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Showing papers in "Applied Artificial Intelligence in 1999"


Journal ArticleDOI
TL;DR: The Open Agent Architecture is structured so as to minimize the effort involved in creating new agents and "wrapping" legacy applications; to encourage the reuse of existing agents; and to allow for dynamism and flexibility in the makeup of agent communities.
Abstract: The Open Agent Architecture (OAA), developed and used for several years at SRI International, makes it possible for software services to be provided through the cooperative efforts of distributed collections of autonomous agents. Communication and cooperation between agents are brokered by one or more facilitators, which are responsible for matching requests, from users and agents, with descriptions of the capabilities of other agents. Thus it is not generally required that a user or agent know the identities, locations, or number of other agents involved in satisfying a request. OAA is structured so as to minimize the effort involved in creating new agents and "wrapping" legacy applications, written in various languages and operating on various platforms; to encourage the reuse of existing agents; and to allow for dynamism and flexibility in the makeup ofagent communities. Distinguishing features of OAA as compared with related work include extreme flexibility in using facilitator-based delegation of com...

727 citations


Journal ArticleDOI
TL;DR: Steve is an animated agent that helps students learn to perform physical, procedural tasks and can also monitor students while they practice tasks, providing assistance when needed.
Abstract: This paper describes Steve , an animated agent that helps students learn to perform physical , procedural tasks . The student and Steve cohabit a three - dimensional , simulated mock - up of the student's work environment . Steve can demonstrate how to perform tasks and can also monitor students while they practice tasks , providing assistance when needed . This paper describes Steve's architecture in detail , including perception , cognition , and motor control . The perception module monitors the state of the virtual world , maintains a coherent representation of it , and provides this information to the cognition and motor control modules . The cognition module interprets its perceptual input , chooses appropriate goals , constructs and executes plans to achieve those goals , and sends out motor commands . The motor control module implements these motor commands , controlling Steve's voice , locomotion , gaze , and gestures , allowing Steve to manipulate objects in the virtual world .

510 citations


Journal ArticleDOI
TL;DR: In this paper, the authors describe results from an experiment of user interaction with autonomous, human-like ( humanoid) conversational agents, and they hypothesize that nonverbal behaviors related to the process of conversation, what they call envelope feedback, is much more important than other feedback, such as emotional expression.
Abstract: In this article we describe results froman experiment of user interaction with autonomous , human - like ( humanoid ) conversational agents . We hypothesize that for embodied conversational agents , nonverbal behaviors related to the process of conversation , what we call envelope feedback, is much more important than other feedback , such as emotional expression . We test this hypothesis by having subjects interact with three autonomous agents , all capable of full - duplex multimodal interaction: able to generate and recognize speech , intonation , facial displays , and gesture . Each agent , however , gave a different kind of feedback: ( 1 ) content - related only , ( 2 ) content + envelope feedback , and ( 3 ) content + emotional . Content-related feedback includes answering questions and executing commands; envelope feedback includes behaviors such as gaze , manual beat gesture , and head movements; emotional feedback includes smiles and looks of puzzlement . Subjects' evaluations of the systemwere c...

412 citations


Journal ArticleDOI
TL;DR: The ZEUS toolkit is a synthesis of established agent technologies with some novel solutions to provide an integrated collaborative agent-building environment that facilitates the rapid development of collaborative agent applications.
Abstract: The multiagent systems approach of knowledge- level cooperation between autonomous agents promises significant benefits to distributed systems engineering, such as enhanced interoperability, scalability, and reconfigurability. However, thus far, because of the innate difficulty of constructing multiagent systems, this promise has been largely unrealized. Hence there is an emerging desire among agent developers to move away from developing point solutions to point problems in favor of developing methodologies and toolkits for building distributed multiagent systems. This philosophy led to the development of the ZEUS Agent Building Toolkit, which facilitates the rapid development of collaborative agent applications through the provision of a library of agent- level components and an environment to support the agent-building process. The ZEUS toolkit is a synthesis of established agent technologies with some novel solutions to provide an integrated collaborative agent-building environment.

314 citations


Journal ArticleDOI
TL;DR: A framework for achieving deictic believability in animated agents is described, which exploits a world model and the evolving explanation plan as it selects and coordinates locomotive, gestural, and speech behaviors.
Abstract: Lifelike animated agents for knowledge - based learning environments can provide timely , customized advice to support students' problem solving . Because of their strong visual presence , they hold significant promise for substantially increasing students' enjoyment of their learning experiences . A key problemposed by lifelike agents that inhabit artificial worlds is deictic believability. In the same manner that humans refer to objects in their environment through judicious combinations of speech , locomotion , and gesture , animated agents should be able to move through their environment and point to and refer to objects appropriately as they provide problem - solving advice . In this paper we describe a framework for achieving deictic believability in animated agents . A deictic behavior planner exploits a world model and the evolving explanation plan as it selects and coordinates locomotive , gestural , and speech behaviors . The resulting behaviors and utterances are believable , and the references...

177 citations


Journal ArticleDOI
TL;DR: This contribution presents a framework for the development of presentation agents, which can be used for a broad range of applications including personalized information delivery from the WWW.
Abstract: Life - like characters are increasingly gaining the attention of researchers and commercial developers of user interfaces . A strong argument in favor of using such characters in the interface is the rich repertoire of options they offer , enabling the emulation of communication styles common in human - human dialog . This contribution presents a framework for the development of presentation agents , which can be used for a broad range of applications including personalized information delivery fromthe WWW .

140 citations


Journal ArticleDOI
TL;DR: To design personalities for social agents, it is necessary to consider the nature of personality and its role in interactions between people and artifacts.
Abstract: Recent research indicates that people respond socially to computers and perceive themas having personalities. Software agents are artifacts that particularly embody those qualities most likely to elicit social responses: fulelling a social role, using language, and exhibiting contingent behavior. People’s disposition to respond socially can be so strong that they may perceive software agents as having a personality, even when none was intended. The following is a discussion about intentionally designing personalities for social agents. To design personalities, it is necessary to consider the nature of personality and its role in interactions between people and artifacts. In addition, a case study of designing a social software agent is presented. The conclusions fromthis experience are summarized as guidelines for future agent developers. Personality is a fundamental linchpin of social relationships. In the context of human interaction, people automatically and unintentionally organize the behavior of their partners into simplifying traits (Uleman et al., 1996), and people tend to agree about which partners are best described by particular traits (Moskowitz, 1988). Beyond categorization, personality shapes the very nature of social relationships, even impacting how satisfying an interaction is for the participants (Dryer & Horowitz, 1997).

120 citations


Journal ArticleDOI
TL;DR: Ymir demonstrates several new ideas in the creation of communicative computer agents, including perceptual integration of multimodal events, distributed planning and decision making, an explicit handling of real time, and perceptuo-motor system layered and motor control with human characteristics.
Abstract: This paper presents a computational model of real - time task - oriented dialog skills . The model , termed Ymir, bridges multimodal perception and multimodal action and supports the creation of autonomous computer characters that afford full - duplex , real - time face - to - face interaction with a human . Ymir has been prototyped in software , and a humanoid created , called Gandalf, capable of fluid multimodal dialog . Ymir demonstrates several new ideas in the creation of communicative computer agents , including perceptual integration of multimodal events, distributed planning and decision making, an explicit handling of real time, and perceptuo-motor system layered and motor control with human characteristics. This paper describes the model's architecture and explains its main elements . Examples of implementation and performance are given , and the architecture's limitations and possibilities are discussed .

92 citations


Journal ArticleDOI
TL;DR: The proposed multiagent system, including its architecture and implementation, is presented and demonstrated through an example integration scenario involving real planning and execution software systems.
Abstract: The production management system used by most manufacturers today consists of disconnected planning and execution processes and lacks the support for interoperability and collaboration needed for enterprise-wide integration. This situation often prevents the manufacturer from fully exploring market opportunities in a timely fashion. To address this problem, we are exploring an agent-based approach to intelligent enterprise integration. In this approach, a set of agents with specialized expertise can be quickly assembled to help with the gathering of relevant information and knowledge, to cooperate with each other and with other parts of the production management system and humans to arrive at timely decisions in dealing with various enterprise scenarios. The proposed multiagent system, including its architecture and implementation, is presented and demonstrated through an example integration scenario involving real planning and execution software systems.

40 citations


Journal ArticleDOI
TL;DR: A multiagent system architecture to increase the value of 24-hour-a day call center service that supports call centers in making appointments with clients on the basis of knowledge of employees and their schedules is described.
Abstract: This article describes a multiagent system architecture to increase the value of 24-hour-a day call center service. This system supports call centers in making appointments with clients on the basis ofknowledge ofemployees and their schedules. Relevant activities are scheduled for employees in preparation ofsuch appointments. The multiagent system architecture is based on principled design, using the compositional development method for multiagent systems DESIRE. To schedule procedures in which more than one employee is involved, each employee is represented by its own personal assistant agent, and a work manager agent coordinates the schedules of the personal assistant agents and clients through the call center. The multiagent system architecture has been applied to the banking domain, in cooperation with and partially funded by the Rabobank.

37 citations


Journal ArticleDOI
TL;DR: The article describes how such a model of personality is implemented in planning with the PRODIGY system and in execution with the RAP system, where behaviors characteristic ofdifferent "helping personality types" are automatically designed and executed in a virtual world.
Abstract: Agents are considered "believable" when viewed by an audience as endowed with behaviors, attitudes, and emotions typical of different personalities. Our work is aimed at realizing believable agents that perform helping behaviors influenced by their personalities, which we represent as different clusters of prioritized goals and preferences over plans for achieving goals. The article describes how such a model of personality is implemented in planning with the PRODIGY system and in execution with the RAP system. Both systems are integrated in a plan-based architecture where behaviors characteristic ofdifferent "helping personality types" are automatically designed and executed in a virtual world. The article also shows examples of the kinds of plan produced by PRODIGY for different personalities and contexts and how such plans are executed by RAP when a helping character interacts with a user in a virtual world.

Journal ArticleDOI
TL;DR: This paper presents an implemented account of multilingual linguistic resources for multilingual text generation that improves significantly on the degree of reuse of resources both across languages and across applications.
Abstract: In this paper we present an implemented account of multilingual linguistic resources for multilingual text generation that improves significantly on the degree of reuse of resources both across languages and across applications. We argue that this is a necessary step for multilingual generation in order to reduce the high cost of constructing linguistic resources and to make natural language generation relevant for a wider range of applications particularly, in this paper, for multilingual software and user interfaces. We begin by contrasting a weak and a strong approach to multilinguality in the state of the art in multilingual text generation. Neither approach has provided sufficient principles for organizing multilingual work. We then introduce our framework , where multilingual variation is included as an intrinsic feature of all levels of representation. We provide an example of multilingual tactical generation using this approach and discuss some of the performance, maintenance, and development issu...

Journal ArticleDOI
TL;DR: This article presents a solution to problems based on a representation of obliged and forbidden behavior in an organizational framework together with an inference method that also decides which obligations to break in conflicting situations.
Abstract: Carrying out distributed business processes over networks is rapidly shifting the nature of application architectures from the simple command and control client-server model to complex peer-to-peer models supporting dynamic patterns of social interaction and behavior among autonomous, proactive, goal oriented agents. Trusting agents to autonomously make decisions and execute actions on behalf of humans, as part of global business processes, requires both understanding and modeling of the social laws that govern collective behavior and a practically useful operationalization of the models into agent programming tools. In this article we present a solution to these problems based on a representation of obliged and forbidden behavior in an organizational framework, together with an inference method that also decides which obligations to break in conflicting situations. These are integrated into an operational, practically useful agent development language that covers the spectrum from the definition of organ...

Journal ArticleDOI
TL;DR: An approach to cross-language text retrieval based on the EuroWordNet (EWN) multilingual semantic database, which turns term weighting and query/document matching into language-independent tasks.
Abstract: We present an approach to cross-language text retrieval based on the EuroWordNet (EWN) multilingual semantic database. EuroWordNet is a multilingual, WordNet-like database with basic semantic relations between words for several European languages (English, Dutch, Spanish, Italian, German, French, Czech, and Estonian). In addition to the relations in WordNet 1.5, EWN includes domain labels, cross-language, and cross-part-of-speech relations, which are directly useful for multilingual information retrieval. In our approach, documents in any language covered by EuroWordNet are indexed in a space of language-independent concepts (the EuroWordNet Inter Lingual Index), thus turning term weighting and query/document matching into language-independent tasks. We report on the results of a number of experiments that measure the potential benefits of the approach and its tolerance to word sense disambiguation errors. In our monolingual experiments, the classical, vector space model for text retrieval is shown to giv...

Journal ArticleDOI
TL;DR: A simulation study of trust and organizational performance, which results indicate that in homogeneous groups, honest groups did better than dishonest groups in terms of trust performance.
Abstract: Executives argue intuitively that trust is critical to effective organizational performance Although articulated as a cognitive/ affective property ofindividuals, the collective effect of events influencing(and being influenced by) trust judgments must certainly impact organizational behavior To begin to explore this, we conducted a simulation study of trust and organizational performance Specifically, we defined a set ofcomputational agents, each with a trust function capable of evaluating the quality ofadvice from the other agents, and rendering judgments on the trustworthiness of the communicating agent As agent judgments impact subsequent choices to accept or to generate communications, organizational performance is influenced We manipulated two agent properties(trustworthiness, benevolence), two organizational variables (group size, group homogeneity/liar-to-honest ratio), and one environmental variable (stable, unstable) Results indicate that in homogeneous groups, honest groups did better tha

Journal ArticleDOI
TL;DR: An architecture and an implemented system for visualizing and controlling distributed multiagent applications that comprises a suite of tools, with each tool providing a different perspective of the application being visualized.
Abstract: Visualizing the behavior of systems with distributed data, control, and process is a notoriously difficult task. Each component in the distributed system has only a local view of the whole setup, and the onus is on the user to integrate, into a coherent whole, the large amounts of limited information they provide. In this article, we describe an architecture and an implemented system for visualizing and controlling distributed multiagent applications. The system comprises a suite of tools, with each tool providing a different perspective of the application being visualized . Each tool interrogates the components of the distributed application, collates the returned information, and presents this information to users in an appropriate manner. This in essence, shifts the burden ofinference from the user to the visualizer. Our visualizer has been evaluated on four distributed multiagent systems: a travel management application, a telecommunications network management application, a business process managemen...

Journal ArticleDOI
TL;DR: This work proposes a simple test for agenthood that can be applied to a putative computational agent and presents a formulation of the test and some variants with a semantics based on sociability.
Abstract: There have been numerous attempts to provide a standardized definition ofa computational agent, but little consensus has emerged. We propose a simple test for agenthood that can be applied to a putative computational agent. Roughly, this test seeks to capture the intuition that an agent is an entity that can function as part ofa multiagent system. The test depends on the observed behavior of the supposed agent and not on the internals of it. We apply the test to some well-known kinds of systems of (supposed) agents and discuss the results. We present a formulation of the test and some variants with a semantics based on sociability. Our treatment of agenthood can thus serve as a methodological basis for evaluating putative agents and agent toolkits.

Journal ArticleDOI
TL;DR: The approach is based on the assumption that it is possible to construct a language independent representation of concepts relevant to the domain, at least for the small well-defined domains typical of IE tasks, allowing multilingual IE to be successfully carried out without requiring full machine translation.
Abstract: The volume of electronic text in different languages, particularly on the World Wide Web, is growing significantly, and the problem of users who are restricted in the number of languages they read obtaining information from this text is becoming more widespread. This article investigates some of the issues involved in achieving multilingual information extraction (IE), describes the approach adopted in the M-LaSIE-II IE system, which addresses these problems, and presents the results of evaluating the approach against a small parallel corpus of English/French newswire texts. The approach is based on the assumption that it is possible to construct a language independent representation of concepts relevant to the domain, at least for the small well-defined domains typical of IE tasks, allowing multilingual IE to be successfully carried out without requiring full machine translation.

Journal ArticleDOI
K. Sekiyama1
TL;DR: This paper presents the self-referential coupling of serf-organizing systems as a design framework of the collective autonomous system and discusses relation between redundancy and optimality in the system structure.
Abstract: This paper describes conception of social robot system as self-organizing system. Distributed autonomous robot system is not autonomous as a group, if the system totally depends on the external intervention to maintain its fundamental function. We discuss the meaning of autonomy for group robot system and a concept of collective autonomy as a fundamental framework for design of the social robotic system. It is firstly discussed the difference between cooperative and self-organizing behavior. After brief review of the classical self-organizing system theory, we present the self-referential coupling of serf-organizing systems as a design framework of the collective autonomous system. Through primitive simulation model, we also discuss relation between redundancy and optimality in the system structure.

Journal ArticleDOI
TL;DR: A model of human actions along with a real - time recognition system for human action recognition is presented and a motion management library is described that solves animation continuity and mixing problems.
Abstract: Most of today's virtual environments are populated with some kind of autonomous life - like agents . Such agents follow a preprogrammed sequence of behaviors that excludes the user as a participating entity in the virtual society . In order to make inhabited virtual reality an attractive place for information exchange and social interaction , we need to equip the autonomous agents with some perception and interpretation skills . In this paper we present one skill: human action recognition . By opposition to human - computer interfaces that focus on speech or hand gestures , we propose a full - body integration of the user . We present a model of human actions along with a real - time recognition system . To cover the bilateral aspect in human - computer interfaces , we also discuss some action response issues . In particular , we describe a motion management library that solves animation continuity and mixing problems . Finally , we illustrate our systemwith two examples and discuss what we have learned .

Journal ArticleDOI
TL;DR: This work argues that it is necessary to consider social conventions in designing believable interaction; they are mechanisms used by conversation partners to coordinate behavior and communication and present design recommendations for how these results can be applied to guide the design of believable interaction.
Abstract: One of the goals of the research area of believable agents is to incorporate those capabilities that can make interaction with agents realistic and believable. We argue that it is necessary to consider social conventions in designing believable interaction; they are mechanisms used by conversation partners to coordinate behavior and communication. As a starting point, we began by identifying essential social conventions that are used to coordinate interaction in the physical world. We performed an empirical study to investigate how these conventions are used by people in virtual environments when they interact; we were interested to see which conventions were used naturally and how they influenced behavior. In our results, we report how these conventions were used to regulate behavior in virtual environments. We present design recommendations for how these results can be applied to guide the design of believable interaction.

Journal ArticleDOI
TL;DR: The proposed method primarily adopted Monte Carlo simulation method, maximum-flow minimum-cut theorem, and optimization techniques to find out the optimal values of reliability indices, such that the optimal reliability design for the system can be achieved.
Abstract: This paper applies network flow method, genetic algorithms, and Monte Carlo simulation to optimal reliability design for a composite electric power system. Genetic algorithms are general purpose optimization techniques based on principles inspired from the biological evolution using three main operations of reproduction, crossover, and mutation, which could locate near optimal solutions in most cases. The proposed method primarily adopted Monte Carlo simulation method, maximum-flow minimum-cut theorem, and optimization techniques to find out the optimal values of reliability indices, such that the optimal reliability design for the system can be achieved. The objective function to be optimized is composed of interruption cost and installation cost. The reliability indices mainly used include expected demand not served (EDNS) and forced outage rate (FOR). An application of the proposed method conducted on an IEEE five-bus test system is presented.

Journal ArticleDOI
TL;DR: A spell checking system that learns user behavior and suggests correct replacements for incorrect words and declares unknown, but correct words to be correct is described.
Abstract: This paper describes a spell checking system that learns user behavior. Based on that insight, the system with high likelihood suggests correct replacements for incorrect words and declares unknown, but correct words to be correct. The system relies on three dictionaries, a so-called user history file, and two logic modules to carry out the learning and spell checking. Tests have proved that the system is very fast and highly reliable. Specifically, the top ranked replacement word for an incorrect word was the correct word 96% of the time. Words that were not in the large dictionary but that nevertheless were correct, for example, persons' names, compound words, and control commands, were declared to be correct 82% of the time. It was never observed that an incorrect word was accepted as correct.

Journal ArticleDOI
TL;DR: The proposed methodology can integrate delayed - arrival data satisfactorily and efficiently interpret multimodal input that contains ambiguity and integrate of delayed arrival of data and elimination of ambiguity in recognition results of each modality.
Abstract: Two requirements should be met in order to develop a practical multimodal interface system , i . e ., ( 1 ) integration of delayed arrival of data and ( 2 ) elimination of ambiguity in recognition results of each modality . This paper presents an efficient and generic methodology for interpretation of multimodal input to satisfy these requirements . The proposed methodology can integrate delayed - arrival data satisfactorily and efficiently interpret multimodal input that contains ambiguity . In the input interpretation the multimodal interpretation process is regarded as hypothetical reasoning , and the control mechanismof interpretation is formalized by applying the assumption - based truth maintenance system ( ATMS ). The proposed method is applied to an interface agent system that accepts multimodal input consisting of voice and direct indication gesture on a touch display . The systemcommunicates to the user through a human - like interface agent's three - dimensional motion image with facial express...

Journal ArticleDOI
TL;DR: In an attempt to implement as language independent a method as possible, the application's methodology features statistical inductive techniques coupled with symbolic processing techniques catering for the analysis of specific language phenomena.
Abstract: This paper describes the application of artificial intelligence methods for the automatic extraction of translation equivalences from bilingual parallel text. In an attempt to implement as language independent a method as possible, the application's methodology features statistical inductive techniques coupled with symbolic processing techniques catering for the analysis of specific language phenomena. The method presupposes parallel texts and identifies translational equivalences at the word or multiword unit level for those cases that such an equivalence holds true. Parallel texts are first aligned at the sentence level and grammatically analyzed. Noun phrase grammars extract noun phrases, and statistical evaluation yields the most coherent multiword units on either side . Translation candidates of word or multiword units are evaluated by a similarity metric defined by the co-occurrence frequency and independent frequencies of the units . The method has been tested on an English - Greek corpus consistin...

Journal ArticleDOI
TL;DR: TransSLIB as discussed by the authors is a system that integrates both new and existing multilingual information tools to provide multilingual access to library catalogues, including functionalities for searching in multiple languages, multilingual presentation of query results, and localization of the user interface.
Abstract: Language barriers present a major problem in the effectiveness of resource sharing and in common access to the resources of libraries. In this paper we present the TRANSLIB system, which consists of an integration of both new and existing multilingual information tools. This system takes full advantage of some AI-based methods in order to provide multilingual access to library catalogues. Its main features include functionalities for searching in multiple languages, multilingual presentation of the query results, and localization of the user interface. TRANSLIB has currently been tested in existing medium-sized bibliographic databases. Evaluation results show a remarkable improvement in the search process and report high user friendliness and easy and low-cost maintenance and upgrade of the system.

Journal ArticleDOI
TL;DR: This VRP system, as used in the NOVA 1 project, aims at providing a training environment for a maritime patrol aircraft (MPA) in an antisubmarine warfare (ASW) mission.
Abstract: In this paper, we introduce the virtual role playing (VRP) concept using intelligent agents. The objective of VRP is to provide training to incomplete teams is by emulating missing human operators. Keystones of this system are the mandatory collaboration between the agents and the homogeneity of the interactions between the intelligent agents and the human operators in order to achieve a common target. This VRP system, as used in the NOVA 1 project, aims at providing a training environment for a maritime patrol aircraft (MPA) in an antisubmarine warfare (ASW) mission.

Journal ArticleDOI
TL;DR: An information theoretic approach for extracting knowledge from databases in the form of inductive rules using Hellinger measure, an entropy function which is utilized as a criteria for selecting rules generated from databases.
Abstract: Systems for inducing classification rules from databases are valuable tools for assisting in the task of knowledge acquisition for expert systems. This paper presents an information theoretic approach for extracting knowledge from databases in the form of inductive rules using Hellinger measure, an entropy function which is utilized as a criteria for selecting rules generated from databases. In order to reduce the complexity of rule generation, the characteristics of Hellinger measure are analyzed and used to prune the search space of hypothesis. The system is implemented and tested on some well-known machine-learning databases.

Journal ArticleDOI
TL;DR: The goal is to show the readers that existing AI methods, although not always mature and near - to - market , can offer much help to support multilinguality in the software industry.
Abstract: In this editorial we briefly discuss issues related to multilinguality in the software industry and highlight areas where AI - based methods , techniques , and tools can be used to support multilinguality We then provide short descriptions of the five papers selected for this special issue Two cover research work on localization of user interfaces and documentation (Boutsis et al and Bateman et al) and are published in this issue The other three cover research work on multilingual text retrieval (Gonzalo et al, Michos et al, and Azzamet al) and are to be published in issue no 7 Our goal is to show the readers that existing AI methods , although not always mature and near - to - market , can offer much help to support multilinguality in the software industry