely sensed data. SEIDAM will be composed of expert systems grouped in three levels. At the lowest level, the expert systems will manage and integrate data from diverse sources, taking account of symbolic representation differences and varying accuracies. Existing software can be controlled by these expert systems, without rewriting existing software into an Artificial Intelligence (AI) language. At the second level, SEIDAM will take the interpreted data (symbolic and numerical) and combine these with data models. At the top level, SEIDAM will respond to user goals for predictive outcomes given existing data. The SEIDAM Project will address the research areas of expert systems, data management, storage and retrieval, and user access and interfaces.

  10. System of experts for intelligent data management (SEIDAM)

    NASA Technical Reports Server (NTRS)

    Goodenough, David G.; Iisaka, Joji; Fung, KO

    1993-01-01

    A proposal to conduct research and development on a system of expert systems for intelligent data management (SEIDAM) is being developed. CCRS has much expertise in developing systems for integrating geographic information with space and aircraft remote sensing data and in managing large archives of remotely sensed data. SEIDAM will be composed of expert systems grouped in three levels. At the lowest level, the expert systems will manage and integrate data from diverse sources, taking account of symbolic representation differences and varying accuracies. Existing software can be controlled by these expert systems, without rewriting existing software into an Artificial Intelligence (AI) language. At the second level, SEIDAM will take the interpreted data (symbolic and numerical) and combine these with data models. at the top level, SEIDAM will respond to user goals for predictive outcomes given existing data. The SEIDAM Project will address the research areas of expert systems, data management, storage and retrieval, and user access and interfaces.

  11. A New Model for Redundancy Allocation Problem in Series Systems with Repairable Components by Genetic Algorithm

    NASA Astrophysics Data System (ADS)

    Sharifi, Mani; Rezaei Moayed, Reza; Haratizadeh, Sara

    2011-09-01

    This paper presents two models for redundancy allocation problem (RAP) with cold standby redundancy policy subject to weight and cost constraints. Also, each element of the system can be damaged exponentially. And, damaged elements can be repaired exponentially by hiring some repairmen. The problem is to determine: (1) element type used in the system, (2) number of elements, and (3) number of repairmen. As the models are not solvable by exact solution methods in reasonable CPU time, an efficient genetic algorithm is developed for it. The genetic algorithm (GA) is hybridized with a local search procedure. Also, the algorithm accepts infeasible solutions after penalizing them based on their amounts of infeasibilities. Thereby, by using these two features, an efficient genetic algorithm is obtained.

  12. Sensor failure detection and isolation in flexible structures using system realization redundancy

    NASA Astrophysics Data System (ADS)

    Zimmerman, David C.; Lyde, Terri L.

    1993-06-01

    Sensor failure detection and isolation for flexible structures is approached from a system realization perspective. Instead of using hardware or analytical model redundancy, system realization is utilized to provide an experimental based model redundancy. The failure detection and isolation algorithm utilizes the eigensystem realization algorithm to determine a minimum-order state-space realization of the structure in the presence of noisy measurements. The failure detection and isolation algorithm utilizes statistical comparisons of successive realizations to detect and isolate the failed sensor component. Because of the nature in which the failure detection and isolation algorithm is formulated, it is also possible to classify the failure mode of the sensor. Results are presented using both numerically simulated and actual experimental data.

  13. Asymmetric interjoint feedback contributes to postural control of redundant multi-link systems

    NASA Astrophysics Data System (ADS)

    Bunderson, Nathan E.; Ting, Lena H.; Burkholder, Thomas J.

    2007-09-01

    Maintaining the postural configuration of a limb such as an arm or leg is a fundamental neural control task that involves the coordination of multiple linked body segments. Biological systems are known to use a complex network of inter- and intra-joint feedback mechanisms arising from muscles, spinal reflexes and higher neuronal structures to stabilize the limbs. While previous work has shown that a small amount of asymmetric heterogenic feedback contributes to the behavior of these systems, a satisfactory functional explanation for this non-conservative feedback structure has not been put forth. We hypothesized that an asymmetric multi-joint control strategy would confer both an energetic and stability advantage in maintaining endpoint position of a kinematically redundant system. We tested this hypothesis by using optimal control models incorporating symmetric versus asymmetric feedback with the goal of maintaining the endpoint location of a kinematically redundant, planar limb. Asymmetric feedback improved endpoint control performance of the limb by 16%, reduced energetic cost by 21% and increased interjoint coordination by 40% compared to the symmetric feedback system. The overall effect of the asymmetry was that proximal joint motion resulted in greater torque generation at distal joints than vice versa. The asymmetric organization is consistent with heterogenic stretch reflex gains measured experimentally. We conclude that asymmetric feedback has a functionally relevant role in coordinating redundant degrees of freedom to maintain the position of the hand or foot.

  14. [Applications and progresses of expert system on chromatography].

    PubMed

    Xu, Guowang; Lu, Xin; Kong, Hongwei; Shi, Xianzhe; Zhao, Xinjie; Tian, Jing; Lu, Guo

    2005-09-01

    The expert system on chromatography has achieved great advancement in the past two decades, and is playing a more and more important role in solving analytical problems of complex samples. Research results of expert system on chromatography in authors' group are reviewed with 64 references. A brief introduction of the expert system on chromatography is presented. Applications of the expert system on chromatography are summarized in the fields of petrochemical online analysis, environmental air sample analysis, tumor diagnosis and traditional Chinese medicine analysis. The review followed the scientific foot steps in the authors' group, starting from the development of the expert system on gas chromatography, to the selection of multi-column systems in online industrial gas chromatographs in petrochemical plants, and to the employment of the new techniques in gas chromatography, liquid chromatography and capillary electrophoresis to solve the practical analytical problems in the nation's scientific and economic development. PMID:16350785

  15. Development of an expert system-based object tracking

    NASA Astrophysics Data System (ADS)

    Homainejad, Amir S.

    1998-12-01

    This paper outlines an experience of development of an expert system. The necessity of an expert system which can recognize and track any dynamic object in the field of view a vision system, was the main reason of development of the expert system. For achieving the goals of an expert system, some priorities must be considered. Dialogue is the first priority and it should be understandable by program. Otherwise, if a small error is given to computer, it will result in a large failure of knowledge and the wrong processing. Another priority is the knowledge-base, and this includes the procedural and the declarative memories. The paper will explain the application of above priority in a project of real time object tracking. The obtained results of tracking were compared with the results of surveying intersection so that the ability of the expert system was tested.

  16. A software engineering approach to expert system design and verification

    NASA Technical Reports Server (NTRS)

    Bochsler, Daniel C.; Goodwin, Mary Ann

    1988-01-01

    Software engineering design and verification methods for developing expert systems are not yet well defined. Integration of expert system technology into software production environments will require effective software engineering methodologies to support the entire life cycle of expert systems. The software engineering methods used to design and verify an expert system, RENEX, is discussed. RENEX demonstrates autonomous rendezvous and proximity operations, including replanning trajectory events and subsystem fault detection, onboard a space vehicle during flight. The RENEX designers utilized a number of software engineering methodologies to deal with the complex problems inherent in this system. An overview is presented of the methods utilized. Details of the verification process receive special emphasis. The benefits and weaknesses of the methods for supporting the development life cycle of expert systems are evaluated, and recommendations are made based on the overall experiences with the methods.

  17. Expert system verification and validation study

    NASA Technical Reports Server (NTRS)

    French, Scott W.; Hamilton, David

    1992-01-01

    Five workshops on verification and validation (V&V) of expert systems (ES) where taught during this recent period of performance. Two key activities, previously performed under this contract, supported these recent workshops (1) Survey of state-of-the-practice of V&V of ES and (2) Development of workshop material and first class. The first activity involved performing an extensive survey of ES developers in order to answer several questions regarding the state-of-the-practice in V&V of ES. These questions related to the amount and type of V&V done and the successfulness of this V&V. The next key activity involved developing an intensive hands-on workshop in V&V of ES. This activity involved surveying a large number of V&V techniques, conventional as well as ES specific ones. In addition to explaining the techniques, we showed how each technique could be applied on a sample problem. References were included in the workshop material, and cross referenced to techniques, so that students would know where to go to find additional information about each technique. In addition to teaching specific techniques, we included an extensive amount of material on V&V concepts and how to develop a V&V plan for an ES project. We felt this material was necessary so that developers would be prepared to develop an orderly and structured approach to V&V. That is, they would have a process that supported the use of the specific techniques. Finally, to provide hands-on experience, we developed a set of case study exercises. These exercises were to provide an opportunity for the students to apply all the material (concepts, techniques, and planning material) to a realistic problem.

  18. Toward the efficient implementation of expert systems in Ada

    NASA Technical Reports Server (NTRS)

    Lee, S. Daniel

    1990-01-01

    Here, the authors describe Ada language issues encountered during the development of ART-Ada, an expert system tool for Ada deployment. ART-Ada is being used to implement several expert system applications for the Space Station Freedom and the U.S. Air Force. Additional information is given on dynamic memory allocation.

  19. An Expert System Adviser for Tourists Planning To Visit Thailand.

    ERIC Educational Resources Information Center

    Kanchanosatha, Vinita

    This document reports on an examination of the analysis, design, development, implementation, and evaluation of an interactive computer program. The program is called an expert system adviser, and is for tourists planning on visiting Thailand. The expert system contains well-organized information that provides detailed coverage of Thailand. The…

  20. Cataloging and Expert Systems: AACR2 as a Knowledge Base.

    ERIC Educational Resources Information Center

    Hjerppe, Roland; Olander, Birgitta

    1989-01-01

    Describes a project that developed two expert systems for library cataloging using the second edition of the Anglo American Cataloging Rules (AACR2) as a knowledge base. The discussion covers cataloging as interpretation, the structure of AACR2, and the feasibility of using expert systems for cataloging in traditional library settings. (26…

  1. The Physics Tutor: Integrating Hypertext and Expert Systems.

    ERIC Educational Resources Information Center

    Jonassen, David H.; Wang, Sherwood

    1994-01-01

    Discussion of the development of intelligent tutoring systems (ITS) using expert systems and hypertext focuses on the Physics Tutor, a prototype ITS built with off-the-shelf software to test the utility, practicality, and generalizability of the ITS concept. Expert models and student models are explained. (Contains 27 references.) (LRW)

  2. An expert system for analyzing eddy current measurements

    SciTech Connect

    Levy, A.J.; Oppenlander, J.E.; Brudnoy, D.M.; Englund, J.M.; Loomis, K.C.

    1991-12-31

    A method and apparatus (called DODGER) analyzes eddy current data for heat exchanger tubes or any other metallic object. DODGER uses an expert system to analyze eddy current data by reasoning with uncertainty and pattern recognition. The expert system permits, DODGER to analyze eddy current data intelligently, an obviate operator uncertainty by analyzing the data in a uniform and consistent manner.

  3. The Principles of Designing an Expert System in Teaching Mathematics

    ERIC Educational Resources Information Center

    Salekhova, Lailya; Nurgaliev, Albert; Zaripova, Rinata; Khakimullina, Nailya

    2013-01-01

    This study reveals general didactic concepts of the Expert Systems (ES) development process in the educational area. The proof of concept is based on the example of teaching the 8th grade Algebra subject. The main contribution in this work is the implementation of innovative approaches in analysis and processing of data by expert system as well as…

  4. Introducing Expert Systems into the Business School Curriculum.

    ERIC Educational Resources Information Center

    Moen, David H.; And Others

    1992-01-01

    States that the usefulness of expert systems has caused them to become more popular in the work environment. Discusses how to incorporate material on expert system concepts into introductory courses in accounting and statistics at the undergraduate level and in quantitative analysis at the graduate level. (Author)

  5. Expert system for computer interpretation of beach and nearshore facies

    SciTech Connect

    Krystinik, K.B.; Clifton, H.E.

    1985-02-01

    A user-friendly, rule-based expert system has been designed for interpretation of lithofacies characteristics of beach and nearshore depositional environments. Recently, similar expert systems have been widely applied in medicine, business, and mineral exploration. The expert system runs on a VAX 780 (trade name). By incorporating knowledge and understanding of an expert, the system can interact with a user the way an expert consultant would. Interaction consists of a series of questions about lithology, sedimentary structures, and bioturbation of the lithofacies observed in outcrop or core. Uncertain responses are allowed and incorporated into the reasoning. Dialogue varies in different consultations because questions asked by the system depend on users' responses to previous questions. The result is an evaluation of the likelihood that the deposit under consideration is actually a beach or nearshore deposit. Significant lithofacies characteristics, the reasoning used in reaching the conclusion, and pertinent references are provided. Expert systems for other depositional environments are being designed. As their availability increases, geologists without easy access to experts on a particular depositional environment will have expert consultants as close as a computer terminal. Also the ability of the system to explain its reasoning and provide references lends the system to instructional uses.

  6. FUTURE OF EXPERT SYSTEMS IN THE ENVIRONMENTAL PROTECTION AGENCY

    EPA Science Inventory

    As in other organizations, the history of expert systems in the Environmental Protection Agency is very short. pproximately five years ago, the focus of our expert systems activities was to assess their feasibility and utility as environmental decision aids. ast year the Agency a...

  7. Expert systems applications for space shuttle payload integration automation

    NASA Technical Reports Server (NTRS)

    Morris, Keith

    1988-01-01

    Expert systems technologies have been and are continuing to be applied to NASA's Space Shuttle orbiter payload integration problems to provide a level of automation previously unrealizable. NASA's Space Shuttle orbiter was designed to be extremely flexible in its ability to accommodate many different types and combinations of satellites and experiments (payloads) within its payload bay. This flexibility results in differnet and unique engineering resource requirements for each of its payloads, creating recurring payload and cargo integration problems. Expert systems provide a successful solution for these recurring problems. The Orbiter Payload Bay Cabling Expert (EXCABL) was the first expert system, developed to solve the electrical services provisioning problem. A second expert system, EXMATCH, was developed to generate a list of the reusable installation drawings available for each EXCABL solution. These successes have proved the applicability of expert systems technologies to payload integration problems and consequently a third expert system is currently in work. These three expert systems, the manner in which they resolve payload problems and how they will be integrated are described.

  8. The potential of expert systems for remote sensing application

    NASA Technical Reports Server (NTRS)

    Mooneyhan, D. W.

    1983-01-01

    An overview of the status and potential of artificial intelligence-driven expert systems in the role of image data analysis is presented. An expert system is defined and its structure is summarized. Three such systems designed for image interpretation are outlined. The use of an expert system to detect changes on the earth's surface is discussed, and the components of a knowledge-based image interpretation system and their make-up are outlined. An example of how such a system should work for an area in the tropics where deforestation has occurred is presented as a sequence of situation/action decisions.

  9. Utilizing expert systems for satellite monitoring and control

    NASA Technical Reports Server (NTRS)

    Hughes, Peter M.

    1991-01-01

    Spacecraft analysts in the spacecraft control center for the Cosmic Background Explorer (COBE) satellite are currently utilizing a fault-isolation expert system developed to assist in the isolation and correction of faults in the communications link. This system, the communication link expert assistance resource (CLEAR), monitors real time spacecraft and ground systems performance parameters in search of configuration discrepancies and communications link problems. If such a discrepancy or problem is isolated, CLEAR alerts the analyst and provides advice on how to resolve the problem swiftly and effectively. The CLEAR system is the first real time expert system to be used in the operational environment of a satellite control center at the NASA Goddard Space Flight Center. Clear has not only demonstrated the utility and potential of an expert system in the demanding environment of a satellite control center, but also has revealed many of the pitfalls and deficiencies of development of expert systems. One of the lessons learned from this and other initial expert system projects is that prototypes can often be developed quite rapidly, but operational expert systems require considerable effort. Development is generally a slow, tedious process that typically requires the special skills of trained programmers. Due to the success of CLEAR and several other systems in the control center domain, a large number of expert systems will certainly be developed to support control center operations during the early 1990's. To facilitate the development of these systems, a project was initiated to develop an integrated, domain-specific tool, the generic spacecraft analyst assistent (GenSAA), that alows the spacecraft analysts to rapidly create simple expert systems themselves. By providing a highly graphical point-and-select method of system development, GenSAA allows the analyst to utilize and/or modify previously developed rule bases and system components; thus, facilitating

  10. Interfacing the expert: Characteristics and requirements for the user interface in expert systems

    NASA Technical Reports Server (NTRS)

    Potter, Andrew

    1987-01-01

    Because expert systems deal with new sets of problems presenting unique interface requirements, special issues requiring special attention are presented to user interface designers. External knowledge representation (how knowdedge is represented across the user interface), modes of user-system interdependence (advisory, cooperative, and autonomous), and management of uncertainty (deciding what actions to take or recommend based on incomplete evidence) are discussed.

  11. SCARES: A Spacecraft Control Anomaly Resolution Expert System

    NASA Technical Reports Server (NTRS)

    Hamilton, Marc

    1988-01-01

    The current pace of technological development is reflected in the increased mission lifetime of each new generation of satellite. Coupled with this has come a reduced availability of experts to provide technical assistance in satellite operation on a day to day basis. Given such an environment, an expert system is discussed based on architecture for spacecraft anomaly resolution. By capturing deep knowledge about a spacecraft, the system is able to detect and diagnose fault better than previous conventional approaches. A prototype expert system named SCARES (applied only to spacecraft attitude control system) is discussed. Extension of the prototype to handle anomalies in other systems of the satellite is also discussed.

  12. Inter-computer communication architecture for a mixed redundancy distributed system

    NASA Technical Reports Server (NTRS)

    Lala, Jaynarayan H.; Adams, Stuart J.

    1987-01-01

    The triply redundant intercomputer network for the Advanced Information Processing System (AIPS), an architecture developed to serve as the core avionics system for a broad range of aerospace vehicles, is discussed. The AIPS intercomputer network provides a high-speed, Byzantine-fault-resilient communication service between processing sites, even in the presence of arbitrary failures of simplex and duplex processing sites on the IC network. The IC network contention poll has evolved from the Laning Poll. An analysis of the failure modes and effects and a simulation of the AIPS contention poll, demonstrate the robustness of the system.

  13. Early Warning Expert System for Equipment Operability Surveillance

    Energy Science and Technology Software Center (ESTSC)

    1996-12-18

    EWES is an Al-based expert system for signal validation and sensor operability surveillance in industrial applications that require high-reliability, high-sensitivity annunciation of degraded sensors, discrepant signals, or the onset or incipience of system disturbances.

  14. An expert system for reliability modeling

    NASA Technical Reports Server (NTRS)

    Goss, Ernst; Sundaraiyer, Vani; Whitten, Alan

    1988-01-01

    A method is presented for computing the probability of failure of a unit during the next usage or mission based on sound statistical techniques. With the use of logit regression embedded in Lotus 1-2-3 macros, this package computes the probability of unit failure based upon a historical data base. Using this computed probability of failure, the package then makes a replacement recommendation based upon the experts acceptable risk parameters.

  15. Class 2: An Expert System for Student Classification. Technical Paper.

    ERIC Educational Resources Information Center

    Ferrara, Joseph M.; And Others

    The paper describes an approach to developing systematic procedures for identifying handicapped children that leads to rational decisions regarding placement. An expert system is described which involves the user in a dialogue on data regarding individual children; this dialogue is similar in many ways to a consultation with an expert. After…

  16. Tools and technologies for expert systems: A human factors perspective

    NASA Technical Reports Server (NTRS)

    Rajaram, Navaratna S.

    1987-01-01

    It is widely recognized that technologies based on artificial intelligence (AI), especially expert systems, can make significant contributions to the productivity and effectiveness of operations of information and knowledge intensive organizations such as NASA. At the same time, these being relatively new technologies, there is the problem of transfering technology to key personnel of such organizations. The problems of examining the potential of expert systems and of technology transfer is addressed in the context of human factors applications. One of the topics of interest was the investigation of the potential use of expert system building tools, particularly NEXPERT as a technology transfer medium. Two basic conclusions were reached in this regard. First, NEXPERT is an excellent tool for rapid prototyping of experimental expert systems, but not ideal as a delivery vehicle. Therefore, it is not a substitute for general purpose system implementation languages such a LISP or C. This assertion probably holds for nearly all such tools on the market today. Second, an effective technology transfer mechanism is to formulate and implement expert systems for problems which members of the organization in question can relate to. For this purpose, the LIghting EnGineering Expert (LIEGE) was implemented using NEXPERT as the tool for technology transfer and to illustrate the value of expert systems to the activities of the Man-System Division.

  17. Expert System For Diagnosis Pest And Disease In Fruit Plants

    NASA Astrophysics Data System (ADS)

    Dewanto, Satrio; Lukas, Jonathan

    2014-03-01

    This paper discussed the development of an expert system to diagnose pests and diseases on fruit plants. Rule base method was used to store the knowledge from experts and literatures. Control technique using backward chain and started from the symptoms to get conclusions about the pests and diseases that occur. Development of the system has been performed using software Corvid Exsys developed by Exsys company. Results showed that the development of this expert system can be used to assist users in identifying the type of pests and diseases on fruit plants. Further development and possibility of using internet for this system are proposed.

  18. An Expert System for the Development of Efficient Parallel Code

    NASA Technical Reports Server (NTRS)

    Jost, Gabriele; Chun, Robert; Jin, Hao-Qiang; Labarta, Jesus; Gimenez, Judit

    2004-01-01

    We have built the prototype of an expert system to assist the user in the development of efficient parallel code. The system was integrated into the parallel programming environment that is currently being developed at NASA Ames. The expert system interfaces to tools for automatic parallelization and performance analysis. It uses static program structure information and performance data in order to automatically determine causes of poor performance and to make suggestions for improvements. In this paper we give an overview of our programming environment, describe the prototype implementation of our expert system, and demonstrate its usefulness with several case studies.

  19. Styles Of Programming In Neural Networks And Expert Systems

    NASA Astrophysics Data System (ADS)

    Duda, Richard O.

    1989-03-01

    Neural networks and expert systems provide different ways to reduce the programming effort required to build complex systems. Adaptive neural networks are programmed merely by training them with examples. Rule-based expert system are developed incrementally merely by adding rules. Although neural networks seem best suited for low-level sensory processing and expert systems seem best suited for high-level symbolic processing, strikingly similar issues arise when these approaches are used in large-scale applications. Illustrative examples of such applications are presented and discussed.

  20. An expert system based intelligent control scheme for space bioreactors

    NASA Technical Reports Server (NTRS)

    San, Ka-Yiu

    1988-01-01

    An expert system based intelligent control scheme is being developed for the effective control and full automation of bioreactor systems in space. The scheme developed will have the capability to capture information from various resources including heuristic information from process researchers and operators. The knowledge base of the expert system should contain enough expertise to perform on-line system identification and thus be able to adapt the controllers accordingly with minimal human supervision.

  1. An expert system for shuttle and satellite radar tracker scheduling

    NASA Technical Reports Server (NTRS)

    Mitchell, Paul

    1988-01-01

    This expert system automates and optimizes radar tracker selection for shuttle missions. The expert system is written in the FORTRAN and C languages on an HP9000. It is portable to any UNIX machine having both ANSI-77 FORTRAN and C language compilers. It is a rule based expert system that selects tracking stations from the S-band and C-band radar stations and the TDRSS east and TDRSS west satellites under a variety of conditions. The expert system was prototyped on the Symbolics in the Automated Reasoning Tool (ART) and ZetaLisp. After the prototype demonstrated an acceptable automation of the process of selecting tracking stations to support the orbit determination requirements of Shuttle missions, the basic ART rules of the prototype were ported to the HP9000 computer using the CLIPS language. CLIPS is a forward-chaining rule-based expert system language written in C. Prior to the development of this expert system the selection process was a tedious manual process and expensive in terms of human resources. Manual tracking station selection required from 1 to 2 man weeks per mission; whereas the expert system can complete the selection process in about 2 hours.

  2. Prediction of low back pain with two expert systems.

    PubMed

    Sari, Murat; Gulbandilar, Eyyup; Cimbiz, Ali

    2012-06-01

    Low back pain (LBP) is one of the common problems encountered in medical applications. This paper proposes two expert systems (artificial neural network and adaptive neuro-fuzzy inference system) for the assessment of the LBP level objectively. The skin resistance and visual analog scale (VAS) values have been accepted as the input variables for the developed systems. The results showed that the expert systems behave very similar to real data and that use of the expert systems can be used to successfully diagnose the back pain intensity. The suggested systems were found to be advantageous approaches in addition to existing unbiased approaches. So far as the authors are aware, this is the first attempt of using the two expert systems achieving very good performance in a real application. In light of some of the limitations of this study, we also identify and discuss several areas that need continued investigation. PMID:20978929

  3. Howling canceling for high gain speakerphone systems exploiting the loudspeaker redundancy

    NASA Astrophysics Data System (ADS)

    Zhang, Jingjing; Yin, Qinye; Mu, Pengcheng; Song, Tianheng; Wang, Wei; Wu, Junchao

    2011-10-01

    Howling of an audio amplifying system is annoying, which may occur when a closed-loop is formed for amplified signals. In this paper, we exploit the space diversity offered by the loudspeaker redundancy and develop a new howling canceling approach for high gain speakerphone systems. The amplified waves are weighted at the two loudspeakers to achieve self-cancellation at the microphone after the propagation. As a result, the echo waves can be completely eliminated at the microphone, which avoids any feedback that yields the howling. Results of simulation and hardware test show effectiveness of the method.

  4. Control of a teleoperator system with redundancy based on passivity conditions

    SciTech Connect

    Jansen, J.F.; Kress, R.L.

    1991-01-01

    The purpose of this paper is to examine how a stiffness controller can be used to control a teleoperator system having a redundant degree-of-freedom (dof) slave manipulator and a dissimilar master. No path planning was allowed because the uncertainty of the environment and computational limitations. The proposed controller was implemented on the 7-dof Center for Engineering Systems Advanced Research Manipulator (CESARm) slave manipulator with a 6-dof Kraft master manipulator. The overall performance of this scheme and future directions are discussed. 21 refs., 3 figs.

  5. Expert systems for space power supply - Design, analysis, and evaluation

    NASA Technical Reports Server (NTRS)

    Cooper, Ralph S.; Thomson, M. Kemer; Hoshor, Alan

    1987-01-01

    The feasibility of applying expert systems to the conceptual design, analysis, and evaluation of space power supplies in particular, and complex systems in general is evaluated. To do this, the space power supply design process and its associated knowledge base were analyzed and characterized in a form suitable for computer emulation of a human expert. The existing expert system tools and the results achieved with them were evaluated to assess their applicability to power system design. Some new concepts for combining program architectures (modular expert systems and algorithms) with information about the domain were applied to create a 'deep' system for handling the complex design problem. NOVICE, a code to solve a simplified version of a scoping study of a wide variety of power supply types for a broad range of missions, has been developed, programmed, and tested as a concrete feasibility demonstration.

  6. Development of a Spacecraft Materials Selector Expert System

    NASA Technical Reports Server (NTRS)

    Pippin, G.; Kauffman, W. (Technical Monitor)

    2002-01-01

    This report contains a description of the knowledge base tool and examples of its use. A downloadable version of the Spacecraft Materials Selector (SMS) knowledge base is available through the NASA Space Environments and Effects Program. The "Spacecraft Materials Selector" knowledge base is part of an electronic expert system. The expert system consists of an inference engine that contains the "decision-making" code and the knowledge base that contains the selected body of information. The inference engine is a software package previously developed at Boeing, called the Boeing Expert System Tool (BEST) kit.

  7. Expert systems identify fossils and manage large paleontological databases

    SciTech Connect

    Beightol, D.S. ); Conrad, M.A.

    1988-02-01

    EXPAL is a computer program permitting creation and maintenance of comprehensive databases in marine paleontology. It is designed to assist specialists and non-specialists. EXPAL includes a powerful expert system based on the morphological descriptors specific to a given group of fossils. The expert system may be used, for example, to describe and automatically identify an unknown specimen. EXPAL was first applied to Dasycladales (Calcareous green algae). Projects are under way for corresponding expert systems and databases on planktonic foraminifers and calpionellids. EXPAL runs on an IBM XT or compatible microcomputer.

  8. Verification issues for rule-based expert systems

    NASA Technical Reports Server (NTRS)

    Culbert, Chris; Riley, Gary; Savely, Robert T.

    1987-01-01

    Verification and validation of expert systems is very important for the future success of this technology. Software will never be used in non-trivial applications unless the program developers can assure both users and managers that the software is reliable and generally free from error. Therefore, verification and validation of expert systems must be done. The primary hindrance to effective verification and validation is the use of methodologies which do not produce testable requirements. An extension of the flight technique panels used in previous NASA programs should provide both documented requirements and very high levels of verification for expert systems.

  9. Toward an expert project management system

    NASA Technical Reports Server (NTRS)

    Silverman, Barry G.; Murray, Arthur; Diakite, Coty; Feggos, Kostas

    1987-01-01

    The purpose of the research effort is to prescribe a generic reusable shell that any project office can install and customize for the purposes of advising, guiding, and supporting project managers in that office. The prescribed shell is intended to provide both: a component that generates prescriptive guidance for project planning and monitoring activities, and an analogy (intuition) component that generates descriptive insights of previous experience of successful project managers. The latter component is especially significant in that it has the potential to: retrieve insights, not just data, and provide a vehicle for expert PMs to easily transcribe their current experiences in the course of each new project managed.

  10. An Embedded Rule-Based Diagnostic Expert System in Ada

    NASA Technical Reports Server (NTRS)

    Jones, Robert E.; Liberman, Eugene M.

    1992-01-01

    Ada is becoming an increasingly popular programming language for large Government-funded software projects. Ada with it portability, transportability, and maintainability lends itself well to today's complex programming environment. In addition, expert systems have also assumed a growing role in providing human-like reasoning capability expertise for computer systems. The integration is discussed of expert system technology with Ada programming language, especially a rule-based expert system using an ART-Ada (Automated Reasoning Tool for Ada) system shell. NASA Lewis was chosen as a beta test site for ART-Ada. The test was conducted by implementing the existing Autonomous Power EXpert System (APEX), a Lisp-based power expert system, in ART-Ada. Three components, the rule-based expert systems, a graphics user interface, and communications software make up SMART-Ada (Systems fault Management with ART-Ada). The rules were written in the ART-Ada development environment and converted to Ada source code. The graphics interface was developed with the Transportable Application Environment (TAE) Plus, which generates Ada source code to control graphics images. SMART-Ada communicates with a remote host to obtain either simulated or real data. The Ada source code generated with ART-Ada, TAE Plus, and communications code was incorporated into an Ada expert system that reads the data from a power distribution test bed, applies the rule to determine a fault, if one exists, and graphically displays it on the screen. The main objective, to conduct a beta test on the ART-Ada rule-based expert system shell, was achieved. The system is operational. New Ada tools will assist in future successful projects. ART-Ada is one such tool and is a viable alternative to the straight Ada code when an application requires a rule-based or knowledge-based approach.

  11. Object-oriented knowledge representation for expert systems

    NASA Technical Reports Server (NTRS)

    Scott, Stephen L.

    1991-01-01

    Object oriented techniques have generated considerable interest in the Artificial Intelligence (AI) community in recent years. This paper discusses an approach for representing expert system knowledge using classes, objects, and message passing. The implementation is in version 4.3 of NASA's C Language Integrated Production System (CLIPS), an expert system tool that does not provide direct support for object oriented design. The method uses programmer imposed conventions and keywords to structure facts, and rules to provide object oriented capabilities.

  12. An expert system to facilitate selecting a database management system

    SciTech Connect

    Roseberry, L.M.; Kilgore, D.C.

    1989-06-06

    An investigation has been initiated to develop an expert system to assist information professionals in selecting a database management system (DBMS). The system attempts to consider DBMS basic design, theory, and performance standard as well as the specific needs of the project. The user is queried for needs, wants, and resource restrictions. The inference engine tests these data against its rule set and generates prioritized recommendations. The rule set design will be discussed. The usefulness of such a tool will be discussed as well as plans for its continued evolution.

  13. Expert system for controlling plant growth in a contained environment

    NASA Technical Reports Server (NTRS)

    May, George A. (Inventor); Lanoue, Mark Allen (Inventor); Bethel, Matthew (Inventor); Ryan, Robert E. (Inventor)

    2011-01-01

    In a system for optimizing crop growth, vegetation is cultivated in a contained environment, such as a greenhouse, an underground cavern or other enclosed space. Imaging equipment is positioned within or about the contained environment, to acquire spatially distributed crop growth information, and environmental sensors are provided to acquire data regarding multiple environmental conditions that can affect crop development. Illumination within the contained environment, and the addition of essential nutrients and chemicals are in turn controlled in response to data acquired by the imaging apparatus and environmental sensors, by an "expert system" which is trained to analyze and evaluate crop conditions. The expert system controls the spatial and temporal lighting pattern within the contained area, and the timing and allocation of nutrients and chemicals to achieve optimized crop development. A user can access the "expert system" remotely, to assess activity within the growth chamber, and can override the "expert system".

  14. Expert system for controlling plant growth in a contained environment

    NASA Technical Reports Server (NTRS)

    May, George A. (Inventor); Lanoue, Mark Allen (Inventor); Bethel, Matthew (Inventor); Ryan, Robert E. (Inventor)

    2009-01-01

    In a system for optimizing crop growth, vegetation is cultivated in a contained environment, such as a greenhouse, an underground cavern or other enclosed space. Imaging equipment is positioned within or about the contained environment, to acquire spatially distributed crop growth information, and environmental sensors are provided to acquire data regarding multiple environmental conditions that can affect crop development. Illumination within the contained environment, and the addition of essential nutrients and chemicals are in turn controlled in response to data acquired by the imaging apparatus and environmental sensors, by an ''expert system'' which is trained to analyze and evaluate crop conditions. The expert system controls the spatial and temporal lighting pattern within the contained area, and the timing and allocation of nutrients and chemicals to achieve optimized crop development. A user can access the ''expert system'' remotely, to assess activity within the growth chamber, and can override the ''expert system''.

  15. ATS displays: A reasoning visualization tool for expert systems

    NASA Technical Reports Server (NTRS)

    Selig, William John; Johannes, James D.

    1990-01-01

    Reasoning visualization is a useful tool that can help users better understand the inherently non-sequential logic of an expert system. While this is desirable in most all expert system applications, it is especially so for such critical systems as those destined for space-based operations. A hierarchical view of the expert system reasoning process and some characteristics of these various levels is presented. Also presented are Abstract Time Slice (ATS) displays, a tool to visualize the plethora of interrelated information available at the host inferencing language level of reasoning. The usefulness of this tool is illustrated with some examples from a prototype potable water expert system for possible use aboard Space Station Freedom.

  16. Parallelism in backward-chained expert systems - Experimental results

    NASA Technical Reports Server (NTRS)

    Hall, Lawrence O.

    1990-01-01

    There are many applications which may be done by an expert system in real time, if the system is capable of real-time response. The LISP and PROLOG-based expert systems have typically been too slow for real-time response. This has led to an effort to use other languages, the development of fast pattern matching techniques and other methods of improving the speed of expert systems. Another approach to developing faster expert systems is to make use of the emerging parallel processing computer technology. A further use for parallelism is to allow reasonable response time for large knowledge bases. The size of knowledge bases may become as large as 20,000 chunks of knowledge (and more) in the near future in medical and space applications. This paper describes the use of parallel processing in the EMYCIN backward chained rule-based model.

  17. Comparative analysis of profit between three dissimilar repairable redundant systems using supporting external device for operation

    NASA Astrophysics Data System (ADS)

    Yusuf, Ibrahim

    2014-07-01

    The importance in promoting, sustaining industries, manufacturing systems and economy through reliability measurement has become an area of interest. The profit of a system may be enhanced using highly reliable structural design of the system or subsystem of higher reliability. On improving the reliability and availability of a system, the production and associated profit will also increase. Reliability, availability and profit are some of the most important factors in any successful industry and manufacturing settings. In this paper, we compare three different repairable redundant systems using an external supporting device for operation based on the profit. Explicit expressions for the busy period of repairmen, steady-state availability and profit function are derived using linear first-order differential equations. Furthermore, we compare the profit for the three systems and find that system I is more profitable than systems II and III.

  18. Multiple neural network approaches to clinical expert systems

    NASA Astrophysics Data System (ADS)

    Stubbs, Derek F.

    1990-08-01

    We briefly review the concept of computer aided medical diagnosis and more extensively review the the existing literature on neural network applications in the field. Neural networks can function as simple expert systems for diagnosis or prognosis. Using a public database we develop a neural network for the diagnosis of a major presenting symptom while discussing the development process and possible approaches. MEDICAL EXPERTS SYSTEMS COMPUTER AIDED DIAGNOSIS Biomedicine is an incredibly diverse and multidisciplinary field and it is not surprising that neural networks with their many applications are finding more and more applications in the highly non-linear field of biomedicine. I want to concentrate on neural networks as medical expert systems for clinical diagnosis or prognosis. Expert Systems started out as a set of computerized " ifthen" rules. Everything was reduced to boolean logic and the promised land of computer experts was said to be in sight. It never came. Why? First the computer code explodes as the number of " ifs" increases. All the " ifs" have to interact. Second experts are not very good at reducing expertise to language. It turns out that experts recognize patterns and have non-verbal left-brain intuition decision processes. Third learning by example rather than learning by rule is the way natural brains works and making computers work by rule-learning is hideously labor intensive. Neural networks can learn from example. They learn the results

  19. The need for a comprehensive expert system development methodology

    NASA Technical Reports Server (NTRS)

    Baumert, John; Critchfield, Anna; Leavitt, Karen

    1988-01-01

    In a traditional software development environment, the introduction of standardized approaches has led to higher quality, maintainable products on the technical side and greater visibility into the status of the effort on the management side. This study examined expert system development to determine whether it differed enough from traditional systems to warrant a reevaluation of current software development methodologies. Its purpose was to identify areas of similarity with traditional software development and areas requiring tailoring to the unique needs of expert systems. A second purpose was to determine whether existing expert system development methodologies meet the needs of expert system development, management, and maintenance personnel. The study consisted of a literature search and personal interviews. It was determined that existing methodologies and approaches to developing expert systems are not comprehensive nor are they easily applied, especially to cradle to grave system development. As a result, requirements were derived for an expert system development methodology and an initial annotated outline derived for such a methodology.

  20. Need for a comprehensive expert system development methodology

    SciTech Connect

    Baumert, J.; Critchfield, A.; Leavitt, K.

    1988-01-01

    In a traditional software development environment, the introduction of standardized approaches has led to higher quality, maintainable products on the technical side and greater visibility into the status of the effort on the management side. This study examined expert system development to determine whether it differed enough from traditional systems to warrant a reevaluation of current software development methodologies. Its purpose was to identify areas of similarity with traditional software development and areas requiring tailoring to the unique needs of expert systems. A second purpose was to determine whether existing expert system development methodologies meet the needs of expert system development, management, and maintenance personnel. The study consisted of a literature search and personal interviews. It was determined that existing methodologies and approaches to developing expert systems are not comprehensive nor are they easily applied, especially to cradle to grave system development. As a result, requirements were derived for an expert system development methodology and an initial annotated outline derived for such a methodology. 9 references.

  1. Strategies for redundancy resolution of dual-arm systems with passive elements for tank waste removal

    SciTech Connect

    Dubey, R.; Love, L.J.

    1997-03-01

    The work described in this paper focuses on the coordination and control of two manipulators coupled by passive elements operating in a confined space. An example of one such system is the hardware used for the environmental response treatability study funded by the Department of Energy at Oak Ridge National Laboratory (ORNL). The motivation for this project is to establish the methodology necessary to extract large volumes of hazardous waste from underground storage facilities. The hardware used at ORNL consists of two long-reach manipulators. The first robot, the Modified Light Duty Utility Arm (MLDUA), is an 8-degree-of-freedom long-reach manipulator. The second arm, the Hose Management Arm (HMA), has two active degrees-of-freedom and provides hardware to break up and extract materials from the tank. Current strategies call for the MLDUA to grasp a combined sluicing end-effector attached, by a long flexible hose, to the HMA. The MLDUA will then move the combined system through the waste, extracting material. This paper describes many of the issues related to redundancy resolution and the coordinated control of these two robots. First, the authors provide a brief outline of the project and the existing hardware. This is followed by a description of existing redundancy resolution techniques and the impact redundancy has on the success of the project. Finally, preliminary simulation results show the effect cooperative control has on the level of forces generated between the dual-arm systems when coupled by an elastic exhaust hose. These results show a significant reduction in forces when both arms are active and have a combined manipulation strategy.

  2. A middle man approach to knowledge acquisition in expert systems

    NASA Technical Reports Server (NTRS)

    Jordan, Janice A.; Lin, Min-Jin; Mayer, Richard J.; Sterle, Mark E.

    1990-01-01

    The Weed Control Advisor (WCA) is a robust expert system that has been successfully implemented on an IBM AT class microcomputer in CLIPS. The goal of the WCA was to demonstrate the feasibility of providing an economical, efficient, user friendly system through which Texas rice producers could obtain expert level knowledge regarding herbicide application for weed control. During the development phase of the WCA, an improved knowledge acquisition method which we call the Middle Man Approach (MMA) was applied to facilitate the communication process between the domain experts and the knowledge engineer. The MMA served to circumvent the problems associated with the more traditional forms of knowledge acquisition by placing the Middle Man, a semi-expert in the problem domain with some computer expertise, at the site of system development. The middle man was able to contribute to system development in two major ways. First, the Middle Man had experience working in rice production and could assume many of the responsibilities normally performed by the domain experts such as explaining the background of the problem domain and determining the important relations. Second, the Middle Man was familiar with computers and worked closely with the system developers to update the rules after the domain experts reviewed the prototype, contribute to the help menus and explanation portions of the expert system, conduct the testing that is required to insure that the expert system gives the expected results answer questions in a timely way, help the knowledge engineer structure the domain knowledge into a useable form, and provide insight into the end user's profile which helped in the development of the simple user friendly interface. The final results were not only that both time expended and costs were greatly reduced by using the MMA, but the quality of the system was improved. This papa will introduce the WCA system and then discuss traditional knowledge acquisition along with

  3. A nonlinear singular eigenvalue problem for a linear system of ordinary differential equations with redundant conditions

    NASA Astrophysics Data System (ADS)

    Abramov, A. A.; Yukhno, L. F.

    2016-07-01

    A nonlinear eigenvalue problem for a linear system of ordinary differential equations is examined on a semi-infinite interval. The problem is supplemented by nonlocal conditions specified by a Stieltjes integral. At infinity, the solution must be bounded. In addition to these basic conditions, the solution must satisfy certain redundant conditions, which are also nonlocal. A numerically stable method for solving such a singular overdetermined eigenvalue problem is proposed and analyzed. The essence of the method is that this overdetermined problem is replaced by an auxiliary problem consistent with all the above conditions.

  4. SIDES - Segment Interconnect Diagnostic Expert System

    SciTech Connect

    Booth, A.W.; Forster, R.; Gustafsson, L.; Ho, N.

    1989-02-01

    It is well known that the FASTBUS Segment Interconnect (SI) provides a communication path between two otherwise independent, asynchronous bus segments. The SI is probably the most important module in any FASTBUS data acquisition network since it's failure to function can cause whole segments of the network to be inaccessible and sometimes inoperable. This paper describes SIDES, an intelligent program designed to diagnose SI's both in situ as they operate in a data acquisition network, and in the laboratory in an acceptance/repair environment. The paper discusses important issues such as knowledge acquisition; extracting knowledge from human experts and other knowledge sources. SIDES can benefit high energy physics experiments, where SI problems can be diagnosed and solved more quickly. Equipment pool technicians can also benefit from SIDES, first by decreasing the number of SI's erroneously turned in for repair, and secondly as SIDES acts as an intelligent assistant to the technician in the diagnosis and repair process.

  5. Advanced Launch System Multi-Path Redundant Avionics Architecture Analysis and Characterization

    NASA Technical Reports Server (NTRS)

    Baker, Robert L.

    1993-01-01

    The objective of the Multi-Path Redundant Avionics Suite (MPRAS) program is the development of a set of avionic architectural modules which will be applicable to the family of launch vehicles required to support the Advanced Launch System (ALS). To enable ALS cost/performance requirements to be met, the MPRAS must support autonomy, maintenance, and testability capabilities which exceed those present in conventional launch vehicles. The multi-path redundant or fault tolerance characteristics of the MPRAS are necessary to offset a reduction in avionics reliability due to the increased complexity needed to support these new cost reduction and performance capabilities and to meet avionics reliability requirements which will provide cost-effective reductions in overall ALS recurring costs. A complex, real-time distributed computing system is needed to meet the ALS avionics system requirements. General Dynamics, Boeing Aerospace, and C.S. Draper Laboratory have proposed system architectures as candidates for the ALS MPRAS. The purpose of this document is to report the results of independent performance and reliability characterization and assessment analyses of each proposed candidate architecture and qualitative assessments of testability, maintainability, and fault tolerance mechanisms. These independent analyses were conducted as part of the MPRAS Part 2 program and were carried under NASA Langley Research Contract NAS1-17964, Task Assignment 28.

  6. Integrated Hypertext and Expert System in Pathology Laboratory Instruction

    PubMed Central

    Sideli, Robert V.; Lefkowitch, Jay L.

    1988-01-01

    Computer lab exercises in Pathology are described which implement both hypertext and an expert system. The lab exercises served as prototypes which were used to study various aspects of computers in medical education. The software utilized was either found in the public domain or purchased from a vendor. Minor programming modifications allowed the hypertext program and expert system to form an integrated learning environment. Favorable student response and readily accessible programming tools suggest that further work will be educationally valuable.

  7. NASA ground terminal communication equipment automated fault isolation expert systems

    NASA Technical Reports Server (NTRS)

    Tang, Y. K.; Wetzel, C. R.

    1990-01-01

    The prototype expert systems are described that diagnose the Distribution and Switching System I and II (DSS1 and DSS2), Statistical Multiplexers (SM), and Multiplexer and Demultiplexer systems (MDM) at the NASA Ground Terminal (NGT). A system level fault isolation expert system monitors the activities of a selected data stream, verifies that the fault exists in the NGT and identifies the faulty equipment. Equipment level fault isolation expert systems are invoked to isolate the fault to a Line Replaceable Unit (LRU) level. Input and sometimes output data stream activities for the equipment are available. The system level fault isolation expert system compares the equipment input and output status for a data stream and performs loopback tests (if necessary) to isolate the faulty equipment. The equipment level fault isolation system utilizes the process of elimination and/or the maintenance personnel's fault isolation experience stored in its knowledge base. The DSS1, DSS2 and SM fault isolation systems, using the knowledge of the current equipment configuration and the equipment circuitry issues a set of test connections according to the predefined rules. The faulty component or board can be identified by the expert system by analyzing the test results. The MDM fault isolation system correlates the failure symptoms with the faulty component based on maintenance personnel experience. The faulty component can be determined by knowing the failure symptoms. The DSS1, DSS2, SM, and MDM equipment simulators are implemented in PASCAL. The DSS1 fault isolation expert system was converted to C language from VP-Expert and integrated into the NGT automation software for offline switch diagnoses. Potentially, the NGT fault isolation algorithms can be used for the DSS1, SM, amd MDM located at Goddard Space Flight Center (GSFC).

  8. Application of combined controller based on CMAC and nonlinear PID in dual redundant telescope tracking system

    NASA Astrophysics Data System (ADS)

    Li, Heng; Ren, Changzhi; Song, Libin; Wu, Jun

    2014-07-01

    The direct drive tracking system of Telescope is one multivariable, nonlinear and strong coupling complex mechanical control system which is disturbed by some nonlinear disturbance such torque ripple, wind disturbance during the tracking process. the traditional PID control cannot fundamentally solved the contradiction between static and dynamic performance, tracking data and disturbance .This paper explores a kind of CMAC with nonlinear PID parallel composite control method for dual redundant telescope tracing servo system. The simulation result proves that combined algorithm based on CMAC and PID realizes the servo system without overshoot and accelerates the response of the system. What's more, CMAC feedforward control improves anti-disturbance ability and the control precision of the servo system.

  9. Systematic methods for knowledge acquisition and expert system development

    NASA Technical Reports Server (NTRS)

    Belkin, Brenda L.; Stengel, Robert F.

    1991-01-01

    Nine cooperating rule-based systems, collectively called AUTOCREW, were designed to automate functions and decisions associated with a combat aircraft's subsystem. The organization of tasks within each system is described; performance metrics were developed to evaluate the workload of each rule base, and to assess the cooperation between the rule-bases. Each AUTOCREW subsystem is composed of several expert systems that perform specific tasks. AUTOCREW's NAVIGATOR was analyzed in detail to understand the difficulties involved in designing the system and to identify tools and methodologies that ease development. The NAVIGATOR determines optimal navigation strategies from a set of available sensors. A Navigation Sensor Management (NSM) expert system was systematically designed from Kalman filter covariance data; four ground-based, a satellite-based, and two on-board INS-aiding sensors were modeled and simulated to aid an INS. The NSM Expert was developed using the Analysis of Variance (ANOVA) and the ID3 algorithm. Navigation strategy selection is based on an RSS position error decision metric, which is computed from the covariance data. Results show that the NSM Expert predicts position error correctly between 45 and 100 percent of the time for a specified navaid configuration and aircraft trajectory. The NSM Expert adapts to new situations, and provides reasonable estimates of hybrid performance. The systematic nature of the ANOVA/ID3 method makes it broadly applicable to expert system design when experimental or simulation data is available.

  10. Learning to live independently with expert systems in memory rehabilitation.

    PubMed

    Man, D W K; Tam, S F; Hui-Chan, C W Y

    2003-01-01

    Expert systems (ES), which are a branch of artificial intelligence, has been widely used in different applications, including medical consultation and more recently in rehabilitation for assessment and intervention. The development and validation of an expert system for memory rehabilitation (ES-MR) is reported here. Through a web-based platform, ES-MR can provide experts with better decision making in providing intervention for persons with brain injuries, stroke, and dementia. The application and possible commercial production of a simultaneously developed version for "non-expert" users is proposed. This is especially useful for providing remote assistance to persons with permanent memory impairment when they reach a plateau of cognitive training and demand a prosthetic system to enhance memory for day-to-day independence. The potential use of ES-MR as a cognitive aid in conjunction with WAP mobile phones, Bluetooth technology, and Personal Digital Assistants (PDAs) is suggested as an avenue for future study. PMID:12719618

  11. Explanations in knowledge systems - Design for Explainable Expert Systems

    NASA Technical Reports Server (NTRS)

    Swartout, William; Paris, Cecile; Moore, Johanna

    1991-01-01

    The Explainable Expert Systems framework (EES), in which the focus is on capturing those design aspects that are important for producing good explanations, including justifications of the system's actions, explications of general problem-solving strategies, and descriptions of the system's terminology, is discussed. EES was developed as part of the Strategic Computing Initiative of DARPA. Both the general principles from which the system was derived and how the system was derived from those principles can be represented in EES. The Program Enhancement Advisor, which is the main prototype on which the explanation work has been developed and tested, is presented. PEA is an advice system that helps users improve their Common Lisp programs by recommending transformations that enhance the user's code. How EES produces better explanations is shown.

  12. Application of an expert system in the management of HIV-infected patients.

    PubMed

    Pazzani, M J; See, D; Schroeder, E; Tilles, J

    1997-08-15

    A rule-based expert system, Customized Treatment Strategies for HIV (CTSHIV), which encodes information from the literature on known drug-resistant mutations was developed. Additional rules include ranking and weighting based on antiviral activities, redundant mechanisms of action, overlapping toxicities, relative levels of drug-resistance, and proportion of drug-resistant clones in the HIV quasispecies. Plasma was obtained from HIV-infected patients and the RNA was extracted. Segments of the HIV pol gene encoding the entire protease, reverse transcriptase, and integrase proteins were amplified by reverse transcriptase-polymerase chain reaction (using a total of three primer pairs) and cloned. Sequencing was performed on five clones from each of two patients. When the patient's RNA sequencing data were entered into the expert program, and the information was downloaded directly into the CTSHIV program, the five most effective two, three, and four drug regimens coupled with an explanation for their choice were displayed for each patient. Thus, the CTSHIV system couples efficient genetic sequencing with an expert program that recommends regimens based on information in the current medical literature. It may serve as a useful tool in the design of clinical trials and in the management of HIV-infected patients. PMID:9342255

  13. YUCSA: A CLIPS expert database system to monitor academic performance

    NASA Technical Reports Server (NTRS)

    Toptsis, Anestis A.; Ho, Frankie; Leindekar, Milton; Foon, Debra Low; Carbonaro, Mike

    1991-01-01

    The York University CLIPS Student Administrator (YUCSA), an expert database system implemented in C Language Integrated Processing System (CLIPS), for monitoring the academic performance of undergraduate students at York University, is discussed. The expert system component in the system has already been implemented for two major departments, and it is under testing and enhancement for more departments. Also, more elaborate user interfaces are under development. We describe the design and implementation of the system, problems encountered, and immediate future plans. The system has excellent maintainability and it is very efficient, taking less than one minute to complete an assessment of one student.

  14. ICE System: Interruptible control expert system. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Vezina, James M.

    1990-01-01

    The Interruptible Control Expert (ICE) System is based on an architecture designed to provide a strong foundation for real-time production rule expert systems. Three principles are adopted to guide the development of ICE. A practical delivery platform must be provided, no specialized hardware can be used to solve deficiencies in the software design. Knowledge of the environment and the rule-base is exploited to improve the performance of a delivered system. The third principle of ICE is to respond to the most critical event, at the expense of the more trivial tasks. Minimal time is spent on classifying the potential importance of environmental events with the majority of the time used for finding the responses. A feature of the system, derived from all three principles, is the lack of working memory. By using a priori information, a fixed amount of memory can be specified for the hardware platform. The absence of working memory removes the dangers of garbage collection during the continuous operation of the controller.

  15. Use Of Probabilistic Risk Assessment (PRA) In Expert Systems To Advise Nuclear Plant Operators And Managers

    NASA Astrophysics Data System (ADS)

    Uhrig, Robert E.

    1988-03-01

    The use of expert systems in nuclear power plants to provide advice to managers, supervisors and/or operators is a concept that is rapidly gaining acceptance. f2 Generally, expert systems rely on the expertise of human experts or knowledge that has been codified in publications, books, or regulations to provide advice under a wide variety of conditions. In this work, a probabilistic risk assessment (PRA)3 of a nuclear power plant performed previously is used to assess the safety status of nuclear power plants and to make recommendations to the plant personnel. Nuclear power plants have many redundant systems and can continue to operate when one or more of these systems is disabled or removed from service for maintenance or testing. PRAs provide a means of evaluating the risk to the public associated with the operation of nuclear power plants with components or systems out of service. While the choice of the "source term" and methodology in a PRA may influence the absolute probability and consequences of a core melt, the ratio of two PRA calculations for two configurations of the same plant, carried out on a consistent basis, can readily identify the increase in risk associated with going from one configuration to the other. PRISIM,4 a personal computer program to calculate the ratio of core melt probabilities described above (based on previously performed PRAs), has been developed under the sponsorship of the U.S. Nuclear Regulatory Commission (NRC). When one or several components are removed from service, PRISM then calculates the ratio of the core melt probabilities. The inference engine of the expert system then uses this ratio and a constant risk criterion,5 along with information from its knowledge base (which includes information from the PRA), to advise plant personnel as to what action, if any, should be taken.

  16. Refinement of the HEPAR expert system: tools and techniques.

    PubMed

    Lucas, P

    1994-04-01

    Methods and tools for the static and dynamic verification and validation of software systems are commonplace in the field of software engineering. In the field of expert systems, where it is more difficult to ensure that a system meets the specifications and expectations than in traditional software engineering, such tools are generally not available. In this paper, the need for more support of the development process by methods and tools is illustrated by the approach taken in building the HEPAR system, a rule-based expert system that can be used as a supportive tool in the diagnosis of disorders of the liver and biliary tract. At a certain stage in the development of this system an incremental development methodology has been adopted, in which implementation of parts of the expert system was followed by dynamic validation. For this purpose, a collection of software tools were implemented as extensions to a rule-based expert-system shell. These tools provide valuable information about the effects of modification of the HEPAR knowledge base, and indicate places in the knowledge base for refinement. It is believed that similar software tools may prove helpful in the development of other expert systems as well. PMID:8049756

  17. The Diagnostic Value of Skin Disease Diagnosis Expert System

    PubMed Central

    Jeddi, Fatemeh Rangraz; Arabfard, Masoud; Arabkermany, Zahra; Gilasi, Hamidreza

    2016-01-01

    Background: Evaluation is a necessary measure to ensure the effectiveness and efficiency of all systems, including expert systems. The aim of this study was to determine the diagnostic value of expert system for diagnosis of complex skin diseases. Methods: A case-control study was conducted in 2015 to determine the diagnostic value of an expert system. The study population included patients who were referred to Razi Specialized Hospital, affiliated to Tehran University of Medical Sciences. The control group was selected from patients without the selected skin diseases. Data collection tool was a checklist of clinical signs of diseases including pemphigus vulgaris, lichen planus, basal cell carcinoma, melanoma, and scabies. The sample size formula estimated 400 patients with skin diseases selected by experts and 200 patients without the selected skin diseases. Patient selection was undertaken with randomized stratified sampling and their sign and symptoms were logged into the system. Physician’s diagnosis was determined as the gold standard and was compared with the diagnosis of expert system by SPSS software version 16 and STATA. Kappa statistics, indicators of sensitivity, specificity, accuracy and confidence intervals were calculated for each disease. An accuracy of 90% was considered appropriate. Results: Comparing the results of expert system and physician’s diagnosis at the evaluation stage showed an accuracy of 97.1%, sensitivity of 97.5% and specificity of 96.5% The Kappa test indicated a high agreement of 93.6%. Conclusion: The expert system can diagnose complex skin diseases. Development of such systems is recommended to identify all skin diseases. PMID:27046943

  18. Transferring Knowledge: A Parallel between Teaching Chemical Engineering and Developing Expert Systems.

    ERIC Educational Resources Information Center

    Roberge, P. R.

    1990-01-01

    Discussed are expert systems development and teaching, the representation and processing of knowledge, knowledge representation in chemical engineering, and expert systems in chemical engineering. The seven phases of expert system development are illustrated. (CW)

  19. A knowledge based expert system for condition monitoring

    SciTech Connect

    Selkirk, C.G.; Roberge, P.R.; Fisher, G.F.; Yeung, K.K.

    1994-12-31

    Condition monitoring (CM) is the focus of many maintenance philosophies around the world today. In the Canadian Forces (CF), CM has played an important role in the maintenance of aircraft systems since the introduction of spectrometric oil analysis (SOAP) over twenty years ago. Other techniques in use in the CF today include vibration analysis (VA), ferrography, and filter debris analysis (FDA). To improve the usefulness and utility gained from these CM techniques, work is currently underway to incorporate expert systems into them. An expert system for FDA is being developed which will aid filter debris analysts in identifying wear debris and wear level trends, and which will provide the analyst with reference examples in an attempt to standardize results. Once completed, this knowledge based expert system will provide a blueprint from which other CM expert systems can be created. Amalgamating these specific systems into a broad based global system will provide the CM analyst with a tool that will be able to correlate data and results from each of the techniques, thereby increasing the utility of each individual method of analysis. This paper will introduce FDA and then outline the development of the FDA expert system and future applications.

  20. Spacelab Data Processing Facility (SLDPF) quality assurance expert systems development

    NASA Technical Reports Server (NTRS)

    Basile, Lisa R.; Kelly, Angelita C.

    1987-01-01

    The Spacelab Data Processing Facility (SLDPF) is an integral part of the Space Shuttle data network for missions that involve attached scientific payloads. Expert system prototypes were developed to aid in the performance of the quality assurance function of the Spacelab and/or Attached Shuttle Payloads processed telemetry data. The Spacelab Input Processing System (SIPS) and the Spacelab Output Processing System (SOPS), two expert systems, were developed to determine their feasibility and potential in the quality assurance of processed telemetry data. The capabilities and performance of these systems are discussed.

  1. Empirical Analysis and Refinement of Expert System Knowledge Bases

    PubMed Central

    Weiss, Sholom M.; Politakis, Peter; Ginsberg, Allen

    1986-01-01

    Recent progress in knowledge base refinement for expert systems is reviewed. Knowledge base refinement is characterized by the constrained modification of rule-components in an existing knowledge base. The goals are to localize specific weaknesses in a knowledge base and to improve an expert system's performance. Systems that automate some aspects of knowledge base refinement can have a significant impact on the related problems of knowledge base acquisition, maintenance, verification, and learning from experience. The SEEK empiricial analysis and refinement system is reviewed and its successor system, SEEK2, is introduced. Important areas for future research in knowledge base refinement are described.

  2. Implementation of an Expert System for Instructional Design, Phase 3. Design Document and Technical Report.

    ERIC Educational Resources Information Center

    Merrill, M. David; Li, Zhongmin

    Instructional Design Expert (ID Expert) is a prototype instructional design expert system which supports the instructional design phase of instructional system development. Phase 2 of ID Expert was implemented using S.1 expert system language on the VAX computer. The user interface was text-based, consisting of a question/answer dialogue primarily…

  3. Towards a Fuzzy Expert System on Toxicological Data Quality Assessment.

    PubMed

    Yang, Longzhi; Neagu, Daniel; Cronin, Mark T D; Hewitt, Mark; Enoch, Steven J; Madden, Judith C; Przybylak, Katarzyna

    2013-01-01

    Quality assessment (QA) requires high levels of domain-specific experience and knowledge. QA tasks for toxicological data are usually performed by human experts manually, although a number of quality evaluation schemes have been proposed in the literature. For instance, the most widely utilised Klimisch scheme1 defines four data quality categories in order to tag data instances with respect to their qualities; ToxRTool2 is an extension of the Klimisch approach aiming to increase the transparency and harmonisation of the approach. Note that the processes of QA in many other areas have been automatised by employing expert systems. Briefly, an expert system is a computer program that uses a knowledge base built upon human expertise, and an inference engine that mimics the reasoning processes of human experts to infer new statements from incoming data. In particular, expert systems have been extended to deal with the uncertainty of information by representing uncertain information (such as linguistic terms) as fuzzy sets under the framework of fuzzy set theory and performing inferences upon fuzzy sets according to fuzzy arithmetic. This paper presents an experimental fuzzy expert system for toxicological data QA which is developed on the basis of the Klimisch approach and the ToxRTool in an effort to illustrate the power of expert systems to toxicologists, and to examine if fuzzy expert systems are a viable solution for QA of toxicological data. Such direction still faces great difficulties due to the well-known common challenge of toxicological data QA that "five toxicologists may have six opinions". In the meantime, this challenge may offer an opportunity for expert systems because the construction and refinement of the knowledge base could be a converging process of different opinions which is of significant importance for regulatory policy making under the regulation of REACH, though a consensus may never be reached. Also, in order to facilitate the implementation

  4. An evaluation of expert systems for software engineering management

    NASA Technical Reports Server (NTRS)

    Ramsey, Connie Loggia; Basili, Victor R.

    1989-01-01

    The development of four separate prototype expert systems to aid in software engineering management is described. Given the values for certain metrics, these systems provide interpretations which explain any abnormal patterns of these values during the development of a software project. The four expert systems, which solve the same problem, were built using two different approaches to knowledge acquisition, a bottom-up approach and a top-down approach, and two different expert system methods, rule-based deduction and frame-based abduction. In a comparison to see which methods might better suit the needs of this field, it was found that the bottom-up approach led to better results than did the top-down approach, and the rule-based deduction systems using simple rules provided more complete and correct solutions than did the frame-based abduction systems.

  5. Web-based expert system for foundry pollution prevention

    NASA Astrophysics Data System (ADS)

    Moynihan, Gary P.

    2004-02-01

    Pollution prevention is a complex task. Many small foundries lack the in-house expertise to perform these tasks. Expert systems are a type of computer information system that incorporates artificial intelligence. As noted in the literature, they provide a means of automating specialized expertise. This approach may be further leveraged by implementing the expert system on the internet (or world-wide web). This will allow distribution of the expertise to a variety of geographically-dispersed foundries. The purpose of this research is to develop a prototype web-based expert system to support pollution prevention for the foundry industry. The prototype system identifies potential emissions for a specified process, and also provides recommendations for the prevention of these contaminants. The system is viewed as an initial step toward assisting the foundry industry in better meeting government pollution regulations, as well as improving operating efficiencies within these companies.

  6. Expert operator's associate: A knowledge based system for spacecraft control

    NASA Technical Reports Server (NTRS)

    Nielsen, Mogens; Grue, Klaus; Lecouat, Francois

    1991-01-01

    The Expert Operator's Associate (EOA) project is presented which studies the applicability of expert systems for day-to-day space operations. A prototype expert system is developed, which operates on-line with an existing spacecraft control system at the European Space Operations Centre, and functions as an 'operator's assistant' in controlling satellites. The prototype is demonstrated using an existing real-time simulation model of the MARECS-B2 telecommunication satellite. By developing a prototype system, the extent to which reliability and effectivens of operations can be enhanced by AI based support is examined. In addition the study examines the questions of acquisition and representation of the 'knowledge' for such systems, and the feasibility of 'migration' of some (currently) ground-based functions into future spaceborne autonomous systems.

  7. Lighting And Optics Expert System For Machine Vision

    NASA Astrophysics Data System (ADS)

    Novini, Amir

    1989-03-01

    Machine Vision and the field of Artificial Intelligence are both new technologies which have evolved mainly within the past decade with the growth of computers and microchips. And, although research continues, both have emerged from the experimental state to industrial reality. Today's machine vision systems are solving thousands of manufacturing problems in various industries, and the impact of Artificial Intelligence, and more specifically, the use of "Expert Systems" in industry is also being realized. This paper will examine how the two technologies can cross paths, and how an Expert System can become an important part of an overall machine vision solution. An actual example of a development of an Expert System that helps solve machine vision lighting and optics problems will be discussed. The lighting and optics Expert System was developed to assist the end user to configure the "Front End" of a vision system to help solve the overall machine vision problem more effectively, since lack of attention to lighting and optics has caused many failures of this technology. Other areas of machine vision technology where Expert Systems could apply will also be discussed.

  8. Lighting And Optics Expert System For Machine Vision

    NASA Astrophysics Data System (ADS)

    Novini, Amir

    1988-12-01

    Machine Vision and the field of Artificial Intelligence are both new technologies which have evolved mainly within the past decade with the growth of computers and microchips. And, although research continues, both have emerged from the experimental state to industrial reality. Today's machine vision systems are solving thousands of manufacturing problems in various industries, and the impact of Artificial Intelligence, and more specifically, the use of "Expert Systems" in industry is also being realized. This paper will examine how the two technologies can cross paths, and how an Expert System can become an important part of an overall machine vision solution. An actual example of a development of an Expert System that helps solve machine vision lighting and optics problems will be discussed. The lighting and optics Expert System was developed to assist the end user to configure the "Front End" of a vision system to help solve the overall machine vision problem more effectively, since lack of attention to lighting and optics has caused many failures of this technology. Other areas of machine vision technology where Expert Systems could apply will also be discussed.

  9. Evaluation of expert system application based on usability aspects

    NASA Astrophysics Data System (ADS)

    Munaiseche, C. P. C.; Liando, O. E. S.

    2016-04-01

    Usability usually defined as a point of human acceptance to a product or a system based on understands and right reaction to an interface. The performance of web application has been influence by the quality of the interface of that web to supporting information transfer process. Preferably, before the applications of expert systems were installed in the operational environment, these applications must be evaluated first by usability testing. This research aimed to measure the usability of the expert system application using tasks as interaction media. This study uses an expert system application to diagnose skin disease in human using questionnaire method which utilize the tasks as interaction media in measuring the usability. Certain tasks were executed by the participants in observing usability value of the application. The usability aspects observed were learnability, efficiency, memorability, errors, and satisfaction. Each questionnaire question represent aspects of usability. The results present the usability value for each aspect and the total average merit for all the five-usability aspect was 4.28, this indicated that the tested expert system application is in the range excellent for the usability level, so the application can be implemented as the operated system by user. The main contribution of the study is the research became the first step in using task model in the usability evaluation for the expert system application software.

  10. A generic expert system for materials processing in space

    NASA Technical Reports Server (NTRS)

    Andersen, Kristinn; Cook, George E.; Strauss, Alvin M.

    1988-01-01

    A generic expert system is described for inspecting materials processed in space (MPS). The system may be applied, with the appropriate knowledge base, to any of the nondestructive testing methods (NDT) which are appropriate to MPS. Regardless of the method being used, the inspection process consists of three tasks: (1) signal or image processing of the NDT output and feature extraction, (2) interpretation of features in terms of MPS discontinuities, and (3) evaluation of the quality of the MPS based upon industry standards. In contrast to rule based systems, this system represents its knowledge as multidimensional vectors and appropriate functions on them. Currently, the expert system accepts manual input of observed features. Once the expert system has been tested and compared to human expert inspectors, a vision front-end will be developed to complete automation of the expert MPS inspection system, based on visual discontuities. Then the data base will be extended to include a variety of other NDT methods. In addition to functional performance, ease of use was established through menu window driven input as well as flexibility in building, using and modifying data bases for different applications.

  11. Verification of Triple Modular Redundancy (TMR) Insertion for Reliable and Trusted Systems

    NASA Technical Reports Server (NTRS)

    Berg, Melanie; LaBel, Kenneth A.

    2016-01-01

    We propose a method for TMR insertion verification that satisfies the process for reliable and trusted systems. If a system is expected to be protected using TMR, improper insertion can jeopardize the reliability and security of the system. Due to the complexity of the verification process, there are currently no available techniques that can provide complete and reliable confirmation of TMR insertion. This manuscript addresses the challenge of confirming that TMR has been inserted without corruption of functionality and with correct application of the expected TMR topology. The proposed verification method combines the usage of existing formal analysis tools with a novel search-detect-and-verify tool. Field programmable gate array (FPGA),Triple Modular Redundancy (TMR),Verification, Trust, Reliability,

  12. Contingency support using adaptive telemetry extractor and expert system technologies

    NASA Technical Reports Server (NTRS)

    Bryant, Thomas; Cruse, Bryant; Wende, Charles

    1987-01-01

    The 'telemetry analysis logic for operations support' prototype system constitutes an expert system that is charged with contingency planning for the NASA Hubble Space Telescope (HST); this system has demonstrated the feasibility of using an adaptive telemetry extractor/reformatter that is integrated with an expert system. A test case generated by a simulator has demonstrated the reduction of the time required for analysis of a complex series of failures to a few minutes, from the hour usually required. The HST's telemetry extractor will be able to read real-time engineering telemetry streams and disk-based data. Telemetry format changes will be handled almost instantaneously.

  13. Embedded expert system for space shuttle main engine maintenance

    NASA Technical Reports Server (NTRS)

    Pooley, J.; Thompson, W.; Homsley, T.; Teoh, W.; Jones, J.; Lewallen, P.

    1987-01-01

    The SPARTA Embedded Expert System (SEES) is an intelligent health monitoring system that directs analysis by placing confidence factors on possible engine status and then recommends a course of action to an engineer or engine controller. The technique can prevent catastropic failures or costly rocket engine down time because of false alarms. Further, the SEES has potential as an on-board flight monitor for reusable rocket engine systems. The SEES methodology synergistically integrates vibration analysis, pattern recognition and communications theory techniques with an artificial intelligence technique - the Embedded Expert System (EES).

  14. A relational approach to the development of expert diagnostic systems

    NASA Technical Reports Server (NTRS)

    Ames, K. R.

    1984-01-01

    The proposition that, given a structural and/or functional description of any real or abstract system, an expert system can be built based on this description is examined. First, a model is developed for a microprocessor-controlled end effector/sensor system using a modeling approach called a relational Knowledge-Base Machine (RKBM). Next, an explanation of how the end effector model could be used for the error diagnosis on the operational end effector is given and two versions of an error diagnosis algorithm based on the model are presented. Finally, areas of further research are described that are necessary before an expert system using this approach becomes a reality.

  15. Automatic Interpretation Of Electroencephalograms By Means Of An Expert System

    NASA Astrophysics Data System (ADS)

    Jansen, Ben H.

    1985-12-01

    An overview is presented of an expert system approach to the automatic interpretation of recordings of the electrical activity of the brain (electroencephalogram, or EEG). The method consists of a quantification module and a rule-based expert system. Quantification is done by means of autoregressive spectral estimation. It was found that the rule-based system correctly classified 93% of EEGs taken from renal patients, and a 70% agree-ment was found between the system and an electroencephalographer in an experiment aimed at determining the depth of sleep in normal subjects. An indication of how this approach may be used for spectral pattern recognition concludes this paper.

  16. An expert system to perform on-line controller tuning

    NASA Technical Reports Server (NTRS)

    Litt, Jonathan S.

    1990-01-01

    An expert system which tunes a Proportional-Integral-Derivative (PID) controller on-line for a single-input-single-output multiple-lag process with dead time is described. The expert system examines features of the previous transient responses and their corresponding sets of controller parameters. It determines a new set of controller gains to obtain a more desirable time response. This technique can be used to determine and implement a different set of PID gains for each operating regime and, once in steady state, the system can be used to find optimal parameters for load disturbance rejection. The expert system can be applied to any system of the specified form (aerospace, industrial, etc.) and can be expanded to include additional process models.

  17. An expert system to perform on-line controller tuning

    NASA Technical Reports Server (NTRS)

    Litt, Jonathan

    1990-01-01

    An expert system which tunes a proportional-integral-derivative (PID) controller online for a single-input-single-output multiple-lag process with dead time is described. The expert system examines features of the previous transient responses and their corresponding sets of controller parameters. It determines a new set of controller gains to obtain a more desirable time response. This technique can be used to determine and implement a different set of PID gains for each operating regime and, once in steady state, the system can be used to find optimal parameters for load disturbance rejection. The expert system can be applied to any system of the specified form (aerospace, industrial, etc.) and can be expanded to include additional process models.

  18. A framework for building real-time expert systems

    NASA Technical Reports Server (NTRS)

    Lee, S. Daniel

    1991-01-01

    The Space Station Freedom is an example of complex systems that require both traditional and artificial intelligence (AI) real-time methodologies. It was mandated that Ada should be used for all new software development projects. The station also requires distributed processing. Catastrophic failures on the station can cause the transmission system to malfunction for a long period of time, during which ground-based expert systems cannot provide any assistance to the crisis situation on the station. This is even more critical for other NASA projects that would have longer transmission delays (e.g., the lunar base, Mars missions, etc.). To address these issues, a distributed agent architecture (DAA) is proposed that can support a variety of paradigms based on both traditional real-time computing and AI. The proposed testbed for DAA is an autonomous power expert (APEX) which is a real-time monitoring and diagnosis expert system for the electrical power distribution system of the space station.

  19. An expert system for spectroscopic analysis of rocket engine plumes

    NASA Technical Reports Server (NTRS)

    Reese, Greg; Valenti, Elizabeth; Alphonso, Keith; Holladay, Wendy

    1991-01-01

    The expert system described in this paper analyzes spectral emissions of rocket engine exhaust plumes and shows major promise for use in engine health diagnostics. Plume emission spectroscopy is an important tool for diagnosing engine anomalies, but it is time-consuming and requires highly skilled personnel. The expert system was created to alleviate such problems. The system accepts a spectral plot in the form of wavelength vs intensity pairs and finds the emission peaks in the spectrum, lists the elemental emitters present in the data and deduces the emitter that produced each peak. The system consists of a conventional language component and a commercially available inference engine that runs on an Apple Macintosh computer. The expert system has undergone limited preliminary testing. It detects elements well and significantly decreases analysis time.

  20. CRN5EXP: Expert system for statistical quality control

    NASA Technical Reports Server (NTRS)

    Hentea, Mariana

    1991-01-01

    The purpose of the Expert System CRN5EXP is to assist in checking the quality of the coils at two very important mills: Hot Rolling and Cold Rolling in a steel plant. The system interprets the statistical quality control charts, diagnoses and predicts the quality of the steel. Measurements of process control variables are recorded in a database and sample statistics such as the mean and the range are computed and plotted on a control chart. The chart is analyzed through patterns using the C Language Integrated Production System (CLIPS) and a forward chaining technique to reach a conclusion about the causes of defects and to take management measures for the improvement of the quality control techniques. The Expert System combines the certainty factors associated with the process control variables to predict the quality of the steel. The paper presents the approach to extract data from the database, the reason to combine certainty factors, the architecture and the use of the Expert System. However, the interpretation of control charts patterns requires the human expert's knowledge and lends to Expert Systems rules.

  1. Distributed expert systems for ground and space applications

    NASA Technical Reports Server (NTRS)

    Buckley, Brian; Wheatcraft, Louis

    1992-01-01

    Presented here is the Spacecraft Command Language (SCL) concept of the unification of ground and space operations using a distributed approach. SCL is a hybrid software environment borrowing from expert system technology, fifth generation language development, and multitasking operating system environments. Examples of potential uses for the system and current distributed applications of SCL are given.

  2. Mathematical modelling and expert system for battery management

    NASA Astrophysics Data System (ADS)

    Boscher, Jacques; Marrot, Pascal; Bouridah, Karim

    1989-08-01

    The GIBUS expert system, designed to improve management of batteries on board satellites by test center operators, is described. The long term prospects of the project are the development of an operators support system at ground based control centers managing on-satellite storage batteries. An on-board self-management system is suggested as a possible extension of the program.

  3. Online Patent Searching: Guided by an Expert System.

    ERIC Educational Resources Information Center

    Ardis, Susan B.

    1990-01-01

    Describes the development of an expert system for online patent searching that uses menu driven software to interpret the user's knowledge level and the general nature of the search problem. The discussion covers the rationale for developing such a system, current system functions, cost effectiveness, user reactions, and plans for future…

  4. Interactive Learning Using Expert System Quizzes on the Internet.

    ERIC Educational Resources Information Center

    Byers, John A.

    1999-01-01

    Describes a software system that allows teachers and students in practically any subject to make interactive expert systems of quizzes on the Internet. Discusses the design of the system, including building a database of questions and answers; integrating text files of questions and answers with JavaScript-HTML pages; and the JavaScript and HTML…

  5. Research and development for Onboard Navigation (ONAV) ground based expert/trainer system: ONAV entry expert system code

    NASA Technical Reports Server (NTRS)

    Bochsler, Daniel C.

    1988-01-01

    A complete listing is given of the expert system rules for the Entry phase of the Onboard Navigation (ONAV) Ground Based Expert Trainer System for aircraft/space shuttle navigation. These source listings appear in the same format as utilized and required by the C Language Integrated Production System (CLIPS) expert system shell which is the basis for the ONAV entry system. A schematic overview is given of how the rules are organized. These groups result from a partitioning of the rules according to the overall function which a given set of rules performs. This partitioning was established and maintained according to that established in the knowledge specification document. In addition, four other groups of rules are specified. The four groups (control flow, operator inputs, output management, and data tables) perform functions that affect all the other functional rule groups. As the name implies, control flow ensures that the rule groups are executed in the order required for proper operation; operator input rules control the introduction into the CLIPS fact base of various kinds of data required by the expert system; output management rules control the updating of the ONAV expert system user display screen during execution of the system; and data tables are static information utilized by many different rule sets gathered in one convenient place.

  6. An evaluation plan of bus architectures and protocols using the NASA Ames intelligent redundant actuation system

    NASA Technical Reports Server (NTRS)

    Defeo, P.; Chen, M.

    1987-01-01

    Means for evaluating data bus architectures and protocols for highly integrated flight control system applications are needed. Described are the criteria and plans to do this by using the NASA/Ames Intelligent Redundant Actuation System (IRAS) experimental set-up. Candidate bus architectures differ from one another in terms of: topology, access control, message transfer schemes, message characteristics, initialization. data flow control, transmission rates, fault tolerance, and time synchronization. The evaluation criteria are developed relative to these features. A preliminary, analytical evaluation of four candidate busses (MIL-STD-1553B, DATAC, Ethernet, and HSIS) is described. A bus must be exercised in a real-time environment to evaluate its dynamic characteristics. A plan for real-time evaluation of these four busses using a combination of hardware and simulation techniques is presented.

  7. Force-reflecting control of a teleoperated system coupling a nonredundant master with a redundant slave

    SciTech Connect

    Kress, R.; Jansen, J.; DePiero, F.; Babcock, S.

    1990-01-01

    A bilateral, force-reflecting controller was formulated for a 6- Degree-of-Freedom (6-DOF) master operating a 7-DOF slave. Six degrees of freedom are required to arbitrarily position and orient a manipulator and effector. A 7-DOF slave manipulator is desirable because the additional (or redundant) degree of freedom potentially allows for an infinite number of manipulator configurations for a given end effector position and orientation, thus permitting the manipulator to reach around obstacles to perform a task, to avoid joint limits, or to optimize its confinguration in some other manner. A master/slave control system was formulated using a stiffness controller for the master and a gradient-projection algorithm for the slave. The complete control system provides scaled position tracking and indexing between slave and master and force reflection between master and slave. 11 refs., 1 fig.

  8. Attacking the information access problem with expert systems

    NASA Technical Reports Server (NTRS)

    Ragusa, James M.; Orwig, Gary W.

    1991-01-01

    The results of applications research directed at finding an improved method of storing and accessing information are presented. Twelve microcomputer-based expert systems shells and five laser-optical formats have been studied, and the general and specific methods of interfacing these technologies are being tested in prototype systems. Shell features and interfacing capabilities are discussed, and results from the study of five laser-optical formats are recounted including the video laser, compact, and WORM disks, and laser cards and film. Interfacing, including laser disk device driver interfacing, is discussed and it is pointed out that in order to control the laser device from within the expert systems application, the expert systems shell must be able to access the device driver software. Potential integrated applications are investigated and an initial list is provided including consumer services, travel, law enforcement, human resources, marketing, and education and training.

  9. Medical expert systems developed in j.MD, a Java based expert system shell: application in clinical laboratories.

    PubMed

    Van Hoof, Viviane; Wormek, Arno; Schleutermann, Sylvia; Schumacher, Theo; Lothaire, Olivier; Trendelenburg, Christian

    2004-01-01

    Growing complexity of diagnostic tests, combined with increased workload, stringent laboratory accreditation demands, continuous shortening of turn-around-time and budget restrictions have forced laboratories to automate most of their iterative tasks. Introduction of artificial intelligence by means of expert systems has gained an important place in this automation process. Different parts of clinical laboratory activity can benefit from their implementation and the present project deals with one aspect, namely the clinical interpretation of diagnostic tests. This paper describes how j.MD, a new Java based expert system shell, was used to reprogram the expert system for interpretation of amylase isoenzyme patterns that has been in use for many years in our laboratory, and that was originally programmed in Pro.MD, a Prolog based expert system shell. One of the most important advantages of the j.MD system is its bidirectional link with the laboratory information system. This project shows how expert systems for the interpretation of complex diagnostic tests that demand specific expertise can become an integrated part of the automated clinical chemistry lab. PMID:15360781

  10. Expert systems tools for Hubble Space Telescope observation scheduling

    NASA Technical Reports Server (NTRS)

    Miller, Glenn; Rosenthal, Don; Cohen, William; Johnston, Mark

    1987-01-01

    The utility of expert systems techniques for the Hubble Space Telescope (HST) planning and scheduling is discussed and a plan for development of expert system tools which will augment the existing ground system is described. Additional capabilities provided by these tools will include graphics-oriented plan evaluation, long-range analysis of the observation pool, analysis of optimal scheduling time intervals, constructing sequences of spacecraft activities which minimize operational overhead, and optimization of linkages between observations. Initial prototyping of a scheduler used the Automated Reasoning Tool running on a LISP workstation.

  11. An expert system that performs a satellite station keepimg maneuver

    NASA Technical Reports Server (NTRS)

    Linesbrowning, M. Kate; Stone, John L., Jr.

    1987-01-01

    The development and characteristics of a prototype expert system, Expert System for Satellite Orbit Control (ESSOC), capable of providing real-time spacecraft system analysis and command generation for a geostationary satellite are described. The ESSOC recommends appropriate commands that reflect both the changing spacecraft condition and previous procedural action. An internal knowledge base stores satellite status information and is updated with processed spacecraft telemetry. Procedural structure data are encoded in production rules. Structural methods of knowledge acquisition and the design and performance-enhancing techniques that enable ESSOC to operate in real time are also considered.

  12. Evaluation of Fuzzy Rulemaking for Expert Systems for Failure Detection

    NASA Technical Reports Server (NTRS)

    Laritz, F.; Sheridan, T. B.

    1984-01-01

    Computer aids in expert systems were proposed to diagnose failures in complex systems. It is shown that the fuzzy set theory of Zadeh offers a new perspective for modeling for humans thinking and language use. It is assumed that real expert human operators of aircraft, power plants and other systems do not think of their control tasks or failure diagnosis tasks in terms of control laws in differential equation form, but rather keep in mind a set of rules of thumb in fuzzy form. Fuzzy set experiments are described.

  13. An expert system approach to astronomical data analysis

    NASA Technical Reports Server (NTRS)

    Johnston, Mark D.

    1987-01-01

    Expert systems technology has much to offer to the problem of astronomical data analysis, where large data volumes and sophisticated analysis goals have caused a variety of interesting problems to arise. The construction of a prototype expert system whose target domain is CCD image calibration, is reported. The prototype is designed to be extensible to different and more complex problems in a straighforward way, and to be largely independent of the details of the specific data analysis system which executes the plan it generates.

  14. Neural network based expert system for compressor stall monitoring

    NASA Technical Reports Server (NTRS)

    Lo, Ching F.; Shi, G. Z.

    1991-01-01

    This research is designed to apply a new information processing technology, artificial neural networks, to monitoring compressor stall. The outputs of neural networks support the dynamic knowledge data base of an expert system. This is the open-loop mode to avoid compressor stall. The integration of a control system with neural networks is the closed-loop mode in stall avoidance. The feasibility of the concept has been demonstrated for the compressor of 16-foot transonic/supersonic propulsion wind tunnels. The construction of a prototpye expert system has been initiated.

  15. Software For Development Of Expert Systems

    NASA Technical Reports Server (NTRS)

    James, Mark L.; Atkinson, David J.

    1990-01-01

    Modular software system helps create efficient artificial-intelligence computer programs. STAR*TOOL system: Set of high-level software tools; assists programmers in creation of efficient knowledge-based software systems. Provides language and capabilities for compilation of application programs written in Common LISP. Features modularity enabling elimination of unnecessary capabilities from final application program and achieves greater computing performance. Runs on any computer that supports Common LISP and has sufficient memory. Provides programmer with necessary software tools to build wide variety of reasoning and inference engines for such applications as planning, diagnosis and analysis, and simulation.

  16. Expert systems for the transportation of hazardous and radioactive materials

    SciTech Connect

    Luce, C.E.; Clover, J.C.; Ferrada, J.J.

    1994-10-01

    Under the supervision of the Transportation Technologies Group which is in the Chemical Technology Division at Oak Ridge National Laboratory, an expert system prototype for the transportation and packaging of hazardous and radioactive materials has been designed and developed. The development of the expert system prototype focused on using the combination of hypermedia elements and the Visual Basic{trademark} programming language. Hypermedia technology uses software that allows the user to interact with the computing environment through many formats: text, graphics, audio, and full-motion video. With the use of hypermedia, a user-friendly prototype has been developed to sort through numerous transportation regulations, thereby leading to the proper packaging for the materials. The expert system performs the analysis of regulations that an expert in shipping information would do; only the expert system performs the work more quickly. Currently, enhancements in a variety of categories are being made to the prototype. These include further expansion of non-radioactive materials, which includes any material that is hazardous but not radioactive; and the addition of full-motion video, which will depict regulations in terms that are easy to understand and which will show examples of how to handle the materials when packaging them.

  17. An expert system for a distributed real-time trainer

    NASA Technical Reports Server (NTRS)

    Purinton, Steven C.; Wang, Caroline K.

    1988-01-01

    The problem addressed by this expert system concerns the expansion of capability of a Real Time Trainer for the Spacelab flight crew. As requirements for more models or fidelity are placed upon the system, expansion is necessary. The simulator can be expanded using a larger processor or by going to a distributed system and expand by adding additional processors. The distributed system is preferable because it is more economical and can be expanded in a more incremental manner. An expert system was developed to evaluate modeling and timing capability within a real time training simulator. The expert system is based upon a distributed configuration. Components of the modeled system are control tasks, network tasks, emulator tasks, processors, displays, and a network. The distributed module expert system (DMES) allows the configuring of processors, tasks, display use, keyboard use, and selection of alternate methods to update the data buffer. Modules can be defined with execution occurring in a specific processor on a network. The system consists of a knowledge front end editor to interactively generate or update the knowledge base, an inference engine, a display module, and a recording module.

  18. ESP: an expert system for poisoning diagnosis and management.

    PubMed

    Batista-Navarro, Riza Theresa B; Bandojo, Diana A; Gatapia, M A Jaymee Krisette; Santos, Reggie Nicolo C; Marcelo, Alvin B; Panganiban, Lynn Crisanta R; Naval, Prospero C

    2010-03-01

    We describe a clinical decision support system (CDSS) designed to provide timely information germane to poisoning. The CDSS aids medical decision making through recommendations to clinicians for immediate evaluation. The system is implemented as a rule-based expert system with two major components: the knowledge base and the inference engine. The knowledge base serves as the database which contains relevant poisoning information and rules that are used by the inference engine in making decisions. This expert system accepts signs and symptoms observed from a patient as input and presents a list of possible poisoning types with the corresponding management procedures which may be considered in making the final diagnosis. A knowledge acquisition tool (KAT) that allows toxicological experts to update the knowledge base was also developed. This article describes the architecture of the fully featured system, the design of the CDSS and the KAT as web applications, the utilisation of the inferencing mechanism of C Language Integrated Production System (CLIPS), which is an expert system shell that helps the system in decision-making tasks, the methods used as well as problems encountered. We also present the results obtained after testing the system and propose some recommendations for future work. PMID:20726735

  19. What is an expert? A systems perspective on expertise

    PubMed Central

    Caley, Michael Julian; O'Leary, Rebecca A; Fisher, Rebecca; Low-Choy, Samantha; Johnson, Sandra; Mengersen, Kerrie

    2014-01-01

    Expert knowledge is a valuable source of information with a wide range of research applications. Despite the recent advances in defining expert knowledge, little attention has been given to how to view expertise as a system of interacting contributory factors for quantifying an individual's expertise. We present a systems approach to expertise that accounts for many contributing factors and their inter-relationships and allows quantification of an individual's expertise. A Bayesian network (BN) was chosen for this purpose. For illustration, we focused on taxonomic expertise. The model structure was developed in consultation with taxonomists. The relative importance of the factors within the network was determined by a second set of taxonomists (supra-experts) who also provided validation of the model structure. Model performance was assessed by applying the model to hypothetical career states of taxonomists designed to incorporate known differences in career states for model testing. The resulting BN model consisted of 18 primary nodes feeding through one to three higher-order nodes before converging on the target node (Taxonomic Expert). There was strong consistency among node weights provided by the supra-experts for some nodes, but not others. The higher-order nodes, “Quality of work” and “Total productivity”, had the greatest weights. Sensitivity analysis indicated that although some factors had stronger influence in the outer nodes of the network, there was relatively equal influence of the factors leading directly into the target node. Despite the differences in the node weights provided by our supra-experts, there was good agreement among assessments of our hypothetical experts that accurately reflected differences we had specified. This systems approach provides a way of assessing the overall level of expertise of individuals, accounting for multiple contributory factors, and their interactions. Our approach is adaptable to other situations where it

  20. An expert system framework for nondestructive waste assay

    SciTech Connect

    Becker, G.K.

    1996-10-01

    Management and disposition of transuranic (RU) waste forms necessitates determining entrained RU and associated radioactive material quantities as per National RU Waste Characterization Program requirements. Technical justification and demonstration of a given NDA method used to determine RU mass and uncertainty in accordance with program quality assurance is difficult for many waste forms. Difficulties are typically founded in waste NDA methods that employ standards compensation and/or employment of simplifying assumptions on waste form configurations. Capability to determine and justify RU mass and mass uncertainty can be enhanced through integration of waste container data/information using expert system and empirical data-driven techniques with conventional data acquisition and analysis. Presented is a preliminary expert system framework that integrates the waste form data base, alogrithmic techniques, statistical analyses, expert domain knowledge bases, and empirical artificial intelligence modules into a cohesive system. The framework design and bases in addition to module development activities are discussed.

  1. On the soundness and safety of expert systems.

    PubMed

    Fox, J

    1993-04-01

    The problems of developing sound and safe expert systems are discussed, with particular reference to medicine. The concepts, notations, methods, results and technologies which have emerged from the study of mathematical logic as a computational paradigm offer many benefits for improving the quality of expert systems. Logic programming offers a better discipline for design, specification and implementation than ad hoc development methodologies. When logic programming is combined with software engineering methods, such as a software development life-cycle, the probability of routinely developing large-scale yet efficient and sound applications will be increased. However, although soundness is a necessary property of any technology it is not sufficient for assuring safety. Established methods for improved software safety are discussed, and a number of approaches to improving the safety of medical expert systems is identified. The possibility of introducing an appropriately extended life-cycle, and the potential benefits of a formal theory of safety are discussed. PMID:8358492

  2. Using hybrid expert system approaches for engineering applications

    NASA Technical Reports Server (NTRS)

    Allen, R. H.; Boarnet, M. G.; Culbert, C. J.; Savely, R. T.

    1987-01-01

    In this paper, the use of hybrid expert system shells and hybrid (i.e., algorithmic and heuristic) approaches for solving engineering problems is reported. Aspects of various engineering problem domains are reviewed for a number of examples with specific applications made to recently developed prototype expert systems. Based on this prototyping experience, critical evaluations of and comparisons between commercially available tools, and some research tools, in the United States and Australia, and their underlying problem-solving paradigms are made. Characteristics of the implementation tool and the engineering domain are compared and practical software engineering issues are discussed with respect to hybrid tools and approaches. Finally, guidelines are offered with the hope that expert system development will be less time consuming, more effective, and more cost-effective than it has been in the past.

  3. Expert System Approach For Generating And Evaluating Engine Design Alternatives

    NASA Astrophysics Data System (ADS)

    Shen, Stewart N. T.; Chew, Meng-Sang; Issa, Ghassan F.

    1989-03-01

    Artificial intelligence is becoming an increasingly important subject of study for computer scientists, engineering designers, as well as professionals in other fields. Even though AI technology is a relatively new discipline, many of its concepts have already found practical applications. Expert systems, in particular, have made significant contributions to technologies in such fields as business, medicine, engineering design, chemistry, and particle physics. This paper describes an expert system developed to aid the mechanical designer with the preliminary design of variable-stroke internal-combustion engines. The expert system accomplished its task by generating and evaluating a large number of design alternatives represented in the form of graphs. Through the application of structural and design rules directly to the graphs, optimal and near optimal preliminary design configurations of engines are deduced.

  4. The Science of Computing: Expert Systems

    NASA Technical Reports Server (NTRS)

    Denning, Peter J.

    1986-01-01

    The creative urge of human beings is coupled with tremendous reverence for logic. The idea that the ability to reason logically--to be rational--is closely tied to intelligence was clear in the writings of Plato. The search for greater understanding of human intelligence led to the development of mathematical logic, the study of methods of proving the truth of statements by manipulating the symbols in which they are written without regard to the meanings of those symbols. By the nineteenth century a search was under way for a universal system of logic, one capable of proving anything provable in any other system.

  5. An Expert System Helps Students Learn Database Design

    ERIC Educational Resources Information Center

    Post, Gerald V.; Whisenand, Thomas G.

    2005-01-01

    Teaching and learning database design is difficult for both instructors and students. Students need to solve many problems with feedback and corrections. A Web-based specialized expert system was created to enable students to create designs online and receive immediate feedback. An experiment testing the system shows that it significantly enhances…

  6. An expert system to advise astronauts during experiments

    NASA Technical Reports Server (NTRS)

    Young, Laurence R.; Groleau, Nicolas; Szolovits, Peter; Colombano, Silvano P.; Rosenthal, Don; Haymann-Haber, Guido

    1989-01-01

    Work being done on an expert system designed to improve the quality of space experimentation in vestibular physiology is described. Emphasis is given to two of the several modules of which the system architecture is composed: the Protocol Manager and the Interesting Data Filter. Some engineering issues related to human factors and to data acquisition and monitoring are also addressed.

  7. A/C Interface: Expert Systems: Part II.

    ERIC Educational Resources Information Center

    Dessy, Raymond E., Ed.

    1984-01-01

    Discusses working implementations of artificial intelligence systems for chemical laboratory applications. They include expert systems for liquid chromatography, spectral analysis, instrument control of a totally computerized triple-quadrupole mass spectrometer, and the determination of the mineral constituents of a rock sample given the powder…

  8. A Rule-Based Expert System Approach to Academic Advising.

    ERIC Educational Resources Information Center

    Patankar, Manoj

    1998-01-01

    Discusses the development and evaluation of the Academic Counselling Expert (ACE) system designed to replace the faculty advisor and provide requisite advice to aviation students at San Jose State University (California). This computer-based counselling system was accessed by 65 students (Spring 1996 semester); most students acquired appropriate…

  9. Knowledge base for expert system process control/optimization

    NASA Astrophysics Data System (ADS)

    Lee, C. W.; Abrams, Frances L.

    An expert system based on the philosophy of qualitative process automation has been developed for the autonomous cure cycle development and control of the autoclave curing process. The system's knowledge base in the form of declarative rules is based on the qualitative understanding of the curing process. The knowledge base and examples of the resulting cure cycle are presented.

  10. CANSEARCH: An Expert Systems Approach to Document Retrieval.

    ERIC Educational Resources Information Center

    Pollitt, Steven

    1987-01-01

    Describes CANSEARCH, an intermediary computer system incorporating fundamental features of the expert systems approach. Designed to provide access to information on cancer therapy in the MEDLINE database for doctors with no experience in document retrieval, search strategies are explained and menu selection from a touch terminal is illustrated.…

  11. An Expert System Approach to Online Catalog Subject Searching.

    ERIC Educational Resources Information Center

    Khoo, Christopher S. G.; Poo, Danny C. C.

    1994-01-01

    Reviews methods to improve online catalogs for subject searching and describes the design of an expert system front-end to improve subject access in online public access catalogs that focuses on search strategies. Implementation of a prototype system at the National University of Singapore is described, and reformulation strategies are discussed.…

  12. Expert systems for optimization of laser technology processes

    NASA Astrophysics Data System (ADS)

    Maiorov, Vladimir S.; Sternin, M. Y.

    2002-04-01

    Many users of laser technological processes are trying to create data bases accumulating their experience in laser processing of materials. The data bases are useful tools to render help to technicians working with laser machines. But it is only the first step in utilization of intelligent computer programs. In this paper we present the results of the development of expert system (ES) to help technicians in the choice of best conditions for laser processing of materials. The ES has been created on the basis of practical knowledge of experts and experimental results collected to the data base. The set of parameters was developed for the description of laser technological processes. Each of the processes was characterized by the values of such parameters changing in some reasonable diapasons. Those parameters were divided into input and output groups. The input group of parameters included the main technical characteristics of the laser, the type of the material and the demands on the quality of laser processing products. The output group of parameters consisted of the set of laser processing conditions recommended by the expert system. Generally, the ES presents a computer model of the expert's decision making process. The steps of such a process are a new task analysis, search of closest past cases, evaluation of tasks similarity and so on. The expert system called MALS (Machine Learning Shell) is presented in this paper as an example of ES which could give consultations on the best choice of the laser cutting process.

  13. Failure detection and isolation of redundant inertial systems for Space Shuttle

    NASA Technical Reports Server (NTRS)

    Brown, H. E.; Dove, R. W.; Mckern, R. A.

    1973-01-01

    A failure detection and isolation technique is presented for application to 'off-the-shelf' type four-gimbaled inertial measurement units (IMUs) such as the KT-70 or Carousel IV. This study concentrates initially upon actual four-gimbaled IMU performance requirements for current Space Shuttle booster and orbiter mission phases. When this information is obtained for a simplex system, the remaining area of study necessary to attain redundant IMU capabilities is the establishment of mission-dependent performance failure detection thresholds. These thresholds, then, permit a careful evaluation of the capabilities of various 'off-the-shelf' four gimbaled IMUs to satisfy the Shuttle mission performance requirements with various failure detection and isolation methods.

  14. Failure detection and accommodation in structural dynamics systems using analytic redundancy. [in large space structures

    NASA Technical Reports Server (NTRS)

    Williams, J. P.; Montgomery, R. C.

    1985-01-01

    The concept of analytic redundancy is extended to identify nonzero constant output failures in large spacecraft active control sensors and actuators, using a set of distributed sensors which do not nominally produce equivalent signals but are related through the structural dynamics of the system. The suboptimal technique uses a Sequential Probability Ratio Test on the residual sequence of a Kalman filter based on a modal structure model, to determine failure of a component based on an assumed failure hypothesis. The specific failure is identified and then the Kalman filter gains are reconfigured for the identified remaining working sensor set. Experimental data using an apparatus whose dynamics are representative of a large spacecraft show the nominal filter performance under failed and unfailed conditions.

  15. Equifinality and its violations in a redundant system: multifinger accurate force production

    PubMed Central

    Wilhelm, Luke; Zatsiorsky, Vladimir M.

    2013-01-01

    We explored a hypothesis that transient perturbations applied to a redundant system result in equifinality in the space of task-related performance variables but not in the space of elemental variables. The subjects pressed with four fingers and produced an accurate constant total force level. The “inverse piano” device was used to lift and lower one of the fingers smoothly. The subjects were instructed “not to intervene voluntarily” with possible force changes. Analysis was performed in spaces of finger forces and finger modes (hypothetical neural commands to fingers) as elemental variables. Lifting a finger led to an increase in its force and a decrease in the forces of the other three fingers; the total force increased. Lowering the finger back led to a drop in the force of the perturbed finger. At the final state, the sum of the variances of finger forces/modes computed across repetitive trials was significantly higher than the variance of the total force/mode. Most variance of the individual finger force/mode changes between the preperturbation and postperturbation states was compatible with constant total force. We conclude that a transient perturbation applied to a redundant system leads to relatively small variance in the task-related performance variable (equifinality), whereas in the space of elemental variables much more variance occurs that does not lead to total force changes. We interpret the results within a general theoretical scheme that incorporates the ideas of hierarchically organized control, control with referent configurations, synergic control, and the uncontrolled manifold hypothesis. PMID:23904497

  16. Cooperating Expert Systems For Automated Monitoring And Diagnostics

    NASA Technical Reports Server (NTRS)

    Schwuttke, Ursula M.; Veregge, John R.

    1990-01-01

    Human operators freer to perform nonrepetitive tasks. Expert software system for monitoring multiple streams of sensory data from interacting equipment subsystems undergoing development. Organized hierarchically to monitor multiple equipment subsystems simultaneously. Each expert software subsystem responsible for one of equipment subsystems. Intended to assist human analysts in interpretation of telemetry data indicating operating statuses of subsystems of spacecraft, enables analysts to maintain desired mode(s) of operation, and helps to correct anomalies in subsystems or in overall spacecraft system. Other versions devised for industrial monitoring and analysis tasks similarly complicated.

  17. An Expert-System Engine With Operative Probabilities

    NASA Technical Reports Server (NTRS)

    Orlando, N. E.; Palmer, M. T.; Wallace, R. S.

    1986-01-01

    Program enables proof-of-concepts tests of expert systems under development. AESOP is rule-based inference engine for expert system, which makes decisions about particular situation given user-supplied hypotheses, rules, and answers to questions drawn from rules. If knowledge base containing hypotheses and rules governing environment is available to AESOP, almost any situation within that environment resolved by answering questions asked by AESOP. Questions answered with YES, NO, MAYBE, DON'T KNOW, DON'T CARE, or with probability factor ranging from 0 to 10. AESOP written in Franz LISP for interactive execution.

  18. Temporal and contextual knowledge in model-based expert systems

    NASA Technical Reports Server (NTRS)

    Toth-Fejel, Tihamer; Heher, Dennis

    1987-01-01

    A basic paradigm that allows representation of physical systems with a focus on context and time is presented. Paragon provides the capability to quickly capture an expert's knowledge in a cognitively resonant manner. From that description, Paragon creates a simulation model in LISP, which when executed, verifies that the domain expert did not make any mistakes. The Achille's heel of rule-based systems has been the lack of a systematic methodology for testing, and Paragon's developers are certain that the model-based approach overcomes that problem. The reason this testing is now possible is that software, which is very difficult to test, has in essence been transformed into hardware.

  19. A local area computer network expert system framework

    NASA Technical Reports Server (NTRS)

    Dominy, Robert

    1987-01-01

    Over the past years an expert system called LANES designed to detect and isolate faults in the Goddard-wide Hybrid Local Area Computer Network (LACN) was developed. As a result, the need for developing a more generic LACN fault isolation expert system has become apparent. An object oriented approach was explored to create a set of generic classes, objects, rules, and methods that would be necessary to meet this need. The object classes provide a convenient mechanism for separating high level information from low level network specific information. This approach yeilds a framework which can be applied to different network configurations and be easily expanded to meet new needs.

  20. An approach to modeling a kinematically redundant dual manipulator closed chain system using pseudovelocities

    SciTech Connect

    Unseren, M.A.

    1996-05-01

    The paper discusses the problem of resolving the kinematic redundancy in the closed chain formed when two redundant manipulators mutually lift a rigid body object. The positional degrees of freedom (DOF) in the closed chain are parameterized by a set of independent variables termed pseudovelocities. Due to the redundancy there are more DOF and thus more pseudovelocities than are required to specify the motion of the held object. The additional ``redundant`` pseudovelocities are used to minimize the distance between the vector of unknown joint velocities and a vector of ``corrective`` joint velocities in a Euclidean norm sense. This leads to an optimal solution for the joint velocities as a linear function of the Cartesian object velocities and the corrective velocities. The problem of determining the corrective velocities to avoid collisions of the links with a wall located in the workspace and to avoid joint range limits is illustrated by an example of two redundant planar revolute joint manipulators mutually lifting a rigid object.

  1. ANAPPRES: An expert system for interference well-test analysis

    SciTech Connect

    Arellano, V.M.; Iglesias, E.R.; Arellano, J.; Schwarzblat, M.

    1988-01-01

    We present ANAPPRES V1.0, the first version of a computerized expert system capable of analyzing constant- and variable-flowrate interference tests, in which there is one active well and an arbitrary number of observation wells, in liquid-saturated homogeneous reservoirs. ANAPPRES successfully couples mathematical models, optimization techniques, heuristic knowledge and computerized graphics, a combination not often found in published expert systems. Its main advantages are that it is user friendly, requires essentially no experience on the part of the analyst, eliminates subjectivity associated with earlier techniques of analysis, can handle complex cases and large data sets, completes the analysis of even the most complex cases (including plotting the results) in one run, and is significantly faster than a human expert.

  2. PRODIAG: Combined expert system/neural network for process fault diagnosis. Volume 2, Code manual

    SciTech Connect

    Reifman, J.; Wei, T.Y.C.

    1995-09-01

    We recommend the reader first review Volume 1 of this document, Code Theory, before reading Volume 2. In this volume we make extensive use of terms and concepts described and defined in Volume 1 which are not redefined here to the same extent. To try to reduce the amount of redundant information, we have restricted this volume to the presentation of the expert system code and refer back to the theory described in Volume 1 when necessary. Verification and validation of the results are presented in Volume 3, Application, of this document. Volume 3 also presents the implementation of the component characteristics diagnostic approach through artificial neural networks discussed in Volume 1. We decided to present the component characteristics approach in Volume 3, as opposed to write a separate code manual for it, because the approach, although general, requires a case-by-case analysis. The purpose of this volume is to present the details of the expert system (ES) portion o the PRODIAG process diagnostic program. In addition, we present here the graphical diagnostics interface (GDI) and illustrate the combined use of the ES and GDI with a sample problem. For completeness, we provide the file names of all files, programs and major subroutines of these two systems, ES and GDI, and their corresponding location in the Reactor Analysis Division (RA) computer network and Reactor Engineering Division (RE) computer network as of 30 September 1995.

  3. A Model-Based Expert System For Digital Systems Design

    NASA Astrophysics Data System (ADS)

    Wu, J. G.; Ho, W. P. C.; Hu, Y. H.; Yun, D. Y. Y.; Parng, T. M.

    1987-05-01

    In this paper, we present a model-based expert system for automatic digital systems design. The goal of digital systems design is to generate a workable and efficient design from high level specifications. The formalization of the design process is a necessity for building an efficient automatic CAD system. Our approach combines model-based, heuristic best-first search, and meta-planning techniques from AI to facilitate the design process. The design process is decomposed into three subprocesses. First, the high-level behavioral specifications are translated into sequences of primitive behavioral operations. Next, primitive operations are grouped to form intermediate-level behavioral functions. Finally, structural function modules are selected to implement these functions. Using model-based reasoning on the primitive behavioral operations level extends the solution space considered in design and provides more opportunity for minimization. Heuristic best-first search and meta-planning tech-niques control the decision-making in the latter two subprocesses to optimize the final design. They also facilitate system maintenance by separating design strategy from design knowledge.

  4. Generative engineering databases - Toward expert systems

    NASA Technical Reports Server (NTRS)

    Rasdorf, W. J.; Salley, G. C.

    1985-01-01

    Engineering data management, incorporating concepts of optimization with data representation, is receiving increasing attention as the amount and complexity of information necessary for performing engineering operations increases and the need to coordinate its representation and use increases. Research in this area promises advantages for a wide variety of engineering applications, particularly those which seek to use data in innovative ways in the engineering process. This paper presents a framework for a comprehensive, relational database management system that combines a knowledge base of design constraints with a database of engineering data items in order to achieve a 'generative database' - one which automatically generates new engineering design data according to the design constraints stored in the knowledge base. The representation requires a database that is able to store all of the data normally associated with engineering design and to accurately represent the interactions between constraints and the stored data while guaranteeing its integrity. The representation also requires a knowledge base that is able to store all the constraints imposed upon the engineering design process.

  5. Fault-tolerant system considerations for a redundant strapdown inertial measurement unit

    NASA Technical Reports Server (NTRS)

    Motyka, P.; Ornedo, R.; Mangoubi, R.

    1984-01-01

    The development and evaluation of a fault-tolerant system for the Redundant Strapdown Inertial Measurement Unit (RSDIMU) being developed and evaluated by the NASA Langley Research Center was continued. The RSDIMU consists of four two-degree-of-freedom gyros and accelerometers mounted on the faces of a semi-octahedron which can be separated into two halves for damage protection. Compensated and uncompensated fault-tolerant system failure decision algorithms were compared. An algorithm to compensate for sensor noise effects in the fault-tolerant system thresholds was evaluated via simulation. The effects of sensor location and magnitude of the vehicle structural modes on system performance were assessed. A threshold generation algorithm, which incorporates noise compensation and filtered parity equation residuals for structural mode compensation, was evaluated. The effects of the fault-tolerant system on navigational accuracy were also considered. A sensor error parametric study was performed in an attempt to improve the soft failure detection capability without obtaining false alarms. Also examined was an FDI system strategy based on the pairwise comparison of sensor measurements. This strategy has the specific advantage of, in many instances, successfully detecting and isolating up to two simultaneously occurring failures.

  6. An expert system for screening enhanced oil recovery methods

    SciTech Connect

    Parkinson, W.J. ); Luger, G.F. . Dept. of Computer Science); Bretz, R.E.; Osowski, J.J. . Dept. of Petroleum Engineering)

    1990-01-01

    This paper demonstrates how a small expert system can be written with inexpensive shells (CLIPS and EXSHELL) and run on inexpensive personal computers. CLIPS is a forward-chaining rule-based system written in the C language. Rules are entered in a LISP-like format. EXSHELL is a backward-chaining rule-based system written in the PROLOG language. These shells were used to write a small expert system, an expert assistant, which is used to help petroleum engineers screen possible enhanced oil recovery candidate processes. Though the final candidate process is selected on the basis of an economic evaluation, the expert assistant greatly reduces the amount of work involved. The system selects the optimal collection of paths to the solutions and is easily updated as new data become available. This paper also demonstrates the utility and ease of use of these inexpensive shells, compares the approach used by each, and demonstrates the relative advantages of forward-chaining versus backward-chaining for this problem. 11 refs.

  7. A method for knowledge acquisition in diagnostic expert system.

    PubMed

    Li, Weishi; Li, Aiping; Li, Shudong

    2015-01-01

    Knowledge acquisition plays very important role in the diagnostic expert system. It usually takes a long period to acquire disease knowledge using the traditional methods. To solve this problem, this paper describes relations between rough set theory and rule-based description of diseases, which corresponds to the process of knowledge acquisition of diagnostic expert system. Then the exclusive rules, inclusive rules and disease images of disease are built based on the PDES diagnosis model, and the definition of probability rule is put forward. At last, the paper presents the rule-based automated induction reasoning method, including exhaustive search, post-processing procedure, estimation for statistic test and the bootstrap and resampling methods. We also introduce automated induction of the rule-based description, which is used in our diseases diagnostic expert system. The experimental results not only show that rough set theory gives a very suitable framework to represent processes of uncertain knowledge extraction, but also that this method induces diagnostic rules correctly. This method can act as the assistant tool for development of diagnosis expert system, and has an extensive application in intelligent information systems. PMID:26410329

  8. Design of an expert-system flight status monitor

    NASA Technical Reports Server (NTRS)

    Regenie, V. A.; Duke, E. L.

    1985-01-01

    The modern advanced avionics in new high-performance aircraft strains the capability of current technology to safely monitor these systems for flight test prior to their generalized use. New techniques are needed to improve the ability of systems engineers to understand and analyze complex systems in the limited time available during crucial periods of the flight test. The Dryden Flight Research Facility of NASA's Ames Research Center is involved in the design and implementation of an expert system to provide expertise and knowledge to aid the flight systems engineer. The need for new techniques in monitoring flight systems and the conceptual design of an expert-system flight status monitor is discussed. The status of the current project and its goals are described.

  9. Validation, clinical trial, and evaluation of a radiology expert system.

    PubMed

    Kahn, C E

    1991-10-01

    The PHOENIX Radiology Consultant is a rule-based expert system which assists physicians in planning radiological work-up strategies. This article describes the methods used to create and validate the system's knowledge base. The feasibility and acceptability of PHOENIX were tested for two years in a clinical trial. During this period, the system was used 1,421 times, an average of 13.7 times per week, primarily by medical students and nonradiologist physicians. Much of the system's use occurred at night and on weekends, when the radiology department was not fully staffed. Several physicians were enlisted to further evaluate the utility of the system. The results of their evaluation indicate that an expert system that helps physicians select diagnostic-imaging studies can serve as a useful and informative component of a radiology information system, and is particularly useful for medical students and physicians in training. PMID:1762580

  10. Expert system isssues in automated, autonomous space vehicle rendezvous

    NASA Technical Reports Server (NTRS)

    Goodwin, Mary Ann; Bochsler, Daniel C.

    1987-01-01

    The problems involved in automated autonomous rendezvous are briefly reviewed, and the Rendezvous Expert (RENEX) expert system is discussed with reference to its goals, approach used, and knowledge structure and contents. RENEX has been developed to support streamlining operations for the Space Shuttle and Space Station program and to aid definition of mission requirements for the autonomous portions of rendezvous for the Mars Surface Sample Return and Comet Nucleus Sample return unmanned missions. The experience with REMEX to date and recommendations for further development are presented.

  11. Expert system control of a six-legged walking telerobot

    SciTech Connect

    DeVries, K R

    1989-01-01

    The Robotics Technology Group of the Savannah River Laboratory has implemented a three-stage expert system for a six-legged walking telerobot. Remote operation of this machine requires the knowledge of a highly skilled operator. Stability, size, and mode of operation considerations must take place continuously, in general, much more so than with a typical wheeled vehicle. The technology employed provides for quasi-real-time computer control, manual control, and an expert advisor -- all in the same package, which runs on the IBM PC/AT. 2 refs., 5 figs.

  12. Knowledge-based Expert Systems for Crop Identification

    NASA Technical Reports Server (NTRS)

    Smith, T. R.; Estes, J. E. (Principal Investigator); Sailer, C. T.; Tinney, L. R.

    1984-01-01

    The development of an improved understanding of the interactive man machine environment is investigated. In such an environment, as many feature inputs as practical would be automatically derived from a data base and input into an expert system decision making procedure. This procedure could then provide expert assistance to a trained image analyst to upgrade and improve the quantity and accuracy of the information extracted from the input data. A comparison of the similarities and differences between manual and automated image interpretation techniques is also examined.

  13. Process Diagnosis Expert System Using First Principles and Functional Component

    Energy Science and Technology Software Center (ESTSC)

    1998-11-24

    PRODIAG is an expert system that performs online diagnosis of faulty components in thermal hydraulic processes. Given measurements of temperatures, pressure, flows, and liquid levels, PRODIAG identifies the possible faulty component candidates at the process level. It is a stand alone code, but can be used in conjunction with a component level program to distinguish among the possible faulty component candidates.

  14. Towards Expert Systems for the Selection of Search Keys.

    ERIC Educational Resources Information Center

    Fidel, Raya

    1986-01-01

    Analysis of the searching behavior of human intermediaries revealed a routine for selection of search keys--free-text or controlled vocabulary--along a decision tree. Examples of decision rules demonstrate that these rules can be automated to significantly enhance the adaptability of intermediary expert systems. Eight sources are given. (EJS)

  15. Systematic methods for knowledge acquisition and expert system development

    NASA Technical Reports Server (NTRS)

    Belkin, Brenda L.; Stengel, Robert F.

    1991-01-01

    Nine cooperating rule-based systems, collectively called AUTOCREW which were designed to automate functions and decisions associated with a combat aircraft's subsystems, are discussed. The organization of tasks within each system is described; performance metrics were developed to evaluate the workload of each rule base and to assess the cooperation between the rule bases. Simulation and comparative workload results for two mission scenarios are given. The scenarios are inbound surface-to-air-missile attack on the aircraft and pilot incapacitation. The methodology used to develop the AUTOCREW knowledge bases is summarized. Issues involved in designing the navigation sensor selection expert in AUTOCREW's NAVIGATOR knowledge base are discussed in detail. The performance of seven navigation systems aiding a medium-accuracy INS was investigated using Kalman filter covariance analyses. A navigation sensor management (NSM) expert system was formulated from covariance simulation data using the analysis of variance (ANOVA) method and the ID3 algorithm. ANOVA results show that statistically different position accuracies are obtained when different navaids are used, the number of navaids aiding the INS is varied, the aircraft's trajectory is varied, and the performance history is varied. The ID3 algorithm determines the NSM expert's classification rules in the form of decision trees. The performance of these decision trees was assessed on two arbitrary trajectories, and the results demonstrate that the NSM expert adapts to new situations and provides reasonable estimates of the expected hybrid performance.

  16. An expert system based software sizing tool, phase 2

    NASA Technical Reports Server (NTRS)

    Friedlander, David

    1990-01-01

    A software tool was developed for predicting the size of a future computer program at an early stage in its development. The system is intended to enable a user who is not expert in Software Engineering to estimate software size in lines of source code with an accuracy similar to that of an expert, based on the program's functional specifications. The project was planned as a knowledge based system with a field prototype as the goal of Phase 2 and a commercial system planned for Phase 3. The researchers used techniques from Artificial Intelligence and knowledge from human experts and existing software from NASA's COSMIC database. They devised a classification scheme for the software specifications, and a small set of generic software components that represent complexity and apply to large classes of programs. The specifications are converted to generic components by a set of rules and the generic components are input to a nonlinear sizing function which makes the final prediction. The system developed for this project predicted code sizes from the database with a bias factor of 1.06 and a fluctuation factor of 1.77, an accuracy similar to that of human experts but without their significant optimistic bias.

  17. Optimization of low gravity materials processing experiments using expert systems

    NASA Technical Reports Server (NTRS)

    Workman, Gary L.; Choudry, Amar

    1988-01-01

    The use of an expert system for the control of materials processing experiments in a facility such as the Space Station provides a number of attractive features for insuring that certain critical process parameters can be used to optimize the productivity of the materials processing experiments. The proposed approach to implementation of an expert system utilizes a knowledge base of desired process characteristics which will provide the desired results. The knowledge base for each experiment will be created in conjunction with the scientific investigator in charge of the experiment. Improvements to the knowledge base will be expanded to include self learning sessions in ground based experiments in order to teach the expert system how to respond to perturbations in the process and update the knowledge base on what process change should be implemented in order to reach the desired end product. Design considerations using an on-line real time expert system such as PICON is studied. The types of experiments evaluated include several types of solidification experiments which will be performed on the Space Station.

  18. An expert system concept for autonomous spacecraft energy management

    SciTech Connect

    Imamura, M.S.; Dietrich, E.

    1983-08-01

    This paper presents a concept for an on-board spacecraft energy management system utilizing an expert systems approach. The energy management system continuously monitors and predicts the power capability of the spacecraft power subsystem, determines the overall electrical load profile, defines necessary changes to the initial equipment timeline, and implements new mission timeline and electrical load sequencing activities with little or no ground intervention. The system is intended to not only permit continued spacecraft operation in a degraded power subsystem state due to internal or external causes, but also to significantly optimize mission operation via maximum utilization of available power. The paper discusses the present state of the art of artificial intelligence technology and why the expert system is an attractive option to automate the energy management system for high power spacecraft.

  19. Overcoming deficiencies of the rule-based medical expert system.

    PubMed

    Hughes, C A; Gose, E E; Roseman, D L

    1990-05-01

    One of the current deficiencies of the rule-based expert system is its static nature. As these systems are applied to medicine, this shortcoming becomes accentuated by: the rapid speed at which new knowledge is generated, the regional differences associated with the expression of many diseases, and the rate at which patient demographics and disease incidence change over time. This research presents a solution to the static nature of the rule-based expert system by proposing a hybrid system. This system consists of an expert system and a statistical analysis system linked to a patient database. The additional feature of a rule base manager which initiates automatic database analysis to refresh the statistical correlation of each rule ensures a dynamic, current, statistically accurate rule base. The philosophical differences between data and knowledge are also addressed as they apply to this type of hybrid system. The system is then used to generate four rule bases from different knowledge sources. These rule bases are then compared. PMID:2401135

  20. An expert system for sensor data validation and malfunction detection

    SciTech Connect

    Hashemi, S.; Hajek, B.K.; Miller, D.W.

    1987-01-01

    Nuclear power plant operation and monitoring in general is a complex task which requires a large number of sensors, alarms and displays. At any instant in time, the operator is required to make a judgment about the state of the plant and to react accordingly. During abnormal situations, operators are further burdened with time constraints. The possibility of an undetected faulty instrumentation line, adds to the complexity of operators' reasoning tasks. Failure of human operators to cope with the conceptual complexity of abnormal situations often leads to more serious malfunctions and further damages to plant (TMI-2 as an example). During these abnormalities, operators rely on the information provided by the plant sensors and associated alarms. Their usefulness however, is quickly diminished by their large number and the extremely difficult task of interpreting and comprehending the information provided by them. The need for an aid to assist the operator in interpreting the available data and diagnosis of problems is obvious. Recent work at the Ohio State University Laboratory of Artificial Intelligence Research (LAIR) and the nuclear engineering program has concentrated on the problem of diagnostic expert systems performance and their applicability to the nuclear power plant domain. There has also been concern about the diagnostic expert systems performance when using potentially invalid sensor data. Because of this research, an expert system has been developed that can perform diagnostic problem solving despite the existence of some conflicting data in the domain. This work has resulted in enhancement of a programming tool, that allows domain experts to create a diagnostic system that will be to some degree, tolerant of bad data while performing diagnosis. This expert system is described here.

  1. Expert System Control of Plant Growth in an Enclosed Space

    NASA Technical Reports Server (NTRS)

    May, George; Lanoue, Mark; Bathel, Matthew; Ryan, Robert E.

    2008-01-01

    The Expert System is an enclosed, controlled environment for growing plants, which incorporates a computerized, knowledge-based software program that is designed to capture the knowledge, experience, and problem-solving skills of one or more human experts in a particular discipline. The Expert System is trained to analyze crop/plant status, to monitor the condition of the plants and the environment, and to adjust operational parameters to optimize the plant-growth process. This system is intended to provide a way to remotely control plant growth with little or no human intervention. More specifically, the term control implies an autonomous method for detecting plant states such as health (biomass) or stress and then for recommending and implementing cultivation and/or remediation to optimize plant growth and to minimize consumption of energy and nutrients. Because of difficulties associated with delivering energy and nutrients remotely, a key feature of this Expert System is its ability to minimize this effort and to achieve optimum growth while taking into account the diverse range of environmental considerations that exist in an enclosed environment. The plant-growth environment for the Expert System could be made from a variety of structures, including a greenhouse, an underground cavern, or another enclosed chamber. Imaging equipment positioned within or around the chamber provides spatially distributed crop/plant-growth information. Sensors mounted in the chamber provide data and information pertaining to environmental conditions that could affect plant development. Lamps in the growth environment structure supply illumination, and other additional equipment in the chamber supplies essential nutrients and chemicals.

  2. Application of fuzzy expert systems for EOR project risk analysis

    SciTech Connect

    Ting-Horng, Chung; Carroll, H.B.; Lindsey, R.

    1995-12-31

    This work describes a new method for enhanced oil recovery (EOR) project preassessment. Instead of using the conventional costly simulation approach, a fuzzy expert system was developed. A database of EOR project costs and oil prices of the past decades was incorporated into the expert system. The EOR project risk-analysis includes three stages: (1) preliminary screening of EOR methods, (2) field performance estimation, and (3) economic analysis. Since this fuzzy expert system has incorporated both implemented EOR technology and experts` experience, it thus reduces the requirements of massive laboratory and field data for input. Estimates of displacement efficiency (E{sub d}) and sweep efficiency (E{sub v}) were formulated for each EOR process. E{sub d} and E{sub v} were treated as fuzzy variables. The overall recovery efficiency is evaluated from the product of Ed and Ev using fuzzy set arithmetic. Economic analysis is based on the estimated recovery efficiency, residual oil inplace, oil price, and operating costs. Examples of the application of the developed method for a CO{sub 2}-flooding project analysis is presented.

  3. A Model Expert System For Machine Failure Diagnosis (MED)

    NASA Astrophysics Data System (ADS)

    Liqun, Yin

    1987-05-01

    MED is a model expert system for machine failure diagnosis. MED can help the repairer quickly determine milling machine electrical failure. The key points in MED are a simple method to deal with the "subsequent visit" problem in machine failure diagnosis, a weighted list to interfere in the control of AGENDA to imitate an expert's continuous thinking process and to keep away erratic questioning and problem running away caused by probabilistic reasoning, the structuralized AGENDA, the characteristics of machine failure diagnosis and people's thinking pattern in faulure diagnosis. The structuralized AGENDA gives an idea to supply a more powerful as well as flexible control strategy in best-first search by using AGENDA. The "subsequent visit" problem is a very complicated task to solve, it will be convenient to deal with it by using a simple method to keep from consuming too much time in urgent situations. Weighted list also gives a method to improve control in inference of expert system. The characteristics of machine failure diagnosis and people's thinking pattern are both important for building a machine failure diagnosis expert system. When being told failure phenomena, MED can determine failure causes through dialogue. MED is written in LISP and run in UNIVAC 1100/10 and IBM PC/XT computers. The average diagnosis time per failure is 11 seconds to CPU, 2 minites to terminal operation, and 11 minites to a skilful repairer.

  4. Exploiting expert systems in cardiology: a comparative study.

    PubMed

    Economou, George-Peter K; Sourla, Efrosini; Stamatopoulou, Konstantina-Maria; Syrimpeis, Vasileios; Sioutas, Spyros; Tsakalidis, Athanasios; Tzimas, Giannis

    2015-01-01

    An improved Adaptive Neuro-Fuzzy Inference System (ANFIS) in the field of critical cardiovascular diseases is presented. The system stems from an earlier application based only on a Sugeno-type Fuzzy Expert System (FES) with the addition of an Artificial Neural Network (ANN) computational structure. Thus, inherent characteristics of ANNs, along with the human-like knowledge representation of fuzzy systems are integrated. The ANFIS has been utilized into building five different sub-systems, distinctly covering Coronary Disease, Hypertension, Atrial Fibrillation, Heart Failure, and Diabetes, hence aiding doctors of medicine (MDs), guide trainees, and encourage medical experts in their diagnoses centering a wide range of Cardiology. The Fuzzy Rules have been trimmed down and the ANNs have been optimized in order to focus into each particular disease and produce results ready-to-be applied to real-world patients. PMID:25417018

  5. Requirements specification for nickel cadmium battery expert system

    NASA Technical Reports Server (NTRS)

    1986-01-01

    The requirements for performance, design, test, and qualification of a computer program identified as NICBES, Nickel Cadmium Battery Expert System, is established. The specific spacecraft power system configuration selected was the Hubble Space Telescope (HST) Electrical Power System (EPS) Testbed. Power for the HST comes from a system of 13 Solar Panel Arrays (SPAs) linked to 6 Nickel Cadmium Batteries which are connected to 3 Busses. An expert system, NICBES, will be developed at Martin Marietta Aerospace to recognize a testbed anomaly, identify the malfunctioning component and recommend a course of action. Besides fault diagnosis, NICBES will be able to evaluate battery status, give advice on battery status and provide decision support for the operator. These requirements are detailed.

  6. Spacelab Life Sciences-1 electrical diagnostic expert system

    NASA Technical Reports Server (NTRS)

    Kao, C. Y.; Morris, W. S.

    1989-01-01

    The Spacelab Life Sciences-1 (SLS-1) Electrical Diagnostic (SLED) expert system is a continuous, real time knowledge-based system to monitor and diagnose electrical system problems in the Spacelab. After fault isolation, the SLED system provides corrective procedures and advice to the ground-based console operator. The SLED system updates its knowledge about the status of Spacelab every 3 seconds. The system supports multiprocessing of malfunctions and allows multiple failures to be handled simultaneously. Information which is readily available via a mouse click includes: general information about the system and each component, the electrical schematics, the recovery procedures of each malfunction, and an explanation of the diagnosis.

  7. Spacelab Life Sciences-1 electrical diagnostics expert system

    NASA Technical Reports Server (NTRS)

    Kao, Cheng Y.; Morris, William S.

    1989-01-01

    The Spacelab Life Sciences-1 (SLS-1) Electrical Diagnostic (SLED) expert system is a continuous real time knowledge-based system to monitor and diagnose electrical system problems in the Spacelab. After fault isolation, the SLED system provides corrective procedures and advice to the ground-based console operator. The SLED system updates its knowledge about the status of Spacelab every 3 seconds. The system supports multiprocessing of malfunctions and allows multiple failures to be handled simultaneously. Information which is readily available via a mouse click includes: general information about the system and each component, the electrical schematics, the recovery procedures of each malfunction, and an explanation of the diagnosis.

  8. Development of the Diagnostic Expert System for Tea Processing

    NASA Astrophysics Data System (ADS)

    Yoshitomi, Hitoshi; Yamaguchi, Yuichi

    A diagnostic expert system for tea processing which can presume the cause of the defect of the processed tea was developed to contribute to the improvement of tea processing. This system that consists of some programs can be used through the Internet. The inference engine, the core of the system adopts production system which is well used on artificial intelligence, and is coded by Prolog as the artificial intelligence oriented language. At present, 176 rules for inference have been registered on this system. The system will be able to presume better if more rules are added to the system.

  9. Ground terminal expert (GTEX). Part 2: Expert system diagnostics for a 30/20 Gigahertz satellite transponder

    NASA Technical Reports Server (NTRS)

    Durkin, John; Schlegelmilch, Richard; Tallo, Donald

    1992-01-01

    A research effort was undertaken to investigate how expert system technology could be applied to a satellite communications system. The focus of the expert system is the satellite earth station. A proof of concept expert system called the Ground Terminal Expert (GTEX) was developed at the University of Akron in collaboration with the NASA Lewis Research Center. With the increasing demand for satellite earth stations, maintenance is becoming a vital issue. Vendors of such systems will be looking for cost effective means of maintaining such systems. The objective of GTEX is to aid in diagnosis of faults occurring with the digital earth station. GTEX was developed on a personal computer using the Automated Reasoning Tool for Information Management (ART-IM) developed by the Inference Corporation. Developed for the Phase 2 digital earth station, GTEX is a part of the Systems Integration Test and Evaluation (SITE) facility located at the NASA Lewis Research Center.

  10. Expert system shell to reason on large amounts of data

    NASA Technical Reports Server (NTRS)

    Giuffrida, Gionanni

    1994-01-01

    The current data base management systems (DBMS's) do not provide a sophisticated environment to develop rule based expert systems applications. Some of the new DBMS's come with some sort of rule mechanism; these are active and deductive database systems. However, both of these are not featured enough to support full implementation based on rules. On the other hand, current expert system shells do not provide any link with external databases. That is, all the data are kept in the system working memory. Such working memory is maintained in main memory. For some applications the reduced size of the available working memory could represent a constraint for the development. Typically these are applications which require reasoning on huge amounts of data. All these data do not fit into the computer main memory. Moreover, in some cases these data can be already available in some database systems and continuously updated while the expert system is running. This paper proposes an architecture which employs knowledge discovering techniques to reduce the amount of data to be stored in the main memory; in this architecture a standard DBMS is coupled with a rule-based language. The data are stored into the DBMS. An interface between the two systems is responsible for inducing knowledge from the set of relations. Such induced knowledge is then transferred to the rule-based language working memory.

  11. Expert Systems, Job Aids, and the Future of Instructional Technology; and Decision Tables, the Poor Person's Answer to "Expert Systems."

    ERIC Educational Resources Information Center

    Harmon, Paul; Pipe, Peter

    1986-01-01

    Describes design and presents examples of industrial use of small expert systems and guidelines for choosing problems which lend themselves to small tool solutions. Use of microcomputer facilitated decision tables to diagnose and categorize people, things, and issues is suggested, and development of three decision table formats is described. (MBR)

  12. Sensor-based fault diagnosis in a flight expert system

    NASA Technical Reports Server (NTRS)

    Ali, M.; Scharnhorst, D. A.

    1985-01-01

    A prototype of a knowledge-based flight expert system (FLES) has been developed to assist airplane pilots in monitoring, analyzing, and diagnosing faults and to provide support in reducing the pilot's own mistakes. A sensor simulation model has been developed to provide FLES with the airplane status information during the diagnostic process. The simulator is based partly on the Advanced Concept System (ACS), a future-generation airplane, and partly on the Boeing 737, an existing airplane. The architecture of FLES contains several subsystems. One of the major subsystems performs fault diagnosis in the electrical system of the ACS. This paper describes the mechanism and functionality of the automatic diagnosis performed in this expert system.

  13. PVEX: An expert system for producibility/value engineering

    NASA Technical Reports Server (NTRS)

    Lam, Chun S.; Moseley, Warren

    1991-01-01

    PVEX is described as an expert system that solves the problem of selection of the material and process in missile manufacturing. The producibility and the value problem has been deeply studied in the past years, and was written in dBase III and PROLOG before. A new approach is presented in that the solution is achieved by introducing hypothetical reasoning, heuristic criteria integrated with a simple hypertext system and shell programming. PVEX combines KMS with Unix scripts which graphically depicts decision trees. The decision trees convey high level qualitative problem solving knowledge to users, and a stand-alone help facility and technical documentation is available through KMS. The system developed is considerably less development costly than any other comparable expert system.

  14. MOM: A meteorological data checking expert system in CLIPS

    NASA Technical Reports Server (NTRS)

    Odonnell, Richard

    1990-01-01

    Meteorologists have long faced the problem of verifying the data they use. Experience shows that there is a sizable number of errors in the data reported by meteorological observers. This is unacceptable for computer forecast models, which depend on accurate data for accurate results. Most errors that occur in meteorological data are obvious to the meteorologist, but time constraints prevent hand-checking. For this reason, it is necessary to have a 'front end' to the computer model to ensure the accuracy of input. Various approaches to automatic data quality control have been developed by several groups. MOM is a rule-based system implemented in CLIPS and utilizing 'consistency checks' and 'range checks'. The system is generic in the sense that it knows some meteorological principles, regardless of specific station characteristics. Specific constraints kept as CLIPS facts in a separate file provide for system flexibility. Preliminary results show that the expert system has detected some inconsistencies not noticed by a local expert.

  15. [MEDRISK--an expert system for medical risk assessment].

    PubMed

    Mayer-Ohly, E; Regenauer, A

    1995-10-01

    The Munich Reinsurance Company has developed a rule-based expert system for assessing substandard risk in life, disability and accidental death benefit. It is one of the most comprehensive medical expert systems yet conceived and currently includes entries for over 7500 impairment terms. Based on the most up-to-date insurance medical knowledge MEDRISK allows underwriters, irrespective of their level of experience, to process both simple and highly complex cases. The system which takes account of the interactive effect that can exist between different impairments as well as the influence which occupational factors can exert, always produces consistent and case-specific decisions. The number of impairments and types of insurance included in MEDRISK can be expanded. After tests at Munich Re and at a number of insurance companies, the system ist now ready to be launched in German speaking markets. PMID:7483188

  16. The Expert System Programme of the European Space Agency

    NASA Astrophysics Data System (ADS)

    Lafay, J. F.; Allard, F.

    1992-08-01

    ESA's Expert System Demonstration (ESD) program is discussed in terms of its goals, structure, three-phase approach, and initial results. ESD is intended to demonstrate the benefits of AI and knowledge-based systems for in-orbit infrastructures by developing a strategic technology to contribute to ESA missions. Three phases were defined for: (1) program definition and review of existing work; (2) demonstration of applications prototypes; and (3) the development of operational systems from successful prototypes. Applications of 16 proposed expert-system candidates are grouped into payload-engineering and crew/operations categories. The candidates are to be evaluated in terms of their potential contribution to strategic goals such as improving scientific return and automating operator functions to eliminate human error.

  17. Hybrid expert system implementation to determine core reload patterns

    SciTech Connect

    Greek, K.J.; Robinson, A.H.

    1989-01-01

    Determining reactor reload fuel patterns is a computationally intensive problem solving process for which automation can be of significant benefit. Often much effort is expended in the search for an optimal loading. While any modern programming language could be used to automate solution, the specialized tools of artificial intelligence (AI) are the most efficient means of introducing the fuel management expert's knowledge into the search for an optimum reload pattern. Prior research in pressurized water reactor refueling strategies developed FORTRAN programs that automated an expert's basic knowledge to direct a search for an acceptable minimum peak power loading. The dissatisfaction with maintenance of compiled knowledge in FORTRAN programs has served as the motivation for the development of the SHUFFLE expert system. SHUFFLE is written in Smalltalk, an object-oriented programming language, and evaluates loadings as it generates them using a two-group, two-dimensional nodal power calculation compiled in a personal computer-based FORTRAN. This paper reviews the object-oriented representation developed to solve the core reload problem with an expert system tool and its operating prototype, SHUFFLE.

  18. Fault isolation detection expert (FIDEX). Part 1: Expert system diagnostics for a 30/20 Gigahertz satellite transponder

    NASA Technical Reports Server (NTRS)

    Durkin, John; Schlegelmilch, Richard; Tallo, Donald

    1992-01-01

    LeRC has recently completed the design of a Ka-band satellite transponder system, as part of the Advanced Communication Technology Satellite (ACTS) System. To enhance the reliability of this satellite, NASA funded the University of Akron to explore the application of an expert system to provide the transponder with an autonomous diagnosis capability. The results of this research was the development of a prototype diagnosis expert system called FIDEX (fault-isolation and diagnosis expert). FIDEX is a frame-based expert system that was developed in the NEXPERT Object development environment by Neuron Data, Inc. It is a MicroSoft Windows version 3.0 application, and was designed to operate on an Intel i80386 based personal computer system.

  19. TOPEX/Poseidon precision orbit determination production and expert system

    NASA Technical Reports Server (NTRS)

    Putney, Barbara; Zelensky, Nikita; Klosko, Steven

    1993-01-01

    TOPEX/Poseidon (T/P) is a joint mission between NASA and the Centre National d'Etudes Spatiales (CNES), the French Space Agency. The TOPEX/Poseidon Precision Orbit Determination Production System (PODPS) was developed at Goddard Space Flight Center (NASA/GSFC) to produce the absolute orbital reference required to support the fundamental ocean science goals of this satellite altimeter mission within NASA. The orbital trajectory for T/P is required to have a RMS accuracy of 13 centimeters in its radial component. This requirement is based on the effective use of the satellite altimetry for the isolation of absolute long-wavelength ocean topography important for monitoring global changes in the ocean circulation system. This orbit modeling requirement is at an unprecedented accuracy level for this type of satellite. In order to routinely produce and evaluate these orbits, GSFC has developed a production and supporting expert system. The PODPS is a menu driven system allowing routine importation and processing of tracking data for orbit determination, and an evaluation of the quality of the orbit so produced through a progressive series of tests. Phase 1 of the expert system grades the orbit and displays test results. Later phases undergoing implementation, will prescribe corrective actions when unsatisfactory results are seen. This paper describes the design and implementation of this orbit determination production system and the basis for its orbit accuracy assessment within the expert system.

  20. Expert system for online surveillance of nuclear reactor coolant pumps

    DOEpatents

    Gross, Kenny C.; Singer, Ralph M.; Humenik, Keith E.

    1993-01-01

    An expert system for online surveillance of nuclear reactor coolant pumps. This system provides a means for early detection of pump or sensor degradation. Degradation is determined through the use of a statistical analysis technique, sequential probability ratio test, applied to information from several sensors which are responsive to differing physical parameters. The results of sequential testing of the data provide the operator with an early warning of possible sensor or pump failure.

  1. The development of an MSS satellite imagery classification expert system

    NASA Technical Reports Server (NTRS)

    Engle, S. W.

    1985-01-01

    Unsupervised image classification of Landsat MSS imagery entails a significant part of the remote sensing, image analysis effort. Expert systems, a technology developed in the field of artificial intelligence, offers the potential to automate this process, thus greatly increasing the efficiency with which an analyst can perform unsupervised image classification and making the knowledge of the image analyst available to a community of nonexperts. Such a system, under development at the NASA/Ames Research Center, is described and planned enhancements are discussed.

  2. A knowledge-based expert system for inferring vegetation characteristics

    NASA Technical Reports Server (NTRS)

    Kimes, Daniel S.; Harrison, Patrick R.; Ratcliffe, P. A.

    1991-01-01

    A prototype knowledge-based expert system VEG is presented that focuses on extracting spectral hemispherical reflectance using any combination of nadir and/or directional reflectance data as input. The system is designed to facilitate expansion to handle other inferences regarding vegetation properties such as total hemispherical reflectance, leaf area index, percent ground cover, phosynthetic capacity, and biomass. This approach is more robust and accurate than conventional extraction techniques previously developed.

  3. An expert systems application to space base data processing

    NASA Technical Reports Server (NTRS)

    Babb, Stephen M.

    1988-01-01

    The advent of space vehicles with their increased data requirements are reflected in the complexity of future telemetry systems. Space based operations with its immense operating costs will shift the burden of data processing and routine analysis from the space station to the Orbital Transfer Vehicle (OTV). A research and development project is described which addresses the real time onboard data processing tasks associated with a space based vehicle, specifically focusing on an implementation of an expert system.

  4. Melatonin is a redundant entraining signal in the rat circadian system.

    PubMed

    Houdek, Pavel; Nováková, Marta; Polidarová, Lenka; Sládek, Martin; Sumová, Alena

    2016-07-01

    The role of melatonin in maintaining proper function of the circadian system has been proposed but very little evidence for such an effect has been provided. To ascertain the role, the aim of the study was to investigate impact of long-term melatonin absence on regulation of circadian system. The parameters of behavior and circadian clocks of rats which were devoid of the melatonin signal due to pinealectomy (PINX) for more than one year were compared with those of intact age-matched controls. PINX led to a decrease in spontaneous locomotor activity and a shortening of the free-running period of the activity rhythm driven by the central clock in the suprachiasmatic nuclei (SCN) in constant darkness. However, the SCN-driven rhythms in activity and feeding were not affected and remained well entrained in the light/dark cycle. In contrast, in these conditions PINX had a significant effect on amplitudes of the clock gene expression rhythms in the duodenum and also partially in the liver. These results demonstrate the significant impact of long-term melatonin absence on period of the central clock in the SCN and the amplitudes of the peripheral clocks in duodenum and liver and suggest that melatonin might be a redundant but effective endocrine signal for these clocks. PMID:27167607

  5. Lighting and optics expert system for machine vision

    NASA Astrophysics Data System (ADS)

    Novini, Amir R.

    1991-03-01

    Machine Vision and the field of Artificial Intelligence are both new technologies which hive evolved mainly within the past decade with the growth of computers and microchips. And although research continues both have emerged from tF experimental state to industrial reality. Today''s machine vision systEns are solving thousands of manufacturing problems in various industries and the impact of Artificial Intelligence and more specifically the ue of " Expert Systems" in industry is also being realized. This pape will examine how the two technologies can cross paths and how an E7ert System can become an important part of an overall machine vision solution. An actual example of a development of an Expert System that helps solve machine vision lighting and optics problems will be discussed. The lighting and optics xpert System was developed to assist the end user to configure the " Front End" of a vision system to help solve the overall machine vision problem more effectively since lack of attention to lighting and optics has caused many failures of this technology. Other areas of machine vision technology where Expert Systems could apply will also be ciscussed.

  6. Results From The First Interactive Scientific Expert System In Space

    NASA Technical Reports Server (NTRS)

    Groleau, Nicolas; Frainier, Richard J.; Friedland, Peter (Technical Monitor)

    1994-01-01

    We describe recent work on automation and support of science experiments on the Space Shuttle. PI-in-a-Box, the first interactive expert system for scientific support, was flown onboard STS-58 in October 1993. It was designed to help astronauts perform better science in space by providing expert-level advice in real-time. The system provides help with 'technician' tasks such as data acquisition, data quality monitoring, and diagnostic, troubleshooting and repair. The system also performs 'expert' reasoning on the scientific model and experiment steps scheduling. It can make scheduling recommendations based on hardware status, time available, and agreement between predictions and flight data. The system was successfully deployed and used throughout the mission. Most of the 'technician' skills of the system were used with success. The scientific model study performed correctly, but we believe the results were not exploited by the astronauts because of Spacelab operational pressures. Also, portions of the system were designed around rigid schedule constraints that were essentially relaxed during the mission. This version was tailored to a specific vestibular experiment known as the 'rotating dome'. We are currently expanding our effort in various scientific (other life and microgravity sciences experiments) and technological directions (integrated telescience, astronaut science advisor, and autonomous control).

  7. Results from the First Interactive Scientific Expert System in Space

    NASA Technical Reports Server (NTRS)

    Groleau, Nicolas; Frainier, Richard J.; Friedland, Peter (Technical Monitor)

    1994-01-01

    We describe recent work on automation and support of science experiments on the Space Shuttle. PI-in-a-Box, the first interactive expert system for scientific support, was flown onboard STS-58 in October 1993. It was designed to help astronauts perform better science in space by providing expert-level advice in real-time. The system provides help with "technician" tasks such as data acquisition, data quality monitoring, and diagnostic, troubleshooting and repair. The system also performs "expert" reasoning on the scientific model and experiment steps scheduling. It can make scheduling recommendations based on hardware status, time available, and agreement between predictions and flight data. The system was successfully deployed and used throughout the mission. Most of the "technician" skills of the system were used with success. The scientific model study performed correctly, but we believe the results were not exploited by the astronauts because of Spacelab operational pressures. Also, portions of the system were designed around rigid schedule constraints that were essentially relaxed during the mission. This version was tailored to a specific vestibular experiment known as the "rotating dome". We are currently expanding our effort in various scientific (other life and microgravity sciences experiments) and technological directions (integrated telescience, astronaut science advisor, and autonomous control).

  8. GERIREX - growing a second generation medical expert system

    SciTech Connect

    Kocur, J. Jr.; Suh, S.C.

    1996-12-31

    This article describes GERIREX, a medical expert system as the core module of an integrated system for total management of a medical practice. GERIREX is currently a first-generation consultant in the domain of prescribing for the geriatric patient with multiple ailments. Employing rule and objective probabilistic knowledge representations, the system performs at the near-expert level, correctly ranking single and multiple drug therapy for hypertension and/or congestive heart failure in the presence of between two and seven of 18 common accompanying or underlying conditions. GERIREX creates permanent consultation records and can access patient information from existing databases. System requirements are met by very modest PCs, yet power, speed, flexibility, and ease of use rival or exceed those of many other systems. GERIREX interfaces with a variety of configurations and applications, including text, spreadsheets, databases, and executables, to fit in with current plans to upgrade to a second generation system, providing a degree of self-maintenance through intelligent parsing of a drug data source such as the Physicians` Desk Reference (PDR - CDROM version). Another option under consideration is developing neural networks to both replace the current knowledge base, and to embody the rationale employed by the medical expert in evaluating drug data for treatment selection. In this version, the current drug database would be used as warning data for the network tasked with adding new drugs to the drug database, imitating the process whereby a physician determines their personal arsenal from among the wide range of available options.

  9. Index : A Rule Based Expert System For Computer Network Maintenance

    NASA Astrophysics Data System (ADS)

    Chaganty, Srinivas; Pitchai, Anandhi; Morgan, Thomas W.

    1988-03-01

    Communications is an expert intensive discipline. The application of expert systems for maintenance of large and complex networks, mainly as an aid in trouble shooting, can simplify the task of network management. The important steps involved in troubleshooting are fault detection, fault reporting, fault interpretation and fault isolation. At present, Network Maintenance Facilities are capable of detecting and reporting the faults to network personnel. Fault interpretation refers to the next step in the process, which involves coming up with reasons for the failure. Fault interpretation can be characterized in two ways. First, it involves such a diversity of facts that it is difficult to predict. Secondly, it embodies a wealth of knowledge in the form of network management personnel. The application of expert systems in these interpretive tasks is an important step towards automation of network maintenance. In this paper, INDEX (Intelligent Network Diagnosis Expediter), a rule based production system for computer network alarm interpretation is described. It acts as an intelligent filter for people analyzing network alarms. INDEX analyzes the alarms in the network and identifies proper maintenance action to be taken.The important feature of this production system is that it is data driven. Working memory is the principal data repository of production systems and its contents represent the current state of the problem. Control is based upon which productions match the constantly changing working memory elements. Implementation of the prototype is in OPS83. Major issues in rule based system development such as rule base organization, implementation and efficiency are discussed.

  10. An expert system for diagnosing environmentally induced spacecraft anomalies

    NASA Technical Reports Server (NTRS)

    Rolincik, Mark; Lauriente, Michael; Koons, Harry C.; Gorney, David

    1992-01-01

    A new rule-based, machine independent analytical tool was designed for diagnosing spacecraft anomalies using an expert system. Expert systems provide an effective method for saving knowledge, allow computers to sift through large amounts of data pinpointing significant parts, and most importantly, use heuristics in addition to algorithms, which allow approximate reasoning and inference and the ability to attack problems not rigidly defined. The knowledge base consists of over two-hundred (200) rules and provides links to historical and environmental databases. The environmental causes considered are bulk charging, single event upsets (SEU), surface charging, and total radiation dose. The system's driver translates forward chaining rules into a backward chaining sequence, prompting the user for information pertinent to the causes considered. The use of heuristics frees the user from searching through large amounts of irrelevant information and allows the user to input partial information (varying degrees of confidence in an answer) or 'unknown' to any question. The modularity of the expert system allows for easy updates and modifications. It not only provides scientists with needed risk analysis and confidence not found in algorithmic programs, but is also an effective learning tool, and the window implementation makes it very easy to use. The system currently runs on a Micro VAX II at Goddard Space Flight Center (GSFC). The inference engine used is NASA's C Language Integrated Production System (CLIPS).

  11. Adaptive control with an expert system based supervisory level. Thesis

    NASA Technical Reports Server (NTRS)

    Sullivan, Gerald A.

    1991-01-01

    Adaptive control is presently one of the methods available which may be used to control plants with poorly modelled dynamics or time varying dynamics. Although many variations of adaptive controllers exist, a common characteristic of all adaptive control schemes, is that input/output measurements from the plant are used to adjust a control law in an on-line fashion. Ideally the adjustment mechanism of the adaptive controller is able to learn enough about the dynamics of the plant from input/output measurements to effectively control the plant. In practice, problems such as measurement noise, controller saturation, and incorrect model order, to name a few, may prevent proper adjustment of the controller and poor performance or instability result. In this work we set out to avoid the inadequacies of procedurally implemented safety nets, by introducing a two level control scheme in which an expert system based 'supervisor' at the upper level provides all the safety net functions for an adaptive controller at the lower level. The expert system is based on a shell called IPEX, (Interactive Process EXpert), that we developed specifically for the diagnosis and treatment of dynamic systems. Some of the more important functions that the IPEX system provides are: (1) temporal reasoning; (2) planning of diagnostic activities; and (3) interactive diagnosis. Also, because knowledge and control logic are separate, the incorporation of new diagnostic and treatment knowledge is relatively simple. We note that the flexibility available in the system to express diagnostic and treatment knowledge, allows much greater functionality than could ever be reasonably expected from procedural implementations of safety nets. The remainder of this chapter is divided into three sections. In section 1.1 we give a detailed review of the literature in the area of supervisory systems for adaptive controllers. In particular, we describe the evolution of safety nets from simple ad hoc techniques, up

  12. Expert systems and advanced automation for space missions operations

    NASA Technical Reports Server (NTRS)

    Durrani, Sajjad H.; Perkins, Dorothy C.; Carlton, P. Douglas

    1990-01-01

    Increased complexity of space missions during the 1980s led to the introduction of expert systems and advanced automation techniques in mission operations. This paper describes several technologies in operational use or under development at the National Aeronautics and Space Administration's Goddard Space Flight Center. Several expert systems are described that diagnose faults, analyze spacecraft operations and onboard subsystem performance (in conjunction with neural networks), and perform data quality and data accounting functions. The design of customized user interfaces is discussed, with examples of their application to space missions. Displays, which allow mission operators to see the spacecraft position, orientation, and configuration under a variety of operating conditions, are described. Automated systems for scheduling are discussed, and a testbed that allows tests and demonstrations of the associated architectures, interface protocols, and operations concepts is described. Lessons learned are summarized.

  13. On the development of an expert system for wheelchair selection

    NASA Technical Reports Server (NTRS)

    Madey, Gregory R.; Bhansin, Charlotte A.; Alaraini, Sulaiman A.; Nour, Mohamed A.

    1994-01-01

    The presentation of wheelchairs for the Multiple Sclerosis (MS) patients involves the examination of a number of complicated factors including ambulation status, length of diagnosis, and funding sources, to name a few. Consequently, only a few experts exist in this area. To aid medical therapists with the wheelchair selection decision, a prototype medical expert system (ES) was developed. This paper describes and discusses the steps of designing and developing the system, the experiences of the authors, and the lessons learned from working on this project. Wheelchair Advisor, programmed in CLIPS, serves as diagnosis, classification, prescription, and training tool in the MS field. Interviews, insurance letters, forms, and prototyping were used to gain knowledge regarding the wheelchair selection problem. Among the lessons learned are that evolutionary prototyping is superior to the conventional system development life-cycle (SDLC), the wheelchair selection is a good candidate for ES applications, and that ES can be applied to other similar medical subdomains.

  14. MAESTRO -- A Model and Expert System Tuning Resource for Operators

    SciTech Connect

    Lager, D.L.; Brand, H.R.; Maurer, W.J.; Coffield, F.E.; Chambers, F.

    1989-01-01

    We have developed MAESTRO, a Model And Expert System Tuning Resource for Operators. It provides a unified software environment for optimizing the performance of large, complex machines, in particular the Advanced Test Accelerator and Experimental Test Accelerator at Lawrence Livermore National Laboratory. The system incorporates three approaches to tuning: a mouse-based manual interface to select and control magnets and to view displays of machine performance; an automation based on cloning the operator'' by implementing the strategies and reasoning used by the operator; an automation based on a simulator model which, when accurately matched to the machine, allows downloading of optimal sets of parameters and permits diagnosing errors in the beamline. The latter two approaches are based on the Artificial Intelligence technique known as Expert Systems. 4 refs., 4 figs.

  15. Encoding expert knowledge: A Bayesian diagnostic system for diesel generators

    SciTech Connect

    Bley, D.C.

    1991-01-01

    Developing computer systems to capture the knowledge of human experts offers new opportunities to electric utilities. Such systems become particularly attractive when technical expertise resides within a single individual, possibly nearing retirement, who has not otherwise passed along his important knowledge and though processes. An expert system model called the Bayesian diagnostic module (BMD) has been developed to aid plant personnel in diagnosing the causes of equipment failure. The BDM deals with uncertainty in a mathematically logical and rigorous way. If sufficient observables are provided as input, it can identify a single cause of failure with very high confidence. Given less complete information, the method degrades gracefully by advising operators about alternative causes of failure, including as estimate of the likelihood that each cause is the correct one. The complete theoretical foundation of the BDM is briefly summarized in this paper.

  16. An expert system for prediction of aquatic toxicity of contaminants

    USGS Publications Warehouse

    Hickey, James P.; Aldridge, Andrew J.; Passino, Dora R. May; Frank, Anthony M.

    1990-01-01

    The National Fisheries Research Center-Great Lakes has developed an interactive computer program in muLISP that runs on an IBM-compatible microcomputer and uses a linear solvation energy relationship (LSER) to predict acute toxicity to four representative aquatic species from the detailed structure of an organic molecule. Using the SMILES formalism for a chemical structure, the expert system identifies all structural components and uses a knowledge base of rules based on an LSER to generate four structure-related parameter values. A separate module then relates these values to toxicity. The system is designed for rapid screening of potential chemical hazards before laboratory or field investigations are conducted and can be operated by users with little toxicological background. This is the first expert system based on LSER, relying on the first comprehensive compilation of rules and values for the estimation of LSER parameters.

  17. A fuzzy expert system design for diagnosis of cancer

    NASA Astrophysics Data System (ADS)

    Sarode, Milindkumar V.; Deshmukh, Prashant R.

    2010-02-01

    Here a fuzzy expert system design for diagnosing, analyzing and learning purpose of the cancer diseases is described. For this process prostate specific antigen (PSA), age and prostate volume (PV) has been used as an input parameters and prostate cancer risk (PCR) as an output. This system allows determining if there is a need for the biopsy and it gives to user a range of the risk of the cancer diseases. It is observed that this system is rapid, economical, without risk than traditional diagnostic systems, has also a high reliability and can be used as learning system for medicine students.

  18. Expert system for on-board satellite scheduling and control

    NASA Technical Reports Server (NTRS)

    Barry, John M.; Sary, Charisse

    1988-01-01

    An Expert System is described which Rockwell Satellite and Space Electronics Division (S&SED) is developing to dynamically schedule the allocation of on-board satellite resources and activities. This expert system is the Satellite Controller. The resources to be scheduled include power, propellant and recording tape. The activities controlled include scheduling satellite functions such as sensor checkout and operation. The scheduling of these resources and activities is presently a labor intensive and time consuming ground operations task. Developing a schedule requires extensive knowledge of the system and subsystems operations, operational constraints, and satellite design and configuration. This scheduling process requires highly trained experts anywhere from several hours to several weeks to accomplish. The process is done through brute force, that is examining cryptic mnemonic data off line to interpret the health and status of the satellite. Then schedules are formulated either as the result of practical operator experience or heuristics - that is rules of thumb. Orbital operations must become more productive in the future to reduce life cycle costs and decrease dependence on ground control. This reduction is required to increase autonomy and survivability of future systems. The design of future satellites require that the scheduling function be transferred from ground to on board systems.

  19. Howard University Energy Expert Systems Institute Summer Program (EESI)

    NASA Technical Reports Server (NTRS)

    Momoh, James A.; Chuku, Arunsi; Abban, Joseph

    1996-01-01

    Howard University, under the auspices of the Center for Energy Systems and Controls runs the Energy Expert Systems Institute (EESI) summer outreach program for high school/pre-college minority students. The main objectives are to introduce precollege minority students to research in the power industry using modern state-of-the-art technology such as Expert Systems, Fuzzy Logic and Artificial Neural Networks; to involve minority students in space power management, systems and failure diagnosis; to generate interest in career options in electrical engineering; and to experience problem-solving in a teamwork environment consisting of faculty, senior research associates and graduate students. For five weeks the students are exposed not only to the exciting experience of college life, but also to the inspiring field of engineering, especially electrical engineering. The program consists of lectures in the fundamentals of engineering, mathematics, communication skills and computer skills. The projects are divided into mini and major. Topics for the 1995 mini projects were Expert Systems for the Electric Bus and Breast Cancer Detection. Topics on the major projects include Hybrid Electric Vehicle, Solar Dynamics and Distribution Automation. On the final day, designated as 'EESI Day' the students did oral presentations of their projects and prizes were awarded to the best group. The program began in the summer of 1993. The reaction from the students has been very positive. The program also arranges field trips to special places of interest such as the NASA Goddard Space Center.

  20. Expert systems for automated correlation and interpretation of wireline logs

    USGS Publications Warehouse

    Olea, R.A.

    1994-01-01

    CORRELATOR is an interactive computer program for lithostratigraphic correlation of wireline logs able to store correlations in a data base with a consistency, accuracy, speed, and resolution that are difficult to obtain manually. The automatic determination of correlations is based on the maximization of a weighted correlation coefficient using two wireline logs per well. CORRELATOR has an expert system to scan and flag incongruous correlations in the data base. The user has the option to accept or disregard the advice offered by the system. The expert system represents knowledge through production rules. The inference system is goal-driven and uses backward chaining to scan through the rules. Work in progress is used to illustrate the potential that a second expert system with a similar architecture for interpreting dip diagrams could have to identify episodes-as those of interest in sequence stratigraphy and fault detection- and annotate them in the stratigraphic column. Several examples illustrate the presentation. ?? 1994 International Association for Mathematical Geology.

  1. Debugging expert systems using a dynamically created hypertext network

    NASA Technical Reports Server (NTRS)

    Boyle, Craig D. B.; Schuette, John F.

    1991-01-01

    The labor intensive nature of expert system writing and debugging motivated this study. The hypothesis is that a hypertext based debugging tool is easier and faster than one traditional tool, the graphical execution trace. HESDE (Hypertext Expert System Debugging Environment) uses Hypertext nodes and links to represent the objects and their relationships created during the execution of a rule based expert system. HESDE operates transparently on top of the CLIPS (C Language Integrated Production System) rule based system environment and is used during the knowledge base debugging process. During the execution process HESDE builds an execution trace. Use of facts, rules, and their values are automatically stored in a Hypertext network for each execution cycle. After the execution process, the knowledge engineer may access the Hypertext network and browse the network created. The network may be viewed in terms of rules, facts, and values. An experiment was conducted to compare HESDE with a graphical debugging environment. Subjects were given representative tasks. For speed and accuracy, in eight of the eleven tasks given to subjects, HESDE was significantly better.

  2. SoxNeuro orchestrates central nervous system specification and differentiation in Drosophila and is only partially redundant with Dichaete

    PubMed Central

    2014-01-01

    Background Sox proteins encompass an evolutionarily conserved family of transcription factors with critical roles in animal development and stem cell biology. In common with vertebrates, the Drosophila group B proteins SoxNeuro and Dichaete are involved in central nervous system development, where they play both similar and unique roles in gene regulation. Sox genes show extensive functional redundancy across metazoans, but the molecular basis underpinning functional compensation mechanisms at the genomic level are currently unknown. Results Using a combination of genome-wide binding analysis and gene expression profiling, we show that SoxNeuro directs embryonic neural development from the early specification of neuroblasts through to the terminal differentiation of neurons and glia. To address the issue of functional redundancy and compensation at a genomic level, we compare SoxNeuro and Dichaete binding, identifying common and independent binding events in wild-type conditions, as well as instances of compensation and loss of binding in mutant backgrounds. Conclusions We find that early aspects of group B Sox functions in the central nervous system, such as stem cell maintenance and dorsoventral patterning, are highly conserved. However, in contrast to vertebrates, we find that Drosophila group B1 proteins also play prominent roles during later aspects of neural morphogenesis. Our analysis of the functional relationship between SoxNeuro and Dichaete uncovers evidence for redundant and independent functions for each protein, along with unexpected examples of compensation and interdependency, thus providing new insights into the general issue of transcription factor functional redundancy. PMID:24886562

  3. Get Better Resolution by Throwing Away Light: Non-Redundant Masking in Optical Systems

    NASA Astrophysics Data System (ADS)

    Greenbaum, Alexandra; Sivaramakrishnan, A.

    2011-05-01

    Astronomers strive for clearer images with finer detail, better resolution. Particularly with the last decade's increasing interest in exoplanets, the burden lies on the instruments to provide the eye into the backyard of other planetary systems. Non-redundant Masking provides over two-fold better resolution than traditional imaging, acting as a multi-baseline intereferometer instead of a circular aperture. Analyzing intereferometric data is achieved through the science of Fraunhoffer diffraction (optics) and Fourier transforms. Preliminary analysis of near-IR data from the Project 1640 Integral Field Spectrograph (Hinkley et al. 2009) on the Palomar Hale yields a directly detected companion in a known spectroscopic binary. Additionally, laboratory optics of faint companions to be imaged on AMNH's NRM testbed with a mask designed for the JWST FGS Tunable Filter Imager were developed. A promising two-pinhole method of light attenuation, where no additional polarization or scattering is introduced, was modeled theoretically and implemented in hardware. This research was funded by the NSF REU program at the American Museum of Natural History summer 2010.

  4. Equalization in redundant channels

    NASA Technical Reports Server (NTRS)

    Tulpule, Bhalchandra R. (Inventor); Collins, Robert E. (Inventor); Cominelli, Donald F. (Inventor); O'Neill, Richard D. (Inventor)

    1988-01-01

    A miscomparison between a channel's configuration data base and a voted system configuration data base in a redundant channel system having identically operating, frame synchronous channels triggers autoequalization of the channel's historical signal data bases in a hierarchical, chronological manner with that of a correctly operating channel. After equalization, symmetrization of the channel's configuration data base with that of the system permits upgrading of the previously degraded channel to full redundancy. An externally provided equalization command, e.g., manually actuated, can also trigger equalization.

  5. Patients as experts: a collaborative performance support system.

    PubMed Central

    Porter, S. C.

    2001-01-01

    Performance support systems that provide decision support and encourage quality improvement historically focus on physicians as the expert to the exclusion of an active role for patients. This paper outlines an argument for the development of a collaborative expert system in the acute care setting that emphasizes a key role for patients. Patients are not just seekers of information; they remain capable of sharing and integrating their knowledge and expertise actively in an electronically-supported care process. Collaborative use of information technology emerges as a novel variation of consumer informatics. I will define specific domains of expertise for patients and place the proposed collaborative expert system within the framework of Wagner's view of idealized collaborative care for chronic illness. Basic architecture for a patient-inclusive system is proposed with additional detail provided for a patient-level interface targeting pediatric asthma. The benefits of the electronically-supported collaboration include the activation of patients in the information-sharing process, enhanced decision support, a patient-focused needs assessment, and improved communication and partnership between patients and providers. PMID:11825247

  6. User's guide for the thermal analyst's help desk expert system

    NASA Technical Reports Server (NTRS)

    Ormsby, Rachel A.

    1994-01-01

    A guide for users of the Thermal Analyst's Help Desk is provided. Help Desk is an expert system that runs on a DOS based personal computer and operates within the EXSYS expert system shell. Help Desk is an analysis tool designed to provide users having various degrees of experience with the capability to determine first approximations of thermal capacity for spacecraft and instruments. The five analyses supported in Help Desk are: surface area required for a radiating surface, equilibrium temperature of a surface, enclosure temperature and heat loads for a defined position in orbit, enclosure temperature and heat loads over a complete orbit, and selection of appropriate surface properties. The two geometries supported by Help Desk are a single flat plate and a rectangular box enclosure.

  7. Expert systems and their use in nuclear power plants

    SciTech Connect

    Uhrig, R.E. |

    1990-12-31

    In the operation of a nuclear power plant, great quantities of numeric, symbolic, and quantitative information are handled by the reactor operators even during routine operation. The sheer magnitude of the number of process parameters and systems interactions poses difficulties for the operators, particularly during abnormal or emergency situations. Recovery from an upset situation depends upon the facility with which available raw data can be converted into, and assimilated as, meaningful knowledge. In operating a nuclear power plant, people are sometimes affected by fatigue, stress, emotion, and environmental factors that may have varying degrees of influence on their performance. Expert systems provide a method of removing some of the uncertainty from operator decisions by providing expert advice and rapid access to a large information base. 74 refs., 2 tabs.

  8. Developments in REDES: The rocket engine design expert system

    NASA Technical Reports Server (NTRS)

    Davidian, Kenneth O.

    1990-01-01

    The Rocket Engine Design Expert System (REDES) is being developed at the NASA-Lewis to collect, automate, and perpetuate the existing expertise of performing a comprehensive rocket engine analysis and design. Currently, REDES uses the rigorous JANNAF methodology to analyze the performance of the thrust chamber and perform computational studies of liquid rocket engine problems. The following computer codes were included in REDES: a gas properties program named GASP, a nozzle design program named RAO, a regenerative cooling channel performance evaluation code named RTE, and the JANNAF standard liquid rocket engine performance prediction code TDK (including performance evaluation modules ODE, ODK, TDE, TDK, and BLM). Computational analyses are being conducted by REDES to provide solutions to liquid rocket engine thrust chamber problems. REDES is built in the Knowledge Engineering Environment (KEE) expert system shell and runs on a Sun 4/110 computer.

  9. Developments in REDES: The Rocket Engine Design Expert System

    NASA Technical Reports Server (NTRS)

    Davidian, Kenneth O.

    1990-01-01

    The Rocket Engine Design Expert System (REDES) was developed at NASA-Lewis to collect, automate, and perpetuate the existing expertise of performing a comprehensive rocket engine analysis and design. Currently, REDES uses the rigorous JANNAF methodology to analyze the performance of the thrust chamber and perform computational studies of liquid rocket engine problems. The following computer codes were included in REDES: a gas properties program named GASP; a nozzle design program named RAO; a regenerative cooling channel performance evaluation code named RTE; and the JANNAF standard liquid rocket engine performance prediction code TDK (including performance evaluation modules ODE, ODK, TDE, TDK, and BLM). Computational analyses are being conducted by REDES to provide solutions to liquid rocket engine thrust chamber problems. REDES was built in the Knowledge Engineering Environment (KEE) expert system shell and runs on a Sun 4/110 computer.

  10. Java Expert System Shell Version 6.0

    SciTech Connect

    Friedman-Hill, Ernest

    2002-06-18

    Java Expert Shell System - Jess - is a rule engine and scripting environment written entirely in Sun's Java language, Jess was orginially inspired by the CLIPS expert system shell, but has grown int a complete, distinct JAVA-influenced environment of its own. Using Jess, you can build Java applets and applications that have the capacity to "reason" using knowledge you supply in the form of declarative rules. Jess is surprisingly fast, and for some problems is faster than CLIPS, in that many Jess scripts are valid CLIPS scripts and vice-versa. Like CLIPS, Jess uses the Rete algorithm to process rules, a very efficient mechanism for solving the difficult many-to-many matching problem. Jess adds many features to CLIPS, including backwards chaining and the ability to manipulate and directly reason about Java objects. Jess is also a powerful Java scripting environment, from which you can create Java objects and call Java methods without compiling any Java Code.

  11. An expert system for geologic mapping with imaging spectrometers

    NASA Technical Reports Server (NTRS)

    Kruse, F. A.; Seznec, O.; Krotkov, P. M.

    1990-01-01

    Techniques have been developed for the extraction and characterization of absorption features from visible and infrared reflectance spectra and an expert system has been designed, implemented, and successfully tested that allows automated identification of minerals based on their spectral characteristics. A suite of laboratory spectra of common minerals was analyzed and the absorption band characteristics tabulated and used to develop a generalized knowledge base for analysis of the reflectance spectra. A tree hierarchy was designed to emulate the decision process followed by an experienced analyst for analysis of laboratory and field reflectance spectra and aircraft imaging spectrometer spectra. Good results were obtained with the expert system for all three types of spectra, with the critical factor in the analysis being the signal-to-noise ratio of the spectral data.

  12. A CLIPS expert system for clinical flow cytometry data analysis

    NASA Technical Reports Server (NTRS)

    Salzman, G. C.; Duque, R. E.; Braylan, R. C.; Stewart, C. C.

    1990-01-01

    An expert system is being developed using CLIPS to assist clinicians in the analysis of multivariate flow cytometry data from cancer patients. Cluster analysis is used to find subpopulations representing various cell types in multiple datasets each consisting of four to five measurements on each of 5000 cells. CLIPS facts are derived from results of the clustering. CLIPS rules are based on the expertise of Drs. Stewart, Duque, and Braylan. The rules incorporate certainty factors based on case histories.

  13. Hematology Expert System (HES) For Tonsillectomy/Adenoidectomy Patients

    NASA Astrophysics Data System (ADS)

    Pizzi, Nicolino J.; Kapoor, Sandhya; Gerrard, Jon M.

    1989-03-01

    The purpose of this expert system is to assess a predisposition to bleeding in a patient undergoing a tonsillectomy and/or adenoidectomy as may occur with patients who have certain blood conditions such as hemophilia and von Willebrand's disease. This goal is achieved by establishing a correlation between the patients' responses to a medical questionnaire and the relative quantities of blood lost during the operation.

  14. Parallel Inferencing For Rule-Based Expert Systems

    NASA Technical Reports Server (NTRS)

    Schwuttke, Ursula M.; Moldovan, Dan; Kuo, Steve

    1991-01-01

    Improved approach to development of expert-system computer programs increases speed of execution on parallel processors; that is, on multiple coordinated computers operating simultaneously, each on different part of problem. Based on detection and analysis of hidden parallelism in knowledge bases (collections of "if...then..." rules) and exploitation of this parallelism to maximize speed of execution on parallel processors connected to each other in hypercube configuration.

  15. Artificial intelligence, expert systems, computer vision, and natural language processing

    NASA Technical Reports Server (NTRS)

    Gevarter, W. B.

    1984-01-01

    An overview of artificial intelligence (AI), its core ingredients, and its applications is presented. The knowledge representation, logic, problem solving approaches, languages, and computers pertaining to AI are examined, and the state of the art in AI is reviewed. The use of AI in expert systems, computer vision, natural language processing, speech recognition and understanding, speech synthesis, problem solving, and planning is examined. Basic AI topics, including automation, search-oriented problem solving, knowledge representation, and computational logic, are discussed.

  16. Expert system for noise-ridden interferometric data analysis

    NASA Astrophysics Data System (ADS)

    Joo, Wonjong; Cha, Soyoung S.

    1993-12-01

    Automation of interferogram analysis is very important for successful application of all interferometric measurement techniques. In high-speed aerodynamics or experimental mechanics, complex noise-ridden fringe patterns frequently arise due to prevailing adverse environments. In conventional practice, only local information has been heavily utilized to reduce background noise or to correct phase information. Under these circumstances, the currently available techniques, that is, fringe tracking, phase-shifting, Fourier transform, and regression methods, confront difficulties in phase unwrapping and thus need substantial interactive manual operations. The developed rule-based expert system utilizes both global/regional and local information, and makes use of expert knowledge. It can thus provide a potential for more comprehensive automation in noise reduction and phase unwrapping. The developed expert system adopts a hybrid mechanism in a single package, that is, the low-level and high-level processings to produce an optimal solution in fringe analysis. The system can be coupled with any current interferometric reduction techniques, being based on the analysis of isophase contour lines.

  17. C-APACS: a connectionist expert system architecture

    NASA Astrophysics Data System (ADS)

    Chan, Keith C. C.; Ching, John Y.; Wong, Andrew K. C.

    1992-09-01

    In this paper, we present an expert system architecture based on a new artificial neural network. Unlike other connectionist approaches, the proposed network paradigm is able to synthesize explicit production rules from the processing elements and the weighted connections of a trained network. The generated rules can be incorporated into an expert system to perform classification tasks such as engineering troubleshooting. The design of the neural network is based on the concepts of probabilistic inference. The network can identify the relevant attributes for classification using a statistical technique called residual analysis. Using the information theoretic weight of evidence measure, the weighted connections are established between the processing elements representing the important attribute values and classes. The proposed network is non-iterative and is therefore very efficient computationally. Since the topology of the network is deterministic, the heuristic functions of each element can be precisely understood and the internal associations directly analyzed to synthesize explicit and intuitive classification rules. This network has been shown previously to outperform the back propagation networks and ID3 in terms of computational efficiency and classification accuracy in certain types of supervised learning applications. Using a typical fault diagnosis task, we show in this paper that the proposed neural network can be used effectively to acquire knowledge for rule-based expert systems. Compared to other AI-based knowledge acquisition approaches using AQ and CN2 algorithms, our proposed approach has the fastest training time while producing the most effective classification rules.

  18. Redundancy approaches in spacecraft computers

    NASA Astrophysics Data System (ADS)

    Schonfeld, Chaim

    Twelve redundancy techniques for spacecraft computers are analyzed. The redundancy schemes include: a single unit; two active units; triple modular redundancy; NMR; a single unit with one and two spares; two units with one, two, and three spares; triple units with one and two spares; and a single unit with a spare per module; the basic properties of these schemes are described. The reliability of each scheme is evaluated as a function of the reliability of a single unit. The redundancy schemes are compared in terms of reliability, the number of failures the system can tolerate, coverage, recovery time, and mean time between failure improvement. The error detection and recovery systems and the random access memory redundancy of the schemes are examined. The data reveal that the single unit with a spare per module is the most effective redundancy approach; a description of the scheme is provided.

  19. Proceedings of the ROBEXS '86: The second annual workshop on robotics and expert systems

    SciTech Connect

    Not Available

    1986-01-01

    This book presents papers given at a workshop on robots and expert systems. Topics include the following: Natural Language and Artificial Intelligence; Software engineering and expert systems; robots in space; artificial intelligence and the human interface; and Fuzzy Logic Systems.

  20. Real time AI expert system for robotic applications

    NASA Technical Reports Server (NTRS)

    Follin, John F.

    1987-01-01

    A computer controlled multi-robot process cell to demonstrate advanced technologies for the demilitarization of obsolete chemical munitions was developed. The methods through which the vision system and other sensory inputs were used by the artificial intelligence to provide the information required to direct the robots to complete the desired task are discussed. The mechanisms that the expert system uses to solve problems (goals), the different rule data base, and the methods for adapting this control system to any device that can be controlled or programmed through a high level computer interface are discussed.