Sample records for adaptive hypermedia systems

  1. Adaptive Hypermedia Educational System Based on XML Technologies.

    ERIC Educational Resources Information Center

    Baek, Yeongtae; Wang, Changjong; Lee, Sehoon

    This paper proposes an adaptive hypermedia educational system using XML technologies, such as XML, XSL, XSLT, and XLink. Adaptive systems are capable of altering the presentation of the content of the hypermedia on the basis of a dynamic understanding of the individual user. The user profile can be collected in a user model, while the knowledge…

  2. Adaptive Learning Resources Sequencing in Educational Hypermedia Systems

    ERIC Educational Resources Information Center

    Karampiperis, Pythagoras; Sampson, Demetrios

    2005-01-01

    Adaptive learning resources selection and sequencing is recognized as among the most interesting research questions in adaptive educational hypermedia systems (AEHS). In order to adaptively select and sequence learning resources in AEHS, the definition of adaptation rules contained in the Adaptation Model, is required. Although, some efforts have…

  3. A Model for an Adaptive e-Learning Hypermedia System

    ERIC Educational Resources Information Center

    Mahnane, Lamia; Tayeb, Laskri Mohamed; Trigano, Philippe

    2013-01-01

    Recent years have shown increasing awareness for the importance of adaptivity in e-learning. Since the learning style of each learner is different. Adaptive e-learning hypermedia system (AEHS) must fit different learner's needs. A number of AEHS have been developed to support learning styles as a source for adaptation. However, these systems…

  4. The New Trends in Adaptive Educational Hypermedia Systems

    ERIC Educational Resources Information Center

    Somyürek, Sibel

    2015-01-01

    This paper aims to give a general review of existing literature on adaptive educational hypermedia systems and to reveal technological trends and approaches within these studies. Fifty-six studies conducted between 2002 and 2012 were examined, to identify prominent themes and approaches. According to the content analysis, the new technological…

  5. Combining Adaptive Hypermedia with Project and Case-Based Learning

    ERIC Educational Resources Information Center

    Papanikolaou, Kyparisia; Grigoriadou, Maria

    2009-01-01

    In this article we investigate the design of educational hypermedia based on constructivist learning theories. According to the principles of project and case-based learning we present the design rational of an Adaptive Educational Hypermedia system prototype named MyProject; learners working with MyProject undertake a project and the system…

  6. The Optimization by Using the Learning Styles in the Adaptive Hypermedia Applications

    ERIC Educational Resources Information Center

    Hamza, Lamia; Tlili, Guiassa Yamina

    2018-01-01

    This article addresses the learning style as a criterion for optimization of adaptive content in hypermedia applications. First, the authors present the different optimization approaches proposed in the area of adaptive hypermedia systems whose goal is to define the optimization problem in this type of system. Then, they present the architecture…

  7. Patterns in Authoring of Adaptive Educational Hypermedia: A Taxonomy of Learning Styles

    ERIC Educational Resources Information Center

    Brown, Elizabeth; Cristea, Alexandra; Stewart, Craig; Brailsford, Tim

    2005-01-01

    This paper describes the use of adaptation patterns in the task of formulating standards for adaptive educational hypermedia (AEH) systems that is currently under investigation by the EU ADAPT project. Within this project, design dimensions for high granularity patterns have been established. In this paper we focus on detailing lower granularity…

  8. Hypertext and hypermedia systems in information retrieval

    NASA Technical Reports Server (NTRS)

    Kaye, K. M.; Kuhn, A. D.

    1992-01-01

    This paper opens with a brief history of hypertext and hypermedia in the context of information management during the 'information age.' Relevant terms are defined and the approach of the paper is explained. Linear and hypermedia information access methods are contrasted. A discussion of hyperprogramming in the handling of complex scientific and technical information follows. A selection of innovative hypermedia systems is discussed. An analysis of the Clinical Practice Library of Medicine NASA STI Program hypermedia application is presented. The paper concludes with a discussion of the NASA STI Program's future hypermedia project plans.

  9. A Hypermedia Information System for Aviation.

    ERIC Educational Resources Information Center

    Hartzell, Karin M.

    The Hypermedia Information System (HIS) is being developed under the auspices of the Federal Aviation Administration (FAA) Office of Aviation Medicine's (AAM) Human Factors in Aviation Maintenance (HFAM) research program. The goal of the hypermedia project is to create new tools and methods for aviation-related information storage and retrieval.…

  10. What Can the Semantic Web Do for Adaptive Educational Hypermedia?

    ERIC Educational Resources Information Center

    Cristea, Alexandra I.

    2004-01-01

    Semantic Web and Adaptive Hypermedia come from different backgrounds, but it turns out that actually, they can benefit from each other, and that their confluence can lead to synergistic effects. This encounter can influence several fields, among which an important one is Education. This paper presents an analysis of this encounter, first from a…

  11. An Approach for Automatic Generation of Adaptive Hypermedia in Education with Multilingual Knowledge Discovery Techniques

    ERIC Educational Resources Information Center

    Alfonseca, Enrique; Rodriguez, Pilar; Perez, Diana

    2007-01-01

    This work describes a framework that combines techniques from Adaptive Hypermedia and Natural Language processing in order to create, in a fully automated way, on-line information systems from linear texts in electronic format, such as textbooks. The process is divided into two steps: an "off-line" processing step, which analyses the source text,…

  12. Semantic Description of Educational Adaptive Hypermedia Based on a Conceptual Model

    ERIC Educational Resources Information Center

    Papasalouros, Andreas; Retalis, Symeon; Papaspyrou, Nikolaos

    2004-01-01

    The role of conceptual modeling in Educational Adaptive Hypermedia Applications (EAHA) is especially important. A conceptual model of an educational application depicts the instructional solution that is implemented, containing information about concepts that must be ac-quired by learners, tasks in which learners must be involved and resources…

  13. Issues in Designing a Hypermedia Document System: The Intermedia Case Study.

    ERIC Educational Resources Information Center

    Yankelovich, Nicole; And Others

    1986-01-01

    Intermedia, a hypermedia system developed at Brown University's Institute for Research (Rhode Island) in Information and Scholarship, is first described, and then used as a case study to explore a number of key issues that software designers must consider in the development of hypermedia document systems. A hypermedia document system is defined as…

  14. Does Adaptive Scaffolding Facilitate Students' Ability to Regulate their Learning with Hypermedia?

    ERIC Educational Resources Information Center

    Azevedo, Roger; Cromley, Jennifer G.; Seibert, Diane

    2004-01-01

    Is adaptive scaffolding effective in facilitating students' ability to regulate their learning of complex science topics with hypermedia? We examined the role of different scaffolding instructional interventions in facilitating students' shift to more sophisticated mental models as indicated by both performance and process data. Undergraduate…

  15. Hypermedia (Multimedia).

    ERIC Educational Resources Information Center

    Byrom, Elizabeth

    1990-01-01

    Hypermedia allows students to follow associative links among elements of nonsequential information, by combining information from multiple sources into one microcomputer-controlled system. Hypermedia products help teachers create lessons integrating text, motion film, color graphics, speech, and music, by linking such electronic devices as…

  16. Parasitology tutoring system: a hypermedia computer-based application.

    PubMed

    Theodoropoulos, G; Loumos, V

    1994-02-14

    The teaching of parasitology is a basic course in all life sciences curricula, and up to now no computer-assisted tutoring system has been developed for this purpose. By using Knowledge Pro, an object-oriented software development tool, a hypermedia tutoring system for teaching parasitology to college students was developed. Generally, a tutoring system contains a domain expert, a student model, a pedagogical expert and the user interface. In this project, particular emphasis was given to the user interface design and the expert knowledge representation. The system allows access to the educational material through hypermedia and indexing at the pace of the student. The hypermedia access is facilitated through key words defined as hypertext and objects in pictures defined as hyper-areas. The indexing access is based on a list of parameters that refers to various characteristics of the parasites, e.g. taxonomy, host, organ, etc. In addition, this indexing access can be used for testing the student's level of understanding. The advantages of this system are its user-friendliness, graphical interface and ability to incorporate new educational material in the area of parasitology.

  17. A model for addressing navigation limitations and metacognitive constraints in hypermedia training systems

    NASA Technical Reports Server (NTRS)

    Freedman, Glenn B.

    1990-01-01

    A model for addressing navigation limitations and metacognitive constraints in hypermedia training systems is presented in the form of the viewgraphs. The following subject areas are covered: samples of software and people problems; system design; and hypermedia training system.

  18. Considerations regarding the deployment of hypermedia at JSC

    NASA Technical Reports Server (NTRS)

    Kacmar, Charles J.

    1993-01-01

    Electronic documents and systems are becoming the primary means of managing information for ground and space operations at NASA. These documents will utilize hypertext and hypermedia technologies to aid users in structuring and accessing information. Documents will be composed of static and dynamic data consisting of user-defined annotations and hypermedia links. The report consists of three major sections. First, it provides an overview of hypermedia and surveys the use of hypermedia throughout JSC. Second, it briefly describes a prototypical hypermedia system that was developed in conjunction with this work. This system was constructed to demonstrate various hypermedia features and to serve as a platform for supporting the electronic documentation needs for the MIDAS system developed by the Intelligent Systems Branch of the Automation and Robotics Division (Pac92). Third, it discusses emerging hypermedia technologies which have either been untapped by vendors or present significant challenges to the Agency.

  19. Streamlining ICAT development through off-the shelf hypermedia systems

    NASA Technical Reports Server (NTRS)

    Orey, Michael; Trent, Ann; Young, James; Sanders, Michael

    1993-01-01

    This project examined the efficacy of building intelligent computer assisted training using an off-the-shelf hypermedia package. In addition, we compared this package to an architecture that had been developed in a previous contract which was based in the C programming language. One person developed a tutor in LinkWay (an off-the-shelf hypermedia system) and another developed the same tutor using the ALM C-based architecture. Development times, ease of use, learner preferences, learner options, and learning effectiveness were compared. In all cases, the off-the-shelf package was shown to be superior to the C-based system.

  20. Hypermedia Tutoring System: Towards an Architecture Dedicated to the WEB Specification.

    ERIC Educational Resources Information Center

    Beltran, T.; Peninou, A.

    The first stage of the HyTuS (Hypermedia Tutoring System) project, developed by the Alliance Francaise (a training institute supplying French courses for foreigners in France and abroad), and professional partners, is presented. The aim of the project is to provide a hypermedia CD-ROM-based environment for learning French according to the Alliance…

  1. Analyzing Hypermedia and Internet Communication Models in Educational Applications

    ERIC Educational Resources Information Center

    Saxena, Anshu; Kothari, D. P.; Jain, Sudhir K.; Khurana, Amulya

    2004-01-01

    Hypermedia has long been considered to have great potential to support educational tasks and applications. Many success stories of hypermedia support in education have been reported. Much of this work has been done in the context of traditional closed hypermedia systems rather than more contemporary open hypermedia systems. Developing hypermedia…

  2. What Affect Student Cognitive Style in the Development of Hypermedia Learning System?

    ERIC Educational Resources Information Center

    Lee, Catherine Hui Min; Cheng, Yuk Wing; Rai, Shri; Depickere, Arnold

    2005-01-01

    Recent developments in learning technology such as hypermedia is becoming widespread and offer significant contribution to improve the delivery of learning and teaching materials. A key factor in the development of hypermedia learning system is cognitive style (CS) as it relates to users' information processing habits, representing individual…

  3. Learner Control in Hypermedia Environments

    ERIC Educational Resources Information Center

    Scheiter, Katharina; Gerjets, Peter

    2007-01-01

    Contrary to system-controlled multimedia learning environments, hypermedia systems are characterized by a high level of interactivity. This interactivity is referred to as learner control in the respective literature. For several reasons this learner control is seen as a major advantage of hypermedia for learning and instruction. For instance,…

  4. Hypermedia Competencies

    ERIC Educational Resources Information Center

    Chen, Der-Thanq; Liang, Rose; Wang, Yu-mei

    2014-01-01

    Hypermedia has received increasing attention since the 1980s and this has been followed by an increasing interest in utilizing hypermedia in the domain of education. Many successful projects have been reported. In most cases, students used hypermedia designed environments to search for information and to navigate from one place to another. In this…

  5. Adaptive Systems in Education: A Review and Conceptual Unification

    ERIC Educational Resources Information Center

    Wilson, Chunyu; Scott, Bernard

    2017-01-01

    Purpose: The purpose of this paper is to review the use of adaptive systems in education. It is intended to be a useful introduction for the non-specialist reader. Design/methodology/approach: A distinction is made between intelligent tutoring systems (ITSs) and adaptive hypermedia systems (AHSs). The two kinds of system are defined, compared and…

  6. A Hypermedia Computer-Aided Parasitology Tutoring System.

    ERIC Educational Resources Information Center

    Theodoropoulos, Georgios; Loumos, Vassili

    A hypermedia tutoring system for teaching parasitology to college students was developed using an object oriented software development tool, Knowledge Pro. The program was designed to meet four objectives: knowledge incorporation, tutoring, indexing of key words for Boolean search, and random generation of quiz questions with instant scoring. The…

  7. Collaborative Hypermedia in a Classroom Setting.

    ERIC Educational Resources Information Center

    Rada, Roy; And Others

    1994-01-01

    Examines the role of a collaborative hypermedia system, called Multiple Users Creating Hypermedia (MUCH), in aiding students in the authoring process. Students were instructed to use the annotation facility of the system to comment on others' work. It was found that those who made comments were more likely to improve their own performance than…

  8. PERSO: Towards an Adaptive e-Learning System

    ERIC Educational Resources Information Center

    Chorfi, Henda; Jemni, Mohamed

    2004-01-01

    In today's information technology society, members are increasingly required to be up to date on new technologies, particularly for computers, regardless of their background social situation. In this context, our aim is to design and develop an adaptive hypermedia e-learning system, called PERSO (PERSOnalizing e-learning system), where learners…

  9. Regional information guidance system based on hypermedia concept

    NASA Astrophysics Data System (ADS)

    Matoba, Hiroshi; Hara, Yoshinori; Kasahara, Yutako

    1990-08-01

    A regional information guidance system has been developed on an image workstation. Two main features of this system are hypermedia data structure and friendly visual interface realized by the full-color frame memory system. As the hypermedia data structure manages regional information such as maps, pictures and explanations of points of interest, users can retrieve those information one by one, next to next according to their interest change. For example, users can retrieve explanation of a picture through the link between pictures and text explanations. Users can also traverse from one document to another by using keywords as cross reference indices. The second feature is to utilize a full-color, high resolution and wide space frame memory for visual interface design. This frame memory system enables real-time operation of image data and natural scene representation. The system also provides half tone representing function which enables fade-in/out presentations. This fade-in/out functions used in displaying and erasing menu and image data, makes visual interface soft for human eyes. The system we have developed is a typical example of multimedia applications. We expect the image workstation will play an important role as a platform for multimedia applications.

  10. Applications of hypermedia systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lennon, J.; Maurer, H.

    1995-05-01

    In this paper, we consider several new aspects of modern hypermedia systems. The applications discussed include: (1) General Information and Communication Systems: Distributed information systems for businesses, schools and universities, museums, libraries, health systems, etc. (2) Electronic orientation and information displays: Electronic guided tours, public information kiosks, and publicity dissemination with archive facilities. (3) Lecturing: A system going beyond the traditional to empower both teachers and learners. (4) Libraries: A further step towards fully electronic library systems. (5) Directories of all kinds: Staff, telephone, and all sorts of generic directories. (6) Administration: A fully integrated system such as the onemore » proposed will mean efficient data processing and valuable statistical data. (7) Research: Material can now be accessed from databases all around the world. The effects of networking and computer-supported collaborative work are discussed, and examples of new scientific visualization programs are quoted. The paper concludes with a section entitled {open_quotes}Future Directions{close_quotes}.« less

  11. Developing Adaptive Systems at Early Stages of Children's Foreign Language Development

    ERIC Educational Resources Information Center

    Espada, Ana Belen Cumbreno; Garcia, Mercedes Rico; Fuentes, Alejandro Curado; Gomez, Eva Ma Dominguez

    2006-01-01

    This paper describes the integration of hypermedia adaptive systems for foreign language learners at an early age. Our research project is concerned with exploring the relationship between language learning and information technology according to six different phases: a preliminary study of the plausible adaptive system; the development of lessons…

  12. Instructional Design and the Authoring of Multimedia and Hypermedia Systems: Does a Marriage Make Sense?

    ERIC Educational Resources Information Center

    Gros, Begona; And Others

    1997-01-01

    Examines the relationship between instructional design (ID) and courseware development, especially for multimedia and hypermedia systems. Discusses ID models; external and internal reasons for the neglect of models; characteristics of models suitable for multimedia and hypermedia development; and models integrating those characteristics: Guided…

  13. The Application of Large-Scale Hypermedia Information Systems to Training.

    ERIC Educational Resources Information Center

    Crowder, Richard; And Others

    1995-01-01

    Discusses the use of hypermedia in electronic information systems that support maintenance operations in large-scale industrial plants. Findings show that after establishing an information system, the same resource base can be used to train personnel how to use the computer system and how to perform operational and maintenance tasks. (Author/JMV)

  14. Teaching English Engineering Terminology in a Hypermedia Environment.

    ERIC Educational Resources Information Center

    Stamison-Atmatzidi, M.; And Others

    1995-01-01

    Discusses a hypermedia prototype system constituting a hypermedia dictionary environment and a database of field-specific reading passages with related exercises, for utilization in the teaching of English engineering terminology in foreign language environments. (eight references) (CK)

  15. Process and information integration via hypermedia

    NASA Technical Reports Server (NTRS)

    Hammen, David G.; Labasse, Daniel L.; Myers, Robert M.

    1990-01-01

    Success stories for advanced automation prototypes abound in the literature but the deployments of practical large systems are few in number. There are several factors that militate against the maturation of such prototypes into products. Here, the integration of advanced automation software into large systems is discussed. Advanced automation systems tend to be specific applications that need to be integrated and aggregated into larger systems. Systems integration can be achieved by providing expert user-developers with verified tools to efficiently create small systems that interface to large systems through standard interfaces. The use of hypermedia as such a tool in the context of the ground control centers that support Shuttle and space station operations is explored. Hypermedia can be an integrating platform for data, conventional software, and advanced automation software, enabling data integration through the display of diverse types of information and through the creation of associative links between chunks of information. Further, hypermedia enables process integration through graphical invoking of system functions. Through analysis and examples, researchers illustrate how diverse information and processing paradigms can be integrated into a single software platform.

  16. Hypermedia and intelligent tutoring applications in a mission operations environment

    NASA Technical Reports Server (NTRS)

    Ames, Troy; Baker, Clifford

    1990-01-01

    Hypermedia, hypertext and Intelligent Tutoring System (ITS) applications to support all phases of mission operations are investigated. The application of hypermedia and ITS technology to improve system performance and safety in supervisory control is described - with an emphasis on modeling operator's intentions in the form of goals, plans, tasks, and actions. Review of hypermedia and ITS technology is presented as may be applied to the tutoring of command and control languages. Hypertext based ITS is developed to train flight operation teams and System Test and Operation Language (STOL). Specific hypermedia and ITS application areas are highlighted, including: computer aided instruction of flight operation teams (STOL ITS) and control center software development tools (CHIMES and STOL Certification Tool).

  17. Expressing Adaptation Strategies Using Adaptation Patterns

    ERIC Educational Resources Information Center

    Zemirline, N.; Bourda, Y.; Reynaud, C.

    2012-01-01

    Today, there is a real challenge to enable personalized access to information. Several systems have been proposed to address this challenge including Adaptive Hypermedia Systems (AHSs). However, the specification of adaptation strategies remains a difficult task for creators of such systems. In this paper, we consider the problem of the definition…

  18. Hypermedia Design as Learner Scaffolding

    ERIC Educational Resources Information Center

    Shapiro, Amy M.

    2008-01-01

    A number of available resources offer guidance about hypermedia design strategies, many of which rely on principles of user-centered design. Many recent efforts, however, have focused more on developing "learner-centered" hypermedia. Learner-centered hypermedia is designed to help learners achieve their educational goals, rather than offer mere…

  19. A hypermedia reference system to the Forest Ecosystem Management Assessment team report and some related publications.

    Treesearch

    K.M. Reynolds; H.M. Rauscher; C.V. Worth

    1995-01-01

    The hypermedia system, ForestEM, was developed in HyperWriter for use in Microsoft Windows. ForestEM version 1.0 includes text and figures from the FEMAT report and the Record of Decision and Standards and Guidelines. Hypermedia introduces two fundamental changes to knowledge management. The first is the capability to interactively store and retrieve large amounts of...

  20. Automation and hypermedia technology applications

    NASA Technical Reports Server (NTRS)

    Jupin, Joseph H.; Ng, Edward W.; James, Mark L.

    1993-01-01

    This paper represents a progress report on HyLite (Hypermedia Library technology): a research and development activity to produce a versatile system as part of NASA's technology thrusts in automation, information sciences, and communications. HyLite can be used as a system or tool to facilitate the creation and maintenance of large distributed electronic libraries. The contents of such a library may be software components, hardware parts or designs, scientific data sets or databases, configuration management information, etc. Proliferation of computer use has made the diversity and quantity of information too large for any single user to sort, process, and utilize effectively. In response to this information deluge, we have created HyLite to enable the user to process relevant information into a more efficient organization for presentation, retrieval, and readability. To accomplish this end, we have incorporated various AI techniques into the HyLite hypermedia engine to facilitate parameters and properties of the system. The proposed techniques include intelligent searching tools for the libraries, intelligent retrievals, and navigational assistance based on user histories. HyLite itself is based on an earlier project, the Encyclopedia of Software Components (ESC) which used hypermedia to facilitate and encourage software reuse.

  1. Teaching and Learning with Flexible Hypermedia Learning Environments.

    ERIC Educational Resources Information Center

    Wedekind, Joachim; Lechner, Martin; Tergan, Sigmar-Olaf

    This paper presents an approach for developing flexible Hypermedia Learning Environments (HMLE) and applies this theoretical framework to the creation of a layered model of a hypermedia system, called HyperDisc, developed at the German Institute for Research on Distance Education. The first section introduces HMLE and suggests that existing…

  2. Effects of Reflection Prompts when Learning with Hypermedia

    ERIC Educational Resources Information Center

    Bannert, Maria

    2006-01-01

    In this study the assumption was tested experimentally, whether prompting for reflection will enhance hypermedia learning and transfer. Students of the experimental group were prompted at each navigation step in a hypermedia system to say the reasons why they chose this specific information node out loud whereas the students of the control group…

  3. A Hypermedia Approach to the Design of an Intelligent Tutoring System

    DTIC Science & Technology

    1991-09-01

    23 3. Artist and Exploration Method ........................................... 24 4. Research method...LIMITATIONS AND FUTURE RESEARCH ............................................................... 76 v B. A CASE FOR HYPERMEDIA LEARNING ENVIRONMENTS...119 vi I. INTRODUCTION Most of the prior research in the field of intelligent tutoring systems (ITS) has focused on

  4. The Design and the Formative Evaluation of an Adaptive Educational System Based on Cognitive Styles

    ERIC Educational Resources Information Center

    Triantafillou, Evangelos; Pomportsis, Andreas; Demetriadis, Stavros

    2003-01-01

    Adaptive Hypermedia Systems (AHS) can be developed to accommodate a variety of individual differences, including learning style and cognitive style. The current research is an attempt to examine some of the critical variables, which may be important in the design of an Adaptive Educational System (AES) based on student's cognitive style. Moreover,…

  5. Adaptivity in ProPer: An Adaptive SCORM Compliant LMS

    ERIC Educational Resources Information Center

    Kazanidis, Ioannis; Satratzemi, Maya

    2009-01-01

    Adaptive Educational Hypermedia Systems provide personalized educational content to learners. However most of them do not support the functionality of Learning Management Systems (LMS) and the reusability of their courses is hard work. On the other hand some LMS support SCORM specifications but do not provide adaptive features. This article…

  6. User Modeling in Adaptive Hypermedia Educational Systems

    ERIC Educational Resources Information Center

    Martins, Antonio Constantino; Faria, Luiz; Vaz de Carvalho, Carlos; Carrapatoso, Eurico

    2008-01-01

    This document is a survey in the research area of User Modeling (UM) for the specific field of Adaptive Learning. The aims of this document are: To define what it is a User Model; To present existing and well known User Models; To analyze the existent standards related with UM; To compare existing systems. In the scientific area of User Modeling…

  7. An Experimental Comparison of the Flexibility in the Use of Thinking Styles in Traditional and Hypermedia Learning Environments

    ERIC Educational Resources Information Center

    Fan, Weiqiao

    2012-01-01

    The objective of the instructional experiment was to examine if the use of thinking styles is flexible in traditional and hypermedia learning environments, and if a hypermedia learning environment possesses obvious advantages than a traditional environment in adapting to students with different thinking styles. The participant university students…

  8. Conceptual and Methodological Shortcomings in Hypertext/Hypermedia Design and Research.

    ERIC Educational Resources Information Center

    Tergan, Sigmar-Olaf

    1997-01-01

    Some studies of hypertext/hypermedia systems have concluded that there is little evidence supporting its educational efficacy. After examining conceptual and methodological shortcomings of research, this article suggests that the educational potential of hypertext/hypermedia has been underestimated and argues that overcoming these shortcomings…

  9. Some Conditions for Cost Efficiency in Hypermedia.

    ERIC Educational Resources Information Center

    Westland, J. Christopher

    1998-01-01

    Models administrative and operating costs surrounding a hypermedia database and identifies seven conditions for the cost justification of hypermedia. Concludes that cost considerations aside, hypermedia offers significant data retrieval benefits in accessing text, video, still pictures, and sound, and provides substantially better human…

  10. Modeling Adaptive Educational Methods with IMS Learning Design

    ERIC Educational Resources Information Center

    Specht, Marcus; Burgos, Daniel

    2007-01-01

    The paper describes a classification system for adaptive methods developed in the area of adaptive educational hypermedia based on four dimensions: What components of the educational system are adapted? To what features of the user and the current context does the system adapt? Why does the system adapt? How does the system get the necessary…

  11. Learning Strategies and Hypermedia Instruction.

    ERIC Educational Resources Information Center

    Hartley, Kendall

    2001-01-01

    Investigated the potential of incorporating learning strategy instruction into hypermedia learning materials in a high school computer class. Discusses results of a six-week intervention where the experimental group participated in learning strategy training in conjunction with hypermedia computer networking lessons and reports results of pre- and…

  12. GALE: a generic open source extensible adaptation engine

    NASA Astrophysics Data System (ADS)

    De Bra, Paul; Knutov, Evgeny; Smits, David; Stash, Natalia; Ramos, Vinicius F. C.

    2013-06-01

    This paper motivates and describes GALE, the Generic Adaptation Language and Engine that came out of the GRAPPLE EU FP7 project. The main focus of the paper is the extensible nature of GALE. The purpose of this description is to illustrate how a single core adaptation engine can be used for different types of adaptation, applied to different types of information items and documents. We illustrate the adaptive functionality on some examples of hypermedia documents. In April 2012, David Smits defended the world's first adaptive PhD thesis on this topic. The thesis, available for download and direct adaptive access at http://gale.win.tue.nl/thesis, shows that a single source of information can serve different audiences and at the same time also allows more freedom of navigation than is possible in any paper or static hypermedia document. The same can be done for course texts, hyperfiction, encyclopedia, museum, or other cultural heritage websites, etc. We explain how to add functionality to GALE if desired, to adapt the system's behavior to whatever the application requires. This stresses our main objective: to provide a technological base for adaptive (hypermedia) system researchers on which they can build extensions for the specific research they have in mind.

  13. From knowledge presentation to knowledge representation to knowledge construction: Future directions for hypermedia

    NASA Technical Reports Server (NTRS)

    Palumbo, David B.

    1990-01-01

    Relationships between human memory systems and hypermedia systems are discussed with particular emphasis on the underlying importance of associational memory. The distinctions between knowledge presentation, knowledge representation, and knowledge constructions are addressed. Issues involved in actually developing individualizable hypermedia based knowledge construction tools are presented.

  14. The Design and Assessment of a Hypermedia Course on Semiconductor Manufacturing.

    ERIC Educational Resources Information Center

    Schank, Patrick K.; Rowe, Lawrence A.

    1993-01-01

    Describes the design and evaluation of a multimedia course on integrated circuit manufacturing that was developed at the University of California at Berkeley using IC-HIP (Integrated Circuit-Hypermedia in PICASSO), a hypermedia-based instructional system. Learning effects based on prior knowledge, methods of navigation, and other factors are…

  15. Assessment of student learning with hypermedia tools in first-year college chemistry

    NASA Astrophysics Data System (ADS)

    Skov, Neil Martin

    Learning chemistry is difficult for some students. In response to this difficulty, many educators argue that hypermedia technology can promote learning of abstract chemistry concepts. This research assesses learning outcomes and use patterns exhibited by first-year college general chemistry students using an instructional hypermedia system called Seeing Through Chemistry (STC) as part of their first course. STC was designed to help students with inadequate preparation for college chemistry. The assessment answers two questions: (a) do students learn from instructional hypermedia, and (b) what kind of students benefit from this medium? This non-experimental, quantitative research involved 82 student volunteers in their first college chemistry course. Data include SAT scores, high school science and mathematics grades, career orientation, chemistry placement score, motivation, laboratory and lecture section enrollment, and chemistry course grade. The investigation requires two specialized assessment tools: a measure of conceptual understanding of acids and bases, and a measure of cognitive engagement with hypermedia. Data analysis methods include two causal path models to examine hypermedia use and learning outcomes: one showing STC's effect on overall chemistry course performance, and the other demonstrating the effect of a single STC module on students' conceptual knowledge of acids and bases. Though there is no significant effect on course grade, the second analysis shows statistically significant learning from students' work with instructional hypermedia. Both causal models demonstrate that students with poorer preparation for college chemistry used STC more than students with better preparation, which matches the designers' intent. Some better prepared students were relatively more motivated to use the hypermedia system. Other findings show positive effects of high school science and college laboratory coursework on concept learning. This research informs the

  16. An Exploration and Analysis of the Relationships among Object Oriented Programming, Hypermedia, and Hypertalk.

    ERIC Educational Resources Information Center

    Milet, Lynn K.; Harvey, Francis A.

    Hypermedia and object oriented programming systems (OOPs) represent examples of "open" computer environments that allow the user access to parts of the code or operating system. Both systems share fundamental intellectual concepts (objects, messages, methods, classes, and inheritance), so that an understanding of hypermedia can help in…

  17. A Hypermedia Model for Teaching Technology.

    ERIC Educational Resources Information Center

    Savage, Ernest N.

    Ohio's Model Industrial Technology Systems (MITS) project was initiated in 1987 to achieve the following: identify good activities in the areas of physical, communication, and bio-related technology; standardize the activities' format; and provide a coding system for their eventual use in a hypermedia system. To date, 220 activities have been…

  18. Hypermedia Concepts and Research: An Overview.

    ERIC Educational Resources Information Center

    Burton, John K.; And Others

    1995-01-01

    Provides an overview of hypermedia, including a history of hypertext and multimedia, and discusses how they have been combined into the term hypermedia; a cognitive overview; dual coding and cue summation; and theories related to learners, including field dependence-independence, memory, and metacognition. Contains 156 references. (LRW)

  19. A knowledge base browser using hypermedia

    NASA Technical Reports Server (NTRS)

    Pocklington, Tony; Wang, Lui

    1990-01-01

    A hypermedia system is being developed to browse CLIPS (C Language Integrated Production System) knowledge bases. This system will be used to help train flight controllers for the Mission Control Center. Browsing this knowledge base will be accomplished either by having navigating through the various collection nodes that have already been defined, or through the query languages.

  20. The Effectiveness of Hypermedia Instructional Modules for Radiology Residents.

    ERIC Educational Resources Information Center

    Shaw, Steven G.; And Others

    1995-01-01

    Details the development and field testing of hypermedia training materials for teaching radiology residents at the Montreal General Hospital (Canada). Compares results of randomly teaching 24 residents with either hypermedia or traditional classroom methods. Results indicate that residents who learned with hypermedia generally performed as well as…

  1. HOED: Hypermedia Online Educational Database.

    ERIC Educational Resources Information Center

    Duval, E.; Olivie, H.

    This paper presents HOED, a distributed hypermedia client-server system for educational resources. The aim of HOED is to provide a library facility for hyperdocuments that is accessible via the world wide web. Its main application domain is education. The HOED database not only holds the educational resources themselves, but also data describing…

  2. SEPEC conference proceedings: Hypermedia and Information Reconstruction. Aerospace applications and research directions. Addendum

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The papers presented at the conference on hypermedia and information reconstruction are compiled. The following subject areas are covered: hypertext, typographic man, and the notion of literacy; a knowledge base browser using hypermedia; Ai GERM - a logic programming front end for GERM; and HEAVENS system for software artifacts.

  3. Instructional Applications of Hypermedia: Functional Features, Limitations, and Research Issues.

    ERIC Educational Resources Information Center

    Park, Ok-choon

    1992-01-01

    Defines hypermedia and describes the structure and functional requirements of a hypermedia program. Potentials of hypermedia for instructional delivery, idea generation and organization, file storage and organization, and development of computer-based instruction materials are discussed. Several research issues related to instructional…

  4. Computer-assisted knowledge acquisition for hypermedia systems

    NASA Technical Reports Server (NTRS)

    Steuck, Kurt

    1990-01-01

    The usage of procedural and declarative knowledge to set up the structure or 'web' of a hypermedia environment is described. An automated knowledge acquisition tool was developed that helps a knowledge engineer elicit and represent an expert's knowledge involved in performing procedural tasks. The tool represents both procedural and prerequisite, declarative knowledge that supports each activity performed by the expert. This knowledge is output and subsequently read by a hypertext scripting language to generate the link between blank, but labeled cards. Each step of the expert's activity and each piece of supporting declarative knowledge is set up as an empty node. An instructional developer can then enter detailed instructional material concerning each step and declarative knowledge into these empty nodes. Other research is also described that facilitates the translation of knowledge from one form into a form more readily useable by computerized systems.

  5. Misleading Theoretical Assumptions in Hypertext/Hypermedia Research.

    ERIC Educational Resources Information Center

    Tergan, Sigmar-Olaf

    1997-01-01

    Reviews basic theoretical assumptions of research on learning with hypertext/hypermedia. Focuses on whether the results of research on hypertext/hypermedia-based learning support these assumptions. Results of empirical studies and theoretical analysis reveal that many research approaches have been misled by inappropriate theoretical assumptions on…

  6. Semiotic Criteria for Evaluating Instructional HyperMedia.

    ERIC Educational Resources Information Center

    Tucker, Susan A.; Dempsey, John V.

    This report describes hypermedia as a non-linear interlinked representation of textual, graphic, visual and audio material, that enables students to connect large bodies of information while developing analytical skills necessary to think critically about this information. It is noted that the use of microcomputers for hypermedia instruction…

  7. Thinking Style, Browsing Primes and Hypermedia Navigation

    ERIC Educational Resources Information Center

    Fiorina, Lorenzo; Antonietti, Alessandro; Colombo, Barbara; Bartolomeo, Annella

    2007-01-01

    There is a common assumption that hypermedia navigation is influenced by a learner's style of thinking, so people who are inclined to apply sequential and analytical strategies (left-thinkers) are thought to browse hypermedia in a linear way, whereas those who prefer holistic and intuitive strategies (right-thinkers) tend towards non-linear paths.…

  8. Hypermedia for Teaching--A European Collaborative Venture.

    ERIC Educational Resources Information Center

    Barker, Philip; Bartolome, Antonio

    The "Hypermedia for Teaching" project is a European collaborative venture designed to produce a hypermedia learning package that is published on CD-ROM. Two versions of the package are to be developed. One of these is intended to be used on a multimedia personal computer (MPC), while the other is to be used in conjunction with…

  9. Hypermedia: The Integrated Learning Environment. Fastback 339.

    ERIC Educational Resources Information Center

    Wishnietsky, Dan H.

    Hypermedia is not a single technology; it is an integrated electronic environment that combines text, audio, and video into one large file. Users can explore information about a subject using several technologies at the same time. Although the technical foundation for hypermedia was established in the early 1970s, it was not until the late 1980s…

  10. Integrating Existing Applications in Hypermedia Learning Material (General Issues & Experiences with OLE Technology).

    ERIC Educational Resources Information Center

    Borst Pauwels, H. W. J.; And Others

    The integration of existing applications in hypermedia environments is a promising approach towards more flexible and user-friendly hypermedia learning materials. A hypermedia courseware editor, called HyDE (Hypermedia Document Editor) was developed using Microsoft Windows TM OLE technology. OLE (object Linking and Embedding) stands for an…

  11. SEPEC conference proceedings: Hypermedia and Information Reconstruction. Aerospace applications and research directions

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Papers presented at the conference on hypermedia and information reconstruction are compiled. The following subject areas are covered: real-world hypermedia projects, aerospace applications, and future directions in hypermedia research and development.

  12. A Folksonomy-Based Lightweight Resource Annotation Metadata Schema for Personalized Hypermedia Learning Resource Delivery

    ERIC Educational Resources Information Center

    Lau, Simon Boung-Yew; Lee, Chien-Sing; Singh, Yashwant Prasad

    2015-01-01

    With the proliferation of social Web applications, users can now collaboratively author, share and access hypermedia learning resources, contributing to richer learning experiences outside formal education. These resources may or may not be educational. However, they can be harnessed for educational purposes by adapting and personalizing them to…

  13. Learning and Navigation Assistance in a Hypermedia

    ERIC Educational Resources Information Center

    Khentout, Chabane; Harous, Saad; Douidi, Lamri; Djoudi, Mahieddine

    2006-01-01

    Navigating through hypermedia the user faces problems of locating oneself with respect to space and time. That is why there is a need to develop tools that can help the user locate himself to see where he has been browsing through the net during a particular navigation session through hypermedia. It is needed to offer the user a map of the visited…

  14. Teaching Hypertext and Hypermedia through the Web.

    ERIC Educational Resources Information Center

    de Bra, Paul M. E.

    This paper describes a World Wide Web-based introductory course titled "Hypermedia Structures and Systems," offered as an optional part of the curriculum in computing science at the Eindhoven University of Technology (Netherlands). The technical environment for the current (1996) edition of the course is presented, which features…

  15. Effective Levels of Adaptation to Different Types of Users in Interactive Museum Systems.

    ERIC Educational Resources Information Center

    Paterno, F.; Mancini, C.

    2000-01-01

    Discusses user interaction with museum application interfaces and emphasizes the importance of adaptable and adaptive interfaces to meet differing user needs. Considers levels of support that can be given to different users during navigation of museum hypermedia information, using examples from the Web site for the Marble Museum (Italy).…

  16. An introduction to interactive hypermedia.

    PubMed

    Lynch, P J; Jaffe, C C

    1990-01-01

    Current computers can create and display documents that incorporate a variety of audiovisual media, and can be organized to allow the user, guided by curiosity and not by a fixed path through the material, to move through the information in non-linear pathways. These hypermedia documents and the concept of hypertext offer significant new possibilities for the creation of educational materials for the biomedical sciences. If the full capabilities of the computer are to be used to enhance the educational experience for learners, computer professionals need to collaborate with publishing and teaching professionals. Biomedical communications professionals can and should play a role in establishing and evaluating hypermedia documents for medical education.

  17. Individual and small group interactions in learning to teach with a hypermedia case

    NASA Astrophysics Data System (ADS)

    Chung, Mi-Lee Ahn

    The purpose of this study was to investigate the similarities and differences of individual and small group preservice teachers' interactions with a hypermedia case. Preservice teachers' interactions with a hypermedia case were defined in terms of their (1) goals and perception of accomplishments of the goals, (2) use of features of the hypermedia case, and (3) types of questions and conflicts raised. Two individuals and two small groups of three preservice teachers participated by interacting with the hypermedia case which was developed to illustrate conceptual change science teaching in an elementary classroom. Most of the previous studies in this area have addressed large group use of hypermedia cases, and this study attempted to address the gap in the literature related to different social contexts, individuals and small groups, from the constructivist perspective. The assumptions of symbolic interactionism guided data collection from think-alouds and interviews. These multiple sources of data were used to understand the participants' construction of knowledge; data were analyzed and interpreted by a process of analytic induction. The major assertion was that the preservice teachers perceived the hypermedia case to be like a tool to link theory and practice of teaching. Three sub-assertions, and several supporting categories, also emerged from the data. These findings indicated that group learning experiences with the hypermedia case were more valuable than those of individuals. In general, preservice teachers benefited from learning how to teach with the hypermedia case in both settings. However, the individuals were not as satisfied as those in small groups, and the members of small groups interacted more actively with the hypermedia case as well as with the peers. The results of this study suggest that effective use of hypermedia cases takes place in a community of learners where the learners share the context and can draw upon the resources afforded by the

  18. Using hypermedia to develop an intelligent tutorial/diagnostic system for the Space Shuttle Main Engine Controller Lab

    NASA Technical Reports Server (NTRS)

    Oreilly, Daniel; Williams, Robert; Yarborough, Kevin

    1988-01-01

    This is a tutorial/diagnostic system for training personnel in the use of the Space Shuttle Main Engine Controller (SSMEC) Simulation Lab. It also provides a diagnostic capable of isolating lab failures at least to the major lab component. The system was implemented using Hypercard, which is an program of hypermedia running on Apple Macintosh computers. Hypercard proved to be a viable platform for the development and use of sophisticated tutorial systems and moderately capable diagnostic systems. This tutorial/diagnostic system uses the basic Hypercard tools to provide the tutorial. The diagnostic part of the system uses a simple interpreter written in the Hypercard language (Hypertalk) to implement the backward chaining rule based logic commonly found in diagnostic systems using Prolog. Some of the advantages of Hypercard in developing this type of system include sophisticated graphics, animation, sound and voice capabilities, its ability as a hypermedia tool, and its ability to include digitized pictures. The major disadvantage is the slow execution time for evaluation of rules (due to the interpretive processing of the language). Other disadvantages include the limitation on the size of the cards, that color is not supported, that it does not support grey scale graphics, and its lack of selectable fonts for text fields.

  19. A Critical Analysis of Hypermedia and Virtual Learning Environments.

    ERIC Educational Resources Information Center

    Oliver, Kevin M.

    The use of hypermedia in education is supported by cognitive flexibility theory which indicates transfer of knowledge to real-world settings is improved when that material is learned in a case-based, associative network emphasizing complexity and links to related information. Hypermedia is further assumed to benefit education, because it resembles…

  20. Impact of Adapted Hypermedia on Undergraduate Students' Learning of Astronomy in an Elearning Environment

    NASA Astrophysics Data System (ADS)

    Zuel, Brian

    The purpose of this dissertation was to examine the effectiveness of matching learners' optimal learning styles to their overall knowledge retention. The study attempted to determine if learners who are placed in an online learning environment that matches their optimal learning styles will retain the information at a higher rate than those learners who are not in an adapted learning environment. There were 56 participants that took one of two lessons; the first lesson was textual based, had no hypertext, and was not influenced heavily by the coherence principle, while the second lesson was multimedia based utilizing hypermedia guided by the coherence principle. Each participant took Felder and Soloman's (1991, 2000) Index of Learning Styles (ILS) questionnaire and was classified using the Felder-Silverman Learning Style Model (FSLSM; 1998) into four individual categories. Groups were separated using the Visual/Verbal section of the FSLSM with 55% (n = 31) of participants going to the adapted group, and 45% (n =25) of participants going to the non-adapted group. Each participant completed an immediate posttest directly after the lesson and a retention posttest a week later. Several repeated measures MANOVA tests were conducted to measure the significance of differences in the tests between groups and within groups. Repeated measures MANOVA tests were conducted to determine if significance existed between the immediate posttest results and the retention posttest results. Also, participants were asked their perspectives if the lesson type they received was beneficial to their perceived learning of the material. Of the 56 students who took part in this study, 31 students were placed in the adapted group and 25 in the non-adapted group based on outcomes of the ILS and the FLSSM. No significant differences were found between groups taking the multimedia lesson and the textual lesson in the immediate posttest. No significant differences were found between the adapted and

  1. Perceived Value of Educational Hypermedia: An Exploratory Study

    ERIC Educational Resources Information Center

    Gao, Yuan; Wu, Xiaoyu

    2010-01-01

    This paper explores the idea of perceived value of educational hypermedia by extending prior research in advertising and information systems. It proposes that the value of a course support site comes from both its information content and users' experience when they visit the site. The cognitive antecedents of a site's perceived value include…

  2. Enhancing L2 Reading Comprehension with Hypermedia Texts: Student Perceptions

    ERIC Educational Resources Information Center

    Garrett-Rucks, Paula; Howles, Les; Lake, William M.

    2015-01-01

    This study extends current research about L2 hypermedia texts by investigating the combined use of audiovisual features including: (a) Contextualized images, (b) rollover translations, (c) cultural information, (d) audio explanations and (e) comprehension check exercises. Specifically, student perceptions of hypermedia readings compared to…

  3. Merging the Internet and Hypermedia in the English Language Arts.

    ERIC Educational Resources Information Center

    Reed, W. Michael; Wells, John G.

    1997-01-01

    Discussion of hypermedia and computer-mediated communication focuses on a project that merges a language arts Internet resource with a hypermedia-based knowledge construction approach to learning. Highlights include constructing a HyperCard-based program on Shakespeare's "Hamlet," gophers and search engines, downloading, collaborative…

  4. Adaptive Social Learning Based on Crowdsourcing

    ERIC Educational Resources Information Center

    Karataev, Evgeny; Zadorozhny, Vladimir

    2017-01-01

    Many techniques have been developed to enhance learning experience with computer technology. A particularly great influence of technology on learning came with the emergence of the web and adaptive educational hypermedia systems. While the web enables users to interact and collaborate with each other to create, organize, and share knowledge via…

  5. Hypermedia in Vocational Learning: A Hypermedia Learning Environment for Training Management Skills

    ERIC Educational Resources Information Center

    Konradt, Udo

    2004-01-01

    A learning environment is defined as an arrangement of issues, methods, techniques, and media in a given domain. Besides temporal and spatial features a learning environment considers the social situation in which learning takes place. In (hypermedia) learning environments the concept of exploration and the active role of the learner is…

  6. Exploring Metacognitive Strategies and Hypermedia Annotations on Foreign Language Reading

    ERIC Educational Resources Information Center

    Shang, Hui-Fang

    2017-01-01

    The effective use of reading strategies has been recognized as an important way to increase reading comprehension in hypermedia environments. The purpose of the study was to explore whether metacognitive strategy use and access to hypermedia annotations facilitated reading comprehension based on English as a foreign language students' proficiency…

  7. Online Metacognitive Strategies, Hypermedia Annotations, and Motivation on Hypertext Comprehension

    ERIC Educational Resources Information Center

    Shang, Hui-Fang

    2016-01-01

    This study examined the effect of online metacognitive strategies, hypermedia annotations, and motivation on reading comprehension in a Taiwanese hypertext environment. A path analysis model was proposed based on the assumption that if English as a foreign language learners frequently use online metacognitive strategies and hypermedia annotations,…

  8. Hypermedia as medium

    NASA Technical Reports Server (NTRS)

    Dede, Christopher J.

    1990-01-01

    Claims and rebuttals that hypermedia (the associative, nonlinear interconnection of multimedia materials) is a fundamentally innovative means of thinking and communicating are described. This representational architecture has many advantages that make it a major advance over other media; however, it also has several intrinsic problems that severly limits its effectiveness as a medium. These advantages and limits in applications are discussed.

  9. Enhancing Effective Chemistry Learning through Hypermedia Instructional Mode of Delivery

    ERIC Educational Resources Information Center

    Abanikannda, Mutahir Oluwafemi

    2016-01-01

    This study provides a framework for the production of Hypermedia Instructional package. It also assessed the effectiveness of hypermedia instructional mode of delivery on students? performance in Chemistry. This is with a view of improving the learning of Chemistry which may eventually help to improve students? performance. The developmental study…

  10. On-demand hypermedia/multimedia service over broadband networks

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bouras, C.; Kapoulas, V.; Spirakis, P.

    1996-12-31

    In this paper we present a unified approach for delivering hypermedia/multimedia objects over broadband networks. Documents are stored in various multimedia servers, while the inline data may reside in their own media servers, attached to the multimedia servers. The described service consists of several multimedia servers and a set of functions that intend to present to the end user interactive information in real-time. Users interact with the service requesting multimedia documents on demand. Various media streams are transmitted over different parallel connections according lo their transmission requirements. The hypermedia documents are structured using a hypermedia markup language that keeps informationmore » of the spatiotemporal relationships among document`s media components. In order to deal with the variant network behavior, buffering manipulation mechanisms and grading of the transmitted media quality techniques are proposed to smooth presentation and synchronization anomalies.« less

  11. Use of Visual Metaphors for Navigation in Educational Hypermedia: Effects on the Navigational Performance

    ERIC Educational Resources Information Center

    Firat, Mehmet; Kabakci, Isil

    2010-01-01

    The interactional feature of hypermedia that allows high-level student-control is considered as one of the most important advantages that hypermedia provides for learning and teaching. However, high-level student control in hypermedia might not always lead to high-level learning performance. The learner is likely to experience navigation problems…

  12. Integrating knowledge and control into hypermedia-based training environments: Experiments with HyperCLIPS

    NASA Technical Reports Server (NTRS)

    Hill, Randall W., Jr.

    1990-01-01

    The issues of knowledge representation and control in hypermedia-based training environments are discussed. The main objective is to integrate the flexible presentation capability of hypermedia with a knowledge-based approach to lesson discourse management. The instructional goals and their associated concepts are represented in a knowledge representation structure called a 'concept network'. Its functional usages are many: it is used to control the navigation through a presentation space, generate tests for student evaluation, and model the student. This architecture was implemented in HyperCLIPS, a hybrid system that creates a bridge between HyperCard, a popular hypertext-like system used for building user interfaces to data bases and other applications, and CLIPS, a highly portable government-owned expert system shell.

  13. A Psychology of Hypermedia: A Conceptual Framework for R&D.

    ERIC Educational Resources Information Center

    Borsook, Terry K.; Higginbotham-Wheat, Nancy

    This paper explores the insights that psychology can offer in shedding light on why hypermedia may work and thus in suggesting fruitful areas for future research. The philosophy underlying the paper is that research into the instructional efficacy of hypermedia should begin with a knowledge and appreciation of relevant psychological phenomena.…

  14. Hypermedia and Research Methodology: An Associative Research Model. Final Report.

    ERIC Educational Resources Information Center

    City Univ. of New York, NY. Bernard Baruch Coll.

    The purpose of the project described in this three-part report was to test the value of hypermedia for library instruction. The project included the development of a hypermedia program built around a marketing topic; implementation and testing of the program with one group of students assigned to use the new program; evaluation of the project by…

  15. Towards Individualized Online Learning: The Design and Development of an Adaptive Web Based Learning Environment

    ERIC Educational Resources Information Center

    Inan, Fethi A.; Flores, Raymond; Ari, Fatih; Arslan-Ari, Ismahan

    2011-01-01

    The purpose of this study was to document the design and development of an adaptive system which individualizes instruction such as content, interfaces, instructional strategies, and resources dependent on two factors, namely student motivation and prior knowledge levels. Combining adaptive hypermedia methods with strategies proposed by…

  16. Autonomy Supported, Learner-Controlled or System-Controlled Learning in Hypermedia Environments and the Influence of Academic Self-Regulation Style

    ERIC Educational Resources Information Center

    Gorissen, Chantal J. J.; Kester, Liesbeth; Brand-Gruwel, Saskia; Martens, Rob

    2015-01-01

    This study focuses on learning in three different hypermedia environments that either support autonomous learning, learner-controlled learning or system-controlled learning and explores the mediating role of academic self-regulation style (ASRS; i.e. a macro level of motivation) on learning. This research was performed to gain more insight in the…

  17. Recent Literature Shows Accelerated Growth in Hypermedia Tools: An Annotated Bibliography.

    ERIC Educational Resources Information Center

    Gabbard, Ralph

    1994-01-01

    Presents an annotated bibliography of materials on hypertext/hypermedia. Information available on the World Wide Web is described; journals that cover hypermedia are listed; and the main bibliography is divided into 3 sections on general hypertext applications (17 titles), DOS/Windows applications (17 titles), and HyperCard applications (18…

  18. Students' Navigation Patterns in the Interaction with a Mechanics Hypermedia Program

    ERIC Educational Resources Information Center

    Rezende, Flavia; de Souza Barros, Susana

    2008-01-01

    This study investigates the interaction of a group of freshmen enrolled in a Pre Service Physics Teacher Training Course with a mechanics hypermedia program. Data were obtained to discuss hypertextual navigation guided by the following questions: (i) How can the students' navigation in this hypermedia program be characterized? (ii) How does this…

  19. The Effectiveness of Computer-Based Hypermedia Teaching Modules for Radiology Residents.

    ERIC Educational Resources Information Center

    Azevedo, Roger; And Others

    This paper explains the rationale for utilizing computer-based, hypermedia tutorials for radiology education and presents the results of a field test of this educational technique. It discusses the development of the hypermedia tutorials at Montreal General Hospital (Quebec, Canada) in 1991-92 and their use in the radiology residency program. The…

  20. The Effects of Gender and Dominant Mental Processes on Hypermedia Learning

    ERIC Educational Resources Information Center

    Ellis, Holly; Howard, W. Gary; Donofrio, Heather H.

    2012-01-01

    The effects of gender and dominant mental process on learning is an area of increased interest among educators. This study was designed to explore those effects on hypermedia learning. The hypermedia module was created using a modified hierarchical structure, and a pre-test/post-test was conducted. The Myers-Briggs Type Indicator (MBTI) was…

  1. Hypermedia 1990 structured Hypertext tutorial

    NASA Technical Reports Server (NTRS)

    Johnson, J. Scott

    1990-01-01

    Hypermedia 1990 structured Hypertext tutorial is presented in the form of view-graphs. The following subject areas are covered: structured hypertext; analyzing hypertext documents for structure; designing structured hypertext documents; creating structured hypertext applications; structuring service and repair documents; maintaining structured hypertext documents; and structured hypertext conclusion.

  2. Labyrinth, An Abstract Model for Hypermedia Applications. Description of its Static Components.

    ERIC Educational Resources Information Center

    Diaz, Paloma; Aedo, Ignacio; Panetsos, Fivos

    1997-01-01

    The model for hypermedia applications called Labyrinth allows: (1) the design of platform-independent hypermedia applications; (2) the categorization, generalization and abstraction of sparse unstructured heterogeneous information in multiple and interconnected levels; (3) the creation of personal views in multiuser hyperdocuments for both groups…

  3. Examining Hypermedia Learning: The Role of Cognitive Load and Self-Regulated Learning

    ERIC Educational Resources Information Center

    Moos, Daniel

    2013-01-01

    Distinct theoretical perspectives, Cognitive Load Theory and Self-Regulated Learning (SRL) theory, have been used to examine individual differences the challenges faced with hypermedia learning. However, research has tended to use these theories independently, resulting in less robust explanations of hypermedia learning. This study examined the…

  4. An Adaptive E-Learning System Based on Students' Learning Styles: An Empirical Study

    ERIC Educational Resources Information Center

    Drissi, Samia; Amirat, Abdelkrim

    2016-01-01

    Personalized e-learning implementation is recognized as one of the most interesting research areas in the distance web-based education. Since the learning style of each learner is different one must fit e-learning with the different needs of learners. This paper presents an approach to integrate learning styles into adaptive e-learning hypermedia.…

  5. Computer simulations in teaching physics: Development and implementation of a hypermedia system for high school teachers

    NASA Astrophysics Data System (ADS)

    da Silva, A. M. R.; de Macêdo, J. A.

    2016-06-01

    On the basis of the technological advancement in the middle and the difficulty of learning by the students in the discipline of physics, this article describes the process of elaboration and implementation of a hypermedia system for high school teachers involving computer simulations for teaching basic concepts of electromagnetism, using free tool. With the completion and publication of the project there will be a new possibility of interaction of students and teachers with the technology in the classroom and in labs.

  6. Assessment of Cognitive Style to Examine Students' Use of Hypermedia within Historic Costume.

    ERIC Educational Resources Information Center

    Frey, Diane; Simonson, Michael

    1993-01-01

    Cognitive style of 70 students in fashion merchandising or education was compared to their choice of media in a hypermedia lesson on costume using HyperCard. Students used hypermedia effectively to accommodate preferred style; 56% chose visual, 30% text, and 14% auditory. (SK)

  7. Information Comparisons in Example-Based Hypermedia Environments: Supporting Learners with Processing Prompts and an Interactive Comparison Tool

    ERIC Educational Resources Information Center

    Gerjets, Peter; Scheiter, Katharina; Schuh, Julia

    2008-01-01

    Global comparisons of learning from hypertext/hypermedia and traditional presentation formats like text have yet failed to show major advantages concerning the effectiveness of hypermedia learning. Thus, it is proposed in the current paper to evaluate hypermedia environments more specifically with regard to their potential to implement and support…

  8. AHA! Version 2.0: More Adaptation Flexibility for Authors.

    ERIC Educational Resources Information Center

    De Bra, Paul; Aerts, Ad; Smits, David; Stash, Natalia

    AHA! is a simple Web-based adaptive hypermedia system. Because of this simplicity it has been studied and experimented with in several research groups. This paper identifies shortcomings in AHA! and presents AHA! version 2.0 which tries to overcome the known problems with AHA! while maintaining its biggest asset: simplicity. The paper illustrates…

  9. A Hypermedia Environment To Explore and Negotiate Students' Conceptions: Animation of the Solution Process of Table Salt.

    ERIC Educational Resources Information Center

    Ebenezer, Jazlin V.

    2001-01-01

    Describes the characteristics and values of hypermedia for learning chemistry. Reports on how a hypermedia environment was used to explore a group of 11th grade chemistry students' conceptions of table salt dissolving in water. Indicates that a hypermedia environment can be used to explore, negotiate, and assess students' conceptions of…

  10. Knowledge Construction and Knowledge Representation in High School Students' Design of Hypermedia Documents

    ERIC Educational Resources Information Center

    Chen, Pearl; McGrath, Diane

    2003-01-01

    This study documented the processes of knowledge construction and knowledge representation in high school students' hypermedia design projects. Analysis of knowledge construction in linking and structural building yielded distinct types and subtypes of hypermedia documents, which were characterized by four features of knowledge representation: (a)…

  11. The Relationship between the Learning Strategies and Learning Styles in a Hypermedia Environment.

    ERIC Educational Resources Information Center

    Liu, Min; Reed, W. Michael

    Different learning strategies that are used by field-independent (FI) and field-dependent (FD) people in a hypermedia-assisted instructional setting were studied with 63 international college students for whom English was a second language. The treatment was a semantic network-based hypermedia-assisted language-learning environment to help…

  12. Millikan Lecture 1992: Hypermedia and the knowing of physics: Standing upon the shoulders of giants

    NASA Astrophysics Data System (ADS)

    Fuller, Robert G.

    1993-04-01

    Hypermedia is defined and its roots briefly discussed. Models of knowing physics and of intrinsically motivating instruction are presented. Uses of hypermedia to increase the knowing of physics and the motivation of learners are proposed.

  13. Hypermedia Laboratory, Defense Applied Information Technology Center; Review for 1988

    DTIC Science & Technology

    1988-12-01

    Information System (DGIS): The Department of Defense Microcomputer User’s Gateway to the World;" Microcomputers for Information Management : An International...accessing. "Knowledge Gateways: The Building Blocks." Information Processing & Management , Volume 24, Number 4, pp. 459-468, 1988. Donald T. Hawkins...intelligence and hypermedia. This activity is managed by the Defense Technical Information Center (DTIC). Much of our development at this point is

  14. Educational Multimedia/Hypermedia and Telecommunications, 1997. Proceedings of ED-MEDIA/ED-TELECOM 97--World Conference on Educational Multimedia/Hypermedia and Educational Telecommunications (Calgary, Canada, June 14-19, 1997). Volumes I and II.

    ERIC Educational Resources Information Center

    Muldner, Tomasz, Ed.; Reeves, Thomas C., Ed.

    This collection presents papers pertaining to the wide area of educational multimedia/hypermedia and telecommunications. The conference serves as a forum for the dissemination of information on the research, development, and applications in all areas of multimedia/hypermedia and telecommunications in education across all disciplines and levels.…

  15. Life sciences on-line: A study in hypermedia application

    NASA Technical Reports Server (NTRS)

    Christman, Linda A.; Hoang, Nam V.; Proctor, David R.

    1990-01-01

    The main objective was to determine the feasibility of using a computer-based interactive information recall module for the Life Sciences Project Division (LSPD) at NASA, Johnson Space Center. LSPD personnel prepare payload experiments to test and monitor physiological functions in zero gravity. Training refreshers and other types of online help are needed to support personnel in their tasks during mission testing and in flight. Results of a survey of other hypermedia and multimedia developers and lessons learned by the developer of the LSPD prototype module are presented. Related issues and future applications are also discussed and further hypermedia development within the LSPD is recommended.

  16. Integrating hypermedia into the environmental education setting: Developing a program and evaluating its effect

    NASA Astrophysics Data System (ADS)

    Parker, Tehri Davenport

    1997-09-01

    This study designed, implemented, and evaluated an environmental education hypermedia program for use in a residential environmental education facility. The purpose of the study was to ascertain whether a hypermedia program could increase student knowledge and positive attitudes toward the environment and environmental education. A student/computer interface, based on the theory of social cognition, was developed to direct student interactions with the computer. A quasi-experimental research design was used. Students were randomly assigned to either the experimental or control group. The experimental group used the hypermedia program to learn about the topic of energy. The control group received the same conceptual information from a teacher/naturalist. An Environmental Awareness Quiz was administered to measure differences in the students' cognitive understanding of energy issues. Students participated in one on one interviews to discuss their attitudes toward the lesson and the overall environmental education experience. Additionally, members of the experimental group were tape recorded while they used the hypermedia program. These tapes were analyzed to identify aspects of the hypermedia program that promoted student learning. The findings of this study suggest that computers, and hypermedia programs, can be integrated into residential environmental education facilities, and can assist environmental educators in meeting their goals for students. The study found that the hypermedia program was as effective as the teacher/naturalist for teaching about environmental education material. Students who used the computer reported more positive attitudes toward the lesson on energy, and thought that they had learned more than the control group. Students in the control group stated that they did not learn as much as the computer group. The majority of students had positive attitudes toward the inclusion of computers in the camp setting, and stated that they were a good

  17. Toward a Web Based Environment for Evaluation and Design of Pedagogical Hypermedia

    ERIC Educational Resources Information Center

    Trigano, Philippe C.; Pacurar-Giacomini, Ecaterina

    2004-01-01

    We are working on a method, called CEPIAH. We propose a web based system used to help teachers to design multimedia documents and to evaluate their prototypes. Our current research objectives are to create a methodology to sustain the educational hypermedia design and evaluation. A module is used to evaluate multimedia software applied in…

  18. The use of hypermedia to increase the productivity of software development teams

    NASA Technical Reports Server (NTRS)

    Coles, L. Stephen

    1991-01-01

    Rapid progress in low-cost commercial PC-class multimedia workstation technology will potentially have a dramatic impact on the productivity of distributed work groups of 50-100 software developers. Hypermedia/multimedia involves the seamless integration in a graphical user interface (GUI) of a wide variety of data structures, including high-resolution graphics, maps, images, voice, and full-motion video. Hypermedia will normally require the manipulation of large dynamic files for which relational data base technology and SQL servers are essential. Basic machine architecture, special-purpose video boards, video equipment, optical memory, software needed for animation, network technology, and the anticipated increase in productivity that will result for the introduction of hypermedia technology are covered. It is suggested that the cost of the hardware and software to support an individual multimedia workstation will be on the order of $10,000.

  19. Authoring of Adaptive Computer Assisted Assessment of Free-Text Answers

    ERIC Educational Resources Information Center

    Alfonseca, Enrique; Carro, Rosa M.; Freire, Manuel; Ortigosa, Alvaro; Perez, Diana; Rodriguez, Pilar

    2005-01-01

    Adaptation techniques can be applied not only to the multimedia contents or navigational possibilities of a course, but also to the assessment. In order to facilitate the authoring of adaptive free-text assessment and its integration within adaptive web-based courses, Adaptive Hypermedia techniques and Free-text Computer Assisted Assessment are…

  20. An Approach to the Evaluation of Hypermedia.

    ERIC Educational Resources Information Center

    Knussen, Christina; And Others

    1991-01-01

    Discusses methods that may be applied to the evaluation of hypermedia, based on six models described by Lawton. Techniques described include observation, self-report measures, interviews, automated measures, psychometric tests, checklists and criterion-based techniques, process models, Experimentally Measuring Usability (EMU), and a naturalistic…

  1. Multiple Views, Contexts, and Symbol Systems in Learning with Hypertext/Hypermedia: A Critical Review of Research.

    ERIC Educational Resources Information Center

    Tergan, Sigmar-Olaf

    1997-01-01

    Reviews research on the effectiveness of hypertext/hypermedia-based learning and concludes that presenting subject matter from different perspectives, in multiple contexts, and in multiple codes does not automatically contribute to higher performance but may when instructional scaffolding is provided. The additional cognitive load may actually…

  2. Why Is Externally-Facilitated Regulated Learning More Effective than Self-Regulated Learning with Hypermedia?

    ERIC Educational Resources Information Center

    Azevedo, Roger; Moos, Daniel C.; Greene, Jeffrey A.; Winters, Fielding I.; Cromley, Jennifer G.

    2008-01-01

    We examined how self-regulated learning (SRL) and externally-facilitated self-regulated learning (ERL) differentially affected adolescents' learning about the circulatory system while using hypermedia. A total of 128 middle-school and high school students with little prior knowledge of the topic were randomly assigned to either the SRL or ERL…

  3. Developing a clinical hypermedia corpus: experiences from the use of a practice-centered method.

    PubMed Central

    Timpka, T.; Nyce, J. M.; Sjöberg, C.; Hedblom, P.; Lindblom, P.

    1992-01-01

    This paper outlines a practice-centered method for creation of a hypermedia corpus. It also describes experiences with creating such a corpus of information to support interprofessional work at a Primary Healthcare Center. From these experiences, a number of basic issues regarding information systems development within medical informatics will be discussed. PMID:1482924

  4. User-Centered Indexing for Adaptive Information Access

    NASA Technical Reports Server (NTRS)

    Chen, James R.; Mathe, Nathalie

    1996-01-01

    We are focusing on information access tasks characterized by large volume of hypermedia connected technical documents, a need for rapid and effective access to familiar information, and long-term interaction with evolving information. The problem for technical users is to build and maintain a personalized task-oriented model of the information to quickly access relevant information. We propose a solution which provides user-centered adaptive information retrieval and navigation. This solution supports users in customizing information access over time. It is complementary to information discovery methods which provide access to new information, since it lets users customize future access to previously found information. It relies on a technique, called Adaptive Relevance Network, which creates and maintains a complex indexing structure to represent personal user's information access maps organized by concepts. This technique is integrated within the Adaptive HyperMan system, which helps NASA Space Shuttle flight controllers organize and access large amount of information. It allows users to select and mark any part of a document as interesting, and to index that part with user-defined concepts. Users can then do subsequent retrieval of marked portions of documents. This functionality allows users to define and access personal collections of information, which are dynamically computed. The system also supports collaborative review by letting users share group access maps. The adaptive relevance network provides long-term adaptation based both on usage and on explicit user input. The indexing structure is dynamic and evolves over time. Leading and generalization support flexible retrieval of information under similar concepts. The network is geared towards more recent information access, and automatically manages its size in order to maintain rapid access when scaling up to large hypermedia space. We present results of simulated learning experiments.

  5. The Effect of Being Hypermedia Designers on Elementary School Students' Motivation and Learning of Design Knowledge.

    ERIC Educational Resources Information Center

    Liu, Min; Pedersen, Susan

    Current educational theory and practice clearly show that project-based instruction has the potential to enhance learning. Preliminary findings on one type of project-based learning in which students take on the role of hypermedia designers support this claim. This study examined the effect of being hypermedia designers on fourth-graders'…

  6. A multi-interface adaptive hypermedia system to promote consumer-provider partnership in chronic disease management.

    PubMed

    Lundström, Maria; Warren, Jim; Jones, Sara; Chung, Frank

    2003-01-01

    Much of chronic disease management depends on active partnership of consumer and provider. Our system promotes diabetes management through profiling and adaptive support of both consumer and provider. We use a University Podiatry Clinic and diabetes consumer information portal as inter-related contexts that share profile information.

  7. A Multi-interface Adaptive Hypermedia System to Promote Consumer-Provider Partnership in Chronic Disease Management

    PubMed Central

    Lundström, Maria; Warren, Jim; Jones, Sara; Chung, Frank

    2003-01-01

    Much of chronic disease management depends on active partnership of consumer and provider. Our system promotes diabetes management through profiling and adaptive support of both consumer and provider. We use a University Podiatry Clinic and diabetes consumer information portal as inter-related contexts that share profile information. PMID:14728425

  8. An Analysis of Student Hypermedia Navigation and Learning

    ERIC Educational Resources Information Center

    Epp, Erik Minh

    2010-01-01

    As society's interactions with web technology mature from novelty to familiarity and finally into transparence for users, it becomes important to reexamine what modern students are taking from their experiences with educational technology. Students in a physical chemistry laboratory course interacted with a hypermedia learning environment as part…

  9. Student and In-Service Teachers' Acceptance of Spatial Hypermedia in Their Teaching: The Case of Hypersea

    ERIC Educational Resources Information Center

    Koutromanos, George; Styliaras, Georgios; Christodoulou, Sotiris

    2015-01-01

    The aim of this study was to use the Technology Acceptance Model (TAM) in order to investigate the factors that influence student and in-service teachers' intention to use a spatial hypermedia application, the HyperSea, in their teaching. HyperSea is a modern hypermedia environment that takes advantage of space in order to display content nodes…

  10. Middle School Hypermedia Composition: A Qualitative Case Study

    ERIC Educational Resources Information Center

    Garthwait, Abigail

    2007-01-01

    During a six-month naturalistic study, the author conducted an ethnographic examination of a seventh grade hypermedia unit. Beginning with the global question, "In what ways are computers used to support the education of middle school students?" the researcher coded and analyzed observations, interviews and projects. Three themes emerged: the…

  11. Elaborated Resources: An Instructional Design Strategy for Hypermedia.

    ERIC Educational Resources Information Center

    Rezabek, Randall H.; Ragan, Tillman J.

    The concept of hypertext was introduced by Ted Nelson in 1965, but only recently has the widely available technology caught up with the idea. The new generation of microcomputers featuring large internal memories, graphic interfaces, and large data storage capacities have made the commercial development of hypertext/hypermedia software possible. A…

  12. Hypermedia Ethnography in Educational Settings: Possibilities and Challenges

    ERIC Educational Resources Information Center

    Coffey, Amanda; Renold, Emma; Dicks, Bella; Soyinka, Bambo; Mason, Bruce

    2006-01-01

    This paper considers some of the methodological implications of undertaking and representing multimedia and digital, ethnographic work. It explores some of the challenges and opportunities of working with and across a range of media, and explores some of the consequences of bringing hypermedia applications to ethnographic work. The paper draws on…

  13. Don't forget the learner: an essential aspect for developing effective hypermedia online learning in continuing medical education.

    PubMed

    Sandars, John; Homer, Matthew; Walsh, Kieran; Rutherford, Alaster

    2012-03-01

    There is increasing use of hypermedia online learning in continuing medical education (CME) that presents the learner with a wide range of different learning resources, requiring the learner to use self-regulated learning (SRL) skills. This study is the first to apply an SRL perspective to understand how learners engage with hypermedia online learning in CME. We found that the main SRL skills used by learners were use of strategies and monitoring. The increasing use of strategies was associated with increasing interest in the topic and with increasing satisfaction with the learning experience. Further research is recommended to understand SRL processes and its impact on learning in other aspects of hypermedia online learning across the different phases of medical education. Research is also recommended to implement and evaluate the learning impact of a variety of approaches to develop the SRL skills of hypermedia online learners in CME.

  14. The Role of Goal Structure in Undergraduates' Use of Self-Regulatory Processes in Two Hypermedia Learning Tasks

    ERIC Educational Resources Information Center

    Moos, Daniel C.; Azevedo, Roger

    2006-01-01

    We collected think-aloud and posttest data from 60 undergraduates to examine whether they used different proportions of self-regulated learning (SRL) variables in two related learning tasks about science topics while using a hypermedia environment. We also manipulated the goal structure of the two hypermedia learning tasks to explore whether the…

  15. The Temporal and Dynamic Nature of Self-Regulatory Processes during Independent and Externally Assisted Hypermedia Learning

    ERIC Educational Resources Information Center

    Johnson, Amy M.; Azevedo, Roger; D'Mello, Sidney K.

    2011-01-01

    This study examined the temporal and dynamic nature of students' self-regulatory processes while learning about the circulatory system with hypermedia. A total of 74 undergraduate students were randomly assigned to 1 of 2 conditions: independent learning or externally assisted learning. Participants in the independent learning condition used a…

  16. Empirical Evaluation of Adaptive Annotation in Hypermedia.

    ERIC Educational Resources Information Center

    Specht, Marcus

    Empirical evaluations of learning with hypertext have shown contradictory results. Adaptive hypertext was introduced to solve some problems when learning with hypertext. This paper reports on two empirical studies comparing different forms of adaptive hypertext. In the first experiment, four treatments were realized by a combination of adaptive…

  17. Hypermedia as an Educational Technology: A Review of the Quantitative Research Literature on Learner Comprehension, Control, and Style.

    ERIC Educational Resources Information Center

    Dillon, Andrew; Gabbard, Ralph

    1998-01-01

    Published studies of hypermedia as an educational technology that have emphasized quantitative and empirical assessment of outcomes were reviewed. The evidence to date suggests that hypermedia benefits in education are limited to learning tasks depending on repeated manipulation and searching of information. Implications for instruction and…

  18. A Bibliography on Hypertext and Hypermedia with Selected Annotations.

    ERIC Educational Resources Information Center

    Franklin, Carl

    1990-01-01

    The first of 2 parts, this bibliography contains 233 references to materials dealing with hypertext and hypermedia. Entries are presented in the following categories: alternatives to HyperCard; bibliographies; biographies; books and book reviews; dictionaries; hardware; interviews; library applications; optical disk-related; theoretical and…

  19. Adolescents' Use of Self-Regulatory Processes and Their Relation to Qualitative Mental Model Shifts while Using Hypermedia

    ERIC Educational Resources Information Center

    Greene, Jeffrey Alan; Azevedo, Roger

    2007-01-01

    This study examined 148 adolescents' use of self-regulated learning (SRL) processes when learning about the circulatory system using hypermedia. We examined participants' verbal protocols to determine the relationship between SRL processes and qualitative shifts in students' mental models from pretest to posttest. Results indicated that…

  20. The Use of Comprehension Aids in a Hypermedia Environment: Investigating the Impact of Metacognitive Awareness and Epistemic Beliefs.

    ERIC Educational Resources Information Center

    Hartley, Kendall; Bendixen, Lisa D.

    A descriptive study analyzed learners' use of comprehensive aids such as objectives and the glossary in a hypermedia tutorial. College students (n=101) read a short hypermedia tutorial on the topic of E. coli. Relationships between the use of the comprehension aids and individual characteristics such as metacognitive awareness and epistemic…

  1. The Use of Comprehension Aids in a Hypermedia Environment: Investigating the Impact of Metacognitive Awareness and Epistemological Beliefs

    ERIC Educational Resources Information Center

    Hartley, Kendall; Bendixen, Lisa D.

    2003-01-01

    This is a descriptive study that analyzes learners' use of comprehension aids such as objectives, a glossary and links between pages in a hypermedia tutorial. Students read a short hypermedia tutorial on the topic of E. coli. Relationships between the use of the comprehension aids and individual characteristics such as metacognitive awareness and…

  2. Information Retrieval as Hypermedia: An Outline of InterBrowse.

    ERIC Educational Resources Information Center

    Kahn, Paul

    InterBrowse, a uniform interface information retrieval application for several different databases, is designed to be used in Intermedia, a hypermedia environment currently under development at Brown University's Institute for Research Information and Scholarship. This application arose out of the recognized need for an interface that can be used…

  3. Hypermedia Reading Strategies Employed by Advanced Learners of English

    ERIC Educational Resources Information Center

    Akyel, Ayse; Ercetin, Gulcan

    2009-01-01

    This study investigated the strategies used by advanced learners of English while reading a hypermedia document in order to determine whether they are essentially different from those reading strategies reported in the literature for printed texts. Moreover, the role of prior knowledge about the topic was explored in relation to strategy use. Data…

  4. Developing Modular and Adaptable Courseware Using TeachML.

    ERIC Educational Resources Information Center

    Wehner, Frank; Lorz, Alexander

    This paper presents the use of an XML grammar for two complementary projects--CHAMELEON (Cooperative Hypermedia Adaptive MultimEdia Learning Objects) and EIT (Enabling Informal Teamwork). Areas of applications are modular courseware documents and the collaborative authoring process of didactical units. A number of requirements for a suitable…

  5. ED-Media 94--World Conference on Educational Multimedia and Hypermedia (Vancouver, British Columbia, Canada, June 25-30, 1994). Panel Discussions.

    ERIC Educational Resources Information Center

    Boyle, Tom; And Others

    Six conference panel discussions on uses of technology in education are presented. The first panel, "The Use of Hypermedia in the Teaching and Learning of Programming" (Tom Boyle, Chair, and others) discusses achievements in hypermedia-based instruction, design needs, and experiences. The second panel, "Virtual Clayoquot Video…

  6. Hypertext, Hypermedia, and Metacognition: Research and Instructional Implications for Disabled Readers.

    ERIC Educational Resources Information Center

    Balajthy, Ernest

    1990-01-01

    The article examines the potential impact of computer-based text technologies, called hypermedia, on disabled readers. Discussed are hypertext, the hypercard, and implications of metacognitive research (such as author versus user control over text manipulations), instructional implications, and instructional text engineering. (DB)

  7. Efficient Authoring of SCORM Courseware Adapted to User Learning Style: The Case of ProPer SAT

    NASA Astrophysics Data System (ADS)

    Kazanidis, Ioannis; Satratzemi, Maya

    Online courses are the most popular way to deliver knowledge for distance learning. New researches attempt to personalize the educational process with the use of the Adaptive Educational Hypermedia Systems. Moreover, due to the significant amount of time, money and effort devoted to creating online courses, developers strive to incorporate standards, such as SCORM, for the reusability, interoperability and durability of the educational content. However, it is a difficult task for teachers without programming knowledge to design and author adaptive courses. This work presents ProPer SAT, an authoring tool implemented for quick and easy SCORM courseware construction which can also be adapted to specific user learning styles.

  8. ED-Media 94--World Conference on Educational Multimedia and Hypermedia (Vancouver, British Columbia, Canada, June 25-30, 1994). Short Papers.

    ERIC Educational Resources Information Center

    Abbanat, Rob; And Others

    The 49 short (one- or two-page) conference papers presented here document concern for the use of hypermedia and multimedia technology in education. Discussion includes the use of multimedia technology in various subject areas, programming languages, electronic books, intelligent tutoring systems, distance education, knowledge representation,…

  9. A Comparison of Books and Hypermedia for Knowledge-based Sports Coaching.

    ERIC Educational Resources Information Center

    Vickers, Joan N.; Gaines, Brian R.

    1988-01-01

    Summarizes and illustrates the knowledge-based approach to instructional material design. A series of sports coaching handbooks and hypermedia presentations of the same material are described and the different instantiations of the knowledge and training structures are compared. Figures show knowledge structures for badminton and the architecture…

  10. Schools Gear Up for "Hypermedia"--A Quantum Leap in Electronic Learning.

    ERIC Educational Resources Information Center

    Trotter, Andrew

    1989-01-01

    A new technological phenomenon known as "hypermedia" or "interactive multimedia" allows the learner to be in control and to access a variety of media with a computer. Advances in information storage technology have placed libraries of documents, sounds, and video and graphic images on laser discs. (MLF)

  11. ICCE/ICCAI 2000 Full & Short Papers (Multimedia and Hypermedia in Education).

    ERIC Educational Resources Information Center

    2000

    This document contains the full and short papers on multimedia and hypermedia in education from ICCE/ICCAI 2000 (International Conference on Computers in Education/International Conference on Computer-Assisted Instruction) covering the following topics: learner-centered navigation path planning in world Wide Web-based learning; the relation…

  12. The Relationships between Navigational Patterns and Informational Processing Styles of Hypermedia Users.

    ERIC Educational Resources Information Center

    Lee, Mi Jar; Harvey, Francis A.

    This study investigated the relationships between hypermedia users' information processing styles and navigational patterns. Three aspects of navigational patterns were investigated: navigational depth patterns that reveal how comprehensively users access; navigational path patterns that display what sequences users follow; and navigational method…

  13. Predictors of Foreign Language Reading Comprehension in a Hypermedia Reading Environment

    ERIC Educational Resources Information Center

    Akbulut, Yavuz

    2008-01-01

    This study investigated factors affecting second/foreign language (L2) reading comprehension in a hypermedia environment within the theoretical framework of dual coding and cognitive load theories, and interactive models of L2 reading. The independent variables were reading ability, topic interest, prior topical knowledge, and the number of times…

  14. Hypermedia Reading Materials: Undergraduate Perceptions and Features Affecting Their Reading Comprehension

    ERIC Educational Resources Information Center

    Hamdan, Nurul Adila; Mohamad, Maslawati; Shaharuddin, Shahizan

    2017-01-01

    Due to the potential of the Internet and blended learning environment, students, especially L2 learners, are often required to read references available online. A study was conducted to identify the perceptions of L2 learners comprising TESL undergraduates towards TESL-related hypermedia reading materials and the factors contributing to their…

  15. The object the metaphor the power and evergreen or the eighth way to make a hypermedia project fail

    NASA Technical Reports Server (NTRS)

    Warren, Bruce A.

    1990-01-01

    A patented software technique is described that is necessary and sufficient to keep hypermedia data bases current with the manufacturing technology. The technique proved its validity in four years of use in petrochemical plants. This technique is based on the following principles: (1) the data base must be object structured, i.e., all components must retain visible individuality; (2) the author must be seeing and experiencing the multimedia data objects as he creates; and (3) the hypermedia tools must possess power in the form of unlimited capacity.

  16. Measuring Cognitive and Metacognitive Regulatory Processes during Hypermedia Learning: Issues and Challenges

    ERIC Educational Resources Information Center

    Azevedo, Roger; Moos, Daniel C.; Johnson, Amy M.; Chauncey, Amber D.

    2010-01-01

    Self-regulated learning (SRL) with hypermedia environments involves a complex cycle of temporally unfolding cognitive and metacognitive processes that impact students' learning. We present several methodological issues related to treating SRL as an event and strengths and challenges of using online trace methodologies to detect, trace, model, and…

  17. Training University Faculty To Integrate Hypermedia into the Teacher Training Curriculum.

    ERIC Educational Resources Information Center

    Tucker, S. A.; And Others

    Funded under the Apple Model Program for the Integration of Computers in the Preparation of Educators, the University of South Alabama began a 3-year project in 1989 to train faculty in its College of Education to incorporate hypermedia into their curriculum. HyperCard was selected as a course presentation and development tool because of its…

  18. Hypermedia-Assisted Instruction and Second Language Learning: A Semantic-Network-Based Approach.

    ERIC Educational Resources Information Center

    Liu, Min

    This literature review examines a hypermedia learning environment from a semantic network basis and the application of such an environment to second language learning. (A semantic network is defined as a conceptual representation of knowledge in human memory). The discussion is organized under the following headings and subheadings: (1) Advantages…

  19. An Evaluation of Electronic Product Design Education Using Hypermedia-Resourced Learning Environments

    ERIC Educational Resources Information Center

    Page, Tom; Thorsteinsson, Gisli

    2006-01-01

    The work outlined here provides a comprehensive report and formative observations of the development and implementation of hypermedia resources for learning and teaching used in conjunction with a managed learning environment (MLE). These resources are used to enhance teaching and learning of an electronics module in product design at final year…

  20. Hypermedia without Programming: Automatic Generation of Presentation Documents for Case-based Instruction.

    ERIC Educational Resources Information Center

    Grissom, Scott; Koschmann, Tim

    The objective of this project was to develop a way of producing instructional materials such that once an acceptable design had been achieved, hypermedia documents could be easily generated with no additional programming or design effort. The project was undertaken to support a case-based instructional curriculum in medical education. Southern…

  1. The Impact of Hypermedia Instructional Materials on Study Self-Regulation in College Students.

    ERIC Educational Resources Information Center

    Nelms, Keith R.

    The metacognition "calibration of comprehension" research paradigm is used to investigate the question of whether the introduction of hypertext and hypermedia into college instruction impacts students' ability to regulate their own learning processes. Presentation technology (paper or computer) and content structure (linear or nonlinear) were…

  2. Hermeneutics, Accreting Receptions, Hypermedia: A Tool for Reference Versus a Tool for Instruction.

    ERIC Educational Resources Information Center

    Nissan, Ephraim; Rossler, Isaac; Weiss, Hillel

    1997-01-01

    Provides a select overview of hypertext and information retrieval tools that support traditional Jewish learning and discusses a project in instructional hypermedia that is applied to teaching, teacher training, and self-instruction in given Bible passages. Highlights include accretion of receptions, hermeneutics, literary appropriations, and…

  3. Personalization in an Interactive Learning Environment through a Virtual Character

    ERIC Educational Resources Information Center

    Reategui, E.; Boff, E.; Campbell, J. A.

    2008-01-01

    Traditional hypermedia applications present the same content and provide identical navigational support to all users. Adaptive Hypermedia Systems (AHS) make it possible to construct personalized presentations to each user, according to preferences and needs identified. We present in this paper an alternative approach to educational AHS where a…

  4. Learning with Hyperlinked Videos--Design Criteria and Efficient Strategies for Using Audiovisual Hypermedia

    ERIC Educational Resources Information Center

    Zahn, Carmen; Barquero, Beatriz; Schwan, Stephan

    2004-01-01

    In this article, we discuss the results of an experiment in which we studied two apparently conflicting classes of design principles for instructional hypervideos: (1) those principles derived from work on multimedia learning that emphasize spatio-temporal contiguity and (2) those originating from work on hypermedia learning that favour…

  5. ED-MEDIA/ED-TELECOM 98 World Conference on Educational Multimedia and Hypermedia & World Conference on Educational Telecommunications. Proceedings (10th, Freiburg, Germany, June 20-25, 1998).

    ERIC Educational Resources Information Center

    Ottmann, Thomas, Ed.; Tomek, Ivan, Ed.

    This collection presents papers pertaining to the wide area of educational multimedia/hypermedia and telecommunications. The conference serves as a forum for the dissemination of information on the research, development, and applications in all areas of multimedia/hypermedia and telecommunications in education across all disciplines and levels.…

  6. The Embodiment of Cases as Alternative Perspective in a Mathematics Hypermedia Learning Environment

    ERIC Educational Resources Information Center

    Valentine, Keri D.; Kopcha, Theodore J.

    2016-01-01

    This paper presents a design framework for cases as alternative perspectives (Jonassen in Learning to solve problems: a handbook for designing problem-solving learning environments, 2011a) in the context of K-12 mathematics. Using the design-based research strategy of conjecture mapping, the design of cases for a hypermedia site is described…

  7. Student-Authored Hypermedia in Veterinary Anatomy: Teaching and Learning Outcomes of Group Project Work.

    ERIC Educational Resources Information Center

    Garvin, Anthony; Carrington, Stephen

    1997-01-01

    Describes the Directed-Self Education program at the University of Bristol (England) for undergraduate small-group project work in veterinary science that was designed to support students in developing personal study and information technology skills. It also produced student-authored hypermedia tools which could be repurposed by staff as teaching…

  8. The Role of Anchored Instruction in the Design of a Hypermedia Science Museum Exhibit.

    ERIC Educational Resources Information Center

    Bell, Benjamin; And Others

    A hypermedia simulation, Sickle Cell Counselor, has been developed to anchor instruction for museum visitors using the task of advising couples about the decision to have children when there is a substantial genetic risk of sickle cell disease. A visitor can perform simulated laboratory tests and ask questions via interactive video. The anchored…

  9. Improvement of Self-regulated Learning in Mathematics through a Hypermedia Application: Differences based on Academic Performance and Previous Knowledge.

    PubMed

    Cueli, Marisol; Rodríguez, Celestino; Areces, Débora; García, Trinidad; González-Castro, Paloma

    2017-12-04

    Self-regulation on behalf of the student is crucial in learning Mathematics through hypermedia applications and is an even greater challenge in these IT environments. Two aims are formulated. First, to analyze the effectiveness of a hypermedia tool in improving perceived knowledge of self-regulatory strategies and the perceived usage of the planning, executing and assessment strategy on behalf of students with low, medium and high levels of academic performance. Second, to analyze the effectiveness of the hypermedia tool in improving perceived usage of the strategy for planning, monitoring and evaluating on behalf of students with a perceived knowledge (low, medium and high). Participants were 624 students (aged 10-13), classified into a treatment group (TG; 391) and a comparative group (CG; 233). They completed a questionnaire on perceived knowledge (Perceived Knowledge of Self-Regulatory Strategies) and another one on perceived usage of the strategy for planning, performing and evaluating (Inventory of Self-regulatory Learning Processes). Univariate covariance analyses (ANCOVAs) and Student-t tests were used. ANCOVA results were not statistically significant. However, the linear contrast indicated a significant improvement in perceived knowledge of strategies among the TG with low, medium and high academic performance (p ≤ .001). Results are discussed in the light of past and future research.

  10. Utilizing a Rapid Prototyping Approach in the Building of a Hypermedia-Based Reference Station.

    ERIC Educational Resources Information Center

    Sell, Dan

    This paper discusses the building of a hypermedia-based reference station at the Wright Laboratory Technical Library, Wright-Patterson Air Force Base, Ohio. Following this, the paper focuses on an electronic user survey from which data is collected and analysis is made. The survey data is used in a rapid prototyping approach, which is defined as…

  11. Assessing Team-Based Instructional Design Problem Solutions of Hierarchical Versus Heterarchical Web-Based Hypermedia Cases

    ERIC Educational Resources Information Center

    Dabbagh, Nada; Denisar, Katrina

    2005-01-01

    For this study, we examined the cogency, comprehensiveness, and viability of team-based problem solutions of a Web-based hypermedia case designed to promote student understanding of the practice of instructional design. Participants were 14 students enrolled in a graduate course on advanced instructional design. The case was presented to students…

  12. Incremental Validity of Thinking Styles in Predicting Academic Achievements: An Experimental Study in Hypermedia Learning Environments

    ERIC Educational Resources Information Center

    Fan, Weiqiao; Zhang, Li-Fang; Watkins, David

    2010-01-01

    The study examined the incremental validity of thinking styles in predicting academic achievement after controlling for personality and achievement motivation in the hypermedia-based learning environment. Seventy-two Chinese college students from Shanghai, the People's Republic of China, took part in this instructional experiment. The…

  13. Student Assistant for Learning from Text (SALT): a hypermedia reading aid.

    PubMed

    MacArthur, C A; Haynes, J B

    1995-03-01

    Student Assistant for Learning from Text (SALT) is a software system for developing hypermedia versions of textbooks designed to help students with learning disabilities and other low-achieving students to compensate for their reading difficulties. In the present study, 10 students with learning disabilities (3 young women and 7 young men ages 15 to 17) in Grades 9 and 10 read passages from a science textbook using a basic computer version and an enhanced computer version. The basic version included the components found in the printed textbook (text, graphics, outline, and questions) and a notebook. The enhanced version added speech synthesis, an on-line glossary, links between questions and text, highlighting of main ideas, and supplementary explanations that summarized important ideas. Students received significantly higher comprehension scores using the enhanced version. Furthermore, students preferred the enhanced version and thought it helped them learn the material better.

  14. A Hypermedia Lesson about 1875-1885 Costume: Cognitive Style, Perceptual Modes, Anxiety, Attitude, and Achievement.

    ERIC Educational Resources Information Center

    Frey, Diane; Simonson, Michael

    The purpose of this study was to obtain students' cognitive style profiles and obtain a record of their use of three information modes during the hypermedia lesson, "A Look Backward: An Encounter with Late Victorian Fashion." The study examined relationships among: (1) nine dimensions of cognitive style, as measured by the National…

  15. A framework for the design of a voice-activated, intelligent, and hypermedia-based aircraft maintenance manual

    NASA Astrophysics Data System (ADS)

    Patankar, Manoj Shashikant

    Federal Aviation Regulations require Aviation Maintenance Technicians (AMTs) to refer to approved maintenance manuals when performing maintenance on airworthy aircraft. Because these manuals are paper-based, larger the size of the aircraft, more cumbersome are the manuals. Federal Aviation Administration (FAA) recognized the difficulties associated with the use of large manuals and conducted studies on the use of electronic media as an alternative to the traditional paper format. However, these techniques do not employ any artificial intelligence technologies and the user interface is limited to either a keyboard or a stylus pen. The primary emphasis of this research was to design a generic framework that would allow future development of voice-activated, intelligent, and hypermedia-based aircraft maintenance manuals. A prototype (VIHAMS-Voice-activated, Intelligent, and Hypermedia-based Aircraft Maintenance System) was developed, as a secondary emphasis, using the design and development techniques that evolved from this research. An evolutionary software design approach was used to design the proposed framework and the structured rapid prototyping technique was used to produce the VIHAMS prototype. VoiceAssist by Creative Labs was used to provide the voice interface so that the users (AMTs) could keep their hands free to work on the aircraft while maintaining complete control over the computer through discrete voice commands. KnowledgePro for Windows sp{TM}, an expert system shell, provided "intelligence" to the prototype. As a result of this intelligence, the system provided expert guidance to the user. The core information contained in conventional manuals was available in a hypermedia format. The prototype's operating hardware included a notebook computer with a fully functional audio system. An external microphone and the built-in speaker served as the input and output devices (along with the color monitor), respectively. Federal Aviation Administration

  16. The ABC's of Screen Design: What Teachers Should Know To Teach Students To Author in Hypermedia.

    ERIC Educational Resources Information Center

    Dana, Ann S.; Handler, Marianne G.

    The alphabet can be used as a framework for identifying key issues, ideas, and factors that teachers and students need to consider in developing hypermedia projects. Rather than in alphabetical order, the terms are introduced as they apply to the discussion on the teaching of multimedia skills. The following terms and concepts are highlighted:…

  17. The Ontologies of Complexity and Learning about Complex Systems

    ERIC Educational Resources Information Center

    Jacobson, Michael J.; Kapur, Manu; So, Hyo-Jeong; Lee, June

    2011-01-01

    This paper discusses a study of students learning core conceptual perspectives from recent scientific research on complexity using a hypermedia learning environment in which different types of scaffolding were provided. Three comparison groups used a hypermedia system with agent-based models and scaffolds for problem-based learning activities that…

  18. EdMedia 2012: World Conference on Educational Multimedia, Hypermedia and Telecommunications. Proceedings (Denver, Colorado, June 26-29, 2012)

    ERIC Educational Resources Information Center

    Amiel, Tel, Ed.; Wilson, Brent, Ed.

    2012-01-01

    The Association for the Advancement of Computing in Education (AACE) is an international, non-profit educational organization. The Association's purpose is to advance the knowledge, theory, and quality of teaching and learning at all levels with information technology. "EdMedia 2012: World Conference on Educational Multimedia, Hypermedia and…

  19. Development and Evaluation of Internet-Based Hypermedia Chemistry Tutorials

    NASA Astrophysics Data System (ADS)

    Tissue, Brian M.; Earp, Ronald L.; Yip, Ching-Wan; Anderson, Mark R.

    1996-05-01

    This progress report describes the development and student use of World-Wide-Web-based prelaboratory exercises in senior-level Instrumental Analysis during the 1995 Fall semester. The laboratory preparation exercises contained hypermedia tutorials and multiple-choice questions that were intended to familiarize the students with the experiments and instrumentation before their laboratory session. The overall goal of our work is to explore ways in which computer and network technology can be applied in education to improve the cost-effectiveness and efficacy of teaching. The course material can be accessed at http://www.chem.vt.edu/chem-ed/4114/Fall1995.html. The students were instructed to read their experimental procedure and to do the relevant laboratory preparation exercise. The individual tutorial documents were primarily text that provided basic theoretical and experimental descriptions of analytical and instrumental methods. The documents included hyperlinks to basic concepts, simple schematics, and color graphics of experimental set-ups or instrumentation. We chose the World-Wide Web (WWW) as the delivery platform for this project because of the ease of developing, distributing, and modifying hypermedia material in a client-server system. The disadvantage of the WWW is that network bandwidth limits the size and sophistication of the hypermedia material. To minimize internet transfer time, the individual documents were kept short and usually contained no more than 3 or 4 inline images. After reading the tutorial the students answered several multiple-choice questions. The figure shows one example of a multiple-choice question and the response page. Clicking on the "Submit answer" button calls a *.cgi file, which contains instructions in the PERL interpretive language, that generates the response page and saves the date, time, and student's answer to a file on the server. Usage and student perception of the on-line material was evaluated from server logs and

  20. Learning Mediated by an Educational Hypermedia

    NASA Astrophysics Data System (ADS)

    Fagundes, Adriano Luiz; da Silva, Tatiana; Barroso, Marta Feijó

    2015-12-01

    The phases of the Moon is a learning subject composed of smaller units here elaborated by adopting the theory of cognitive load, including aspects related to visualization in science education and taking into account learning difficulties documented in the research literature on science/astronomy teaching as theoretical guiding. The complete research process involved 77 students attending an undergraduate physics course and included data collection instruments to investigate technical aspects of the material, quality of contents and learning. This work focused on learning mediated by a hypermedia digital resource. The instruments used at this stage were pre-testing and learning evaluation allowing a qualitative and quantitative assessment. The questions pointed to the knowledge of the Moon as a body without its own light, to representations of schematic diagrams with sequences of lunar phases and the possibility of observing the Sun and the Moon according to the time of the day, an explanation and a representation of the dynamics of synchronous rotation motion of the Moon. The result provided an overall average increase of 33% in learning. We point out the features of the material that may have contributed to a highest quality as a learning tool.

  1. Use of a Case-Based Hypermedia Resource in an Early Literacy Coaching Intervention with Pre-Kindergarten Teachers

    ERIC Educational Resources Information Center

    Powell, Douglas R.; Diamond, Karen E.; Koehler, Matthew J.

    2010-01-01

    Use of a case-based hypermedia resource (HR) was examined in a Web-based early literacy coaching intervention with pre-kindergarten teachers of at-risk children. Web usage logs, written records of coach feedback to teachers on their instruction, and a teacher questionnaire were the primary data sources. Visits to the HR content pages were unevenly…

  2. Individualized Special Education with Cognitive Skill Assessment.

    ERIC Educational Resources Information Center

    Kurhila, Jaakko; Laine, Tei

    2000-01-01

    Describes AHMED (Adaptive and Assistive Hypermedia in Education), a computer learning environment which supports the evaluation of disabled children's cognitive skills in addition to supporting openness in learning materials and adaptivity in learning events. Discusses cognitive modeling and compares it to previous intelligent tutoring systems.…

  3. The Development of Physics Learning Instrument Based on Hypermedia and Its Influence on the Student Problem Solving Skill

    ERIC Educational Resources Information Center

    Amin, Bunga Dara; Mahmud, Alimuddin; Muris

    2016-01-01

    This research aims to produce a learning instrument based on hypermedia which is valid, interesting, practical, and effective as well as to know its influence on the problem based skill of students Mathematical and Science Faculty, Makassar State University. This research is a research and development at (R&D) type. The development procedure…

  4. ED-MEDIA 2001 World Conference on Educational Multimedia, Hypermedia & Telecommunications. Proceedings (13th, Tampere, Finland, June 25-30, 2001).

    ERIC Educational Resources Information Center

    Montgomerie, Craig, Ed.; Viteli, Jarmo, Ed.

    This 13th annual ED-MEDIA conference serves as a multidisciplinary forum for the discussion of the latest research, developments, and applications of multimedia, hypermedia, and telecommunications for all levels of education. This document contains papers from attendees representing more than 60 countries, with keynote speakers representing both…

  5. Exploring Relations among College Students' Prior Knowledge, Implicit Theories of Intelligence, and Self-Regulated Learning in a Hypermedia Environment

    ERIC Educational Resources Information Center

    Greene, Jeffrey Alan; Costa, Lara-Jeane; Robertson, Jane; Pan, Yi; Deekens, Victor M.

    2010-01-01

    Researchers and educators continue to explore how to assist students in the acquisition of conceptual understanding of complex science topics. While hypermedia learning environments (HLEs) afford unique opportunities to display multiple representations of these often abstract topics, students who do not engage in self-regulated learning (SRL) with…

  6. Adaptation in Living Systems

    NASA Astrophysics Data System (ADS)

    Tu, Yuhai; Rappel, Wouter-Jan

    2018-03-01

    Adaptation refers to the biological phenomenon where living systems change their internal states in response to changes in their environments in order to maintain certain key functions critical for their survival and fitness. Adaptation is one of the most ubiquitous and arguably one of the most fundamental properties of living systems. It occurs throughout all biological scales, from adaptation of populations of species over evolutionary time to adaptation of a single cell to different environmental stresses during its life span. In this article, we review some of the recent progress made in understanding molecular mechanisms of cellular-level adaptation. We take the minimalist (or the physicist) approach and study the simplest systems that exhibit generic adaptive behaviors, namely chemotaxis in bacterium cells (Escherichia coli) and eukaryotic cells (Dictyostelium). We focus on understanding the basic biochemical interaction networks that are responsible for adaptation dynamics. By combining theoretical modeling with quantitative experimentation, we demonstrate universal features in adaptation as well as important differences in different cellular systems. Future work in extending the modeling framework to study adaptation in more complex systems such as sensory neurons is also discussed.

  7. Dynamic Learning Style Prediction Method Based on a Pattern Recognition Technique

    ERIC Educational Resources Information Center

    Yang, Juan; Huang, Zhi Xing; Gao, Yue Xiang; Liu, Hong Tao

    2014-01-01

    During the past decade, personalized e-learning systems and adaptive educational hypermedia systems have attracted much attention from researchers in the fields of computer science Aand education. The integration of learning styles into an intelligent system is a possible solution to the problems of "learning deviation" and…

  8. Recent Contributions to a Generic Architecture Design that Supports Learning Objects Interoperability

    ERIC Educational Resources Information Center

    Botsios, Sotirios; Georgiou, Dimitrios A.

    2009-01-01

    Adaptation and personalization services in e-learning environments are considered the turning point of recent research efforts, as the "one-size-fits-all" approach has some important drawbacks, from the educational point of view. Adaptive Educational Hypermedia Systems in World Wide Web became a very active research field and the need of…

  9. Identification of Learning Styles Online by Observing Learners Browsing Behaviour through a Neural Network

    ERIC Educational Resources Information Center

    Lo, Jia-Jiunn; Shu, Pai-Chuan

    2005-01-01

    Identification of individual learning style is important when developing adaptive educational hypermedia systems. Current systems ask learners to complete questionnaires to identify their learning styles, which might not be appropriate in some contexts. The goal of this research is to identify the learner's learning style by simply observing…

  10. Adaptive control of periodic systems

    NASA Astrophysics Data System (ADS)

    Tian, Zhiling

    2009-12-01

    Adaptive control is needed to cope with parametric uncertainty in dynamical systems. The adaptive control of LTI systems in both discrete and continuous time has been studied for four decades and the results are currently used widely in many different fields. In recent years, interest has shifted to the adaptive control of time-varying systems. It is known that the adaptive control of arbitrarily rapidly time-varying systems is in general intractable, but systems with periodically time-varying parameters (LTP systems) which have much more structure, are amenable to mathematical analysis. Further, there is also a need for such control in practical problems which have arisen in industry during the past twenty years. This thesis is the first attempt to deal with the adaptive control of LTP systems. Adaptive Control involves estimation of unknown parameters, adjusting the control parameters based on the estimates, and demonstrating that the overall system is stable. System theoretic properties such as stability, controllability, and observability play an important role both in formulating of the problems, as well as in generating solutions for them. For LTI systems, these properties have been studied since 1960s, and algebraic conditions that have to be satisfied to assure these properties are now well established. In the case of LTP systems, these properties can be expressed only in terms of transition matrices that are much more involved than those for LTI systems. Since adaptive control problems can be formulated only when these properties are well understood, it is not surprising that systematic efforts have not been made thus far for formulating and solving adaptive control problems that arise in LTP systems. Even in the case of LTI systems, it is well recognized that problems related to adaptive discrete-time system are not as difficult as those that arise in the continuous-time systems. This is amply evident in the solutions that were derived in the 1980s and

  11. Media Selection for the Development of a Hypermedia/Multimedia Instructional Model for the Navy’s 76mm Gun

    DTIC Science & Technology

    1993-09-01

    placed on the timeline when called. The timeline editor is also used when creating a hypertext/hypermedia document. a FrameMaker FrameMaker is a...Framemaker’s multi-platform capability permits document sharing and allows for easy importing of text and graphics from other application software. Framemaker ...Technology Corporation, FrameMaker Reference, September 1990. Glaser, R., "Education and Thinking: The Role of Knowledge", American Psychologist, Vol. 39, No

  12. Comparison of a brain-based adaptive system and a manual adaptable system for invoking automation.

    PubMed

    Bailey, Nathan R; Scerbo, Mark W; Freeman, Frederick G; Mikulka, Peter J; Scott, Lorissa A

    2006-01-01

    Two experiments are presented examining adaptive and adaptable methods for invoking automation. Empirical investigations of adaptive automation have focused on methods used to invoke automation or on automation-related performance implications. However, no research has addressed whether performance benefits associated with brain-based systems exceed those in which users have control over task allocations. Participants performed monitoring and resource management tasks as well as a tracking task that shifted between automatic and manual modes. In the first experiment, participants worked with an adaptive system that used their electroencephalographic signals to switch the tracking task between automatic and manual modes. Participants were also divided between high- and low-reliability conditions for the system-monitoring task as well as high- and low-complacency potential. For the second experiment, participants operated an adaptable system that gave them manual control over task allocations. Results indicated increased situation awareness (SA) of gauge instrument settings for individuals high in complacency potential using the adaptive system. In addition, participants who had control over automation performed more poorly on the resource management task and reported higher levels of workload. A comparison between systems also revealed enhanced SA of gauge instrument settings and decreased workload in the adaptive condition. The present results suggest that brain-based adaptive automation systems may enhance perceptual level SA while reducing mental workload relative to systems requiring user-initiated control. Potential applications include automated systems for which operator monitoring performance and high-workload conditions are of concern.

  13. The Impact of Control Belief and Learning Disorientation on Cognitive Load: The Mediating Effect of Academic Emotions in Two Types of Hypermedia Learning Environments

    ERIC Educational Resources Information Center

    Sunawan; Xiong, Junmei

    2017-01-01

    The present study tested the influence of control belief, learning disorientation, and academic emotions on cognitive load in two types of concept-map structures within hypermedia learning environment. Four hundred and eighty-five students were randomly assigned to two groups: 245 students in the hierarchical group and 240 students in the…

  14. Turbine system and adapter

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hogberg, Nicholas Alvin; Garcia-Crespo, Andres Jose

    A turbine system and adapter are disclosed. The adapter includes a turbine attachment portion having a first geometry arranged to receive a corresponding geometry of a wheelpost of a turbine rotor, and a bucket attachment portion having a second geometry arranged to receive a corresponding geometry of a root portion of a non-metallic turbine bucket. Another adapter includes a turbine attachment portion arranged to receive a plurality of wheelposts of a turbine rotor, and a bucket attachment portion arranged to receive a plurality of non-metallic turbine buckets having single dovetail configuration root portions. The turbine system includes a turbine rotormore » wheel configured to receive metal buckets, at least one adapter secured to at least one wheelpost on the turbine rotor wheel, and at least one non-metallic bucket secured to the at least one adapter.« less

  15. Hypermedia or Hyperchaos: Using HyperCard to Teach Medical Decision Making

    PubMed Central

    Smith, W.R.; Hahn, J.S.

    1989-01-01

    HyperCard presents an uncoventional instructional environment for educators and students, in that it is nonlinear, nonsequential, and it provides innumerable choices of learning paths to learners. The danger of this environment is that it may frustrate learners whose cognitive and learning styles do not match this environment. Leaners who prefer guided learning rather than independent exploration may become distracted or disoriented by this environment, lost in “hyperspace.” In the context of medical education, these ill-matched styles may produce some physicians who have not mastered skills essential to the practice of medicine. The authors have sought to develop a HyperCard learning environment consisting of related programs that teach medical decision making. The environment allows total learner control until the learner demonstrates a need for guidance in order to achieve the essential objectives of the program. A discussion follows of the implications of hypermedia for instructional design and medical education.

  16. Examining Middle School Science Student Self-Regulated Learning in a Hypermedia Learning Environment through Microanalysis

    NASA Astrophysics Data System (ADS)

    Mandell, Brian E.

    The purpose of the present embedded mixed method study was to examine the self-regulatory processes used by high, average, and low achieving seventh grade students as they learned about a complex science topic from a hypermedia learning environment. Thirty participants were sampled. Participants were administered a number of measures to assess their achievement and self-efficacy. In addition, a microanalytic methodology, grounded in Zimmerman's cyclical model of self-regulated learning, was used to assess student self-regulated learning. It was hypothesized that there would be modest positive correlations between Zimmerman's three phases of self-regulated learning, that high achieving science students would deploy more self-regulatory subprocesses than average and low achieving science students, that high achieving science students would have higher self-efficacy beliefs to engage in self-regulated learning than average and low achieving science students, and that low achieving science students would over-estimate their self-efficacy for performance beliefs, average achieving science students would slightly overestimate their self-efficacy for performance beliefs, and high achieving science students would under-estimate their self-efficacy for performance beliefs. All hypotheses were supported except for the high achieving science students who under-estimated their self-efficacy for performance beliefs on the Declarative Knowledge Measure and slightly overestimated their self-efficacy for performance beliefs on the Conceptual Knowledge Measure. Finally, all measures of self-regulated learning were combined and entered into a regression formula to predict the students' scores on the two science tests, and it was revealed that the combined measure predicted 91% of the variance on the Declarative Knowledge Measure and 92% of the variance on the Conceptual Knowledge Measure. This study adds hypermedia learning environments to the contexts that the microanalytic

  17. Designing Interactive Learning Systems.

    ERIC Educational Resources Information Center

    Barker, Philip

    1990-01-01

    Describes multimedia, computer-based interactive learning systems that support various forms of individualized study. Highlights include design models; user interfaces; design guidelines; media utilization paradigms, including hypermedia and learner-controlled models; metaphors and myths; authoring tools; optical media; workstations; four case…

  18. Towards Methodologies for Building Knowledge-Based Instructional Systems.

    ERIC Educational Resources Information Center

    Duchastel, Philippe

    1992-01-01

    Examines the processes involved in building instructional systems that are based on artificial intelligence and hypermedia technologies. Traditional instructional systems design methodology is discussed; design issues including system architecture and learning strategies are addressed; and a new methodology for building knowledge-based…

  19. Adaptation in CRISPR-Cas Systems.

    PubMed

    Sternberg, Samuel H; Richter, Hagen; Charpentier, Emmanuelle; Qimron, Udi

    2016-03-17

    Clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) proteins constitute an adaptive immune system in prokaryotes. The system preserves memories of prior infections by integrating short segments of foreign DNA, termed spacers, into the CRISPR array in a process termed adaptation. During the past 3 years, significant progress has been made on the genetic requirements and molecular mechanisms of adaptation. Here we review these recent advances, with a focus on the experimental approaches that have been developed, the insights they generated, and a proposed mechanism for self- versus non-self-discrimination during the process of spacer selection. We further describe the regulation of adaptation and the protein players involved in this fascinating process that allows bacteria and archaea to harbor adaptive immunity. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Complex adaptive systems: concept analysis.

    PubMed

    Holden, Lela M

    2005-12-01

    The aim of this paper is to explicate the concept of complex adaptive systems through an analysis that provides a description, antecedents, consequences, and a model case from the nursing and health care literature. Life is more than atoms and molecules--it is patterns of organization. Complexity science is the latest generation of systems thinking that investigates patterns and has emerged from the exploration of the subatomic world and quantum physics. A key component of complexity science is the concept of complex adaptive systems, and active research is found in many disciplines--from biology to economics to health care. However, the research and literature related to these appealing topics have generated confusion. A thorough explication of complex adaptive systems is needed. A modified application of the methods recommended by Walker and Avant for concept analysis was used. A complex adaptive system is a collection of individual agents with freedom to act in ways that are not always totally predictable and whose actions are interconnected. Examples include a colony of termites, the financial market, and a surgical team. It is often referred to as chaos theory, but the two are not the same. Chaos theory is actually a subset of complexity science. Complexity science offers a powerful new approach--beyond merely looking at clinical processes and the skills of healthcare professionals. The use of complex adaptive systems as a framework is increasing for a wide range of scientific applications, including nursing and healthcare management research. When nursing and other healthcare managers focus on increasing connections, diversity, and interactions they increase information flow and promote creative adaptation referred to as self-organization. Complexity science builds on the rich tradition in nursing that views patients and nursing care from a systems perspective.

  1. ELM-ART--An Interactive and Intelligent Web-Based Electronic Textbook

    ERIC Educational Resources Information Center

    Weber, Gerhard; Brusilovsky, Peter

    2016-01-01

    This paper present provides a broader view on ELM-ART, one of the first Web-based Intelligent Educational systems that offered a creative combination of two different paradigms--Intelligent Tutoring and Adaptive Hypermedia technologies. The unique dual nature of ELM-ART contributed to its long life and research impact and was a result of…

  2. The effects of field dependent/independent style awareness on learning strategies and outcomes in an instructional hypermedia module

    NASA Astrophysics Data System (ADS)

    Fyle, Clifford Omodele

    The purpose of this study was to examine whether field-dependent/independent style awareness affects learning outcomes and learning strategies used in a hypermedia instructional module. Field-dependent/independent style was measured using the Global Embedded Figures Test. Style awareness meant that students were provided with information and explanations about their individual cognitive styles and the learning strategies that accommodate those styles. The study entailed examining students' achievement in a multiple-choice test and performance in a design task, and also their navigation patterns as they studied a science-oriented Webquest. The sample consisted of 149 eighth-grade students in 10 sections of a science class taught by two teachers in a public middle school. A two-group posttest-only design on one factor (style awareness) was used. Sixty-eight students in five sections of the class were assigned to the treatment group (field dependent/independent style awareness) while the other 81 students in five sections were assigned to the control group (no field dependent/independent style awareness). The study took place over a period of 6 days. On the first day, students in the treatment group were first tested and debriefed on their individual styles. Next, all students in both the treatment and control groups studied the hypermedia instructional module (Webquest) over a period of two days. On the fourth and fifth days students worked on the performance tasks, and on the sixth day students took the multiple-choice test and students in the control group were tested and debriefed on their individual styles. The findings indicate that style awareness significantly influenced the learning strategies of field-dependent students as they studied and carried out learning tasks in the Webquest. Field-dependent students with style awareness used hypertext links and navigated the menu sequentially a greater number of times than their counterparts with no style awareness

  3. NEEDS - Information Adaptive System

    NASA Technical Reports Server (NTRS)

    Kelly, W. L.; Benz, H. F.; Meredith, B. D.

    1980-01-01

    The Information Adaptive System (IAS) is an element of the NASA End-to-End Data System (NEEDS) Phase II and is focused toward onboard image processing. The IAS is a data preprocessing system which is closely coupled to the sensor system. Some of the functions planned for the IAS include sensor response nonuniformity correction, geometric correction, data set selection, data formatting, packetization, and adaptive system control. The inclusion of these sensor data preprocessing functions onboard the spacecraft will significantly improve the extraction of information from the sensor data in a timely and cost effective manner, and provide the opportunity to design sensor systems which can be reconfigured in near real-time for optimum performance. The purpose of this paper is to present the preliminary design of the IAS and the plans for its development.

  4. An integrated knowledge system for wind tunnel testing - Project Engineers' Intelligent Assistant

    NASA Technical Reports Server (NTRS)

    Lo, Ching F.; Shi, George Z.; Hoyt, W. A.; Steinle, Frank W., Jr.

    1993-01-01

    The Project Engineers' Intelligent Assistant (PEIA) is an integrated knowledge system developed using artificial intelligence technology, including hypertext, expert systems, and dynamic user interfaces. This system integrates documents, engineering codes, databases, and knowledge from domain experts into an enriched hypermedia environment and was designed to assist project engineers in planning and conducting wind tunnel tests. PEIA is a modular system which consists of an intelligent user-interface, seven modules and an integrated tool facility. Hypermedia technology is discussed and the seven PEIA modules are described. System maintenance and updating is very easy due to the modular structure and the integrated tool facility provides user access to commercial software shells for documentation, reporting, or database updating. PEIA is expected to provide project engineers with technical information, increase efficiency and productivity, and provide a realistic tool for personnel training.

  5. Quantitative adaptation analytics for assessing dynamic systems of systems: LDRD Final Report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gauthier, John H.; Miner, Nadine E.; Wilson, Michael L.

    2015-01-01

    Our society is increasingly reliant on systems and interoperating collections of systems, known as systems of systems (SoS). These SoS are often subject to changing missions (e.g., nation- building, arms-control treaties), threats (e.g., asymmetric warfare, terrorism), natural environments (e.g., climate, weather, natural disasters) and budgets. How well can SoS adapt to these types of dynamic conditions? This report details the results of a three year Laboratory Directed Research and Development (LDRD) project aimed at developing metrics and methodologies for quantifying the adaptability of systems and SoS. Work products include: derivation of a set of adaptability metrics, a method for combiningmore » the metrics into a system of systems adaptability index (SoSAI) used to compare adaptability of SoS designs, development of a prototype dynamic SoS (proto-dSoS) simulation environment which provides the ability to investigate the validity of the adaptability metric set, and two test cases that evaluate the usefulness of a subset of the adaptability metrics and SoSAI for distinguishing good from poor adaptability in a SoS. Intellectual property results include three patents pending: A Method For Quantifying Relative System Adaptability, Method for Evaluating System Performance, and A Method for Determining Systems Re-Tasking.« less

  6. Adaptive management of rangeland systems

    USGS Publications Warehouse

    Allen, Craig R.; Angeler, David G.; Fontaine, Joseph J.; Garmestani, Ahjond S.; Hart, Noelle M.; Pope, Kevin L.; Twidwell, Dirac

    2017-01-01

    Adaptive management is an approach to natural resource management that uses structured learning to reduce uncertainties for the improvement of management over time. The origins of adaptive management are linked to ideas of resilience theory and complex systems. Rangeland management is particularly well suited for the application of adaptive management, having sufficient controllability and reducible uncertainties. Adaptive management applies the tools of structured decision making and requires monitoring, evaluation, and adjustment of management. Adaptive governance, involving sharing of power and knowledge among relevant stakeholders, is often required to address conflict situations. Natural resource laws and regulations can present a barrier to adaptive management when requirements for legal certainty are met with environmental uncertainty. However, adaptive management is possible, as illustrated by two cases presented in this chapter. Despite challenges and limitations, when applied appropriately adaptive management leads to improved management through structured learning, and rangeland management is an area in which adaptive management shows promise and should be further explored.

  7. Recommendation System for Adaptive Learning.

    PubMed

    Chen, Yunxiao; Li, Xiaoou; Liu, Jingchen; Ying, Zhiliang

    2018-01-01

    An adaptive learning system aims at providing instruction tailored to the current status of a learner, differing from the traditional classroom experience. The latest advances in technology make adaptive learning possible, which has the potential to provide students with high-quality learning benefit at a low cost. A key component of an adaptive learning system is a recommendation system, which recommends the next material (video lectures, practices, and so on, on different skills) to the learner, based on the psychometric assessment results and possibly other individual characteristics. An important question then follows: How should recommendations be made? To answer this question, a mathematical framework is proposed that characterizes the recommendation process as a Markov decision problem, for which decisions are made based on the current knowledge of the learner and that of the learning materials. In particular, two plain vanilla systems are introduced, for which the optimal recommendation at each stage can be obtained analytically.

  8. Design Specifications for Adaptive Real-Time Systems

    DTIC Science & Technology

    1991-12-01

    TICfl \\ E CT E Design Specifications for JAN’\\ 1992 Adaptive Real - Time Systems fl Randall W. Lichota U, Alice H. Muntz - December 1991 \\ \\\\/ 0 / r...268-2056 Technical Report CMU/SEI-91-TR-20 ESD-91-TR-20 December 1991 Design Specifications for Adaptive Real - Time Systems Randall W. Lichota Hughes...Design Specifications for Adaptive Real - Time Systems Abstract: The design specification method described in this report treats a software

  9. Complex Adaptive Systems: The Theater Air Control System in Desert Storm

    DTIC Science & Technology

    2014-05-22

    insight into leverage points of effective and ineffective adaptation of the TACS. Successful adaptation indicates that increased variety or diversity of...encourages innovation and diversity of ideas. 15. SUBJECT TERMS Theater Air Control System, TACS, Complex Adaptive Systems, Adaptation, Desert Storm...increased variety or diversity of agents and purposeful behaviors are beneficial to overcoming complexity. Leaders play a key role in creating an

  10. Adaptive voting computer system

    NASA Technical Reports Server (NTRS)

    Koczela, L. J.; Wilgus, D. S. (Inventor)

    1974-01-01

    A computer system is reported that uses adaptive voting to tolerate failures and operates in a fail-operational, fail-safe manner. Each of four computers is individually connected to one of four external input/output (I/O) busses which interface with external subsystems. Each computer is connected to receive input data and commands from the other three computers and to furnish output data commands to the other three computers. An adaptive control apparatus including a voter-comparator-switch (VCS) is provided for each computer to receive signals from each of the computers and permits adaptive voting among the computers to permit the fail-operational, fail-safe operation.

  11. Framework for measuring adaptive knowledge-rich systems performance.

    PubMed

    Bushko, Renata G

    2005-01-01

    The universe is non repeatable in nature--most of events cannot be prestated and do not repeat themselves. The only way to create systems that are truly useful is to make them adaptive (able to reason by analogy and learn) and rich in knowledge (including common sense knowledge). Adaptive and knowledge-rich health management could get us closer to errorless health care where small incremental adjustments happen all the time preventing occurrence of an error. In the era of adaptive systems we need to have a way to evaluate their performance. Are they truly adaptive? How adaptive are they? Are they accurate enough? Are they fast enough? Are they cost effective? This chapter presents general framework for measuring adaptive knowledge-rich systems' performance and includes among others definitions of adaptiveness factor, britt (a unit of brittleness) and uso-quant (unit of usefulness of a piece of knowledge). Measuring adaptive knowledge-rich systems performance is one of the most important research areas that can have a big pay-off in healthcare now and in the future.

  12. An adaptive tracking observer for failure-detection systems

    NASA Technical Reports Server (NTRS)

    Sidar, M.

    1982-01-01

    The design problem of adaptive observers applied to linear, constant and variable parameters, multi-input, multi-output systems, is considered. It is shown that, in order to keep the observer's (or Kalman filter) false-alarm rate (FAR) under a certain specified value, it is necessary to have an acceptable proper matching between the observer (or KF) model and the system parameters. An adaptive observer algorithm is introduced in order to maintain desired system-observer model matching, despite initial mismatching and/or system parameter variations. Only a properly designed adaptive observer is able to detect abrupt changes in the system (actuator, sensor failures, etc.) with adequate reliability and FAR. Conditions for convergence for the adaptive process were obtained, leading to a simple adaptive law (algorithm) with the possibility of an a priori choice of fixed adaptive gains. Simulation results show good tracking performance with small observer output errors and accurate and fast parameter identification, in both deterministic and stochastic cases.

  13. Operator adaptation to changes in system reliability under adaptable automation.

    PubMed

    Chavaillaz, Alain; Sauer, Juergen

    2017-09-01

    This experiment examined how operators coped with a change in system reliability between training and testing. Forty participants were trained for 3 h on a complex process control simulation modelling six levels of automation (LOA). In training, participants either experienced a high- (100%) or low-reliability system (50%). The impact of training experience on operator behaviour was examined during a 2.5 h testing session, in which participants either experienced a high- (100%) or low-reliability system (60%). The results showed that most operators did not often switch between LOA. Most chose an LOA that relieved them of most tasks but maintained their decision authority. Training experience did not have a strong impact on the outcome measures (e.g. performance, complacency). Low system reliability led to decreased performance and self-confidence. Furthermore, complacency was observed under high system reliability. Overall, the findings suggest benefits of adaptable automation because it accommodates different operator preferences for LOA. Practitioner Summary: The present research shows that operators can adapt to changes in system reliability between training and testing sessions. Furthermore, it provides evidence that each operator has his/her preferred automation level. Since this preference varies strongly between operators, adaptable automation seems to be suitable to accommodate these large differences.

  14. [Health: an adaptive complex system].

    PubMed

    Toro-Palacio, Luis Fernando; Ochoa-Jaramillo, Francisco Luis

    2012-02-01

    This article points out the enormous gap that exists between complex thinking of an intellectual nature currently present in our environment, and complex experimental thinking that has facilitated the scientific and technological advances that have radically changed the world. The article suggests that life, human beings, global society, and all that constitutes health be considered as adaptive complex systems. This idea, in turn, prioritizes the adoption of a different approach that seeks to expand understanding. When this rationale is recognized, the principal characteristics and emerging properties of health as an adaptive complex system are sustained, following a care and services delivery model. Finally, some pertinent questions from this perspective are put forward in terms of research, and a series of appraisals are expressed that will hopefully serve to help us understand all that we have become as individuals and as a species. The article proposes that the delivery of health care services be regarded as an adaptive complex system.

  15. A Comparison of a Brain-Based Adaptive System and a Manual Adaptable System for Invoking Automation

    NASA Technical Reports Server (NTRS)

    Bailey, Nathan R.; Scerbo, Mark W.; Freeman, Frederick G.; Mikulka, Peter J.; Scott, Lorissa A.

    2004-01-01

    Two experiments are presented that examine alternative methods for invoking automation. In each experiment, participants were asked to perform simultaneously a monitoring task and a resource management task as well as a tracking task that changed between automatic and manual modes. The monitoring task required participants to detect failures of an automated system to correct aberrant conditions under either high or low system reliability. Performance on each task was assessed as well as situation awareness and subjective workload. In the first experiment, half of the participants worked with a brain-based system that used their EEG signals to switch the tracking task between automatic and manual modes. The remaining participants were yoked to participants from the adaptive condition and received the same schedule of mode switches, but their EEG had no effect on the automation. Within each group, half of the participants were assigned to either the low or high reliability monitoring task. In addition, within each combination of automation invocation and system reliability, participants were separated into high and low complacency potential groups. The results revealed no significant effects of automation invocation on the performance measures; however, the high complacency individuals demonstrated better situation awareness when working with the adaptive automation system. The second experiment was the same as the first with one important exception. Automation was invoked manually. Thus, half of the participants pressed a button to invoke automation for 10 s. The remaining participants were yoked to participants from the adaptable condition and received the same schedule of mode switches, but they had no control over the automation. The results showed that participants who could invoke automation performed more poorly on the resource management task and reported higher levels of subjective workload. Further, those who invoked automation more frequently performed

  16. An adaptive load-following control system for a space nuclear power system

    NASA Astrophysics Data System (ADS)

    Metzger, John D.; El-Genk, Mohamed S.

    An adaptive load-following control system is proposed for a space nuclear power system. The conceptual design of the SP-100 space nuclear power system proposes operating the nuclear reactor at a base thermal power and accommodating changes in the electrical power demand with a shunt regulator. It is necessary to increase the reactor thermal power if the payload electrical demand exceeds the peak system electrical output for the associated reactor power. When it is necessary to change the nuclear reactor power to meet a change in the power demand, the power ascension or descension must be accomplished in a predetermined manner to avoid thermal stresses in the system and to achieve the desired reactor period. The load-following control system described has the ability to adapt to changes in the system and to changes in the satellite environment. The application is proposed of the model reference adaptive control (MRAC). The adaptive control system has the ability to control the dynamic response of nonlinear systems. Three basic subsets of adaptive control are: (1) gain scheduling, (2) self-tuning regulators, and (3) model reference adaptive control.

  17. Adaptive Behaviour Assessment System: Indigenous Australian Adaptation Model (ABAS: IAAM)

    ERIC Educational Resources Information Center

    du Plessis, Santie

    2015-01-01

    The study objectives were to develop, trial and evaluate a cross-cultural adaptation of the Adaptive Behavior Assessment System-Second Edition Teacher Form (ABAS-II TF) ages 5-21 for use with Indigenous Australian students ages 5-14. This study introduced a multiphase mixed-method design with semi-structured and informal interviews, school…

  18. Adaptive System Modeling for Spacecraft Simulation

    NASA Technical Reports Server (NTRS)

    Thomas, Justin

    2011-01-01

    This invention introduces a methodology and associated software tools for automatically learning spacecraft system models without any assumptions regarding system behavior. Data stream mining techniques were used to learn models for critical portions of the International Space Station (ISS) Electrical Power System (EPS). Evaluation on historical ISS telemetry data shows that adaptive system modeling reduces simulation error anywhere from 50 to 90 percent over existing approaches. The purpose of the methodology is to outline how someone can create accurate system models from sensor (telemetry) data. The purpose of the software is to support the methodology. The software provides analysis tools to design the adaptive models. The software also provides the algorithms to initially build system models and continuously update them from the latest streaming sensor data. The main strengths are as follows: Creates accurate spacecraft system models without in-depth system knowledge or any assumptions about system behavior. Automatically updates/calibrates system models using the latest streaming sensor data. Creates device specific models that capture the exact behavior of devices of the same type. Adapts to evolving systems. Can reduce computational complexity (faster simulations).

  19. Adaptive protection algorithm and system

    DOEpatents

    Hedrick, Paul [Pittsburgh, PA; Toms, Helen L [Irwin, PA; Miller, Roger M [Mars, PA

    2009-04-28

    An adaptive protection algorithm and system for protecting electrical distribution systems traces the flow of power through a distribution system, assigns a value (or rank) to each circuit breaker in the system and then determines the appropriate trip set points based on the assigned rank.

  20. Adaptive Decision Aiding in Computer-Assisted Instruction: Adaptive Computerized Training System (ACTS).

    ERIC Educational Resources Information Center

    Hopf-Weichel, Rosemarie; And Others

    This report describes results of the first year of a three-year program to develop and evaluate a new Adaptive Computerized Training System (ACTS) for electronics maintenance training. (ACTS incorporates an adaptive computer program that learns the student's diagnostic and decision value structure, compares it to that of an expert, and adapts the…

  1. Accident/Mishap Investigation System

    NASA Technical Reports Server (NTRS)

    Keller, Richard; Wolfe, Shawn; Gawdiak, Yuri; Carvalho, Robert; Panontin, Tina; Williams, James; Sturken, Ian

    2007-01-01

    InvestigationOrganizer (IO) is a Web-based collaborative information system that integrates the generic functionality of a database, a document repository, a semantic hypermedia browser, and a rule-based inference system with specialized modeling and visualization functionality to support accident/mishap investigation teams. This accessible, online structure is designed to support investigators by allowing them to make explicit, shared, and meaningful links among evidence, causal models, findings, and recommendations.

  2. The Limits to Adaptation; A Systems Approach

    EPA Science Inventory

    The Limits to Adaptation: A Systems Approach. The ability to adapt to climate change is delineated by capacity thresholds, after which climate damages begin to overwhelm the adaptation response. Such thresholds depend upon physical properties (natural processes and engineering...

  3. Meeting the Needs of Teachers and Students within the CESAR Training System.

    ERIC Educational Resources Information Center

    Diaz, Paloma; Aedo, Ignacio; Torra, Nuria; Miranda, Pilar; Martin, Maria

    1998-01-01

    Describes the CESAR training system, a hypermedia learning environment for hearing-impaired children that has been developed by a multidisciplinary team. Discusses the design principles to define the training material; and creating and using the material. (AEF)

  4. Adaptive control system having hedge unit and related apparatus and methods

    NASA Technical Reports Server (NTRS)

    Johnson, Eric Norman (Inventor); Calise, Anthony J. (Inventor)

    2003-01-01

    The invention includes an adaptive control system used to control a plant. The adaptive control system includes a hedge unit that receives at least one control signal and a plant state signal. The hedge unit generates a hedge signal based on the control signal, the plant state signal, and a hedge model including a first model having one or more characteristics to which the adaptive control system is not to adapt, and a second model not having the characteristic(s) to which the adaptive control system is not to adapt. The hedge signal is used in the adaptive control system to remove the effect of the characteristic from a signal supplied to an adaptation law unit of the adaptive control system so that the adaptive control system does not adapt to the characteristic in controlling the plant.

  5. Water System Adaptation To Hydrological Changes: Module 12, Models and Tools for Stormwater and Wastewater System Adaptation

    EPA Science Inventory

    This course will introduce students to the fundamental principles of water system adaptation to hydrological changes, with emphasis on data analysis and interpretation, technical planning, and computational modeling. Starting with real-world scenarios and adaptation needs, the co...

  6. Data-Adaptable Modeling and Optimization for Runtime Adaptable Systems

    DTIC Science & Technology

    2016-06-08

    execution scenarios e . Enables model -guided optimization algorithms that outperform state-of-the-art f. Understands the overhead of system...the Data-Adaptable System Model (DASM), that facilitates design by enabling the designer to: 1) specify both an application’s task flow as well as...systems. The MILAN [3] framework specializes in the design, simulation , and synthesis of System On Chip (SoC) applications using model -based techniques

  7. CRISPR adaptive immune systems of Archaea

    PubMed Central

    Vestergaard, Gisle; Garrett, Roger A; Shah, Shiraz A

    2014-01-01

    CRISPR adaptive immune systems were analyzed for all available completed genomes of archaea, which included representatives of each of the main archaeal phyla. Initially, all proteins encoded within, and proximal to, CRISPR-cas loci were clustered and analyzed using a profile–profile approach. Then cas genes were assigned to gene cassettes and to functional modules for adaptation and interference. CRISPR systems were then classified primarily on the basis of their concatenated Cas protein sequences and gene synteny of the interference modules. With few exceptions, they could be assigned to the universal Type I or Type III systems. For Type I, subtypes I-A, I-B, and I-D dominate but the data support the division of subtype I-B into two subtypes, designated I-B and I-G. About 70% of the Type III systems fall into the universal subtypes III-A and III-B but the remainder, some of which are phyla-specific, diverge significantly in Cas protein sequences, and/or gene synteny, and they are classified separately. Furthermore, a few CRISPR systems that could not be assigned to Type I or Type III are categorized as variant systems. Criteria are presented for assigning newly sequenced archaeal CRISPR systems to the different subtypes. Several accessory proteins were identified that show a specific gene linkage, especially to Type III interference modules, and these may be cofunctional with the CRISPR systems. Evidence is presented for extensive exchange having occurred between adaptation and interference modules of different archaeal CRISPR systems, indicating the wide compatibility of the functionally diverse interference complexes with the relatively conserved adaptation modules. PMID:24531374

  8. Human Systems Center Products and Progress.

    DTIC Science & Technology

    1993-10-01

    and (CASHE:PVS). CASHE:PVS version 1.0 is a CD-ROM- As a precursor to developing collaborative based hypermedia- ergonomic information base design...computer-generated image to determine if the Crew System Ergonomics Information Analysis activity is physically possible. Expert system Center known as...and facility issues relative Federal Drug Administration, and Centers for to dentistry . The scope includes technical Disease Control to establish

  9. Managing Schools as Complex Adaptive Systems: A Strategic Perspective

    ERIC Educational Resources Information Center

    Fidan, Tuncer; Balci, Ali

    2017-01-01

    This conceptual study examines the analogies between schools and complex adaptive systems and identifies strategies used to manage schools as complex adaptive systems. Complex adaptive systems approach, introduced by the complexity theory, requires school administrators to develop new skills and strategies to realize their agendas in an…

  10. Systems and Methods for Derivative-Free Adaptive Control

    NASA Technical Reports Server (NTRS)

    Calise, Anthony J. (Inventor); Yucelen, Tansel (Inventor); Kim, Kilsoo (Inventor)

    2015-01-01

    An adaptive control system is disclosed. The control system can control uncertain dynamic systems. The control system can employ one or more derivative-free adaptive control architectures. The control system can further employ one or more derivative-free weight update laws. The derivative-free weight update laws can comprise a time-varying estimate of an ideal vector of weights. The control system of the present invention can therefore quickly stabilize systems that undergo sudden changes in dynamics, caused by, for example, sudden changes in weight. Embodiments of the present invention can also provide a less complex control system than existing adaptive control systems. The control system can control aircraft and other dynamic systems, such as, for example, those with non-minimum phase dynamics.

  11. The Computerized Adaptive Testing System Development Project.

    ERIC Educational Resources Information Center

    McBride, James R.; Sympson, J. B.

    The Computerized Adaptive Testing (CAT) project is a joint Armed Services coordinated effort to develop and evaluate a system for automated, adaptive administration of the Armed Services Vocational Aptitude Battery (ASVAB). The CAT is a system for administering personnel tests that differs from conventional test administration in two major…

  12. Water System Adaptation To Hydrological Changes: Module 7, Adaptation Principles and Considerations

    EPA Science Inventory

    This course will introduce students to the fundamental principles of water system adaptation to hydrological changes, with emphasis on data analysis and interpretation, technical planning, and computational modeling. Starting with real-world scenarios and adaptation needs, the co...

  13. Inherent robustness of discrete-time adaptive control systems

    NASA Technical Reports Server (NTRS)

    Ma, C. C. H.

    1986-01-01

    Global stability robustness with respect to unmodeled dynamics, arbitrary bounded internal noise, as well as external disturbance is shown to exist for a class of discrete-time adaptive control systems when the regressor vectors of these systems are persistently exciting. Although fast adaptation is definitely undesirable, so far as attaining the greatest amount of global stability robustness is concerned, slow adaptation is shown to be not necessarily beneficial. The entire analysis in this paper holds for systems with slowly varying return difference matrices; the plants in these systems need not be slowly varying.

  14. Adaptive synchronization and anticipatory dynamical systems.

    PubMed

    Yang, Ying-Jen; Chen, Chun-Chung; Lai, Pik-Yin; Chan, C K

    2015-09-01

    Many biological systems can sense periodical variations in a stimulus input and produce well-timed, anticipatory responses after the input is removed. Such systems show memory effects for retaining timing information in the stimulus and cannot be understood from traditional synchronization consideration of passive oscillatory systems. To understand this anticipatory phenomena, we consider oscillators built from excitable systems with the addition of an adaptive dynamics. With such systems, well-timed post-stimulus responses similar to those from experiments can be obtained. Furthermore, a well-known model of working memory is shown to possess similar anticipatory dynamics when the adaptive mechanism is identified with synaptic facilitation. The last finding suggests that this type of oscillator can be common in neuronal systems with plasticity.

  15. Adaptive synchronization and anticipatory dynamical systems

    NASA Astrophysics Data System (ADS)

    Yang, Ying-Jen; Chen, Chun-Chung; Lai, Pik-Yin; Chan, C. K.

    2015-09-01

    Many biological systems can sense periodical variations in a stimulus input and produce well-timed, anticipatory responses after the input is removed. Such systems show memory effects for retaining timing information in the stimulus and cannot be understood from traditional synchronization consideration of passive oscillatory systems. To understand this anticipatory phenomena, we consider oscillators built from excitable systems with the addition of an adaptive dynamics. With such systems, well-timed post-stimulus responses similar to those from experiments can be obtained. Furthermore, a well-known model of working memory is shown to possess similar anticipatory dynamics when the adaptive mechanism is identified with synaptic facilitation. The last finding suggests that this type of oscillator can be common in neuronal systems with plasticity.

  16. Hypermedia: Design and Application. A Select ERIC Bibliography Prepared Especially for the National Conference and Exhibition of the American Association of School Librarians (5th, Salt Lake City, Utah, October 18-22, 1989). Mini-Bib.

    ERIC Educational Resources Information Center

    Preston, Nancy R., Comp.

    The nine references in this bibliography were selected through a computer search of the Educational Resources Information Center (ERIC) database. The following titles are included: (1) "Multimedia in Education" (Sueann Ambron and Kristina Hooper); (2) "Hypermedia in Academia" (Robert Beck and Donald Spicer); (3) "Design Considerations for…

  17. Managing adaptively for multifunctionality in agricultural systems.

    PubMed

    Hodbod, Jennifer; Barreteau, Olivier; Allen, Craig; Magda, Danièle

    2016-12-01

    The critical importance of agricultural systems for food security and as a dominant global landcover requires management that considers the full dimensions of system functions at appropriate scales, i.e. multifunctionality. We propose that adaptive management is the most suitable management approach for such goals, given its ability to reduce uncertainty over time and support multiple objectives within a system, for multiple actors. As such, adaptive management may be the most appropriate method for sustainably intensifying production whilst increasing the quantity and quality of ecosystem services. However, the current assessment of performance of agricultural systems doesn't reward ecosystem service provision. Therefore, we present an overview of the ecosystem functions agricultural systems should and could provide, coupled with a revised definition for assessing the performance of agricultural systems from a multifunctional perspective that, when all satisfied, would create adaptive agricultural systems that can increase production whilst ensuring food security and the quantity and quality of ecosystem services. The outcome of this high level of performance is the capacity to respond to multiple shocks without collapse, equity and triple bottom line sustainability. Through the assessment of case studies, we find that alternatives to industrialized agricultural systems incorporate more functional goals, but that there are mixed findings as to whether these goals translate into positive measurable outcomes. We suggest that an adaptive management perspective would support the implementation of a systematic analysis of the social, ecological and economic trade-offs occurring within such systems, particularly between ecosystem services and functions, in order to provide suitable and comparable assessments. We also identify indicators to monitor performance at multiple scales in agricultural systems which can be used within an adaptive management framework to increase

  18. Managing adaptively for multifunctionality in agricultural systems

    USGS Publications Warehouse

    Hodbod, Jennifer; Barreteau, Olivier; Allen, Craig R.; Magda, Danièle

    2016-01-01

    The critical importance of agricultural systems for food security and as a dominant global landcover requires management that considers the full dimensions of system functions at appropriate scales, i.e. multifunctionality. We propose that adaptive management is the most suitable management approach for such goals, given its ability to reduce uncertainty over time and support multiple objectives within a system, for multiple actors. As such, adaptive management may be the most appropriate method for sustainably intensifying production whilst increasing the quantity and quality of ecosystem services. However, the current assessment of performance of agricultural systems doesn’t reward ecosystem service provision. Therefore, we present an overview of the ecosystem functions agricultural systems should and could provide, coupled with a revised definition for assessing the performance of agricultural systems from a multifunctional perspective that, when all satisfied, would create adaptive agricultural systems that can increase production whilst ensuring food security and the quantity and quality of ecosystem services. The outcome of this high level of performance is the capacity to respond to multiple shocks without collapse, equity and triple bottom line sustainability. Through the assessment of case studies, we find that alternatives to industrialized agricultural systems incorporate more functional goals, but that there are mixed findings as to whether these goals translate into positive measurable outcomes. We suggest that an adaptive management perspective would support the implementation of a systematic analysis of the social, ecological and economic trade-offs occurring within such systems, particularly between ecosystem services and functions, in order to provide suitable and comparable assessments. We also identify indicators to monitor performance at multiple scales in agricultural systems which can be used within an adaptive management framework to

  19. 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…

  20. MHEG Based Distance Learning System on Information Superhighway.

    ERIC Educational Resources Information Center

    Lee, SeiHoon; Yoon, KyungSeob; Wang, ChangJong

    As the need for distance education grows, requirements for the development of high-speed network-based real-time distance learning systems increases. MHEG-5 is the fifth part of the MHEG (Multimedia and Hypermedia information coding Experts Group) standard, and it defines a final-form representation for application interchange. This paper…

  1. Utilizing feedback in adaptive SAR ATR systems

    NASA Astrophysics Data System (ADS)

    Horsfield, Owen; Blacknell, David

    2009-05-01

    Existing SAR ATR systems are usually trained off-line with samples of target imagery or CAD models, prior to conducting a mission. If the training data is not representative of mission conditions, then poor performance may result. In addition, it is difficult to acquire suitable training data for the many target types of interest. The Adaptive SAR ATR Problem Set (AdaptSAPS) program provides a MATLAB framework and image database for developing systems that adapt to mission conditions, meaning less reliance on accurate training data. A key function of an adaptive system is the ability to utilise truth feedback to improve performance, and it is this feature which AdaptSAPS is intended to exploit. This paper presents a new method for SAR ATR that does not use training data, based on supervised learning. This is achieved by using feature-based classification, and several new shadow features have been developed for this purpose. These features allow discrimination of vehicles from clutter, and classification of vehicles into two classes: targets, comprising military combat types, and non-targets, comprising bulldozers and trucks. The performance of the system is assessed using three baseline missions provided with AdaptSAPS, as well as three additional missions. All performance metrics indicate a distinct learning trend over the course of a mission, with most third and fourth quartile performance levels exceeding 85% correct classification. It has been demonstrated that these performance levels can be maintained even when truth feedback rates are reduced by up to 55% over the course of a mission.

  2. Adaptive P300 based control system

    PubMed Central

    Jin, Jing; Allison, Brendan Z.; Sellers, Eric W.; Brunner, Clemens; Horki, Petar; Wang, Xingyu; Neuper, Christa

    2015-01-01

    An adaptive P300 brain-computer interface (BCI) using a 12 × 7 matrix explored new paradigms to improve bit rate and accuracy. During online use, the system adaptively selects the number of flashes to average. Five different flash patterns were tested. The 19-flash paradigm represents the typical row/column presentation (i.e., 12 columns and 7 rows). The 9- and 14-flash A & B paradigms present all items of the 12 × 7 matrix three times using either nine or 14 flashes (instead of 19), decreasing the amount of time to present stimuli. Compared to 9-flash A, 9-flash B decreased the likelihood that neighboring items would flash when the target was not flashing, thereby reducing interference from items adjacent to targets. 14-flash A also reduced adjacent item interference and 14-flash B additionally eliminated successive (double) flashes of the same item. Results showed that accuracy and bit rate of the adaptive system were higher than the non-adaptive system. In addition, 9- and 14-flash B produced significantly higher performance than their respective A conditions. The results also show the trend that the 14-flash B paradigm was better than the 19-flash pattern for naïve users. PMID:21474877

  3. Adaptive Control for Microgravity Vibration Isolation System

    NASA Technical Reports Server (NTRS)

    Yang, Bong-Jun; Calise, Anthony J.; Craig, James I.; Whorton, Mark S.

    2005-01-01

    Most active vibration isolation systems that try to a provide quiescent acceleration environment for space science experiments have utilized linear design methods. In this paper, we address adaptive control augmentation of an existing classical controller that employs a high-gain acceleration feedback together with a low-gain position feedback to center the isolated platform. The control design feature includes parametric and dynamic uncertainties because the hardware of the isolation system is built as a payload-level isolator, and the acceleration Sensor exhibits a significant bias. A neural network is incorporated to adaptively compensate for the system uncertainties, and a high-pass filter is introduced to mitigate the effect of the measurement bias. Simulations show that the adaptive control improves the performance of the existing acceleration controller and keep the level of the isolated platform deviation to that of the existing control system.

  4. Predictable and Adaptable Complex Real-Time Systems

    DTIC Science & Technology

    1993-09-30

    Predictable and Adaptable Complex Real - Time Systems Grant or Contract Number: N00014-92-J-1048 Reporting Period: 1 Oct 91 - 30 Sep 93 1... Real - Time Systems Grant or Contract Number: N00014-92-J-1048 Reporting Period: 1 Oct 91 - 30 Sep 93 2. Summary of Technical Progress Our...cs.umass.edu Grant or Contract Title: Predictable and Adaptable Complex Real - Time Systems Grant or Contract Number: N00014-92-J-1048 Reporting Period: 1 Oct 91

  5. Final Report - Regulatory Considerations for Adaptive Systems

    NASA Technical Reports Server (NTRS)

    Wilkinson, Chris; Lynch, Jonathan; Bharadwaj, Raj

    2013-01-01

    This report documents the findings of a preliminary research study into new approaches to the software design assurance of adaptive systems. We suggest a methodology to overcome the software validation and verification difficulties posed by the underlying assumption of non-adaptive software in the requirementsbased- testing verification methods in RTCA/DO-178B and C. An analysis of the relevant RTCA/DO-178B and C objectives is presented showing the reasons for the difficulties that arise in showing satisfaction of the objectives and suggested additional means by which they could be satisfied. We suggest that the software design assurance problem for adaptive systems is principally one of developing correct and complete high level requirements and system level constraints that define the necessary system functional and safety properties to assure the safe use of adaptive systems. We show how analytical techniques such as model based design, mathematical modeling and formal or formal-like methods can be used to both validate the high level functional and safety requirements, establish necessary constraints and provide the verification evidence for the satisfaction of requirements and constraints that supplements conventional testing. Finally the report identifies the follow-on research topics needed to implement this methodology.

  6. Certification Considerations for Adaptive Systems

    NASA Technical Reports Server (NTRS)

    Bhattacharyya, Siddhartha; Cofer, Darren; Musliner, David J.; Mueller, Joseph; Engstrom, Eric

    2015-01-01

    Advanced capabilities planned for the next generation of aircraft, including those that will operate within the Next Generation Air Transportation System (NextGen), will necessarily include complex new algorithms and non-traditional software elements. These aircraft will likely incorporate adaptive control algorithms that will provide enhanced safety, autonomy, and robustness during adverse conditions. Unmanned aircraft will operate alongside manned aircraft in the National Airspace (NAS), with intelligent software performing the high-level decision-making functions normally performed by human pilots. Even human-piloted aircraft will necessarily include more autonomy. However, there are serious barriers to the deployment of new capabilities, especially for those based upon software including adaptive control (AC) and artificial intelligence (AI) algorithms. Current civil aviation certification processes are based on the idea that the correct behavior of a system must be completely specified and verified prior to operation. This report by Rockwell Collins and SIFT documents our comprehensive study of the state of the art in intelligent and adaptive algorithms for the civil aviation domain, categorizing the approaches used and identifying gaps and challenges associated with certification of each approach.

  7. Adaptive fuzzy system for 3-D vision

    NASA Technical Reports Server (NTRS)

    Mitra, Sunanda

    1993-01-01

    An adaptive fuzzy system using the concept of the Adaptive Resonance Theory (ART) type neural network architecture and incorporating fuzzy c-means (FCM) system equations for reclassification of cluster centers was developed. The Adaptive Fuzzy Leader Clustering (AFLC) architecture is a hybrid neural-fuzzy system which learns on-line in a stable and efficient manner. The system uses a control structure similar to that found in the Adaptive Resonance Theory (ART-1) network to identify the cluster centers initially. The initial classification of an input takes place in a two stage process; a simple competitive stage and a distance metric comparison stage. The cluster prototypes are then incrementally updated by relocating the centroid positions from Fuzzy c-Means (FCM) system equations for the centroids and the membership values. The operational characteristics of AFLC and the critical parameters involved in its operation are discussed. The performance of the AFLC algorithm is presented through application of the algorithm to the Anderson Iris data, and laser-luminescent fingerprint image data. The AFLC algorithm successfully classifies features extracted from real data, discrete or continuous, indicating the potential strength of this new clustering algorithm in analyzing complex data sets. The hybrid neuro-fuzzy AFLC algorithm will enhance analysis of a number of difficult recognition and control problems involved with Tethered Satellite Systems and on-orbit space shuttle attitude controller.

  8. Evolution of complex adaptations in molecular systems

    PubMed Central

    Pál, Csaba; Papp, Balázs

    2017-01-01

    A central challenge in evolutionary biology concerns the mechanisms by which complex adaptations arise. Such adaptations depend on the fixation of multiple, highly specific mutations, where intermediate stages of evolution seemingly provide little or no benefit. It is generally assumed that the establishment of complex adaptations is very slow in nature, as evolution of such traits demands special population genetic or environmental circumstances. However, blueprints of complex adaptations in molecular systems are pervasive, indicating that they can readily evolve. We discuss the prospects and limitations of non-adaptive scenarios, which assume multiple neutral or deleterious steps in the evolution of complex adaptations. Next, we examine how complex adaptations can evolve by natural selection in changing environment. Finally, we argue that molecular ’springboards’, such as phenotypic heterogeneity and promiscuous interactions facilitate this process by providing access to new adaptive paths. PMID:28782044

  9. Adaptive pseudolinear compensators of dynamic characteristics of automatic control systems

    NASA Astrophysics Data System (ADS)

    Skorospeshkin, M. V.; Sukhodoev, M. S.; Timoshenko, E. A.; Lenskiy, F. V.

    2016-04-01

    Adaptive pseudolinear gain and phase compensators of dynamic characteristics of automatic control systems are suggested. The automatic control system performance with adaptive compensators has been explored. The efficiency of pseudolinear adaptive compensators in the automatic control systems with time-varying parameters has been demonstrated.

  10. Testing the adaptive value of circadian systems.

    PubMed

    Johnson, Carl Hirschie

    2005-01-01

    Circadian clocks are thought to enhance reproductive fitness. However, most of the evidence that supports the adaptiveness of clocks is not rigorous and falls into the category of "adaptive storytelling." Approaches that an evolutionary biologist would consider appropriate to address this issue are described along with an analysis of the evidence-past and present-that has been evoked to demonstrate the adaptive value of circadian systems.

  11. Chronic infection and the origin of adaptive immune system.

    PubMed

    Usharauli, David

    2010-08-01

    It has been speculated that the rise of the adaptive immune system in jawed vertebrates some 400 million years ago gave them a superior protection to detect and defend against pathogens that became more elusive and/or virulent to the host that had only innate immune system. First, this line of thought implies that adaptive immune system was a new, more sophisticated layer of host defense that operated independently of the innate immune system. Second, the natural consequence of this scenario would be that pathogens would have exercised so strong an evolutionary pressure that eventually no host could have afforded not to have an adaptive immune system. Neither of these arguments is supported by the facts. First, new experimental evidence has firmly established that operation of adaptive immune system is critically dependent on the ability of the innate immune system to detect invader-pathogens and second, the absolute majority of animal kingdom survives just fine with only an innate immune system. Thus, these data raise the dilemma: If innate immune system was sufficient to detect and protect against pathogens, why then did adaptive immune system develop in the first place? In contrast to the innate immune system, the adaptive immune system has one important advantage, precision. By precision I mean the ability of the defense system to detect and remove the target, for example, infected cells, without causing unwanted bystander damage of surrounding tissue. While the target precision per se is not important for short-term immune response, it becomes a critical factor when the immune response is long-lasting, as during chronic infection. In this paper I would like to propose new, "toxic index" hypothesis where I argue that the need to reduce the collateral damage to the tissue during chronic infection(s) was the evolutionary pressure that led to the development of the adaptive immune system. Copyright 2010 Elsevier Ltd. All rights reserved.

  12. Changing Paradigms: From Schooling to Schools as Adaptive Recommendation Systems

    ERIC Educational Resources Information Center

    Petersen, Anne Kristine; Christiansen, Rene B.; Gynther, Karsten

    2017-01-01

    The paper explores a shift in education from educational systems requiring student adaptation to educational recommendation systems adapting to students' individual needs. The paper discusses the concept of adaptation as addressed in educational research and draws on the system theory of Heinz von Foerster to shed light on how the educational…

  13. Water System Adaptation To Hydrological Changes: Module 14, Life Cycle Analysis (LCA) and Prioritization Tools in Water System Adaptation

    EPA Science Inventory

    This course will introduce students to the fundamental principles of water system adaptation to hydrological changes, with emphasis on data analysis and interpretation, technical planning, and computational modeling. Starting with real-world scenarios and adaptation needs, the co...

  14. Application of Complex Adaptive Systems in Portfolio Management

    ERIC Educational Resources Information Center

    Su, Zheyuan

    2017-01-01

    Simulation-based methods are becoming a promising research tool in financial markets. A general Complex Adaptive System can be tailored to different application scenarios. Based on the current research, we built two models that would benefit portfolio management by utilizing Complex Adaptive Systems (CAS) in Agent-based Modeling (ABM) approach.…

  15. Intermedia: A System for Linking Multimedia Documents. IRIS Technical Report 86-2.

    ERIC Educational Resources Information Center

    Yankelovich, Nicole

    "Intermedia" is a hypermedia system which was developed for use in university research and teaching. It provides a framework for object-oriented, direct manipulation editors and applications, and the capability to link together materials created with those applications. Instructors are able to construct exploratory environments for their…

  16. A reduced adaptive observer for multivariable systems. [using reduced dynamic ordering

    NASA Technical Reports Server (NTRS)

    Carroll, R. L.; Lindorff, D. P.

    1973-01-01

    An adaptive observer for multivariable systems is presented for which the dynamic order of the observer is reduced, subject to mild restrictions. The observer structure depends directly upon the multivariable structure of the system rather than a transformation to a single-output system. The number of adaptive gains is at most the sum of the order of the system and the number of input parameters being adapted. Moreover, for the relatively frequent specific cases for which the number of required adaptive gains is less than the sum of system order and input parameters, the number of these gains is easily determined by inspection of the system structure. This adaptive observer possesses all the properties ascribed to the single-input single-output adpative observer. Like the other adaptive observers some restriction is required of the allowable system command input to guarantee convergence of the adaptive algorithm, but the restriction is more lenient than that required by the full-order multivariable observer. This reduced observer is not restricted to cycle systems.

  17. Verification and Validation Challenges for Adaptive Flight Control of Complex Autonomous Systems

    NASA Technical Reports Server (NTRS)

    Nguyen, Nhan T.

    2018-01-01

    Autonomy of aerospace systems requires the ability for flight control systems to be able to adapt to complex uncertain dynamic environment. In spite of the five decades of research in adaptive control, the fact still remains that currently no adaptive control system has ever been deployed on any safety-critical or human-rated production systems such as passenger transport aircraft. The problem lies in the difficulty with the certification of adaptive control systems since existing certification methods cannot readily be used for nonlinear adaptive control systems. Research to address the notion of metrics for adaptive control began to appear in the recent years. These metrics, if accepted, could pave a path towards certification that would potentially lead to the adoption of adaptive control as a future control technology for safety-critical and human-rated production systems. Development of certifiable adaptive control systems represents a major challenge to overcome. Adaptive control systems with learning algorithms will never become part of the future unless it can be proven that they are highly safe and reliable. Rigorous methods for adaptive control software verification and validation must therefore be developed to ensure that adaptive control system software failures will not occur, to verify that the adaptive control system functions as required, to eliminate unintended functionality, and to demonstrate that certification requirements imposed by regulatory bodies such as the Federal Aviation Administration (FAA) can be satisfied. This presentation will discuss some of the technical issues with adaptive flight control and related V&V challenges.

  18. Optimal Control Modification Adaptive Law for Time-Scale Separated Systems

    NASA Technical Reports Server (NTRS)

    Nguyen, Nhan T.

    2010-01-01

    Recently a new optimal control modification has been introduced that can achieve robust adaptation with a large adaptive gain without incurring high-frequency oscillations as with the standard model-reference adaptive control. This modification is based on an optimal control formulation to minimize the L2 norm of the tracking error. The optimal control modification adaptive law results in a stable adaptation in the presence of a large adaptive gain. This study examines the optimal control modification adaptive law in the context of a system with a time scale separation resulting from a fast plant with a slow actuator. A singular perturbation analysis is performed to derive a modification to the adaptive law by transforming the original system into a reduced-order system in slow time. A model matching conditions in the transformed time coordinate results in an increase in the actuator command that effectively compensate for the slow actuator dynamics. Simulations demonstrate effectiveness of the method.

  19. Adaptive mechanism-based congestion control for networked systems

    NASA Astrophysics Data System (ADS)

    Liu, Zhi; Zhang, Yun; Chen, C. L. Philip

    2013-03-01

    In order to assure the communication quality in network systems with heavy traffic and limited bandwidth, a new ATRED (adaptive thresholds random early detection) congestion control algorithm is proposed for the congestion avoidance and resource management of network systems. Different to the traditional AQM (active queue management) algorithms, the control parameters of ATRED are not configured statically, but dynamically adjusted by the adaptive mechanism. By integrating with the adaptive strategy, ATRED alleviates the tuning difficulty of RED (random early detection) and shows a better control on the queue management, and achieve a more robust performance than RED under varying network conditions. Furthermore, a dynamic transmission control protocol-AQM control system using ATRED controller is introduced for the systematic analysis. It is proved that the stability of the network system can be guaranteed when the adaptive mechanism is finely designed. Simulation studies show the proposed ATRED algorithm achieves a good performance in varying network environments, which is superior to the RED and Gentle-RED algorithm, and providing more reliable service under varying network conditions.

  20. Adaptive, full-spectrum solar energy system

    DOEpatents

    Muhs, Jeffrey D.; Earl, Dennis D.

    2003-08-05

    An adaptive full spectrum solar energy system having at least one hybrid solar concentrator, at least one hybrid luminaire, at least one hybrid photobioreactor, and a light distribution system operably connected to each hybrid solar concentrator, each hybrid luminaire, and each hybrid photobioreactor. A lighting control system operates each component.

  1. Adaptive CT scanning system

    DOEpatents

    Sampayan, Stephen E.

    2016-11-22

    Apparatus, systems, and methods that provide an X-ray interrogation system having a plurality of stationary X-ray point sources arranged to substantially encircle an area or space to be interrogated. A plurality of stationary detectors are arranged to substantially encircle the area or space to be interrogated, A controller is adapted to control the stationary X-ray point sources to emit X-rays one at a time, and to control the stationary detectors to detect the X-rays emitted by the stationary X-ray point sources.

  2. An Analysis of Minimum System Requirements to Support Computerized Adaptive Testing.

    DTIC Science & Technology

    1986-09-01

    adaptive test ( CAT ); adaptive test ing A;4SRAC:’ (Continue on reverie of necessary and ident4f by block number) % This pape-r discusses the minimum system...requirements needed to develop a computerized adaptive test ( CAT ). It lists some of the benefits of adaptive testing, establishes a set of...discusses the minimum system requirements needed to develop a computerized adaptive test ( CAT ). It lists some of the benefits of adaptive testing

  3. Adaptive structures for precision controlled large space systems

    NASA Technical Reports Server (NTRS)

    Garba, John A.; Wada, Ben K.; Fanson, James L.

    1991-01-01

    The stringent accuracy and ground test validation requirements of some of the future space missions will require new approaches in structural design. Adaptive structures, structural systems that can vary their geometric congiguration as well as their physical properties, are primary candidates for meeting the functional requirements for such missions. Research performed in the development of such adaptive structural systems is described.

  4. Restricted Complexity Framework for Nonlinear Adaptive Control in Complex Systems

    NASA Astrophysics Data System (ADS)

    Williams, Rube B.

    2004-02-01

    Control law adaptation that includes implicit or explicit adaptive state estimation, can be a fundamental underpinning for the success of intelligent control in complex systems, particularly during subsystem failures, where vital system states and parameters can be impractical or impossible to measure directly. A practical algorithm is proposed for adaptive state filtering and control in nonlinear dynamic systems when the state equations are unknown or are too complex to model analytically. The state equations and inverse plant model are approximated by using neural networks. A framework for a neural network based nonlinear dynamic inversion control law is proposed, as an extrapolation of prior developed restricted complexity methodology used to formulate the adaptive state filter. Examples of adaptive filter performance are presented for an SSME simulation with high pressure turbine failure to support extrapolations to adaptive control problems.

  5. Adapting ISA system warnings to enhance user acceptance.

    PubMed

    Jiménez, Felipe; Liang, Yingzhen; Aparicio, Francisco

    2012-09-01

    Inappropriate speed is a major cause of traffic accidents. Different measures have been considered to control traffic speed, and intelligent speed adaptation (ISA) systems are one of the alternatives. These systems know the speed limits and try to improve compliance with them. This paper deals with an informative ISA system that provides the driver with an advance warning before reaching a road section with singular characteristics that require a lower safe speed than the current speed. In spite of the extensive tests performed using ISA systems, few works show how warnings can be adapted to the driver. This paper describes a method to adapt warning parameters (safe speed on curves, zone of influence of a singular stretch, deceleration process and reaction time) to normal driving behavior. The method is based on a set of tests with and without the ISA system. This adjustment, as well as the analysis of driver acceptance before and after the adaptation and changes in driver behavior (changes in speed and path) resulting from the tested ISA regarding a driver's normal driving style, is shown in this paper. The main conclusion is that acceptance by drivers increased significantly after redefining the warning parameters, but the effect of speed homogenization was not reduced. Copyright © 2010 Elsevier Ltd. All rights reserved.

  6. Optimizing Input/Output Using Adaptive File System Policies

    NASA Technical Reports Server (NTRS)

    Madhyastha, Tara M.; Elford, Christopher L.; Reed, Daniel A.

    1996-01-01

    Parallel input/output characterization studies and experiments with flexible resource management algorithms indicate that adaptivity is crucial to file system performance. In this paper we propose an automatic technique for selecting and refining file system policies based on application access patterns and execution environment. An automatic classification framework allows the file system to select appropriate caching and pre-fetching policies, while performance sensors provide feedback used to tune policy parameters for specific system environments. To illustrate the potential performance improvements possible using adaptive file system policies, we present results from experiments involving classification-based and performance-based steering.

  7. Architecture for Adaptive Intelligent Systems

    NASA Technical Reports Server (NTRS)

    Hayes-Roth, Barbara

    1993-01-01

    We identify a class of niches to be occupied by 'adaptive intelligent systems (AISs)'. In contrast with niches occupied by typical AI agents, AIS niches present situations that vary dynamically along several key dimensions: different combinations of required tasks, different configurations of available resources, contextual conditions ranging from benign to stressful, and different performance criteria. We present a small class hierarchy of AIS niches that exhibit these dimensions of variability and describe a particular AIS niche, ICU (intensive care unit) patient monitoring, which we use for illustration throughout the paper. We have designed and implemented an agent architecture that supports all of different kinds of adaptation by exploiting a single underlying theoretical concept: An agent dynamically constructs explicit control plans to guide its choices among situation-triggered behaviors. We illustrate the architecture and its support for adaptation with examples from Guardian, an experimental agent for ICU monitoring.

  8. Adaptive Neural Network Based Control of Noncanonical Nonlinear Systems.

    PubMed

    Zhang, Yanjun; Tao, Gang; Chen, Mou

    2016-09-01

    This paper presents a new study on the adaptive neural network-based control of a class of noncanonical nonlinear systems with large parametric uncertainties. Unlike commonly studied canonical form nonlinear systems whose neural network approximation system models have explicit relative degree structures, which can directly be used to derive parameterized controllers for adaptation, noncanonical form nonlinear systems usually do not have explicit relative degrees, and thus their approximation system models are also in noncanonical forms. It is well-known that the adaptive control of noncanonical form nonlinear systems involves the parameterization of system dynamics. As demonstrated in this paper, it is also the case for noncanonical neural network approximation system models. Effective control of such systems is an open research problem, especially in the presence of uncertain parameters. This paper shows that it is necessary to reparameterize such neural network system models for adaptive control design, and that such reparameterization can be realized using a relative degree formulation, a concept yet to be studied for general neural network system models. This paper then derives the parameterized controllers that guarantee closed-loop stability and asymptotic output tracking for noncanonical form neural network system models. An illustrative example is presented with the simulation results to demonstrate the control design procedure, and to verify the effectiveness of such a new design method.

  9. Adaptive functional systems: learning with chaos.

    PubMed

    Komarov, M A; Osipov, G V; Burtsev, M S

    2010-12-01

    We propose a new model of adaptive behavior that combines a winnerless competition principle and chaos to learn new functional systems. The model consists of a complex network of nonlinear dynamical elements producing sequences of goal-directed actions. Each element describes dynamics and activity of the functional system which is supposed to be a distributed set of interacting physiological elements such as nerve or muscle that cooperates to obtain certain goal at the level of the whole organism. During "normal" behavior, the dynamics of the system follows heteroclinic channels, but in the novel situation chaotic search is activated and a new channel leading to the target state is gradually created simulating the process of learning. The model was tested in single and multigoal environments and had demonstrated a good potential for generation of new adaptations. © 2010 American Institute of Physics.

  10. Development of fault tolerant adaptive control laws for aerospace systems

    NASA Astrophysics Data System (ADS)

    Perez Rocha, Andres E.

    The main topic of this dissertation is the design, development and implementation of intelligent adaptive control techniques designed to maintain healthy performance of aerospace systems subjected to malfunctions, external parameter changes and/or unmodeled dynamics. The dissertation is focused on the development of novel adaptive control configurations that rely on non-linear functions that appear in the immune system of living organisms as main source of adaptation. One of the main goals of this dissertation is to demonstrate that these novel adaptive control architectures are able to improve overall performance and protect the system while reducing control effort and maintaining adequate operation outside bounds of nominal design. This research effort explores several phases, ranging from theoretical stability analysis, simulation and hardware implementation on different types of aerospace systems including spacecraft, aircraft and quadrotor vehicles. The results presented in this dissertation are focused on two main adaptivity approaches, the first one is intended for aerospace systems that do not attain large angles and use exact feedback linearization of Euler angle kinematics. A proof of stability is presented by means of the circle Criterion and Lyapunov's direct method. The second approach is intended for aerospace systems that can attain large attitude angles (e.g. space systems in gravity-less environments), the adaptation is incorporated on a baseline architecture that uses partial feedback linearization of quaternions kinematics. In this case, the closed loop stability was analyzed using Lyapunov's direct method and Barbalat's Lemma. It is expected that some results presented in this dissertation can contribute towards the validation and certification of direct adaptive controllers.

  11. Emergent "Quantum" Theory in Complex Adaptive Systems.

    PubMed

    Minic, Djordje; Pajevic, Sinisa

    2016-04-30

    Motivated by the question of stability, in this letter we argue that an effective quantum-like theory can emerge in complex adaptive systems. In the concrete example of stochastic Lotka-Volterra dynamics, the relevant effective "Planck constant" associated with such emergent "quantum" theory has the dimensions of the square of the unit of time. Such an emergent quantum-like theory has inherently non-classical stability as well as coherent properties that are not, in principle, endangered by thermal fluctuations and therefore might be of crucial importance in complex adaptive systems.

  12. Making adaptable systems work for mission operations: A case study

    NASA Technical Reports Server (NTRS)

    Holder, Barbara E.; Levesque, Michael E.

    1993-01-01

    The Advanced Multimission Operations System (AMMOS) at NASA's Jet Propulsion Laboratory is based on a highly adaptable multimission ground data system (MGDS) for mission operations. The goal for MGDS is to support current flight project science and engineering personnel and to meet the demands of future missions while reducing associated operations and software development costs. MGDS has become a powerful and flexible mission operations system by using a network of heterogeneous workstations, emerging open system standards, and selecting an adaptable tools-based architecture. Challenges in developing adaptable systems for mission operations and the benefits of this approach are described.

  13. Development of adaptive control applied to chaotic systems

    NASA Astrophysics Data System (ADS)

    Rhode, Martin Andreas

    1997-12-01

    Continuous-time derivative control and adaptive map-based recursive feedback control techniques are used to control chaos in a variety of systems and in situations that are of practical interest. The theoretical part of the research includes the review of fundamental concept of control theory in the context of its applications to deterministic chaotic systems, the development of a new adaptive algorithm to identify the linear system properties necessary for control, and the extension of the recursive proportional feedback control technique, RPF, to high dimensional systems. Chaos control was applied to models of a thermal pulsed combustor, electro-chemical dissolution and the hyperchaotic Rossler system. Important implications for combustion engineering were suggested by successful control of the model of the thermal pulsed combustor. The system was automatically tracked while maintaining control into regions of parameter and state space where no stable attractors exist. In a simulation of the electrochemical dissolution system, application of derivative control to stabilize a steady state, and adaptive RPF to stabilize a period one orbit, was demonstrated. The high dimensional adaptive control algorithm was applied in a simulation using the Rossler hyperchaotic system, where a period-two orbit with two unstable directions was stabilized and tracked over a wide range of a system parameter. In the experimental part, the electrochemical system was studied in parameter space, by scanning the applied potential and the frequency of the rotating copper disk. The automated control algorithm is demonstrated to be effective when applied to stabilize a period-one orbit in the experiment. We show the necessity of small random perturbations applied to the system in order to both learn the dynamics and control the system at the same time. The simultaneous learning and control capability is shown to be an important part of the active feedback control.

  14. Promoting evaluation capacity building in a complex adaptive system.

    PubMed

    Lawrenz, Frances; Kollmann, Elizabeth Kunz; King, Jean A; Bequette, Marjorie; Pattison, Scott; Nelson, Amy Grack; Cohn, Sarah; Cardiel, Christopher L B; Iacovelli, Stephanie; Eliou, Gayra Ostgaard; Goss, Juli; Causey, Lauren; Sinkey, Anne; Beyer, Marta; Francisco, Melanie

    2018-04-10

    This study provides results from an NSF funded, four year, case study about evaluation capacity building in a complex adaptive system, the Nanoscale Informal Science Education Network (NISE Net). The results of the Complex Adaptive Systems as a Model for Network Evaluations (CASNET) project indicate that complex adaptive system concepts help to explain evaluation capacity building in a network. The NISE Network was found to be a complex learning system that was supportive of evaluation capacity building through feedback loops that provided for information sharing and interaction. Participants in the system had different levels of and sources of evaluation knowledge. To be successful at building capacity, the system needed to have a balance between both centralized and decentralized control, coherence, redundancy, and diversity. Embeddedness of individuals within the system also provided support and moved the capacity of the system forward. Finally, success depended on attention being paid to the control of resources. Implications of these findings are discussed. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. Towards Self-adaptation for Dependable Service-Oriented Systems

    NASA Astrophysics Data System (ADS)

    Cardellini, Valeria; Casalicchio, Emiliano; Grassi, Vincenzo; Lo Presti, Francesco; Mirandola, Raffaela

    Increasingly complex information systems operating in dynamic environments ask for management policies able to deal intelligently and autonomously with problems and tasks. An attempt to deal with these aspects can be found in the Service-Oriented Architecture (SOA) paradigm that foresees the creation of business applications from independently developed services, where services and applications build up complex dependencies. Therefore the dependability of SOA systems strongly depends on their ability to self-manage and adapt themselves to cope with changes in the operating conditions and to meet the required dependability with a minimum of resources. In this paper we propose a model-based approach to the realization of self-adaptable SOA systems, aimed at the fulfillment of dependability requirements. Specifically, we provide a methodology driving the system adaptation and we discuss the architectural issues related to its implementation. To bring this approach to fruition, we developed a prototype tool and we show the results that can be achieved with a simple example.

  16. Adaptive control of artificial pancreas systems - a review.

    PubMed

    Turksoy, Kamuran; Cinar, Ali

    2014-01-01

    Artificial pancreas (AP) systems offer an important improvement in regulating blood glucose concentration for patients with type 1 diabetes, compared to current approaches. AP consists of sensors, control algorithms and an insulin pump. Different AP control algorithms such as proportional-integral-derivative, model-predictive control, adaptive control, and fuzzy logic control have been investigated in simulation and clinical studies in the past three decades. The variability over time and complexity of the dynamics of blood glucose concentration, unsteady disturbances such as meals, time-varying delays on measurements and insulin infusion, and noisy data from sensors create a challenging system to AP. Adaptive control is a powerful control technique that can deal with such challenges. In this paper, a review of adaptive control techniques for blood glucose regulation with an AP system is presented. The investigations and advances in technology produced impressive results, but there is still a need for a reliable AP system that is both commercially viable and appealing to patients with type 1 diabetes.

  17. Predicting Database Requirements for Geographic Information Systems in the Year 2000: Long-Term Design Issues for GRASS

    DTIC Science & Technology

    1992-08-01

    Image Processing. Reading, Massachusetts: Addison-Wesley (1977). Graefe, G., "Parallelizing the Volcano Query Processor," Proc. IEEE COMPCON 90...Approach to a Next Generation of Hypermedia System," Proc. IEEE COMPCON 90 (February 1990), pp 520-527. Jellinghaus, R., " Eiffel Linda: An Object

  18. An Approach to V&V of Embedded Adaptive Systems

    NASA Technical Reports Server (NTRS)

    Liu, Yan; Yerramalla, Sampath; Fuller, Edgar; Cukic, Bojan; Gururajan, Srikaruth

    2004-01-01

    Rigorous Verification and Validation (V&V) techniques are essential for high assurance systems. Lately, the performance of some of these systems is enhanced by embedded adaptive components in order to cope with environmental changes. Although the ability of adapting is appealing, it actually poses a problem in terms of V&V. Since uncertainties induced by environmental changes have a significant impact on system behavior, the applicability of conventional V&V techniques is limited. In safety-critical applications such as flight control system, the mechanisms of change must be observed, diagnosed, accommodated and well understood prior to deployment. In this paper, we propose a non-conventional V&V approach suitable for online adaptive systems. We apply our approach to an intelligent flight control system that employs a particular type of Neural Networks (NN) as the adaptive learning paradigm. Presented methodology consists of a novelty detection technique and online stability monitoring tools. The novelty detection technique is based on Support Vector Data Description that detects novel (abnormal) data patterns. The Online Stability Monitoring tools based on Lyapunov's Stability Theory detect unstable learning behavior in neural networks. Cases studies based on a high fidelity simulator of NASA's Intelligent Flight Control System demonstrate a successful application of the presented V&V methodology. ,

  19. 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.

  20. Real-time control system for adaptive resonator

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Flath, L; An, J; Brase, J

    2000-07-24

    Sustained operation of high average power solid-state lasers currently requires an adaptive resonator to produce the optimal beam quality. We describe the architecture of a real-time adaptive control system for correcting intra-cavity aberrations in a heat capacity laser. Image data collected from a wavefront sensor are processed and used to control phase with a high-spatial-resolution deformable mirror. Our controller takes advantage of recent developments in low-cost, high-performance processor technology. A desktop-based computational engine and object-oriented software architecture replaces the high-cost rack-mount embedded computers of previous systems.

  1. Concept Based Approach for Adaptive Personalized Course Learning System

    ERIC Educational Resources Information Center

    Salahli, Mehmet Ali; Özdemir, Muzaffer; Yasar, Cumali

    2013-01-01

    One of the most important factors for improving the personalization aspects of learning systems is to enable adaptive properties to them. The aim of the adaptive personalized learning system is to offer the most appropriate learning path and learning materials to learners by taking into account their profiles. In this paper, a new approach to…

  2. On advanced configuration enhance adaptive system optimization

    NASA Astrophysics Data System (ADS)

    Liu, Hua; Ding, Quanxin; Wang, Helong; Guo, Chunjie; Chen, Hongliang; Zhou, Liwei

    2017-10-01

    For aim to find an effective method to structure to enhance these adaptive system with some complex function and look forward to establish an universally applicable solution in prototype and optimization. As the most attractive component in adaptive system, wave front corrector is constrained by some conventional technique and components, such as polarization dependence and narrow working waveband. Advanced configuration based on a polarized beam split can optimized energy splitting method used to overcome these problems effective. With the global algorithm, the bandwidth has been amplified by more than five times as compared with that of traditional ones. Simulation results show that the system can meet the application requirements in MTF and other related criteria. Compared with the conventional design, the system has reduced in volume and weight significantly. Therefore, the determining factors are the prototype selection and the system configuration, Results show their effectiveness.

  3. Computer aided systems human engineering: A hypermedia tool

    NASA Technical Reports Server (NTRS)

    Boff, Kenneth R.; Monk, Donald L.; Cody, William J.

    1992-01-01

    The Computer Aided Systems Human Engineering (CASHE) system, Version 1.0, is a multimedia ergonomics database on CD-ROM for the Apple Macintosh II computer, being developed for use by human system designers, educators, and researchers. It will initially be available on CD-ROM and will allow users to access ergonomics data and models stored electronically as text, graphics, and audio. The CASHE CD-ROM, Version 1.0 will contain the Boff and Lincoln (1988) Engineering Data Compendium, MIL-STD-1472D and a unique, interactive simulation capability, the Perception and Performance Prototyper. Its features also include a specialized data retrieval, scaling, and analysis capability and the state of the art in information retrieval, browsing, and navigation.

  4. L(sub 1) Adaptive Flight Control System: Flight Evaluation and Technology Transition

    NASA Technical Reports Server (NTRS)

    Xargay, Enric; Hovakimyan, Naira; Dobrokhodov, Vladimir; Kaminer, Isaac; Gregory, Irene M.; Cao, Chengyu

    2010-01-01

    Certification of adaptive control technologies for both manned and unmanned aircraft represent a major challenge for current Verification and Validation techniques. A (missing) key step towards flight certification of adaptive flight control systems is the definition and development of analysis tools and methods to support Verification and Validation for nonlinear systems, similar to the procedures currently used for linear systems. In this paper, we describe and demonstrate the advantages of L(sub l) adaptive control architectures for closing some of the gaps in certification of adaptive flight control systems, which may facilitate the transition of adaptive control into military and commercial aerospace applications. As illustrative examples, we present the results of a piloted simulation evaluation on the NASA AirSTAR flight test vehicle, and results of an extensive flight test program conducted by the Naval Postgraduate School to demonstrate the advantages of L(sub l) adaptive control as a verifiable robust adaptive flight control system.

  5. Investigating the Effect of Learning Styles in a Blended E-Learning System: An Extension of the Technology Acceptance Model (TAM)

    ERIC Educational Resources Information Center

    Al-Azawei, Ahmed; Parslow, Patrick; Lundqvist, Karsten

    2017-01-01

    This study assesses learner perceptions of a blended e-learning system (BELS) and the feasibility of accommodating educational hypermedia systems (EHSs) according to learning styles using a modified version of the technology acceptance model (TAM). Recently, Moodle has been adopted by an Iraqi university alongside face-to-face (F2F) classrooms to…

  6. A case for Sandia investment in complex adaptive systems science and technology.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Colbaugh, Richard; Tsao, Jeffrey Yeenien; Johnson, Curtis Martin

    2012-05-01

    This white paper makes a case for Sandia National Laboratories investments in complex adaptive systems science and technology (S&T) -- investments that could enable higher-value-added and more-robustly-engineered solutions to challenges of importance to Sandia's national security mission and to the nation. Complex adaptive systems are ubiquitous in Sandia's national security mission areas. We often ignore the adaptive complexity of these systems by narrowing our 'aperture of concern' to systems or subsystems with a limited range of function exposed to a limited range of environments over limited periods of time. But by widening our aperture of concern we could increase ourmore » impact considerably. To do so, the science and technology of complex adaptive systems must mature considerably. Despite an explosion of interest outside of Sandia, however, that science and technology is still in its youth. What has been missing is contact with real (rather than model) systems and real domain-area detail. With its center-of-gravity as an engineering laboratory, Sandia's has made considerable progress applying existing science and technology to real complex adaptive systems. It has focused much less, however, on advancing the science and technology itself. But its close contact with real systems and real domain-area detail represents a powerful strength with which to help complex adaptive systems science and technology mature. Sandia is thus both a prime beneficiary of, as well as potentially a prime contributor to, complex adaptive systems science and technology. Building a productive program in complex adaptive systems science and technology at Sandia will not be trivial, but a credible path can be envisioned: in the short run, continue to apply existing science and technology to real domain-area complex adaptive systems; in the medium run, jump-start the creation of new science and technology capability through Sandia's Laboratory Directed Research and Development

  7. Development of Adaptive Kanji Learning System for Mobile Phone

    ERIC Educational Resources Information Center

    Li, Mengmeng; Ogata, Hiroaki; Hou, Bin; Hashimoto, Satoshi; Liu, Yuqin; Uosaki, Noriko; Yano, Yoneo

    2010-01-01

    This paper describes an adaptive learning system based on mobile phone email to support the study of Japanese Kanji. In this study, the main emphasis is on using the adaptive learning to resolve one common problem of the mobile-based email or SMS language learning systems. To achieve this goal, the authors main efforts focus on three aspects:…

  8. What is adapted in face adaptation? The neural representations of expression in the human visual system.

    PubMed

    Fox, Christopher J; Barton, Jason J S

    2007-01-05

    The neural representation of facial expression within the human visual system is not well defined. Using an adaptation paradigm, we examined aftereffects on expression perception produced by various stimuli. Adapting to a face, which was used to create morphs between two expressions, substantially biased expression perception within the morphed faces away from the adapting expression. This adaptation was not based on low-level image properties, as a different image of the same person displaying that expression produced equally robust aftereffects. Smaller but significant aftereffects were generated by images of different individuals, irrespective of gender. Non-face visual, auditory, or verbal representations of emotion did not generate significant aftereffects. These results suggest that adaptation affects at least two neural representations of expression: one specific to the individual (not the image), and one that represents expression across different facial identities. The identity-independent aftereffect suggests the existence of a 'visual semantic' for facial expression in the human visual system.

  9. Adaptive Control for Uncertain Nonlinear Multi-Input Multi-Output Systems

    NASA Technical Reports Server (NTRS)

    Cao, Chengyu (Inventor); Hovakimyan, Naira (Inventor); Xargay, Enric (Inventor)

    2014-01-01

    Systems and methods of adaptive control for uncertain nonlinear multi-input multi-output systems in the presence of significant unmatched uncertainty with assured performance are provided. The need for gain-scheduling is eliminated through the use of bandwidth-limited (low-pass) filtering in the control channel, which appropriately attenuates the high frequencies typically appearing in fast adaptation situations and preserves the robustness margins in the presence of fast adaptation.

  10. Multilevel adaptive control of nonlinear interconnected systems.

    PubMed

    Motallebzadeh, Farzaneh; Ozgoli, Sadjaad; Momeni, Hamid Reza

    2015-01-01

    This paper presents an adaptive backstepping-based multilevel approach for the first time to control nonlinear interconnected systems with unknown parameters. The system consists of a nonlinear controller at the first level to neutralize the interaction terms, and some adaptive controllers at the second level, in which the gains are optimally tuned using genetic algorithm. The presented scheme can be used in systems with strong couplings where completely ignoring the interactions leads to problems in performance or stability. In order to test the suitability of the method, two case studies are provided: the uncertain double and triple coupled inverted pendulums connected by springs with unknown parameters. The simulation results show that the method is capable of controlling the system effectively, in both regulation and tracking tasks. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

  11. Lessons from Jurassic Park: patients as complex adaptive systems.

    PubMed

    Katerndahl, David A

    2009-08-01

    With realization that non-linearity is generally the rule rather than the exception in nature, viewing patients and families as complex adaptive systems may lead to a better understanding of health and illness. Doctors who successfully practise the 'art' of medicine may recognize non-linear principles at work without having the jargon needed to label them. Complex adaptive systems are systems composed of multiple components that display complexity and adaptation to input. These systems consist of self-organized components, which display complex dynamics, ranging from simple periodicity to chaotic and random patterns showing trends over time. Understanding the non-linear dynamics of phenomena both internal and external to our patients can (1) improve our definition of 'health'; (2) improve our understanding of patients, disease and the systems in which they converge; (3) be applied to future monitoring systems; and (4) be used to possibly engineer change. Such a non-linear view of the world is quite congruent with the generalist perspective.

  12. Fast calibration of high-order adaptive optics systems.

    PubMed

    Kasper, Markus; Fedrigo, Enrico; Looze, Douglas P; Bonnet, Henri; Ivanescu, Liviu; Oberti, Sylvain

    2004-06-01

    We present a new method of calibrating adaptive optics systems that greatly reduces the required calibration time or, equivalently, improves the signal-to-noise ratio. The method uses an optimized actuation scheme with Hadamard patterns and does not scale with the number of actuators for a given noise level in the wavefront sensor channels. It is therefore highly desirable for high-order systems and/or adaptive secondary systems on a telescope without a Gregorian focal plane. In the latter case, the measurement noise is increased by the effects of the turbulent atmosphere when one is calibrating on a natural guide star.

  13. Holographic Adaptive Laser Optics System

    NASA Astrophysics Data System (ADS)

    Andersen, G.; Ghebremichael, F.

    2011-09-01

    We have created a new adaptive optics system using a holographic modal wavefront sensing method with the autonomous (computer-free) closed-loop control of a MEMS deformable mirror (DM). A multiplexed hologram is recorded using the maximum and minimum actuator positions on the deformable mirror as the “modes”. On reconstruction, an input beam is diffracted into pairs of focal spots and the ratio of the intensities of certain pairs determines the absolute wavefront phase at a particular actuator location. The wavefront measurement is made using fast, sensitive silicon photomultiplier arrays with the parallel outputs directly controlling individual actuators in the MEMS DM. In this talk, we will present the results from an all-optical, ultra-compact system that runs in closed-loop without the need for a computer. The speed is limited only by the response time of any given DM actuator and not the number of actuators. In our case, our 32-actuator prototype device already operates at 10 kHz and our next generation system is being designed for > 100 kHz. As a modal system, it is largely insensitive to scintillation and obscuration and is thus ideal for extreme adaptive optics applications. We will present information on how HALOS can be used for image correction and beam propagation as well as several other novel applications.

  14. Adaptive Dialogue Systems for Assistive Living Environments

    ERIC Educational Resources Information Center

    Papangelis, Alexandros

    2013-01-01

    Adaptive Dialogue Systems (ADS) are intelligent systems, able to interact with users via multiple modalities, such as speech, gestures, facial expressions and others. Such systems are able to make conversation with their users, usually on a specific, narrow topic. Assistive Living Environments are environments where the users are by definition not…

  15. Small scale adaptive optics experiment systems engineering

    NASA Technical Reports Server (NTRS)

    Boykin, William H.

    1993-01-01

    Assessment of the current technology relating to the laser power beaming system which in full scale is called the Beam Transmission Optical System (BTOS). Evaluation of system integration efforts are being conducted by the various government agencies and industry. Concepts are being developed for prototypes of adaptive optics for a BTOS.

  16. Note-Taking within MetaTutor: Interactions between an Intelligent Tutoring System and Prior Knowledge on Note-Taking and Learning

    ERIC Educational Resources Information Center

    Trevors, Gregory; Duffy, Melissa; Azevedo, Roger

    2014-01-01

    Hypermedia learning environments (HLE) unevenly present new challenges and opportunities to learning processes and outcomes depending on learner characteristics and instructional supports. In this experimental study, we examined how one such HLE--MetaTutor, an intelligent, multi-agent tutoring system designed to scaffold cognitive and…

  17. Implementation of an Adaptive Learning System Using a Bayesian Network

    ERIC Educational Resources Information Center

    Yasuda, Keiji; Kawashima, Hiroyuki; Hata, Yoko; Kimura, Hiroaki

    2015-01-01

    An adaptive learning system is proposed that incorporates a Bayesian network to efficiently gauge learners' understanding at the course-unit level. Also, learners receive content that is adapted to their measured level of understanding. The system works on an iPad via the Edmodo platform. A field experiment using the system in an elementary school…

  18. An adaptive brain actuated system for augmenting rehabilitation

    PubMed Central

    Roset, Scott A.; Gant, Katie; Prasad, Abhishek; Sanchez, Justin C.

    2014-01-01

    For people living with paralysis, restoration of hand function remains the top priority because it leads to independence and improvement in quality of life. In approaches to restore hand and arm function, a goal is to better engage voluntary control and counteract maladaptive brain reorganization that results from non-use. Standard rehabilitation augmented with developments from the study of brain-computer interfaces could provide a combined therapy approach for motor cortex rehabilitation and to alleviate motor impairments. In this paper, an adaptive brain-computer interface system intended for application to control a functional electrical stimulation (FES) device is developed as an experimental test bed for augmenting rehabilitation with a brain-computer interface. The system's performance is improved throughout rehabilitation by passive user feedback and reinforcement learning. By continuously adapting to the user's brain activity, similar adaptive systems could be used to support clinical brain-computer interface neurorehabilitation over multiple days. PMID:25565945

  19. Convergence of fractional adaptive systems using gradient approach.

    PubMed

    Gallegos, Javier A; Duarte-Mermoud, Manuel A

    2017-07-01

    Conditions for boundedness and convergence of the output error and the parameter error for various Caputo's fractional order adaptive schemes based on the steepest descent method are derived in this paper. To this aim, the concept of sufficiently exciting signals is introduced, characterized and related to the concept of persistently exciting signals used in the integer order case. An application is designed in adaptive indirect control of integer order systems using fractional equations to adjust parameters. This application is illustrated for a pole placement adaptive problem. Advantages of using fractional adjustment in control adaptive schemes are experimentally obtained. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  20. Adaptive control applied to Space Station attitude control system

    NASA Technical Reports Server (NTRS)

    Lam, Quang M.; Chipman, Richard; Hu, Tsay-Hsin G.; Holmes, Eric B.; Sunkel, John

    1992-01-01

    This paper presents an adaptive control approach to enhance the performance of current attitude control system used by the Space Station Freedom. The proposed control law was developed based on the direct adaptive control or model reference adaptive control scheme. Performance comparisons, subject to inertia variation, of the adaptive controller and the fixed-gain linear quadratic regulator currently implemented for the Space Station are conducted. Both the fixed-gain and the adaptive gain controllers are able to maintain the Station stability for inertia variations of up to 35 percent. However, when a 50 percent inertia variation is applied to the Station, only the adaptive controller is able to maintain the Station attitude.

  1. ISTAR: Intelligent System for Telemetry Analysis in Real-time

    NASA Technical Reports Server (NTRS)

    Simmons, Charles

    1994-01-01

    The intelligent system for telemetry analysis in real-time (ISTAR) is an advanced vehicle monitoring environment incorporating expert systems, analysis tools, and on-line hypermedia documentation. The system was developed for the Air Force Space and Missile Systems Center (SMC) in Los Angeles, California, in support of the inertial upper stage (IUS) booster vehicle. Over a five year period the system progressed from rapid prototype to operational system. ISTAR has been used to support five IUS missions and countless mission simulations. There were a significant number of lessons learned with respect to integrating an expert system capability into an existing ground system.

  2. Complex adaptive systems: A new approach for understanding health practices.

    PubMed

    Gomersall, Tim

    2018-06-22

    This article explores the potential of complex adaptive systems theory to inform behaviour change research. A complex adaptive system describes a collection of heterogeneous agents interacting within a particular context, adapting to each other's actions. In practical terms, this implies that behaviour change is 1) socially and culturally situated; 2) highly sensitive to small baseline differences in individuals, groups, and intervention components; and 3) determined by multiple components interacting "chaotically". Two approaches to studying complex adaptive systems are briefly reviewed. Agent-based modelling is a computer simulation technique that allows researchers to investigate "what if" questions in a virtual environment. Applied qualitative research techniques, on the other hand, offer a way to examine what happens when an intervention is pursued in real-time, and to identify the sorts of rules and assumptions governing social action. Although these represent very different approaches to complexity, there may be scope for mixing these methods - for example, by grounding models in insights derived from qualitative fieldwork. Finally, I will argue that the concept of complex adaptive systems offers one opportunity to gain a deepened understanding of health-related practices, and to examine the social psychological processes that produce health-promoting or damaging actions.

  3. Global adaptive control for uncertain nonaffine nonlinear hysteretic systems.

    PubMed

    Liu, Yong-Hua; Huang, Liangpei; Xiao, Dongming; Guo, Yong

    2015-09-01

    In this paper, the global output tracking is investigated for a class of uncertain nonlinear hysteretic systems with nonaffine structures. By combining the solution properties of the hysteresis model with the novel backstepping approach, a robust adaptive control algorithm is developed without constructing a hysteresis inverse. The proposed control scheme is further modified to tackle the bounded disturbances by adaptively estimating their bounds. It is rigorously proven that the designed adaptive controllers can guarantee global stability of the closed-loop system. Two numerical examples are provided to show the effectiveness of the proposed control schemes. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  4. Binocular Multispectral Adaptive Imaging System (BMAIS)

    DTIC Science & Technology

    2010-07-26

    system for pilots that adaptively integrates shortwave infrared (SWIR), visible, near ‐IR (NIR), off‐head thermal, and computer symbology/imagery into...respective areas. BMAIS is a binocular helmet mounted imaging system that features dual shortwave infrared (SWIR) cameras, embedded image processors and...algorithms and fusion of other sensor sites such as forward looking infrared (FLIR) and other aircraft subsystems. BMAIS is attached to the helmet

  5. Adaptable Miniature Initiation System Technology (AMIST)

    DTIC Science & Technology

    2006-09-01

    exploding foil initiator ( EFI ) to detonate an insensitive secondary explosive. The in-line (no moving parts) nature of EFIs increases their...reliability over out-of-line initiation systems. Likewise, EFI fire points increase the safety factor for two main reasons: (1) firing an EFI requires a very...AFRL-MN-EG-TP-2006-7410 ADAPTABLE MINIATURE INITIATION SYSTEM TECHNOLOGY (AMIST) Kenneth Bradley Chris Martin Ed Wild Air

  6. Management Strategies for Complex Adaptive Systems: Sensemaking, Learning, and Improvisation

    ERIC Educational Resources Information Center

    McDaniel, Reuben R., Jr.

    2007-01-01

    Misspecification of the nature of organizations may be a major reason for difficulty in achieving performance improvement. Organizations are often viewed as machine-like, but complexity science suggests that organizations should be viewed as complex adaptive systems. I identify the characteristics of complex adaptive systems and give examples of…

  7. Emergent “Quantum” Theory in Complex Adaptive Systems

    PubMed Central

    Minic, Djordje; Pajevic, Sinisa

    2017-01-01

    Motivated by the question of stability, in this letter we argue that an effective quantum-like theory can emerge in complex adaptive systems. In the concrete example of stochastic Lotka-Volterra dynamics, the relevant effective “Planck constant” associated with such emergent “quantum” theory has the dimensions of the square of the unit of time. Such an emergent quantum-like theory has inherently non-classical stability as well as coherent properties that are not, in principle, endangered by thermal fluctuations and therefore might be of crucial importance in complex adaptive systems. PMID:28890591

  8. Systems and Methods for Parameter Dependent Riccati Equation Approaches to Adaptive Control

    NASA Technical Reports Server (NTRS)

    Kim, Kilsoo (Inventor); Yucelen, Tansel (Inventor); Calise, Anthony J. (Inventor)

    2015-01-01

    Systems and methods for adaptive control are disclosed. The systems and methods can control uncertain dynamic systems. The control system can comprise a controller that employs a parameter dependent Riccati equation. The controller can produce a response that causes the state of the system to remain bounded. The control system can control both minimum phase and non-minimum phase systems. The control system can augment an existing, non-adaptive control design without modifying the gains employed in that design. The control system can also avoid the use of high gains in both the observer design and the adaptive control law.

  9. An adaptive control system for a shell-and-tube heat exchanger

    NASA Astrophysics Data System (ADS)

    Skorospeshkin, M. V.; Sukhodoev, M. S.; Skorospeshkin, V. N.; Rymashevskiy, P. O.

    2017-01-01

    This article suggests an adaptive control system for a hydrocarbon perspiration temperature control. This control system consists of a PI-controller and a pseudolinear compensating device that modifies control system dynamic properties. As a result, the behaviour research of the developed temperature control system has been undertaken. This article shows high effectiveness of the represented adaptive control system during changing control object parameters.

  10. Adaptive Neural Tracking Control for Switched High-Order Stochastic Nonlinear Systems.

    PubMed

    Zhao, Xudong; Wang, Xinyong; Zong, Guangdeng; Zheng, Xiaolong

    2017-10-01

    This paper deals with adaptive neural tracking control design for a class of switched high-order stochastic nonlinear systems with unknown uncertainties and arbitrary deterministic switching. The considered issues are: 1) completely unknown uncertainties; 2) stochastic disturbances; and 3) high-order nonstrict-feedback system structure. The considered mathematical models can represent many practical systems in the actual engineering. By adopting the approximation ability of neural networks, common stochastic Lyapunov function method together with adding an improved power integrator technique, an adaptive state feedback controller with multiple adaptive laws is systematically designed for the systems. Subsequently, a controller with only two adaptive laws is proposed to solve the problem of over parameterization. Under the designed controllers, all the signals in the closed-loop system are bounded-input bounded-output stable in probability, and the system output can almost surely track the target trajectory within a specified bounded error. Finally, simulation results are presented to show the effectiveness of the proposed approaches.

  11. Adaptive management of social-ecological systems: the path forward

    USGS Publications Warehouse

    Allen, Craig R.

    2015-01-01

    Adaptive management remains at the forefront of environmental management nearly 40 years after its original conception, largely because we have yet to develop other methodologies that offer the same promise. Despite the criticisms of adaptive management and the numerous failed attempts to implement it, adaptive management has yet to be replaced with a better alternative. The concept persists because it is simple, allows action despite uncertainty, and fosters learning. Moving forward, adaptive management of social-ecological systems provides policymakers, managers and scientists a powerful tool for managing for resilience in the face of uncertainty.

  12. Robust adaptive uniform exact tracking control for uncertain Euler-Lagrange system

    NASA Astrophysics Data System (ADS)

    Yang, Yana; Hua, Changchun; Li, Junpeng; Guan, Xinping

    2017-12-01

    This paper offers a solution to the robust adaptive uniform exact tracking control for uncertain nonlinear Euler-Lagrange (EL) system. An adaptive finite-time tracking control algorithm is designed by proposing a novel nonsingular integral terminal sliding-mode surface. Moreover, a new adaptive parameter tuning law is also developed by making good use of the system tracking errors and the adaptive parameter estimation errors. Thus, both the trajectory tracking and the parameter estimation can be achieved in a guaranteed time adjusted arbitrarily based on practical demands, simultaneously. Additionally, the control result for the EL system proposed in this paper can be extended to high-order nonlinear systems easily. Finally, a test-bed 2-DOF robot arm is set-up to demonstrate the performance of the new control algorithm.

  13. More pain, more gain: Blocking the opioid system boosts adaptive cognitive control.

    PubMed

    van Steenbergen, Henk; Weissman, Daniel H; Stein, Dan J; Malcolm-Smith, Susan; van Honk, Jack

    2017-06-01

    The ability to adaptively increase cognitive control in response to cognitive challenges is crucial for goal-directed behavior. Recent findings suggest that aversive arousal triggers adaptive increases of control, but the neurochemical mechanisms underlying these effects remain unclear. Given the known contributions of the opioid system to hedonic states, we investigated whether blocking this system increases adaptive control modulations. To do so, we conducted a double-blind, placebo-controlled psychopharmacological study (n=52 females) involving a Stroop-like task. Specifically, we assessed the effect of naltrexone, an opioid blocker most selective to the mu-opioid system, on two measures of adaptive control that are thought to depend differentially on aversive arousal: post-error slowing and conflict adaptation. Consistent with our hypothesis, relative to placebo, naltrexone increased post-error slowing without influencing conflict adaptation. This finding not only supports the view that aversive arousal triggers adaptive control but also reveals a novel role for the opioid system in modulating such effects. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Human adaptive immune system Rag2-/-gamma(c)-/- mice.

    PubMed

    Chicha, Laurie; Tussiwand, Roxane; Traggiai, Elisabetta; Mazzucchelli, Luca; Bronz, Lucio; Piffaretti, Jean-Claude; Lanzavecchia, Antonio; Manz, Markus G

    2005-06-01

    Although many biologic principles are conserved in mice and humans, species-specific differences exist, for example, in susceptibility and response to pathogens, that often do not allow direct implementation of findings in experimental mice to humans. Research in humans, however, for ethical and practical reasons, is largely restricted to in vitro assays that lack components and the complexity of a living organism. To nevertheless study the human hematopoietic and immune system in vivo, xenotransplantation assays have been developed that substitute human components to small animals. Here, we summarize our recent findings that transplantation of human cord blood CD34(+) cells to newborn Rag2(-/-)gamma(c)(-/-) mice leads to de novo development of major functional components of the human adaptive immune system. These human adaptive immune system Rag2(-/-)gamma(c)(-/-) (huAIS-RG) mice can now be used as a technically straightforward preclinical model to evaluate in vivo human adaptive immune system development as well as immune responses, for example, to vaccines or live infectious pathogens.

  15. Systems integration of innate and adaptive immunity.

    PubMed

    Zak, Daniel E; Aderem, Alan

    2015-09-29

    The pathogens causing AIDS, malaria, and tuberculosis have proven too complex to be overcome by classical approaches to vaccination. The complexities of human immunology and pathogen-induced modulation of the immune system mandate new approaches to vaccine discovery and design. A new field, systems vaccinology, weds holistic analysis of innate and adaptive immunity within a quantitative framework to enable rational design of new vaccines that elicit tailored protective immune responses. A key step in the approach is to discover relationships between the earliest innate inflammatory responses to vaccination and the subsequent vaccine-induced adaptive immune responses and efficacy. Analysis of these responses in clinical studies is complicated by the inaccessibility of relevant tissue compartments (such as the lymph node), necessitating reliance upon peripheral blood responses as surrogates. Blood transcriptomes, although indirect to vaccine mechanisms, have proven very informative in systems vaccinology studies. The approach is most powerful when innate and adaptive immune responses are integrated with vaccine efficacy, which is possible for malaria with the advent of a robust human challenge model. This is more difficult for AIDS and tuberculosis, given that human challenge models are lacking and efficacy observed in clinical trials has been low or highly variable. This challenge can be met by appropriate clinical trial design for partially efficacious vaccines and by analysis of natural infection cohorts. Ultimately, systems vaccinology is an iterative approach in which mechanistic hypotheses-derived from analysis of clinical studies-are evaluated in model systems, and then used to guide the development of new vaccine strategies. In this review, we will illustrate the above facets of the systems vaccinology approach with case studies. Copyright © 2015. Published by Elsevier Ltd.

  16. Computerized Adaptive Testing System Design: Preliminary Design Considerations.

    ERIC Educational Resources Information Center

    Croll, Paul R.

    A functional design model for a computerized adaptive testing (CAT) system was developed and presented through a series of hierarchy plus input-process-output (HIPO) diagrams. System functions were translated into system structure: specifically, into 34 software components. Implementation of the design in a physical system was addressed through…

  17. Substantiation of Structure of Adaptive Control Systems for Motor Units

    NASA Astrophysics Data System (ADS)

    Ovsyannikov, S. I.

    2018-05-01

    The article describes the development of new electronic control systems, in particular motor units, for small-sized agricultural equipment. Based on the analysis of traffic control systems, the main course of development of the conceptual designs of motor units has been defined. The systems aimed to control the course motion of the motor unit in automatic mode using the adaptive systems have been developed. The article presents structural models of the conceptual motor units based on electrically controlled systems by the operation of drive motors and adaptive systems that make the motor units completely automated.

  18. Complex adaptive systems and their relevance for nursing: An evolutionary concept analysis.

    PubMed

    Notarnicola, Ippolito; Petrucci, Cristina; De Jesus Barbosa, Maria Rosimar; Giorgi, Fabio; Stievano, Alessandro; Rocco, Gennaro; Lancia, Loreto

    2017-06-01

    This study aimed to analyse the concept of "complex adaptive systems." The construct is still nebulous in the literature, and a further explanation of the idea is needed to have a shared knowledge of it. A concept analysis was conducted utilizing Rodgers evolutionary method. The inclusive years of bibliographic search started from 2005 to 2015. The search was conducted at PubMed©, CINAHL© (EBSCO host©), Scopus©, Web of Science©, and Academic Search Premier©. Retrieved papers were critically analysed to explore the attributes, antecedents, and consequences of the concept. Moreover, surrogates, related terms, and a pattern recognition scheme were identified. The concept analysis showed that complex systems are adaptive and have the ability to process information. They can adapt to the environment and consequently evolve. Nursing is a complex adaptive system, and the nursing profession in practice exhibits complex adaptive system characteristics. Complexity science through complex adaptive systems provides new ways of seeing and understanding the mechanisms that underpin the nursing profession. © 2017 John Wiley & Sons Australia, Ltd.

  19. Adaptive Optical System for Retina Imaging Approaches Clinic Applications

    NASA Astrophysics Data System (ADS)

    Ling, N.; Zhang, Y.; Rao, X.; Wang, C.; Hu, Y.; Jiang, W.; Jiang, C.

    We presented "A small adaptive optical system on table for human retinal imaging" at the 3rd Workshop on Adaptive Optics for Industry and Medicine. In this system, a 19 element small deformable mirror was used as wavefront correction element. High resolution images of photo receptors and capillaries of human retina were obtained. In recent two years, at the base of this system a new adaptive optical system for human retina imaging has been developed. The wavefront correction element is a newly developed 37 element deformable mirror. Some modifications have been adopted for easy operation. Experiments for different imaging wavelengths and axial positions were conducted. Mosaic pictures of photoreceptors and capillaries were obtained. 100 normal and abnormal eyes of different ages have been inspected.The first report in the world concerning the most detailed capillary distribution images cover ±3° by ± 3° field around the fovea has been demonstrated. Some preliminary very early diagnosis experiment has been tried in laboratory. This system is being planned to move to the hospital for clinic experiments.

  20. Adaptive receiver structures for asynchronous CDMA systems

    NASA Astrophysics Data System (ADS)

    Rapajic, Predrag B.; Vucetic, Branka S.

    1994-05-01

    Adaptive linear and decision feedback receiver structures for coherent demodulation in asynchronous code division multiple access (CDMA) systems are considered. It is assumed that the adaptive receiver has no knowledge of the signature waveforms and timing of other users. The receiver is trained by a known training sequence prior to data transmission and continuously adjusted by an adaptive algorithm during data transmission. The proposed linear receiver is as simple as a standard single-user detector receiver consisting of a matched filter with constant coefficients, but achieves essential advantages with respect to timing recovery, multiple access interference elimination, near/far effect, narrowband and frequency-selective fading interference suppression, and user privacy. An adaptive centralized decision feedback receiver has the same advantages of the linear receiver but, in addition, achieves a further improvement in multiple access interference cancellation at the expense of higher complexity. The proposed receiver structures are tested by simulation over a channel with multipath propagation, multiple access interference, narrowband interference, and additive white Gaussian noise.

  1. Adaptive optics system application for solar telescope

    NASA Astrophysics Data System (ADS)

    Lukin, V. P.; Grigor'ev, V. M.; Antoshkin, L. V.; Botugina, N. N.; Emaleev, O. N.; Konyaev, P. A.; Kovadlo, P. G.; Krivolutskiy, N. P.; Lavrionova, L. N.; Skomorovski, V. I.

    2008-07-01

    The possibility of applying adaptive correction to ground-based solar astronomy is considered. Several experimental systems for image stabilization are described along with the results of their tests. Using our work along several years and world experience in solar adaptive optics (AO) we are assuming to obtain first light to the end of 2008 for the first Russian low order ANGARA solar AO system on the Big Solar Vacuum Telescope (BSVT) with 37 subapertures Shack-Hartmann wavefront sensor based of our modified correlation tracker algorithm, DALSTAR video camera, 37 elements deformable bimorph mirror, home made fast tip-tip mirror with separate correlation tracker. Too strong daytime turbulence is on the BSVT site and we are planning to obtain a partial correction for part of Sun surface image.

  2. Constructing Interpretative Views of Learners' Interaction Behavior in an Open Learner Model

    ERIC Educational Resources Information Center

    Papanikolaou, Kyparisia A.

    2015-01-01

    In this paper, we discuss how externalizing learners' interaction behavior may support learners' explorations in an adaptive educational hypermedia environment that provides activity-oriented content. In particular, we propose a model for producing interpretative views of learners' interaction behavior and we further apply this model to…

  3. Towards Contextualized Learning Services

    NASA Astrophysics Data System (ADS)

    Specht, Marcus

    Personalization of feedback and instruction has often been considered as a key feature in learning support. The adaptations of the instructional process to the individual and its different aspects have been investigated from different research perspectives as learner modelling, intelligent tutoring systems, adaptive hypermedia, adaptive instruction and others. Already in the 1950s first commercial systems for adaptive instruction for trainings of keyboard skills have been developed utilizing adaptive configuration of feedback based on user performance and interaction footprints (Pask 1964). Around adaptive instruction there is a variety of research issues bringing together interdisciplinary research from computer science, engineering, psychology, psychotherapy, cybernetics, system dynamics, instructional design, and empirical research on technology enhanced learning. When classifying best practices of adaptive instruction different parameters of the instructional process have been identified which are adapted to the learner, as: sequence and size of task difficulty, time of feedback, pace of learning speed, reinforcement plan and others these are often referred to the adaptation target. Furthermore Aptitude Treatment Interaction studies explored the effect of adapting instructional parameters to different characteristics of the learner (Tennyson and Christensen 1988) as task performance, personality characteristics, or cognitive abilities, this is information is referred to as adaptation mean.

  4. Modeling Power Systems as Complex Adaptive Systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chassin, David P.; Malard, Joel M.; Posse, Christian

    2004-12-30

    Physical analogs have shown considerable promise for understanding the behavior of complex adaptive systems, including macroeconomics, biological systems, social networks, and electric power markets. Many of today's most challenging technical and policy questions can be reduced to a distributed economic control problem. Indeed, economically based control of large-scale systems is founded on the conjecture that the price-based regulation (e.g., auctions, markets) results in an optimal allocation of resources and emergent optimal system control. This report explores the state-of-the-art physical analogs for understanding the behavior of some econophysical systems and deriving stable and robust control strategies for using them. We reviewmore » and discuss applications of some analytic methods based on a thermodynamic metaphor, according to which the interplay between system entropy and conservation laws gives rise to intuitive and governing global properties of complex systems that cannot be otherwise understood. We apply these methods to the question of how power markets can be expected to behave under a variety of conditions.« less

  5. Evolving Systems and Adaptive Key Component Control

    NASA Technical Reports Server (NTRS)

    Frost, Susan A.; Balas, Mark J.

    2009-01-01

    We propose a new framework called Evolving Systems to describe the self-assembly, or autonomous assembly, of actively controlled dynamical subsystems into an Evolved System with a higher purpose. An introduction to Evolving Systems and exploration of the essential topics of the control and stability properties of Evolving Systems is provided. This chapter defines a framework for Evolving Systems, develops theory and control solutions for fundamental characteristics of Evolving Systems, and provides illustrative examples of Evolving Systems and their control with adaptive key component controllers.

  6. Adaptive Modeling of the International Space Station Electrical Power System

    NASA Technical Reports Server (NTRS)

    Thomas, Justin Ray

    2007-01-01

    Software simulations provide NASA engineers the ability to experiment with spacecraft systems in a computer-imitated environment. Engineers currently develop software models that encapsulate spacecraft system behavior. These models can be inaccurate due to invalid assumptions, erroneous operation, or system evolution. Increasing accuracy requires manual calibration and domain-specific knowledge. This thesis presents a method for automatically learning system models without any assumptions regarding system behavior. Data stream mining techniques are applied to learn models for critical portions of the International Space Station (ISS) Electrical Power System (EPS). We also explore a knowledge fusion approach that uses traditional engineered EPS models to supplement the learned models. We observed that these engineered EPS models provide useful background knowledge to reduce predictive error spikes when confronted with making predictions in situations that are quite different from the training scenarios used when learning the model. Evaluations using ISS sensor data and existing EPS models demonstrate the success of the adaptive approach. Our experimental results show that adaptive modeling provides reductions in model error anywhere from 80% to 96% over these existing models. Final discussions include impending use of adaptive modeling technology for ISS mission operations and the need for adaptive modeling in future NASA lunar and Martian exploration.

  7. Optimal Control Modification for Robust Adaptation of Singularly Perturbed Systems with Slow Actuators

    NASA Technical Reports Server (NTRS)

    Nguyen, Nhan T.; Ishihara, Abraham; Stepanyan, Vahram; Boskovic, Jovan

    2009-01-01

    Recently a new optimal control modification has been introduced that can achieve robust adaptation with a large adaptive gain without incurring high-frequency oscillations as with the standard model-reference adaptive control. This modification is based on an optimal control formulation to minimize the L2 norm of the tracking error. The optimal control modification adaptive law results in a stable adaptation in the presence of a large adaptive gain. This study examines the optimal control modification adaptive law in the context of a system with a time scale separation resulting from a fast plant with a slow actuator. A singular perturbation analysis is performed to derive a modification to the adaptive law by transforming the original system into a reduced-order system in slow time. The model matching conditions in the transformed time coordinate results in increase in the feedback gain and modification of the adaptive law.

  8. An architecture for rule based system explanation

    NASA Technical Reports Server (NTRS)

    Fennel, T. R.; Johannes, James D.

    1990-01-01

    A system architecture is presented which incorporate both graphics and text into explanations provided by rule based expert systems. This architecture facilitates explanation of the knowledge base content, the control strategies employed by the system, and the conclusions made by the system. The suggested approach combines hypermedia and inference engine capabilities. Advantages include: closer integration of user interface, explanation system, and knowledge base; the ability to embed links to deeper knowledge underlying the compiled knowledge used in the knowledge base; and allowing for more direct control of explanation depth and duration by the user. User models are suggested to control the type, amount, and order of information presented.

  9. Nanosatellite Launch Adapter System (NLAS)

    NASA Technical Reports Server (NTRS)

    Chartres, James; Cappuccio, Gelsomina

    2015-01-01

    The Nanosatellite Launch Adapter System (NLAS) was developed to increase access to space while simplifying the integration process of miniature satellites, called nanosats or CubeSats, onto launch vehicles. A standard CubeSat measures about 10 cm square, and is referred to as a 1-unit (1U) CubeSat. A single NLAS provides the capability to deploy 24U of CubeSats. The system is designed to accommodate satellites measuring 1U, 1.5U, 2U, 3U and 6U sizes for deployment into orbit. The NLAS may be configured for use on different launch vehicles. The system also enables flight demonstrations of new technologies in the space environment.

  10. An adaptive optics system for solid-state laser systems used in inertial confinement fusion

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Salmon, J.T.; Bliss, E.S.; Byrd, J.L.

    1995-09-17

    Using adaptive optics the authors have obtained nearly diffraction-limited 5 kJ, 3 nsec output pulses at 1.053 {micro}m from the Beamlet demonstration system for the National Ignition Facility (NIF). The peak Strehl ratio was improved from 0.009 to 0.50, as estimated from measured wavefront errors. They have also measured the relaxation of the thermally induced aberrations in the main beam line over a period of 4.5 hours. Peak-to-valley aberrations range from 6.8 waves at 1.053 {micro}m within 30 minutes after a full system shot to 3.9 waves after 4.5 hours. The adaptive optics system must have enough range to correctmore » accumulated thermal aberrations from several shots in addition to the immediate shot-induced error. Accumulated wavefront errors in the beam line will affect both the design of the adaptive optics system for NIF and the performance of that system.« less

  11. SDR implementation of the receiver of adaptive communication system

    NASA Astrophysics Data System (ADS)

    Skarzynski, Jacek; Darmetko, Marcin; Kozlowski, Sebastian; Kurek, Krzysztof

    2016-04-01

    The paper presents software implementation of a receiver forming a part of an adaptive communication system. The system is intended for communication with a satellite placed in a low Earth orbit (LEO). The ability of adaptation is believed to increase the total amount of data transmitted from the satellite to the ground station. Depending on the signal-to-noise ratio (SNR) of the received signal, adaptive transmission is realized using different transmission modes, i.e., different modulation schemes (BPSK, QPSK, 8-PSK, and 16-APSK) and different convolutional code rates (1/2, 2/3, 3/4, 5/6, and 7/8). The receiver consists of a software-defined radio (SDR) module (National Instruments USRP-2920) and a multithread reception software running on Windows operating system. In order to increase the speed of signal processing, the software takes advantage of single instruction multiple data instructions supported by x86 processor architecture.

  12. Adaptive integral robust control and application to electromechanical servo systems.

    PubMed

    Deng, Wenxiang; Yao, Jianyong

    2017-03-01

    This paper proposes a continuous adaptive integral robust control with robust integral of the sign of the error (RISE) feedback for a class of uncertain nonlinear systems, in which the RISE feedback gain is adapted online to ensure the robustness against disturbances without the prior bound knowledge of the additive disturbances. In addition, an adaptive compensation integrated with the proposed adaptive RISE feedback term is also constructed to further reduce design conservatism when the system also exists parametric uncertainties. Lyapunov analysis reveals the proposed controllers could guarantee the tracking errors are asymptotically converging to zero with continuous control efforts. To illustrate the high performance nature of the developed controllers, numerical simulations are provided. At the end, an application case of an actual electromechanical servo system driven by motor is also studied, with some specific design consideration, and comparative experimental results are obtained to verify the effectiveness of the proposed controllers. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  13. Evaluation Framework Based on Fuzzy Measured Method in Adaptive Learning Systems

    ERIC Educational Resources Information Center

    Ounaies, Houda Zouari; Jamoussi, Yassine; Ben Ghezala, Henda Hajjami

    2008-01-01

    Currently, e-learning systems are mainly web-based applications and tackle a wide range of users all over the world. Fitting learners' needs is considered as a key issue to guaranty the success of these systems. Many researches work on providing adaptive systems. Nevertheless, evaluation of the adaptivity is still in an exploratory phase.…

  14. Digital adaptive optics line-scanning confocal imaging system.

    PubMed

    Liu, Changgeng; Kim, Myung K

    2015-01-01

    A digital adaptive optics line-scanning confocal imaging (DAOLCI) system is proposed by applying digital holographic adaptive optics to a digital form of line-scanning confocal imaging system. In DAOLCI, each line scan is recorded by a digital hologram, which allows access to the complex optical field from one slice of the sample through digital holography. This complex optical field contains both the information of one slice of the sample and the optical aberration of the system, thus allowing us to compensate for the effect of the optical aberration, which can be sensed by a complex guide star hologram. After numerical aberration compensation, the corrected optical fields of a sequence of line scans are stitched into the final corrected confocal image. In DAOLCI, a numerical slit is applied to realize the confocality at the sensor end. The width of this slit can be adjusted to control the image contrast and speckle noise for scattering samples. DAOLCI dispenses with the hardware pieces, such as Shack–Hartmann wavefront sensor and deformable mirror, and the closed-loop feedbacks adopted in the conventional adaptive optics confocal imaging system, thus reducing the optomechanical complexity and cost. Numerical simulations and proof-of-principle experiments are presented that demonstrate the feasibility of this idea.

  15. Adaptive simplification of complex multiscale systems.

    PubMed

    Chiavazzo, Eliodoro; Karlin, Ilya

    2011-03-01

    A fully adaptive methodology is developed for reducing the complexity of large dissipative systems. This represents a significant step toward extracting essential physical knowledge from complex systems, by addressing the challenging problem of a minimal number of variables needed to exactly capture the system dynamics. Accurate reduced description is achieved, by construction of a hierarchy of slow invariant manifolds, with an embarrassingly simple implementation in any dimension. The method is validated with the autoignition of the hydrogen-air mixture where a reduction to a cascade of slow invariant manifolds is observed.

  16. Adaptive Identification of Fluid-Dynamic Systems

    DTIC Science & Technology

    2001-06-14

    Fig. 1. Unknown System Adaptive Filter Σ _ + Input u Filter Output y Desired Output d Error e Fig. 1. Modeling of a SISO system using...2J E e n =   (12) Here [ ]. E is the expectation operator and ( ) ( ) ( ) e n d n y n= − is the error between the desired system output and...B … input vector ( ) ( ) ( ) ( )[ ], , ,1 1 Tn u n u n u n N= − − +U … output and error ( ) ( ) ( ) ( ) ( ) ( ) ( ) T T y n n n e n d n n n

  17. 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

  18. Homeostatic Regulation of Memory Systems and Adaptive Decisions

    PubMed Central

    Mizumori, Sheri JY; Jo, Yong Sang

    2013-01-01

    While it is clear that many brain areas process mnemonic information, understanding how their interactions result in continuously adaptive behaviors has been a challenge. A homeostatic-regulated prediction model of memory is presented that considers the existence of a single memory system that is based on a multilevel coordinated and integrated network (from cells to neural systems) that determines the extent to which events and outcomes occur as predicted. The “multiple memory systems of the brain” have in common output that signals errors in the prediction of events and/or their outcomes, although these signals differ in terms of what the error signal represents (e.g., hippocampus: context prediction errors vs. midbrain/striatum: reward prediction errors). The prefrontal cortex likely plays a pivotal role in the coordination of prediction analysis within and across prediction brain areas. By virtue of its widespread control and influence, and intrinsic working memory mechanisms. Thus, the prefrontal cortex supports the flexible processing needed to generate adaptive behaviors and predict future outcomes. It is proposed that prefrontal cortex continually and automatically produces adaptive responses according to homeostatic regulatory principles: prefrontal cortex may serve as a controller that is intrinsically driven to maintain in prediction areas an experience-dependent firing rate set point that ensures adaptive temporally and spatially resolved neural responses to future prediction errors. This same drive by prefrontal cortex may also restore set point firing rates after deviations (i.e. prediction errors) are detected. In this way, prefrontal cortex contributes to reducing uncertainty in prediction systems. An emergent outcome of this homeostatic view may be the flexible and adaptive control that prefrontal cortex is known to implement (i.e. working memory) in the most challenging of situations. Compromise to any of the prediction circuits should result

  19. Homeostatic regulation of memory systems and adaptive decisions.

    PubMed

    Mizumori, Sheri J Y; Jo, Yong Sang

    2013-11-01

    While it is clear that many brain areas process mnemonic information, understanding how their interactions result in continuously adaptive behaviors has been a challenge. A homeostatic-regulated prediction model of memory is presented that considers the existence of a single memory system that is based on a multilevel coordinated and integrated network (from cells to neural systems) that determines the extent to which events and outcomes occur as predicted. The "multiple memory systems of the brain" have in common output that signals errors in the prediction of events and/or their outcomes, although these signals differ in terms of what the error signal represents (e.g., hippocampus: context prediction errors vs. midbrain/striatum: reward prediction errors). The prefrontal cortex likely plays a pivotal role in the coordination of prediction analysis within and across prediction brain areas. By virtue of its widespread control and influence, and intrinsic working memory mechanisms. Thus, the prefrontal cortex supports the flexible processing needed to generate adaptive behaviors and predict future outcomes. It is proposed that prefrontal cortex continually and automatically produces adaptive responses according to homeostatic regulatory principles: prefrontal cortex may serve as a controller that is intrinsically driven to maintain in prediction areas an experience-dependent firing rate set point that ensures adaptive temporally and spatially resolved neural responses to future prediction errors. This same drive by prefrontal cortex may also restore set point firing rates after deviations (i.e. prediction errors) are detected. In this way, prefrontal cortex contributes to reducing uncertainty in prediction systems. An emergent outcome of this homeostatic view may be the flexible and adaptive control that prefrontal cortex is known to implement (i.e. working memory) in the most challenging of situations. Compromise to any of the prediction circuits should result in

  20. Adaptive Optics Imaging of Solar System Objects

    NASA Technical Reports Server (NTRS)

    Roddier, Francois; Owen, Toby

    1999-01-01

    Most solar system objects have never been observed at wavelengths longer than the R band with an angular resolution better than 1". The Hubble Space Telescope itself has only recently been equipped to observe in the infrared. However, because of its small diameter, the angular resolution is lower than that one can now achieved from the ground with adaptive optics, and time allocated to planetary science is limited. We have successfully used adaptive optics on a 4-m class telescope to obtain 0.1" resolution images of solar system objects in the far red and near infrared (0.7-2.5 microns), aE wavelengths which best discl"lmlnate their spectral signatures. Our efforts have been put into areas of research for which high angular resolution is essential.

  1. Organization of an optimal adaptive immune system

    NASA Astrophysics Data System (ADS)

    Walczak, Aleksandra; Mayer, Andreas; Balasubramanian, Vijay; Mora, Thierry

    The repertoire of lymphocyte receptors in the adaptive immune system protects organisms from a diverse set of pathogens. A well-adapted repertoire should be tuned to the pathogenic environment to reduce the cost of infections. I will discuss a general framework for predicting the optimal repertoire that minimizes the cost of infections contracted from a given distribution of pathogens. The theory predicts that the immune system will have more receptors for rare antigens than expected from the frequency of encounters and individuals exposed to the same infections will have sparse repertoires that are largely different, but nevertheless exploit cross-reactivity to provide the same coverage of antigens. I will show that the optimal repertoires can be reached by dynamics that describes the competitive binding of antigens by receptors, and selective amplification of stimulated receptors.

  2. Generating Shifting Workloads to Benchmark Adaptability in Relational Database Systems

    NASA Astrophysics Data System (ADS)

    Rabl, Tilmann; Lang, Andreas; Hackl, Thomas; Sick, Bernhard; Kosch, Harald

    A large body of research concerns the adaptability of database systems. Many commercial systems already contain autonomic processes that adapt configurations as well as data structures and data organization. Yet there is virtually no possibility for a just measurement of the quality of such optimizations. While standard benchmarks have been developed that simulate real-world database applications very precisely, none of them considers variations in workloads produced by human factors. Today’s benchmarks test the performance of database systems by measuring peak performance on homogeneous request streams. Nevertheless, in systems with user interaction access patterns are constantly shifting. We present a benchmark that simulates a web information system with interaction of large user groups. It is based on the analysis of a real online eLearning management system with 15,000 users. The benchmark considers the temporal dependency of user interaction. Main focus is to measure the adaptability of a database management system according to shifting workloads. We will give details on our design approach that uses sophisticated pattern analysis and data mining techniques.

  3. Adaptable Transponder for Multiple Telemetry Systems

    NASA Technical Reports Server (NTRS)

    Sims, William Herbert, III (Inventor); Varnavas, Kosta A. (Inventor)

    2014-01-01

    The present invention is a stackable telemetry circuit board for use in telemetry systems for satellites and other purposes. The present invention incorporates previously-qualified interchangeable circuit boards, or "decks," that perform functions such as power, signal receiving and transmission, and processing. Each deck is adapted to serve a range of telemetry applications. This provides flexibility in the construction of the stackable telemetry circuit board and significantly reduces the cost and time necessary to develop a telemetry system.

  4. Coupling between Metacognition and Emotions during STEM Learning with Advanced Learning Technologies: A Critical Analysis, Implications for Future Research, and Design of Learning Systems

    ERIC Educational Resources Information Center

    Azevedo, Roger; Mudrick, Nicholas; Taub, Michelle; Wortha, Franz

    2017-01-01

    Metacognition and emotions play a critical role in learners' ability to monitor and regulate their learning about 21st-century skills related to science, technology, engineering, and mathematics (STEM) content while using advanced learning technologies (ALTs; e.g., intelligent tutoring systems, serious games, hypermedia, augmented reality). In…

  5. Integrated System Design: Promoting the Capacity of Sociotechnical Systems for Adaptation through Extensions of Cognitive Work Analysis

    PubMed Central

    Naikar, Neelam; Elix, Ben

    2016-01-01

    This paper proposes an approach for integrated system design, which has the intent of facilitating high levels of effectiveness in sociotechnical systems by promoting their capacity for adaptation. Building on earlier ideas and empirical observations, this approach recognizes that to create adaptive systems it is necessary to integrate the design of all of the system elements, including the interfaces, teams, training, and automation, such that workers are supported in adapting their behavior as well as their structure, or organization, in a coherent manner. Current approaches for work analysis and design are limited in regard to this fundamental objective, especially in cases when workers are confronted with unforeseen events. A suitable starting point is offered by cognitive work analysis (CWA), but while this framework can support actors in adapting their behavior, it does not necessarily accommodate adaptations in their structure. Moreover, associated design approaches generally focus on individual system elements, and those that consider multiple elements appear limited in their ability to facilitate integration, especially in the manner intended here. The proposed approach puts forward the set of possibilities for work organization in a system as the central mechanism for binding the design of its various elements, so that actors can adapt their structure as well as their behavior—in a unified fashion—to handle both familiar and novel conditions. Accordingly, this paper demonstrates how the set of possibilities for work organization in a system may be demarcated independently of the situation, through extensions of CWA, and how it may be utilized in design. This lynchpin, conceptualized in the form of a diagram of work organization possibilities (WOP), is important for preserving a system's inherent capacity for adaptation. Future research should focus on validating these concepts and establishing the feasibility of implementing them in industrial

  6. Integrated System Design: Promoting the Capacity of Sociotechnical Systems for Adaptation through Extensions of Cognitive Work Analysis.

    PubMed

    Naikar, Neelam; Elix, Ben

    2016-01-01

    This paper proposes an approach for integrated system design, which has the intent of facilitating high levels of effectiveness in sociotechnical systems by promoting their capacity for adaptation. Building on earlier ideas and empirical observations, this approach recognizes that to create adaptive systems it is necessary to integrate the design of all of the system elements, including the interfaces, teams, training, and automation, such that workers are supported in adapting their behavior as well as their structure, or organization, in a coherent manner. Current approaches for work analysis and design are limited in regard to this fundamental objective, especially in cases when workers are confronted with unforeseen events. A suitable starting point is offered by cognitive work analysis (CWA), but while this framework can support actors in adapting their behavior, it does not necessarily accommodate adaptations in their structure. Moreover, associated design approaches generally focus on individual system elements, and those that consider multiple elements appear limited in their ability to facilitate integration, especially in the manner intended here. The proposed approach puts forward the set of possibilities for work organization in a system as the central mechanism for binding the design of its various elements, so that actors can adapt their structure as well as their behavior-in a unified fashion-to handle both familiar and novel conditions. Accordingly, this paper demonstrates how the set of possibilities for work organization in a system may be demarcated independently of the situation, through extensions of CWA, and how it may be utilized in design. This lynchpin, conceptualized in the form of a diagram of work organization possibilities (WOP), is important for preserving a system's inherent capacity for adaptation. Future research should focus on validating these concepts and establishing the feasibility of implementing them in industrial contexts.

  7. Study of application of adaptive systems to the exploration of the solar system. Volume 1: Summary

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The field of artificial intelligence to identify practical applications to unmanned spacecraft used to explore the solar system in the decade of the 80s is examined. If an unmanned spacecraft can be made to adjust or adapt to the environment, to make decisions about what it measures and how it uses and reports the data, it can become a much more powerful tool for the science community in unlocking the secrets of the solar system. Within this definition of an adaptive spacecraft or system, there is a broad range of variability. In terms of sophistication, an adaptive system can be extremely simple or as complex as a chess-playing machine that learns from its mistakes.

  8. Adaptive Management of Computing and Network Resources for Spacecraft Systems

    NASA Technical Reports Server (NTRS)

    Pfarr, Barbara; Welch, Lonnie R.; Detter, Ryan; Tjaden, Brett; Huh, Eui-Nam; Szczur, Martha R. (Technical Monitor)

    2000-01-01

    It is likely that NASA's future spacecraft systems will consist of distributed processes which will handle dynamically varying workloads in response to perceived scientific events, the spacecraft environment, spacecraft anomalies and user commands. Since all situations and possible uses of sensors cannot be anticipated during pre-deployment phases, an approach for dynamically adapting the allocation of distributed computational and communication resources is needed. To address this, we are evolving the DeSiDeRaTa adaptive resource management approach to enable reconfigurable ground and space information systems. The DeSiDeRaTa approach embodies a set of middleware mechanisms for adapting resource allocations, and a framework for reasoning about the real-time performance of distributed application systems. The framework and middleware will be extended to accommodate (1) the dynamic aspects of intra-constellation network topologies, and (2) the complete real-time path from the instrument to the user. We are developing a ground-based testbed that will enable NASA to perform early evaluation of adaptive resource management techniques without the expense of first deploying them in space. The benefits of the proposed effort are numerous, including the ability to use sensors in new ways not anticipated at design time; the production of information technology that ties the sensor web together; the accommodation of greater numbers of missions with fewer resources; and the opportunity to leverage the DeSiDeRaTa project's expertise, infrastructure and models for adaptive resource management for distributed real-time systems.

  9. Systematic, Multimethod Assessment of Adaptations Across Four Diverse Health Systems Interventions.

    PubMed

    Rabin, Borsika A; McCreight, Marina; Battaglia, Catherine; Ayele, Roman; Burke, Robert E; Hess, Paul L; Frank, Joseph W; Glasgow, Russell E

    2018-01-01

    Many health outcomes and implementation science studies have demonstrated the importance of tailoring evidence-based care interventions to local context to improve fit. By adapting to local culture, history, resources, characteristics, and priorities, interventions are more likely to lead to improved outcomes. However, it is unclear how best to adapt evidence-based programs and promising innovations. There are few guides or examples of how to best categorize or assess health-care adaptations, and even fewer that are brief and practical for use by non-researchers. This study describes the importance and potential of assessing adaptations before, during, and after the implementation of health systems interventions. We present a promising multilevel and multimethod approach developed and being applied across four different health systems interventions. Finally, we discuss implications and opportunities for future research. The four case studies are diverse in the conditions addressed, interventions, and implementation strategies. They include two nurse coordinator-based transition of care interventions, a data and training-driven multimodal pain management project, and a cardiovascular patient-reported outcomes project, all of which are using audit and feedback. We used the same modified adaptation framework to document changes made to the interventions and implementation strategies. To create the modified framework, we started with the adaptation and modification model developed by Stirman and colleagues and expanded it by adding concepts from the RE-AIM framework. Our assessments address the intuitive domains of Who, How, When, What, and Why to classify and organize adaptations. For each case study, we discuss how the modified framework was operationalized, the multiple methods used to collect data, results to date and approaches utilized for data analysis. These methods include a real-time tracking system and structured interviews at key times during the

  10. Observer-Based Adaptive Fault-Tolerant Tracking Control of Nonlinear Nonstrict-Feedback Systems.

    PubMed

    Wu, Chengwei; Liu, Jianxing; Xiong, Yongyang; Wu, Ligang

    2017-06-28

    This paper studies an output-based adaptive fault-tolerant control problem for nonlinear systems with nonstrict-feedback form. Neural networks are utilized to identify the unknown nonlinear characteristics in the system. An observer and a general fault model are constructed to estimate the unavailable states and describe the fault, respectively. Adaptive parameters are constructed to overcome the difficulties in the design process for nonstrict-feedback systems. Meanwhile, dynamic surface control technique is introduced to avoid the problem of ''explosion of complexity''. Furthermore, based on adaptive backstepping control method, an output-based adaptive neural tracking control strategy is developed for the considered system against actuator fault, which can ensure that all the signals in the resulting closed-loop system are bounded, and the system output signal can be regulated to follow the response of the given reference signal with a small error. Finally, the simulation results are provided to validate the effectiveness of the control strategy proposed in this paper.

  11. A sequential adaptation technique and its application to the Mark 12 IFF system

    NASA Astrophysics Data System (ADS)

    Bailey, John S.; Mallett, John D.; Sheppard, Duane J.; Warner, F. Neal; Adams, Robert

    1986-07-01

    Sequential adaptation uses only two sets of receivers, correlators, and A/D converters which are time multiplexed to effect spatial adaptation in a system with (N) adaptive degrees of freedom. This technique can substantially reduce the hardware cost over what is realizable in a parallel architecture. A three channel L-band version of the sequential adapter was built and tested for use with the MARK XII IFF (identify friend or foe) system. In this system the sequentially determined adaptive weights were obtained digitally but implemented at RF. As a result, many of the post RF hardware induced sources of error that normally limit cancellation, such as receiver mismatch, are removed by the feedback property. The result is a system that can yield high levels of cancellation and be readily retrofitted to currently fielded equipment.

  12. An Adaptive Scaffolding E-Learning System for Middle School Students' Physics Learning

    ERIC Educational Resources Information Center

    Chen, Ching-Huei

    2014-01-01

    This study presents a framework that utilizes cognitive and motivational aspects of learning to design an adaptive scaffolding e-learning system. It addresses scaffolding processes and conditions for designing adaptive scaffolds. The features and effectiveness of this adaptive scaffolding e-learning system are discussed and evaluated. An…

  13. Multimedia Games for Fun and Learning English in Preschool

    ERIC Educational Resources Information Center

    Agudo, J. Enrique; Rico, Mercedes; Sánchez, Héctor

    2015-01-01

    Based on the assumption that educational software addressing Primary school learners must comprise a set of features to encourage children's creativity and development, the appropriate design of second language hypermedia adaptive games for Primary School children can pose a wide range of challenges both for the language teacher and computer…

  14. Adaptive capacity indicators to assess sustainability of urban water systems - Current application.

    PubMed

    Spiller, Marc

    2016-11-01

    Sustainability is commonly assessed along environmental, societal, economic and technological dimensions. A crucial aspect of sustainability is that inter-generational equality must be ensured. This requires that sustainability is attained in the here and now as well as into the future. Therefore, what is perceived as 'sustainable' changes as a function of societal opinion and technological and scientific progress. A concept that describes the ability of systems to change is adaptive capacity. Literature suggests that the ability of systems to adapt is an integral part of sustainable development. This paper demonstrates that indicators measuring adaptive capacity are underrepresented in current urban water sustainability studies. Furthermore, it is discussed under which sustainability dimensions adaptive capacity indicators are lacking and why. Of the >90 indicators analysed, only nine are adaptive capacity indicators, of which six are socio-cultural, two technological, one economical and none environmental. This infrequent use of adaptive capacity indicators in sustainability assessments led to the conclusion that the challenge of dynamic and uncertain urban water systems is, with the exception of the socio-cultural dimension, not yet sufficiently reflected in the application of urban water sustainability indicators. This raises concerns about the progress towards urban water systems that can transform as a response variation and change. Therefore, research should focus on developing methods and indicators that can define, evaluate and quantify adaptive capacity under the economic, environmental and technical dimension of sustainability. Furthermore, it should be evaluated whether sustainability frameworks that focus on the control processes of urban water systems are more suitable for measuring adaptive capacity, than the assessments along environmental, economic, socio-cultural and technological dimensions. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Performance benefits of adaptive, multimicrophone, interference-canceling systems in everyday environments

    NASA Astrophysics Data System (ADS)

    Desloge, Joseph G.; Zimmer, Martin J.; Zurek, Patrick M.

    2004-05-01

    Adaptive multimicrophone systems are currently used for a variety of noise-cancellation applications (such as hearing aids) to preserve signals arriving from a particular (target) direction while canceling other (jammer) signals in the environment. Although the performance of these systems is known to degrade with increasing reverberation, there are few measurements of adaptive performance in everyday reverberant environments. In this study, adaptive performance was compared to that of a simple, nonadaptive cardioid microphone to determine a measure of adaptive benefit. Both systems used recordings (at an Fs of 22050 Hz) from the same two omnidirectional microphones, which were separated by 1 cm. Four classes of environment were considered: outdoors, household, parking garage, and public establishment. Sources were either environmental noises (e.g., household appliances, restaurant noise) or a controlled noise source. In all situations, no target was present (i.e., all signals were jammers) to obtain maximal jammer cancellation. Adaptive processing was based upon the Griffiths-Jim generalized sidelobe canceller using filter lengths up to 400 points. Average intelligibility-weighted adaptive benefit levels at a source distance of 1 m were, at most, 1.5 dB for public establishments, 2 dB for household rooms and the parking garage, and 3 dB outdoors. [Work supported by NIOSH.

  16. Adaptable state based control system

    NASA Technical Reports Server (NTRS)

    Rasmussen, Robert D. (Inventor); Dvorak, Daniel L. (Inventor); Gostelow, Kim P. (Inventor); Starbird, Thomas W. (Inventor); Gat, Erann (Inventor); Chien, Steve Ankuo (Inventor); Keller, Robert M. (Inventor)

    2004-01-01

    An autonomous controller, comprised of a state knowledge manager, a control executor, hardware proxies and a statistical estimator collaborates with a goal elaborator, with which it shares common models of the behavior of the system and the controller. The elaborator uses the common models to generate from temporally indeterminate sets of goals, executable goals to be executed by the controller. The controller may be updated to operate in a different system or environment than that for which it was originally designed by the replacement of shared statistical models and by the instantiation of a new set of state variable objects derived from a state variable class. The adaptation of the controller does not require substantial modification of the goal elaborator for its application to the new system or environment.

  17. An adaptive robust controller for time delay maglev transportation systems

    NASA Astrophysics Data System (ADS)

    Milani, Reza Hamidi; Zarabadipour, Hassan; Shahnazi, Reza

    2012-12-01

    For engineering systems, uncertainties and time delays are two important issues that must be considered in control design. Uncertainties are often encountered in various dynamical systems due to modeling errors, measurement noises, linearization and approximations. Time delays have always been among the most difficult problems encountered in process control. In practical applications of feedback control, time delay arises frequently and can severely degrade closed-loop system performance and in some cases, drives the system to instability. Therefore, stability analysis and controller synthesis for uncertain nonlinear time-delay systems are important both in theory and in practice and many analytical techniques have been developed using delay-dependent Lyapunov function. In the past decade the magnetic and levitation (maglev) transportation system as a new system with high functionality has been the focus of numerous studies. However, maglev transportation systems are highly nonlinear and thus designing controller for those are challenging. The main topic of this paper is to design an adaptive robust controller for maglev transportation systems with time-delay, parametric uncertainties and external disturbances. In this paper, an adaptive robust control (ARC) is designed for this purpose. It should be noted that the adaptive gain is derived from Lyapunov-Krasovskii synthesis method, therefore asymptotic stability is guaranteed.

  18. An exploratory study of the impact of hypermedia-based approach and science-in-fiction approach for instruction on the polymerase chain reaction

    NASA Astrophysics Data System (ADS)

    Britton, Lynda A.

    1998-12-01

    Exploration of meaningful learning of the polymerase chain reaction (PCR) followed instruction by a researcher-developed hypermedia computer program that incorporated human constructivist principles and a "science-in-fiction" chapter of a novel that described PCR. Human constructivism is the Ausubel-Novak-Gowin (1997) meaningful learning theory that supports science learning through graphic representations and multiple examples. Science-in-fiction is a new genre of fiction introduced by the prominent scientist, Carl Djerassi, to engender an appreciation for science, and its ethical dilemmas. Chapter 19 of Djerassi's 1994 novel, The Bourbaki Gambit, was placed into hypermedia format to standardize the presentation. As part of a clinical microbiology course in the medical technology curriculum at a major medical center in the Deep South, 10 undergraduates participated in this study. Each first read The Bourbaki Gambit, and then half of the participants experienced the human constructivist approach first (the PCR group) while the others first encountered the science-in-fiction approach (the Chapter 19 group). For the rest, the order of presentation was reversed, so that all experienced both programs. Students' explanations while using the computer were videotaped. Students were tested and interviewed before experiencing either program, after their first instructional session, and again after the second instructional session. These students were also assessed on their knowledge of the nature of science by taking the Nature of Science Questionnaire, before and after instruction (Roach, 1993) and interviewed as a cross-check on its reliability. Students' preferred learning approaches were determined using Schmeck's Inventory of Learning Processes (Schmeck, Ribich, & Ramanaiah, 1977). Data were collected and analyzed both qualitatively and quantitatively using appropriate verbal analysis techniques (Chi, 1997). All but three students reached a structural level of PCR

  19. A dual-modal retinal imaging system with adaptive optics.

    PubMed

    Meadway, Alexander; Girkin, Christopher A; Zhang, Yuhua

    2013-12-02

    An adaptive optics scanning laser ophthalmoscope (AO-SLO) is adapted to provide optical coherence tomography (OCT) imaging. The AO-SLO function is unchanged. The system uses the same light source, scanning optics, and adaptive optics in both imaging modes. The result is a dual-modal system that can acquire retinal images in both en face and cross-section planes at the single cell level. A new spectral shaping method is developed to reduce the large sidelobes in the coherence profile of the OCT imaging when a non-ideal source is used with a minimal introduction of noise. The technique uses a combination of two existing digital techniques. The thickness and position of the traditionally named inner segment/outer segment junction are measured from individual photoreceptors. In-vivo images of healthy and diseased human retinas are demonstrated.

  20. The Role of Co-Regulated Learning during Students' Understanding of Complex Systems with Hypermedia.

    ERIC Educational Resources Information Center

    Azevedo, Roger; Cromley, Jennifer G.; Seibert, Diane; Tron, Myriam

    This study examined the role of different scaffolding instructional interventions in facilitating students' shift to more sophisticated mental models as indicated by both performance and process data. Undergraduate students (n=51) were randomly assigned to use of one of three scaffolding conditions (adaptive scaffolding (AS), fixed scaffolding…

  1. Control of adaptive immunity by the innate immune system.

    PubMed

    Iwasaki, Akiko; Medzhitov, Ruslan

    2015-04-01

    Microbial infections are recognized by the innate immune system both to elicit immediate defense and to generate long-lasting adaptive immunity. To detect and respond to vastly different groups of pathogens, the innate immune system uses several recognition systems that rely on sensing common structural and functional features associated with different classes of microorganisms. These recognition systems determine microbial location, viability, replication and pathogenicity. Detection of these features by recognition pathways of the innate immune system is translated into different classes of effector responses though specialized populations of dendritic cells. Multiple mechanisms for the induction of immune responses are variations on a common design principle wherein the cells that sense infections produce one set of cytokines to induce lymphocytes to produce another set of cytokines, which in turn activate effector responses. Here we discuss these emerging principles of innate control of adaptive immunity.

  2. Capturing flight system test engineering expertise: Lessons learned

    NASA Technical Reports Server (NTRS)

    Woerner, Irene Wong

    1991-01-01

    Within a few years, JPL will be challenged by the most active mission set in history. Concurrently, flight systems are increasingly more complex. Presently, the knowledge to conduct integration and test of spacecraft and large instruments is held by a few key people, each with many years of experience. JPL is in danger of losing a significant amount of this critical expertise, through retirement, during a period when demand for this expertise is rapidly increasing. The most critical issue at hand is to collect and retain this expertise and develop tools that would ensure the ability to successfully perform the integration and test of future spacecraft and large instruments. The proposed solution was to capture and codity a subset of existing knowledge, and to utilize this captured expertise in knowledge-based systems. First year results and activities planned for the second year of this on-going effort are described. Topics discussed include lessons learned in knowledge acquisition and elicitation techniques, life-cycle paradigms, and rapid prototyping of a knowledge-based advisor (Spacecraft Test Assistant) and a hypermedia browser (Test Engineering Browser). The prototype Spacecraft Test Assistant supports a subset of integration and test activities for flight systems. Browser is a hypermedia tool that allows users easy perusal of spacecraft test topics. A knowledge acquisition tool called ConceptFinder which was developed to search through large volumes of data for related concepts is also described and is modified to semi-automate the process of creating hypertext links.

  3. Adaptable radiation monitoring system and method

    DOEpatents

    Archer, Daniel E [Livermore, CA; Beauchamp, Brock R [San Ramon, CA; Mauger, G Joseph [Livermore, CA; Nelson, Karl E [Livermore, CA; Mercer, Michael B [Manteca, CA; Pletcher, David C [Sacramento, CA; Riot, Vincent J [Berkeley, CA; Schek, James L [Tracy, CA; Knapp, David A [Livermore, CA

    2006-06-20

    A portable radioactive-material detection system capable of detecting radioactive sources moving at high speeds. The system has at least one radiation detector capable of detecting gamma-radiation and coupled to an MCA capable of collecting spectral data in very small time bins of less than about 150 msec. A computer processor is connected to the MCA for determining from the spectral data if a triggering event has occurred. Spectral data is stored on a data storage device, and a power source supplies power to the detection system. Various configurations of the detection system may be adaptably arranged for various radiation detection scenarios. In a preferred embodiment, the computer processor operates as a server which receives spectral data from other networked detection systems, and communicates the collected data to a central data reporting system.

  4. [Caffeine and adaptive changes in the circulatory system during pregnancy].

    PubMed

    Cendrowska-Pinkosz, Monika; Dworzański, Wojciech; Krauze, Magdalena; Burdan, Franciszek

    2017-01-23

    Adaptive physiological changes that occur in pregnant women can fluctuate with the intake of substances with proven, adverse biological effect on the body. Due to the fact that caffeine is one of the most chronically used xenobiotics, the impact of consuming caffeine on adaptive processes in the circulatory system of a pregnant women required a research. Many researchers emphasise its negative effect on the circulatory system of the mother and her offspring. However, in spite of years of observation, there is no clear answer to what extent dose or in what period of time the caffeine modulates the adaptive processes during pregnancy. Because of the potential risk the supply of caffeine during pregnancy should be subjected to considerable restrictions.

  5. Guiding climate change adaptation within vulnerable natural resource management systems.

    PubMed

    Bardsley, Douglas K; Sweeney, Susan M

    2010-05-01

    Climate change has the potential to compromise the sustainability of natural resources in Mediterranean climatic systems, such that short-term reactive responses will increasingly be insufficient to ensure effective management. There is a simultaneous need for both the clear articulation of the vulnerabilities of specific management systems to climate risk, and the development of appropriate short- and long-term strategic planning responses that anticipate environmental change or allow for sustainable adaptive management in response to trends in resource condition. Governments are developing climate change adaptation policy frameworks, but without the recognition of the importance of responding strategically, regional stakeholders will struggle to manage future climate risk. In a partnership between the South Australian Government, the Adelaide and Mt Lofty Ranges Natural Resource Management Board and the regional community, a range of available research approaches to support regional climate change adaptation decision-making, were applied and critically examined, including: scenario modelling; applied and participatory Geographical Information Systems modelling; environmental risk analysis; and participatory action learning. As managers apply ideas for adaptation within their own biophysical and socio-cultural contexts, there would be both successes and failures, but a learning orientation to societal change will enable improvements over time. A base-line target for regional responses to climate change is the ownership of the issue by stakeholders, which leads to an acceptance that effective actions to adapt are now both possible and vitally important. Beyond such baseline knowledge, the research suggests that there is a range of tools from the social and physical sciences available to guide adaptation decision-making.

  6. Guiding Climate Change Adaptation Within Vulnerable Natural Resource Management Systems

    NASA Astrophysics Data System (ADS)

    Bardsley, Douglas K.; Sweeney, Susan M.

    2010-05-01

    Climate change has the potential to compromise the sustainability of natural resources in Mediterranean climatic systems, such that short-term reactive responses will increasingly be insufficient to ensure effective management. There is a simultaneous need for both the clear articulation of the vulnerabilities of specific management systems to climate risk, and the development of appropriate short- and long-term strategic planning responses that anticipate environmental change or allow for sustainable adaptive management in response to trends in resource condition. Governments are developing climate change adaptation policy frameworks, but without the recognition of the importance of responding strategically, regional stakeholders will struggle to manage future climate risk. In a partnership between the South Australian Government, the Adelaide and Mt Lofty Ranges Natural Resource Management Board and the regional community, a range of available research approaches to support regional climate change adaptation decision-making, were applied and critically examined, including: scenario modelling; applied and participatory Geographical Information Systems modelling; environmental risk analysis; and participatory action learning. As managers apply ideas for adaptation within their own biophysical and socio-cultural contexts, there would be both successes and failures, but a learning orientation to societal change will enable improvements over time. A base-line target for regional responses to climate change is the ownership of the issue by stakeholders, which leads to an acceptance that effective actions to adapt are now both possible and vitally important. Beyond such baseline knowledge, the research suggests that there is a range of tools from the social and physical sciences available to guide adaptation decision-making.

  7. Adaptive-passive vibration control systems for industrial applications

    NASA Astrophysics Data System (ADS)

    Mayer, D.; Pfeiffer, T.; Vrbata, J.; Melz, T.

    2015-04-01

    Tuned vibration absorbers have become common for passive vibration reduction in many industrial applications. Lightly damped absorbers (also called neutralizers) can be used to suppress narrowband disturbances by tuning them to the excitation frequency. If the resonance is adapted in-operation, the performance of those devices can be significantly enhanced, or inertial mass can be decreased. However, the integration of actuators, sensors and control electronics into the system raises new design challenges. In this work, the development of adaptive-passive systems for vibration reduction at an industrial scale is presented. As an example, vibration reduction of a ship engine was studied in a full scale test. Simulations were used to study the feasibility and evaluate the system concept at an early stage. Several ways to adjust the resonance of the neutralizer were evaluated, including piezoelectric actuation and common mechatronic drives. Prototypes were implemented and tested. Since vibration absorbers suffer from high dynamic loads, reliability tests were used to assess the long-term behavior under operational conditions and to improve the components. It was proved that the adaptive systems are capable to withstand the mechanical loads in an industrial application. Also a control strategy had to be implemented in order to track the excitation frequency. The most mature concepts were integrated into the full scale test. An imbalance exciter was used to simulate the engine vibrations at a realistic level experimentally. The neutralizers were tested at varying excitation frequencies to evaluate the tracking capabilities of the control system. It was proved that a significant vibration reduction is possible.

  8. An adaptive semantic based mediation system for data interoperability among Health Information Systems.

    PubMed

    Khan, Wajahat Ali; Khattak, Asad Masood; Hussain, Maqbool; Amin, Muhammad Bilal; Afzal, Muhammad; Nugent, Christopher; Lee, Sungyoung

    2014-08-01

    Heterogeneity in the management of the complex medical data, obstructs the attainment of data level interoperability among Health Information Systems (HIS). This diversity is dependent on the compliance of HISs with different healthcare standards. Its solution demands a mediation system for the accurate interpretation of data in different heterogeneous formats for achieving data interoperability. We propose an adaptive AdapteR Interoperability ENgine mediation system called ARIEN, that arbitrates between HISs compliant to different healthcare standards for accurate and seamless information exchange to achieve data interoperability. ARIEN stores the semantic mapping information between different standards in the Mediation Bridge Ontology (MBO) using ontology matching techniques. These mappings are provided by our System for Parallel Heterogeneity (SPHeRe) matching system and Personalized-Detailed Clinical Model (P-DCM) approach to guarantee accuracy of mappings. The realization of the effectiveness of the mappings stored in the MBO is evaluation of the accuracy in transformation process among different standard formats. We evaluated our proposed system with the transformation process of medical records between Clinical Document Architecture (CDA) and Virtual Medical Record (vMR) standards. The transformation process achieved over 90 % of accuracy level in conversion process between CDA and vMR standards using pattern oriented approach from the MBO. The proposed mediation system improves the overall communication process between HISs. It provides an accurate and seamless medical information exchange to ensure data interoperability and timely healthcare services to patients.

  9. Adaptive cyber-attack modeling system

    NASA Astrophysics Data System (ADS)

    Gonsalves, Paul G.; Dougherty, Edward T.

    2006-05-01

    The pervasiveness of software and networked information systems is evident across a broad spectrum of business and government sectors. Such reliance provides an ample opportunity not only for the nefarious exploits of lone wolf computer hackers, but for more systematic software attacks from organized entities. Much effort and focus has been placed on preventing and ameliorating network and OS attacks, a concomitant emphasis is required to address protection of mission critical software. Typical software protection technique and methodology evaluation and verification and validation (V&V) involves the use of a team of subject matter experts (SMEs) to mimic potential attackers or hackers. This manpower intensive, time-consuming, and potentially cost-prohibitive approach is not amenable to performing the necessary multiple non-subjective analyses required to support quantifying software protection levels. To facilitate the evaluation and V&V of software protection solutions, we have designed and developed a prototype adaptive cyber attack modeling system. Our approach integrates an off-line mechanism for rapid construction of Bayesian belief network (BN) attack models with an on-line model instantiation, adaptation and knowledge acquisition scheme. Off-line model construction is supported via a knowledge elicitation approach for identifying key domain requirements and a process for translating these requirements into a library of BN-based cyber-attack models. On-line attack modeling and knowledge acquisition is supported via BN evidence propagation and model parameter learning.

  10. Method study on fuzzy-PID adaptive control of electric-hydraulic hitch system

    NASA Astrophysics Data System (ADS)

    Li, Mingsheng; Wang, Liubu; Liu, Jian; Ye, Jin

    2017-03-01

    In this paper, fuzzy-PID adaptive control method is applied to the control of tractor electric-hydraulic hitch system. According to the characteristics of the system, a fuzzy-PID adaptive controller is designed and the electric-hydraulic hitch system model is established. Traction control and position control performance simulation are carried out with the common PID control method. A field test rig was set up to test the electric-hydraulic hitch system. The test results showed that, after the fuzzy-PID adaptive control is adopted, when the tillage depth steps from 0.1m to 0.3m, the system transition process time is 4s, without overshoot, and when the tractive force steps from 3000N to 7000N, the system transition process time is 5s, the system overshoot is 25%.

  11. Variable Neural Adaptive Robust Control: A Switched System Approach

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lian, Jianming; Hu, Jianghai; Zak, Stanislaw H.

    2015-05-01

    Variable neural adaptive robust control strategies are proposed for the output tracking control of a class of multi-input multi-output uncertain systems. The controllers incorporate a variable-structure radial basis function (RBF) network as the self-organizing approximator for unknown system dynamics. The variable-structure RBF network solves the problem of structure determination associated with fixed-structure RBF networks. It can determine the network structure on-line dynamically by adding or removing radial basis functions according to the tracking performance. The structure variation is taken into account in the stability analysis of the closed-loop system using a switched system approach with the aid of the piecewisemore » quadratic Lyapunov function. The performance of the proposed variable neural adaptive robust controllers is illustrated with simulations.« less

  12. Learning-Based Adaptive Optimal Tracking Control of Strict-Feedback Nonlinear Systems.

    PubMed

    Gao, Weinan; Jiang, Zhong-Ping; Weinan Gao; Zhong-Ping Jiang; Gao, Weinan; Jiang, Zhong-Ping

    2018-06-01

    This paper proposes a novel data-driven control approach to address the problem of adaptive optimal tracking for a class of nonlinear systems taking the strict-feedback form. Adaptive dynamic programming (ADP) and nonlinear output regulation theories are integrated for the first time to compute an adaptive near-optimal tracker without any a priori knowledge of the system dynamics. Fundamentally different from adaptive optimal stabilization problems, the solution to a Hamilton-Jacobi-Bellman (HJB) equation, not necessarily a positive definite function, cannot be approximated through the existing iterative methods. This paper proposes a novel policy iteration technique for solving positive semidefinite HJB equations with rigorous convergence analysis. A two-phase data-driven learning method is developed and implemented online by ADP. The efficacy of the proposed adaptive optimal tracking control methodology is demonstrated via a Van der Pol oscillator with time-varying exogenous signals.

  13. Emergence, institutionalization and renewal: Rhythms of adaptive governance in complex social-ecological systems.

    PubMed

    Chaffin, Brian C; Gunderson, Lance H

    2016-01-01

    Adaptive governance provides the capacity for environmental managers and decision makers to confront variable degrees of uncertainty inherent to complex social-ecological systems. Current theoretical conceptualizations of adaptive governance represent a series of structures and processes best suited for either adapting or transforming existing environmental governance regimes towards forms flexible enough to confront rapid ecological change. As the number of empirical examples of adaptive governance described in the literature grows, the conceptual basis of adaptive governance remains largely under theorized. We argue that reconnecting adaptive governance with foundational concepts of ecological resilience-specifically Panarchy and the adaptive cycle of complex systems-highlights the importance of episodic disturbances and cross-scale interactions in triggering reorganizations in governance. By envisioning the processes of adaptive governance through the lens of Panarchy, scholars and practitioners alike will be better able to identify the emergence of adaptive governance, as well as take advantage of opportunities to institutionalize this type of governance in pursuit of sustainability outcomes. The synergistic analysis of adaptive governance and Panarchy can provide critical insight for analyzing the role of social dynamics during oscillating periods of stability and instability in social-ecological systems. A deeper understanding of the potential for cross-scale interactions to shape adaptive governance regimes may be useful as society faces the challenge of mitigating the impacts of global environmental change. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Risk-Return Relationship in a Complex Adaptive System

    PubMed Central

    Song, Kunyu; An, Kenan; Yang, Guang; Huang, Jiping

    2012-01-01

    For survival and development, autonomous agents in complex adaptive systems involving the human society must compete against or collaborate with others for sharing limited resources or wealth, by using different methods. One method is to invest, in order to obtain payoffs with risk. It is a common belief that investments with a positive risk-return relationship (namely, high risk high return and vice versa) are dominant over those with a negative risk-return relationship (i.e., high risk low return and vice versa) in the human society; the belief has a notable impact on daily investing activities of investors. Here we investigate the risk-return relationship in a model complex adaptive system, in order to study the effect of both market efficiency and closeness that exist in the human society and play an important role in helping to establish traditional finance/economics theories. We conduct a series of computer-aided human experiments, and also perform agent-based simulations and theoretical analysis to confirm the experimental observations and reveal the underlying mechanism. We report that investments with a negative risk-return relationship have dominance over those with a positive risk-return relationship instead in such a complex adaptive systems. We formulate the dynamical process for the system's evolution, which helps to discover the different role of identical and heterogeneous preferences. This work might be valuable not only to complexity science, but also to finance and economics, to management and social science, and to physics. PMID:22479416

  15. Risk-return relationship in a complex adaptive system.

    PubMed

    Song, Kunyu; An, Kenan; Yang, Guang; Huang, Jiping

    2012-01-01

    For survival and development, autonomous agents in complex adaptive systems involving the human society must compete against or collaborate with others for sharing limited resources or wealth, by using different methods. One method is to invest, in order to obtain payoffs with risk. It is a common belief that investments with a positive risk-return relationship (namely, high risk high return and vice versa) are dominant over those with a negative risk-return relationship (i.e., high risk low return and vice versa) in the human society; the belief has a notable impact on daily investing activities of investors. Here we investigate the risk-return relationship in a model complex adaptive system, in order to study the effect of both market efficiency and closeness that exist in the human society and play an important role in helping to establish traditional finance/economics theories. We conduct a series of computer-aided human experiments, and also perform agent-based simulations and theoretical analysis to confirm the experimental observations and reveal the underlying mechanism. We report that investments with a negative risk-return relationship have dominance over those with a positive risk-return relationship instead in such a complex adaptive systems. We formulate the dynamical process for the system's evolution, which helps to discover the different role of identical and heterogeneous preferences. This work might be valuable not only to complexity science, but also to finance and economics, to management and social science, and to physics.

  16. Initial results from the Lick Observatory Laser Guide Star Adaptive Optics System

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Olivier, S.S.; An, J.; Avicola, K.

    1995-11-08

    A prototype adaptive optics system has been installed and tested on the 3 m Shane telescope at Lick Observatory. The adaptive optics system performance, using bright natural guide stars, is consistent with expectations based on theory. A sodium-layer laser guide star system has also been installed and tested on the Shane telescope. Operating at 15 W, the laser system produces a 9th magnitude guide star with seeing-limited size at 589 nm. Using the laser guide star, the adaptive optics system has reduced the wavefront phase variance on scales above 50 cm by a factor of 4. These results represent themore » first continuous wavefront phase correction using a sodium-layer laser guide star. Assuming tip-tilt is removed using a natural guide star, the measured control loop performance should produce images with a Strehl ratio of 0.4 at 2.2 {mu}m in 1 arc second seeing. Additional calibration procedures must be implemented in order to achieve these results with the prototype Lick adaptive optics system.« less

  17. Adaptive and neuroadaptive control for nonnegative and compartmental dynamical systems

    NASA Astrophysics Data System (ADS)

    Volyanskyy, Kostyantyn Y.

    Neural networks have been extensively used for adaptive system identification as well as adaptive and neuroadaptive control of highly uncertain systems. The goal of adaptive and neuroadaptive control is to achieve system performance without excessive reliance on system models. To improve robustness and the speed of adaptation of adaptive and neuroadaptive controllers several controller architectures have been proposed in the literature. In this dissertation, we develop a new neuroadaptive control architecture for nonlinear uncertain dynamical systems. The proposed framework involves a novel controller architecture with additional terms in the update laws that are constructed using a moving window of the integrated system uncertainty. These terms can be used to identify the ideal system weights of the neural network as well as effectively suppress system uncertainty. Linear and nonlinear parameterizations of the system uncertainty are considered and state and output feedback neuroadaptive controllers are developed. Furthermore, we extend the developed framework to discrete-time dynamical systems. To illustrate the efficacy of the proposed approach we apply our results to an aircraft model with wing rock dynamics, a spacecraft model with unknown moment of inertia, and an unmanned combat aerial vehicle undergoing actuator failures, and compare our results with standard neuroadaptive control methods. Nonnegative systems are essential in capturing the behavior of a wide range of dynamical systems involving dynamic states whose values are nonnegative. A sub-class of nonnegative dynamical systems are compartmental systems. These systems are derived from mass and energy balance considerations and are comprised of homogeneous interconnected microscopic subsystems or compartments which exchange variable quantities of material via intercompartmental flow laws. In this dissertation, we develop direct adaptive and neuroadaptive control framework for stabilization, disturbance

  18. Neural network L1 adaptive control of MIMO systems with nonlinear uncertainty.

    PubMed

    Zhen, Hong-tao; Qi, Xiao-hui; Li, Jie; Tian, Qing-min

    2014-01-01

    An indirect adaptive controller is developed for a class of multiple-input multiple-output (MIMO) nonlinear systems with unknown uncertainties. This control system is comprised of an L 1 adaptive controller and an auxiliary neural network (NN) compensation controller. The L 1 adaptive controller has guaranteed transient response in addition to stable tracking. In this architecture, a low-pass filter is adopted to guarantee fast adaptive rate without generating high-frequency oscillations in control signals. The auxiliary compensation controller is designed to approximate the unknown nonlinear functions by MIMO RBF neural networks to suppress the influence of uncertainties. NN weights are tuned on-line with no prior training and the project operator ensures the weights bounded. The global stability of the closed-system is derived based on the Lyapunov function. Numerical simulations of an MIMO system coupled with nonlinear uncertainties are used to illustrate the practical potential of our theoretical results.

  19. RASCAL: A Rudimentary Adaptive System for Computer-Aided Learning.

    ERIC Educational Resources Information Center

    Stewart, John Christopher

    Both the background of computer-assisted instruction (CAI) systems in general and the requirements of a computer-aided learning system which would be a reasonable assistant to a teacher are discussed. RASCAL (Rudimentary Adaptive System for Computer-Aided Learning) is a first attempt at defining a CAI system which would individualize the learning…

  20. Evolution of complement as an effector system in innate and adaptive immunity.

    PubMed

    Sunyer, J Oriol; Boshra, Hani; Lorenzo, Gema; Parra, David; Freedman, Bruce; Bosch, Nina

    2003-01-01

    For a long time, the complement system in mammals has been regarded as a biological system that plays an essential role in innate immunity. More recently, it has been recognized that the complement system contributes heavily to the generation and development of an acquired immune response. In fact, this ancient mechanism of defense has evolved from a primitive mechanism of innate immune recognition in invertebrate species to that of an effector system that bridges the innate with the adaptive immune response in vertebrate species. When and how did complement evolve into a shared effector system between innate and adaptive immunity? To answer this question, our group is interested in understanding the role of complement in innate and adaptive immune responses in an evolutionary relevant species: the teleost fish. The attractiveness of this species as an animal model is based on two important facts. First, teleost fish are one of the oldest animal species to have developed an adaptive immune response. Second, the complement system of teleost fish offers a unique feature, which is the structural and functional diversity of its main effector protein, C3, the third component of the complement system.

  1. Adaptive Wavelet Coding Applied in a Wireless Control System.

    PubMed

    Gama, Felipe O S; Silveira, Luiz F Q; Salazar, Andrés O

    2017-12-13

    Wireless control systems can sense, control and act on the information exchanged between the wireless sensor nodes in a control loop. However, the exchanged information becomes susceptible to the degenerative effects produced by the multipath propagation. In order to minimize the destructive effects characteristic of wireless channels, several techniques have been investigated recently. Among them, wavelet coding is a good alternative for wireless communications for its robustness to the effects of multipath and its low computational complexity. This work proposes an adaptive wavelet coding whose parameters of code rate and signal constellation can vary according to the fading level and evaluates the use of this transmission system in a control loop implemented by wireless sensor nodes. The performance of the adaptive system was evaluated in terms of bit error rate (BER) versus E b / N 0 and spectral efficiency, considering a time-varying channel with flat Rayleigh fading, and in terms of processing overhead on a control system with wireless communication. The results obtained through computational simulations and experimental tests show performance gains obtained by insertion of the adaptive wavelet coding in a control loop with nodes interconnected by wireless link. These results enable the use of this technique in a wireless link control loop.

  2. Water System Adaptation to Hydrological Changes: Module 10, Basic Principles of Incorporating Adaptation Science into Hydrologic Planning and Design

    EPA Science Inventory

    This course will introduce students to the fundamental principles of water system adaptation to hydrological changes, with emphasis on data analysis and interpretation, technical planning, and computational modeling. Starting with real-world scenarios and adaptation needs, the co...

  3. Active Hearing Mechanisms Inspire Adaptive Amplification in an Acoustic Sensor System.

    PubMed

    Guerreiro, Jose; Reid, Andrew; Jackson, Joseph C; Windmill, James F C

    2018-06-01

    Over many millions of years of evolution, nature has developed some of the most adaptable sensors and sensory systems possible, capable of sensing, conditioning and processing signals in a very power- and size-effective manner. By looking into biological sensors and systems as a source of inspiration, this paper presents the study of a bioinspired concept of signal processing at the sensor level. By exploiting a feedback control mechanism between a front-end acoustic receiver and back-end neuronal based computation, a nonlinear amplification with hysteretic behavior is created. Moreover, the transient response of the front-end acoustic receiver can also be controlled and enhanced. A theoretical model is proposed and the concept is prototyped experimentally through an embedded system setup that can provide dynamic adaptations of a sensory system comprising a MEMS microphone placed in a closed-loop feedback system. It faithfully mimics the mosquito's active hearing response as a function of the input sound intensity. This is an adaptive acoustic sensor system concept that can be exploited by sensor and system designers within acoustics and ultrasonic engineering fields.

  4. Backstepping Design of Adaptive Neural Fault-Tolerant Control for MIMO Nonlinear Systems.

    PubMed

    Gao, Hui; Song, Yongduan; Wen, Changyun

    In this paper, an adaptive controller is developed for a class of multi-input and multioutput nonlinear systems with neural networks (NNs) used as a modeling tool. It is shown that all the signals in the closed-loop system with the proposed adaptive neural controller are globally uniformly bounded for any external input in . In our control design, the upper bound of the NN modeling error and the gains of external disturbance are characterized by unknown upper bounds, which is more rational to establish the stability in the adaptive NN control. Filter-based modification terms are used in the update laws of unknown parameters to improve the transient performance. Finally, fault-tolerant control is developed to accommodate actuator failure. An illustrative example applying the adaptive controller to control a rigid robot arm shows the validation of the proposed controller.In this paper, an adaptive controller is developed for a class of multi-input and multioutput nonlinear systems with neural networks (NNs) used as a modeling tool. It is shown that all the signals in the closed-loop system with the proposed adaptive neural controller are globally uniformly bounded for any external input in . In our control design, the upper bound of the NN modeling error and the gains of external disturbance are characterized by unknown upper bounds, which is more rational to establish the stability in the adaptive NN control. Filter-based modification terms are used in the update laws of unknown parameters to improve the transient performance. Finally, fault-tolerant control is developed to accommodate actuator failure. An illustrative example applying the adaptive controller to control a rigid robot arm shows the validation of the proposed controller.

  5. ISAARE: Information System for Adaptive, Assistive, and Recreational Equipment: Volume I: Existence; Volume II, Communication; Volume V, Adaptation.

    ERIC Educational Resources Information Center

    Melichar, Joseph F.

    Described as part of the Information System for Adaptive, Assistive and Recreational Equipment are equipment items for physically handicapped pupils in the functional areas of existence, equipment and adaptation. Reviewed in the existence section are such items as assistive food containers and container stabilizers, feeder accessories, bowel and…

  6. Extensible Adaptive System for STEM Learning

    DTIC Science & Technology

    2013-07-16

    Copyright 2013 Raytheon BBN Technologies Corp. All Rights Reserved ONR STEM Grand Challenge Extensible Adaptive System for STEM Learning ...Contract # N00014-12-C-0535 Raytheon BBN Technologies Corp. (BBN) Reference # 14217 In partial fulfillment of contract deliverable item # A001...Quarterly Progress Report #2 April 7, 2013 –July 6, 2013 Submitted July 16, 2013 BBN Technical POC: John Makhoul Raytheon BBN Technologies

  7. Interactive knowledge networks for interdisciplinary course navigation within Moodle.

    PubMed

    Scherl, Andre; Dethleffsen, Kathrin; Meyer, Michael

    2012-12-01

    Web-based hypermedia learning environments are widely used in modern education and seem particularly well suited for interdisciplinary learning. Previous work has identified guidance through these complex environments as a crucial problem of their acceptance and efficiency. We reasoned that map-based navigation might provide straightforward and effortless orientation. To achieve this, we developed a clickable and user-oriented concept map-based navigation plugin. This tool is implemented as an extension of Moodle, a widely used learning management system. It visualizes inner and interdisciplinary relations between learning objects and is generated dynamically depending on user set parameters and interactions. This plugin leaves the choice of navigation type to the user and supports direct guidance. Previously developed and evaluated face-to-face interdisciplinary learning materials bridging physiology and physics courses of a medical curriculum were integrated as learning objects, the relations of which were defined by metadata. Learning objects included text pages, self-assessments, videos, animations, and simulations. In a field study, we analyzed the effects of this learning environment on physiology and physics knowledge as well as the transfer ability of third-term medical students. Data were generated from pre- and posttest questionnaires and from tracking student navigation. Use of the hypermedia environment resulted in a significant increase of knowledge and transfer capability. Furthermore, the efficiency of learning was enhanced. We conclude that hypermedia environments based on Moodle and enriched by concept map-based navigation tools can significantly support interdisciplinary learning. Implementation of adaptivity may further strengthen this approach.

  8. A Conceptual Framework for Planning Systemic Human Adaptation to Global Warming.

    PubMed

    Tait, Peter W; Hanna, Elizabeth G

    2015-08-31

    Human activity is having multiple, inter-related effects on ecosystems. Greenhouse gas emissions persisting along current trajectories threaten to significantly alter human society. At 0.85 °C of anthropogenic warming, deleterious human impacts are acutely evident. Additional warming of 0.5 °C-1.0 °C from already emitted CO₂ will further intensify extreme heat and damaging storm events. Failing to sufficiently address this trend will have a heavy human toll directly and indirectly on health. Along with mitigation efforts, societal adaptation to a warmer world is imperative. Adaptation efforts need to be significantly upscaled to prepare society to lessen the public health effects of rising temperatures. Modifying societal behaviour is inherently complex and presents a major policy challenge. We propose a social systems framework for conceptualizing adaptation that maps out three domains within the adaptation policy landscape: acclimatisation, behavioural adaptation and technological adaptation, which operate at societal and personal levels. We propose that overlaying this framework on a systems approach to societal change planning methods will enhance governments' capacity and efficacy in strategic planning for adaptation. This conceptual framework provides a policy oriented planning assessment tool that will help planners match interventions to the behaviours being targeted for change. We provide illustrative examples to demonstrate the framework's application as a planning tool.

  9. Fuzzy Adaptive Decentralized Optimal Control for Strict Feedback Nonlinear Large-Scale Systems.

    PubMed

    Sun, Kangkang; Sui, Shuai; Tong, Shaocheng

    2018-04-01

    This paper considers the optimal decentralized fuzzy adaptive control design problem for a class of interconnected large-scale nonlinear systems in strict feedback form and with unknown nonlinear functions. The fuzzy logic systems are introduced to learn the unknown dynamics and cost functions, respectively, and a state estimator is developed. By applying the state estimator and the backstepping recursive design algorithm, a decentralized feedforward controller is established. By using the backstepping decentralized feedforward control scheme, the considered interconnected large-scale nonlinear system in strict feedback form is changed into an equivalent affine large-scale nonlinear system. Subsequently, an optimal decentralized fuzzy adaptive control scheme is constructed. The whole optimal decentralized fuzzy adaptive controller is composed of a decentralized feedforward control and an optimal decentralized control. It is proved that the developed optimal decentralized controller can ensure that all the variables of the control system are uniformly ultimately bounded, and the cost functions are the smallest. Two simulation examples are provided to illustrate the validity of the developed optimal decentralized fuzzy adaptive control scheme.

  10. Selecting, adapting, and sustaining programs in health care systems

    PubMed Central

    Zullig, Leah L; Bosworth, Hayden B

    2015-01-01

    Practitioners and researchers often design behavioral programs that are effective for a specific population or problem. Despite their success in a controlled setting, relatively few programs are scaled up and implemented in health care systems. Planning for scale-up is a critical, yet often overlooked, element in the process of program design. Equally as important is understanding how to select a program that has already been developed, and adapt and implement the program to meet specific organizational goals. This adaptation and implementation requires attention to organizational goals, available resources, and program cost. We assert that translational behavioral medicine necessitates expanding successful programs beyond a stand-alone research study. This paper describes key factors to consider when selecting, adapting, and sustaining programs for scale-up in large health care systems and applies the Knowledge to Action (KTA) Framework to a case study, illustrating knowledge creation and an action cycle of implementation and evaluation activities. PMID:25931825

  11. Intelligent control of non-linear dynamical system based on the adaptive neurocontroller

    NASA Astrophysics Data System (ADS)

    Engel, E.; Kovalev, I. V.; Kobezhicov, V.

    2015-10-01

    This paper presents an adaptive neuro-controller for intelligent control of non-linear dynamical system. The formed as the fuzzy selective neural net the adaptive neuro-controller on the base of system's state, creates the effective control signal under random perturbations. The validity and advantages of the proposed adaptive neuro-controller are demonstrated by numerical simulations. The simulation results show that the proposed controller scheme achieves real-time control speed and the competitive performance, as compared to PID, fuzzy logic controllers.

  12. Effectiveness of Adaptive Assessment versus Learner Control in a Multimedia Learning System

    ERIC Educational Resources Information Center

    Chen, Ching-Huei; Chang, Shu-Wei

    2015-01-01

    The purpose of this study was to explore the effectiveness of adaptive assessment versus learner control in a multimedia learning system designed to help secondary students learn science. Unlike other systems, this paper presents a workflow of adaptive assessment following instructional materials that better align with learners' cognitive…

  13. Survey on the use of smart and adaptive engineering systems in medicine.

    PubMed

    Abbod, M F; Linkens, D A; Mahfouf, M; Dounias, G

    2002-11-01

    In this paper, the current published knowledge about smart and adaptive engineering systems in medicine is reviewed. The achievements of frontier research in this particular field within medical engineering are described. A multi-disciplinary approach to the applications of adaptive systems is observed from the literature surveyed. The three modalities of diagnosis, imaging and therapy are considered to be an appropriate classification method for the analysis of smart systems being applied to specified medical sub-disciplines. It is expected that future research in biomedicine should identify subject areas where more advanced intelligent systems could be applied than is currently evident. The literature provides evidence of hybridisation of different types of adaptive and smart systems with applications in different areas of medical specifications. Copyright 2002 Elsevier Science B.V.

  14. Understanding health system reform - a complex adaptive systems perspective.

    PubMed

    Sturmberg, Joachim P; O'Halloran, Di M; Martin, Carmel M

    2012-02-01

    Everyone wants a sustainable well-functioning health system. However, this notion has different meaning to policy makers and funders compared to clinicians and patients. The former perceive public policy and economic constraints, the latter clinical or patient-centred strategies as the means to achieving a desired outcome. Theoretical development and critical analysis of a complex health system model. We introduce the concept of the health care vortex as a metaphor by which to understand the complex adaptive nature of health systems, and the degree to which their behaviour is predetermined by their 'shared values' or attractors. We contrast the likely functions and outcomes of a health system with a people-centred attractor and one with a financial attractor. This analysis suggests a shift in the system's attractor is fundamental to progress health reform thinking. © 2012 Blackwell Publishing Ltd.

  15. Observer-Based Adaptive Neural Network Control for Nonlinear Systems in Nonstrict-Feedback Form.

    PubMed

    Chen, Bing; Zhang, Huaguang; Lin, Chong

    2016-01-01

    This paper focuses on the problem of adaptive neural network (NN) control for a class of nonlinear nonstrict-feedback systems via output feedback. A novel adaptive NN backstepping output-feedback control approach is first proposed for nonlinear nonstrict-feedback systems. The monotonicity of system bounding functions and the structure character of radial basis function (RBF) NNs are used to overcome the difficulties that arise from nonstrict-feedback structure. A state observer is constructed to estimate the immeasurable state variables. By combining adaptive backstepping technique with approximation capability of radial basis function NNs, an output-feedback adaptive NN controller is designed through backstepping approach. It is shown that the proposed controller guarantees semiglobal boundedness of all the signals in the closed-loop systems. Two examples are used to illustrate the effectiveness of the proposed approach.

  16. Adaptive modeling, identification, and control of dynamic structural systems. I. Theory

    USGS Publications Warehouse

    Safak, Erdal

    1989-01-01

    A concise review of the theory of adaptive modeling, identification, and control of dynamic structural systems based on discrete-time recordings is presented. Adaptive methods have four major advantages over the classical methods: (1) Removal of the noise from the signal is done over the whole frequency band; (2) time-varying characteristics of systems can be tracked; (3) systems with unknown characteristics can be controlled; and (4) a small segment of the data is needed during the computations. Included in the paper are the discrete-time representation of single-input single-output (SISO) systems, models for SISO systems with noise, the concept of stochastic approximation, recursive prediction error method (RPEM) for system identification, and the adaptive control. Guidelines for model selection and model validation and the computational aspects of the method are also discussed in the paper. The present paper is the first of two companion papers. The theory given in the paper is limited to that which is necessary to follow the examples for applications in structural dynamics presented in the second paper.

  17. The beauty of simple adaptive control and new developments in nonlinear systems stability analysis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Barkana, Itzhak, E-mail: ibarkana@gmail.com

    Although various adaptive control techniques have been around for a long time and in spite of successful proofs of stability and even successful demonstrations of performance, the eventual use of adaptive control methodologies in practical real world systems has met a rather strong resistance from practitioners and has remained limited. Apparently, it is difficult to guarantee or even understand the conditions that can guarantee stable operations of adaptive control systems under realistic operational environments. Besides, it is difficult to measure the robustness of adaptive control system stability and allow it to be compared with the common and widely used measuremore » of phase margin and gain margin that is utilized by present, mainly LTI, controllers. Furthermore, customary stability analysis methods seem to imply that the mere stability of adaptive systems may be adversely affected by any tiny deviation from the pretty idealistic and assumably required stability conditions. This paper first revisits the fundamental qualities of customary direct adaptive control methodologies, in particular the classical Model Reference Adaptive Control, and shows that some of their basic drawbacks have been addressed and eliminated within the so-called Simple Adaptive Control methodology. Moreover, recent developments in the stability analysis methods of nonlinear systems show that prior conditions that were customarily assumed to be needed for stability are only apparent and can be eliminated. As a result, sufficient conditions that guarantee stability are clearly stated and lead to similarly clear proofs of stability. As many real-world applications show, once robust stability of the adaptive systems can be guaranteed, the added value of using Add-On Adaptive Control along with classical Control design techniques is pushing the desired performance beyond any previous limits.« less

  18. Information system to manage anatomical knowledge and image data about brain

    NASA Astrophysics Data System (ADS)

    Barillot, Christian; Gibaud, Bernard; Montabord, E.; Garlatti, S.; Gauthier, N.; Kanellos, I.

    1994-09-01

    This paper reports about first results obtained in a project aiming at developing a computerized system to manage knowledge about brain anatomy. The emphasis is put on the design of a knowledge base which includes a symbolic model of cerebral anatomical structures (grey nuclei, cortical structures such as gyri and sulci, verntricles, vessels, etc.) and of hypermedia facilities allowing to retrieve and display information associated with the objects (texts, drawings, images). Atlas plates digitized from a stereotactic atlas are also used to provide natural and effective communication means between the user and the system.

  19. Water System Adaptation to Hydrological Changes: Module 1, Introduction to Water System Adaptation

    EPA Science Inventory

    Contemporary water management requires resilience, the ability to meet ever increasing water needs, and capacity to adapt to abrupt or transient changes in water quality and availability. For this purpose, effective adaptation to extreme hydrological events (e.g. intense storms, ...

  20. Texture-adaptive hyperspectral video acquisition system with a spatial light modulator

    NASA Astrophysics Data System (ADS)

    Fang, Xiaojing; Feng, Jiao; Wang, Yongjin

    2014-10-01

    We present a new hybrid camera system based on spatial light modulator (SLM) to capture texture-adaptive high-resolution hyperspectral video. The hybrid camera system records a hyperspectral video with low spatial resolution using a gray camera and a high-spatial resolution video using a RGB camera. The hyperspectral video is subsampled by the SLM. The subsampled points can be adaptively selected according to the texture characteristic of the scene by combining with digital imaging analysis and computational processing. In this paper, we propose an adaptive sampling method utilizing texture segmentation and wavelet transform (WT). We also demonstrate the effectiveness of the sampled pattern on the SLM with the proposed method.

  1. Creating adaptive web recommendation system based on user behavior

    NASA Astrophysics Data System (ADS)

    Walek, Bogdan

    2018-01-01

    The paper proposes adaptive web recommendation system based on user behavior. The proposed system uses expert system to evaluating and recommending suitable items of content. Relevant items are subsequently evaluated and filtered based on history of visited items and user´s preferred categories of items. Main parts of the proposed system are presented and described. The proposed recommendation system is verified on specific example.

  2. HIDEC F-15 adaptive engine control system flight test results

    NASA Technical Reports Server (NTRS)

    Smolka, James W.

    1987-01-01

    NASA-Ames' Highly Integrated Digital Electronic Control (HIDEC) flight test program aims to develop fully integrated airframe, propulsion, and flight control systems. The HIDEC F-15 adaptive engine control system flight test program has demonstrated that significant performance improvements are obtainable through the retention of stall-free engine operation throughout the aircraft flight and maneuver envelopes. The greatest thrust increase was projected for the medium-to-high altitude flight regime at subsonic speed which is of such importance to air combat. Adaptive engine control systems such as the HIDEC F-15's can be used to upgrade the performance of existing aircraft without resort to expensive reengining programs.

  3. [Role of thyroid system in adaptation to cold].

    PubMed

    Maslov, L N; Vychuzhanova, E A; Gorbunov, A S; Tsybul'nikov, S Iu; Khaliulin, I G; Chauski, E

    2014-06-01

    Adaptation to cold promotes an increase in blood T3 and T4 levels in men and animals. The long-term cold exposure can induce a decrease in concentration of serum total and free T3 in human due to an enhancement of this hormone clearance. Endogenous catecholamines during adaptation to cold raise iodothyronine deiodinase D2 activity in brown fat due to α1-adrenergic receptor stimulation. Triiodothyronine is an inductor of iodothyronine deiodinase expression in brown fat, liver and kidney. Iodothyronine deiodinase D2 plays an important role in adaptation of organism to cold contributing to the high adrenergic reactivity of brown fat. At adaptation to cold T3 interacts with T3Rβ, it is formed T3Rβ-RXR complex, which binds to DNA with following transcription of UCP-1 and UCP-3 genes and UCP-1 and UCP-3 protein synthesis and uncoupling oxidative phosphorylation and an increase in heat production, where T3Rβ is T3-receptor-β, RXR is retinoid X-receptor, UCP is uncoupling protein. Triiodothyronine contributes to normal response to adrenergic agents of brown fat due to T3Rα activation. Sympatho-adrenomedullary and thyroid systems act as synergists in adaptation to cold.

  4. State of the art in adaptive control of robotic systems

    NASA Technical Reports Server (NTRS)

    Tosunoglu, Sabri; Tesar, Delbert

    1988-01-01

    An up-to-date assessment of adaptive control technology as applied to robotics is presented. Although the field is relatively new and does not yet represent a mature discipline, considerable attention for the design of sophisticated robot controllers has occured. In this presentation, adaptive control methods are divided into model reference adaptive systems and self-tuning regulators, with further definition of various approaches given in each class. The similarity and distinct features of the designed controllers are delineated and tabulated to enhance comparative review.

  5. Proceedings of the Annual Military Librarians Workshop (33rd) Held in San Antonio, Texas on 18-20 October 1989

    DTIC Science & Technology

    1992-12-01

    Revolution," ONLINE (1989 July):75. 6. Ibid., 76. 7. Ibid., 77. 17 HYPERMEDIA: INTERFACING IN THE INFORMATION AGE J . Wesley Regian Air Force Human...Resources Laboratory (AFSC) Brooks Air Force Base, Texas 19 HYPERMEDIA: INTERFACING IN THE INFORMATION AGE J . Wesley Regian Air Force Human Resources...AUTOMATION SYSTEM DISTRIBUTED INFORMATION ACCESS: RETRIEVAL DATABASE INTERFACE MANAGEMENT James J . Young, President Ann R Tinker Sirsi Corporation Huntsville

  6. Quantum Information Biology: From Theory of Open Quantum Systems to Adaptive Dynamics

    NASA Astrophysics Data System (ADS)

    Asano, Masanari; Basieva, Irina; Khrennikov, Andrei; Ohya, Masanori; Tanaka, Yoshiharu; Yamato, Ichiro

    This chapter reviews quantum(-like) information biology (QIB). Here biology is treated widely as even covering cognition and its derivatives: psychology and decision making, sociology, and behavioral economics and finances. QIB provides an integrative description of information processing by bio-systems at all scales of life: from proteins and cells to cognition, ecological and social systems. Mathematically QIB is based on the theory of adaptive quantum systems (which covers also open quantum systems). Ideologically QIB is based on the quantum-like (QL) paradigm: complex bio-systems process information in accordance with the laws of quantum information and probability. This paradigm is supported by plenty of statistical bio-data collected at all bio-scales. QIB re ects the two fundamental principles: a) adaptivity; and, b) openness (bio-systems are fundamentally open). In addition, quantum adaptive dynamics provides the most generally possible mathematical representation of these principles.

  7. HyFIS: adaptive neuro-fuzzy inference systems and their application to nonlinear dynamical systems.

    PubMed

    Kim, J; Kasabov, N

    1999-11-01

    This paper proposes an adaptive neuro-fuzzy system, HyFIS (Hybrid neural Fuzzy Inference System), for building and optimising fuzzy models. The proposed model introduces the learning power of neural networks to fuzzy logic systems and provides linguistic meaning to the connectionist architectures. Heuristic fuzzy logic rules and input-output fuzzy membership functions can be optimally tuned from training examples by a hybrid learning scheme comprised of two phases: rule generation phase from data; and rule tuning phase using error backpropagation learning scheme for a neural fuzzy system. To illustrate the performance and applicability of the proposed neuro-fuzzy hybrid model, extensive simulation studies of nonlinear complex dynamic systems are carried out. The proposed method can be applied to an on-line incremental adaptive learning for the prediction and control of nonlinear dynamical systems. Two benchmark case studies are used to demonstrate that the proposed HyFIS system is a superior neuro-fuzzy modelling technique.

  8. Computerized Adaptive Testing System Design: Preliminary Design Considerations.

    DTIC Science & Technology

    1982-07-01

    the administrative or operational requirements of CAT and presented - # k*----.,ku nh-n.-utu (IPOI efi~g.2me (PMU tQ7q. vim NPRDC TR 82-52 July 1982...design model for a computerized adaptive testing ( CAT ) system was developed and presented through a series of hierarchy plus input-process-output (HIPO...physical system was addressed through brief discussions of hardware, software, interfaces, and personnel requirements. Further steps in CAT system

  9. Adaptive feedback synchronization of a unified chaotic system

    NASA Astrophysics Data System (ADS)

    Lu, Junan; Wu, Xiaoqun; Han, Xiuping; Lü, Jinhu

    2004-08-01

    This Letter further improves and extends the work of Wang et al. [Phys. Lett. A 312 (2003) 34]. In detailed, the linear feedback synchronization and adaptive feedback synchronization with only one controller for a unified chaotic system are discussed here. It is noticed that this unified system contains the noted Lorenz and Chen systems. Two chaotic synchronization theorems are attained. Also, numerical simulations are given to show the effectiveness of these methods.

  10. Self-Adaptive System based on Field Programmable Gate Array for Extreme Temperature Electronics

    NASA Technical Reports Server (NTRS)

    Keymeulen, Didier; Zebulum, Ricardo; Rajeshuni, Ramesham; Stoica, Adrian; Katkoori, Srinivas; Graves, Sharon; Novak, Frank; Antill, Charles

    2006-01-01

    In this work, we report the implementation of a self-adaptive system using a field programmable gate array (FPGA) and data converters. The self-adaptive system can autonomously recover the lost functionality of a reconfigurable analog array (RAA) integrated circuit (IC) [3]. Both the RAA IC and the self-adaptive system are operating in extreme temperatures (from 120 C down to -180 C). The RAA IC consists of reconfigurable analog blocks interconnected by several switches and programmable by bias voltages. It implements filters/amplifiers with bandwidth up to 20 MHz. The self-adaptive system controls the RAA IC and is realized on Commercial-Off-The-Shelf (COTS) parts. It implements a basic compensation algorithm that corrects a RAA IC in less than a few milliseconds. Experimental results for the cold temperature environment (down to -180 C) demonstrate the feasibility of this approach.

  11. Adaptive Neural Control of Uncertain MIMO Nonlinear Systems With State and Input Constraints.

    PubMed

    Chen, Ziting; Li, Zhijun; Chen, C L Philip

    2017-06-01

    An adaptive neural control strategy for multiple input multiple output nonlinear systems with various constraints is presented in this paper. To deal with the nonsymmetric input nonlinearity and the constrained states, the proposed adaptive neural control is combined with the backstepping method, radial basis function neural network, barrier Lyapunov function (BLF), and disturbance observer. By ensuring the boundedness of the BLF of the closed-loop system, it is demonstrated that the output tracking is achieved with all states remaining in the constraint sets and the general assumption on nonsingularity of unknown control coefficient matrices has been eliminated. The constructed adaptive neural control has been rigorously proved that it can guarantee the semiglobally uniformly ultimate boundedness of all signals in the closed-loop system. Finally, the simulation studies on a 2-DOF robotic manipulator system indicate that the designed adaptive control is effective.

  12. A Conceptual Framework for Planning Systemic Human Adaptation to Global Warming

    PubMed Central

    Tait, Peter W.; Hanna, Elizabeth G.

    2015-01-01

    Human activity is having multiple, inter-related effects on ecosystems. Greenhouse gas emissions persisting along current trajectories threaten to significantly alter human society. At 0.85 °C of anthropogenic warming, deleterious human impacts are acutely evident. Additional warming of 0.5 °C–1.0 °C from already emitted CO2 will further intensify extreme heat and damaging storm events. Failing to sufficiently address this trend will have a heavy human toll directly and indirectly on health. Along with mitigation efforts, societal adaptation to a warmer world is imperative. Adaptation efforts need to be significantly upscaled to prepare society to lessen the public health effects of rising temperatures. Modifying societal behaviour is inherently complex and presents a major policy challenge. We propose a social systems framework for conceptualizing adaptation that maps out three domains within the adaptation policy landscape: acclimatisation, behavioural adaptation and technological adaptation, which operate at societal and personal levels. We propose that overlaying this framework on a systems approach to societal change planning methods will enhance governments’ capacity and efficacy in strategic planning for adaptation. This conceptual framework provides a policy oriented planning assessment tool that will help planners match interventions to the behaviours being targeted for change. We provide illustrative examples to demonstrate the framework’s application as a planning tool. PMID:26334285

  13. Social networks as embedded complex adaptive systems.

    PubMed

    Benham-Hutchins, Marge; Clancy, Thomas R

    2010-09-01

    As systems evolve over time, their natural tendency is to become increasingly more complex. Studies in the field of complex systems have generated new perspectives on management in social organizations such as hospitals. Much of this research appears as a natural extension of the cross-disciplinary field of systems theory. This is the 15th in a series of articles applying complex systems science to the traditional management concepts of planning, organizing, directing, coordinating, and controlling. In this article, the authors discuss healthcare social networks as a hierarchy of embedded complex adaptive systems. The authors further examine the use of social network analysis tools as a means to understand complex communication patterns and reduce medical errors.

  14. Conceptual design for a user-friendly adaptive optics system at Lick Observatory

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bissinger, H.D.; Olivier, S.; Max, C.

    1996-03-08

    In this paper, we present a conceptual design for a general-purpose adaptive optics system, usable with all Cassegrain facility instruments on the 3 meter Shane telescope at the University of California`s Lick Observatory located on Mt. Hamilton near San Jose, California. The overall design goal for this system is to take the sodium-layer laser guide star adaptive optics technology out of the demonstration stage and to build a user-friendly astronomical tool. The emphasis will be on ease of calibration, improved stability and operational simplicity in order to allow the system to be run routinely by observatory staff. A prototype adaptivemore » optics system and a 20 watt sodium-layer laser guide star system have already been built at Lawrence Livermore National Laboratory for use at Lick Observatory. The design presented in this paper is for a next- generation adaptive optics system that extends the capabilities of the prototype system into the visible with more degrees of freedom. When coupled with a laser guide star system that is upgraded to a power matching the new adaptive optics system, the combined system will produce diffraction-limited images for near-IR cameras. Atmospheric correction at wavelengths of 0.6-1 mm will significantly increase the throughput of the most heavily used facility instrument at Lick, the Kast Spectrograph, and will allow it to operate with smaller slit widths and deeper limiting magnitudes. 8 refs., 2 figs.« less

  15. Multichannel-Hadamard calibration of high-order adaptive optics systems.

    PubMed

    Guo, Youming; Rao, Changhui; Bao, Hua; Zhang, Ang; Zhang, Xuejun; Wei, Kai

    2014-06-02

    we present a novel technique of calibrating the interaction matrix for high-order adaptive optics systems, called the multichannel-Hadamard method. In this method, the deformable mirror actuators are firstly divided into a series of channels according to their coupling relationship, and then the voltage-oriented Hadamard method is applied to these channels. Taking the 595-element adaptive optics system as an example, the procedure is described in detail. The optimal channel dividing is discussed and tested by numerical simulation. The proposed method is also compared with the voltage-oriented Hadamard only method and the multichannel only method by experiments. Results show that the multichannel-Hadamard method can produce significant improvement on interaction matrix measurement.

  16. A Model of Internal Communication in Adaptive Communication Systems.

    ERIC Educational Resources Information Center

    Williams, M. Lee

    A study identified and categorized different types of internal communication systems and developed an applied model of internal communication in adaptive organizational systems. Twenty-one large organizations were selected for their varied missions and diverse approaches to managing internal communication. Individual face-to-face or telephone…

  17. Simulated lumped-parameter system reduced-order adaptive control studies

    NASA Technical Reports Server (NTRS)

    Johnson, C. R., Jr.; Lawrence, D. A.; Taylor, T.; Malakooti, M. V.

    1981-01-01

    Two methods of interpreting the misbehavior of reduced order adaptive controllers are discussed. The first method is based on system input-output description and the second is based on state variable description. The implementation of the single input, single output, autoregressive, moving average system is considered.

  18. Predicting Adaptive Behavior in the Environment from Central Nervous System Dynamics

    PubMed Central

    Proekt, Alex; Wong, Jane; Zhurov, Yuriy; Kozlova, Nataliya; Weiss, Klaudiusz R.; Brezina, Vladimir

    2008-01-01

    To generate adaptive behavior, the nervous system is coupled to the environment. The coupling constrains the dynamical properties that the nervous system and the environment must have relative to each other if adaptive behavior is to be produced. In previous computational studies, such constraints have been used to evolve controllers or artificial agents to perform a behavioral task in a given environment. Often, however, we already know the controller, the real nervous system, and its dynamics. Here we propose that the constraints can also be used to solve the inverse problem—to predict from the dynamics of the nervous system the environment to which they are adapted, and so reconstruct the production of the adaptive behavior by the entire coupled system. We illustrate how this can be done in the feeding system of the sea slug Aplysia. At the core of this system is a central pattern generator (CPG) that, with dynamics on both fast and slow time scales, integrates incoming sensory stimuli to produce ingestive and egestive motor programs. We run models embodying these CPG dynamics—in effect, autonomous Aplysia agents—in various feeding environments and analyze the performance of the entire system in a realistic feeding task. We find that the dynamics of the system are tuned for optimal performance in a narrow range of environments that correspond well to those that Aplysia encounter in the wild. In these environments, the slow CPG dynamics implement efficient ingestion of edible seaweed strips with minimal sensory information about them. The fast dynamics then implement a switch to a different behavioral mode in which the system ignores the sensory information completely and follows an internal “goal,” emergent from the dynamics, to egest again a strip that proves to be inedible. Key predictions of this reconstruction are confirmed in real feeding animals. PMID:18989362

  19. Adaptive infrared-reflecting systems inspired by cephalopods

    NASA Astrophysics Data System (ADS)

    Xu, Chengyi; Stiubianu, George T.; Gorodetsky, Alon A.

    2018-03-01

    Materials and systems that statically reflect radiation in the infrared region of the electromagnetic spectrum underpin the performance of many entrenched technologies, including building insulation, energy-conserving windows, spacecraft components, electronics shielding, container packaging, protective clothing, and camouflage platforms. The development of their adaptive variants, in which the infrared-reflecting properties dynamically change in response to external stimuli, has emerged as an important unmet scientific challenge. By drawing inspiration from cephalopod skin, we developed adaptive infrared-reflecting platforms that feature a simple actuation mechanism, low working temperature, tunable spectral range, weak angular dependence, fast response, stability to repeated cycling, amenability to patterning and multiplexing, autonomous operation, robust mechanical properties, and straightforward manufacturability. Our findings may open opportunities for infrared camouflage and other technologies that regulate infrared radiation.

  20. DKIST Adaptive Optics System: Simulation Results

    NASA Astrophysics Data System (ADS)

    Marino, Jose; Schmidt, Dirk

    2016-05-01

    The 4 m class Daniel K. Inouye Solar Telescope (DKIST), currently under construction, will be equipped with an ultra high order solar adaptive optics (AO) system. The requirements and capabilities of such a solar AO system are beyond those of any other solar AO system currently in operation. We must rely on solar AO simulations to estimate and quantify its performance.We present performance estimation results of the DKIST AO system obtained with a new solar AO simulation tool. This simulation tool is a flexible and fast end-to-end solar AO simulator which produces accurate solar AO simulations while taking advantage of current multi-core computer technology. It relies on full imaging simulations of the extended field Shack-Hartmann wavefront sensor (WFS), which directly includes important secondary effects such as field dependent distortions and varying contrast of the WFS sub-aperture images.

  1. The plasma membrane transport systems and adaptation to salinity.

    PubMed

    Mansour, Mohamed Magdy F

    2014-11-15

    Salt stress represents one of the environmental challenges that drastically affect plant growth and yield. Evidence suggests that glycophytes and halophytes have a salt tolerance mechanisms working at the cellular level, and the plasma membrane (PM) is believed to be one facet of the cellular mechanisms. The responses of the PM transport proteins to salinity in contrasting species/cultivars were discussed. The review provides a comprehensive overview of the recent advances describing the crucial roles that the PM transport systems have in plant adaptation to salt. Several lines of evidence were presented to demonstrate the correlation between the PM transport proteins and adaptation of plants to high salinity. How alterations in these transport systems of the PM allow plants to cope with the salt stress was also addressed. Although inconsistencies exist in some of the information related to the responses of the PM transport proteins to salinity in different species/cultivars, their key roles in adaptation of plants to high salinity is obvious and evident, and cannot be precluded. Despite the promising results, detailed investigations at the cellular/molecular level are needed in some issues of the PM transport systems in response to salinity to further evaluate their implication in salt tolerance. Copyright © 2014 Elsevier GmbH. All rights reserved.

  2. A QoS adaptive multimedia transport system: design, implementation and experiences

    NASA Astrophysics Data System (ADS)

    Campbell, Andrew; Coulson, Geoff

    1997-03-01

    The long awaited `new environment' of high speed broadband networks and multimedia applications is fast becoming a reality. However, few systems in existence today, whether they be large scale pilots or small scale test-beds in research laboratories, offer a fully integrated and flexible environment where multimedia applications can maximally exploit the quality of service (QoS) capabilities of supporting networks and end-systems. In this paper we describe the implementation of an adaptive transport system that incorporates a QoS oriented API and a range of mechanisms to assist applications in exploiting QoS and adapting to fluctuations in QoS. The system, which is an instantiation of the Lancaster QoS Architecture, is implemented in a multi ATM switch network environment with Linux based PC end systems and continuous media file servers. A performance evaluation of the system configured to support video-on-demand application scenario is presented and discussed. Emphasis is placed on novel features of the system and on their integration into a complete prototype. The most prominent novelty of our design is a `distributed QoS adaptation' scheme which allows applications to delegate to the system responsibility for augmenting and reducing the perceptual quality of video and audio flows when resource availability increases or decreases.

  3. A full XML-based approach to creating hypermedia learning modules in web-based environments: application to a pathology course.

    PubMed

    Staccini, Pascal; Dufour, Jean -Charles; Joubert, Michel; Michiels, Jean -François; Fieschi, Marius

    2003-01-01

    Nowadays, web-based learning services are a key topic in the pedagogical and learning strategies of universities. While organisational and teaching requirements of the learning environment are being evaluated, technical specifications are emerging, enabling educators to build advanced "units of learning". Changes, however, take a long time and cost-effective solutions have to be found to involve our institutions in such actions. In this paper, we present a model of the components of a course. We detail the method followed to implement this model in hypermedia modules with a viewer that can be played on line or from a CD-ROM. The XML technology has been used to implement all the data structures and a client-side architecture has been designed to build a course viewer. Standards of description of content (such as Dublin Core and DocBook) have been integrated into the data structures. This tool has been populated with data from a pathology course and supports other medical contents. The choice of the architecture and the usefulness of the programming tools are discussed. The means of migrating towards a server-side application are presented.

  4. Cluster formation by allelomimesis in real-world complex adaptive systems

    NASA Astrophysics Data System (ADS)

    Juanico, Dranreb Earl; Monterola, Christopher; Saloma, Caesar

    2005-04-01

    Animal and human clusters are complex adaptive systems and many organize in cluster sizes s that obey the frequency distribution D(s)∝s-τ . The exponent τ describes the relative abundance of the cluster sizes in a given system. Data analyses reveal that real-world clusters exhibit a broad spectrum of τ values, 0.7 (tuna fish schools) ⩽τ⩽4.61 (T4 bacteriophage gene family sizes). Allelomimesis is proposed as an underlying mechanism for adaptation that explains the observed broad τ spectrum. Allelomimesis is the tendency of an individual to imitate the actions of others and two cluster systems have different τ values when their component agents display unequal degrees of allelomimetic tendencies. Cluster formation by allelomimesis is shown to be of three general types: namely, blind copying, information-use copying, and noncopying. Allelomimetic adaptation also reveals that the most stable cluster size is formed by three strongly allelomimetic individuals. Our finding is consistent with available field data taken from killer whales and marmots.

  5. The Study and Design of Adaptive Learning System Based on Fuzzy Set Theory

    NASA Astrophysics Data System (ADS)

    Jia, Bing; Zhong, Shaochun; Zheng, Tianyang; Liu, Zhiyong

    Adaptive learning is an effective way to improve the learning outcomes, that is, the selection of learning content and presentation should be adapted to each learner's learning context, learning levels and learning ability. Adaptive Learning System (ALS) can provide effective support for adaptive learning. This paper proposes a new ALS based on fuzzy set theory. It can effectively estimate the learner's knowledge level by test according to learner's target. Then take the factors of learner's cognitive ability and preference into consideration to achieve self-organization and push plan of knowledge. This paper focuses on the design and implementation of domain model and user model in ALS. Experiments confirmed that the system providing adaptive content can effectively help learners to memory the content and improve their comprehension.

  6. Developing the evidence base for mainstreaming adaptation of stormwater systems to climate change.

    PubMed

    Gersonius, B; Nasruddin, F; Ashley, R; Jeuken, A; Pathirana, A; Zevenbergen, C

    2012-12-15

    In a context of high uncertainty about hydro-climatic variables, the development of updated methods for climate impact and adaptation assessment is as important, if not more important than the provision of improved climate change data. In this paper, we introduce a hybrid method to facilitate mainstreaming adaptation of stormwater systems to climate change: i.e., the Mainstreaming method. The Mainstreaming method starts with an analysis of adaptation tipping points (ATPs), which is effect-based. These are points of reference where the magnitude of climate change is such that acceptable technical, environmental, societal or economic standards may be compromised. It extends the ATP analysis to include aspects from a bottom-up approach. The extension concerns the analysis of adaptation opportunities in the stormwater system. The results from both analyses are then used in combination to identify and exploit Adaptation Mainstreaming Moments (AMMs). Use of this method will enhance the understanding of the adaptive potential of stormwater systems. We have applied the proposed hybrid method to the management of flood risk for an urban stormwater system in Dordrecht (the Netherlands). The main finding of this case study is that the application of the Mainstreaming method helps to increase the no-/low-regret character of adaptation for several reasons: it focuses the attention on the most urgent effects of climate change; it is expected to lead to potential cost reductions, since adaptation options can be integrated into infrastructure and building design at an early stage instead of being applied separately; it will lead to the development of area-specific responses, which could not have been developed on a higher scale level; it makes it possible to take account of local values and sensibilities, which contributes to increased public and political support for the adaptive strategies. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. GUIELOA: Adaptive Optics System for the 2.1-m SPM UNAM Telescope

    NASA Astrophysics Data System (ADS)

    Cuevas, S.; Iriarte, A.; Martínez, L. A.; Garfias, F.; Sánchez, L.; Chapa, O.; Ruelas, R. A.

    2004-08-01

    GUIELOA is the adaptive optics system project for the 2.1-m SPM telescope. This is a 19 sub-apertures curvature-type system. It corrects 8 Zernike terms. GUIELOA is very similar to PUEO, the CFHT adaptive optics system and compensates the atmospheric turbulence from the R band to the K band. Among the planned applications of GUIELOA are the study of OB binary systems, the detection of close binary stars, and the study of disks, jets and other phenomena associated with young stars.

  8. Transformational adaptation when incremental adaptations to climate change are insufficient

    PubMed Central

    Kates, Robert W.; Travis, William R.; Wilbanks, Thomas J.

    2012-01-01

    All human–environment systems adapt to climate and its natural variation. Adaptation to human-induced change in climate has largely been envisioned as increments of these adaptations intended to avoid disruptions of systems at their current locations. In some places, for some systems, however, vulnerabilities and risks may be so sizeable that they require transformational rather than incremental adaptations. Three classes of transformational adaptations are those that are adopted at a much larger scale, that are truly new to a particular region or resource system, and that transform places and shift locations. We illustrate these with examples drawn from Africa, Europe, and North America. Two conditions set the stage for transformational adaptation to climate change: large vulnerability in certain regions, populations, or resource systems; and severe climate change that overwhelms even robust human use systems. However, anticipatory transformational adaptation may be difficult to implement because of uncertainties about climate change risks and adaptation benefits, the high costs of transformational actions, and institutional and behavioral actions that tend to maintain existing resource systems and policies. Implementing transformational adaptation requires effort to initiate it and then to sustain the effort over time. In initiating transformational adaptation focusing events and multiple stresses are important, combined with local leadership. In sustaining transformational adaptation, it seems likely that supportive social contexts and the availability of acceptable options and resources for actions are key enabling factors. Early steps would include incorporating transformation adaptation into risk management and initiating research to expand the menu of innovative transformational adaptations. PMID:22509036

  9. Transformational adaptation when incremental adaptations to climate change are insufficient.

    PubMed

    Kates, Robert W; Travis, William R; Wilbanks, Thomas J

    2012-05-08

    All human-environment systems adapt to climate and its natural variation. Adaptation to human-induced change in climate has largely been envisioned as increments of these adaptations intended to avoid disruptions of systems at their current locations. In some places, for some systems, however, vulnerabilities and risks may be so sizeable that they require transformational rather than incremental adaptations. Three classes of transformational adaptations are those that are adopted at a much larger scale, that are truly new to a particular region or resource system, and that transform places and shift locations. We illustrate these with examples drawn from Africa, Europe, and North America. Two conditions set the stage for transformational adaptation to climate change: large vulnerability in certain regions, populations, or resource systems; and severe climate change that overwhelms even robust human use systems. However, anticipatory transformational adaptation may be difficult to implement because of uncertainties about climate change risks and adaptation benefits, the high costs of transformational actions, and institutional and behavioral actions that tend to maintain existing resource systems and policies. Implementing transformational adaptation requires effort to initiate it and then to sustain the effort over time. In initiating transformational adaptation focusing events and multiple stresses are important, combined with local leadership. In sustaining transformational adaptation, it seems likely that supportive social contexts and the availability of acceptable options and resources for actions are key enabling factors. Early steps would include incorporating transformation adaptation into risk management and initiating research to expand the menu of innovative transformational adaptations.

  10. Algebraic and adaptive learning in neural control systems

    NASA Astrophysics Data System (ADS)

    Ferrari, Silvia

    A systematic approach is developed for designing adaptive and reconfigurable nonlinear control systems that are applicable to plants modeled by ordinary differential equations. The nonlinear controller comprising a network of neural networks is taught using a two-phase learning procedure realized through novel techniques for initialization, on-line training, and adaptive critic design. A critical observation is that the gradients of the functions defined by the neural networks must equal corresponding linear gain matrices at chosen operating points. On-line training is based on a dual heuristic adaptive critic architecture that improves control for large, coupled motions by accounting for actual plant dynamics and nonlinear effects. An action network computes the optimal control law; a critic network predicts the derivative of the cost-to-go with respect to the state. Both networks are algebraically initialized based on prior knowledge of satisfactory pointwise linear controllers and continue to adapt on line during full-scale simulations of the plant. On-line training takes place sequentially over discrete periods of time and involves several numerical procedures. A backpropagating algorithm called Resilient Backpropagation is modified and successfully implemented to meet these objectives, without excessive computational expense. This adaptive controller is as conservative as the linear designs and as effective as a global nonlinear controller. The method is successfully implemented for the full-envelope control of a six-degree-of-freedom aircraft simulation. The results show that the on-line adaptation brings about improved performance with respect to the initialization phase during aircraft maneuvers that involve large-angle and coupled dynamics, and parameter variations.

  11. Model-Based Adaptive Event-Triggered Control of Strict-Feedback Nonlinear Systems.

    PubMed

    Li, Yuan-Xin; Yang, Guang-Hong

    2018-04-01

    This paper is concerned with the adaptive event-triggered control problem of nonlinear continuous-time systems in strict-feedback form. By using the event-sampled neural network (NN) to approximate the unknown nonlinear function, an adaptive model and an associated event-triggered controller are designed by exploiting the backstepping method. In the proposed method, the feedback signals and the NN weights are aperiodically updated only when the event-triggered condition is violated. A positive lower bound on the minimum intersample time is guaranteed to avoid accumulation point. The closed-loop stability of the resulting nonlinear impulsive dynamical system is rigorously proved via Lyapunov analysis under an adaptive event sampling condition. In comparing with the traditional adaptive backstepping design with a fixed sample period, the event-triggered method samples the state and updates the NN weights only when it is necessary. Therefore, the number of transmissions can be significantly reduced. Finally, two simulation examples are presented to show the effectiveness of the proposed control method.

  12. 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.

  13. Simple adaptive control system design for a quadrotor with an internal PFC

    NASA Astrophysics Data System (ADS)

    Mizumoto, Ikuro; Nakamura, Takuto; Kumon, Makoto; Takagi, Taro

    2014-12-01

    The paper deals with an adaptive control system design problem for a four rotor helicopter or quadrotor. A simple adaptive control design scheme with a parallel feedforward compensator (PFC) in the internal loop of the considered quadrotor will be proposed based on the backstepping strategy. As is well known, the backstepping control strategy is one of the advanced control strategy for nonlinear systems. However, the control algorithm will become complex if the system has higher order relative degrees. We will show that one can skip some design steps of the backstepping method by introducing a PFC in the inner loop of the considered quadrotor, so that the structure of the obtained controller will be simplified and a high gain based adaptive feedback control system will be designed. The effectiveness of the proposed method will be confirmed through numerical simulations.

  14. Adaptive tracking control for a class of stochastic switched systems

    NASA Astrophysics Data System (ADS)

    Zhang, Hui; Xia, Yuanqing

    2018-02-01

    The problem of adaptive tracking is considered for a class of stochastic switched systems, in this paper. As preliminaries, the criterion of global asymptotical practical stability in probability is first presented by the aid of common Lyapunov function method. Based on the Lyapunov stability criterion, adaptive backstepping controllers are designed to guarantee that the closed-loop system has a unique global solution, which is globally asymptotically practically stable in probability, and the tracking error in the fourth moment converges to an arbitrarily small neighbourhood of zero. Simulation examples are given to demonstrate the efficiency of the proposed schemes.

  15. Adaptive control of nonlinear uncertain active suspension systems with prescribed performance.

    PubMed

    Huang, Yingbo; Na, Jing; Wu, Xing; Liu, Xiaoqin; Guo, Yu

    2015-01-01

    This paper proposes adaptive control designs for vehicle active suspension systems with unknown nonlinear dynamics (e.g., nonlinear spring and piece-wise linear damper dynamics). An adaptive control is first proposed to stabilize the vertical vehicle displacement and thus to improve the ride comfort and to guarantee other suspension requirements (e.g., road holding and suspension space limitation) concerning the vehicle safety and mechanical constraints. An augmented neural network is developed to online compensate for the unknown nonlinearities, and a novel adaptive law is developed to estimate both NN weights and uncertain model parameters (e.g., sprung mass), where the parameter estimation error is used as a leakage term superimposed on the classical adaptations. To further improve the control performance and simplify the parameter tuning, a prescribed performance function (PPF) characterizing the error convergence rate, maximum overshoot and steady-state error is used to propose another adaptive control. The stability for the closed-loop system is proved and particular performance requirements are analyzed. Simulations are included to illustrate the effectiveness of the proposed control schemes. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

  16. Decomposed fuzzy systems and their application in direct adaptive fuzzy control.

    PubMed

    Hsueh, Yao-Chu; Su, Shun-Feng; Chen, Ming-Chang

    2014-10-01

    In this paper, a novel fuzzy structure termed as the decomposed fuzzy system (DFS) is proposed to act as the fuzzy approximator for adaptive fuzzy control systems. The proposed structure is to decompose each fuzzy variable into layers of fuzzy systems, and each layer is to characterize one traditional fuzzy set. Similar to forming fuzzy rules in traditional fuzzy systems, layers from different variables form the so-called component fuzzy systems. DFS is proposed to provide more adjustable parameters to facilitate possible adaptation in fuzzy rules, but without introducing a learning burden. It is because those component fuzzy systems are independent so that it can facilitate minimum distribution learning effects among component fuzzy systems. It can be seen from our experiments that even when the rule number increases, the learning time in terms of cycles is still almost constant. It can also be found that the function approximation capability and learning efficiency of the DFS are much better than that of the traditional fuzzy systems when employed in adaptive fuzzy control systems. Besides, in order to further reduce the computational burden, a simplified DFS is proposed in this paper to satisfy possible real time constraints required in many applications. From our simulation results, it can be seen that the simplified DFS can perform fairly with a more concise decomposition structure.

  17. Challenges in adapting existing clinical natural language processing systems to multiple, diverse health care settings.

    PubMed

    Carrell, David S; Schoen, Robert E; Leffler, Daniel A; Morris, Michele; Rose, Sherri; Baer, Andrew; Crockett, Seth D; Gourevitch, Rebecca A; Dean, Katie M; Mehrotra, Ateev

    2017-09-01

    Widespread application of clinical natural language processing (NLP) systems requires taking existing NLP systems and adapting them to diverse and heterogeneous settings. We describe the challenges faced and lessons learned in adapting an existing NLP system for measuring colonoscopy quality. Colonoscopy and pathology reports from 4 settings during 2013-2015, varying by geographic location, practice type, compensation structure, and electronic health record. Though successful, adaptation required considerably more time and effort than anticipated. Typical NLP challenges in assembling corpora, diverse report structures, and idiosyncratic linguistic content were greatly magnified. Strategies for addressing adaptation challenges include assessing site-specific diversity, setting realistic timelines, leveraging local electronic health record expertise, and undertaking extensive iterative development. More research is needed on how to make it easier to adapt NLP systems to new clinical settings. A key challenge in widespread application of NLP is adapting existing systems to new clinical settings. © The Author 2017. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  18. Adaptive optics system performance approximations for atmospheric turbulence correction

    NASA Astrophysics Data System (ADS)

    Tyson, Robert K.

    1990-10-01

    Analysis of adaptive optics system behavior often can be reduced to a few approximations and scaling laws. For atmospheric turbulence correction, the deformable mirror (DM) fitting error is most often used to determine a priori the interactuator spacing and the total number of correction zones required. This paper examines the mirror fitting error in terms of its most commonly used exponential form. The explicit constant in the error term is dependent on deformable mirror influence function shape and actuator geometry. The method of least squares fitting of discrete influence functions to the turbulent wavefront is compared to the linear spatial filtering approximation of system performance. It is found that the spatial filtering method overstimates the correctability of the adaptive optics system by a small amount. By evaluating fitting error for a number of DM configurations, actuator geometries, and influence functions, fitting error constants verify some earlier investigations.

  19. Adaptable data management for systems biology investigations.

    PubMed

    Boyle, John; Rovira, Hector; Cavnor, Chris; Burdick, David; Killcoyne, Sarah; Shmulevich, Ilya

    2009-03-06

    Within research each experiment is different, the focus changes and the data is generated from a continually evolving barrage of technologies. There is a continual introduction of new techniques whose usage ranges from in-house protocols through to high-throughput instrumentation. To support these requirements data management systems are needed that can be rapidly built and readily adapted for new usage. The adaptable data management system discussed is designed to support the seamless mining and analysis of biological experiment data that is commonly used in systems biology (e.g. ChIP-chip, gene expression, proteomics, imaging, flow cytometry). We use different content graphs to represent different views upon the data. These views are designed for different roles: equipment specific views are used to gather instrumentation information; data processing oriented views are provided to enable the rapid development of analysis applications; and research project specific views are used to organize information for individual research experiments. This management system allows for both the rapid introduction of new types of information and the evolution of the knowledge it represents. Data management is an important aspect of any research enterprise. It is the foundation on which most applications are built, and must be easily extended to serve new functionality for new scientific areas. We have found that adopting a three-tier architecture for data management, built around distributed standardized content repositories, allows us to rapidly develop new applications to support a diverse user community.

  20. Adaptable data management for systems biology investigations

    PubMed Central

    Boyle, John; Rovira, Hector; Cavnor, Chris; Burdick, David; Killcoyne, Sarah; Shmulevich, Ilya

    2009-01-01

    Background Within research each experiment is different, the focus changes and the data is generated from a continually evolving barrage of technologies. There is a continual introduction of new techniques whose usage ranges from in-house protocols through to high-throughput instrumentation. To support these requirements data management systems are needed that can be rapidly built and readily adapted for new usage. Results The adaptable data management system discussed is designed to support the seamless mining and analysis of biological experiment data that is commonly used in systems biology (e.g. ChIP-chip, gene expression, proteomics, imaging, flow cytometry). We use different content graphs to represent different views upon the data. These views are designed for different roles: equipment specific views are used to gather instrumentation information; data processing oriented views are provided to enable the rapid development of analysis applications; and research project specific views are used to organize information for individual research experiments. This management system allows for both the rapid introduction of new types of information and the evolution of the knowledge it represents. Conclusion Data management is an important aspect of any research enterprise. It is the foundation on which most applications are built, and must be easily extended to serve new functionality for new scientific areas. We have found that adopting a three-tier architecture for data management, built around distributed standardized content repositories, allows us to rapidly develop new applications to support a diverse user community. PMID:19265554

  1. A Multimedia Adaptive Tutoring System for Mathematics That Addresses Cognition, Metacognition and Affect

    ERIC Educational Resources Information Center

    Arroyo, Ivon; Woolf, Beverly Park; Burelson, Winslow; Muldner, Kasia; Rai, Dovan; Tai, Minghui

    2014-01-01

    This article describes research results based on multiple years of experimentation and real-world experience with an adaptive tutoring system named Wayang Outpost. The system represents a novel adaptive learning technology that has shown successful outcomes with thousands of students, and provided teachers with valuable information about students'…

  2. Adaptivity in Educational Systems for Language Learning: A Review

    ERIC Educational Resources Information Center

    Slavuj, Vanja; Meštrovic, Ana; Kovacic, Božidar

    2017-01-01

    Adaptive and intelligent instructional systems are used to deal with the issue of learning personalisation in contexts where human instructors are not immediately available, so their role is transferred entirely or in part onto the computer. Even though such systems are mostly developed for well-defined domains that have a rather straightforward…

  3. TEJAS - TELEROBOTICS/EVA JOINT ANALYSIS SYSTEM VERSION 1.0

    NASA Technical Reports Server (NTRS)

    Drews, M. L.

    1994-01-01

    The primary objective of space telerobotics as a research discipline is the augmentation and/or support of extravehicular activity (EVA) with telerobotic activity; this allows increased emplacement of on-orbit assets while providing for their "in situ" management. Development of the requisite telerobot work system requires a well-understood correspondence between EVA and telerobotics that to date has been only partially established. The Telerobotics/EVA Joint Analysis Systems (TEJAS) hypermedia information system uses object-oriented programming to bridge the gap between crew-EVA and telerobotics activities. TEJAS Version 1.0 contains twenty HyperCard stacks that use a visual, customizable interface of icon buttons, pop-up menus, and relational commands to store, link, and standardize related information about the primitives, technologies, tasks, assumptions, and open issues involved in space telerobot or crew EVA tasks. These stacks are meant to be interactive and can be used with any database system running on a Macintosh, including spreadsheets, relational databases, word-processed documents, and hypermedia utilities. The software provides a means for managing volumes of data and for communicating complex ideas, relationships, and processes inherent to task planning. The stack system contains 3MB of data and utilities to aid referencing, discussion, communication, and analysis within the EVA and telerobotics communities. The six baseline analysis stacks (EVATasks, EVAAssume, EVAIssues, TeleTasks, TeleAssume, and TeleIssues) work interactively to manage and relate basic information which you enter about the crew-EVA and telerobot tasks you wish to analyze in depth. Analysis stacks draw on information in the Reference stacks as part of a rapid point-and-click utility for building scripts of specific task primitives or for any EVA or telerobotics task. Any or all of these stacks can be completely incorporated within other hypermedia applications, or they can be

  4. Adaptive control for eye-gaze input system

    NASA Astrophysics Data System (ADS)

    Zhao, Qijie; Tu, Dawei; Yin, Hairong

    2004-01-01

    The characteristics of the vision-based human-computer interaction system have been analyzed, and the practical application and its limited factors at present time have also been mentioned. The information process methods have been put forward. In order to make the communication flexible and spontaneous, the algorithms to adaptive control of user"s head movement has been designed, and the events-based methods and object-oriented computer language is used to develop the system software, by experiment testing, we found that under given condition, these methods and algorithms can meet the need of the HCI.

  5. Calibrated Methodology for Assessing Adaptation Costs for Urban Drainage Systems

    EPA Science Inventory

    Changes in precipitation patterns associated with climate change may pose significant challenges for storm water management systems across much of the U.S. In particular, adapting these systems to more intense rainfall events will require significant investment. The assessment ...

  6. Materials learning from life: concepts for active, adaptive and autonomous molecular systems.

    PubMed

    Merindol, Rémi; Walther, Andreas

    2017-09-18

    Bioinspired out-of-equilibrium systems will set the scene for the next generation of molecular materials with active, adaptive, autonomous, emergent and intelligent behavior. Indeed life provides the best demonstrations of complex and functional out-of-equilibrium systems: cells keep track of time, communicate, move, adapt, evolve and replicate continuously. Stirred by the understanding of biological principles, artificial out-of-equilibrium systems are emerging in many fields of soft matter science. Here we put in perspective the molecular mechanisms driving biological functions with the ones driving synthetic molecular systems. Focusing on principles that enable new levels of functionalities (temporal control, autonomous structures, motion and work generation, information processing) rather than on specific material classes, we outline key cross-disciplinary concepts that emerge in this challenging field. Ultimately, the goal is to inspire and support new generations of autonomous and adaptive molecular devices fueled by self-regulating chemistry.

  7. Adaptive Fuzzy Output Feedback Control for Switched Nonlinear Systems With Unmodeled Dynamics.

    PubMed

    Tong, Shaocheng; Li, Yongming

    2017-02-01

    This paper investigates a robust adaptive fuzzy control stabilization problem for a class of uncertain nonlinear systems with arbitrary switching signals that use an observer-based output feedback scheme. The considered switched nonlinear systems possess the unstructured uncertainties, unmodeled dynamics, and without requiring the states being available for measurement. A state observer which is independent of switching signals is designed to solve the problem of unmeasured states. Fuzzy logic systems are used to identify unknown lumped nonlinear functions so that the problem of unstructured uncertainties can be solved. By combining adaptive backstepping design principle and small-gain approach, a novel robust adaptive fuzzy output feedback stabilization control approach is developed. The stability of the closed-loop system is proved via the common Lyapunov function theory and small-gain theorem. Finally, the simulation results are given to demonstrate the validity and performance of the proposed control strategy.

  8. Simple adaptive control system design for a quadrotor with an internal PFC

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mizumoto, Ikuro; Nakamura, Takuto; Kumon, Makoto

    2014-12-10

    The paper deals with an adaptive control system design problem for a four rotor helicopter or quadrotor. A simple adaptive control design scheme with a parallel feedforward compensator (PFC) in the internal loop of the considered quadrotor will be proposed based on the backstepping strategy. As is well known, the backstepping control strategy is one of the advanced control strategy for nonlinear systems. However, the control algorithm will become complex if the system has higher order relative degrees. We will show that one can skip some design steps of the backstepping method by introducing a PFC in the inner loopmore » of the considered quadrotor, so that the structure of the obtained controller will be simplified and a high gain based adaptive feedback control system will be designed. The effectiveness of the proposed method will be confirmed through numerical simulations.« less

  9. Approximately adaptive neural cooperative control for nonlinear multiagent systems with performance guarantee

    NASA Astrophysics Data System (ADS)

    Wang, Jing; Yang, Tianyu; Staskevich, Gennady; Abbe, Brian

    2017-04-01

    This paper studies the cooperative control problem for a class of multiagent dynamical systems with partially unknown nonlinear system dynamics. In particular, the control objective is to solve the state consensus problem for multiagent systems based on the minimisation of certain cost functions for individual agents. Under the assumption that there exist admissible cooperative controls for such class of multiagent systems, the formulated problem is solved through finding the optimal cooperative control using the approximate dynamic programming and reinforcement learning approach. With the aid of neural network parameterisation and online adaptive learning, our method renders a practically implementable approximately adaptive neural cooperative control for multiagent systems. Specifically, based on the Bellman's principle of optimality, the Hamilton-Jacobi-Bellman (HJB) equation for multiagent systems is first derived. We then propose an approximately adaptive policy iteration algorithm for multiagent cooperative control based on neural network approximation of the value functions. The convergence of the proposed algorithm is rigorously proved using the contraction mapping method. The simulation results are included to validate the effectiveness of the proposed algorithm.

  10. Water System Adaptation To Hydrological Changes: Module 5, Water Quality and Infrastructure Response to Rapid Urbanization: Adaptation Case Study in China

    EPA Science Inventory

    This course will introduce students to the fundamental principles of water system adaptation to hydrological changes, with emphasis on data analysis and interpretation, technical planning, and computational modeling. Starting with real-world scenarios and adaptation needs, the co...

  11. People at the centre of complex adaptive health systems reform.

    PubMed

    Sturmberg, Joachim P; O'Halloran, Diana M; Martin, Carmel M

    2010-10-18

    Health systems are increasingly recognised to be complex adaptive systems (CASs), functionally characterised by their continuing and dynamic adaptation in response to core system drivers, or attractors. The core driver for our health system (and for the health reform strategies intended to achieve it) should clearly be the improvement of people's health - the personal experience of health, regardless of organic abnormalities; we contend that a patient-centred health system requires flexible localised decision making and resource use. The prevailing trend is to use disease protocols, financial management strategies and centralised control of siloed programs to manage our health system. This strategy is suggested to be fatally flawed, as: people's health and health experience as core system drivers are inevitably pre-empted by centralised and standardised strategies; the context specificity of personal experience and the capacity of local systems are overlooked; and in line with CAS patterns and characteristics, these strategies will lead to "unintended" consequences on all parts of the system. In Australia, there is still the time and opportunity for health system redesign that truly places people and their health at the core of the system.

  12. The dynamics of health care reform--learning from a complex adaptive systems theoretical perspective.

    PubMed

    Sturmberg, Joachim P; Martin, Carmel M

    2010-10-01

    Health services demonstrate key features of complex adaptive systems (CAS), they are dynamic and unfold in unpredictable ways, and unfolding events are often unique. To better understand the complex adaptive nature of health systems around a core attractor we propose the metaphor of the health care vortex. We also suggest that in an ideal health care system the core attractor would be personal health attainment. Health care reforms around the world offer an opportunity to analyse health system change from a complex adaptive perspective. At large health care reforms have been pursued disregarding the complex adaptive nature of the health system. The paper details some recent reforms and outlines how to understand their strategies and outcomes, and what could be learnt for future efforts, utilising CAS principles. Current health systems show the inherent properties of a CAS driven by a core attractor of disease and cost containment. We content that more meaningful health systems reform requires the delicate task of shifting the core attractor from disease and cost containment towards health attainment.

  13. CRISPR-Cas systems: prokaryotes upgrade to adaptive immunity

    PubMed Central

    Barrangou, Rodolphe; Marraffini, Luciano A.

    2014-01-01

    Summary Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR), and associated proteins (Cas) comprise the CRISPR-Cas system, which confers adaptive immunity against exogenic elements in many bacteria and most archaea. CRISPR-mediated immunization occurs through the uptake of DNA from invasive genetic elements such as plasmids and viruses, followed by its integration into CRISPR loci. These loci are subsequently transcribed and processed into small interfering RNAs that guide nucleases for specific cleavage of complementary sequences. Conceptually, CRISPR-Cas shares functional features with the mammalian adaptive immune system, while also exhibiting characteristics of Lamarckian evolution. Because immune markers spliced from exogenous agents are integrated iteratively in CRISPR loci, they constitute a genetic record of vaccination events and reflect environmental conditions and changes over time. Cas endonucleases, which can be reprogrammed by small guide RNAs have shown unprecedented potential and flexibility for genome editing, and can be repurposed for numerous DNA targeting applications including transcriptional control. PMID:24766887

  14. CRISPR-Cas systems: Prokaryotes upgrade to adaptive immunity.

    PubMed

    Barrangou, Rodolphe; Marraffini, Luciano A

    2014-04-24

    Clustered regularly interspaced short palindromic repeats (CRISPR), and associated proteins (Cas) comprise the CRISPR-Cas system, which confers adaptive immunity against exogenic elements in many bacteria and most archaea. CRISPR-mediated immunization occurs through the uptake of DNA from invasive genetic elements such as plasmids and viruses, followed by its integration into CRISPR loci. These loci are subsequently transcribed and processed into small interfering RNAs that guide nucleases for specific cleavage of complementary sequences. Conceptually, CRISPR-Cas shares functional features with the mammalian adaptive immune system, while also exhibiting characteristics of Lamarckian evolution. Because immune markers spliced from exogenous agents are integrated iteratively in CRISPR loci, they constitute a genetic record of vaccination events and reflect environmental conditions and changes over time. Cas endonucleases, which can be reprogrammed by small guide RNAs have shown unprecedented potential and flexibility for genome editing and can be repurposed for numerous DNA targeting applications including transcriptional control. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Neural network-based model reference adaptive control system.

    PubMed

    Patino, H D; Liu, D

    2000-01-01

    In this paper, an approach to model reference adaptive control based on neural networks is proposed and analyzed for a class of first-order continuous-time nonlinear dynamical systems. The controller structure can employ either a radial basis function network or a feedforward neural network to compensate adaptively the nonlinearities in the plant. A stable controller-parameter adjustment mechanism, which is determined using the Lyapunov theory, is constructed using a sigma-modification-type updating law. The evaluation of control error in terms of the neural network learning error is performed. That is, the control error converges asymptotically to a neighborhood of zero, whose size is evaluated and depends on the approximation error of the neural network. In the design and analysis of neural network-based control systems, it is important to take into account the neural network learning error and its influence on the control error of the plant. Simulation results showing the feasibility and performance of the proposed approach are given.

  16. Cross-Layer Adaptive Feedback Scheduling of Wireless Control Systems

    PubMed Central

    Xia, Feng; Ma, Longhua; Peng, Chen; Sun, Youxian; Dong, Jinxiang

    2008-01-01

    There is a trend towards using wireless technologies in networked control systems. However, the adverse properties of the radio channels make it difficult to design and implement control systems in wireless environments. To attack the uncertainty in available communication resources in wireless control systems closed over WLAN, a cross-layer adaptive feedback scheduling (CLAFS) scheme is developed, which takes advantage of the co-design of control and wireless communications. By exploiting cross-layer design, CLAFS adjusts the sampling periods of control systems at the application layer based on information about deadline miss ratio and transmission rate from the physical layer. Within the framework of feedback scheduling, the control performance is maximized through controlling the deadline miss ratio. Key design parameters of the feedback scheduler are adapted to dynamic changes in the channel condition. An event-driven invocation mechanism for the feedback scheduler is also developed. Simulation results show that the proposed approach is efficient in dealing with channel capacity variations and noise interference, thus providing an enabling technology for control over WLAN. PMID:27879934

  17. A Knowledge-Structure-Based Adaptive Dynamic Assessment System for Calculus Learning

    ERIC Educational Resources Information Center

    Ting, M.-Y.; Kuo, B.-C.

    2016-01-01

    The purpose of this study was to investigate the effect of a calculus system that was designed using an adaptive dynamic assessment (DA) framework on performance in the "finding an area using an integral". In this study, adaptive testing and dynamic assessment were combined to provide different test items depending on students'…

  18. Adaptive sliding mode control for a class of chaotic systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Farid, R.; Ibrahim, A.; Zalam, B., E-mail: ramy5475@yahoo.com

    2015-03-30

    Chaos control here means to design a controller that is able to mitigating or eliminating the chaos behavior of nonlinear systems that experiencing such phenomenon. In this paper, an Adaptive Sliding Mode Controller (ASMC) is presented based on Lyapunov stability theory. The well known Chua's circuit is chosen to be our case study in this paper. The study shows the effectiveness of the proposed adaptive sliding mode controller.

  19. Soft systems thinking and social learning for adaptive management.

    PubMed

    Cundill, G; Cumming, G S; Biggs, D; Fabricius, C

    2012-02-01

    The success of adaptive management in conservation has been questioned and the objective-based management paradigm on which it is based has been heavily criticized. Soft systems thinking and social-learning theory expose errors in the assumption that complex systems can be dispassionately managed by objective observers and highlight the fact that conservation is a social process in which objectives are contested and learning is context dependent. We used these insights to rethink adaptive management in a way that focuses on the social processes involved in management and decision making. Our approach to adaptive management is based on the following assumptions: action toward a common goal is an emergent property of complex social relationships; the introduction of new knowledge, alternative values, and new ways of understanding the world can become a stimulating force for learning, creativity, and change; learning is contextual and is fundamentally about practice; and defining the goal to be addressed is continuous and in principle never ends. We believe five key activities are crucial to defining the goal that is to be addressed in an adaptive-management context and to determining the objectives that are desirable and feasible to the participants: situate the problem in its social and ecological context; raise awareness about alternative views of a problem and encourage enquiry and deconstruction of frames of reference; undertake collaborative actions; and reflect on learning. ©2011 Society for Conservation Biology.

  20. Active listening room compensation for massive multichannel sound reproduction systems using wave-domain adaptive filtering.

    PubMed

    Spors, Sascha; Buchner, Herbert; Rabenstein, Rudolf; Herbordt, Wolfgang

    2007-07-01

    The acoustic theory for multichannel sound reproduction systems usually assumes free-field conditions for the listening environment. However, their performance in real-world listening environments may be impaired by reflections at the walls. This impairment can be reduced by suitable compensation measures. For systems with many channels, active compensation is an option, since the compensating waves can be created by the reproduction loudspeakers. Due to the time-varying nature of room acoustics, the compensation signals have to be determined by an adaptive system. The problems associated with the successful operation of multichannel adaptive systems are addressed in this contribution. First, a method for decoupling the adaptation problem is introduced. It is based on a generalized singular value decomposition and is called eigenspace adaptive filtering. Unfortunately, it cannot be implemented in its pure form, since the continuous adaptation of the generalized singular value decomposition matrices to the variable room acoustics is numerically very demanding. However, a combination of this mathematical technique with the physical description of wave propagation yields a realizable multichannel adaptation method with good decoupling properties. It is called wave domain adaptive filtering and is discussed here in the context of wave field synthesis.

  1. Direct adaptive control of wind energy conversion systems using Gaussian networks.

    PubMed

    Mayosky, M A; Cancelo, I E

    1999-01-01

    Grid connected wind energy conversion systems (WECS) present interesting control demands, due to the intrinsic nonlinear characteristics of windmills and electric generators. In this paper a direct adaptive control strategy for WECS control is proposed. It is based on the combination of two control actions: a radial basis zfunction network-based adaptive controller, which drives the tracking error to zero with user specified dynamics, and a supervisory controller, based on crude bounds of the system's nonlinearities. The supervisory controller fires when the finite neural-network approximation properties cannot be guaranteed. The form of the supervisor control and the adaptation law for the neural controller are derived from a Lyapunov analysis of stability. The results are applied to a typical turbine/generator pair, showing the feasibility of the proposed solution.

  2. Embedded intelligent adaptive PI controller for an electromechanical system.

    PubMed

    El-Nagar, Ahmad M

    2016-09-01

    In this study, an intelligent adaptive controller approach using the interval type-2 fuzzy neural network (IT2FNN) is presented. The proposed controller consists of a lower level proportional - integral (PI) controller, which is the main controller and an upper level IT2FNN which tuning on-line the parameters of a PI controller. The proposed adaptive PI controller based on IT2FNN (API-IT2FNN) is implemented practically using the Arduino DUE kit for controlling the speed of a nonlinear DC motor-generator system. The parameters of the IT2FNN are tuned on-line using back-propagation algorithm. The Lyapunov theorem is used to derive the stability and convergence of the IT2FNN. The obtained experimental results, which are compared with other controllers, demonstrate that the proposed API-IT2FNN is able to improve the system response over a wide range of system uncertainties. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

  3. Copyright for Interactive Systems: Stratagems for Tourism and Cultural Heritage Promotion

    NASA Astrophysics Data System (ADS)

    Cipolla-Ficarra, Francisco V.; Cipolla-Ficarra, Miguel; Ficarra, Valeria M.

    We present a series of strategies followed from the interactive design for the realization of a hypermedia system aimed at promoting in an original, simple and universal way the cultural and tourism heritage of a wide rural area in two Italian regions: Emilia Romagna and Lombardy. Besides, the main stratagems followed are disclosed to overcome the existing hurdles when it comes to copyright for the free diffusion of the tourism view of the area, such as can be photography or video, for instance. Finally, we present the first vademecum to be considered before making on-line and off-line interactive systems in Italy.

  4. Fuzzy Adaptive Cubature Kalman Filter for Integrated Navigation Systems.

    PubMed

    Tseng, Chien-Hao; Lin, Sheng-Fuu; Jwo, Dah-Jing

    2016-07-26

    This paper presents a sensor fusion method based on the combination of cubature Kalman filter (CKF) and fuzzy logic adaptive system (FLAS) for the integrated navigation systems, such as the GPS/INS (Global Positioning System/inertial navigation system) integration. The third-degree spherical-radial cubature rule applied in the CKF has been employed to avoid the numerically instability in the system model. In processing navigation integration, the performance of nonlinear filter based estimation of the position and velocity states may severely degrade caused by modeling errors due to dynamics uncertainties of the vehicle. In order to resolve the shortcoming for selecting the process noise covariance through personal experience or numerical simulation, a scheme called the fuzzy adaptive cubature Kalman filter (FACKF) is presented by introducing the FLAS to adjust the weighting factor of the process noise covariance matrix. The FLAS is incorporated into the CKF framework as a mechanism for timely implementing the tuning of process noise covariance matrix based on the information of degree of divergence (DOD) parameter. The proposed FACKF algorithm shows promising accuracy improvement as compared to the extended Kalman filter (EKF), unscented Kalman filter (UKF), and CKF approaches.

  5. Fuzzy Adaptive Cubature Kalman Filter for Integrated Navigation Systems

    PubMed Central

    Tseng, Chien-Hao; Lin, Sheng-Fuu; Jwo, Dah-Jing

    2016-01-01

    This paper presents a sensor fusion method based on the combination of cubature Kalman filter (CKF) and fuzzy logic adaptive system (FLAS) for the integrated navigation systems, such as the GPS/INS (Global Positioning System/inertial navigation system) integration. The third-degree spherical-radial cubature rule applied in the CKF has been employed to avoid the numerically instability in the system model. In processing navigation integration, the performance of nonlinear filter based estimation of the position and velocity states may severely degrade caused by modeling errors due to dynamics uncertainties of the vehicle. In order to resolve the shortcoming for selecting the process noise covariance through personal experience or numerical simulation, a scheme called the fuzzy adaptive cubature Kalman filter (FACKF) is presented by introducing the FLAS to adjust the weighting factor of the process noise covariance matrix. The FLAS is incorporated into the CKF framework as a mechanism for timely implementing the tuning of process noise covariance matrix based on the information of degree of divergence (DOD) parameter. The proposed FACKF algorithm shows promising accuracy improvement as compared to the extended Kalman filter (EKF), unscented Kalman filter (UKF), and CKF approaches. PMID:27472336

  6. Method and system for environmentally adaptive fault tolerant computing

    NASA Technical Reports Server (NTRS)

    Copenhaver, Jason L. (Inventor); Jeremy, Ramos (Inventor); Wolfe, Jeffrey M. (Inventor); Brenner, Dean (Inventor)

    2010-01-01

    A method and system for adapting fault tolerant computing. The method includes the steps of measuring an environmental condition representative of an environment. An on-board processing system's sensitivity to the measured environmental condition is measured. It is determined whether to reconfigure a fault tolerance of the on-board processing system based in part on the measured environmental condition. The fault tolerance of the on-board processing system may be reconfigured based in part on the measured environmental condition.

  7. Swarm Intelligence: New Techniques for Adaptive Systems to Provide Learning Support

    ERIC Educational Resources Information Center

    Wong, Lung-Hsiang; Looi, Chee-Kit

    2012-01-01

    The notion of a system adapting itself to provide support for learning has always been an important issue of research for technology-enabled learning. One approach to provide adaptivity is to use social navigation approaches and techniques which involve analysing data of what was previously selected by a cluster of users or what worked for…

  8. A low cost, adaptive mixed reality system for home-based stroke rehabilitation.

    PubMed

    Chen, Yinpeng; Baran, Michael; Sundaram, Hari; Rikakis, Thanassis

    2011-01-01

    This paper presents a novel, low-cost, real-time adaptive multimedia environment for home-based upper extremity rehabilitation of stroke survivors. The primary goal of this system is to provide an interactive tool with which the stroke survivor can sustain gains achieved within the clinical phase of therapy and increase the opportunity for functional recovery. This home-based mediated system has low cost sensing, off the shelf components for the auditory and visual feedback, and remote monitoring capability. The system is designed to continue active learning by reducing dependency on real-time feedback and focusing on summary feedback after a single task and sequences of tasks. To increase system effectiveness through customization, we use data from the training strategy developed by the therapist at the clinic for each stroke survivor to drive automated system adaptation at the home. The adaptation includes changing training focus, selecting proper feedback coupling both in real-time and in summary, and constructing appropriate dialogues with the stroke survivor to promote more efficient use of the system. This system also allows the therapist to review participant's progress and adjust the training strategy weekly.

  9. Output Feedback Adaptive Control of Non-Minimum Phase Systems Using Optimal Control Modification

    NASA Technical Reports Server (NTRS)

    Nguyen, Nhan; Hashemi, Kelley E.; Yucelen, Tansel; Arabi, Ehsan

    2018-01-01

    This paper describes output feedback adaptive control approaches for non-minimum phase SISO systems with relative degree 1 and non-strictly positive real (SPR) MIMO systems with uniform relative degree 1 using the optimal control modification method. It is well-known that the standard model-reference adaptive control (MRAC) cannot be used to control non-SPR plants to track an ideal SPR reference model. Due to the ideal property of asymptotic tracking, MRAC attempts an unstable pole-zero cancellation which results in unbounded signals for non-minimum phase SISO systems. The optimal control modification can be used to prevent the unstable pole-zero cancellation which results in a stable adaptation of non-minimum phase SISO systems. However, the tracking performance using this approach could suffer if the unstable zero is located far away from the imaginary axis. The tracking performance can be recovered by using an observer-based output feedback adaptive control approach which uses a Luenberger observer design to estimate the state information of the plant. Instead of explicitly specifying an ideal SPR reference model, the reference model is established from the linear quadratic optimal control to account for the non-minimum phase behavior of the plant. With this non-minimum phase reference model, the observer-based output feedback adaptive control can maintain stability as well as tracking performance. However, in the presence of the mismatch between the SPR reference model and the non-minimum phase plant, the standard MRAC results in unbounded signals, whereas a stable adaptation can be achieved with the optimal control modification. An application of output feedback adaptive control for a flexible wing aircraft illustrates the approaches.

  10. Corresponding color datasets and a chromatic adaptation model based on the OSA-UCS system.

    PubMed

    Oleari, Claudio

    2014-07-01

    Today chromatic adaptation transforms (CATs) are reconsidered, since their mathematical inconsistency has been shown in Color Res. Appl.38, 188 (2013) and by the CIE technical committee TC 8-11: CIECAM02 Mathematics. In 2004-2005 the author proposed an adaptation transform based on the uniform color scale system of the Optical Society of America (OSA-UCS) [J. Opt. Soc. Am. A21, 677 (2004); Color Res. Appl. 30, 31 (2005)] that transforms the cone-activation stimuli into adapted stimuli. The present work considers all the 37 available corresponding color (CC) datasets selected by CIE and (1) shows that the adapted stimuli obtained from CC data are defined up to an unknown transformation, and an unambiguous definition of the adapted stimuli requires additional hypotheses or suitable experimental data (as it is in the OSA-UCS system); (2) produces a CAT, represented by a linear transformation between CCs, associated with any CC dataset, whose high quality measured in ΔE units discards the possibility of nonlinear transformations; (3) analyzes these color-conversion matrices in a heuristic way with a reference adaptation that is approximately that of the OSA-UCS adapted colors for the D65 illuminant and particularly shows accordance with the Hunt effect and the Bezold-Brücke hue shift; (4) proposes the measurements of CC stimuli with a reference adaptation equal to that of the visual situation of the OSA-UCS system for defining adapted colors for any considered illumination adaptation and therefore for defining a general CAT formula.

  11. Adaptive automation of human-machine system information-processing functions.

    PubMed

    Kaber, David B; Wright, Melanie C; Prinzel, Lawrence J; Clamann, Michael P

    2005-01-01

    The goal of this research was to describe the ability of human operators to interact with adaptive automation (AA) applied to various stages of complex systems information processing, defined in a model of human-automation interaction. Forty participants operated a simulation of an air traffic control task. Automated assistance was adaptively applied to information acquisition, information analysis, decision making, and action implementation aspects of the task based on operator workload states, which were measured using a secondary task. The differential effects of the forms of automation were determined and compared with a manual control condition. Results of two 20-min trials of AA or manual control revealed a significant effect of the type of automation on performance, particularly during manual control periods as part of the adaptive conditions. Humans appear to better adapt to AA applied to sensory and psychomotor information-processing functions (action implementation) than to AA applied to cognitive functions (information analysis and decision making), and AA is superior to completely manual control. Potential applications of this research include the design of automation to support air traffic controller information processing.

  12. Control Systems with Normalized and Covariance Adaptation by Optimal Control Modification

    NASA Technical Reports Server (NTRS)

    Nguyen, Nhan T. (Inventor); Burken, John J. (Inventor); Hanson, Curtis E. (Inventor)

    2016-01-01

    Disclosed is a novel adaptive control method and system called optimal control modification with normalization and covariance adjustment. The invention addresses specifically to current challenges with adaptive control in these areas: 1) persistent excitation, 2) complex nonlinear input-output mapping, 3) large inputs and persistent learning, and 4) the lack of stability analysis tools for certification. The invention has been subject to many simulations and flight testing. The results substantiate the effectiveness of the invention and demonstrate the technical feasibility for use in modern aircraft flight control systems.

  13. Feasibility Analysis and Evaluation of an Adaptive Tracked Vehicle Suspension and Control System

    DTIC Science & Technology

    1975-06-01

    CONTROL SYSTEM FINAL REPORT JUNE 1975 Contract No. DAAE07-72-C-017 D D C •W 6 1976 B t> y Robert M. Salemka National Water Lift Company A...spring rate which is as soft as a hydropneumatic system. 3.3 Adaptive Control The adaptive control was achieved by switching the jounce damping relief...inherently included in this type of system. The solenoid valves are of the normally closed type so that with no electrical power , the system will

  14. Adaptive Fault-Tolerant Control of Uncertain Nonlinear Large-Scale Systems With Unknown Dead Zone.

    PubMed

    Chen, Mou; Tao, Gang

    2016-08-01

    In this paper, an adaptive neural fault-tolerant control scheme is proposed and analyzed for a class of uncertain nonlinear large-scale systems with unknown dead zone and external disturbances. To tackle the unknown nonlinear interaction functions in the large-scale system, the radial basis function neural network (RBFNN) is employed to approximate them. To further handle the unknown approximation errors and the effects of the unknown dead zone and external disturbances, integrated as the compounded disturbances, the corresponding disturbance observers are developed for their estimations. Based on the outputs of the RBFNN and the disturbance observer, the adaptive neural fault-tolerant control scheme is designed for uncertain nonlinear large-scale systems by using a decentralized backstepping technique. The closed-loop stability of the adaptive control system is rigorously proved via Lyapunov analysis and the satisfactory tracking performance is achieved under the integrated effects of unknown dead zone, actuator fault, and unknown external disturbances. Simulation results of a mass-spring-damper system are given to illustrate the effectiveness of the proposed adaptive neural fault-tolerant control scheme for uncertain nonlinear large-scale systems.

  15. Implementation of an Adaptive Controller System from Concept to Flight Test

    NASA Technical Reports Server (NTRS)

    Larson, Richard R.; Burken, John J.; Butler, Bradley S.; Yokum, Steve

    2009-01-01

    The National Aeronautics and Space Administration Dryden Flight Research Center (Edwards, California) is conducting ongoing flight research using adaptive controller algorithms. A highly modified McDonnell-Douglas NF-15B airplane called the F-15 Intelligent Flight Control System (IFCS) is used to test and develop these algorithms. Modifications to this airplane include adding canards and changing the flight control systems to interface a single-string research controller processor for neural network algorithms. Research goals include demonstration of revolutionary control approaches that can efficiently optimize aircraft performance in both normal and failure conditions and advancement of neural-network-based flight control technology for new aerospace system designs. This report presents an overview of the processes utilized to develop adaptive controller algorithms during a flight-test program, including a description of initial adaptive controller concepts and a discussion of modeling formulation and performance testing. Design finalization led to integration with the system interfaces, verification of the software, validation of the hardware to the requirements, design of failure detection, development of safety limiters to minimize the effect of erroneous neural network commands, and creation of flight test control room displays to maximize human situational awareness; these are also discussed.

  16. On complex adaptive systems and terrorism [rapid communication

    NASA Astrophysics Data System (ADS)

    Ahmed, E.; Elgazzar, A. S.; Hegazi, A. S.

    2005-03-01

    Complex adaptive systems (CAS) are ubiquitous in nature. They are basic in social sciences. An overview of CAS is given with emphasize on the occurrence of bad side effects to seemingly “wise” decisions. Hence application to terrorism is given. Some conclusions on how to deal with this phenomena are proposed.

  17. Methodology: Adapting the 'Training and Visit' System to Population Programmes.

    ERIC Educational Resources Information Center

    Asian-Pacific Population Programme News, 1985

    1985-01-01

    Provides suggestions for adapting the "training and visit" (T&V) system to population programs. Summarizes six main elements of a T&V system for population, health, and nutrition programs and describes four principles of agricultural extension programs. Implications of this process are also reviewed. (ML)

  18. Nonlinear adaptive control system design with asymptotically stable parameter estimation error

    NASA Astrophysics Data System (ADS)

    Mishkov, Rumen; Darmonski, Stanislav

    2018-01-01

    The paper presents a new general method for nonlinear adaptive system design with asymptotic stability of the parameter estimation error. The advantages of the approach include asymptotic unknown parameter estimation without persistent excitation and capability to directly control the estimates transient response time. The method proposed modifies the basic parameter estimation dynamics designed via a known nonlinear adaptive control approach. The modification is based on the generalised prediction error, a priori constraints with a hierarchical parameter projection algorithm, and the stable data accumulation concepts. The data accumulation principle is the main tool for achieving asymptotic unknown parameter estimation. It relies on the parametric identifiability system property introduced. Necessary and sufficient conditions for exponential stability of the data accumulation dynamics are derived. The approach is applied in a nonlinear adaptive speed tracking vector control of a three-phase induction motor.

  19. Observed-Based Adaptive Fuzzy Tracking Control for Switched Nonlinear Systems With Dead-Zone.

    PubMed

    Tong, Shaocheng; Sui, Shuai; Li, Yongming

    2015-12-01

    In this paper, the problem of adaptive fuzzy output-feedback control is investigated for a class of uncertain switched nonlinear systems in strict-feedback form. The considered switched systems contain unknown nonlinearities, dead-zone, and immeasurable states. Fuzzy logic systems are utilized to approximate the unknown nonlinear functions, a switched fuzzy state observer is designed and thus the immeasurable states are obtained by it. By applying the adaptive backstepping design principle and the average dwell time method, an adaptive fuzzy output-feedback tracking control approach is developed. It is proved that the proposed control approach can guarantee that all the variables in the closed-loop system are bounded under a class of switching signals with average dwell time, and also that the system output can track a given reference signal as closely as possible. The simulation results are given to check the effectiveness of the proposed approach.

  20. EXSPRT: An Expert Systems Approach to Computer-Based Adaptive Testing.

    ERIC Educational Resources Information Center

    Frick, Theodore W.; And Others

    Expert systems can be used to aid decision making. A computerized adaptive test (CAT) is one kind of expert system, although it is not commonly recognized as such. A new approach, termed EXSPRT, was devised that combines expert systems reasoning and sequential probability ratio test stopping rules. EXSPRT-R uses random selection of test items,…

  1. Progress with the lick adaptive optics system

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gavel, D T; Olivier, S S; Bauman, B

    2000-03-01

    Progress and results of observations with the Lick Observatory Laser Guide Star Adaptive Optics System are presented. This system is optimized for diffraction-limited imaging in the near infrared, 1-2 micron wavelength bands. We describe our development efforts in a number of component areas including, a redesign of the optical bench layout, the commissioning of a new infrared science camera, and improvements to the software and user interface. There is also an ongoing effort to characterize the system performance with both natural and laser guide stars and to fold this data into a refined system model. Such a model can bemore » used to help plan future observations, for example, predicting the point-spread function as a function of seeing and guide star magnitude.« less

  2. Robust Wave-front Correction in a Small Scale Adaptive Optics System Using a Membrane Deformable Mirror

    NASA Astrophysics Data System (ADS)

    Choi, Y.; Park, S.; Baik, S.; Jung, J.; Lee, S.; Yoo, J.

    A small scale laboratory adaptive optics system using a Shack-Hartmann wave-front sensor (WFS) and a membrane deformable mirror (DM) has been built for robust image acquisition. In this study, an adaptive limited control technique is adopted to maintain the long-term correction stability of an adaptive optics system. To prevent the waste of dynamic correction range for correcting small residual wave-front distortions which are inefficient to correct, the built system tries to limit wave-front correction when a similar small difference wave-front pattern is repeatedly generated. Also, the effect of mechanical distortion in an adaptive optics system is studied and a pre-recognition method for the distortion is devised to prevent low-performance system operation. A confirmation process for a balanced work assignment among deformable mirror (DM) actuators is adopted for the pre-recognition. The corrected experimental results obtained by using a built small scale adaptive optics system are described in this paper.

  3. Low Temperature Shape Memory Alloys for Adaptive, Autonomous Systems Project

    NASA Technical Reports Server (NTRS)

    Falker, John; Zeitlin, Nancy; Williams, Martha; Benafan, Othmane; Fesmire, James

    2015-01-01

    The objective of this joint activity between Kennedy Space Center (KSC) and Glenn Research Center (GRC) is to develop and evaluate the applicability of 2-way SMAs in proof-of-concept, low-temperature adaptive autonomous systems. As part of this low technology readiness (TRL) activity, we will develop and train low-temperature novel, 2-way shape memory alloys (SMAs) with actuation temperatures ranging from 0 C to 150 C. These experimental alloys will also be preliminary tested to evaluate their performance parameters and transformation (actuation) temperatures in low- temperature or cryogenic adaptive proof-of-concept systems. The challenge will be in the development, design, and training of the alloys for 2-way actuation at those temperatures.

  4. Policy Tree Optimization for Adaptive Management of Water Resources Systems

    NASA Astrophysics Data System (ADS)

    Herman, J. D.; Giuliani, M.

    2016-12-01

    Water resources systems must cope with irreducible uncertainty in supply and demand, requiring policy alternatives capable of adapting to a range of possible future scenarios. Recent studies have developed adaptive policies based on "signposts" or "tipping points", which are threshold values of indicator variables that signal a change in policy. However, there remains a need for a general method to optimize the choice of indicators and their threshold values in a way that is easily interpretable for decision makers. Here we propose a conceptual framework and computational algorithm to design adaptive policies as a tree structure (i.e., a hierarchical set of logical rules) using a simulation-optimization approach based on genetic programming. We demonstrate the approach using Folsom Reservoir, California as a case study, in which operating policies must balance the risk of both floods and droughts. Given a set of feature variables, such as reservoir level, inflow observations and forecasts, and time of year, the resulting policy defines the conditions under which flood control and water supply hedging operations should be triggered. Importantly, the tree-based rule sets are easy to interpret for decision making, and can be compared to historical operating policies to understand the adaptations needed under possible climate change scenarios. Several remaining challenges are discussed, including the empirical convergence properties of the method, and extensions to irreversible decisions such as infrastructure. Policy tree optimization, and corresponding open-source software, provide a generalizable, interpretable approach to designing adaptive policies under uncertainty for water resources systems.

  5. Classrooms as Complex Adaptive Systems: A Relational Model

    ERIC Educational Resources Information Center

    Burns, Anne; Knox, John S.

    2011-01-01

    In this article, we describe and model the language classroom as a complex adaptive system (see Logan & Schumann, 2005). We argue that linear, categorical descriptions of classroom processes and interactions do not sufficiently explain the complex nature of classrooms, and cannot account for how classroom change occurs (or does not occur), over…

  6. Complex Adaptive Systems as Metaphors for Organizational Management

    ERIC Educational Resources Information Center

    Palmberg, Klara

    2009-01-01

    Purpose: The purpose of this paper is to explore the concept of complex adaptive systems (CAS) from the perspective of managing organizations, to describe and explore the management principles in a case study of an organization with unconventional ways of management and to present a tentative model for managing organizations as CAS--system…

  7. National launch strategy vehicle data management system

    NASA Technical Reports Server (NTRS)

    Cordes, David

    1990-01-01

    The national launch strategy vehicle data management system (NLS/VDMS) was developed as part of the 1990 NASA Summer Faculty Fellowship Program. The system was developed under the guidance of the Engineering Systems Branch of the Information Systems Office, and is intended for use within the Program Development Branch PD34. The NLS/VDMS is an on-line database system that permits the tracking of various launch vehicle configurations within the program development office. The system is designed to permit the definition of new launch vehicles, as well as the ability to display and edit existing launch vehicles. Vehicles can be grouped in logical architectures within the system. Reports generated from this package include vehicle data sheets, architecture data sheets, and vehicle flight rate reports. The topics covered include: (1) system overview; (2) initial system development; (3) supercard hypermedia authoring system; (4) the ORACLE database; and (5) system evaluation.

  8. Fuzzy Adaptive Control Design and Discretization for a Class of Nonlinear Uncertain Systems.

    PubMed

    Zhao, Xudong; Shi, Peng; Zheng, Xiaolong

    2016-06-01

    In this paper, tracking control problems are investigated for a class of uncertain nonlinear systems in lower triangular form. First, a state-feedback controller is designed by using adaptive backstepping technique and the universal approximation ability of fuzzy logic systems. During the design procedure, a developed method with less computation is proposed by constructing one maximum adaptive parameter. Furthermore, adaptive controllers with nonsymmetric dead-zone are also designed for the systems. Then, a sampled-data control scheme is presented to discretize the obtained continuous-time controller by using the forward Euler method. It is shown that both proposed continuous and discrete controllers can ensure that the system output tracks the target signal with a small bounded error and the other closed-loop signals remain bounded. Two simulation examples are presented to verify the effectiveness and applicability of the proposed new design techniques.

  9. ADAPT

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Reynolds, John; Jankovsky, Zachary; Metzroth, Kyle G

    2018-04-04

    The purpose of the ADAPT code is to generate Dynamic Event Trees (DET) using a user specified set of simulators. ADAPT can utilize any simulation tool which meets a minimal set of requirements. ADAPT is based on the concept of DET which uses explicit modeling of the deterministic dynamic processes that take place during a nuclear reactor plant system (or other complex system) evolution along with stochastic modeling. When DET are used to model various aspects of Probabilistic Risk Assessment (PRA), all accident progression scenarios starting from an initiating event are considered simultaneously. The DET branching occurs at user specifiedmore » times and/or when an action is required by the system and/or the operator. These outcomes then decide how the dynamic system variables will evolve in time for each DET branch. Since two different outcomes at a DET branching may lead to completely different paths for system evolution, the next branching for these paths may occur not only at separate times, but can be based on different branching criteria. The computational infrastructure allows for flexibility in ADAPT to link with different system simulation codes, parallel processing of the scenarios under consideration, on-line scenario management (initiation as well as termination), analysis of results, and user friendly graphical capabilities. The ADAPT system is designed for a distributed computing environment; the scheduler can track multiple concurrent branches simultaneously. The scheduler is modularized so that the DET branching strategy can be modified (e.g. biasing towards the worst-case scenario/event). Independent database systems store data from the simulation tasks and the DET structure so that the event tree can be constructed and analyzed later. ADAPT is provided with a user-friendly client which can easily sort through and display the results of an experiment, precluding the need for the user to manually inspect individual simulator runs.« less

  10. A synthesis theory for the externally excited adaptive system /EEAS/

    NASA Technical Reports Server (NTRS)

    Horowitz, I. M.; Smay, J. W.; Shapiro, A.

    1974-01-01

    The externally excited adaptive system (EEAS) is a two-degree-of-freedom feedback system with a nonlinearity which is saturated hard by an external periodic signal. Under certain conditions, the EEAS responds quasi-linearly to command and plant disturbance signals, permitting the development of a quantitative synthesis theory for satisfying system tolerances despite large plant uncertainty. The great advantage of the EEAS is its zero sensitivity to plant gain variations, a property it shares with the self-oscillating adaptive system (SOAS). The EEAS is, however, more flexible than the SOAS in satisfying the quasi-linearity constraints. The essential difference is that in the EEAS the loop transmission bandwidth is not rigorously tied to the 'carrier' signal, as it is in the SOAS. There is a class of problems for which the EEAS is superior to the purely linear system, which in turn is superior to the SOAS. The superiority of the EEAS over the SOAS is especially marked in the case of significant plant disturbances, which generally vitiate a SOAS design.

  11. Chronic grouped social restriction triggers long-lasting immune system adaptations.

    PubMed

    Tian, Rui; Hou, Gonglin; Song, Liuwei; Zhang, Jianming; Yuan, Ti-Fei

    2017-05-16

    Chronic stress triggers rigorous psychological and physiological changes, including immunological system adaptations. However, the effects of long-term social restriction on human immune system have not been investigated. The present study is to investigate the effect of chronic stress on immune changes in human blood, with the stress stimuli controlled.10 male volunteers were group isolated from the modern society in a 50-meter-square room for 150 days, with enriched nutrition and good living conditions provided. Serum examination of immune system markers demonstrated numerous changes in different aspects of the immune functions. The changes were observed as early as 30 days and could last for another 150 days after the termination of the restriction period (300 days' time point). The results strongly argued for the adaptation of immunological system under chronic social restriction stress in adult human, preceding a clear change in psychological conditions. The changes of these immune system factors could as well act as the serum biomarkers in clinical early-diagnosis of stress-related disorders.

  12. Adaptive gamma correction-based expert system for nonuniform illumination face enhancement

    NASA Astrophysics Data System (ADS)

    Abdelhamid, Iratni; Mustapha, Aouache; Adel, Oulefki

    2018-03-01

    The image quality of a face recognition system suffers under severe lighting conditions. Thus, this study aims to develop an approach for nonuniform illumination adjustment based on an adaptive gamma correction (AdaptGC) filter that can solve the aforementioned issue. An approach for adaptive gain factor prediction was developed via neural network model-based cross-validation (NN-CV). To achieve this objective, a gamma correction function and its effects on the face image quality with different gain values were examined first. Second, an orientation histogram (OH) algorithm was assessed as a face's feature descriptor. Subsequently, a density histogram module was developed for face label generation. During the NN-CV construction, the model was assessed to recognize the OH descriptor and predict the face label. The performance of the NN-CV model was evaluated by examining the statistical measures of root mean square error and coefficient of efficiency. Third, to evaluate the AdaptGC enhancement approach, an image quality metric was adopted using enhancement by entropy, contrast per pixel, second-derivative-like measure of enhancement, and sharpness, then supported by visual inspection. The experiment results were examined using five face's databases, namely, extended Yale-B, Carnegie Mellon University-Pose, Illumination, and Expression, Mobio, FERET, and Oulu-CASIA-NIR-VIS. The final results prove that AdaptGC filter implementation compared with state-of-the-art methods is the best choice in terms of contrast and nonuniform illumination adjustment. In summary, the benefits attained prove that AdaptGC is driven by a profitable enhancement rate, which provides satisfying features for high rate face recognition systems.

  13. Water System Adaptation To Hydrological Changes: Module 9, Water System Resilience and Security under Hydrologic Variability and Uncertainty

    EPA Science Inventory

    This course will introduce students to the fundamental principles of water system adaptation to hydrological changes, with emphasis on data analysis and interpretation, technical planning, and computational modeling. Starting with real-world scenarios and adaptation needs, the co...

  14. Flexible and adaptive water systems operations through more informed and dynamic decisions

    NASA Astrophysics Data System (ADS)

    Castelletti, A.; Giuliani, M.

    2016-12-01

    Timely adapting the operations of water systems to be resilient against rapid changes in both hydroclimatic and socioeconomic forcing is generally recommended as a part of planning and managing water resources under uncertain futures. A great opportunity to make the operations more flexible and adaptive is offered by the unprecedented amount of information that is becoming available to water system operators, providing a wide range of data at increasingly higher temporal and spatial resolution. Yet, many water systems are still operated using very simple information systems, typically based on basic statistical analysis and the operator's experience. In this work, we discuss the potential offered by incorporating improved information to enhance water systems operation and increase their ability of adapting to different external conditions and resolving potential conflicts across sectors. In particular, we focus on the use of different variables associated to different dynamics of the system (slow and fast) diversely impacting the operating objectives on the short-, medium- and long-term. The multi-purpose operations of the Hoa Binh reservoir in the Red River Basin (Vietnam) is used to demonstrate our approach. Numerical results show that our procedure is able to automatically select the most valuable information for improving the Hoa Binh operations and mitigating the conflict between short-term objectives, i.e. hydropower production and flood control. Moreover, we also successfully identify low-frequency climate information associated to El-Nino Southern Oscillation for improving the performance in terms of long-term objectives, i.e. water supply. Finally, we assess the value of better informing operational decisions for adapting the system operations to changing conditions by considering different climate change projections.

  15. An Adaptive Pheromone Updation of the Ant-System using LMS Technique

    NASA Astrophysics Data System (ADS)

    Paul, Abhishek; Mukhopadhyay, Sumitra

    2010-10-01

    We propose a modified model of pheromone updation for Ant-System, entitled as Adaptive Ant System (AAS), using the properties of basic Adaptive Filters. Here, we have exploited the properties of Least Mean Square (LMS) algorithm for the pheromone updation to find out the best minimum tour for the Travelling Salesman Problem (TSP). TSP library has been used for the selection of benchmark problem and the proposed AAS determines the minimum tour length for the problems containing large number of cities. Our algorithm shows effective results and gives least tour length in most of the cases as compared to other existing approaches.

  16. ITMS: Individualized Teaching Material System: Adaptive Integration of Web Pages Distributed in Some Servers.

    ERIC Educational Resources Information Center

    Mitsuhara, Hiroyuki; Kurose, Yoshinobu; Ochi, Youji; Yano, Yoneo

    The authors developed a Web-based Adaptive Educational System (Web-based AES) named ITMS (Individualized Teaching Material System). ITMS adaptively integrates knowledge on the distributed Web pages and generates individualized teaching material that has various contents. ITMS also presumes the learners' knowledge levels from the states of their…

  17. NASA End-to-End Data System /NEEDS/ information adaptive system - Performing image processing onboard the spacecraft

    NASA Technical Reports Server (NTRS)

    Kelly, W. L.; Howle, W. M.; Meredith, B. D.

    1980-01-01

    The Information Adaptive System (IAS) is an element of the NASA End-to-End Data System (NEEDS) Phase II and is focused toward onbaord image processing. Since the IAS is a data preprocessing system which is closely coupled to the sensor system, it serves as a first step in providing a 'Smart' imaging sensor. Some of the functions planned for the IAS include sensor response nonuniformity correction, geometric correction, data set selection, data formatting, packetization, and adaptive system control. The inclusion of these sensor data preprocessing functions onboard the spacecraft will significantly improve the extraction of information from the sensor data in a timely and cost effective manner and provide the opportunity to design sensor systems which can be reconfigured in near real time for optimum performance. The purpose of this paper is to present the preliminary design of the IAS and the plans for its development.

  18. Fast digital zooming system using directionally adaptive image interpolation and restoration.

    PubMed

    Kang, Wonseok; Jeon, Jaehwan; Yu, Soohwan; Paik, Joonki

    2014-01-01

    This paper presents a fast digital zooming system for mobile consumer cameras using directionally adaptive image interpolation and restoration methods. The proposed interpolation algorithm performs edge refinement along the initially estimated edge orientation using directionally steerable filters. Either the directionally weighted linear or adaptive cubic-spline interpolation filter is then selectively used according to the refined edge orientation for removing jagged artifacts in the slanted edge region. A novel image restoration algorithm is also presented for removing blurring artifacts caused by the linear or cubic-spline interpolation using the directionally adaptive truncated constrained least squares (TCLS) filter. Both proposed steerable filter-based interpolation and the TCLS-based restoration filters have a finite impulse response (FIR) structure for real time processing in an image signal processing (ISP) chain. Experimental results show that the proposed digital zooming system provides high-quality magnified images with FIR filter-based fast computational structure.

  19. Understanding global health governance as a complex adaptive system.

    PubMed

    Hill, Peter S

    2011-01-01

    The transition from international to global health reflects the rapid growth in the numbers and nature of stakeholders in health, as well as the constant change embodied in the process of globalisation itself. This paper argues that global health governance shares the characteristics of complex adaptive systems, with its multiple and diverse players, and their polyvalent and constantly evolving relationships, and rich and dynamic interactions. The sheer quantum of initiatives, the multiple networks through which stakeholders (re)configure their influence, the range of contexts in which development for health is played out - all compound the complexity of this system. This paper maps out the characteristics of complex adaptive systems as they apply to global health governance, linking them to developments in the past two decades, and the multiple responses to these changes. Examining global health governance through the frame of complexity theory offers insight into the current dynamics of governance, and while providing a framework for making meaning of the whole, opens up ways of accessing this complexity through local points of engagement.

  20. An Adaptive Supervisory Sliding Fuzzy Cerebellar Model Articulation Controller for Sensorless Vector-Controlled Induction Motor Drive Systems

    PubMed Central

    Wang, Shun-Yuan; Tseng, Chwan-Lu; Lin, Shou-Chuang; Chiu, Chun-Jung; Chou, Jen-Hsiang

    2015-01-01

    This paper presents the implementation of an adaptive supervisory sliding fuzzy cerebellar model articulation controller (FCMAC) in the speed sensorless vector control of an induction motor (IM) drive system. The proposed adaptive supervisory sliding FCMAC comprised a supervisory controller, integral sliding surface, and an adaptive FCMAC. The integral sliding surface was employed to eliminate steady-state errors and enhance the responsiveness of the system. The adaptive FCMAC incorporated an FCMAC with a compensating controller to perform a desired control action. The proposed controller was derived using the Lyapunov approach, which guarantees learning-error convergence. The implementation of three intelligent control schemes—the adaptive supervisory sliding FCMAC, adaptive sliding FCMAC, and adaptive sliding CMAC—were experimentally investigated under various conditions in a realistic sensorless vector-controlled IM drive system. The root mean square error (RMSE) was used as a performance index to evaluate the experimental results of each control scheme. The analysis results indicated that the proposed adaptive supervisory sliding FCMAC substantially improved the system performance compared with the other control schemes. PMID:25815450