Physical hypermedia: augmenting physical material with hypermedia structures

DEFF Research Database (Denmark)

Grønbæk, Kaj; Ørbæk, Peter; Kristensen, Jannie Friis

2003-01-01

This paper introduces the notion of physical hypermedia, addressing the problem of organizing material in mixed digital and physical environments. Based on empirical studies, we propose concepts for collectional actions and meta-data actions, and present prototypes combining principles from...... augmented reality and hypermedia to support organization of mixtures of digital and physical materials. Our prototype of a physical hypermedia system is running on an augmented architect's desk and digital walls utilizing Radio Frequency Identifier (RFID) tags as well as visual tags tracked by cameras....... It allows users to tag physical materials, and have these tracked by readers (antennas) that may become pervasive in our work environments. In the physical hypermedia system, we work with three categories of RFID tags: simple object tags, collectional tags, and tooltags invoking operations such as grouping...

Generic adaptation framework for unifying adaptive web-based systems

NARCIS (Netherlands)

Knutov, E.

2012-01-01

The Generic Adaptation Framework (GAF) research project first and foremost creates a common formal framework for describing current and future adaptive hypermedia (AHS) and adaptive webbased systems in general. It provides a commonly agreed upon taxonomy and a reference model that encompasses the

Overview of hypertext and hypermedia systems and tools appropriate for structural and materials engineering

International Nuclear Information System (INIS)

Arents, H.C.; Bogaerts, W.F.L.

1991-01-01

After a concise description of the operational characteristics and the information consultation potential of hypertext and hypermedia systems, we discuss in detail the key system characteristics one has to look at when selecting commercially available hypertext and hypermedia products which are appropriate for structural and materials engineering. We then compare a number of PC-based, Macintosh-based and workstation-based hypertext and hypermedia systems and tools, highlighting the key features of each product. Finally, we briefly point to an existing materials engineering hypermedia application and discuss how hypermedia systems might be combined with expert systems to achieve added functionality and reliability. (orig./DG)

Integrating Hypermedia Objects In An Intelligent Tutoring System

Directory of Open Access Journals (Sweden)

Emilia PECHEANU

2001-12-01

Full Text Available The paper describes the internal architecture of an Intelligent Tutoring System, CS-Tutor. The architectural design of the tutorial system was developed in a collaborative work at the Department of Computer Science of the University of Galati and the Department of Applied Informatics of the Faculty of Computer Science of Iasi. Intelligent Tutoring Systems (ITS are software packages which use the Artificial Intelligence techniques to aid in learning of some subject or skill. In recent years, Hypermedia has been gained the interest of many researchers working in the teaching field of study. The CS-Tutor internal architecture is based upon integrating Hypermedia Objects in an Intelligent Knowledge-Based frame.

Templates and Queries in Contextual Hypermedia

DEFF Research Database (Denmark)

Anderson, Kenneth Mark; Hansen, Frank Allan; Bouvin, Niels Olof

2006-01-01

discuss a framework, HyConSC, that implements this model and describe how it can be used to build new contextual hypermedia systems. Our framework aids the developer in the iterative development of contextual queries (via a dynamic query browser) and offers support for con-text matching, a key feature...... of contextual hypermedia. We have tested the framework with data and sensors taken from the HyCon contextual hypermedia system and are now migrating HyCon to this new framework....

Context-aware Mobile Hypermedia: Concepts, Framework, and Applications

DEFF Research Database (Denmark)

Hansen, Frank Allan

the requirements for context aware mobile hypermedia, both theoretically and practically, and is realized by: • A conceptual model for context-aware hypermedia, • HyCon, a framework for context-aware mobile hypermedia, • A range of hypermedia applications utilizing context-awareness to support mobile fieldwork...... moves beyond the desktop and into the physical environments we live and work in, it may be worthwhile to support these digital-physical relationships. The thesis addresses the definition, design and requirements for context-aware mobile hypermedia systems. Context-aware hypermedia applies ubiquitous...... of a framework for context-aware hypermedia, HyCon, implementing general abstractions for acquiring context information and demonstrating how traditional anchor based hypermedia models can be extended to encompass both digital and physical entities. Several prototype applications built atop HyCon are also...

Adaptive Systems in Education: A Review and Conceptual Unification

Science.gov (United States)

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…

Towards Geo-spatial Hypermedia: Concepts and Prototype Implementation

DEFF Research Database (Denmark)

Grønbæk, Kaj; Vestergaard, Peter Posselt; Ørbæk, Peter

2002-01-01

This paper combines spatial hypermedia with techniques from Geographical Information Systems and location based services. We describe the Topos 3D Spatial Hypermedia system and how it has been developed to support geo-spatial hypermedia coupling hypermedia information to model representations...... of real world buildings and landscapes. The prototype experiments are primarily aimed at supporting architects and landscape architects in their work on site. Here it is useful to be able to superimpose and add different layers of information to, e.g. a landscape depending on the task being worked on. We...... and indirect navigation. Finally, we conclude with a number of research issues which are central to the future development of geo-spatial hypermedia, including design issues in combining metaphorical and literal hypermedia space, as well as a discussion of the role of spatial parsing in a geo-spatial context....

PERSO: Towards an Adaptive e-Learning System

Science.gov (United States)

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…

Regional information guidance system based on hypermedia concept

Science.gov (United States)

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.

Xspect: bridging open hypermedia and XLink

DEFF Research Database (Denmark)

Christensen, B.G.; Hansen, F.A.; Bouvin, N.O.

2003-01-01

it to include another open hypermedia format, FOHM. The Xspect system, based on XSLT and Javascript, provides users with an interface to browse and merge linkbases. Xspect supports navigational hypermedia in the form of links inserted on the fly into Web pages, as well as guided tours presented as SVG. Xspect......This paper evaluates the XLink format in comparison with other linking formats. The comparison is based on Xspect, an implementation of XLink. Xspect handles transformation between an open hypermedia format (OHIF) and XLink, and the paper discusses this isomorphic transformation and generalises...

Adaptation and search: from Dexter and AHAM to GAF

NARCIS (Netherlands)

Knutov, E.; De Bra, P.M.E.; Pechenizkiy, M.; Chignell, M.H.; Toms, E.

2010-01-01

Adaptive Hypermedia Systems (AHS) have long been concentrating on adaptive guidance of links between domain concepts. Here we show parallels between navigation and linking in adaptive hypermedia on the one hand and information searching or querying on the other hand. We present a transition towards

New Review of Hypermedia and Multimedia (NRHM)

DEFF Research Database (Denmark)

to physical paper. Another example is mobile hypermedia on cell phones, PDAs, and TabletPCs. Here, hypermedia applications may take advantage of the context in terms of place, time, and the user's profile to deliver relevant information and to contextualize annotations and links created by the mobile user...... have an excellent collection of six papers discussing mobile hypermedia, context-aware hypermedia, physical hypermedia, augmented reality-based hypermedia, and hypermedia on digital paper. The first two papers, Hypermedia in the Ambient Wood by Mark J. Weal, Danius T. Michaelides, Mark K. Thompson......, and David C. De Roure and HyCon: A Framework for Context-Aware Mobile Hypermedia by Niels Olof Bouvin, Bent G. Christensen, Kaj Grnbk, and Frank Allan Hansen, focus on mobile and context-aware hypermedia. Both papers present novel hypermedia infrastructures for mobile hypermedia running on phones, PDAs...

The Role of Domain and System Knowledge on Text Comprehension and Information Search in Hypermedia

Science.gov (United States)

Waniek, Jacqueline; Schafer, Thomas

2009-01-01

The goal of this study was to examine the role of domain and system knowledge on learner performance in reading and information search in hypermedia. Previous studies have shown that prior knowledge is an important individual factor for effective hypermedia use. However, current research lacks a full understanding of how these two aspects of prior…

Expressing Adaptation Strategies Using Adaptation Patterns

Science.gov (United States)

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…

REST in practice Hypermedia and systems architecture

CERN Document Server

Webber, Jim; Robinson, Ian

2010-01-01

Why don't typical enterprise projects go as smoothly as projects you develop for the Web? Does the REST architectural style really present a viable alternative for building distributed systems and enterprise-class applications? In this insightful book, three SOA experts provide a down-to-earth explanation of REST and demonstrate how you can develop simple and elegant distributed hypermedia systems by applying the Web's guiding principles to common enterprise computing problems. You'll learn techniques for implementing specific Web technologies and patterns to solve the needs of a typical com

Hipatia: a hypermedia learning environment in mathematics

Directory of Open Access Journals (Sweden)

Marisol Cueli

2016-01-01

Full Text Available Literature revealed the benefits of different instruments for the development of mathematical competence, problem solving, self-regulated learning, affective-motivational aspects and intervention in students with specific difficulties in mathematics. However, no one tool combined all these variables. The aim of this study is to present and describe the design and development of a hypermedia tool, Hipatia. Hypermedia environments are, by definición, adaptive learning systems, which are usually a web-based application program that provide a personalized learning environment. This paper describes the principles on which Hipatia is based as well as a review of available technologies developed in different academic subjects. Hipatia was created to boost self-regulated learning, develop specific math skills, and promote effective problem solving. It was targeted toward fifth and sixth grade students with and without learning difficulties in mathematics. After the development of the tool, we concluded that it aligned well with the logic underlying the principles of self-regulated learning. Future research is needed to test the efficacy of Hipatia with an empirical methodology.

A component-based open hypermedia approach to integreting structure services

DEFF Research Database (Denmark)

Grønbæk, Kaj; Nürnberg, Peter J.; Bucka-Lassen, Dirk

1999-01-01

In this paper, we consider the issue of integrating different structure services within a component-based open hypermedia system. We do so by considering the task of collaborative editing, which calls for a variety of different structures traditionally supplied by different structure services. We...... discuss the nature of collaborative editing and how it can be supported by a combination of spatial and navigational hypermedia services. We then present a component-based open hypermedia system architecture and describe various methods of integrating different structure services provided within...... such an architecture. We show the advantages of integration within a component-based framework over other means of integration, highlighting some of the main advantages of the component-based approach to open hypermedia system design and implementation....

Bridging recommendation and adaptation: Generic Adaptation Framework - Twittomender compliance study

NARCIS (Netherlands)

Hannon, J.; Knutov, E.; De Bra, P.M.E.; Pechenizkiy, M.; McCarthy, K.; Smyth, B.; Pechenizkiy, M.; Knutov, E.; Yudelson, M.; Abel, F.; Houben, G.J.P.M.; Herder, E.

2012-01-01

In this paper we consider Recommender System (RS) modeling in terms of Adaptive Hypermedia Systems (AHS) and investigate AHS and RS functionality compliance in terms of common features, functionality, building blocks and composition of the system. We bring up complementary aspects of adaptation,

Solving-Problems and Hypermedia Systems

Directory of Open Access Journals (Sweden)

Ricardo LÓPEZ FERNÁNDEZ

2009-06-01

Full Text Available The solving problems like the transfer constitute two nuclei, related, essential in the cognitive investigation and in the mathematical education. No is in and of itself casual that, from the first moment, in the investigations on the application gives the computer science to the teaching the mathematics, cybernetic models were developed that simulated processes problem solving and transfer cotexts (GPS, 1969 and IDEA (Interactive Decision Envisioning Aid, Pea, BrunerCohen, Webster & Mellen, 1987. The present articulates it analyzes, that can contribute to the development in this respect the new technologies hypermedias, give applications that are good to implement processes of learning the heuristic thought and give the capacity of «transfer». From our perspective and from the experience that we have developed in this field, to carry out a function gives analysis and the theories on the problem solving, it requires that we exercise a previous of interpretation the central aspsects over the theories gives the solving problem and transfer starting from the classic theories on the prosecution of the information. In this sense, so much the theory gives the dual memory as the most recent, J. Anderson (1993 based on the mechanisms activation nodes information they allow to establish an interpretation suggester over the mental mechanism that you/they operate in the heuristic processes. On this analysis, the present articulates it develops a theoritical interpretation over the function gives the supports based on technology hypermedia advancing in the definition of a necessary theoretical body, having in it counts that on the other hand the practical experimentation is permanent concluding in the efficiency and effectiveness gives the support hypermedia like mechanism of comunication in the processes heuristic learning.

Automation and hypermedia technology applications

Science.gov (United States)

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.

Design issues for a Dexter-based hypermedia system

DEFF Research Database (Denmark)

Grønbæk, Kaj; Trigg, Randall H.

1992-01-01

This paper discusses experiences and lessons learned from the design of an openhypermedia system, one that integrates applications and data not "owned" bythe hypermedia. The Dexter Hypertext Reference Model [8] was used as thebasis for the design. Though our experiences were generally positive, we...... foundthe model constraining in certain ways and underdeveloped in others. Forinstance, Dexter argues against dangling links, but we found several situationswhere permitting and supporting...

Development and evaluation of a hypermedia system that integrates basic concepts of mechanics, biomechanics and human anatomy

Directory of Open Access Journals (Sweden)

Flavia Rezende

2006-08-01

Full Text Available This work describes the modeling of a hypermedia learning system (called “Biomec” that integrates physical, biomechanical and anatomical concepts involved in the human motion and a study carried out with undergraduate students who interacted with the system. The instructional design of the “Biomec” hypermedia system was developed on the basis of a theoretical framework which articulates the Cognitive Flexibility Theory and the interdisciplinary approach to knowledge. The system was evaluated based on its use by students of Biomechanics I and Kinesiology in a Pre Service Teachers Training Course of Physical Education aiming to discuss the following questions: (i what is its impact on the students’ attitude related to Physics? (ii in what extent does the hypertextual approach to the content favor the interdisciplinary conception of human motion? (iii in what extent do the students’ navigation profiles adapt to conceptual needs of the different disciplines of the course? The students answered instruments that assessed affective and cognitive aspects before and after the interaction with the system, and had their navigation registered and analyzed. The set of data obtained allowed to conclude that the “Biomec” system is a relevant instructional material, capable of positively influence the students’ attitude related to Physics, to favor the interdisciplinary approach of human motion and to attend the students enrolled in Biomechanics I better than the students enrolled in Kinesiology.

Physical Hypermedia: Organising Collections of Mixed Physical and Digital Material

DEFF Research Database (Denmark)

Grønbæk, Kaj; Kristensen, Jannie Friis; Ørbæk, Peter

2003-01-01

This paper introduces the notion of physical hypermedia, addressing the problem of organizing material in mixed digital and physical environments. Based on empirical studies, we propose concepts for collectional actions and meta-data actions, and present prototypes combining principles from...... augmented reality and hypermedia to support organization of mixtures of digital and physical materials. Our prototype of a physical hypermedia system is running on an augmented architect's desk and digital walls utilizing Radio Frequency Identifier (RFID) tags as well as visual tags tracked by cameras....... It allows users to tag physical materials, and have these tracked by readers (antennas) that may become pervasive in our work environments. In the physical hypermedia system, we work with three categories of RFID tags: simple object tags, collectional tags, and tooltags invoking operations such as grouping...

Defining adaptation in a generic multi layer model: CAM: The GRAPPLE Conceptual Adaptation Model

NARCIS (Netherlands)

Hendrix, M.; De Bra, P.M.E.; Pechenizkiy, M.; Smits, D.; Cristea, A.I.; Dillenbourg, P.; Specht, M.

2008-01-01

Authoring of Adaptive Hypermedia is a difficult and time consuming task. Reference models like LAOS and AHAM separate adaptation and content in different layers. Systems like AHA!, offer graphical tools based on these models to allow authors to define adaptation without knowing any adaptation

A model for hypermedia learning environments based on electronic books

Directory of Open Access Journals (Sweden)

Ignacio Aedo

1997-12-01

Full Text Available Current hypermedia learning environments do not have a common development basis. Their designers have often used ad-hoc solutions to solve the learning problems they have encountered. However, hypermedia technology can take advantage of employing a theoretical scheme - a model - which takes into account various kinds of learning activities, and solves some of the problems associated with its use in the learning process. The model can provide designers with the tools for creating a hypermedia learning system, by allowing the elements and functions involved in the definition of a specific application to be formally represented.

Open Hypermedia as User Controlled Meta Data for the Web

DEFF Research Database (Denmark)

Grønbæk, Kaj; Sloth, Lennert; Bouvin, Niels Olof

2000-01-01

This paper introduces an approach to utilise open hypermedia structures such as links, annotations, collections and guided tours as meta data for Web resources. The paper introduces an XML based data format, called Open Hypermedia Interchange Format - OHIF, for such hypermedia structures. OHIF...... distributed open hypermedia linking between Web pages and WebDAV aware desktop applications. The paper describes the OHIF format and demonstrates how the Webvise system handles OHIF. Finally, it argues for better support for handling user controlled meta data, e.g. support for linking in non-XML data...... resembles XLink with respect to its representation of out-of-line links, but it goes beyond XLink with a more rich set of structuring mechanisms, including e.g. composites. Moreover OHIF includes an addressing mechanisms (LocSpecs) that goes beyond XPointer and URL in its ability to locate non-XML data...

GALE: a generic open source extensible adaptation engine

Science.gov (United States)

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.

Augmenting the Web through Open Hypermedia

DEFF Research Database (Denmark)

Bouvin, N.O.

2003-01-01

Based on an overview of Web augmentation and detailing the three basic approaches to extend the hypermedia functionality of the Web, the author presents a general open hypermedia framework (the Arakne framework) to augment the Web. The aim is to provide users with the ability to link, annotate, a......, and otherwise structure Web pages, as they see fit. The paper further discusses the possibilities of the concept through the description of various experiments performed with an implementation of the framework, the Arakne Environment......Based on an overview of Web augmentation and detailing the three basic approaches to extend the hypermedia functionality of the Web, the author presents a general open hypermedia framework (the Arakne framework) to augment the Web. The aim is to provide users with the ability to link, annotate...

Hypermedia Genes An Evolutionary Perspective on Concepts, Models, and Architectures

CERN Document Server

Guimarães, Nuno

2009-01-01

The design space of information services evolved from seminal works through a set of prototypical hypermedia systems and matured in open and widely accessible web-based systems. The original concepts of hypermedia systems are now expressed in different forms and shapes. The first works on hypertext invented the term itself, laid out the foundational concept of association or link, and highlighted navigation as the core paradigm for the future information systems. The first engineered systems demonstrated architectural requirements and models and fostered the emergence of the conceptual model r

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

Science.gov (United States)

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…

Flexible Adaptivity in AEHS Using Policies

NARCIS (Netherlands)

Koesling, Arne; Krause, Daniel; Herder, Eelco

2008-01-01

Koesling, A., Krause, D., & Herder, E. (2008). Flexible Adaptivity in AEHS Using Policies. In W. Nejdl, J. Kay, P. Pu & E. Herder (Eds.), Proceedings Adaptive Hypermedia and Adaptive Web-Based Systems 5th International Conference, AH 2008 (pp. 410-415). July 29-August, 1, 2008, Hannover, Germany:

Automatic presentation generation for scholarly hypermedia

NARCIS (Netherlands)

S. Bocconi

2003-01-01

textabstractAutomatic hypermedia presentation generation uses an information source semantic network first to select the content and then to compose it in the presentation so that the semantic relations between the information items are conveyed to the user. A hypermedia presentation can be

Towards Computerized Adaptive Assessment Based on Structured Tasks

NARCIS (Netherlands)

Tvarožek, Jozef; Kravcik, Milos; Bieliková, Mária

2008-01-01

Tvarožek, J., Kravčík, M., & Bieliková, M. (2008). Towards Computerized Adaptive Assessment Based on Structured Tasks. In W. Nejdl et al. (Eds.), Adaptive Hypermedia and Adaptive Web-Based Systems (pp. 224-234). Springer Berlin / Heidelberg.

Domestic Hypermedia: Mixed Media in the Home

DEFF Research Database (Denmark)

Grønbæk, Kaj; Petersen, Marianne Graves

2004-01-01

, domestic materials, such as photos, music, messages. become digitized. Based on the analyses we propose a Domestic Hypermedia infrastructure combining spatial, context-aware and physical hypermedia to support collaborative structuring and ambient presentation of materials in homes.......This paper analyses the potentials for use of hypermedia in homes based on empirical studies. The use of physical materials is characterized by collaborative spatial organization and persistent visual awareness. Qualities that are currently not well supported for digital materials. However...

Hypermedia Concepts and Research: An Overview.

Science.gov (United States)

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)

Dynamic Use of Digital Library Material - Supporting Users with Typed Links in Open Hypermedia

DEFF Research Database (Denmark)

Grønbæk, Kaj; Hansen, Klaus Marius; Yndigegn, Christian

1999-01-01

This paper introduces a novel approach to supporting digital library users in organising and annotating material. We have extended the concept of open hypermedia by introducing typed links, which support: addition of (user-defined) semantics to hypertexts, user navigation, and machine supported...... analysis and synthesis of hypermedia structures. The Webvise open hypermedia system is integrated with the World Wide Web, and has been augmented with a type system. We illustrate the potential use in the context of digital libraries with a scenario of teachers jointly preparing a course based on digital...... library material....

A knowledge base browser using hypermedia

Science.gov (United States)

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.

The Effectiveness of Hypermedia Instructional Modules for Radiology Residents.

Science.gov (United States)

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…

Using Scaffolds in Problem-Based Hypermedia

Science.gov (United States)

Su, Yuyan; Klein, James D.

2010-01-01

This study investigated the use of scaffolds in problem-based hypermedia. Three hundred and twelve undergraduate students enrolled in a computer literacy course worked in project teams to use a hypermedia PBL program focused on designing a personal computer. The PBL program included content scaffolds, metacognitive scaffolds, or no scaffolds.…

New Review of Hypermedia and Multimedia (NRHM)

DEFF Research Database (Denmark)

The main theme for the 2003 issue of NRHM in Hypermedia Beyond the Desktop (Guest Editor, Kaj Grnbk). We would like to thank all the authors who submitted papers—both those that have been accepted and the numerous worthwhile contributions that could not be accepted. The reviewers deserve special...... recognition, having contributed substantially to the selection of papers and provision of feedback that helped refine and finalise the papers. This is the first issue published by Taylor & Francis. Starting with this issue. NRHM has a new look and will appear in both print and digital formats. The online NRHM....... Introduction to Hypermedia Beyond the Desktop   Hypermedia has for many years been dealing with purely electronic documents and structures being handled on traditional windows, icons, menus, and pointers (WIMP) interfaces for desktop computers. The Hypermedia and Web research communities have provided many...

The Use of Hypermedia in Implicit Vocabulary Learning

Directory of Open Access Journals (Sweden)

Patrícia Nora de Souza

2011-07-01

Full Text Available The present work is aimed at investigating the role of hypermedia in implicit vocabulary acquisition in foreign language. On theoretical grounds, the work presents a reflection which contextualizes the discussion on implicit approaches to vocabulary teaching. Besides, a review and a discussion of the literature is carried out, with regard to the advantages of hypermedia in English Language Teaching. Following that, the selection of hypermedia material for implicit vocabulary teaching is presented. This material was used in the data collecting which comprised 75 students. The material was evaluated by the students through a questionnaire. The results show that the use of hypermedia can significantly contribute to implicit vocabulary acquisition.

The Use of Hypermedia in Implicit Vocabulary Learning

OpenAIRE

Patrícia Nora de Souza

2011-01-01

The present work is aimed at investigating the role of hypermedia in implicit vocabulary acquisition in foreign language. On theoretical grounds, the work presents a reflection which contextualizes the discussion on implicit approaches to vocabulary teaching. Besides, a review and a discussion of the literature is carried out, with regard to the advantages of hypermedia in English Language Teaching. Following that, the selection of hypermedia material for implicit vocabulary teaching is prese...

Swarm-based adaptation: wayfinding support for lifelong learners

NARCIS (Netherlands)

Tattersall, Colin; Van den Berg, Bert; Van Es, René; Janssen, José; Manderveld, Jocelyn; Koper, Rob

2004-01-01

Please refer to the orinigal publication in: Tattersall, C. Van den Berg, B., Van Es, R., Janssen, J., Manderveld, J., Koper, R. (2004). Swarm-based adaptation: wayfinding support for lifelong learners. In P. de Bra & W. Nejdl, Adaptive Hypermedia and Adaptive Web-Based Systems (LNCS3137), (pp.

A visual retrieval environment for hypermedia information system

Energy Technology Data Exchange (ETDEWEB)

Lucarella, D; Zanzi, A [ENEL s.p.a., Centro Ricerca di Automatica, Cologno Monzese, Milan (Italy)

1995-03-01

The authors a graph-based object model that may be used as a uniform framework for direct manipulation of multimedia information. After an introduction motivating the need for abstraction and structuring mechanisms in hypermedia systems, the authors introduce the data model and the notion of perspective, a form of data abstraction that acts as a user interface to the system, providing control over the visibility of the objects and their properties. A perspective is defined to include an intention and an extension. The authors present a visual retrieval environment that effectively combines filtering, browsing, and navigation to provide an integrated view of the retrieval problem. Design and implementation issues are outlined for MORE (Multimedia Object Retrieval Environment), a prototype system relying on the proposed model. The focus is on the main user interface functionalities, and actual interaction sessions are presented including schema creation, information loading, and information retrieval

Cooperative use of MHEG and HyTime in Hypermedia Environments

OpenAIRE

Rutledge, Lloyd; Ossenbruggen, Jacco; Hardman, Lynda; Bulterman, Dick; Balbe, J.-P.; Lelu, A.; Nanard, M.; Saleh, I.

1997-01-01

textabstractThe standards MHEG-5 and HyTime are interchange formats for hypermedia information. While they may seem to compete, they actually play separate and complementary roles in a complete and open hypermedia environment. MHEG-5 is used for portable final-form hypermedia presentations. HyTime is used for the long-term, presentation-independent storage of hypermedia documents. Given these tasks, MHEG-5 can be used to encode presentations of HyTime documents. This paper explores these two ...

Prototypic implementations of the building block for component based open Hypermedia systems (BB/CB-OHSs)

DEFF Research Database (Denmark)

Mohamed, Omer I. Eldai

2005-01-01

In this paper we describe the prototypic implementations of the BuildingBlock (BB/CB-OHSs) that proposed to address some of the Component-based Open Hypermedia Systems (CB-OHSs) issues, including distribution and interoperability [4, 11, 12]. Four service implementations were described below. The...

Cooperative use of MHEG and HyTime in Hypermedia Environments

NARCIS (Netherlands)

L. Rutledge (Lloyd); J.R. van Ossenbruggen (Jacco); L. Hardman (Lynda); D.C.A. Bulterman (Dick); J.-P. Balbe; A. Lelu; M. Nanard; I. Saleh

1997-01-01

textabstractThe standards MHEG-5 and HyTime are interchange formats for hypermedia information. While they may seem to compete, they actually play separate and complementary roles in a complete and open hypermedia environment. MHEG-5 is used for portable final-form hypermedia presentations. HyTime

Teaching Hypertext and Hypermedia through the Web.

Science.gov (United States)

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…

Teaching hypertext and hypermedia through the web

NARCIS (Netherlands)

De Bra, P.M.E.

1996-01-01

Since early 1994 the introductory course 2L670, "Hypermedia Structures and Systems", has been available on World Wide Web, and is an optional part of the curriculum in computing science at the Eindhoven University of Technology. The course has since been completed by more than 200 students from

ALAT: Finally an Easy To Use Adaptation Authoring Tool

NARCIS (Netherlands)

De Bra, Paul; Stash, Natalia; Boereboom, Wouter; Chen, Celine; Den Ouden, Joris; Kunstman, Martijn; Oostrum, John; Verbakel, Egon

2016-01-01

Research papers about adaptive hypermedia systems, frameworks or applications tend to focus on the end-result: how the applications are used by end-users, how adaptation improves user satisfaction, learning, etc. What they do not describe is how difficult and labor-intensive the creation of the

Composites in a Dexter-Based Hypermedia Framwork

DEFF Research Database (Denmark)

Grønbæk, Kaj

1994-01-01

with links to other components as in the classical systems such as NoteCards, Intermedia, and KMS. It is also shown how the powerful generic classes can be used to implement a variety of useful hypermedia concepts such as: hierarchy by inclusion, hierarchy by reference, virtual and computed browsers, Table...

Semantic HyperMultimedia Adaptation Schemes and Applications

CERN Document Server

Bieliková, Mária; Mylonas, Phivos; Tsapatsoulis, Nicolas

2013-01-01

Nowadays, more and more users are witnessing the impact of Hypermedia/Multimedia as well as the penetration of social applications in their life. Parallel to the evolution of the Internet and Web, several Hypermedia/Multimedia schemes and technologies bring semantic-based intelligent, personalized and adaptive services to the end users. More and more techniques are applied in media systems in order to be user/group-centric, adapting to different content and context features of a single or a community user. In respect to all the above, researchers need to explore and study the plethora of challenges that emergent personalisation and adaptation technologies bring to the new era. This edited volume aims to increase the awareness of researchers in this area. All contributions provide an in-depth investigation on research and deployment issues, regarding already introduced schemes and applications in Semantic Hyper/Multimedia and Social Media Adaptation. Moreover, the authors provide survey-based articles, so as p...

Hypermedia for Training: A Software and Instructional Engineering Model.

Science.gov (United States)

Cortinovis, Renato

1992-01-01

Presents an engineering environment oriented to the development of hypermedia applications for training. Training trends are described; requirements for a computer-based training (CBT) strategy are outlined; a hypermedia course structure is examined; microinstructional events (MIEs) are explained; and technology requirements and selection are…

Open Hypermedia as User Controlled Meta Data for the Web

DEFF Research Database (Denmark)

Grønbæk, Kaj; Sloth, Lennert; Bouvin, Niels Olof

2000-01-01

segments. By means of the Webvise system, OHIF structures can be authored, imposed on Web pages, and finally linked on the Web as any ordinary Web resource. Following a link to an OHIF file automatically invokes a Webvise download of the meta data structures and the annotated Web content will be displayed...... in the browser. Moreover, the Webvise system provides support for users to create, manipulate, and share the OHIF structures together with custom made web pages and MS Office 2000 documents on WebDAV servers. These Webvise facilities goes beyond ealier open hypermedia systems in that it now allows fully...... distributed open hypermedia linking between Web pages and WebDAV aware desktop applications. The paper describes the OHIF format and demonstrates how the Webvise system handles OHIF. Finally, it argues for better support for handling user controlled meta data, e.g. support for linking in non-XML data...

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

Science.gov (United States)

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

The Gaia Framework: Version Support In Web Based Open Hypermedia

DEFF Research Database (Denmark)

Grønbæk, Kaj; Kejser, Thomas

2004-01-01

The GAIA framework prototype, described herein, explores the possibilities and problems that arise when combining versioning and open hypermedia paradigms. It will be argued that it - by adding versioning as a separate service in the hypermedia architecture – is possible to build consistent...... versioning field and GAIA is compared with previous attempts at defining hypermedia versioning frameworks. GAIA is capable of multi-level versioning and versioning of structures and supports freezing mechanisms for both documents and hyperstructure. The experiences from GAIA provide an input to new reference...

The Gaia Framework: Version Support In Web Based Open Hypermedia

DEFF Research Database (Denmark)

Kejser, Thomas; Grønbæk, Kaj

2003-01-01

The GAIA framework prototype, described herein, explores the possibilities and problems that arise when combining versioning and open hypermedia paradigms. It will be argued that it - by adding versioning as a separate service in the hypermedia architecture - is possible to build consistent...... versioning field and GAIA is compared with previous attempts at defining hypermedia versioning frameworks. GAIA is capable of multi-level versioning and versioning of structures and supports freezing mechanisms for both documents and hyperstructure. The experiences from GAIA provide an input to new reference...

HYPERTEXT 98. The Proceedings of the Ninth ACM Conference on Hypertext and Hypermedia

DEFF Research Database (Denmark)

The Conference on Hypertext and Hypermedia brings together scholars, researchers, and practitioners from diverse disciplines to consider the form, role and impact of hypertext and hypermedia in a forum of discussion of ideas, design and use of hypertext and hypermedia in a variety of domains. The...

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

Science.gov (United States)

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

Perceived Value of Educational Hypermedia: An Exploratory Study

Science.gov (United States)

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…

Autonomy supported, learner-controlled or system-controlled learning in hypermedia environments and the influence of academic self-regulation style

NARCIS (Netherlands)

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

2012-01-01

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

Autonomy supported, learner-controlled or system-controlled learning in hypermedia environments and the influence of academic self-regulation style

NARCIS (Netherlands)

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

Merging the Internet and Hypermedia in the English Language Arts.

Science.gov (United States)

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…

Enhancing L2 Reading Comprehension with Hypermedia Texts: Student Perceptions

Science.gov (United States)

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…

Design dependencies within the automatic generation of hypermedia presentations

NARCIS (Netherlands)

O. Rosell Martinez

2002-01-01

textabstractMany dependencies appear between the different stages of the creation of a hypermedia presentation. These dependencies have to be taken into account while designing a system for their automatic generation. In this work we study two of them and propose some techniques to treat them.

Adaptive Social Learning Based on Crowdsourcing

Science.gov (United States)

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…

Exploring Metacognitive Strategies and Hypermedia Annotations on Foreign Language Reading

Science.gov (United States)

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…

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

Science.gov (United States)

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,…

Supporting Adaptive and Adaptable Hypermedia Presentation Semantics

NARCIS (Netherlands)

D.C.A. Bulterman (Dick); L. Rutledge (Lloyd); L. Hardman (Lynda); J.R. van Ossenbruggen (Jacco)

1999-01-01

textabstractHaving the content of a presentation adapt to the needs, resources and prior activities of a user can be an important benefit of electronic documents. While part of this adaptation is related to the encodings of individual data streams, much of the adaptation can/should be guided by the

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

Science.gov (United States)

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.

In-depth review of a large hypermedia-KBS engineering application

International Nuclear Information System (INIS)

Bogaerts. W.F.L.; Arents, H.C.; Thuy, V.T.

1991-01-01

The paper describes the use of advanced information systems in the area of corrosion and materials performance. It gives an overview of the functionalities of one of the largest hypermedia systems available in the area of materials engineering: the Active Library on Corrosion (ALC). This system has been developed for Elsevier Science Publishers in the framework of the European ESPRIT project ''Kwick''. (orig.)

Fluid annotations through open hypermedia: Using and extending emerging Web standards

DEFF Research Database (Denmark)

Bouvin, Niels Olof; Zellweger, Polle Trescott; Grønbæk, Kaj

2002-01-01

and browsing of fluid annotations on third-party Web pages. This prototype is an extension of the Arakne Environment, an open hypermedia application that can augment Web pages with externally stored hypermedia structures. This paper describes how various Web standards, including DOM, CSS, XLink, XPointer...

Clustering semantics for hypermedia presentation

NARCIS (Netherlands)

Alberink, M.J.; Rutledge, L.W.; Hardman, H.L.; Veenstra, M.J.A.

2004-01-01

Semantic annotations of media repositories make relationships among the stored media and relevant concepts explicit. However, these relationships and the media they join are not directly presentable as hypermedia. Previous work shows how clustering over the annotations in the repositories can

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

Science.gov (United States)

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…

Toward a Dexter-based model for open hypermedia: Unifying embedded references and link objects

DEFF Research Database (Denmark)

Grønbæk, Kaj; Trigg, Randall Hagner

1996-01-01

Nominated for the Doug Engelbart best paper award. This paper discusses experiences and lessons learned from the design of an open hypermedia system, one that integrates applications and data not ''owned'' by the hypermedia. The Dexter Hypertext Reference Model was used as the basis for the design....... Though our experiences were generally positive, we found the model constraining in certain ways and underdeveloped in others. For instance, Dexter argues against dangling links, but we found several situations where permitting and supporting dangling links was advisable. In Dexter, the data objects...

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

Science.gov (United States)

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…

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

Science.gov (United States)

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…

The Effects of Gender and Dominant Mental Processes on Hypermedia Learning

Science.gov (United States)

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…

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

Science.gov (United States)

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…

The Amsterdam Hypermedia Model: Adding Time and Context to the Dexter Model

NARCIS (Netherlands)

L. Hardman (Lynda); D.C.A. Bulterman (Dick); G. van Rossum (Guido)

1994-01-01

textabstractFrom Computing Reviews, by Jeanine Meyer The purpose of this paper is to convince the reader of the need for a general model for hypermedia and present the Amsterdam hypermedia model (AHM) as fulfilling that need. Hypertext, which is described by the authors as a 'relatively mature

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

Science.gov (United States)

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.…

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

Science.gov (United States)

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)

HyCon: A Framework for Context-aware Mobile Hypermedia

DEFF Research Database (Denmark)

Bouvin, Niels Olof; Christensen, Bent Guldbjerg; Grønbæk, Kaj

2003-01-01

be sensed automatically and/or be provided by the user directly. When mobile, the user may obtain context-aware hypermedia support on a variety of small and medium sized computing platforms such as mobile phones, PDAs, tablet PCs, and laptops. This paper introduces the HyCon (HyperContext) framework......This paper introduces the notion of context-aware mobile hypermedia. Context awareness means to take the users' context such as location, time, objective, community relations, etc., into account when browsing, searching, annotating, and linking. Attributes constituting the context of the user may...

Implementing Adaptive Educational Methods with IMS Learning Design

NARCIS (Netherlands)

Specht, Marcus; Burgos, Daniel

2006-01-01

Please, cite this publication as: Specht, M. & Burgos, D. (2006). Implementing Adaptive Educational Methods with IMS Learning Design. Proceedings of Adaptive Hypermedia. June, Dublin, Ireland. Retrieved June 30th, 2006, from http://dspace.learningnetworks.org

Computer Graphics for Multimedia and Hypermedia Development.

Science.gov (United States)

Mohler, James L.

1998-01-01

Discusses several theoretical and technical aspects of computer-graphics development that are useful for creating hypermedia and multimedia materials. Topics addressed include primary bitmap attributes in computer graphics, the jigsaw principle, and raster layering. (MSE)

Design issues in adaptive web-site development

NARCIS (Netherlands)

De Bra, P.M.E.; Brusilovsky, P.; De Bra, P.M.E.

1999-01-01

For almost a decade people have been developing hypertext or hypermedia applications that adapt to some "features" of their users, like knowledge or preferences [Brusilovsky, 1996]. Recently some adaptive application environments have become available that use World Wide Web technology. Examples of

Webvise: Browser and Proxy support for open hypermedia structuring mechanisms on the WWW

DEFF Research Database (Denmark)

Grønbæk, Kaj; Sloth, Lennard; Ørbæk, Peter

1999-01-01

Web pages. Support for providing links to/from parts of non-HTML data, such as sound and movie, will be possible via interfaces to plug-ins and Java-based media players. The hypermedia structures are stored in a hypermedia database, developed from the Devise Hypermedia framework, and the service...... be manipulated and used via special Java applets and a pure proxy server solution is provided for users who only need to browse the structures. A user can create and use the external structures as ‘transparency' layers on top of arbitrary Web pages, the user can switch between viewing pages with one or more...

Hypermedia-Based Problem Based Learning in the Upper Elementary Grades: A Developmental Study.

Science.gov (United States)

Brinkerhoff, Jonathan D.; Glazewski, Krista

This paper describes the application of problem-based learning (PBL) design principles and the inclusion of teacher and study scaffolds to the design and implementation of a hypermedia-based learning unit for the upper elementary/middle school grades. The study examined the following research questions: (1) Does hypermedia-based PBL represent an…

Contextualization in hypermedia news report: narrative and immersion

Directory of Open Access Journals (Sweden)

João Canavilhas

2015-09-01

Full Text Available The mobile journalism and, particularly, hypermedia stories get new possibilities for making narratives, boosted by the mobility itself, and also by the use of touchable screens, accelerometer, GPS receiver and permanent connection to the internet. Due to these potentials, tablets, smartphones and wearables reconfigure processes and journalistic narratives for the web. From this premise, the article focuses the research in hypermedia storytelling for mobile devices, aiming to observe how the hypertext resources are used in the contextualization of journalistic narratives published at mobile devices (tablets and smartphones. To achieve this aim, we realized a systematic analysis from newspaper editions of Globo A Mais journal for two months. This was done by selecting a case exemplifying the way the hypertext features can serve the contextualization.

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

Science.gov (United States)

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

Biochemical Hypermedia: Galactose Metabolism.

Directory of Open Access Journals (Sweden)

J.K. Sugai

2013-05-01

Full Text Available Introduction: Animations of biochemical processes and virtual laboratory environments lead to true molecular simulations. The use of interactive software’s in education can improve cognitive capacity, better learning and, mainly, it makes information acquisition easier. Material and Methods: This work presents the development of a biochemical hypermedia to understanding of the galactose metabolism. It was developed with the help of concept maps, ISIS Draw, ADOBE Photoshop and FLASH MX Program. Results and Discussion: A step by step animation process shows the enzymatic reactions of galactose conversion to glucose-1-phosphate (to glycogen synthesis, glucose-6-phosphate (glycolysis intermediary, UDP-galactose (substrate to mucopolysaccharides synthesis and collagen’s glycosylation. There are navigation guide that allow scrolling the mouse over the names of the components of enzymatic reactions of via the metabolism of galactose. Thus, explanatory text box, chemical structures and animation of the actions of enzymes appear to navigator. Upon completion of the module, the user’s response to the proposed exercise can be checked immediately through text box with interactive content of the answer. Conclusion: This hypermedia was presented for undergraduate students (UFSC who revealed that it was extremely effective in promoting the understanding of the theme.

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

Science.gov (United States)

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.

Ubiquitous Annotation Systems

DEFF Research Database (Denmark)

Hansen, Frank Allan

2006-01-01

Ubiquitous annotation systems allow users to annotate physical places, objects, and persons with digital information. Especially in the field of location based information systems much work has been done to implement adaptive and context-aware systems, but few efforts have focused on the general...... requirements for linking information to objects in both physical and digital space. This paper surveys annotation techniques from open hypermedia systems, Web based annotation systems, and mobile and augmented reality systems to illustrate different approaches to four central challenges ubiquitous annotation...... systems have to deal with: anchoring, structuring, presentation, and authoring. Through a number of examples each challenge is discussed and HyCon, a context-aware hypermedia framework developed at the University of Aarhus, Denmark, is used to illustrate an integrated approach to ubiquitous annotations...

Hypermedia for language learning: the FREE model at Coventry University

Directory of Open Access Journals (Sweden)

Marina Orsini-Jones

1996-12-01

Full Text Available The tradition of incorporating CALL into the language-learning curriculum goes back to the early 1980s at Coventry University, and since then has evolved in keeping with changes in the technology available (Corness 1984; Benwell 1986; Orsini-Jones 1987; Corness et al 1992; Orsini-Jones 1993. Coventry University is at present pioneering the integration of hypermedia into the curriculum for the teaching of Italian language and society. The syllabus for a complete module of the BA Modern Languages and BA European Studies Degrees, which will count as l/8th of the students' programme for year 2, has been designed upon in-house produced hypermedia courseware.

CEPIAH, a method for Evaluation and Design of Pedagogical Hypermedia

OpenAIRE

Trigano , Philippe; 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 tool integrates two modules such as EMPI (Evaluation of Multimedia Pedagogical and Interactive software), and SP/UL/FC, a method for designing pedagogical hypermedia. The EMPI module is used to evaluate multimedia software used in educational context. We structured a knowledge base composed of a list of evaluation criteria, grouped...

Building Hypermedia APIs with HTML5 and Node

CERN Document Server

Amundsen, Mike

2011-01-01

With this concise book, you'll learn the art of building hypermedia APIs that don't simply run on the Web, but that actually exist in the Web. You'll start with the general principles and technologies behind this architectural approach, and then dive hands-on into three fully-functional API examples. Too many APIs rely on concepts rooted in desktop and local area network patterns that don't scale well-costly solutions that are difficult to maintain over time. This book shows system architects and web developers how to design and implement human- and machine-readable web services that remain

Classical Hypermedia Virtues on the Web with Webstrates

DEFF Research Database (Denmark)

Bouvin, Niels Olof; Klokmose, Clemens Nylandsted

2016-01-01

We show and analyze herein how Webstrates can augment the Web from a classical hypermedia perspective. Webstrates turns the DOM of Web pages into persistent and collaborative objects. We demonstrate how this can be applied to realize bidirectional links, shared collaborative annotations, and in...

The Art of Multi-channel Hypermedia Application Development

NARCIS (Netherlands)

Synodinos, Dionysios G.; Avgeriou, Paris

2003-01-01

The plethora of networked devices and platforms that continuously come to light, as well as the emergence of alternative ways to access the internet, have increased the demand for multi-channel access to hypermedia applications. Researchers and practitioners nowadays not only have to deal with the

Developing educational hypermedia applications: a methodological approach

Directory of Open Access Journals (Sweden)

Jose Miguel Nunes

1996-01-01

Full Text Available This paper proposes an hypermedia development methodology with the aim of integrating the work of both educators, who will be primarily responsible for the instructional design, with that of software experts, responsible for the software design and development. Hence, it is proposed that the educators and programmers should interact in an integrated and systematic manner following a methodological approach.

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

Science.gov (United States)

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.

Specific Cooperative Analysis and Design in General Hypermedia Development

DEFF Research Database (Denmark)

Grønbæk, Kaj; Mogensen, Preben Holst

1994-01-01

activities. We demonstrate how these activities informed the general hypermedia framework and application design. Use scenarios and prototypes with example data from the users’ daily work were used as sources both to trigger design ideas and new insights regarding work practice. Mutual challenging...

Toward a Web based Environment for Evaluation and Design of Pedagogical Hypermedia

Directory of Open Access Journals (Sweden)

Ecaterina Pacurar-Giacomini

2004-07-01

Full Text Available 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 educational context. We structured a knowledge base composed from a list of evaluation criteria, grouped in six themes: general feeling, technical quality, usability, scenario, multimedia documents, and didactical aspects. We insisted on multimedia particular aspects: we thoroughly studied the specificity of multimedia documents (investigating various fields such as photography, typography, picture semantics, cinema…. We also evaluated the way multimedia elements are gathered to prepare the reading acts. We finally determined specific criteria for pedagogical aspects, associated to the previous approaches. A global questionnaire joins all these modules. In this paper, we present the first two modules, EMPI and SP/UL/FC ( a method for designing pedagogical hypermedia , and an application of distant teaching (and distant learning, commenting the first results of this experiment. We conclude by a short presentation of the third module, on which we are still working.

The effects of control versus autonomy in hypermedia learning environments

NARCIS (Netherlands)

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

2010-01-01

Gorissen, C. J. J., Kester, L., Brand-Gruwel, S., & Martens, R. L. (2010, 13-16 May). The effects of control versus autonomy in hypermedia learning environments. Poster presented at the 4th International Self-Determination Theory Conference, Ghent, Belgium: Kennisnet.

Using Hypermedia in Teaching Art & Design: Baroque Dutch Paintings

Directory of Open Access Journals (Sweden)

Inas A. Alkholy

2010-09-01

Full Text Available Although the whole world adapts ICT -information and communication technologies- in learning and teaching visual arts for the benefit of both the student and the society, the Middle East is motionless. ME teachers need training, institutional support and motivation to apply ICT in classrooms. Preparing a traditional lecture, including visual projected examples by data show takes less time. Doing comparisons and contrast, going through formal analysis or juggling between visual examples is complex within classrooms' technological limitations of having one projector. There is an urgent need to alter traditional methods of teaching art and design and integrate pictorial approaches. This paper discusses design/art pedagogy via a suggested model lesson, which utilizes hypermedia to resemble internet interface. The lesson teaches Dutch Baroque interior design through a selection of Vermeer's paintings. Vermeer accurately painted interior elements in his paintings. The development of technology stimulates students’ imagination and develops their understanding of more influencing graphical forms. Any other art and design themes and styles can be taught by using the same interface.

Developing Modular and Adaptable Courseware Using TeachML.

Science.gov (United States)

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…

QoS-based experience-aware adaptation in multimedia e-learning - A learner, is a learner, is a user, is a customer

OpenAIRE

Moebs, Sabine

2011-01-01

One of the challenges for the future of technology-enhanced learning is the retention of learners. On-line learning environments should engage learners and provide an appropriate “Quality of Experience” (QoE). For more than a decade, adaptive hypermedia systems have been used to adapt content and instruction to individual knowledge, goals and preferences in an effort to engage learners. However, even if the content is highly engaging it can be very difficult to achieve good Quality ...

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

Science.gov (United States)

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)

A Methodological Alternative to Media Comparison Studies: Linking Information Utilization Strategies and Instructional Approach in Hypermedia Learning

OpenAIRE

Catrambone, Richard; Gerjets, Peter; Scheiter, Katharina; Vollmann, Brigitte

2006-01-01

Literature reviews on hypermedia learning have yet failed to show consistent positive effects of learner-controlled nonlinear information access. We argue that a possible reason for this lack of evidence in favor of hypermedia learning results from the fact that not sufficient attention is paid to the strategies of information utilization learners deploy. The few studies that do analyze these strategies fail to link them to an instructional approach, which hampers a deeper interpretation of s...

A Model of an Expanded-Frame Hypermedia Knowledge-Base for Instruction.

Science.gov (United States)

Lacy, Mark J.; Wood, R. Kent

1993-01-01

Argues that current computer-based instruction does not exploit the instructional possibilities of computers. Critiques current models of computer-based instruction: behaviorist as too linear and constructivist as too unstructured. Offers a design model of Expanded-frame Hypermedia Knowledge-bases as an instructional approach allowing hypermedia…

Predictors of Foreign Language Reading Comprehension in a Hypermedia Reading Environment

Science.gov (United States)

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…

Interoperable adaptive educational hypermedia : a web service definition

NARCIS (Netherlands)

Meccawy, M.; Celik, I.; Cristea, A.I.; Stewart, C.; Ashman, H.; Kinshuk, xx; Koper, R.; Kommers, P.A.M.

2006-01-01

This paper presents an approach to resolve the problem of authoring and interchanging educational material, based on web services. Here we describe the ultimate goal, of reusing and interchanging freely adaptive elearning material, shortly sketch previous solutions, showing their benefits but also

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

Science.gov (United States)

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…

WiBAF into a CMS: personalization in learning environments made easy

NARCIS (Netherlands)

Montes Garcia, Aleandro; Stash, Natalia; Fabri, Marc; De Bra, Paul; Fletcher, George H.L.; Pechenizkiy, Mykola; Cena, F.; Desmarais, M.; Dicheva, D.; Zhang, J.

2016-01-01

Adaptivity has proven successful in reducing navigation and comprehension problems in hypermedia documents. Authoring of adaptive hypermedia documents and especially of the adaptivity in these documents has been problematic or at least labour intensive throughout AH history. This paper shows how the

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

Science.gov (United States)

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.

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

Science.gov (United States)

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…

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

Science.gov (United States)

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…

Proceedings of the 22nd ACM conference on Hypertext and hypermedia

DEFF Research Database (Denmark)

and Ubiquitous Hypermedia, chaired by Niels Olof Bouvin and Frank Shipman; Social Media (Linking People and Things), chaired by Andreas Hotho, Gerd Stumme and Markus Strohmaier; Interaction, Narrative, and Storytelling, chaired by Mark Bernstein and Frank Nack. Three keynote speakers represent the breadth, depth....... Noshir Contractor investigates factors that lead to the formation, maintenance and dissolution of dynamically linked social and knowledge networks. The Program Committee and the reviewers worked hard to select an excellent program from 104 paper submissions. We accepted 31 full papers and 4 short papers...

Shaping the Ambience of Homes with Domestic Hypermedia

DEFF Research Database (Denmark)

Grønbæk, Kaj; Petersen, Marianne Graves

2004-01-01

We currently witness a massive digitization of domestic materials e.g. photos, music, calendars, recipes, notes, messages. This digitization provides new conditions for how we interact with materials as well as how users shape the ambience of their homes. Observing the qualities of physical...... materials in the home, the process of digitization risks loosing the qualities of the spatial distribution, the aesthetics, and common reference points offered by physical materials and places in the home. We present a concept of domestic hypermedia (DoHM), which exploits potentials of digital materials...... and at the same time allow people to interact with digital materials in engaging ways providing rich experiences when organizing and using digital materials in homes. We present an infrastructure and design concepts that offer: ambient access to digital materials, common reference points, and collective...

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

Science.gov (United States)

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

Addressing Interoperability in Open Hypermedia: The Design of the Open Hypermedia Protocol

DEFF Research Database (Denmark)

Grønbæk, Kaj; Reich, Siegfried; Wiil, Uffe K.

1999-01-01

Early hypertext systems were monolithic and closed, but newer systems tend to be open, distributed, and support collaboration. While this development has resulted in increased openness and flexibility, integration or adaptation of various different tools (such as content editors, viewers, services...

Development and Evaluation of Internet-Based Hypermedia Chemistry Tutorials

Science.gov (United States)

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

Interactive hypermedia training manual for spent-fuel bundle counters

International Nuclear Information System (INIS)

Basso, R.A.

1990-07-01

Spent-fuel bundle counters, developed by the Canadian Safeguards Support Program for the International Atomic Energy Agency, provide a secure and independent means of counting the number of irradiated fuel bundles discharged into the fuel storage bays at CANDU nuclear power stations. Paper manuals have been traditionally used to familiarize IAEA inspectors with the operation, maintenance and extensive reporting capabilities of the bundle counters. To further assist inspectors, an interactive training manual has been developed on an Apple Macintosh computer using hypermedia software. The manual uses interactive animation and sound, in conjunction with the traditional text and graphics, to simulate the underlying operation and logic of the bundle counters. This paper presents the key features of the interactive manual and highlights the advantages of this new technology for training

Learning Mediated by an Educational Hypermedia

Science.gov (United States)

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.

Individualized Special Education with Cognitive Skill Assessment.

Science.gov (United States)

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.…

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

Science.gov (United States)

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…

Adaptation in Living Systems

Science.gov (United States)

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.

Dynamic Learning Style Prediction Method Based on a Pattern Recognition Technique

Science.gov (United States)

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…

HT 2011 : Proceedings of the 22nd ACM Conference on Hypertext and Hypermedia, Eindhoven, The Netherlands, June 6-9, 2011

NARCIS (Netherlands)

De Bra, P.M.E.; Gronbak, K.

2011-01-01

Foreword. It is our great pleasure to welcome you to ACM Hypertext 2011, the 22nd ACM Conference on Hypertext and Hypermedia, and to the "Land of the Innovator", the campus of the Eindhoven University of Technology, located in the "city of light" Eindhoven, the Netherlands. Hypertext is an exciting

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

Science.gov (United States)

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…

University Mentoring with the Support of a Digital Pen and Hypermedia Resources

Directory of Open Access Journals (Sweden)

Manuel Francisco Aguilar Tamayo

2014-12-01

Full Text Available This paper systematizes face-to-face tutoring experience and the use of technologies to make audio and written recordings of tutorial sessions with undergraduate, master’s and doctoral students available online. One hundred and three tutorial sessions with 26 students and a single tutor are analyzed; the sessions were recorded by means of a digital pen that recorded sound and writing synchronously. By means of this analysis students’ issues and problems were identified and a model for connecting teaching strategy and the production of hypermedia resources is presented. We contend that it is important to create learning resources to accompany the educational process of tutees. In conclusion the study presents a model for organizing and supporting university level tutoring.

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

Science.gov (United States)

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

Adaptivity in Professional Printing Systems

NARCIS (Netherlands)

Verriet, J.H.; Basten, T; Hamberg, R.; Reckers, F.J.; Somers, L.

2013-01-01

There is a constant pressure on developers of embedded systems to simultaneously increase system functionality and to decrease development costs. Aviable way to obtain a better system performance with the same physical hardware is adaptivity: a system should be able to adapt itself to dynamically

Farming System Evolution and Adaptive Capacity: Insights for Adaptation Support

Directory of Open Access Journals (Sweden)

Jami L. Dixon

2014-02-01

Full Text Available Studies of climate impacts on agriculture and adaptation often provide current or future assessments, ignoring the historical contexts farming systems are situated within. We investigate how historical trends have influenced farming system adaptive capacity in Uganda using data from household surveys, semi-structured interviews, focus-group discussions and observations. By comparing two farming systems, we note three major findings: (1 similar trends in farming system evolution have had differential impacts on the diversity of farming systems; (2 trends have contributed to the erosion of informal social and cultural institutions and an increasing dependence on formal institutions; and (3 trade-offs between components of adaptive capacity are made at the farm-scale, thus influencing farming system adaptive capacity. To identify the actual impacts of future climate change and variability, it is important to recognize the dynamic nature of adaptation. In practice, areas identified for further adaptation support include: shift away from one-size-fits-all approach the identification and integration of appropriate modern farming method; a greater focus on building inclusive formal and informal institutions; and a more nuanced understanding regarding the roles and decision-making processes of influential, but external, actors. More research is needed to understand farm-scale trade-offs and the resulting impacts across spatial and temporal scales.

Turbine system and adapter

Science.gov (United States)

Hogberg, Nicholas Alvin; Garcia-Crespo, Andres Jose

2017-05-30

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 rotor 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.

Complex Adaptive Systems of Systems (CASOS) engineering environment.

Energy Technology Data Exchange (ETDEWEB)

Detry, Richard Joseph; Linebarger, John Michael; Finley, Patrick D.; Maffitt, S. Louise; Glass, Robert John, Jr.; Beyeler, Walter Eugene; Ames, Arlo Leroy

2012-02-01

Complex Adaptive Systems of Systems, or CASoS, are vastly complex physical-socio-technical systems which we must understand to design a secure future for the nation. The Phoenix initiative implements CASoS Engineering principles combining the bottom up Complex Systems and Complex Adaptive Systems view with the top down Systems Engineering and System-of-Systems view. CASoS Engineering theory and practice must be conducted together to develop a discipline that is grounded in reality, extends our understanding of how CASoS behave and allows us to better control the outcomes. The pull of applications (real world problems) is critical to this effort, as is the articulation of a CASoS Engineering Framework that grounds an engineering approach in the theory of complex adaptive systems of systems. Successful application of the CASoS Engineering Framework requires modeling, simulation and analysis (MS and A) capabilities and the cultivation of a CASoS Engineering Community of Practice through knowledge sharing and facilitation. The CASoS Engineering Environment, itself a complex adaptive system of systems, constitutes the two platforms that provide these capabilities.

The Ash Soap making in the state of Minas Gerais, Brazil: from the status of ethnoscience to its mediation for the classroom using an ethnographic hypermedia system

Directory of Open Access Journals (Sweden)

Paulo César Pinheiro

2010-11-01

Full Text Available The ash soap making process developed by women from the interior of the state of Minas Gerais, Brazil, is described and analyzed in order to typify it as ethnoscience. Some of the major conceptions related to folk knowledge, ethnoscience and the chemistry of saponification are presented in order to justify this enterprise. The theoretical and methodological aspects of the ethnographic research carried out with the group of women investigated is discussed and an approximation between the knowledge of these women, the Chemistry knowledge and that of the students of the secondary level is proposed by means of an ethnographic hypermedia as mediational mean for the classroom.

Model-based design of adaptive embedded systems

CERN Document Server

Hamberg, Roelof; Reckers, Frans; Verriet, Jacques

2013-01-01

Today’s embedded systems have to operate in a wide variety of dynamically changing environmental circumstances. Adaptivity, the ability of a system to autonomously adapt itself, is a means to optimise a system’s behaviour to accommodate changes in its environment. It involves making in-product trade-offs between system qualities at system level. The main challenge in the development of adaptive systems is keeping control of the intrinsic complexity of such systems while working with multi-disciplinary teams to create different parts of the system. Model-Based Development of Adaptive Embedded Systems focuses on the development of adaptive embedded systems both from an architectural and methodological point of view. It describes architectural solution patterns for adaptive systems and state-of-the-art model-based methods and techniques to support adaptive system development. In particular, the book describes the outcome of the Octopus project, a cooperation of a multi-disciplinary team of academic and indus...

Expert systems for the transportation of hazardous and radioactive materials

International Nuclear Information System (INIS)

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

1994-01-01

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

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

Science.gov (United States)

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

User interaction in modern web information systems

NARCIS (Netherlands)

Barna, P.; Houben, G.J.P.M.; De Bra, P.M.E.

2003-01-01

Modern Information Systems based on Web technologies (Web-based Information Systems - WIS) typically generate hypermedia presentations according to the user needs. Hera is our model-driven methodology specifying the design cycle and the architecture framework for WIS. To avoid additional expensive

Adaptive security systems -- Combining expert systems with adaptive technologies

International Nuclear Information System (INIS)

Argo, P.; Loveland, R.; Anderson, K.

1997-01-01

The Adaptive Multisensor Integrated Security System (AMISS) uses a variety of computational intelligence techniques to reason from raw sensor data through an array of processing layers to arrive at an assessment for alarm/alert conditions based on human behavior within a secure facility. In this paper, the authors give an overview of the system and briefly describe some of the major components of the system. This system is currently under development and testing in a realistic facility setting

Computerized adaptive testing item selection in computerized adaptive learning systems

NARCIS (Netherlands)

Eggen, Theodorus Johannes Hendrikus Maria; Eggen, T.J.H.M.; Veldkamp, B.P.

2012-01-01

Item selection methods traditionally developed for computerized adaptive testing (CAT) are explored for their usefulness in item-based computerized adaptive learning (CAL) systems. While in CAT Fisher information-based selection is optimal, for recovering learning populations in CAL systems item

Adaptive control of port-Hamiltonian systems

NARCIS (Netherlands)

Dirksz, D.A.; Scherpen, J.M.A.; Edelmayer, András

2010-01-01

In this paper an adaptive control scheme is presented for general port-Hamiltonian systems. Adaptive control is used to compensate for control errors that are caused by unknown or uncertain parameter values of a system. The adaptive control is also combined with canonical transformation theory for

FEATURES OF LOGISTIC SYSTEM ADAPTIVE MANAGEMENT

Directory of Open Access Journals (Sweden)

Natalya VOZNENKO

2015-08-01

Full Text Available The study presents literature survey on enterprise logistic system adaptive management place and structure in the general enterprise management system. The theoretical basics of logistic system functioning, levels of its management and its effectiveness had been investigated. The role of adaptive management and its types had been scrutinized. The necessity of creating company’s adaptive regulator such as its economic mechanism had been proved.

Adaptation in CRISPR-Cas Systems.

Science.gov (United States)

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.

Informatics and Society: The Challenge of Improving IT Accessibility

Directory of Open Access Journals (Sweden)

Bruce Diamond

2005-12-01

Full Text Available Information technology (IT is an important part of society and has assumed an increasing role in education, medicine, commercial, leisure, and sociopolitical applications. However, while progress in developing IT hardware and software has advanced, our understanding of user needs and how these needs can be translated into more accessible and effective system design lags behind. The challenge that we face is rooted in the fact that many individuals across this planet who are differently-abled due to aging, developmental or neurologic conditions or to individual differences in learning, face obstacles in using and accessing IT. The central thesis of this paper is that the effective delivery of IT to the differently-abled is contingent on deriving enough information about user populations to allow for the development and use of personalized interfaces and customized content. To this end, it is proposed that a combination of adaptive hypermedia and cognitive adaptive strategies integrating metadata architecture for representing the results of cognitive and functional assessments be designed and implemented. Keywords: Information technology, accessibility, differently-abled, adaptive hypermedia, informatics

Mobile Learning in Context — Context-aware Hypermedia in the Wild

DEFF Research Database (Denmark)

Hansen, Frank Allan; Bouvin, Niels Olof

2009-01-01

Modern project-based education requires students to be able to work with digital materials both in and out of the classroom. Field trips are often an integral part of such projects and greatly benefit students' learning by allowing them to engage with real-world environments first-hand. However......, the infrastructure for accessing context sensitive information and supporting in-situ authoring by students while in the field is often lacking. In this paper we present the HyCon framework for mobile, context-aware, and multi-platform hypermedia that aims at supporting several aspects of fieldtrips and project...

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

Science.gov (United States)

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

Self-Adaptive Systems for Machine Intelligence

CERN Document Server

He, Haibo

2011-01-01

This book will advance the understanding and application of self-adaptive intelligent systems; therefore it will potentially benefit the long-term goal of replicating certain levels of brain-like intelligence in complex and networked engineering systems. It will provide new approaches for adaptive systems within uncertain environments. This will provide an opportunity to evaluate the strengths and weaknesses of the current state-of-the-art of knowledge, give rise to new research directions, and educate future professionals in this domain. Self-adaptive intelligent systems have wide application

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

Energy Technology Data Exchange (ETDEWEB)

Gauthier, John H. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). System Readiness & Sustainment Technologies (6133, M/S 1188); Miner, Nadine E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Military & Energy Systems Analysis (6114, M/S 1188); Wilson, Michael L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Resilience and Regulatory Effects (6921, M/S 1138); Le, Hai D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). System Readiness & Sustainment Technologies (6133, M/S 1188); Kao, Gio K. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Networked System Survivability & Assurance (5629, M/S 0671); Melander, Darryl J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Software Systems R& D (9525, M/S 1188); Longsine, Dennis Earl [Sandia National Laboratories, Unknown, Unknown; Vander Meer, Jr., Robert C. [SAIC, Inc., Albuquerque, NM (United States)

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 combining 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.

Hypermedia in the Kimura System

DEFF Research Database (Denmark)

MacIntyre, Blair; Mynatt, Elizabeth Diane; Voida, Steve

2001-01-01

The goal of the Kimura system is to augment traditional office computing environments in order to explore and evaluate the addition of visual peripheral displays to human-computer interfaces within an office environment. To do this, we employ multiple peripheral dispalys to display spatial, tempo...

Environmentally-adapted local energy systems

Energy Technology Data Exchange (ETDEWEB)

Moe, N; Oefverholm, E [NUTEK, Stockholm (Sweden); Andersson, Owe [EKAN Gruppen (Sweden); Froste, H [Swedish Environmental Protection Agency, Stockholm (Sweden)

1997-10-01

Energy companies, municipalities, property companies, firms of consultants, environmental groups and individuals are examples of players working locally to shape environmentally adapted energy systems. These players have needed information making them better able to make decisions on cost-efficient, environmentally-adapted energy systems. This book answers many of the questions they have put. The volume is mainly based on Swedish handbooks produced by the Swedish National Board for Industrial and Technical Development, NUTEK, together with the Swedish Environmental Protection Agency. These handbooks have been used in conjunction with municipal energy planning, local Agenda 21 work, to provide a basis for deciding on concrete local energy systems. The contents in brief: -The book throws new light on the concept of energy efficiency; -A section on the environment compares how air-polluting emissions vary with different methods of energy production; -A section contains more than 40 ideas for measures which can be profitable, reduce energy consumption and the impact on the environment all at the same time; -The book gives concrete examples of new, alternative and environmentally-adapted local energy systems. More efficient use of energy is included as a possible change of energy system; -The greatest emphasis is laid upon alternative energy systems for heating. It may be heating in a house, block of flats, office building or school; -Finally, there are examples of environmentally-adapted local energy planning.

Engineering semantic web information systems in Hera

NARCIS (Netherlands)

Vdovják, R.; Frasincar, F.; Houben, G.J.P.M.; Barna, P.

2003-01-01

The success of the World Wide Web has caused the concept of information system to change. Web Information Systems (WIS) use from the Web its paradigm and technologies in order to retrieve information from sources on the Web, and to present the information in terms of a Web or hypermedia

Nonequilibrium Enhances Adaptation Efficiency of Stochastic Biochemical Systems.

Directory of Open Access Journals (Sweden)

Chen Jia

Full Text Available Adaptation is a crucial biological function possessed by many sensory systems. Early work has shown that some influential equilibrium models can achieve accurate adaptation. However, recent studies indicate that there are close relationships between adaptation and nonequilibrium. In this paper, we provide an explanation of these two seemingly contradictory results based on Markov models with relatively simple networks. We show that as the nonequilibrium driving becomes stronger, the system under consideration will undergo a phase transition along a fixed direction: from non-adaptation to simple adaptation then to oscillatory adaptation, while the transition in the opposite direction is forbidden. This indicates that although adaptation may be observed in equilibrium systems, it tends to occur in systems far away from equilibrium. In addition, we find that nonequilibrium will improve the performance of adaptation by enhancing the adaptation efficiency. All these results provide a deeper insight into the connection between adaptation and nonequilibrium. Finally, we use a more complicated network model of bacterial chemotaxis to validate the main results of this paper.

Recommendation System for Adaptive Learning.

Science.gov (United States)

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.

Changing Paradigms: From Schooling to Schools as Adaptive Recommendation Systems

DEFF Research Database (Denmark)

Christiansen, René Boyer; Gynther, Karsten; Petersen, Anne Kristine

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 system has used and understood adaptation. In this context, we point out two different approaches to educational adaptation: 1) students adapting to the educational system and 2) the attempt of the educational system to adapt to students through automatized...... system adaptation and recommendation systems. These different understandings constitute a design framework that is used to analyze two current trends: Adaptive learning systems and learning analytics. Finally, the paper discusses the potential of looking at adaptation as recommendation systems...

Changing Paradigms: From Schooling to Schools as Adaptive Recommendation Systems

DEFF Research Database (Denmark)

Christiansen, René Boyer; Gynther, Karsten; Petersen, Anne Kristine

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...... system adaptation and recommendation systems. These different understandings constitute a design framework that is used to analyze two current trends: Adaptive learning systems and learning analytics. Finally, the paper discusses the potential of looking at adaptation as recommendation systems...... Foerster to shed light on how the educational system has used and understood adaptation. In this context, we point out two different approaches to educational adaptation: 1) students adapting to the educational system and 2) the attempt of the educational system to adapt to students through automatized...

Design Specifications for Adaptive Real-Time Systems

Science.gov (United States)

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

Student Modelling in Adaptive E-Learning Systems

Directory of Open Access Journals (Sweden)

Clemens Bechter

2011-09-01

Full Text Available Most e-Learning systems provide web-based learning so that students can access the same online courses via the Internet without adaptation, based on each student's profile and behavior. In an e-Learning system, one size does not fit all. Therefore, it is a challenge to make e-Learning systems that are suitably “adaptive”. The aim of adaptive e-Learning is to provide the students the appropriate content at the right time, means that the system is able to determine the knowledge level, keep track of usage, and arrange content automatically for each student for the best learning result. This study presents a proposed system which includes major adaptive features based on a student model. The proposed system is able to initialize the student model for determining the knowledge level of a student when the student registers for the course. After a student starts learning the lessons and doing many activities, the system can track information of the student until he/she takes a test. The student’s knowledge level, based on the test scores, is updated into the system for use in the adaptation process, which combines the student model with the domain model in order to deliver suitable course contents to the students. In this study, the proposed adaptive e-Learning system is implemented on an “Introduction to Java Programming Language” course, using LearnSquare software. After the system was tested, the results showed positive feedback towards the proposed system, especially in its adaptive capability.

Adaptive lag synchronization and parameters adaptive lag identification of chaotic systems

Energy Technology Data Exchange (ETDEWEB)

Xu Yuhua, E-mail: yuhuaxu2004@163.co [College of Information Science and Technology, Donghua University, Shanghai 201620 (China) and Department of Mathematics, Yunyang Teachers' College, Hubei, Shiyan 442000 (China); Zhou Wuneng, E-mail: wnzhou@163.co [College of Information Science and Technology, Donghua University, Shanghai 201620 (China) and Key Laboratory of Wireless Sensor Network and Communication, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Fang Jian' an, E-mail: jafang@dhu.edu.c [College of Information Science and Technology, Donghua University, Shanghai 201620 (China); Sun Wen, E-mail: sunwen_2201@163.co [School of Mathematics and Information, Yangtze University, Hubei, Jingzhou 434023 (China)

2010-07-26

This Letter investigates the problem of adaptive lag synchronization and parameters adaptive lag identification of chaotic systems. In comparison with those of existing parameters identification schemes, the unknown parameters are identified by adaptive lag laws, and the delay time is also identified in this Letter. Numerical simulations are also given to show the effectiveness of the proposed method.

Rate Adaptive OFDMA Communication Systems

International Nuclear Information System (INIS)

Abdelhakim, M.M.M.

2009-01-01

Due to the varying nature of the wireless channels, adapting the transmission parameters, such as code rate, modulation order and power, in response to the channel variations provides a significant improvement in the system performance. In the OFDM systems, Per-Frame adaptation (PFA) can be employed where the transmission variables are fixed over a given frame and may change from one frame to the other. Subband (tile) loading offers more degrees of adaptation such that each group of carriers (subband) uses the same transmission parameters and different subbands may use different parameters. Changing the code rate for each tile in the same frame, results in transmitting multiple codewords (MCWs) for a single frame. In this thesis a scheme is proposed for adaptively changing the code rate of coded OFDMA systems via changing the puncturing rate within a single codeword (SCW). In the proposed structure, the data is encoded with the lowest available code rate then it is divided among the different tiles where it is punctured adaptively based on some measure of the channel quality for each tile. The proposed scheme is compared against using multiple codewords (MCWs) where the different code rates for the tiles are obtained using separate encoding processes. For bit interleaved coded modulation architecture two novel interleaving methods are proposed, namely the puncturing dependant interleaver (PDI) and interleaved puncturing (IntP), which provide larger interleaving depth. In the PDI method the coded bits with the same rate over different tiles are grouped for interleaving. In IntP structure the interleaving is performed prior to puncturing. The performance of the adaptive puncturing technique is investigated under constant bit rate constraint and variable bit rate. Two different adaptive modulation and coding (AMC) selection methods are examined for variable bit rate adaptive system. The first is a recursive scheme that operates directly on the SNR whereas the second

DySOA : Making service systems self-adaptive

NARCIS (Netherlands)

Siljee, J; Bosloper, [No Value; Nijhuis, J; Hammer, D; Benatallah, B; Casati, F; Traverso, P

2005-01-01

Service-centric systems exist in a very dynamic environment. This requires these systems to adapt at runtime in order to keep fulfilling their QoS. In order to create self-adaptive service systems, developers should not only design the service architecture, but also need to design the

Une architecture générique de Systèmes de recommandation de combinaison d'items : application au domaine du tourisme

OpenAIRE

Picot-Clémente , Romain

2011-01-01

This thesis gives a generalization of the recommendation principle of recommender systems. Instead of considering a recommendation as an item, it is considered as a combination of several items following a given pattern. A recommendation of a unique item is then a particular case of this type of recommendation. The proposed recommender system framework is based on an architecture derived from work in adaptive hypermedia systems. Three layers are defined: a semantic layer, a user layer and an ...

Operator adaptation to changes in system reliability under adaptable automation.

Science.gov (United States)

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.

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

Science.gov (United States)

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…

Development of an expert system for transportation of hazardous and radioactive materials

International Nuclear Information System (INIS)

Ferrada, J.J.; Michelhaugh, R.D.; Rawl, R.R.

1994-01-01

Under the sponsorship of the US Department of Energy's (DOE's) Transportation Management Division (EM-261), the Transportation Technologies Group at Oak Ridge National Laboratory (ORNL) has designed and developed an expert system prototype application of the hazardous materials transportation regulations. The objective of this task was to provide a proof-of-concept for developing a computerized expert system that will ensure straightforward, consistent, and error-free application of the hazardous materials transportation regulations. The expert system prototype entailed the analysis of what an expert in hazardous materials shipping information could/should do. From the analysis of the different features required for the expert system prototype, it was concluded that the developmental efforts should be directed to a Windows trademark 3.1 hypermedia environment. Hypermedia technology usually works as an interactive software system that gives personal computer users the ability to organize, manage, and present information in a number of formats--text, graphics, sound, and full-motion video

Adaptive protection algorithm and system

Science.gov (United States)

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.

Specification and Generation of Adapters for System Integration

NARCIS (Netherlands)

Mooij, A.J.; Voorhoeve, M.

2013-01-01

Large systems-of-systems are developed by integrating several smaller systems that have been developed independently. System integration often requires adaptation mechanisms for bridging any technical incompatibilities between the systems. In order to develop adapters in a faster way, we study ways

Adaptive feedback synchronization of Lue system

International Nuclear Information System (INIS)

Han, X.; Lu, J.-A.; Wu, X.

2004-01-01

This letter further improves and extends the works of Chen and Lue [Chaos, Solitons and Fractals 14 (2002) 643] and Wang et al. [Phys. Lett. A 312 (2003) 34]. In detail, the linear feedback synchronization and adaptive feedback synchronization for Lue system are discussed. And the lower bound of the feedback gain in linear feedback synchronization is presented. The adaptive feedback synchronization with only one controller is designed, which improves the proof in the work by Wang et al. The adaptive synchronization with two controllers for completely uncertain Lue system is also discussed, which extends the work of Chen and Lue. Also, numerical simulations show the effectiveness of these methods

Adaptive Sliding Mode Observer for a Class of Systems

OpenAIRE

D.Elleuch; T.Damak

2010-01-01

In this paper, the performance of two adaptive observers applied to interconnected systems is studied. The nonlinearity of systems can be written in a fractional form. The first adaptive observer is an adaptive sliding mode observer for a Lipchitz nonlinear system and the second one is an adaptive sliding mode observer having a filtered error as a sliding surface. After comparing their performances throughout the inverted pendulum mounted on a car system, it was shown tha...

Model-Based Design of Adaptive Embedded Systems

NARCIS (Netherlands)

Basten, T.; Hamberg, R.; Reckers, F.; Verriet, J.

2013-01-01

Today’s embedded systems have to operate in a wide variety of dynamically changing environmental circumstances. Adaptivity, the ability of a system to autonomously adapt itself, is a means to optimise a system’s behaviour to accommodate changes in its environment. It involves making in-product

Adaptive control system having hedge unit and related apparatus and methods

Science.gov (United States)

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

2007-01-01

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.

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

Science.gov (United States)

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...

Managing Schools as Complex Adaptive Systems: A Strategic Perspective

Science.gov (United States)

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…

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

Science.gov (United States)

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...

CMAC-based adaptive backstepping synchronization of uncertain chaotic systems

International Nuclear Information System (INIS)

Lin, C.-M.; Peng, Y.-F.; Lin, M.-H.

2009-01-01

This study proposes an adaptive backstepping control system for synchronizing uncertain chaotic system by using cerebellar model articulation controller (CMAC). CMAC is a nonlinear network with simple computation, good generalization capability and fast learning property. The proposed CMAC-based adaptive backstepping control (CABC) system uses backstepping method and adaptive cerebellar model articulation controller (ACMAC) for synchronizing uncertain chaotic system. Finally, simulation results for the Genesio system are presented to illustrate the effectiveness of the proposed control system.

Managing adaptively for multifunctionality in agricultural systems.

Science.gov (United States)

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

Managing adaptively for multifunctionality in agricultural systems

Science.gov (United States)

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

Self-Adaptive On-Chip System Based on Cross-Layer Adaptation Approach

Directory of Open Access Journals (Sweden)

Kais Loukil

2013-01-01

Full Text Available The emergence of mobile and battery operated multimedia systems and the diversity of supported applications mount new challenges in terms of design efficiency of these systems which must provide a maximum application quality of service (QoS in the presence of a dynamically varying environment. These optimization problems cannot be entirely solved at design time and some efficiency gains can be obtained at run-time by means of self-adaptivity. In this paper, we propose a new cross-layer hardware (HW/software (SW adaptation solution for embedded mobile systems. It supports application QoS under real-time and lifetime constraints via coordinated adaptation in the hardware, operating system (OS, and application layers. Our method relies on an original middleware solution used on both global and local managers. The global manager (GM handles large, long-term variations whereas the local manager (LM is used to guarantee real-time constraints. The GM acts in three layers whereas the LM acts in application and OS layers only. The main role of GM is to select the best configuration for each application to meet the constraints of the system and respect the preferences of the user. The proposed approach has been applied to a 3D graphics application and successfully implemented on an Altera FPGA.

Visual Cues for an Adaptive Expert System.

Science.gov (United States)

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…

THE EFFECTS OF PBL METHOD USING THE HYPERMEDIA TO THE STUDENTS’ CRITICAL THINKING SKILL ON THE SOCIAL STUDIES SUBJECT

Directory of Open Access Journals (Sweden)

Dicky Iranto

2014-10-01

Full Text Available Education as human’s process to gain knowledge is very important to create thinking skill for the human being. Related to that thing, implemented the learning with Problem Based Learning method which is the learning that is oriented to enhance the students’ critical thinking skill. In the constructivism learning theory, the students should be able to construct the knowledge through problem solving so they got the truth which is useful for the existence. This research is using the quasi experiment method with non-equivalent group design. The conclusion of this research shows that there is enhancement to the students’ critical thinking skill significantly and suggested to use this method on another topic, schools gives the hypermedia facilities, and researching another learning competences.

Relational adaptivity - enacting human-centric systems design

DEFF Research Database (Denmark)

Petersen, Kjell Yngve

2016-01-01

Human centered design approaches places the experiencing human at the center of concern, situated in relation to the dynamics of the environmental condition and the variables of the system of control and sensing. Taking the approach of enacted design methods to enforce the experience...... of the inhabitant as core in human-centered design solutions, the intelligence of the connected sensors is suggested to be developed as an actual learning and self-adjusting adaptive environment, where the adaptive system is part of a negotiation with users on the qualities of the environment. We will present...... a fully functional sketching environment for adaptive sensor-control systems, which enable integration of the complex situation of everyday activities and human well-being. The proposed sketching environment allows for the development of sensor systems related to lighting conditions and human occupancy...

MUCH Electronic Publishing Environment: Principles and Practices.

Science.gov (United States)

Min, Zheng; Rada, Roy

1994-01-01

Discusses the electronic publishing system called Many Using and Creating Hypermedia (MUCH). The MUCH system supports collaborative authoring; reuse; formatting and printing; management; hypermedia publishing and delivery; and interchange. This article examines electronic publishing environments; the MUCH environment; publishing activities; and…

Adaptive intrusion data system

International Nuclear Information System (INIS)

Johnson, C.S.

1976-01-01

An Adaptive Intrusion Data System (AIDS) was developed to collect data from intrusion alarm sensors as part of an evaluation system to improve sensor performance. AIDS is a unique digital data compression, storage, and formatting system. It also incorporates capability for video selection and recording for assessment of the sensors monitored by the system. The system is software reprogrammable to numerous configurations that may be utilized for the collection of environmental, bi-level, analog and video data. The output of the system is digital tapes formatted for direct data reduction on a CDC 6400 computer, and video tapes containing timed tagged information that can be correlated with the digital data

Adaptive traffic control systems for urban networks

Directory of Open Access Journals (Sweden)

Radivojević Danilo

2017-01-01

Full Text Available Adaptive traffic control systems represent complex, but powerful tool for improvement of traffic flow conditions in locations or zones where applied. Many traffic agencies, especially those that have a large number of signalized intersections with high variability of the traffic demand, choose to apply some of the adaptive traffic control systems. However, those systems are manufactured and offered by multiple vendors (companies that are competing for the market share. Due to that fact, besides the information available from the vendors themselves, or the information from different studies conducted on different continents, very limited amount of information is available about the details how those systems are operating. The reason for that is the protecting of the intellectual property from plagiarism. The primary goal of this paper is to make a brief analysis of the functionalities, characteristics, abilities and results of the most recognized, but also less known adaptive traffic control systems to the professional public and other persons with interest in this subject.

Complex and Adaptive Dynamical Systems A Primer

CERN Document Server

Gros, Claudius

2011-01-01

We are living in an ever more complex world, an epoch where human actions can accordingly acquire far-reaching potentialities. Complex and adaptive dynamical systems are ubiquitous in the world surrounding us and require us to adapt to new realities and the way of dealing with them. This primer has been developed with the aim of conveying a wide range of "commons-sense" knowledge in the field of quantitative complex system science at an introductory level, providing an entry point to this both fascinating and vitally important subject. The approach is modular and phenomenology driven. Examples of emerging phenomena of generic importance treated in this book are: -- The small world phenomenon in social and scale-free networks. -- Phase transitions and self-organized criticality in adaptive systems. -- Life at the edge of chaos and coevolutionary avalanches resulting from the unfolding of all living. -- The concept of living dynamical systems and emotional diffusive control within cognitive system theory. Techn...

Complex and adaptive dynamical systems a primer

CERN Document Server

Gros, Claudius

2007-01-01

We are living in an ever more complex world, an epoch where human actions can accordingly acquire far-reaching potentialities. Complex and adaptive dynamical systems are ubiquitous in the world surrounding us and require us to adapt to new realities and the way of dealing with them. This primer has been developed with the aim of conveying a wide range of "commons-sense" knowledge in the field of quantitative complex system science at an introductory level, providing an entry point to this both fascinating and vitally important subject. The approach is modular and phenomenology driven. Examples of emerging phenomena of generic importance treated in this book are: -- The small world phenomenon in social and scale-free networks. -- Phase transitions and self-organized criticality in adaptive systems. -- Life at the edge of chaos and coevolutionary avalanches resulting from the unfolding of all living. -- The concept of living dynamical systems and emotional diffusive control within cognitive system theory. Techn...

Adaptive feedforward in the LANL rf control system

International Nuclear Information System (INIS)

Ziomek, C.D.

1992-01-01

This paper describes an adaptive feedforward system that corrects repetitive errors in the amplitude and phase of the RF field of a pulsed accelerator. High-frequency disturbances that are beyond the effective bandwidth of the RF field feedback control system can be eliminated with a feedforward system. Many RF field disturbances for a pulsed accelerator are repetitive, occurring at the same relative time in every pulse. This design employs digital signal processing hardware to adaptively determine and track the control signals required to eliminate the repetitive errors in the feedback control system. In order to provide the necessary high-frequency response, the adaptive feedforward hardware provides the calculated control signal prior to the repetitive disturbance that it corrects. This system has been demonstrated to reduce the transient disturbances caused by beam pulses. Furthermore, it has been shown to negate high-frequency phase and amplitude oscillations in a high-power klystron amplifier caused by PFN ripple on the high-voltage. The design and results of the adaptive feedforward system are presented

Towards a Pattern Language for Adaptive Web-Based Educational Systems

NARCIS (Netherlands)

Avgeriou, P.; Vogiatzis, D.; Tzanavari, A.; Retalis, S.

2004-01-01

Adaptive Web-based Educational Systems represent an emerging technology that provides a unique advantage over traditional Web-based Educational Systems; that is the ability to adapt to the user's needs, goals, preferences etc. Adaptive Web-based Educational Systems are increasingly becoming part of

Design Patterns in Adaptive Web-Based Educational Systems : An Overview

NARCIS (Netherlands)

Avgeriou, Paris; Vogiatzis, Dimitrios; Tzanavari, Aimilia; Retalis, Symeon

2004-01-01

Adaptive Web-based Educational Systems represent an emerging technology that provides a unique advantage over traditional Web-based Educational Systems; that is the ability to adapt to the user's needs, goals, preferences etc. Adaptive Web-based Educational Systems are increasingly becoming part of

Certification Considerations for Adaptive Systems

Science.gov (United States)

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.

Adaptive pseudolinear compensators of dynamic characteristics of automatic control systems

Science.gov (United States)

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.

Adaptive Home System Using Wireless Sensor Network And Multi Agent System

OpenAIRE

Jayarani Kamble; Prof.Nandini Dhole

2014-01-01

Smart Home is an emerging technology growing continuously which includes number of new technologies which helps to improve human’s quality of living. This paper proposes an adaptive home system for optimum utilization of power, through Artificial Intelligence and Wireless Sensor network. Artificial Intelligence is a technology for developing adaptive system that can perceive the enviornmrnt, learn from the environment and can make decision using Rule based system.Zigbee is a w...

Changing Paradigms: From Schooling to Schools as Adaptive Recommendation Systems

Science.gov (United States)

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…

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

Science.gov (United States)

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...

Sinusoidal error perturbation reveals multiple coordinate systems for sensorymotor adaptation.

Science.gov (United States)

Hudson, Todd E; Landy, Michael S

2016-02-01

A coordinate system is composed of an encoding, defining the dimensions of the space, and an origin. We examine the coordinate encoding used to update motor plans during sensory-motor adaptation to center-out reaches. Adaptation is induced using a novel paradigm in which feedback of reach endpoints is perturbed following a sinewave pattern over trials; the perturbed dimensions of the feedback were the axes of a Cartesian coordinate system in one session and a polar coordinate system in another session. For center-out reaches to randomly chosen target locations, reach errors observed at one target will require different corrections at other targets within Cartesian- and polar-coded systems. The sinewave adaptation technique allowed us to simultaneously adapt both dimensions of each coordinate system (x-y, or reach gain and angle), and identify the contributions of each perturbed dimension by adapting each at a distinct temporal frequency. The efficiency of this technique further allowed us to employ perturbations that were a fraction the size normally used, which avoids confounding automatic adaptive processes with deliberate adjustments made in response to obvious experimental manipulations. Subjects independently corrected errors in each coordinate in both sessions, suggesting that the nervous system encodes both a Cartesian- and polar-coordinate-based internal representation for motor adaptation. The gains and phase lags of the adaptive responses are not readily explained by current theories of sensory-motor adaptation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Application of Complex Adaptive Systems in Portfolio Management

Science.gov (United States)

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.…

Adaptive Output Tracking Control for Nonlinear Systems with Failed Actuators and Aircraft Flight System Applications

OpenAIRE

Hou, Chuanjing; Hu, Lisheng; Zhang, Yingwei

2015-01-01

An adaptive failure compensation scheme using output feedback is proposed for a class of nonlinear systems with nonlinearities depending on the unmeasured states of systems. Adaptive high-gain K-filters are presented to suppress the nonlinearities while the proposed backstepping adaptive high-gain controller guarantees the stability of the closed-loop system and small tracking errors. Simulation results verify that the adaptive failure compensation scheme is effective.

Development of a geo-information system for the evaluation of active faults

Energy Technology Data Exchange (ETDEWEB)

Park, Dong Won; Pi, Nuen; Ger, Tien; Choi, Jun Hyoung [Paichai Univ., Daejeon (Korea, Republic of)

2003-02-15

In this work, we exploit hypermedia web database of geo-information system in order to access and share the multimedia data such as text,. graphics, animation, audio and video. It is gaining interest as a tool for effectively accessing the large amount of information that is available.

Development of a geo-information system for the evaluation of active faults

International Nuclear Information System (INIS)

Park, Dong Won; Pi, Nuen; Ger, Tien; Choi, Jun Hyoung

2003-02-01

In this work, we exploit hypermedia web database of geo-information system in order to access and share the multimedia data such as text,. graphics, animation, audio and video. It is gaining interest as a tool for effectively accessing the large amount of information that is available

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

Science.gov (United States)

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…

Adaptation in the auditory system: an overview

Directory of Open Access Journals (Sweden)

David ePérez-González

2014-02-01

Full Text Available The early stages of the auditory system need to preserve the timing information of sounds in order to extract the basic features of acoustic stimuli. At the same time, different processes of neuronal adaptation occur at several levels to further process the auditory information. For instance, auditory nerve fiber responses already experience adaptation of their firing rates, a type of response that can be found in many other auditory nuclei and may be useful for emphasizing the onset of the stimuli. However, it is at higher levels in the auditory hierarchy where more sophisticated types of neuronal processing take place. For example, stimulus-specific adaptation, where neurons show adaptation to frequent, repetitive stimuli, but maintain their responsiveness to stimuli with different physical characteristics, thus representing a distinct kind of processing that may play a role in change and deviance detection. In the auditory cortex, adaptation takes more elaborate forms, and contributes to the processing of complex sequences, auditory scene analysis and attention. Here we review the multiple types of adaptation that occur in the auditory system, which are part of the pool of resources that the neurons employ to process the auditory scene, and are critical to a proper understanding of the neuronal mechanisms that govern auditory perception.

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

Science.gov (United States)

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.

Adaptive Output Tracking Control for Nonlinear Systems with Failed Actuators and Aircraft Flight System Applications

Directory of Open Access Journals (Sweden)

Chuanjing Hou

2015-01-01

Full Text Available An adaptive failure compensation scheme using output feedback is proposed for a class of nonlinear systems with nonlinearities depending on the unmeasured states of systems. Adaptive high-gain K-filters are presented to suppress the nonlinearities while the proposed backstepping adaptive high-gain controller guarantees the stability of the closed-loop system and small tracking errors. Simulation results verify that the adaptive failure compensation scheme is effective.

Adaptive control of bifurcation and chaos in a time-delayed system

International Nuclear Information System (INIS)

Li Ning; Zhang Qing-Ling; Yuan Hui-Qun; Sun Hai-Yi

2013-01-01

In this paper, the stabilization of a continuous time-delayed system is considered. To control the bifurcation and chaos in a time-delayed system, a parameter perturbation control and a hybrid control are proposed. Then, to ensure the asymptotic stability of the system in the presence of unexpected system parameter changes, the adaptive control idea is introduced, i.e., the perturbation control parameter and the hybrid control parameter are automatically tuned according to the adaptation laws, respectively. The adaptation algorithms are constructed based on the Lyapunov-Krasovskii stability theorem. The adaptive parameter perturbation control and the adaptive hybrid control methods improve the corresponding constant control methods. They have the advantages of increased stability, adaptability to the changes of the system parameters, control cost saving, and simplicity. Numerical simulations for a well-known chaotic time-delayed system are performed to demonstrate the feasibility and superiority of the proposed control methods. A comparison of the two adaptive control methods is also made in an experimental study

Adaptive Synchronization of Memristor-based Chaotic Neural Systems

Directory of Open Access Journals (Sweden)

Xiaofang Hu

2014-11-01

Full Text Available Chaotic neural networks consisting of a great number of chaotic neurons are able to reproduce the rich dynamics observed in biological nervous systems. In recent years, the memristor has attracted much interest in the efficient implementation of artificial synapses and neurons. This work addresses adaptive synchronization of a class of memristor-based neural chaotic systems using a novel adaptive backstepping approach. A systematic design procedure is presented. Simulation results have demonstrated the effectiveness of the proposed adaptive synchronization method and its potential in practical application of memristive chaotic oscillators in secure communication.

A hydraulic hybrid propulsion method for automobiles with self-adaptive system

International Nuclear Information System (INIS)

Wu, Wei; Hu, Jibin; Yuan, Shihua; Di, Chongfeng

2016-01-01

A hydraulic hybrid vehicle with the self-adaptive system is proposed. The mode-switching between the driving mode and the hydraulic regenerative braking mode is realised by the pressure cross-feedback control. Extensive simulated and tested results are presented. The control parameters are reduced and the energy efficiency can be increased by the self-adaptive system. The mode-switching response is fast. The response time can be adjusted by changing the controlling spool diameter of the hydraulic operated check valve in the self-adaptive system. The closing of the valve becomes faster with a smaller controlling spool diameter. The hydraulic regenerative braking mode can be achieved by changing the hydraulic transformer controlled angle. Compared with the convention electric-hydraulic system, the self-adaptive system for the hydraulic hybrid vehicle mode-switching has a higher reliability and a lower cost. The efficiency of the hydraulic regenerative braking is also increased. - Highlights: • A new hybrid system with a self-adaptive system for automobiles is presented. • The mode-switching is realised by the pressure cross-feedback control. • The energy efficiency can be increased with the self-adaptive system. • The control parameters are reduced with the self-adaptive system.

Adaptive mechanism-based congestion control for networked systems

Science.gov (United States)

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.

Adaptive PI Controller for a Nonlinear System

Directory of Open Access Journals (Sweden)

D. Rathikarani

2009-10-01

Full Text Available Most of the industrial processes are inherently nonlinear in their behaviour. Designs of controllers for these nonlinear processes are difficult, as they do not follow superposition theorem. Adaptive controller can change its behaviour in response to changes in the dynamics of the process and disturbances. Hence adaptive controller can be used to control nonlinear processes. Direct Model Reference Adaptive Control is a technique, in which a reference model involving the desired performances is specified. In the present work, a DMRAC is designed and implemented to achieve satisfactory control of a nonlinear system in all its local linear operating regions. The closed loop system is made BIBO stable by proper control techniques. The controller is designed through simulation in Matlab platform and is validated in real time by conducting experiments on the laboratory Air Flow Control System using the dSPACE interface.

Application of stable adaptive schemes to nuclear reactor systems, (1)

International Nuclear Information System (INIS)

Fukuda, Toshio

1978-01-01

Parameter identification and adaptive control schemes are presented for a point reactor with internal feedbacks which lead to the nonlinearity of the overall system. Both are shown stable with new representation of the system, which corresponds to the nonminimal system representation, in the vein of the Model Reference Adaptive System (MRAS) via the Lyapunov's method. For the sake of the parameter identification, model parameters can be adjusted adaptively as soon as measurements start, while plant parameters can also adaptively be compensated through control input to reduce the output error between the model and the plant for the case of the adaptive control. In the case of the adaptive control, control schemes are presented for two cases, the case of the unknown decay constant of the delayed neutron and the case of the known constant. The adaptive control scheme for the latter case is shown extremely simpler than that for the former. Furthermore, when plant parameters vary slowly with time, computer simulations show that the proposed adaptive control scheme works satisfactorily enough to stabilize an unstable reactor and that it does even in the noise with small variance. (auth.)

Fundamentals of Adaptive Intelligent Tutoring Systems for Self-Regulated Learning

Science.gov (United States)

2015-03-01

ARL-SR-0318 ● MAR 2015 US Army Research Laboratory Fundamentals of Adaptive Intelligent Tutoring Systems for Self-Regulated...Adaptive Intelligent Tutoring Systems for Self-Regulated Learning by Robert A Sottilare Human Research and Engineering Directorate, ARL...TITLE AND SUBTITLE Fundamentals of Adaptive Intelligent Tutoring Systems for Self-Regulated Learning 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c

Adaptive, full-spectrum solar energy system

Science.gov (United States)

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.

Evaluation framework based on fuzzy measured method in adaptive learning systems

OpenAIRE

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

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. Adaptation methods are a basic factor to guaranty an effective adaptation. This issue is referred as meta-adaptation in numerous researches. In our research...

Novel Fuzzy-Modeling-Based Adaptive Synchronization of Nonlinear Dynamic Systems

Directory of Open Access Journals (Sweden)

Shih-Yu Li

2017-01-01

Full Text Available In this paper, a novel fuzzy-model-based adaptive synchronization scheme and its fuzzy update laws of parameters are proposed to address the adaptive synchronization problem. The proposed fuzzy controller does not share the same premise of fuzzy system, and the numbers of fuzzy controllers is reduced effectively through the novel modeling strategy. In addition, based on the adaptive synchronization scheme, the error dynamic system can be guaranteed to be asymptotically stable and the true values of unknown parameters can be obtained. Two identical complicated dynamic systems, Mathieu-Van der pol system (M-V system with uncertainties, are illustrated for numerical simulation example to show the effectiveness and feasibility of the proposed novel adaptive control strategy.

Adaptive process triage system cannot identify patients with gastrointestinal perforation

DEFF Research Database (Denmark)

Bohm, Aske Mathias; Tolstrup, Mai-Britt; Gögenur, Ismail

2017-01-01

INTRODUCTION: Adaptive process triage (ADAPT) is a triage tool developed to assess the severity and address the priority of emergency patients. In 2009-2011, ADAPT was the most frequently used triage system in Denmark. Until now, no Danish triage system has been evaluated based on a selective group...... triaged as green or yellow had a GIP that was not identified by the triage system. CONCLUSION: ADAPT is incapable of identifying one of the most critically ill patient groups in need of emergency abdominal surgery. FUNDING: none. TRIAL REGISTRATION: HEH-2013-034 I-Suite: 02336....

Adaptive self-correcting control system

International Nuclear Information System (INIS)

Ellis, S.H.

1984-01-01

A control system for regulating a controlled device or process, such as a turbofan engine, produces independent multiple estimates of one or more controlled variables of the device or process by combining the signals from a plurality of feedback sensors, which provide information related to the controlled variables, in weighted nonordered pairs. The independent multiple estimates of each controlled variable are combined into a weighted average, and individual estimates which differ by more than a specified amount from the weighted average are edited and temporarily removed from consideration. A revised weighted average value of each controlled variable is then produced, and this value is used to limit or control operation of the device or process. Adaptive trim is provided to compensate for changes in the device or process being controlled, such as engine deterioration, by slowly trimming each individual estimate toward the mean, and includes error compensation which constrains the weighted sum of the adaptive trims to equal zero, thereby preventing the adaptive trim from changing the operating level of the device or process. A secondary editing circuit based on a majority rule principle identifies a failed feedback sensor and permanently excludes all individual estimates of the controlled variable based on the failed sensor. Editing boundaries are increased and adaptive trim rate is varied when a transient occurs in the operation of the device or process. Further transient compensation may be required for a system with more severe transient requirements, and this invention includes compensation to selected feedback parameters such as turbine temperature to account for differences between steady state and transient values

Joint Adaptive Modulation and Combining for Hybrid FSO/RF Systems

KAUST Repository

Rakia, Tamer

2015-11-12

In this paper, we present and analyze a new transmission scheme for hybrid FSO/RF communication system based on joint adaptive modulation and adaptive combining. Specifically, the data rate on the FSO link is adjusted in discrete manner according to the FSO link\\'s instantaneous received signal-to-noise-ratio (SNR). If the FSO link\\'s quality is too poor to maintain the target bit-error-rate, the system activates the RF link along with the FSO link. When the RF link is activated, simultaneous transmission of the same modulated data takes place on both links, where the received signals from both links are combined using maximal ratio combining scheme. In this case, the data rate of the system is adjusted according to the instantaneous combined SNRs. Novel analytical expression for the cumulative distribution function (CDF) of the received SNR for the proposed adaptive hybrid system is obtained. This CDF expression is used to study the spectral and outage performances of the proposed adaptive hybrid FSO/RF system. Numerical examples are presented to compare the performance of the proposed adaptive hybrid FSO/RF system with that of switch-over hybrid FSO/RF and FSO-only systems employing the same adaptive modulation schemes. © 2015 IEEE.

Indirect adaptive control of discrete chaotic systems

International Nuclear Information System (INIS)

Salarieh, Hassan; Shahrokhi, Mohammad

2007-01-01

In this paper an indirect adaptive control algorithm is proposed to stabilize the fixed points of discrete chaotic systems. It is assumed that the functionality of the chaotic dynamics is known but the system parameters are unknown. This assumption is usually applicable to many chaotic systems, such as the Henon map, logistic and many other nonlinear maps. Using the recursive-least squares technique, the system parameters are identified and based on the feedback linearization method an adaptive controller is designed for stabilizing the fixed points, or unstable periodic orbits of the chaotic maps. The stability of the proposed scheme has been shown and the effectiveness of the control algorithm has been demonstrated through computer simulations

Adaptive, dynamic, and resilient systems

CERN Document Server

Suri, Niranjan

2015-01-01

As the complexity of today's networked computer systems grows, they become increasingly difficult to understand, predict, and control. Addressing these challenges requires new approaches to building these systems. Adaptive, Dynamic, and Resilient Systems supplies readers with various perspectives of the critical infrastructure that systems of networked computers rely on. It introduces the key issues, describes their interrelationships, and presents new research in support of these areas.The book presents the insights of a different group of international experts in each chapter. Reporting on r

Hypermedia presentation generation for semantic web information systems

NARCIS (Netherlands)

Frasincar, F.

2005-01-01

Due to Web popularity many information systems have been made available through the Web, resulting in so-called Web Information Systems (WIS). Due to the complex requirements that WIS need to ful??ll, the design of these systems is not a trivial task. Design methodologies provide guidelines for the

Simulated climate adaptation in storm-water systems: Evaluating the efficiency of within-system flexibility

Directory of Open Access Journals (Sweden)

Adam D. McCurdy

Full Text Available Changes in regional temperature and precipitation patterns resulting from global climate change may adversely affect the performance of long-lived infrastructure. Adaptation may be necessary to ensure that infrastructure offers consistent service and remains cost effective. But long service times and deep uncertainty associated with future climate projections make adaptation decisions especially challenging for managers. Incorporating flexibility into systems can increase their effectiveness across different climate futures but can also add significant costs. In this paper we review existing work on flexibility in climate change adaptation of infrastructure, such as robust decision-making and dynamic adaptive pathways, apply a basic typology of flexibility, and test alternative strategies for flexibility in distributed infrastructure systems comprised of multiple emplacements of a common, long-lived element: roadway culverts. Rather than treating a system of dispersed infrastructure elements as monolithic, we simulate “options flexibility” in which inherent differences in individual elements is incorporated into adaptation decisions. We use a virtual testbed of highway drainage crossing structures to examine the performance under different climate scenarios of policies that allow for multiple adaptation strategies with varying timing based on individual emplacement characteristics. Results indicate that a strategy with options flexibility informed by crossing characteristics offers a more efficient method of adaptation than do monolithic policies. In some cases this results in more cost-effective adaptation for agencies building long-lived, climate-sensitive infrastructure, even where detailed system data and analytical capacity is limited. Keywords: Climate adaptation, Stormwater management, Adaptation pathways

Adaptive feed forward in the LANL RF control system

International Nuclear Information System (INIS)

Ziomek, C.D.

1992-01-01

This paper describes an adaptive feed forward system that corrects repetitive errors in the amplitude and phase of the RF field of a pulsed accelerator. High-frequency disturbances that are beyond the effective bandwidth of the RF-field feedback control system can be eliminated with a feed forward system. Many RF-field disturbances for a pulsed accelerator are repetitive, occurring at the same relative time in every pulse. This design employs digital signal processing hardware to adaptively determine and track the control signals required to eliminate the repetitive errors in the feedback control system. In order to provide the necessary high-frequency response, the adaptive feed forward hardware provides the calculated control signal prior to the repetitive disturbance that it corrects. This system has been demonstrated to reduce the transient disturbances caused by beam pulses. Furthermore, it has been shown to negate high-frequency phase and amplitude oscillations in a high-power klystron amplifier caused by PFN ripple on the high-voltage. The design and results of the adaptive feed forward system are presented. (Author) 3 figs., 2 refs

Decentralized Adaptive Overcurrent Protection for Medium Voltage Maritime Power Systems

DEFF Research Database (Denmark)

Ciontea, Catalin-Iosif; Bak, Claus Leth; Blaabjerg, Frede

2016-01-01

the entire electrical network and changes the relay settings accordingly, but this approach is not adequate for the maritime power systems. This paper propose a decentralized adaptive protection method, where each protection relay is able to identify by itself the network status without the need of a central...... control unit. The new adaptive protection method is based on communication between the overcurrent relays and the equipment that could affect the protection system, such as circuit breakers and generators. Using PSCAD, the proposed method is implemented in a test medium voltage maritime power system......More and more maritime applications as marine vessels and offshore platforms need an adaptive protection power system. However, the adaptive protection is yet to be implemented in the maritime sector. Usually, the adaptive protection implies the existence of a central control unit that monitors...

Optimizing Input/Output Using Adaptive File System Policies

Science.gov (United States)

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.

Adaptive Non-linear Control of Hydraulic Actuator Systems

DEFF Research Database (Denmark)

Hansen, Poul Erik; Conrad, Finn

1998-01-01

Presentation of two new developed adaptive non-liner controllers for hydraulic actuator systems to give stable operation and improved performance.Results from the IMCIA project supported by the Danish Technical Research Council (STVF).......Presentation of two new developed adaptive non-liner controllers for hydraulic actuator systems to give stable operation and improved performance.Results from the IMCIA project supported by the Danish Technical Research Council (STVF)....

Outage Performance of Hybrid FSO/RF System with Low-Complexity Power Adaptation

KAUST Repository

Rakia, Tamer

2016-02-26

Hybrid free-space optical (FSO) / radio-frequency (RF) systems have emerged as a promising solution for high data- rate wireless communication systems. We consider truncated channel inversion based power adaptation strategy for coherent and non- coherent hybrid FSO/RF systems, employing an adaptive combining scheme. Specifically, we activate the RF link along with the FSO link when FSO link quality is unacceptable, and adaptively set RF transmission power to ensure constant combined signal-to-noise ratio at receiver terminal. Analytical expressions for the outage probability of the hybrid system with and without power adaptation are derived. Numerical examples show that, the hybrid FSO/RF systems with power adaptation achieve considerable outage performance improvement over conventional hybrid FSO/RF systems without power adaptation. © 2015 IEEE.

Development of fault tolerant adaptive control laws for aerospace systems

Science.gov (United States)

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.

Adaptive control of solar energy collector systems

CERN Document Server

Lemos, João M; Igreja, José M

2014-01-01

This book describes methods for adaptive control of distributed-collector solar fields: plants that collect solar energy and deliver it in thermal form. Controller design methods are presented that can overcome difficulties found in these type of plants:they are distributed-parameter systems, i.e., systems with dynamics that depend on space as well as time;their dynamics is nonlinear, with a bilinear structure;there is a significant level of uncertainty in plant knowledge.Adaptive methods form the focus of the text because of the degree of uncertainty in the knowledge of plant dynamics. Parts

CHIME : service-oriented framework for adaptive web-based systems

NARCIS (Netherlands)

Chepegin, V.; Aroyo, L.M.; De Bra, P.M.E.; Houben, G.J.P.M.; De Bra, P.M.E.

2003-01-01

In this paper we present our view on how the current development of knowledge engineering in the context of Semantic Web can contribute to the better applicability, reusability and sharability of adaptive web-based systems. We propose a service-oriented framework for adaptive web-based systems,

Integration of the immune system: a complex adaptive supersystem

Science.gov (United States)

Crisman, Mark V.

2001-10-01

Immunity to pathogenic organisms is a complex process involving interacting factors within the immune system including circulating cells, tissues and soluble chemical mediators. Both the efficiency and adaptive responses of the immune system in a dynamic, often hostile, environment are essential for maintaining our health and homeostasis. This paper will present a brief review of one of nature's most elegant, complex adaptive systems.

State of the Art: Personalization

DEFF Research Database (Denmark)

Durao, Frederico Araujo; Dolog, Peter; Jahn, Karsten

This is report surveys KIWI related work in the personalization domain. It discusses various approaches from adaptive hypermedia, user modelling, and semantic web which deal with personalization. It gives some suggestions on potential personalization strategies which can exploit knowledge...

Cuypers : a semi-automatic hypermedia generation system

NARCIS (Netherlands)

J.R. van Ossenbruggen (Jacco); F.J. Cornelissen; J.P.T.M. Geurts (Joost); L. Rutledge (Lloyd); L. Hardman (Lynda)

2000-01-01

textabstractThe report describes the architecture of emph{Cuypers, a system supporting second and third generation Web-based multimedia. First generation Web-content encodes information in handwritten (HTML) Web pages. Second generation Web content generates HTML pages on demand, e.g. by filling in

Development of adaptive control applied to chaotic systems

Science.gov (United States)

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.

Leadership Behaviors of Management for Complex Adaptive Systems

Science.gov (United States)

2010-04-01

Leadership Behaviors of Management for Complex Adaptive Systems Systems and Software Technology Conference April 2010 Dr. Suzette S. Johnson...2010 2. REPORT TYPE 3. DATES COVERED 00-00-2010 to 00-00-2010 4. TITLE AND SUBTITLE Leadership Behaviors of Management for Complex Adaptive...as they evolve – Control is dispersed and decentralized – Simple rules and governance used to direct behavior • Complexity Leadership Theory – Built on

Computational identification of adaptive mutants using the VERT system

Directory of Open Access Journals (Sweden)

Winkler James

2012-04-01

Full Text Available Background Evolutionary dynamics of microbial organisms can now be visualized using the Visualizing Evolution in Real Time (VERT system, in which several isogenic strains expressing different fluorescent proteins compete during adaptive evolution and are tracked using fluorescent cell sorting to construct a population history over time. Mutations conferring enhanced growth rates can be detected by observing changes in the fluorescent population proportions. Results Using data obtained from several VERT experiments, we construct a hidden Markov-derived model to detect these adaptive events in VERT experiments without external intervention beyond initial training. Analysis of annotated data revealed that the model achieves consensus with human annotation for 85-93% of the data points when detecting adaptive events. A method to determine the optimal time point to isolate adaptive mutants is also introduced. Conclusions The developed model offers a new way to monitor adaptive evolution experiments without the need for external intervention, thereby simplifying adaptive evolution efforts relying on population tracking. Future efforts to construct a fully automated system to isolate adaptive mutants may find the algorithm a useful tool.

HMM Adaptation for Improving a Human Activity Recognition System

Directory of Open Access Journals (Sweden)

Rubén San-Segundo

2016-09-01

Full Text Available When developing a fully automatic system for evaluating motor activities performed by a person, it is necessary to segment and recognize the different activities in order to focus the analysis. This process must be carried out by a Human Activity Recognition (HAR system. This paper proposes a user adaptation technique for improving a HAR system based on Hidden Markov Models (HMMs. This system segments and recognizes six different physical activities (walking, walking upstairs, walking downstairs, sitting, standing and lying down using inertial signals from a smartphone. The system is composed of a feature extractor for obtaining the most relevant characteristics from the inertial signals, a module for training the six HMMs (one per activity, and the last module for segmenting new activity sequences using these models. The user adaptation technique consists of a Maximum A Posteriori (MAP approach that adapts the activity HMMs to the user, using some activity examples from this specific user. The main results on a public dataset have reported a significant relative error rate reduction of more than 30%. In conclusion, adapting a HAR system to the user who is performing the physical activities provides significant improvement in the system’s performance.

Understanding sustainability from an exergetic frame in complex adaptive systems

International Nuclear Information System (INIS)

Aguilar Hernandez, Glem Alonso

2017-01-01

The concept of sustainability was developed from thermodynamic properties applied to complex adaptive systems. The origins of the perception about sustainable development and limitation in its application to analyze the interaction between a system and its surroundings were described. The properties of a complex adaptive system were taken as basis to determine how a system can to be affected by the resources restriction and irreversibility of the processes. The complex adaptive system was understood using the first and second law of thermodynamics, generating a conceptual framework to define the sustainability of a system. The contributions developed by exergy were shown to analyze the sustainability of systems in an economic, social and environmental context [es

All-Coefficient Adaptive Control of Dual-Motor Driving Servo System

Directory of Open Access Journals (Sweden)

Zhao Haibo

2017-01-01

Full Text Available Backlash nonlinearity and friction nonlinearity exist in dual-motor driving servo system, which reducing system response speed, steady accuracy and anti-interference ability. In order to diminish the adverse effects of backlash and friction nonlinearity to system, we proposed a new all-coefficient adaptive control method. Firstly, we introduced the dynamic model of backlash and friction nonlinearity respectively. Then on this basis, we established the characteristic model when backlash and friction nonlinearity coexist. We used recursive least square method for parameter estimation. Finally we designed the all-coefficient adaptive controller. On the basis of simplex all-coefficient adaptive controller, we designed a feedforward all-coefficient adaptive controller. The simulations of feedforward all-coefficient adaptive control and simplex all-coefficient adaptive control were compared. The results show that the former has quicker response speed, higher steady accuracy, stronger anti-interference performance and better robustness, which validating the efficacy of the proposed control strategy.

Promoting evaluation capacity building in a complex adaptive system.

Science.gov (United States)

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.

Towards Self-adaptation for Dependable Service-Oriented Systems

Science.gov (United States)

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.

Adaptive control of discrete-time chaotic systems: a fuzzy control approach

International Nuclear Information System (INIS)

Feng Gang; Chen Guanrong

2005-01-01

This paper discusses adaptive control of a class of discrete-time chaotic systems from a fuzzy control approach. Using the T-S model of discrete-time chaotic systems, an adaptive control algorithm is developed based on some conventional adaptive control techniques. The resulting adaptively controlled chaotic system is shown to be globally stable, and its robustness is discussed. A simulation example of the chaotic Henon map control is finally presented, to illustrate an application and the performance of the proposed control algorithm

Adaptive Integration of Nonsmooth Dynamical Systems

Science.gov (United States)

2017-10-11

2017 W911NF-12-R-0012-03: Adaptive Integration of Nonsmooth Dynamical Systems The views, opinions and/or findings contained in this report are those of...Integration of Nonsmooth Dynamical Systems Report Term: 0-Other Email: drum@gwu.edu Distribution Statement: 1-Approved for public release; distribution is...classdrake_1_1systems_1_1_integrator_base.html ; 3) a solver for dynamical systems with arbitrary unilateral and bilateral constraints (the key component of the time stepping systems )- see

The adaptive synchronization of fractional-order Liu chaotic system ...

Indian Academy of Sciences (India)

In this paper, the chaos control and the synchronization of two fractional-order Liu chaotic systems with unknown parameters are studied. According to the Lyapunov stabilization theory and the adaptive control theorem, the adaptive control rule is obtained for the described error dynamic stabilization. Using the adaptive rule ...

Fault-Tolerant Consensus of Multi-Agent System With Distributed Adaptive Protocol.

Science.gov (United States)

Chen, Shun; Ho, Daniel W C; Li, Lulu; Liu, Ming

2015-10-01

In this paper, fault-tolerant consensus in multi-agent system using distributed adaptive protocol is investigated. Firstly, distributed adaptive online updating strategies for some parameters are proposed based on local information of the network structure. Then, under the online updating parameters, a distributed adaptive protocol is developed to compensate the fault effects and the uncertainty effects in the leaderless multi-agent system. Based on the local state information of neighboring agents, a distributed updating protocol gain is developed which leads to a fully distributed continuous adaptive fault-tolerant consensus protocol design for the leaderless multi-agent system. Furthermore, a distributed fault-tolerant leader-follower consensus protocol for multi-agent system is constructed by the proposed adaptive method. Finally, a simulation example is given to illustrate the effectiveness of the theoretical analysis.

Contraction theory based adaptive synchronization of chaotic systems

International Nuclear Information System (INIS)

Sharma, B.B.; Kar, I.N.

2009-01-01

Contraction theory based stability analysis exploits the incremental behavior of trajectories of a system with respect to each other. Application of contraction theory provides an alternative way for stability analysis of nonlinear systems. This paper considers the design of a control law for synchronization of certain class of chaotic systems based on backstepping technique. The controller is selected so as to make the error dynamics between the two systems contracting. Synchronization problem with and without uncertainty in system parameters is discussed and necessary stability proofs are worked out using contraction theory. Suitable adaptation laws for unknown parameters are proposed based on the contraction principle. The numerical simulations verify the synchronization of the chaotic systems. Also parameter estimates converge to their true values with the proposed adaptation laws.

Adaptive Management of Communication in the Chamilo System of Distant Learning

OpenAIRE

Yatsenko Roman Nikolaevich; Polevich Olesya V.

2012-01-01

The article considers the communication management within an adaptive system of distance learning. We present two-circuit interaction system of the adaptive system. We consider the implementation of management communication in distance learning system based on the platform Chamilo.

Adaptive Federal Kalman Filtering for SINS/GPS Integrated System

Institute of Scientific and Technical Information of China (English)

杨勇; 缪玲娟

2003-01-01

A new adaptive federal Kalman filter for a strapdown integrated navigation system/global positioning system (SINS/GPS) is given. The developed federal Kalman filter is based on the trace operation of parameters estimation's error covariance matrix and the spectral radius of update measurement noise variance-covariance matrix for the proper choice of the filter weight and hence the filter gain factors. Theoretical analysis and results from simulation in which the SINS/GPS was compared to conventional Kalman filter are presented. Results show that the algorithm of this adaptive federal Kalman filter is simpler than that of the conventional one. Furthermore, it outperforms the conventional Kalman filter when the system is undertaken measurement malfunctions because of its possession of adaptive ability. This filter can be used in the vehicle integrated navigation system.

Computer aided systems human engineering: A hypermedia tool

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Adaptation of an Agile Information System Development Method

NARCIS (Netherlands)

Aydin, M.N.; Harmsen, A.F.; van Hillegersberg, Jos; Stegwee, R.A.; Siau, K.

2007-01-01

Little specific research has been conducted to date on the adaptation of agile information systems development (ISD) methods. This chapter presents the work practice in dealing with the adaptation of such a method in the ISD department of one of the leading financial institutes in Europe. The

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

Science.gov (United States)

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…

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

Energy Technology Data Exchange (ETDEWEB)

Colbaugh, Richard; Tsao, Jeffrey Yeenien; Johnson, Curtis Martin; Backus, George A.; Brown, Theresa Jean; Jones, Katherine A.

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 our 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

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

Science.gov (United States)

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.

Discrete Model Reference Adaptive Control System for Automatic Profiling Machine

Directory of Open Access Journals (Sweden)

Peng Song

2012-01-01

Full Text Available Automatic profiling machine is a movement system that has a high degree of parameter variation and high frequency of transient process, and it requires an accurate control in time. In this paper, the discrete model reference adaptive control system of automatic profiling machine is discussed. Firstly, the model of automatic profiling machine is presented according to the parameters of DC motor. Then the design of the discrete model reference adaptive control is proposed, and the control rules are proven. The results of simulation show that adaptive control system has favorable dynamic performances.

Adaptive control of chaotic continuous-time systems with delay

Science.gov (United States)

Tian, Yu-Chu; Gao, Furong

1998-06-01

A simple delay system governed by a first-order differential-delay equation may behave chaotically, but the conditions for the system to have such behaviors have not been well recognized. In this paper, a set of rules is postulated first for the conditions for the delay system to display chaos. A model-reference adaptive control scheme is then proposed to control the chaotic system state to converge to an arbitrarily given reference trajectory with certain and uncertain system parameters. Numerical examples are given to analyze the chaotic behaviors of the delay system and to demonstrate the effectiveness of the proposed adaptive control scheme.

Applications of decision theory to computer-based adaptive instructional systems

NARCIS (Netherlands)

Vos, Hendrik J.

1988-01-01

This paper considers applications of decision theory to the problem of instructional decision-making in computer-based adaptive instructional systems, using the Minnesota Adaptive Instructional System (MAIS) as an example. The first section indicates how the problem of selecting the appropriate

Adaptive Intrusion Data System (AIDS)

International Nuclear Information System (INIS)

Corlis, N.E.

1980-05-01

The adaptive intrusion data system (AIDS) was developed to collect data from intrusion alarm sensors as part of an evaluation system to improve sensor performance. AIDS is a unique data system which uses computer controlled data systems, video cameras and recorders, analog-to-digital conversion, environmental sensors, and digital recorders to collect sensor data. The data can be viewed either manually or with a special computerized data-reduction system which adds new data to a data base stored on a magnetic disc recorder. This report provides a synoptic account of the AIDS as it presently exists. Modifications to the purchased subsystems are described, and references are made to publications which describe the Sandia-designed subsystems

Application of stable adaptive schemes to nuclear reactor systems, (2)

International Nuclear Information System (INIS)

Kukuda, Toshio

1979-01-01

The parameter identification and adaptive control schemes applied in a previous study to a nonlinear point reactor are extended to the case of a loosely-coupled-core reactor with internal feedbacks, constituting a nonlinear overall system. Both schemes are shown to be stable, with the system newly represented on the pattern of the Model Reference Adaptive System (MRAS) with use made of the Lyapunov's method. For either parameter identification or adaptive control of a loosely-coupled-core reactor, there exists no canonical form of multiple input-multiple output system which can be directly applied for deriving the MRAS with the matrix version of the Kalman-Yakubovich lemma as it was in the case of the point reactor. This difficulty is circumvented by the practical assumption that the neutron density can be directly measured on each core as reactivity change is applied as input into the coupled core as a whole. For parameter identification, the model parameters are adaptively adjusted to those of each core, while for the adaptive control, plant parameters of each core can be adaptively compensated, again through control inputs, to asymptotically reduce the output error between the model and the plant. The point reactor is shown to correspond to a special case. (author)

Adaptive Dialogue Systems for Assistive Living Environments

Science.gov (United States)

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…

Adaptive networks as second order governance systems

NARCIS (Netherlands)

S.G. Nooteboom (Sibout); P.K. Marks (Peter)

2010-01-01

textabstractWe connect the idea of 'levers for change' with 'governance capacity' and propose 'adaptive networks' as an ideal type embedded in, and leveraging change in, governance systems. Discourses connect practices of citizens and companies with that governance system. Aware of

Indirect fuzzy adaptive control of a class of SISO nonlinear systems

International Nuclear Information System (INIS)

Laboid, S.; Boucherit, M.S.

2006-01-01

This paper presents an adaptive fuzzy control scheme for a class of continuous-time single-input single-output nonlinear systems with unknown dynamics and disturbance. Within this scheme, the fuzzy systems are employed to approximate the unknown system's dynamics. The proposed controller is composed of a well-defined adaptive fuzzy control term that uses the adaptive fuzzy approximation errors and disturbance. Based on a Lyapunov synthesis method, it is shown that the proposed adaptive control scheme guarantees the convergence of the tracking error to zero and the global boundedness of all signals in the closed-loop system. Moreover, the proposed controller allows initialization by zero of all adjusted parameters in the fuzzy approximators, and does not require the knowledge of the lower bound of the control gain and upper bounds of the approximation errors and disturbance. Simulation results performed on an inverted pendulum system are given to point out the good performance of the developed adaptive controller. (author)

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

Science.gov (United States)

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…

A Multi-Pathfinder for Developing Adaptive Robust Policies in System Dynamics

NARCIS (Netherlands)

Hamarat, C.; Pruyt, E.; Loonen, E.T.

2013-01-01

Adaptivity is essential for dynamically complex and uncertain systems. Adaptive policymaking is an approach to design policies that can be adapted over time to how the future unfolds. It is crucial for adaptive policymaking to specify under what conditions and how to adapt the policy. The

Cuypers : a semi-automatic hypermedia generation system

OpenAIRE

Ossenbruggen, Jacco; Cornelissen, F.J.; Geurts, Joost; Rutledge, Lloyd; Hardman, Lynda

2000-01-01

textabstractThe report describes the architecture of emph{Cuypers, a system supporting second and third generation Web-based multimedia. First generation Web-content encodes information in handwritten (HTML) Web pages. Second generation Web content generates HTML pages on demand, e.g. by filling in templates with content retrieved dynamically from a database or transformation of structured documents using style sheets (e.g. XSLT). Third generation Web pages will make use of rich markup (e.g. ...

Practical Approaches to Adaptive Resource Allocation in OFDM Systems

Directory of Open Access Journals (Sweden)

N. Y. Ermolova

2007-11-01

Full Text Available Whenever a communication system operates in a time-frequency dispersive radio channel, the link adaptation provides a benefit in terms of any system performance metric by employing time, frequency, and, in case of multiple users, multiuser diversities. With respect to an orthogonal frequency division multiplexing (OFDM system, link adaptation includes bit, power, and subcarrier allocations. While the well-known water-filling principle provides the optimal solution for both margin-maximization and rate-maximization problems, implementation complexity often makes difficult its application in practical systems. This paper presents a few suboptimal (low-complexity adaptive loading algorithms for both single- and multiuser OFDM systems. We show that the single-user system performance can be improved by suitable power loading and an algorithm based on the incomplete channel state information is derived. At the same time, the power loading in a multiuser system only slightly affects performance while the initial subcarrier allocation has a rather big impact. A number of subcarrier allocation algorithms are discussed and the best one is derived on the basis of the order statistics theory.

Adaptive projective synchronization of different chaotic systems with nonlinearity inputs

International Nuclear Information System (INIS)

Niu Yu-Jun; Pei Bing-Nan; Wang Xing-Yuan

2012-01-01

We investigate the projective synchronization of different chaotic systems with nonlinearity inputs. Based on the adaptive technique, sliding mode control method and pole assignment technique, a novel adaptive projective synchronization scheme is proposed to ensure the drive system and the response system with nonlinearity inputs can be rapidly synchronized up to the given scaling factor. (general)

Adaptation of a Data Acquisition System for Monitoring Air Quality and Radioactivity

International Nuclear Information System (INIS)

Ramadan, A.B.; Hefnawi, M.; Hefnaw, M.

2006-01-01

the main aim from this work is adapting the data acquisition system for monitoring air quality and radioactivity to save cost, time and effort. the adaptation processes are not only based on rectifying drawbacks but also modifying new features for both systems.these drawbacks are hardware problems and software problems for both systems which cause more operation cost, more operation time and more human effort these new features are modified to achieve the grown user requirements, better performance, more flexibility for customization and better user acceptance the adaptation method is implemented by determining: how exactly two systems work, components for each system and relationships between them, which components need adaptation, and finally suitable adaptation procedure for each component with maintaining the relationships between them the proposed systems overcome the above-mentioned drawbacks associated with the old systems and have new facilities to verify their main goals

Intelligent Adaptation Process for Case Based Systems

International Nuclear Information System (INIS)

Nassar, A.M.; Mohamed, A.H.; Mohamed, A.H.

2014-01-01

Case Based Reasoning (CBR) Systems is one of the important decision making systems applied in many fields all over the world. The effectiveness of any CBR system based on the quality of the storage cases in the case library. Similar cases can be retrieved and adapted to produce the solution for the new problem. One of the main issues faced the CBR systems is the difficulties of achieving the useful cases. The proposed system introduces a new approach that uses the genetic algorithm (GA) technique to automate constructing the cases into the case library. Also, it can optimize the best one to be stored in the library for the future uses. However, the proposed system can avoid the problems of the uncertain and noisy cases. Besides, it can simply the retrieving and adaptation processes. So, it can improve the performance of the CBR system. The suggested system can be applied for many real-time problems. It has been applied for diagnosis the faults of the wireless network, diagnosis of the cancer diseases, diagnosis of the debugging of a software as cases of study. The proposed system has proved its performance in this field

Adaptation in the innate immune system and heterologous innate immunity.

Science.gov (United States)

Martin, Stefan F

2014-11-01

The innate immune system recognizes deviation from homeostasis caused by infectious or non-infectious assaults. The threshold for its activation seems to be established by a calibration process that includes sensing of microbial molecular patterns from commensal bacteria and of endogenous signals. It is becoming increasingly clear that adaptive features, a hallmark of the adaptive immune system, can also be identified in the innate immune system. Such adaptations can result in the manifestation of a primed state of immune and tissue cells with a decreased activation threshold. This keeps the system poised to react quickly. Moreover, the fact that the innate immune system recognizes a wide variety of danger signals via pattern recognition receptors that often activate the same signaling pathways allows for heterologous innate immune stimulation. This implies that, for example, the innate immune response to an infection can be modified by co-infections or other innate stimuli. This "design feature" of the innate immune system has many implications for our understanding of individual susceptibility to diseases or responsiveness to therapies and vaccinations. In this article, adaptive features of the innate immune system as well as heterologous innate immunity and their implications are discussed.

HyperPeer

DEFF Research Database (Denmark)

Larsen, R.D.; Bouvin, N.O.

2004-01-01

This paper presents HyperPeer, a framework for developing peer-to-peer based hypermedia. The distribution of hypermedia structures is handled through a peer-to-peer (P2P) network, allowing for highly scalable sharing between users. A central challenge of all decentralized systems is to locate...

USING THE ADAPTED DLP SYSTEM FOR BLOCKING INFORMATION LEAKS

Directory of Open Access Journals (Sweden)

T. A. Andryianava

2017-01-01

Full Text Available The importance of using the adapted DLP-system in the «Blocking» mode of leaking confidential information of the company is investigated. The scheme of interception of information security events in the «Copy» mode is given, the analysis of which reflects the main drawback of using this mode – the DLP-system works only with copies of confidential documents, while the originals were delivered to the recipient. Such cases inflict enormous damage on companies, so the transfer of critical information beyond the corporate network is unacceptable.A solution is proposed for transferring the operation of the DLP-system from the «Copy» mode to the «Blocking» mode. It is important that the operation of the DLP-system does not hinder the staff members from performing regular operations and does not hinder business processes. Therefore, it is mandatory to adapt the standard DLP-system to the specifics of the company’s activities. After that the transition of the adapted DLP-system to the «Blocking» mode is carried out.Developed: the transition procedure of the adapted DLP-system from the «Copy» mode to the «Blocking» mode, the scheme of the event capture by the DLP-system for the two modes. The main channels of data leaks were investigated, the main leaks were identified by the data type and by the transmission channel. The analysis of the DLP-system operation in the «Blocking» mode is performed.

Izvođenje umetničko/teorijskog rada u mediju hiperteksta – net art Marka Amerike / Performance of Artistic/Theoretical Work in Medium of Hypertext – Mark Amerika’s Net Art

Directory of Open Access Journals (Sweden)

Sanela Nikolić

2014-10-01

Full Text Available In this study, I focus on the problem of relations between art and theoretical work when they are performed in hypertext/hypermedia Net Art environment. Mark Amerika’s hypermedia practice, produced by digital technologies and focused on the questions of status, functions and modes of art and theory productions in information and biopolitical society, is considered as a case study. Amerika uses hypertext and hypermedia for realization of research art practice and as a media of post-pedagogical and theoretical work which deviate from determined types of scholarly discourses about art and expanding the concept of writing in hypermedia direction. Referring to biopolitical theories, Amerika emphasizes the communication linkage problem between biological organism and networked, hypertextual systems which is always de/regulatory. Remixology, implemented in digital, interactive internet environment, Amerika considers as a critical metaactivity against the manipulation of behavior in mass media of communications space and system of global networking.

CRISPR-Cas adaptive immune systems of the sulfolobales

DEFF Research Database (Denmark)

Garrett, Roger Antony; Shah, Shiraz Ali; Erdmann, Susanne

2015-01-01

The Sulfolobales have provided good model organisms for studying CRISPR-Cas systems of the crenarchaeal kingdom of the archaea. These organisms are infected by a wide range of exceptional archaea-specific viruses and conjugative plasmids, and their CRISPR-Cas systems generally exhibit extensive...... structural and functional diversity. They carry large and multiple CRISPR loci and often multiple copies of diverse Type I and Type III interference modules as well as more homogeneous adaptation modules. These acidothermophilic organisms have recently provided seminal insights into both the adaptation...... process, the diverse modes of interference, and their modes of regulation. The functions of the adaptation and interference modules tend to be loosely coupled and the stringency of the crRNA-DNA sequence matching during DNA interference is relatively low, in contrast to some more streamlined CRISPR...

Engineering the presentation layer of adaptable web information systems

NARCIS (Netherlands)

Fiala, Z.; Frasincar, F.; Hinz, M.; Houben, G.J.P.M.; Barna, P.; Meissner, K.; Koch, N.; Fraternali, P.; Wirsing, M.

2004-01-01

Engineering adaptable Web Information Systems (WIS) requires systematic design models and specification frameworks. A complete model-driven methodology like Hera distinguishes between the conceptual, navigational, and presentational aspects of WIS design and identifies different adaptation hot-spots

Cross-bandwidth adaptation for ASR systems

CSIR Research Space (South Africa)

Kleynhans, N

2013-12-01

Full Text Available not be feasible for resource-scarce environments. Utilising limited amounts of in-domain data and a combination of feature normalisation and acoustic model adaptation techniques has therefore found wide use in ASR systems. Various approaches have been proposed...

Adaptive Integral Sliding Mode Stabilization of Nonholonomic Drift-Free Systems

Directory of Open Access Journals (Sweden)

Waseem Abbasi

2016-01-01

Full Text Available This article presents adaptive integral sliding mode control algorithm for the stabilization of nonholonomic drift-free systems. First the system is transformed, by using input transform, into a special structure containing a nominal part and some unknown terms which are computed adaptively. The transformed system is then stabilized using adaptive integral sliding mode control. The stabilizing controller for the transformed system is constructed that consists of the nominal control plus a compensator control. The compensator control and the adaptive laws are derived on the basis of Lyapunov stability theory. The proposed control algorithm is applied to three different nonholonomic drift-free systems: the unicycle model, the front wheel car model, and the mobile robot with trailer model. The controllability Lie algebra of the unicycle model contains Lie brackets of depth one, the model of a front wheel car contains Lie brackets of depths one and two, and the model of a mobile robot with trailer contains Lie brackets of depths one, two, and three. The effectiveness of the proposed control algorithm is verified through numerical simulations.

Duration Adaptation Occurs Across the Sub- and Supra-Second Systems.

Science.gov (United States)

Shima, Shuhei; Murai, Yuki; Hashimoto, Yuki; Yotsumoto, Yuko

2016-01-01

After repetitive exposure to a stimulus of relatively short duration, a subsequent stimulus of long duration is perceived as being even longer, and after repetitive exposure to a stimulus of relatively long duration, a subsequent stimulus of short duration is perceived as being even shorter. This phenomenon is called duration adaptation, and has been reported only for sub-second durations. We examined whether duration adaptation also occurs for supra-second durations (Experiment 1) and whether duration adaptation occurs across sub- and supra-second durations (Experiment 2). Duration adaptation occurred not only for sub-second durations, but also for supra-second durations and across sub- and supra-second durations. These results suggest that duration adaptation involves an interval-independent system or two functionally related systems that are associated with both the sub- and supra-second durations.

Integrated Damage-Adaptive Control System (IDACS), Phase I

Data.gov (United States)

National Aeronautics and Space Administration — SSCI, in collaboration with Boeing Phantom Works, proposes to develop and test an efficient Integrated Damage Adaptive Control System (IDACS). The proposed system is...

Real-Time Measurements for Adaptive and Cognitive Radio Systems

Directory of Open Access Journals (Sweden)

Hüseyin Arslan

2009-01-01

Full Text Available Adaptive and cognitive radios (CR have been becoming popular for optimizing mobile radio system transmission and reception. One of the most important elements of the adaptive radio and CR concepts is the ability to measure, sense, learn about, and be aware of parameters related to the radio channel characteristics, availability of spectrum and power, interference and noise temperature, operational environment of radio, user requirements and applications, available networks and infrastructures, local policies, other operating restrictions, and so on. This paper discusses some of the important measurement parameters for enabling adaptive radio and CR systems along with their relationships and impacts on the performance including relevant challenges.

Multi Agent System Based Adaptive Protection for Dispersed Generation Integrated Distribution Systems

DEFF Research Database (Denmark)

Liu, Leo; Rather, Zakir Hussain; Bak, Claus Leth

2013-01-01

The increasing penetration of dispersed generation (DG) brings challenges to conventional protection approaches of distribution system, mainly due to bi-directional power flow and variable fault current contribution from different generation technology-based DG units. Moreover, the trend......) is proposed. The adaptive protection intelligently adopts suitable settings for the variation of fault current from diversified DG units. Furthermore, the structure of mobile MAS with additional flexibility is capable of adapting the changes of system topology in a short period, e.g. radial/meshed, grid...

Control uncertain Genesio-Tesi chaotic system: Adaptive sliding mode approach

International Nuclear Information System (INIS)

Dadras, Sara; Momeni, Hamid Reza

2009-01-01

An adaptive sliding mode control (ASMC) technique is introduced in this paper for a chaotic dynamical system (Genesio-Tesi system). Using the sliding mode control technique, a sliding surface is determined and the control law is established. An adaptive sliding mode control law is derived to make the states of the Genesio-Tesi system asymptotically track and regulate the desired state. The designed control scheme can control the uncertain chaotic behaviors to a desired state without oscillating very fast and guarantee the property of asymptotical stability. An illustrative simulation result is given to demonstrate the effectiveness of the proposed adaptive sliding mode control design.

Adapted breeds for organic and low input dairy systems

DEFF Research Database (Denmark)

Horn, Marco; Ferris, C; Sairanen, A

2014-01-01

Part of SOLID is to understand how contrasting genotypes adapt to a systematic restriction of nutrient and energy supply. In new studies, a number of genotypes identified as being adapted to organic and low input systems were compared with conventional breeds....

Adaptive management of social-ecological systems: the path forward

Science.gov (United States)

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.

Adaptive modified function projective synchronization of multiple time-delayed chaotic Rossler system

International Nuclear Information System (INIS)

Sudheer, K. Sebastian; Sabir, M.

2011-01-01

In this Letter we consider modified function projective synchronization of unidirectionally coupled multiple time-delayed Rossler chaotic systems using adaptive controls. Recently, delay differential equations have attracted much attention in the field of nonlinear dynamics. The high complexity of the multiple time-delayed systems can provide a new architecture for enhancing message security in chaos based encryption systems. Adaptive control can be used for synchronization when the parameters of the system are unknown. Based on Lyapunov stability theory, the adaptive control law and the parameter update law are derived to make the state of two chaotic systems are function projective synchronized. Numerical simulations are presented to demonstrate the effectiveness of the proposed adaptive controllers.

Substantiation of Structure of Adaptive Control Systems for Motor Units

Science.gov (United States)

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.

Identification of chaotic memristor systems based on piecewise adaptive Legendre filters

International Nuclear Information System (INIS)

Zhao, Yibo; Zhang, Xiuzai; Xu, Jin; Guo, Yecai

2015-01-01

Memristor is a nonlinear device, which plays an important role in the design and implementation of chaotic systems. In order to be able to understand in-depth the complex nonlinear dynamic behaviors in chaotic memristor systems, modeling or identification of its nonlinear model is very important premise. This paper presents a chaotic memristor system identification method based on piecewise adaptive Legendre filters. The threshold decomposition is carried out for the input vector, and also the input signal subintervals via decomposition satisfy the convergence condition of the adaptive Legendre filters. Then the adaptive Legendre filter structure and adaptive weight update algorithm are derived. Final computer simulation results show the effectiveness as well as fast convergence characteristics.

Climate change adaptability of cropping and farming systems for Europe

DEFF Research Database (Denmark)

Justes, Eric; Rossing, Walter; Vermue, Anthony

systems to CC through a gradient of adaptation strategies. Methods: The adaptation strategies are evaluated at cropping and farming systems as well as regional levels for nine “Adaptation Pilots” along a North-South climate gradient in the EU. Three categories of strategies are evaluated: i) Resistance...... and foster learning in participatory co-design workshops. Results and expectations: The expected results of the Climate-CAFE on-going project will produce an overview of potential CC adaptation measures for selected sites across the EU, along with mutual learning experiences for improved understanding......Introduction: Prospective studies showed that the European agriculture will be impacted by climate change (CC) with different effects depending on the geographic region. The ERA-Net+ project Climate-CAFE (call of FACCE-JPI) aims to improve the “adaptive capacity” of arable and forage based farming...

Two Perspectives on Information System Adaptation

DEFF Research Database (Denmark)

Jensen, Tina Blegind; Kjærgaard, Annemette; Svejvig, Per

Institutional theory has proven to be a central analytical perspective for investigating the role of larger social and historical structures of Information System (IS) adaptation. However, it does not explicitly account for how organizational actors make sense of and enact IS in their local context...

Adaptive Optical System for Retina Imaging Approaches Clinic Applications

Science.gov (United States)

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.

Adaptive fuzzy bilinear observer based synchronization design for generalized Lorenz system

International Nuclear Information System (INIS)

Baek, Jaeho; Lee, Heejin; Kim, Seungwoo; Park, Mignon

2009-01-01

This Letter proposes an adaptive fuzzy bilinear observer (FBO) based synchronization design for generalized Lorenz system (GLS). The GLS can be described to TS fuzzy bilinear generalized Lorenz model (FBGLM) with their states immeasurable and their parameters unknown. We design an adaptive FBO based on TS FBGLM for synchronization. Lyapunov theory is employed to guarantee the stability of error dynamic system via linear matrix equalities (LMIs) and to derive the adaptive laws to estimate unknown parameters. Numerical example is given to demonstrate the validity of our proposed adaptive FBO approach for synchronization.

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

International Nuclear Information System (INIS)

Salmon, J.T.; Bliss, E.S.; Byrd, J.L.; Feldman, M.; Kartz, M.A.; Toeppen, J.S.; Wonterghem, B. Van; Winters, S.E.

1995-01-01

Using adaptive optics the authors have obtained nearly diffraction-limited 5 kJ, 3 nsec output pulses at 1.053 microm 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 microm 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 correct 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

Cognitive Psychology and Design Paradigms in the Development of Multimedia Courseware

Science.gov (United States)

1993-09-01

FrameMaker ................................... 49 vi VI. CONCLUSIONS AND RECOMMENDATIONS .................. 51 A. CONCLUSIONS...Microsystems, Inc., 1990), FrameMaker (Frame Technology Corp., 1990) and the MAEstro authoring system (Drapeau & Greenfield, 1992), we began the development...interactive hypermedia document development. FrameMaker was used to simulate an interactive hypermedia environment. E. ORGANIZATION OF PAPER Chapter

Robust synchronization of drive-response chaotic systems via adaptive sliding mode control

International Nuclear Information System (INIS)

Li, W.-L.; Chang, K.-M.

2009-01-01

A robust adaptive sliding control scheme is developed in this study to achieve synchronization for two identical chaotic systems in the presence of uncertain system parameters, external disturbances and nonlinear control inputs. An adaptation algorithm is given based on the Lyapunov stability theory. Using this adaptation technique to estimate the upper-bounds of parameter variation and external disturbance uncertainties, an adaptive sliding mode controller is then constructed without requiring the bounds of parameter and disturbance uncertainties to be known in advance. It is proven that the proposed adaptive sliding mode controller can maintain the existence of sliding mode in finite time in uncertain chaotic systems. Finally, numerical simulations are presented to show the effectiveness of the proposed control scheme.

Adaptive optics system application for solar telescope

Science.gov (United States)

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.

Next generation intelligent environments ambient adaptive systems

CERN Document Server

Nothdurft, Florian; Heinroth, Tobias; Minker, Wolfgang

2016-01-01

This book covers key topics in the field of intelligent ambient adaptive systems. It focuses on the results worked out within the framework of the ATRACO (Adaptive and TRusted Ambient eCOlogies) project. The theoretical background, the developed prototypes, and the evaluated results form a fertile ground useful for the broad intelligent environments scientific community as well as for industrial interest groups. The new edition provides: Chapter authors comment on their work on ATRACO with final remarks as viewed in retrospective Each chapter has been updated with follow-up work emerging from ATRACO An extensive introduction to state-of-the-art statistical dialog management for intelligent environments Approaches are introduced on how Trust is reflected during the dialog with the system.

Adaptive Control of the Chaotic System via Singular System Approach

Directory of Open Access Journals (Sweden)

Yudong Li

2014-01-01

Full Text Available This paper deals with the control problem of the chaotic system subject to disturbance. The sliding mode surface is designed by singular system approach, and sufficient condition for convergence is given. Then, the adaptive sliding mode controller is designed to make the state arrive at the sliding mode surface in finite time. Finally, Lorenz system is considered as an example to show the effectiveness of the proposed method.

Semantic models for adaptive interactive systems

CERN Document Server

Hussein, Tim; Lukosch, Stephan; Ziegler, Jürgen; Calvary, Gaëlle

2013-01-01

Providing insights into methodologies for designing adaptive systems based on semantic data, and introducing semantic models that can be used for building interactive systems, this book showcases many of the applications made possible by the use of semantic models.Ontologies may enhance the functional coverage of an interactive system as well as its visualization and interaction capabilities in various ways. Semantic models can also contribute to bridging gaps; for example, between user models, context-aware interfaces, and model-driven UI generation. There is considerable potential for using

Modeling Adaptive Behavior for Systems Design

DEFF Research Database (Denmark)

Rasmussen, Jens

1994-01-01

Field studies in modern work systems and analysis of recent major accidents have pointed to a need for better models of the adaptive behavior of individuals and organizations operating in a dynamic and highly competitive environment. The paper presents a discussion of some key characteristics.......) The basic difference between the models of system functions used in engineering and design and those evolving from basic research within the various academic disciplines and finally 3.) The models and methods required for closed-loop, feedback system design....

Towards Contextualized Learning Services

Science.gov (United States)

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.

Modeling Power Systems as Complex Adaptive Systems

Energy Technology Data Exchange (ETDEWEB)

Chassin, David P.; Malard, Joel M.; Posse, Christian; Gangopadhyaya, Asim; Lu, Ning; Katipamula, Srinivas; Mallow, J V.

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 review 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.

A Comment on Language Is a Complex Adaptive System:Position Paper

Institute of Scientific and Technical Information of China (English)

单妍

2014-01-01

Language not only functions as a communication tool, it has fundamental functions. People ’s social interaction and their past experience can affect people’s choice of language, as language is a complex, adaptive system. The paper tries to com-ment on“A comment on Language Is a Complex Adaptive System: Position Paper”from several aspects to conclude that Lan-guage Is a Complex Adaptive System:Position Paper is a comprehensive, creative and influential academic paper which is charac-teristic of high originality, well-compact organization, detailed literature review.

Adaptive Modeling of the International Space Station Electrical Power System

Science.gov (United States)

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.

Design of uav robust autopilot based on adaptive neuro-fuzzy inference system

Directory of Open Access Journals (Sweden)

Mohand Achour Touat

2008-04-01

Full Text Available  This paper is devoted to the application of adaptive neuro-fuzzy inference systems to the robust control of the UAV longitudinal motion. The adaptive neore-fuzzy inference system model needs to be trained by input/output data. This data were obtained from the modeling of a ”crisp” robust control system. The synthesis of this system is based on the separation theorem, which defines the structure and parameters of LQG-optimal controller, and further - robust optimization of this controller, based on the genetic algorithm. Such design procedure can define the rule base and parameters of fuzzyfication and defuzzyfication algorithms of the adaptive neore-fuzzy inference system controller, which ensure the robust properties of the control system. Simulation of the closed loop control system of UAV longitudinal motion with adaptive neore-fuzzy inference system controller demonstrates high efficiency of proposed design procedure.

Fuzzy model-based adaptive synchronization of time-delayed chaotic systems

International Nuclear Information System (INIS)

Vasegh, Nastaran; Majd, Vahid Johari

2009-01-01

In this paper, fuzzy model-based synchronization of a class of first order chaotic systems described by delayed-differential equations is addressed. To design the fuzzy controller, the chaotic system is modeled by Takagi-Sugeno fuzzy system considering the properties of the nonlinear part of the system. Assuming that the parameters of the chaotic system are unknown, an adaptive law is derived to estimate these unknown parameters, and the stability of error dynamics is guaranteed by Lyapunov theory. Numerical examples are given to demonstrate the validity of the proposed adaptive synchronization approach.

Complex adaptive systems ecology

DEFF Research Database (Denmark)

Sommerlund, Julie

2003-01-01

In the following, I will analyze two articles called Complex Adaptive Systems EcologyI & II (Molin & Molin, 1997 & 2000). The CASE-articles are some of the more quirkyarticles that have come out of the Molecular Microbial Ecology Group - a groupwhere I am currently making observational studies....... They are the result of acooperation between Søren Molin, professor in the group, and his brother, JanMolin, professor at Department of Organization and Industrial Sociology atCopenhagen Business School. The cooperation arises from the recognition that bothmicrobial ecology and sociology/organization theory works...

Adaptive integral robust control and application to electromechanical servo systems.

Science.gov (United States)

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.

Power adaptation for joint switched diversity and adaptive modulation schemes in spectrum sharing systems

KAUST Repository

Bouida, Zied

2012-09-01

Under the scenario of an underlay cognitive radio network, we propose in this paper an adaptive scheme using transmit power adaptation, switched transmit diversity, and adaptive modulation in order to improve the performance of existing switching efficient schemes (SES) and bandwidth efficient schemes (BES). Taking advantage of the channel reciprocity principle, we assume that the channel state information (CSI) of the interference link is available to the secondary transmitter. This information is then used by the secondary transmitter to adapt its transmit power, modulation constellation size, and used transmit branch. The goal of this joint adaptation is to minimize the average number of switched branches and the average system delay given the fading channel conditions, the required error rate performance, and a peak interference constraint to the primary receiver. We analyze the proposed scheme in terms of the average number of branch switching, average delay, and we provide a closed-form expression of the average bit error rate (BER). We demonstrate through numerical examples that the proposed scheme provides a compromise between the SES and the BES schemes. © 2012 IEEE.

Power adaptation for joint switched diversity and adaptive modulation schemes in spectrum sharing systems

KAUST Repository

Bouida, Zied; Tourki, Kamel; Ghrayeb, Ali A.; Qaraqe, Khalid A.; Alouini, Mohamed-Slim

2012-01-01

Under the scenario of an underlay cognitive radio network, we propose in this paper an adaptive scheme using transmit power adaptation, switched transmit diversity, and adaptive modulation in order to improve the performance of existing switching efficient schemes (SES) and bandwidth efficient schemes (BES). Taking advantage of the channel reciprocity principle, we assume that the channel state information (CSI) of the interference link is available to the secondary transmitter. This information is then used by the secondary transmitter to adapt its transmit power, modulation constellation size, and used transmit branch. The goal of this joint adaptation is to minimize the average number of switched branches and the average system delay given the fading channel conditions, the required error rate performance, and a peak interference constraint to the primary receiver. We analyze the proposed scheme in terms of the average number of branch switching, average delay, and we provide a closed-form expression of the average bit error rate (BER). We demonstrate through numerical examples that the proposed scheme provides a compromise between the SES and the BES schemes. © 2012 IEEE.

Evaluation Framework Based on Fuzzy Measured Method in Adaptive Learning Systems

Science.gov (United States)

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.…

Analytic Model Predictive Control of Uncertain Nonlinear Systems: A Fuzzy Adaptive Approach

Directory of Open Access Journals (Sweden)

Xiuyan Peng

2015-01-01

Full Text Available A fuzzy adaptive analytic model predictive control method is proposed in this paper for a class of uncertain nonlinear systems. Specifically, invoking the standard results from the Moore-Penrose inverse of matrix, the unmatched problem which exists commonly in input and output dimensions of systems is firstly solved. Then, recurring to analytic model predictive control law, combined with fuzzy adaptive approach, the fuzzy adaptive predictive controller synthesis for the underlying systems is developed. To further reduce the impact of fuzzy approximation error on the system and improve the robustness of the system, the robust compensation term is introduced. It is shown that by applying the fuzzy adaptive analytic model predictive controller the rudder roll stabilization system is ultimately uniformly bounded stabilized in the H-infinity sense. Finally, simulation results demonstrate the effectiveness of the proposed method.

An Adapted Wayfinding System for Pedestrians with Cognitive Disabilities

Directory of Open Access Journals (Sweden)

Javier Gomez

2015-01-01

Full Text Available This paper presents a novel wayfinding system adapted to people with cognitive disabilities. It adapts to the user in terms of route calculation, instructions delivery, and interface design. To do so, the system divides the calculated route into atomic instructions and uses street-level photographs at the decision points. To evaluate this approach, we compared it with a commercial navigation application on a field trial with a sample of users (N = 18. From the evaluation, we concluded that our system improves users’ performance in terms of the number who reached the destination and were able to identify it correctly.

Homeostatic regulation of memory systems and adaptive decisions.

Science.gov (United States)

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

Adaptive vibration isolation system for diesel engine

Institute of Scientific and Technical Information of China (English)

YANG Tie-jun; ZHANG Xin-yu; XIAO You-hong; HUANG Jin-e; LIU Zhi-gang

2004-01-01

An active two-stage isolation mounting, on which servo-hydraulic system is used as the actuator (secondary vibration source) and a diesel engine is used as primary vibration source, has been built. The upper mass of the mounting is composed of a 495diesel and an electrical eddy current dynamometer. The lower mass is divided into four small masses to which servo-hydraulic actuator and rubber isolators are attached. According to the periodical characteristics of diesel vibration signals, a multi-point adaptive strategy based on adaptive comb filtered algorithm is applied to active multi-direction coupled vibrations control for the engine. The experimental results demonstrate that a good suppression in the effective range of phase compensation in secondary path (within 100Hz) at different operation conditions is achieved, and verify that this strategy is effective. The features of the active system, the development activities carried out on the system and experimental results are discussed in the paper.

Problems of Aero-optics and Adaptive Optical Systems: Analytical Review

Directory of Open Access Journals (Sweden)

Yu. I. Shanin

2017-01-01

Full Text Available The analytical review gives the basic concepts of the aero-optics problem arising from the radiation propagation in the region of the boundary layers of a laser installation carrier aircraft. Estimates the radiation wave front distortions at its propagation in the near and far field. Presents main calculation approaches and methods to solve the gas-dynamic and optical problems in propagating laser radiation. Conducts a detailed analysis of the flows and their generating optical aberrations introduced by the aircraft turret (a projection platform of the on-board laser. Considers the effect of various factors (shock wave, difference in wall and flow temperatures on the flow pattern and the optical aberrations. Provides research data on the aero-optics obtained in the flying laboratory directly while in flight. Briefly considers the experimental research methods, diagnostic equipment, and synthesis of results while studying the aero-optics problem. Discusses some methods for mitigating the aerodynamic effects on the light propagation under flight conditions. Presents data about the passive, active, and hybrid effects on the flow in the boundary layers in order to reduce aberrations through improving the flow aerodynamics.The paper considers operation of adaptive optical systems under conditions of aero-optical distortions. Presents the study results concerning the reduction of the aero-optics effect on the characteristics of radiation in far field. Gives some research results regarding the effect on the efficiency of the adaptive system of a laser beam jitter and a time delay in the feedback signal transmission, which occur under application conditions. Provides data on adaptive correction of aero-optical wave fronts of radiation. Considers some application aspects in control systems of the on-board adaptive optics of adaptive filtration as a way to improve the efficiency of adaptive optical systems. The project in mind is to use obtained results

Organization of an optimal adaptive immune system

Science.gov (United States)

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.

Adaptive polymeric system for Hebbian type learning

OpenAIRE

2011-01-01

Abstract We present the experimental realization of an adaptive polymeric system displaying a ?learning behaviour?. The system consists on a statistically organized networks of memristive elements (memory-resitors) based on polyaniline. In a such network the path followed by the current increments its conductivity, a property which makes the system able to mimic Hebbian type learning and have application in hardware neural networks. After discussing the working principle of ...

ℋ∞ Adaptive observer for nonlinear fractional-order systems

KAUST Repository

Ndoye, Ibrahima

2016-06-23

In this paper, an adaptive observer is proposed for the joint estimation of states and parameters of a fractional nonlinear system with external perturbations. The convergence of the proposed observer is derived in terms of linear matrix inequalities (LMIs) by using an indirect Lyapunov method.The proposed ℋ∞ adaptive observer is also robust against Lipschitz additive nonlinear uncertainty. The performance of the observer is illustrated through some examples including the chaotic Lorenz and Lü\\'s systems. © 2016 John Wiley & Sons, Ltd.

On complex adaptive systems and terrorism

International Nuclear Information System (INIS)

Ahmed, E.; Elgazzar, A.S.; Hegazi, A.S.

2005-01-01

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

Adaptive fuzzy controller based MPPT for photovoltaic systems

International Nuclear Information System (INIS)

Guenounou, Ouahib; Dahhou, Boutaib; Chabour, Ferhat

2014-01-01

Highlights: • We propose a fuzzy controller with adaptive output scaling factor as a maximum power point tracker of photovoltaic system. • The proposed controller integrates two different rule bases defined on error and change of error. • Our controller can track the maximum power point with better performances when compared to its conventional counterpart. - Abstract: This paper presents an intelligent approach to optimize the performances of photovoltaic systems. The system consists of a PV panel, a DC–DC boost converter, a maximum power point tracker controller and a resistive load. The key idea of the proposed approach is the use of a fuzzy controller with an adaptive gain as a maximum power point tracker. The proposed controller integrates two different rule bases. The first is used to adjust the duty cycle of the boost converter as in the case of a conventional fuzzy controller while the second rule base is designed for an online adjusting of the controller’s gain. The performances of the adaptive fuzzy controller are compared with those obtained using a conventional fuzzy controllers with different gains and in each case, the proposed controller outperforms its conventional counterpart

Adaptive H∞ synchronization of chaotic systems via linear and nonlinear feedback control

International Nuclear Information System (INIS)

Fu Shi-Hui; Lu Qi-Shao; Du Ying

2012-01-01

Adaptive H ∞ synchronization of chaotic systems via linear and nonlinear feedback control is investigated. The chaotic systems are redesigned by using the generalized Hamiltonian systems and observer approach. Based on Lyapunov's stability theory, linear and nonlinear feedback control of adaptive H ∞ synchronization is established in order to not only guarantee stable synchronization of both master and slave systems but also reduce the effect of external disturbance on an H ∞ -norm constraint. Adaptive H ∞ synchronization of chaotic systems via three kinds of control is investigated with applications to Lorenz and Chen systems. Numerical simulations are also given to identify the effectiveness of the theoretical analysis. (general)

Adaptive Disturbance Rejection Control for Automatic Carrier Landing System

Directory of Open Access Journals (Sweden)

Xin Wang

2016-01-01

Full Text Available An adaptive disturbance rejection algorithm is proposed for carrier landing system in the final-approach. The carrier-based aircraft dynamics and the linearized longitudinal model under turbulence conditions in the final-approach are analyzed. A stable adaptive control scheme is developed based on LDU decomposition of the high-frequency gain matrix, which ensures closed-loop stability and asymptotic output tracking. Finally, simulation studies of a linearized longitudinal-directional dynamics model are conducted to demonstrate the performance of the adaptive scheme.

Modeling and Control of Magnetic Fluid Deformable Mirrors for Adaptive Optics Systems

CERN Document Server

Wu, Zhizheng; Ben Amara, Foued

2013-01-01

Modeling and Control of Magnetic Fluid Deformable Mirrors for Adaptive Optics Systems presents a novel design of wavefront correctors based on magnetic fluid deformable mirrors (MFDM) as well as corresponding control algorithms. The presented wavefront correctors are characterized by their linear, dynamic response. Various mirror surface shape control algorithms are presented along with experimental evaluations of the performance of the resulting adaptive optics systems. Adaptive optics (AO) systems are used in various fields of application to enhance the performance of optical systems, such as imaging, laser, free space optical communication systems, etc. This book is intended for undergraduate and graduate students, professors, engineers, scientists and researchers working on the design of adaptive optics systems and their various emerging fields of application. Zhizheng Wu is an associate professor at Shanghai University, China. Azhar Iqbal is a research associate at the University of Toronto, Canada. Foue...

Synchronization of a modified Chua's circuit system via adaptive sliding mode control

International Nuclear Information System (INIS)

Yan, J.-J.; Lin, J.-S.; Liao, T.-L.

2008-01-01

This study addresses the adaptive synchronization of a modified Chua's circuit system with both unknown system parameters and the nonlinearity in the control input. An adaptive switching surface is newly adopted such that it becomes easy to ensure the stability of the error dynamics in the sliding mode. Based on this adaptive switching surface, an adaptive sliding mode controller (ASMC) is derived to guarantee the occurrence of the sliding motion, even when the system is undergoing input nonlinearity. This method can also be easily extended to a general class of Chua's circuits. An illustrative example is given to show the applicability of the proposed ASMC design

Adaptive generalized combination complex synchronization of uncertain real and complex nonlinear systems

Energy Technology Data Exchange (ETDEWEB)

Wang, Shi-bing, E-mail: wang-shibing@dlut.edu.cn, E-mail: wangxy@dlut.edu.cn [School of Computer and Information Engineering, Fuyang Normal University, Fuyang 236041 (China); Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, Dalian 116024 (China); Wang, Xing-yuan, E-mail: wang-shibing@dlut.edu.cn, E-mail: wangxy@dlut.edu.cn [Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, Dalian 116024 (China); Wang, Xiu-you [School of Computer and Information Engineering, Fuyang Normal University, Fuyang 236041 (China); Zhou, Yu-fei [College of Electrical Engineering and Automation, Anhui University, Hefei 230601 (China)

2016-04-15

With comprehensive consideration of generalized synchronization, combination synchronization and adaptive control, this paper investigates a novel adaptive generalized combination complex synchronization (AGCCS) scheme for different real and complex nonlinear systems with unknown parameters. On the basis of Lyapunov stability theory and adaptive control, an AGCCS controller and parameter update laws are derived to achieve synchronization and parameter identification of two real drive systems and a complex response system, as well as two complex drive systems and a real response system. Two simulation examples, namely, ACGCS for chaotic real Lorenz and Chen systems driving a hyperchaotic complex Lü system, and hyperchaotic complex Lorenz and Chen systems driving a real chaotic Lü system, are presented to verify the feasibility and effectiveness of the proposed scheme.

Adaptive radiotherapy using helical tomotherapy system

International Nuclear Information System (INIS)

Jeswani, Sam; Ruchala, Kenneth; Olivera, Gustavo; Mackie, T.R.

2008-01-01

As commonly known in the field, adaptive radiation therapy (ART) is the use of feedback to modify a radiotherapy treatment. There are numerous ways in which this feedback can be received and used, and this presentation will discuss some of the implementations of ART being investigated with a helical TomoTherapy system

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

Science.gov (United States)

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…

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

Science.gov (United States)

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.

Adaptive Observer-Based Fault-Tolerant Control Design for Uncertain Systems

Directory of Open Access Journals (Sweden)

Huaming Qian

2015-01-01

Full Text Available This study focuses on the design of the robust fault-tolerant control (FTC system based on adaptive observer for uncertain linear time invariant (LTI systems. In order to improve robustness, rapidity, and accuracy of traditional fault estimation algorithm, an adaptive fault estimation algorithm (AFEA using an augmented observer is presented. By utilizing a new fault estimator model, an improved AFEA based on linear matrix inequality (LMI technique is proposed to increase the performance. Furthermore, an observer-based state feedback fault-tolerant control strategy is designed, which guarantees the stability and performance of the faulty system. Moreover, the adaptive observer and the fault-tolerant controller are designed separately, whose performance can be considered, respectively. Finally, simulation results of an aircraft application are presented to illustrate the effectiveness of the proposed design methods.

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

Science.gov (United States)

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.

Adaptive Management of Computing and Network Resources for Spacecraft Systems

Science.gov (United States)

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.

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

Directory of Open Access Journals (Sweden)

Borsika A. Rabin

2018-04-01

Full Text Available BackgroundMany 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.Materials and methodsThis 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.ResultsThe 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

Adaptive fuzzy sliding-mode control for multi-input multi-output chaotic systems

International Nuclear Information System (INIS)

Poursamad, Amir; Markazi, Amir H.D.

2009-01-01

This paper describes an adaptive fuzzy sliding-mode control algorithm for controlling unknown or uncertain, multi-input multi-output (MIMO), possibly chaotic, dynamical systems. The control approach encompasses a fuzzy system and a robust controller. The fuzzy system is designed to mimic an ideal sliding-mode controller, and the robust controller compensates the difference between the fuzzy controller and the ideal one. The parameters of the fuzzy system, as well as the uncertainty bound of the robust controller, are tuned adaptively. The adaptive laws are derived in the Lyapunov sense to guarantee the asymptotic stability and tracking of the controlled system. The effectiveness of the proposed method is shown by applying it to some well-known chaotic systems.

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

Science.gov (United States)

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.

Towards Static Analysis of Policy-Based Self-adaptive Computing Systems

DEFF Research Database (Denmark)

Margheri, Andrea; Nielson, Hanne Riis; Nielson, Flemming

2016-01-01

For supporting the design of self-adaptive computing systems, the PSCEL language offers a principled approach that relies on declarative definitions of adaptation and authorisation policies enforced at runtime. Policies permit managing system components by regulating their interactions...... and by dynamically introducing new actions to accomplish task-oriented goals. However, the runtime evaluation of policies and their effects on system components make the prediction of system behaviour challenging. In this paper, we introduce the construction of a flow graph that statically points out the policy...... evaluations that can take place at runtime and exploit it to analyse the effects of policy evaluations on the progress of system components....

Processing and Linguistics Properties of Adaptable Systems

Directory of Open Access Journals (Sweden)

Dumitru TODOROI

2006-01-01

Full Text Available Continuation and development of the research in Adaptable Programming Initialization [Tod-05.1,2,3] is presented. As continuation of [Tod-05.2,3] in this paper metalinguistic tools used in the process of introduction of new constructions (data, operations, instructions and controls are developed. The generalization schemes of evaluation of adaptable languages and systems are discussed. These results analogically with [Tod-05.2,3] are obtained by the team, composed from the researchers D. Todoroi [Tod-05.4], Z. Todoroi [ZTod-05], and D. Micusa [Mic-03]. Presented results will be included in the book [Tod-06].

IAE-adaptive Kalman filter for INS/GPS integrated navigation system

Institute of Scientific and Technical Information of China (English)

Bian Hongwei; Jin Zhihua; Tian Weifeng

2006-01-01

A marine INS/GPS adaptive navigation system is presented in this paper. GPS with two antenna providing vessel's altitude is selected as the auxiliary system fusing with INS to improve the performance of the hybrid system. The Kalman filter is the most frequently used algorithm in the integrated navigation system, which is capable of estimating INS errors online based on the measured errors between INS and GPS. The standard Kalman filter (SKF) assumes that the statistics of the noise on each sensor are given. As long as the noise distributions do not change, the Kalman filter will give the optimal estimation. However GPS receiver will be disturbed easily and thus temporally changing measurement noise will join into the outputs of GPS, which will lead to performance degradation of the Kalman filter. Many researchers introduce fuzzy logic control method into innovation-based adaptive estimation adaptive Kalman filtering (IAE-AKF) algorithm, and accordingly propose various adaptive Kalman filters. However how to design the fuzzy logic controller is a very complicated problem still without a convincing solution. A novel IAE-AKF is proposed herein, which is based on the maximum likelihood criterion for the proper computation of the filter innovation covariance and hence of the filter gain. The approach is direct and simple without having to establish fuzzy inference rules. After having deduced the proposed IAE-AKF algorithm theoretically in detail, the approach is tested by the simulation based on the system error model of the developed INS/GPS integrated marine navigation system. Simulation results show that the adaptive Kalman filter outperforms the SKF with higher accuracy, robustness and less computation. It is demonstrated that this proposed approach is a valid solution for the unknown changing measurement noise exited in the Kalman filter.

Adaptive observer based synchronization of a class of uncertain chaotic systems

International Nuclear Information System (INIS)

Bowong, S.; Yamapi, R.

2005-05-01

This study addresses the adaptive synchronization of a class of uncertain chaotic systems in the drive-response framework. For a class of uncertain chaotic systems with unknown parameters and external disturbances, a robust adaptive observer based response system is constructed to synchronize the uncertain chaotic system. Lyapunov stability theory and Barbalat lemma ensure the global synchronization between the drive and response systems even if Lipschitz constants on function matrices and bounds on uncertainties are unknown. Numerical simulation of the Genesio-Tesi system verifies the effectiveness of the proposed method. (author)

Adaptive fuzzy trajectory control for biaxial motion stage system

Directory of Open Access Journals (Sweden)

Wei-Lung Mao

2016-04-01

Full Text Available Motion control is an essential part of industrial machinery and manufacturing systems. In this article, the adaptive fuzzy controller is proposed for precision trajectory tracking control in biaxial X-Y motion stage system. The theoretical analyses of direct fuzzy control which is insensitive to parameter uncertainties and external load disturbances are derived to demonstrate the feasibility to track the reference trajectories. The Lyapunov stability theorem has been used to testify the asymptotic stability of the whole system, and all the signals are bounded in the closed-loop system. The intelligent position controller combines the merits of the adaptive fuzzy control with robust characteristics and learning ability for periodic command tracking of a servo drive mechanism. The simulation and experimental results on square, triangle, star, and circle reference contours are presented to show that the proposed controller indeed accomplishes the better tracking performances with regard to model uncertainties. It is observed that the convergence of parameters and tracking errors can be faster and smaller compared with the conventional adaptive fuzzy control in terms of average tracking error and tracking error standard deviation.

Quantifying adaptive evolution in the Drosophila immune system.

Directory of Open Access Journals (Sweden)

Darren J Obbard

2009-10-01

Full Text Available It is estimated that a large proportion of amino acid substitutions in Drosophila have been fixed by natural selection, and as organisms are faced with an ever-changing array of pathogens and parasites to which they must adapt, we have investigated the role of parasite-mediated selection as a likely cause. To quantify the effect, and to identify which genes and pathways are most likely to be involved in the host-parasite arms race, we have re-sequenced population samples of 136 immunity and 287 position-matched non-immunity genes in two species of Drosophila. Using these data, and a new extension of the McDonald-Kreitman approach, we estimate that natural selection fixes advantageous amino acid changes in immunity genes at nearly double the rate of other genes. We find the rate of adaptive evolution in immunity genes is also more variable than other genes, with a small subset of immune genes evolving under intense selection. These genes, which are likely to represent hotspots of host-parasite coevolution, tend to share similar functions or belong to the same pathways, such as the antiviral RNAi pathway and the IMD signalling pathway. These patterns appear to be general features of immune system evolution in both species, as rates of adaptive evolution are correlated between the D. melanogaster and D. simulans lineages. In summary, our data provide quantitative estimates of the elevated rate of adaptive evolution in immune system genes relative to the rest of the genome, and they suggest that adaptation to parasites is an important force driving molecular evolution.

Financial markets as adaptive systems

Science.gov (United States)

Potters, M.; Cont, R.; Bouchaud, J.-P.

1998-02-01

We show, by studying in detail the market prices of options on liquid markets, that the market has empirically corrected the simple, but inadequate Black-Scholes formula to account for two important statistical features of asset fluctuations: "fat tails" and correlations in the scale of fluctuations. These aspects, although not included in the pricing models, are very precisely reflected in the price fixed by the market as a whole. Financial markets thus behave as rather efficient adaptive systems.

An adaptive robust controller for time delay maglev transportation systems

Science.gov (United States)

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.

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

Science.gov (United States)

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

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

Science.gov (United States)

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…

Ultra Linear Low-loss Varactors & Circuits for Adaptive RF Systems

NARCIS (Netherlands)

Huang, C.

2010-01-01

With the evolution of wireless communication, varactors can play an important role in enabling adaptive transceivers as well as phase-diversity systems. This thesis presents various varactor diode-based circuit topologies that facilitate RF adaptivity. The proposed varactor configurations can act as

The higher school teaching staff professional development system creation on the adaptive management principles

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Borova T.A.

2012-03-01

Full Text Available The article deals with theoretical analysis of the higher school teaching staff professional development system creation on the adaptive management principles. It is determined the background and components of the higher school teaching staff professional development adaptive management system. It is specified the mechanisms for higher school teaching staff professional development adaptive management: monitoring and coaching. It is shown their place in the higher school teaching staff professional development system on the adaptive management principles. The results of the system efficiency are singled out.

Adaptive Sliding Control for a Class of Fractional Commensurate Order Chaotic Systems

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Jian Yuan

2015-01-01

Full Text Available This paper proposes adaptive sliding mode control design for a class of fractional commensurate order chaotic systems. We firstly introduce a fractional integral sliding manifold for the nominal systems. Secondly we prove the stability of the corresponding fractional sliding dynamics. Then, by introducing a Lyapunov candidate function and using the Mittag-Leffler stability theory we derive the desired sliding control law. Furthermore, we prove that the proposed sliding manifold is also adapted for the fractional systems in the presence of uncertainties and external disturbances. At last, we design a fractional adaptation law for the perturbed fractional systems. To verify the viability and efficiency of the proposed fractional controllers, numerical simulations of fractional Lorenz’s system and Chen’s system are presented.

Guiding climate change adaptation within vulnerable natural resource management systems.

Science.gov (United States)

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.

Guiding Climate Change Adaptation Within Vulnerable Natural Resource Management Systems

Science.gov (United States)

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.

Adaptive cyber-attack modeling system

Science.gov (United States)

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.

Environment Adaptive Lighting Systems for Smart Homes

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Cem Mehmet Catalbas

2017-09-01

Full Text Available In this work, an application of adaptive lighting system is proposed for smart homes. In this paper, it is suggested that, an intelligent lighting system with outdoor adaptation can be realized via a real fisheye image. During the implementation of the proposed method, the fuzzy c-means method, which is a commonly used data clustering method, has been used. The input image is divided into three different regions according to its brightness levels. Then, the RGB image is converted to CIE 1931 XYZ color space; and the obtained XYZ values are converted to x and y values. The parameters of x and y values are shown in CIE Chromaticity Diagram for different regions in the sky. Thereafter, the coordinate values are converted to Correlated Color Temperature by using two different formulas. Additionally, the conversion results are examined with respect to actual and estimated CCT values.

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Adaptive stimulus optimization for sensory systems neuroscience.

Science.gov (United States)

DiMattina, Christopher; Zhang, Kechen

2013-01-01

In this paper, we review several lines of recent work aimed at developing practical methods for adaptive on-line stimulus generation for sensory neurophysiology. We consider various experimental paradigms where on-line stimulus optimization is utilized, including the classical optimal stimulus paradigm where the goal of experiments is to identify a stimulus which maximizes neural responses, the iso-response paradigm which finds sets of stimuli giving rise to constant responses, and the system identification paradigm where the experimental goal is to estimate and possibly compare sensory processing models. We discuss various theoretical and practical aspects of adaptive firing rate optimization, including optimization with stimulus space constraints, firing rate adaptation, and possible network constraints on the optimal stimulus. We consider the problem of system identification, and show how accurate estimation of non-linear models can be highly dependent on the stimulus set used to probe the network. We suggest that optimizing stimuli for accurate model estimation may make it possible to successfully identify non-linear models which are otherwise intractable, and summarize several recent studies of this type. Finally, we present a two-stage stimulus design procedure which combines the dual goals of model estimation and model comparison and may be especially useful for system identification experiments where the appropriate model is unknown beforehand. We propose that fast, on-line stimulus optimization enabled by increasing computer power can make it practical to move sensory neuroscience away from a descriptive paradigm and toward a new paradigm of real-time model estimation and comparison.

Risk-return relationship in a complex adaptive system.

Directory of Open Access Journals (Sweden)

Kunyu Song

Full Text Available 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.

Risk-return relationship in a complex adaptive system.

Science.gov (United States)

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.

Adaptive and neuroadaptive control for nonnegative and compartmental dynamical systems

Science.gov (United States)

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

Control and adaptation in telecommunication systems mathematical foundations

CERN Document Server

Popovskij, Vladimir; Titarenko, Larysa

2011-01-01

This book is devoted to mathematical foundations providing synthesis and analysis of control and adaptation algorithms targeting modern telecommunication systems (TCS). The most popular technologies and network management methods are discussed.

Chaotic Secure Communication Systems with an Adaptive State Observer

Directory of Open Access Journals (Sweden)

Wei-Der Chang

2015-01-01

Full Text Available This paper develops a new digital communication scheme based on using a unified chaotic system and an adaptive state observer. The proposed communication system basically consists of five important elements: signal modulation, chaotic encryption, adaptive state observer, chaotic decryption, and signal demodulation. A sequence of digital signals will be delivered from the transmitter to the receiver through a public channel. It is rather reasonable that if the number of signals delivered on the public channel is fewer, then the security of such communication system is more guaranteed. Therefore, in order to achieve this purpose, a state observer will be designed and its function is to estimate full system states only by using the system output signals. In this way, the signals delivered on the public channel can be reduced mostly. According to these estimated state signals, the original digital sequences are then retrieved completely. Finally, experiment results are provided to verify the applicability of the proposed communication system.

Adaptive synchronization of Rossler system with uncertain parameters

International Nuclear Information System (INIS)

Park, Ju H.

2005-01-01

This article addresses control for the chaos synchronization of Rossler systems with three uncertain parameters. Based on the Lyapunov stability theory, an adaptive control law is derived to make the states of two identical Rossler systems asymptotically synchronized. A numerical simulations is presented to show the effectiveness of the proposed chaos synchronization scheme

The role of the adaptive immune system in regulation of gut microbiota.

Science.gov (United States)

Kato, Lucia M; Kawamoto, Shimpei; Maruya, Mikako; Fagarasan, Sidonia

2014-07-01

The gut nourishes rich bacterial communities that affect profoundly the functions of the immune system. The relationship between gut microbiota and the immune system is one of reciprocity. The microbiota contributes to nutrient processing and the development, maturation, and function of the immune system. Conversely, the immune system, particularly the adaptive immune system, plays a key role in shaping the repertoire of gut microbiota. The fitness of host immune system is reflected in the gut microbiota, and deficiencies in either innate or adaptive immunity impact on diversity and structures of bacterial communities in the gut. Here, we discuss the mechanisms that underlie this reciprocity and emphasize how the adaptive immune system via immunoglobulins (i.e. IgA) contributes to diversification and balance of gut microbiota required for immune homeostasis. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Adaptive Wavelet Coding Applied in a Wireless Control System.

Science.gov (United States)

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.

Adaptive Wavelet Coding Applied in a Wireless Control System

Directory of Open Access Journals (Sweden)

Felipe O. S. Gama

2017-12-01

Full Text Available 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.

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

Science.gov (United States)

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...

On the Adaptation of an Agile Information Systems Development Method

NARCIS (Netherlands)

Aydin, M.N.; Harmsen, F.; van Slooten, C.; Stegwee, R.A.

2005-01-01

Little specific research has been conducted to date on the adaptation of agile information systems development (ISD) methods. This article presents the work practice in dealing with the adaptation of such a method in the ISD department of one of the leading financial institutes in Europe. Two forms

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

Science.gov (United States)

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.

The beauty of simple adaptive control and new developments in nonlinear systems stability analysis

Energy Technology Data Exchange (ETDEWEB)

Barkana, Itzhak, E-mail: ibarkana@gmail.com [BARKANA Consulting, Ramat Hasharon (Israel)

2014-12-10

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 measure 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.

ADEX optimized adaptive controllers and systems from research to industrial practice

CERN Document Server

Martín-Sánchez, Juan M

2015-01-01

This book is a didactic explanation of the developments of predictive, adaptive predictive and optimized adaptive control, including the latest methodology of adaptive predictive expert (ADEX) control, and their practical applications. It is focused on the stability perspective, used in the introduction of these methodologies, and is divided into six parts, with exercises and real-time simulations provided for the reader as appropriate. ADEX Optimized Adaptive Controllers and Systems begins with the conceptual and intuitive knowledge of the technology and derives the stability conditions to be verified by the driver block and the adaptive mechanism of the optimized adaptive controller to guarantee achievement of desired control performance. The second and third parts are centered on the design of the driver block and adaptive mechanism, which verify these stability conditions. The authors then proceed to detail the stability theory that supports predictive, adaptive predictive and optimized adaptive control m...

Extensible Adaptive System for STEM Learning

Science.gov (United States)

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

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

Science.gov (United States)

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.

Adaptive intrusion data system (AIDS) software routines

International Nuclear Information System (INIS)

Corlis, N.E.

1980-07-01

An Adaptive Intrusion Data System (AIDS) was developed to collect information from intrusion alarm sensors as part of an evaluation system to improve sensor performance. AIDS is a unique digital data-compression, storage, and formatting system; it also incorporates a capability for video selection and recording for assessment of the sensors monitored by the system. The system is software reprogrammable to numerous configurations that may be used for the collection of environmental, bilevel, analog, and video data. This report describes the software routines that control the different AIDS data-collection modes, the diagnostic programs to test the operating hardware, and the data format. Sample data printouts are also included

Spoken language identification system adaptation in under-resourced environments

CSIR Research Space (South Africa)

Kleynhans, N

2013-12-01

Full Text Available Speech Recognition (ASR) systems in the developing world is severely inhibited. Given that few task-specific corpora exist and speech technology systems perform poorly when deployed in a new environment, we investigate the use of acoustic model adaptation...

Evaluate the interactive and reusable service in adaptive on demand applications

OpenAIRE

Hwang , Chyi-Wen

2007-01-01

In this paper, the researcher based on the open platforms and tools for personalized learning idea, with the “ Interactive & reusable” function in UI design model, directly dealing with Knowledge on demand (KOD) service from the aspect-oriented and object-oriented issue. Moreover, to propose the KOD combine with VOD (Video on Demand); AOD (Audio on Demand); COD (Course on Demand) and IOD (Information on Demand in Global index searching) in diversity of hypermedia metadata.

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

Science.gov (United States)

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.

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

Science.gov (United States)

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…

Modeling of memristor-based chaotic systems using nonlinear Wiener adaptive filters based on backslash operator

International Nuclear Information System (INIS)

Zhao, Yibo; Jiang, Yi; Feng, Jiuchao; Wu, Lifu

2016-01-01

Highlights: • A novel nonlinear Wiener adaptive filters based on the backslash operator are proposed. • The identification approach to the memristor-based chaotic systems using the proposed adaptive filters. • The weight update algorithm and convergence characteristics for the proposed adaptive filters are derived. - Abstract: Memristor-based chaotic systems have complex dynamical behaviors, which are characterized as nonlinear and hysteresis characteristics. Modeling and identification of their nonlinear model is an important premise for analyzing the dynamical behavior of the memristor-based chaotic systems. This paper presents a novel nonlinear Wiener adaptive filtering identification approach to the memristor-based chaotic systems. The linear part of Wiener model consists of the linear transversal adaptive filters, the nonlinear part consists of nonlinear adaptive filters based on the backslash operator for the hysteresis characteristics of the memristor. The weight update algorithms for the linear and nonlinear adaptive filters are derived. Final computer simulation results show the effectiveness as well as fast convergence characteristics. Comparing with the adaptive nonlinear polynomial filters, the proposed nonlinear adaptive filters have less identification error.

Towards Adaptive Spoken Dialog Systems

CERN Document Server

Schmitt, Alexander

2013-01-01

In Monitoring Adaptive Spoken Dialog Systems, authors Alexander Schmitt and Wolfgang Minker investigate statistical approaches that allow for recognition of negative dialog patterns in Spoken Dialog Systems (SDS). The presented stochastic methods allow a flexible, portable and  accurate use.  Beginning with the foundations of machine learning and pattern recognition, this monograph examines how frequently users show negative emotions in spoken dialog systems and develop novel approaches to speech-based emotion recognition using hybrid approach to model emotions. The authors make use of statistical methods based on acoustic, linguistic and contextual features to examine the relationship between the interaction flow and the occurrence of emotions using non-acted  recordings several thousand real users from commercial and non-commercial SDS. Additionally, the authors present novel statistical methods that spot problems within a dialog based on interaction patterns. The approaches enable future SDS to offer m...

L1 Adaptive Control for a Vertical Rotor Orientation System

Directory of Open Access Journals (Sweden)

Sijia Liu

2016-08-01

Full Text Available Bottom-fixed vertical rotating devices are widely used in industrial and civilian fields. The free upside of the rotor will cause vibration and lead to noise and damage during operation. Meanwhile, parameter uncertainties, nonlinearities and external disturbances will further deteriorate the performance of the rotor. Therefore, in this paper, we present a rotor orientation control system based on an active magnetic bearing with L 1 adaptive control to restrain the influence of the nonlinearity and uncertainty and reduce the vibration amplitude of the vertical rotor. The boundedness and stability of the adaptive system are analyzed via a theoretical derivation. The impact of the adaptive gain is discussed through simulation. An experimental rig based on dSPACE is designed to test the validity of the rotor orientation system. The experimental results show that the relative vibration amplitude of the rotor using the L 1 adaptive controller will be reduced to ∼50% of that in the initial state, which is a 10% greater reduction than can be achieved with the nonadaptive controller. The control approach in this paper is of some significance to solve the orientation control problem in a low-speed vertical rotor with uncertainties and nonlinearities.

Adaptive Embedded Systems – Challenges of Run-Time Resource Management

DEFF Research Database (Denmark)

Understanding and efficiently controlling the dynamic behavior of adaptive embedded systems is a challenging endavor. The challenges come from the often very complicated interplay between the application, the application mapping, and the underlying hardware architecture. With MPSoC, we have...... the technology to design and fabricate dynamically reconfigurable hardware platforms. However, such platforms will pose new challenges to tools and methods to efficiently explore these platforms at run-time. This talk will address some of the challenges of run-time resource management in adaptive embedded...... systems....

Adaptive control of nonlinear in parameters chaotic system via Lyapunov exponents placement

Energy Technology Data Exchange (ETDEWEB)

Ayati, Moosa [Department of Electrical Engineering, K.N. Toosi University of Technology, Sayyed Khandan Bridge, Shariati Street, Tehran (Iran, Islamic Republic of)], E-mail: Ayati@dena.kntu.ac.ir; Khaki-Sedigh, Ali [Department of Electrical Engineering, K.N. Toosi University of Technology, Sayyed Khandan Bridge, Shariati Street, Tehran (Iran, Islamic Republic of)], E-mail: sedigh@kntu.ac.ir

2009-08-30

This paper proposes a new method for the adaptive control of nonlinear in parameters (NLP) chaotic systems. A method based on Lagrangian of a cost function is used to identify the parameters of the system. Estimation results are used to calculate the Lyapunov exponents adaptively. Finally, the Lyapunov exponents placement method is used to assign the desired Lyapunov exponents of the closed loop system.

Adaptive control of nonlinear in parameters chaotic system via Lyapunov exponents placement

International Nuclear Information System (INIS)

Ayati, Moosa; Khaki-Sedigh, Ali

2009-01-01

This paper proposes a new method for the adaptive control of nonlinear in parameters (NLP) chaotic systems. A method based on Lagrangian of a cost function is used to identify the parameters of the system. Estimation results are used to calculate the Lyapunov exponents adaptively. Finally, the Lyapunov exponents placement method is used to assign the desired Lyapunov exponents of the closed loop system.

Water System Adaptation to Hydrological Changes: Module 1, Introduction to Water System Adaptation

Science.gov (United States)

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, ...

Creating adaptive web recommendation system based on user behavior

Science.gov (United States)

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.

Models, methods and software tools for building complex adaptive traffic systems

International Nuclear Information System (INIS)

Alyushin, S.A.

2011-01-01

The paper studies the modern methods and tools to simulate the behavior of complex adaptive systems (CAS), the existing systems of traffic modeling in simulators and their characteristics; proposes requirements for assessing the suitability of the system to simulate the CAS behavior in simulators. The author has developed a model of adaptive agent representation and its functioning environment to meet certain requirements set above, and has presented methods of agents' interactions and methods of conflict resolution in simulated traffic situations. A simulation system realizing computer modeling for simulating the behavior of CAS in traffic situations has been created [ru

Adaptive control of chaotic systems with stochastic time varying unknown parameters

Energy Technology Data Exchange (ETDEWEB)

Salarieh, Hassan [Center of Excellence in Design, Robotics and Automation, Department of Mechanical Engineering, Sharif University of Technology, P.O. Box 11365-9567, Azadi Avenue, Tehran (Iran, Islamic Republic of)], E-mail: salarieh@mech.sharif.edu; Alasty, Aria [Center of Excellence in Design, Robotics and Automation, Department of Mechanical Engineering, Sharif University of Technology, P.O. Box 11365-9567, Azadi Avenue, Tehran (Iran, Islamic Republic of)], E-mail: aalasti@sharif.edu

2008-10-15

In this paper based on the Lyapunov stability theorem, an adaptive control scheme is proposed for stabilizing the unstable periodic orbits (UPO) of chaotic systems. It is assumed that the chaotic system has some linearly dependent unknown parameters which are stochastically time varying. The stochastic parameters are modeled through the Weiner process derivative. To demonstrate the effectiveness of the proposed technique it has been applied to the Lorenz, Chen and Rossler dynamical systems, as some case studies. Simulation results indicate that the proposed adaptive controller has a high performance in stabilizing the UPO of chaotic systems in noisy environment.

Quantum Information Biology: From Theory of Open Quantum Systems to Adaptive Dynamics

Science.gov (United States)

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.

A Bacterial-Based Algorithm to Simulate Complex Adaptative Systems

OpenAIRE

González Rodríguez, Diego; Hernández Carrión, José Rodolfo

2014-01-01

Paper presented at the 13th International Conference on Simulation of Adaptive Behavior which took place at Castellón, Spain in 2014, July 22-25. Bacteria have demonstrated an amazing capacity to overcome envi-ronmental changes by collective adaptation through genetic exchanges. Using a distributed communication system and sharing individual strategies, bacteria propagate mutations as innovations that allow them to survive in different envi-ronments. In this paper we present an agent-based...

Use of sensitivity-information for the adaptive simulation of thermo-hydraulic system codes

International Nuclear Information System (INIS)

Kerner, Alexander M.

2011-01-01

Within the scope of this thesis the development of methods for online-adaptation of dynamical plant simulations of a thermal-hydraulic system code to measurement data is depicted. The described approaches are mainly based on the use of sensitivity-information in different areas: statistical sensitivity measures are used for the identification of the parameters to be adapted and online-sensitivities for the parameter adjustment itself. For the parameter adjustment the method of a ''system-adapted heuristic adaptation with partial separation'' (SAHAT) was developed, which combines certain variants of parameter estimation and control with supporting procedures to solve the basic problems. The applicability of the methods is shown by adaptive simulations of a PKL-III experiment and by selected transients in a nuclear power plant. Finally the main perspectives for the application of a tracking simulator on a system code are identified.

A Conceptual Framework for Planning Systemic Human Adaptation to Global Warming

Directory of Open Access Journals (Sweden)

Peter W. Tait

2015-08-01

Full Text Available 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.

A Conceptual Framework for Planning Systemic Human Adaptation to Global Warming

Science.gov (United States)

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

Adaptive Sensing Based on Profiles for Sensor Systems

Directory of Open Access Journals (Sweden)

Yoshiteru Ishida

2009-10-01

Full Text Available This paper proposes a profile-based sensing framework for adaptive sensor systems based on models that relate possibly heterogeneous sensor data and profiles generated by the models to detect events. With these concepts, three phases for building the sensor systems are extracted from two examples: a combustion control sensor system for an automobile engine, and a sensor system for home security. The three phases are: modeling, profiling, and managing trade-offs. Designing and building a sensor system involves mapping the signals to a model to achieve a given mission.

A Model of Internal Communication in Adaptive Communication Systems.

Science.gov (United States)

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…

Livestock in a changing climate: production system transitions as an adaptation strategy for agriculture

International Nuclear Information System (INIS)

Weindl, Isabelle; Lotze-Campen, Hermann; Popp, Alexander; Müller, Christoph; Schmitz, Christoph; Rolinski, Susanne; Havlík, Petr; Herrero, Mario

2015-01-01

Livestock farming is the world’s largest land use sector and utilizes around 60% of the global biomass harvest. Over the coming decades, climate change will affect the natural resource base of livestock production, especially the productivity of rangeland and feed crops. Based on a comprehensive impact modeling chain, we assess implications of different climate projections for agricultural production costs and land use change and explore the effectiveness of livestock system transitions as an adaptation strategy. Simulated climate impacts on crop yields and rangeland productivity generate adaptation costs amounting to 3% of total agricultural production costs in 2045 (i.e. 145 billion US$). Shifts in livestock production towards mixed crop-livestock systems represent a resource- and cost-efficient adaptation option, reducing agricultural adaptation costs to 0.3% of total production costs and simultaneously abating deforestation by about 76 million ha globally. The relatively positive climate impacts on grass yields compared with crop yields favor grazing systems inter alia in South Asia and North America. Incomplete transitions in production systems already have a strong adaptive and cost reducing effect: a 50% shift to mixed systems lowers agricultural adaptation costs to 0.8%. General responses of production costs to system transitions are robust across different global climate and crop models as well as regarding assumptions on CO 2 fertilization, but simulated values show a large variation. In the face of these uncertainties, public policy support for transforming livestock production systems provides an important lever to improve agricultural resource management and lower adaptation costs, possibly even contributing to emission reduction. (letter)

Adaptive infrared-reflecting systems inspired by cephalopods

Science.gov (United States)

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.

An Immune-inspired Adaptive Automated Intrusion Response System Model

Directory of Open Access Journals (Sweden)

Ling-xi Peng

2012-09-01

Full Text Available An immune-inspired adaptive automated intrusion response system model, named as , is proposed. The descriptions of self, non-self, immunocyte, memory detector, mature detector and immature detector of the network transactions, and the realtime network danger evaluation equations are given. Then, the automated response polices are adaptively performed or adjusted according to the realtime network danger. Thus, not only accurately evaluates the network attacks, but also greatly reduces the response times and response costs.

The plasma membrane transport systems and adaptation to salinity.

Science.gov (United States)

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.

A full XML-based approach to creating hypermedia learning modules in web-based environments: application to a pathology course.

Science.gov (United States)

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.

Adaptive antenna system by ESP32-PICO-D4 and its application to web radio system

Directory of Open Access Journals (Sweden)

Toshiro Kodera

2018-04-01

Full Text Available Adaptive antenna technique has an important role in the IoT environment in order to establish reliable and stable wireless communication in high congestion situation. Even if knowing antenna characteristics in advance, electromagnetic wave propagation in non-line-of-sight environment is very complex and unpredictable, therefore, the adjustment the antenna radiation for the optimum signal reception is important for the better wireless link. This article presents a simple but effective adaptive antenna system for Wi-Fi utilizing the function of a highly integrated component, ESP32-PICO-D4. This chip is a system-in-chip containing all components for Wi-Fi and Bluetooth application except for antenna. Together with SP3T RF switch and dielectric antennas and high-resolution audio DAC, completed web-radio system is made in the size of 50 × 50 mm. Keywords: Beam switching, Adaptive antenna, System-in-chip, ESP32, Web-radio

Robust Adaptive Sliding Mode Consensus of Multiagent Systems with Perturbed Communications and Actuators

Directory of Open Access Journals (Sweden)

Xiao-Zheng Jin

2013-01-01

Full Text Available This paper deals with the asymptotic consensus problem for a class of multiagent systems with time-varying additive actuator faults and perturbed communications. The L2 performance of systems is also considered in the consensus controller designs. The upper and lower bounds of faults and perturbations in actuators and communications and controller gains are assumed to be unknown but can be estimated by designing some indirect adaptive laws. Based on the information from the adaptive estimation mechanism, the distributed robust adaptive sliding mode controllers are constructed to automatically compensate for the effects of faults and perturbations and to achieve any given level of L2 gain attenuation from external disturbance to consensus errors. Through Lyapunov functions and adaptive schemes, the asymptotic consensus of resulting adaptive multiagent system can be achieved with a specified performance criterion in the presence of perturbed communications and actuators. The effectiveness of the proposed design is illustrated via a decoupled longitudinal model of F-18 aircraft.

Developing the evidence base for mainstreaming adaptation of stormwater systems to climate change.

Science.gov (United States)

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.

Algebraic and adaptive learning in neural control systems

Science.gov (United States)

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.

Fault Adaptive Control of Overactuated Systems Using Prognostic Estimation

Data.gov (United States)

National Aeronautics and Space Administration — Most fault adaptive control research addresses the preservation of system stability or functionality in the presence of a specific failure (fault). This paper...

Collaborative Object Framework for Adaptive System Optimization, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — TeamVision proposes that we research the feasibility of incorporating an adaptive object based optimization system into an existing multi-user object oriented...

Enhancing Adaptive Capacity in Food Systems: Learning at Farmers' Markets in Sweden

Directory of Open Access Journals (Sweden)

Rebecka Milestad

2010-09-01

Full Text Available This article examines how local food systems in the form of farmers' markets can enhance adaptive capacity and build social-ecological resilience. It does this by exploring the learning potential among farmers and customers. Learning can enable actors to adapt successfully and thus build adaptive capacity. Three forms of learning are investigated: instrumental, communicative, and emancipatory. These forms of learning constitute the foundation for lasting changes of behaviors. Local food systems are characterized by close links and opportunities for face-to-face interactions between consumers and producers of food, and are also institutions where farmers and customers can express and act upon their ethical values concerning food. However, local food systems are still a marginal phenomenon and cannot be accessed by all consumers. Interviews were held with customers and farmers, and the interactions between farmers and customers were observed at two farmers' markets in Sweden. Customers and farmers were found to learn and adapt to each other due to the opportunities offered by the farmers' markets. We found that farmers and customers learned in the instrumental and communicative domains, but could not confirm emancipatory learning. We concluded that the feedback between customers and farmers offers the potential for learning, which in turn contributes to adaptive capacity. This can be a driving force for building resilience in the food system.

An Architectural Style for Optimizing System Qualities in Adaptive Embedded Systems using Multi-Objective Optimization

NARCIS (Netherlands)

de Roo, Arjan; Sözer, Hasan; Aksit, Mehmet

Customers of today's complex embedded systems demand the optimization of multiple system qualities under varying operational conditions. To be able to influence the system qualities, the system must have parameters that can be adapted. Constraints may be defined on the value of these parameters.

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

Science.gov (United States)

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.

Simple adaptive control system design for a quadrotor with an internal PFC

Energy Technology Data Exchange (ETDEWEB)

Mizumoto, Ikuro; Nakamura, Takuto; Kumon, Makoto; Takagi, Taro [Dept. of Mechanical Systems Engineering, Kumamoto University 2-39-1 Kurokami, Kumamoto, 860-8555 (Japan)

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 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.

Functional aspects of the adaptive immune system in arthritis

NARCIS (Netherlands)

Jansen, D.T.S.L.

2017-01-01

The adaptive immune system is the part of the immune system that is highly specific and generates memory resulting in a fast and specific immune response upon a second infection with the same pathogen. However, when this response is specific for a part of the body itself instead of a pathogen,

Wavelet Adaptive Algorithm and Its Application to MRE Noise Control System

Directory of Open Access Journals (Sweden)

Zhang Yulin

2015-01-01

Full Text Available To address the limitation of conventional adaptive algorithm used for active noise control (ANC system, this paper proposed and studied two adaptive algorithms based on Wavelet. The twos are applied to a noise control system including magnetorheological elastomers (MRE, which is a smart viscoelastic material characterized by a complex modulus dependent on vibration frequency and controllable by external magnetic fields. Simulation results reveal that the Decomposition LMS algorithm (D-LMS and Decomposition and Reconstruction LMS algorithm (DR-LMS based on Wavelet can significantly improve the noise reduction performance of MRE control system compared with traditional LMS algorithm.

Feedback control and adaptive control of the energy resource chaotic system

International Nuclear Information System (INIS)

Sun Mei; Tian Lixin; Jiang Shumin; Xu Jun

2007-01-01

In this paper, the problem of control for the energy resource chaotic system is considered. Two different method of control, feedback control (include linear feedback control, non-autonomous feedback control) and adaptive control methods are used to suppress chaos to unstable equilibrium or unstable periodic orbits. The Routh-Hurwitz criteria and Lyapunov direct method are used to study the conditions of the asymptotic stability of the steady states of the controlled system. The designed adaptive controller is robust with respect to certain class of disturbances in the energy resource chaotic system. Numerical simulations are presented to show these results

Novel adaptive feedback synchronization scheme for a class of chaotic systems with and without parametric uncertainty

International Nuclear Information System (INIS)