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380 | 5 | Audio Signal Classification Audio signal classification (ASC) consists of extracting relevant features from a sound, and of using these features to identify into which of a set of classes the sound is most likely to fit. The feature extraction and grouping algorithms used can be quite diverse depending on the classification domain of the application. This paper presents background necessary to understand the general research domain of ASC, including signal processing, spectral analysis, psychoacoustics and auditory scene analysis. Also presented are the basic elements of classification systems. Perceptual and physical features are discussed, as well as clustering algorithms and analysis duration. Neural nets and hidden Markov models are discussed as they relate to ASC. These techniques are presented with an overview of the current state of the ASC research literature. 1 Introduction This paper will present a review of the state of the current research literature pertaining to audio signal classifiation (ASC). ... | [
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381 | 3 | Scalable Processing of Read-Only Transactions in Broadcast Push Recently, push-based delivery has attracted considerable attention as a means of disseminating information to large client populations in both wired and wireless settings. In this paper, we address the problem of ensuring the consistency and currency of client read-only transactions in the presence of updates. To this end, additional control information is broadcast. A suite of methods is proposed that vary in the complexity and volume of the control information transmitted and subsequently differ in response times, degrees of concurrency, and space and processing overheads. The proposed methods are combined with caching to improve query latency. The relative advantages of each method are demonstrated through both simulation results and qualitative arguments. Read-only transactions are processed locally at the client without contacting the server and thus the proposed approaches are scalable, i.e., their performance is independent of the number of clients. 1. Introduction In traditio... | [
768,
800,
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382 | 3 | Interaction between Path and Type Constraints XML [7], which is emerging as an important standard for data exchange on the World-Wide Web, highlights the importance of semistructured data. Although the XML standard itself does not require any schema or type system, a number of proposals [6, 17, 19] have been developed that roughly correspond to data definition languages. These allow one to constrain the structure of XML data by imposing a schema on it. These and other proposals also advocate the need for integrity constraints, another form of constraints that should, for example, be capable of expressing inclusion constraints and inverse relationships. The latter have recently been studied as path constraints in the context of semistructured data [4, 9]. It is likely that future XML proposals will involve both forms of constraints, and it is therefore appropriate to understand the interaction between them. This paper investigates that interaction. In particular it studies constraint implication problems, which are important both i... | [
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383 | 3 | Using Constraint Satisfaction for View Update Translation View update is the problem of translating update requests against a view into update requests against the base data. In this paper, we present a novel approach to this problem in relational databases. Using conditional tables to represent relational views, we translate a view update problem into a disjunction of a number of constraint satisfaction problems (CSPs). Solutions to the CSPs correspond to possible translations of the view update. Semantic information to resolve ambiguity can be handled as additional constraints in the CSPs. This approach enables us to apply the rich results of the CSP research to analyze and solve an important problem in database management. | [] | Train |
384 | 4 | The State of the Art in Distributed and Dependable Computing This report is dedicated to the memory of Henrique Fonseca | [
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385 | 2 | An Open Electronic Marketplace through Agent-based Workflows: MOPPET We propose an electronic marketplace architecture, called MOPPET, where the commerce processes in the marketplace are modeled as adaptable agent-based workflows. The higher level of abstraction provided by the workflow technology makes the customization of electronic commerce processes for different users possible. Agent-based implementation, on the other hand, provides for a highly reusable component-based workflow architecture as well as negotiation ability and the capability to adapt to dynamic changes in the environment. Agent communication is handled through Knowledge Query and Manipulation Language (KQML). A workflow-based architecture also makes it possible for complete modeling of electronic commerce processes by allowing involved parties to be able to invoke already existing applications or to define new tasks and to restructure the control and data flow among the tasks to create custom built process definitions. In the proposed architecture all data exchanges are realized through Extensible Markup Language (XML) providing uniformity, simplicity and a highly open and interoperable architecture. Metadata of activities are expressed through Resource Description Framework (RDF). Common Business Library (CBL) is used for achieving interoperability across business domains and domain specific Document Type Definitions (DTDs) are used for vertical industries. We provide our own specifications for missing DTDs to be replaced by the original specifications when they become available. | [
4,
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386 | 4 | Interpretation of Shape-related Iconic Gestures in Virtual Environments The interpretation of iconic gestures in spatial domains is a promising idea to improve the communicative capabilities of human-computer interfaces. So far, approaches towards gesture recognition focused mainly on deictic and emblematic gestures. Iconics, viewed as iconic signs in the sense of Peirce, are different from deictics and emblems, for their relation to the referent is based on similarity. In the work reported here, the breakdown of the complex notion of similarity provides the key idea towards a computational model of gesture semantics for iconic gestures. Based on an empirical study,we describe first steps towards a recognition model for shape-related iconic gestures and its implementation in a prototype gesture recognition system. Observations are focused on spatial concepts and their relation to features of iconic gestural expressions. The recognition model is based on a graphmatching method which compares the decomposed geometrical structures of gesture and object. | [
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387 | 2 | Agora: Enhancing Group Awareness and Collaboration in Floristic Digital Libraries . Digital libraries can be regarded as virtual spaces in which collaborative scholarly research can be conducted. Floristic digital libraries provide such collaboration spaces for scientists working on solutions for Earth's biodiversity problems. However, group awareness and collaboration are not easily achieved in an increasingly distributed environment such as the virtual space in which digital library users (particularly botanists and biologists) do their work. We describe an environment that enables group awareness, communication, and collaboration among users in a globally accessible floristic digital library. This is achieved by extending existing library facilities with recommendation and alerting services, as well as various communication interfaces. Keywords: Recommendation services, group awareness, agents, floristic digital libraries. 1. Introduction Digital libraries comprise highly complex and dynamic information spaces on top of which a variety of services are provide... | [
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388 | 4 | Supporting Workspace Awareness in Distance Learning Environments: Issues and Experiences in the Development of a Collaborative Learning System In recent years, we have witnessed an enormous growth in networks and related technologies. Course materials are increasingly published on web servers, and students are encouraged to access these at leisure. Distance learning via the WWW shifted the education paradigm from teacher-centered instruction to user-centered collaborative learning. Systems that allow users to learn collaboratively are increasingly interesting to scientific communities and learning organizations. We initially designed and prototyped a collaborative system to support collaborative learning over the Internet. A usability study of the first prototype revealed the importance of awareness information. Our review of three wellknown collaborative systems finds that such systems today also lack support for awareness information, especially workspace awareness. We then consider various types of awareness in collaborative learning situations and set out the design requirements of our system. From these requirements, we have designed and prototyped several awareness widgets for a typical collaborative tool: the shared electronic whiteboard. These widgets help learners maintain awareness of other learners' interactions with the shared workspace. | [
1989
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389 | 3 | A Formal Approach to Detecting Security Flaws in Object-Oriented Databases This paper adopts the method-based authorization model and assumes the following database management policies. Let (m, (c 1 ,c 2 , ...,c n )) be in an authorization for a user u. | [
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390 | 2 | A Maximum Entropy Language Model Integrating N-Grams And Topic Dependencies For Conversational Speech Recognition A compact language model which incorporates local dependencies in the form of N-grams and long distance dependencies through dynamic topic conditional constraints is presented. These constraints are integrated using the maximum entropy principle. Issues in assigning a topic to a test utterance are investigated. Recognition results on the Switchboard corpus are presented showing that with a very small increase in the number of model parameters, reduction in word error rate and language model perplexity are achieved over trigram models. Some analysis follows, demonstrating that the gains are even larger on content-bearing words. The results are compared with those obtained by interpolating topicindependent and topic-specific N-gram models. The framework presented here extends easily to incorporate other forms of statistical dependencies such as syntactic word-pair relationships or hierarchical topic constraints. 1. INTRODUCTION Language modeling is a crucial component of systems that c... | [
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391 | 0 | How to Monitor and Control Resource Usage in Mobile Agent Systems The Mobile Agent technology has already shown its advantages, but at the same time has already remarked new problems currently limiting its diffusion in commercial environments. A key issue is to control the operations that foreign mobile agents are authorized to perform on hosting execution environments. It is necessary not only to rule the MA access to resources but also to control resource usage of admitted agents at execution time, for instance to protect against possible denial-of-service attacks. The paper presents a solution framework for the on-line monitoring and control of Java-based MA platforms. In particular, it describes the design and implementation of MAPI, an on-line monitoring component that we have integrated within the SOMA system. The paper shows how to use MAPI as the building block of a distributed monitoring tool that gives application- and kernel-level information about the state of mobile agents and their resource usage, thus enabling the enforcement of management policies on MA resource consumption. 1. | [
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392 | 3 | Optimizing Branching Path Expressions Path expressions form the basis of most query languages for semistructured data and XML, specifying traversals through graph-based data. We consider the query optimization problem for path expressions that "branch," or specify traversals through two or more related subgraphs; such expressions are common in nontrivial queries over XML data. Searching the entire space of query plans for branching path expressions is generally infeasible, so we introduce several heuristic algorithms and postoptimizations that generate query plans for branching path expressions. All of our algorithms have been implemented in the Lore database system for XML, and we report experimental results over a variety of database and query shapes. We compare optimization and execution times across our suite of algorithms and post-optimizations, and for small queries we compare against the optimal plan produced by an exhaustive search of the plan space. 1 Introduction Wo r k i n semistructured data [Abi97, ... | [
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393 | 4 | Pedagogical Content Knowledge in a Tutorial Dialogue System to Support Self-Explanation We are engaged in a research project to create a tutorial dialogue system that helps students learn through self-explanation. Our current prototype is able to analyze students' general explanations of their problem-solving steps, stated in their own words, recognize the types of omissions that we often see in these explanations, and provide feedback. Our approach to architectural tradeoffs is to equip the system with a sophisticated NLU component but to keep dialogue management simple. The system has a knowledge-based NLU component, which performed with 81% accuracy in a preliminary evaluation study. The system's approach to dialogue management can be characterised as "classify and react". In each dialogue cycle, the system classifies the student input with respect to a hierarchy of explanation categories that represent common ways of stating complete or incomplete explanations of geometry rules. The system then provides feedback based on that classification. We consider what extensions are necessary or desirable in order to make the dialogues more robust. | [
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394 | 4 | CAVEStudy: an Infrastructure for Computational Steering in Virtual Reality Environments We present the CAVEStudy system that enables scientists to interactively steer a simulation from a virtual reality (VR) environment. No modification to the source code is necessary. CAVEStudy allows interactive and immersive analysis of a simulation running on a remote computer. Using a high-level description of the simulation, the system generates the communication layer (based on CAVERNSoft) needed to control the execution and to gather data at runtime. We describe three case-studies implemented with CAVEStudy: soccer simulation, diode laser simulation, and molecular dynamics. 1. Introduction High-speed networks and high performance graphics open opportunities for completely new types of applications. As a result, the world of scientific computing is moving away from the batch-oriented management to interactive programs. Also, virtual reality (VR) systems are now commercially available, but so far scientists mainly use them for off-line visualization of data sets produced by a simu... | [
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395 | 0 | Speech Acts for Dialogue Agents this paper by the U.S. Army Research Office under contract/grant number DAAH 04 95 10628 and the U.S. National Science Foundation under grant IRI9311988. Some of the work described above was developed in collaboration with James Allen and supported by ONR/DARPA under grant number N00014-92J -1512, by ONR under research grant number N00014-90-J-1811, and by NSF under grant number IRI-9003841. | [
774,
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396 | 3 | On the Extension of UML with Use Case Maps Concepts . Descriptions of reactive systems focus heavily on behavioral aspects, often in terms of scenarios. To cope with the increasing complexity of services provided by these systems, behavioral aspects need to be handled early in the design process with flexible and concise notations as well as expressive concepts. UML offers different notations and concepts that can help describe such services. However, several necessary concepts appear to be absent from UML, but present in the Use Case Map (UCM) scenario notation. In particular, Use Case Maps allow scenarios to be mapped to different architectures composed of various component types. The notation supports structured and incremental development of complex scenarios at a high level of abstraction, as well as their integration. UCMs specify variations of run-time behavior and scenario structures through sub-maps "pluggable" into placeholders called stubs. This paper presents how UCM concepts could be used to extend the semantics... | [
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397 | 3 | Repeating History beyond ARIES In this paper, I describe first the background behind the development of the original ARIES recovery method, and its significant impact on the commercial world and the research community. Next, I provide a brief introduction to the various concurrency control and recovery methods in the ARIES family of algorithms. Subsequently, I discuss some of the recent developments affecting the transaction management area and what these mean for the future. In ARIES, the concept of repeating history turned out to be an important paradigm. As I examine where transaction management is headed in the world of the internet, I observe history repeating itself in the sense of requirements that used to be considered significant in the mainframe world (e.g., performance, availability and reliability) now becoming important requirements of the broader information technology community as well. 1. Introduction Transaction management is one of the most important functionalities provided by a... | [
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398 | 1 | Generating Accurate Rule Sets Without Global Optimization The two dominant schemes for rule-learning, C4.5 and RIPPER, both operate in two stages. First they induce an initial rule set and then they refine it using a rather complex optimization stage that discards (C4.5) or adjusts (RIPPER) individual rules to make them work better together. In contrast, this paper shows how good rule sets can be learned one rule at a time, without any need for global optimization. We present an algorithm for inferring rules by repeatedly generating partial decision trees, thus combining the two major paradigms for rule generation—creating rules from decision trees and the separate-and-conquer rule-learning technique. The algorithm is straightforward and elegant: despite this, experiments on standard datasets show that it produces rule sets that are as accurate as and of similar size to those generated by C4.5, and more accurate than RIPPER’s. Moreover, it operates efficiently, and because it avoids postprocessing, does not suffer the extremely slow performance on pathological example sets for which the C4.5 method has been criticized. | [
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399 | 2 | Latent Semantic Indexing by Self-Organizing Map An important problem for the information retrieval from spoken documents is how to extract those relevant documents which are poorly decoded by the speech recognizer. In this paper we propose a stochastic index for the documents based on the Latent Semantic Analysis (LSA) of the decoded document contents. The original LSA approach uses Singular Value Decomposition to reduce the dimensionality of the documents. As an alternative, we propose a computationally more feasible solution using Random Mapping (RM) and Self-Organizing Maps (SOM). The motivation for clustering the documents by SOM is to reduce the effect of recognition errors and to extract new characteristic index terms. Experimental indexing results are presented using relevance judgments for the retrieval results of test queries and using a document perplexity defined in this paper to measure the power of the index models. 1. INTRODUCTION In this paper we present methods for indexing speech data which has been automatically t... | [
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400 | 0 | Desiderata for Agent Oriented Programming Languages Multiagent system designers need programming languages in order to develop agents and multiagent systems. Current approaches consist to use classical programming languages like C or C++ and above all Java which is the most preferred language by agent community thanks to its rich library of functions. The aim of Java is not to design multiagent systems so it does not encompass multiagent features. The aim of this paper is to present a set of characteristics which could be present in an agent-oriented programming language. This paper also describes what kind of multiagent systems could be developed with this set of characteristics. | [
1049,
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401 | 1 | Primitive-Based Movement Classification for Humanoid Imitation . Motor control is a complex problem and imitation is a powerful mechanism for acquiring new motor skills. In this paper, we describe perceptuo-motor primitives, a biologically-inspired notion for a basis set of perceptual and motor routines. Primitives serve as a vocabulary for classifying and imitating observed human movements, and are derived from the imitator's motor repertoire. We describe a model of imitation based on such primitives and demonstrate the feasibility of the model in a constrained implementation. We present approximate motion reconstruction generated from visually captured data of typically imitated tasks taken from aerobics, dancing, and athletics. 1 Introduction Imitation is a powerful mechanism for acquiring new skills. It involves an intricate interaction between perceptual and motor mechanisms, both of which are complex in themselves. Research into vision and motor control has explored the role of "subroutines", schemas [1], and other variants based on ... | [
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402 | 1 | Learning to Refine Case Libraries: Initial Results . Conversational case-based reasoning (CBR) systems, which incrementally extract a query description through a user-directed conversation, are advertised for their ease of use. However, designing large case libraries that have good performance (i.e., precision and querying efficiency) is difficult. CBR vendors provide guidelines for designing these libraries manually, but the guidelines are difficult to apply. We describe an automated inductive approach that revises conversational case libraries to increase their conformance with design guidelines. Revision increased performance on three conversational case libraries. 1 Introduction In the context of the ECML-97 Workshop entitled Case-Based Learning: Beyond Classification of Feature Vectors, this paper's contribution focuses on using machine learning methods to assist in the design of case libraries. These libraries are designed for solution retrieval rather than classification tasks, and each case might contain a unique solution. Cas... | [
2228,
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403 | 0 | Specifying Agents with UML in Robotic Soccer The use of agents and multiagent systems is widespread in computer science nowadays. Thus the need for methods to specify agents in a clear and simple manner arises. In this paper we propose an approach to specifying agents with the help of UML statecharts. Agents are specified on different levels of abstraction. In addition a method for specifying multiagent plans with explicit cooperation is shown. As an example domain we chose robotic soccer, which lays the basis of the annual RoboCup competitions. Robotic soccer is an ideal testbed for research in the fields of robotics and multiagent systems. In the RoboCup Simulation League the research focus is laid on agents and multiagent systems, and we will demonstrate our approach by using examples from this domain. Keywords: Multiagent Systems, Unified Modeling Language (UML), Specification, RoboCup, Robotic Soccer 1 | [
780,
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404 | 0 | Agents in Annotated Worlds Virtual worlds offer great potential as environments for education, entertainment, and collaborative work. Agents that function effectively in heterogeneous virtual spaces must have the ability to acquire new behaviors and useful semantic information from those contexts. The human-computer interaction literature discusses how to construct spaces and objects that provide "knowledge in the world" that aids human beings to perform these tasks. In this paper, we describe how to build comparable annotated environments containing explanations of the purpose and uses of spaces and activities that allow agents quickly to become intelligent actors in those spaces. Examples are provided from our application domain, believable agents acting as inhabitants and guides in a children's exploratory world. Keywords: believability, human-like qualities of synthetic agents, synthetic agents 1. Introduction Today's virtual environments present opportunities for simulation and interaction involving ma... | [
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405 | 1 | Unsupervised Learning of Models for Recognition Abstract. We present a method to learn object class models from unlabeled and unsegmented cluttered scenes for the purpose of visual object recognition. We focus on a particular type of model where objects are represented as flexible constellations of rigid parts (features). The variability within a class is represented by a joint probability density function (pdf) on the shape of the constellation and the output of part detectors. In a first stage, the method automatically identifies distinctive parts in the training set by applying a clustering algorithm to patterns selected by an interest operator. It then learns the statistical shape model using expectation maximization. The method achieves very good classification results on human faces and rear views of cars. 1 Introduction and Related Work We are interested in the problem of recognizing members of object classes, where we define an object class as a collection of objects which share characteristic features or parts that are visually similar and occur in similar spatial configurations. When building models for object classes of this type, one is faced with three problems (see Fig. 1). | [
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406 | 4 | Value-added Mediation in Large-Scale Information Systems Many information-processing tasks can be part of multiple customer applications, as summarizing stock prices, integrating catolog information from several companies in the same line of business, predicting the weather, and checking on transportation resources. We assign such sharable services to an active middleware layer, interposed between clients and servers. We define domain-specific mediator modules to populate this layer. Such mediating services must be of value to the customers, so that it will benefit their client applications to access mediators rather than the server sources directly. Several categories of value can be considered: improvement in access and coverage, improvement of content, and delegation of maintenance. We will define criteria for mediating modules: ownership by party who assumes responsibility for the rseults of the services, domain-specificity to delimit the scope of such a responsibility, and, of course, conformance with interface standards that ... | [
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407 | 2 | Information Extraction via Heuristics for a Movie Showtime Query System Semantic interpretation for limited-domain spoken dialogue systems often amounts to extracting information from utterances. For a system that provides movie showtime information, queries are classified along four dimensions: question type, and movie titles, towns and theaters that were mentioned. Simple heuristics suffice for constructing highly accurate classifiers for the latter three attributes; classifiers for the question type attribute are induced from data using features tailored to spoken language phenomena. Since separate classifiers are used for the four attributes, which are not independent, certain errors can be detected and corrected, thus increasing robustness. 1. | [
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408 | 5 | Geometric Foundations for Interval-Based Probabilities The need to reason with imprecise probabilities arises in a wealth of situations ranging from pooling of knowledge from multiple experts to abstraction-based probabilistic planning. Researchers have typically represented imprecise probabilities using intervals and have developed a wide array of different techniques to suit their particular requirements. In this paper we provide an analysis of some of the central issues in representing and reasoning with interval probabilities. At the focus of our analysis is the probability cross-product operator and its interval generalization, the cc-operator. We perform an extensive study of these operators relative to manipulation of sets of probability distributtions. This study provides insight into the sources of the strengths and weaknesses of various approaches to handling probability intervals. We demonstrate the application of our results to the problems of inference in interval Bayesian networks and projection and evaluation of abstract pro... | [] | Train |
409 | 2 | Authoring and Annotation of Web Pages in CREAM Richly interlinked, machine-understandable data constitute the basis for the Semantic Web. We provide a framework, CREAM, that allows for creation of metadata. While the annotation mode of CREAM allows to create metadata for existing web pages, the authoring mode lets authors create metadata --- almost for free --- while putting together the content of a page. As a particularity of our framework, CREAM allows to create relational metadata, i.e. metadata that instantiate interrelated definitions of classes in a domain ontology rather than a comparatively rigid template-like schema as Dublin Core. We discuss some of the requirements one has to meet when developing such an ontology-based framework, e.g. the integration of a metadata crawler, inference services, document management and a meta-ontology, and describe its implementation, viz. Ont-O-Mat a component-based, ontology-driven Web page authoring and annotation tool. | [
338,
512,
1484,
2003,
2284,
2418,
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410 | 1 | Face Detection Using Mixtures of Linear Subspaces We present two methods using mixtures of linear subspaces for face detection in gray level images. One method uses a mixture of factor analyzers to concurrently perform clustering and, within each cluster, perform local dimensionality reduction. The parameters of the mixture model are estimated using an EM algorithm. A face is detected if the probability of an input sample is above a predefined threshold. The other mixture of subspaces method uses Kohonen’s self-organizing map for clustering and Fisher Linear Discriminant to find the optimal projection for pattern classification, and a Gaussian distribution to model the class-conditional density function of the projected samples for each class. The parameters of the class-conditional density functions are maximum likelihood estimates and the decision rule is also based on maximum likelihood. A wide range of face images including ones in different poses, with different expressions and under different lighting conditions are used as the training set to capture the variations of human faces. Our methods have been tested on three sets of 225 images which contain 871 faces. Experimental results on the first two datasets show that our methods perform as well as the best methods in the literature, yet have fewer false detects. 1 | [
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411 | 5 | Probabilistic Frame-Based Systems Two of the most important threads of work in knowledge representation today are frame-based representation systems (FRS's) and Bayesian networks (BNs). FRS's provide an excellent representation for the organizational structure of large complex domains, but their applicability is limited because of their inability to deal with uncertainty and noise. BNs provide an intuitive and coherent probabilistic representation of our uncertainty, but are very limited in their ability to handle complex structured domains. In this paper, we provide a language that cleanly integrates these approaches, preserving the advantages of both. Our approach allows us to provide natural and compact definitions of probability models for a class, in a way that is local to the class frame. These models can be instantiated for any set of interconnected instances, resulting in a coherent probability distribution over the instance properties. Our language also allows us to represent important types of uncertainty tha... | [
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412 | 4 | Towards Real-Scale Business Transaction Workflow Modelling While the specification languages of workflow management systems focus on process execution semantics, the successful development of workflows relies on a fuller conceptualisation of business processing, including process semantics. For this, a wellspring of modelling techniques, paradigms and informal-formal method extensions which address the analysis of organisational processing structures (enterprise modelling) and communication (based on speech-act theory), is available. However, the characterisations - indeed the cognition - of workflows still appears coarse. In this paper, we provide the complementary, empirical insight of a real-scale business transaction workflow. The development of the workflow model follows a set of principles which we believe address workflow modelling suitability. Through the principles, advanced considerations including asynchronous as well as synchronous messaging, temporal constraints and a service-oriented perspective are motivated. By illust... | [
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413 | 2 | Web Genre Visualization Web users vary widely in terms of their expertise on the topics for which they search, the amount of detail they seek, etc. Unfortunately, today's one-size-fits-all Web search services do not cater to such individual preferences. For example, it is difficult to query for documents that give extensive detail but assume modest prior expertise. We describe how shallow text classification techniques can be used to sort the documents returned by Web search services according to genre dimensions such as level of expertise and amount of detail, and propose a simple visualization interface that helps users rapidly find appropriate documents. (Keywords: document genre; information retrieval, visualisation, text classification, shallow linguistic processing) Motivation Consider two users seeking information about Pearson' correlation coefficient. Alice is writing a data-analysis program and needs a web page to remind her of the equations. Bob, a teacher, wants to point his pupils to an overview that isn't bogged down in equations. | [
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414 | 4 | Principles of Mixed-Initiative User Interfaces Recent debate has centered on the relative promise of focusing user-interface research on developing new metaphors and tools that enhance users' abilities to directly manipulate objects versus directing effort toward developing interface agents that provide automation. In this paper, we review principles that show promise for allowing engineers to enhance human---computer interaction through an elegant coupling of automated services with direct manipulation. Key ideas will be highlighted in terms of the LookOut system for scheduling and meeting management. Keywords Intelligent agents, direct manipulation, user modeling, probability, decision theory, UI design INTRODUCTION There has been debate among researchers about where great opportunities lay for innovating in the realm of human--- computer interaction [10]. One group of researchers has expressed enthusiasm for the development and application of new kinds of automated services, often referred to as interface "agents." The effo... | [
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415 | 3 | Achieving Workflow Adaptability by means of Reflection Belief in the importance of business processes has triggered considerable interest in the workflow systems that automate these processes. However, of the two competing management philosophies that promulgate business processes, Business Process Reengineering proposes radical change, whereas Continuous Process Improvement places much greater emphasis on adaptability. The former school is somewhat discredited, whereas the latter school seems more likely to endure, thus making the flexibility and evolution of workflows an issue of increasing importance. In this paper, we present a programmable object-oriented metalevel framework which aims to reveal the processes of assembling and coordinating the tasks that make up business processes. This is achieved by isolating four key facets -- state, behaviour, location and coordination. In particular, we open up the general process of task coordination and specification, allowing for extensions in a planned way. By suitable manipulation of coordin... | [
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416 | 3 | Managing Historical Semistructured Data this article appeared in [6]. | [
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417 | 5 | Optimal Anytime Search For Constrained Nonlinear Programming In this thesis, we study optimal anytime stochastic search algorithms (SSAs) for solving general constrained nonlinear programming problems (NLPs) in discrete, continuous and mixed-integer space. The algorithms are general in the sense that they do not assume differentiability or convexity of functions. Based on the search algorithms, we develop the theory of SSAs and propose optimal SSAs with iterative deepening in order to minimize their expected search time. Based on the optimal SSAs, we then develop optimal anytime SSAs that generate improved solutions as more search time is allowed. Our SSAs for solving general constrained NLPs are based on the theory of discrete con-strained optimization using Lagrange multipliers that shows the equivalence between the set of constrained local minima (CLMdn) and the set of discrete-neighborhood saddle points (SPdn). To implement this theory, we propose a general procedural framework for locating an SPdn. By incorporating genetic algorithms in the framework, we evaluate new constrained search algorithms: constrained genetic algorithm (CGA) and combined constrained simulated annealing and genetic algorithm (CSAGA). | [
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418 | 3 | Design and Implementation of the OLOG Deductive Object-Oriented Database Management System . OLOG is a novel deductive database system for advanced intelligent information system applications. It directly supports eective storage, ecient access and inference of large amount of persistent data with complex structures. It provides a SQL-like data denition language and data manipulation language, and a declarative rule-based query language. It combines the best of the deductive, object-oriented, and objectrelational approaches in a uniform framework. This paper describes the design and implementation of the OLOG system. 1 Introduction Deductive, object-oriented, and object-relational databases are three important extensions of the traditional relational database technology. Deductive databases stem from the integration of logic programming and relational databases. It oers representational and operational uniformity, reasoning capabilities, recursion, declarative querying, ecient secondary storage access, etc. However, deductive databases based on relational databas... | [
464,
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419 | 1 | Formalising the Knowledge Content of Case Memory Systems Discussions of case-based reasoning often reflect an implicit assumption that a case memory system will become better informed, i.e. will increase in knowledge, as more cases are added to the case-base. This paper considers formalisations of this `knowledge content' which are a necessary preliminary to more rigourous analysis of the performance of case-based reasoning systems. In particular we are interested in modelling the learning aspects of case-based reasoning in order to study how the performance of a case-based reasoning system changes as it accumlates problem-solving experience. The current paper presents a `case-base semantics' which generalises recent formalisations of case-based classification. Within this framework, the paper explores various issues in assuring that these sematics are well-defined, and illustrates how the knowledge content of the case memory system can be seen to reside in both the chosen similarity measure and in the cases of the case-base. 1 Introduction ... | [
1284,
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] | Train |
420 | 3 | Time Series Classification by Boosting Interval Based Literals A supervised classification method for temporal series, even multivariate, is presented. It is based on boosting very simple classifiers: clauses with one literal in the body. The background predicates are based on temporal intervals. Two types of predicates are used: i) relative predicates, such as "increases" and "stays", and ii) region predicates, such as "always" and "sometime", which operate over regions in the dominion of the variable. Experiments on di#erent data sets, several of them obtained from the UCI repositories, show that the proposed method is highly competitive with previous approaches. Keywords: time series classification, interval based literals, boosting, machine learning. 1 | [
1706
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421 | 4 | Lifelike Gesture Synthesis and Timing for Conversational Agents Besides the inclusion of gesture recognition devices as an intuitive input modality, the synthesis of lifelike gesture is finding growing attention in human-computer interface research. In particular, the generation of synthetic gesture in connection with text-to-speech systems is one of the goals for embodied conversational agents which have become a new paradigm for the study of gesture and for human-computer interface [1]. Embodied conversational agents are computer-generated characters that demonstrate similar properties as humans in face-to-face conversation, including the ability to produce and respond to verbal and nonverbal communication. They may represent the computer in an interaction with a human or represent their human users as "avatars " in a computational environment. In this context, this contribution focusses on an approach for synthesizing lifelike gestures for an articulated virtual agent, with particular emphasis on how to achieve temporal coordination with external information such as the signal generated by a text-to-speech system. The context of this research is the conception of an "articulated communicator " that conducts multimodal dialogue with a human partner in cooperating on a construction task. Gesture production and performance in humans is a complex and multi-stage process. | [
646,
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] | Train |
422 | 4 | LegORB and Ubiquitous CORBA The increasing popularity of ubiquitous computing and the new approaches for low-consumption, shortrange wireless connectivity will enable a future with hundreds of heterogeneous devices interconnected to achieve a common task. However, communication among those network enabled heterogeneous devices requires standard protocols and well defined interfaces. While existing middleware architectures already offer standard mechanisms (DCOM, CORBA, JINI), they are, in most of the cases, not suitable for most of the heterogeneous devices. The resources required by those middleware solutions normally exceed the computational limits of the heterogeneous devices We present in this paper a minimalist component-based Object Request Broker (ORB) that can be dynamically reconfigured and requires, for the smallest configuration, 6Kb of memory. Introduction The incoming ubiquitous computing trend allows the existence of collections of network-enabled devices attached to rooms, people and buildings.... | [
837
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423 | 1 | Using Case-Based Reasoning to Acquire User Scheduling Preferences that Change over Time Production/Manufacturing scheduling typically involves the acquisition of user optimization preferences. The ill-structuredness of both the problem space and the desired objectives make practical scheduling problems difficult to formalize and costly to solve, especially when problem configurations and user optimization preferences change over time. This paper advocates an incremental revision framework for improving schedule quality and incorporating user dynamically changing preferences through Case-Based Reasoning. Our implemented system, called CABINS, records situation-dependent tradeoffs and consequences that result from schedule revision to guide schedule improvement. The preliminary experimental results show that CABINS is able to effectively capture both user static and dynamic preferences which are not known to the system and only exist implicitly in a extensional manner in the case base. 1 Introduction Scheduling deals with allocation of a limited set of resources to a nu... | [
1057
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424 | 0 | The Adaptive Agent Architecture: Achieving FaultTolerance Using Persistent Broker Teams Brokers are used in many multi-agent systems for locating agents, for routing and sharing information, for managing the system, and for legal purposes, as independent third parties. However, these multi-agent systems can be incapacitated and rendered non-functional when the brokers become inaccessible due to failures such as machine crashes, network breakdowns, and process failures that can occur in any distributed software system. We propose that the theory of teamwork can be used to create robust brokered architectures that can recover from broker failures, and we present the Adaptive Agent Architecture (AAA) to show the feasibility of this approach. The AAA brokers form a team with a joint commitment to serve any agent that registers with the broker team as long as the agent remains registered with the team. This commitment enables the brokers to substitute for each other when needed. A multiagent system based on the AAA can continue to work despite broker failures as long... | [
438,
672,
1724,
2301,
2314,
2955
] | Validation |
425 | 3 | Incremental and Interactive Sequence Mining The discovery of frequent sequences in temporal databases is an important data mining problem. Most current work assumes that the database is static, and a database update requires rediscovering all the patterns by scanning the entire old and new database. In this paper, we propose novel techniques for maintaining sequences in the presence of a) database updates, and b) user interaction (e.g. modifying mining parameters). This is a very challenging task, since such updates can invalidate existing sequences or introduce new ones. In both the above scenarios, we avoid re-executing the algorithm on the entire dataset, thereby reducing execution time. Experimental results confirm that our approach results in substantial performance gains. 1 Introduction Sequence mining is an important data mining task, where one attempts to discover frequent sequences over time, of attribute sets in large databases. This problem was originally motivated by applications in the retailing industry, including... | [
3079
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426 | 2 | On the Learnability and Design of Output Codes for Multiclass Problems . Output coding is a general framework for solving multiclass categorization problems. Previous research on output codes has focused on building multiclass machines given predefined output codes. In this paper we discuss for the first time the problem of designing output codes for multiclass problems. For the design problem of discrete codes, which have been used extensively in previous works, we present mostly negative results. We then introduce the notion of continuous codes and cast the design problem of continuous codes as a constrained optimization problem. We describe three optimization problems corresponding to three different norms of the code matrix. Interestingly, for the l 2 norm our formalism results in a quadratic program whose dual does not depend on the length of the code. A special case of our formalism provides a multiclass scheme for building support vector machines which can be solved efficiently. We give a time and space efficient algorithm for solving the quadratic program. We describe preliminary experiments with synthetic data show that our algorithm is often two orders of magnitude faster than standard quadratic programming packages. We conclude with the generalization properties of the algorithm. Keywords: Multiclass categorization,output coding, SVM 1. | [
993
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427 | 4 | Information Seeking as Socially Situated Activity this paper, we discuss implications of situatedness in its social and cultural meaning in the context of information seeking support. We proceed as follows. First, we discuss some of the varying meanings of the term \situated". Then, we outline how we interpret \accounting for situatedness" in the context of information seeking support. Finally, we discuss tools that implement aspects of what we consider important in this context. | [
2349
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428 | 1 | Feature Subset Selection Using A Genetic Algorithm Practical pattern classification and knowledge discovery problems require selection of a subset of attributes or features (from a much larger set) to represent the patterns to be classified. This paper presents an approach to the multi-criteria optimization problem of feature subset selection using a genetic algorithm. Our experiments demonstrate the feasibility of this approach for feature subset selection in the automated design of neural networks for pattern classification and knowledge discovery. 1 Introduction Many practical pattern classification tasks (e.g., medical diagnosis) require learning of an appropriate classification function that assigns a given input pattern (typically represented using a vector of attribute or feature values) to one of a finite set of classes. The choice of features, attributes, or measurements used to represent patterns that are presented to a classifier affect (among other things): ffl The accuracy of the classification function that can be learn... | [
839,
1411,
2126
] | Train |
429 | 4 | Personality-Driven Social Behaviors in Believable Agents Agents are considered "believable" when they are viewed by an audience as endowed with thoughts, desires, and emotions, typical of different personalities. The paper describes our work in progress aimed at realizing believable agents that perform helping behaviors influenced by their own personalities; the latter are represented as different clusters of prioritized goals and preferences over plans for achieving the goals. The implementation is based on the integration of a statebased planner that serves as the reasoning tool for the agents and a situation-driven execution system. Introduction "There is a notion in the Arts of `believable character '. It does not mean an honest or reliable character, but one that provides the illusion of life, and thus permits the audience's suspension of disbelief 1 . The idea of believability has long been studied and explored in literature, theater, film, radio, drama, and other media ". (Bates 1994) Believability therefore refers to a character's... | [
476,
1664,
2247
] | Validation |
430 | 2 | Multivariate Information Bottleneck The Information bottleneck method is an unsupervised non-parametric data organization technique. Given a joint distribution P (A; B), this method constructs a new variable T that extracts partitions, or clusters, over the values of A that are informative about B. The information bottleneck has already been applied to document classification, gene expression, neural code, and spectral analysis. In this paper, we introduce a general principled framework for multivariate extensions of the information bottleneck method. This allows us to consider multiple systems of data partitions that are inter-related. Our approach utilizes Bayesian networks for specifying the systems of clusters and what information each captures. We show that this construction provides insight about bottleneck variations and enables us to characterize solutions of these variations. We also present a general framework for iterative algorithms for constructing solutions, and apply it to several examples. | [
487,
732,
1726,
2680
] | Train |
431 | 2 | ConfSeek - A Multi-user, Multi-Threaded Specialized Search Engine for Conferences The explosive growth of the World Wide Web - the latest estimates for its size are around 1,000,000,000 web-pages - has made critical the need to nd information more accurately than what the current generic search engines can deliver. This project implements a prototype specialized search engine that allows user to submit queries for conferences in a specic eld of interest, and returns the detailed information about those conferences (deadlines, etc.). It uses multiple existing search engines to provide better coverage of the information available on the Internet. It can interact with multiple users concurrently and makes use of multi-threading to achieve faster information processing. The goal is to make this tool available to the scientic community to provide researchers with improved access to conference information. We discuss possible extensions (e.g. ranking of conferences according to their `quality', trip planning, etc.). Contents 1 Introduction 2 2 Goals of this Project... | [
1321
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432 | 3 | Automatic I/O Hint Generation through Speculative Execution Aggressive prefetching is an effective technique for reducing the execution times of disk-bound applications; that is, applications that manipulate data too large or too infrequently used to be found in file or disk caches. While automatic prefetching approaches based on static analysis or historical access patterns are effective for some workloads, they are not as effective as manually-driven (programmer-inserted) prefetching for applications with irregular or input-dependent access patterns. In this paper, we propose to exploit whatever processor cycles are left idle while an application is stalled on I/O by using these cycles to dynamically analyze the application and predict its future I/O accesses. Our approach is to speculatively pre-execute the application's code in order to discover and issue hints for its future read accesses. Coupled with an aggressive hint-driven prefetching system, this automatic approach could be applied to arbitrary applications, and should be particularl... | [
1549
] | Train |
433 | 2 | Aliasing on the World Wide Web: Prevalence and Performance Implications Aliasing occurs in Web transactions when requests containing different URLs elicit replies containing identical data payloads. Aliasing can cause cache misses, and there is reason to suspect that offthe -shelf Web authoring tools might increase aliasing on the Web. Existing research literature, however, says little about the prevalence of aliasing in user-initiated transactions or its impact on endto -end performance in large multi-level cache hierarchies. | [
3061,
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] | Train |
434 | 2 | Building Intelligent Systems For Mining Information Extraction Rules From Web Pages By Using Domain Knowledge Previous researches on automatic information extraction experienced difficulties in acquiring and representing useful domain knowledge and in coping with the structural heterogeneity among different information sources. As a result, many real-world information sources with complex document structures could not be correctly analyzed. In order to resolve these problems, this paper presents a method of building intelligent systems for mining information extraction rules from semi-structured Web pages by using domain knowledge. This system automatically generates a wrapper for each information source and performs information extraction and information integration by applying this wrapper to the corresponding source. Both the domain knowledge and the wrapper are represented by XML documents to increase flexibility and interoperability. By testing our prototype system on several real-estate information sites, we can claim that it creates the correct wrappers for most Web sources and consequently facilitates effective information extraction for heterogeneous information sources. 1. | [
2068,
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435 | 2 | Using Models of Score Distributions in Information Retrieval Empirical modeling of a number of different text search engines shows that the score distributions on a per query basis may be fitted approximately using an exponential distribution for the set of nonrelevant documents and a normal distribution for the set of relevant documents. This model fits not only probabilistic search engines like INQUERY but also vector space search engines like SMART and also LSI search engines. The model also appears to be true of search engines operating on a number of different languages. This leads to the hypothesis that all 'good' text search engines operating on any language have similar characteristics. The question then arises as to whether the shape of the score distributions reflects some underlying model of language or the search process itself. We discuss how they arise given certain assumptions about word distributions in documents. We then show that given a query for which relevance information is not available, a mixture model consisting of an exponential and a normal distribution can be fitted to the score distribution. These distributions can be used to map the scores of a search engine to probabilities. This model has many possible applications. For example, the outputs of different search engines can be combined by averaging the probabilities (optimal if the search engines are independent) or by using the probabilities to select the best engine for each query. Results show that the technique performs as well as the best current combination techniques. A number of different IR tasks may benefit from score modeling including filtering, multi-lingual retrieval and relevance feedback. We also discuss possible future improvements to the process of score modeling. 1. | [
887,
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] | Train |
436 | 3 | An Extended Entity-Relationship Approach to Data Management in Object-Oriented Systems Database programming in object-oriented systems can be supported by combining data modelling and programming technologies such that a data model supports the management of collections of objects where those objects are as specified by the underlying object-oriented programming language. This approach is the basis of the object data management services (ODMS) of the Comandos system. The ODMS data model provides constructs for the representation of both entities and their relationships and further supports rich classification structures. To complement the structural model, there is an operational model based on an algebra over collections of objects. 1 Introduction Object-oriented technologies are gaining in popularity as the basis for software development platforms. Meanwhile the family of entity-relationship data models retain their wide-spread use and popularity for conceptual modelling. How then can these two successful technologies be combined to support the development of ... | [
344,
823,
2241,
2295
] | Train |
437 | 5 | Path Planning Using Lazy PRM This paper describes a new approach to probabilistic roadmap planners (PRMs). The overall theme of the algorithm, called Lazy PRM, is to minimize the number of collision checks performed during planning and hence minimize the running time of the planner. Our algorithm builds a roadmap in the configuration space, whose nodes are the user-defined initial and goal configurations and a number of randomly generated nodes. Neighboring nodes are connected by edges representing paths between the nodes. In contrast with PRMs, our planner initially assumes that all nodes and edges in the roadmap are collision-free, and searches the roadmap at hand for a shortest path between the initial and the goal node. The nodes and edges along the path are then checked for collision. If a collision with the obstacles occurs, the corresponding nodes and edges are removed from the roadmap. Our planner either finds a new shortest path, or first updates the roadmap with new nodes and edges, and then searches for a shortest path. The above process is repeated until a collision-free path is returned. | [
841,
1003
] | Validation |
438 | 0 | Multi-Agent Architectures as Organizational Structures A Multi-Agent System (MAS) is an organization of coordinated autonomous agents that interact in order to achieve particular, possible common goals. Considering real world organizations as an analogy, this paper proposes architectural styles for MAS which adopt concepts from organizational theories. The styles are modeled using the i* framework which o#ers the notions of actor, goal and actor dependency and specified in Formal Tropos. They are evaluated with respect to a set of software quality attributes, such as predictability or adaptability. In addition, we conduct a comparative study of organizational and conventional software architectures using the mobile robot control example from the Software Engineering literature. The research is conducted in the context of Tropos, a comprehensive software system development methodology. | [
424,
1107,
1867,
2243,
2321,
2359
] | Validation |
439 | 2 | A Unifying Approach to HTML Wrapper Representation and Learning . The number, the size, and the dynamics of Internet information sources bears abundant evidence of the need for automation in information extraction. This calls for representation formalisms that match the World Wide Web reality and for learning approaches and learnability results that apply to these formalisms. The concept of elementary formal systems is appropriately generalized to allow for the representation of wrapper classes which are relevant to the description of Internet sources in HTML format. Related learning results prove that those wrappers are automatically learnable from examples. This is setting the stage for information extraction from the Internet by exploitation of inductive learning techniques. 1 Motivation Today's online access to millions or even billions of documents in the World Wide Web is a great challenge to research areas related to knowledge discovery and information extraction (IE). The general task of IE is to locate specific pieces of text i... | [
1171,
1287,
2133,
2391,
2765,
2796,
3098
] | Test |
440 | 3 | Probabilistic Default Reasoning with Conditional Constraints We present an approach to reasoning from statistical and subjective knowledge, which is based on a combination of probabilistic reasoning from conditional constraints with approaches to default reasoning from conditional knowledge bases. More precisely, we introduce the notions of -, lexicographic, and conditional entailment for conditional constraints, which are probabilistic generalizations of Pearl's entailment in system , Lehmann's lexicographic entailment, and Geffner's conditional entailment, respectively. We show that the new formalisms have nice properties. In particular, they show a similar behavior as referenceclass reasoning in a number of uncontroversial examples. The new formalisms, however, also avoid many drawbacks of reference-class reasoning. More precisely, they can handle complex scenarios and even purely probabilistic subjective knowledge as input. Moreover, conclusions are drawn in a global way from all the available knowledge as a whole. We then show that the new formalisms also have nice general nonmonotonic properties. In detail, the new notions of -, lexicographic, and conditional entailment have similar properties as their classical counterparts. In particular, they all satisfy the rationality postulates proposed by Kraus, Lehmann, and Magidor, and they have some general irrelevance and direct inference properties. Moreover, the new notions of - and lexicographic entailment satisfy the property of rational monotonicity. Furthermore, the new notions of -, lexicographic, and conditional entailment are proper generalizations of both their classical counterparts and the classical notion of logical entailment for conditional constraints. Finally, we provide algorithms for reasoning under the new formalisms, and we analyze its computational com... | [
510,
1078,
1907
] | Train |
441 | 3 | Updating Extended Logic Programs through Abduction . This paper introduces techniques for updating knowledge bases represented in extended logic programs. Three di#erent types of updates, view updates, theory updates, and inconsistency removal, are considered. We formulate these updates through abduction, and provide methods for computing them with update programs. An update program is an extended logic program which specifies changes on abductive hypotheses, then updates are computed by the U-minimal answer sets of an update program. The proposed technique provides a uniform framework for these di#erent types of updates, and each update is computed using existing procedures of logic programming. 1 Introduction A knowledge base must be updated when new information arrives. There are three cases in updating a knowledge base. The first one is that a knowledge base contains two di#erent kinds of knowledge --- variable knowledge and invariable knowledge. In this case, updates are permitted only on variable knowledge. Updates on the invari... | [
872,
1458,
2442
] | Train |
442 | 1 | Building Intelligent Agents for Web-Based Tasks: A Theory-Refinement Approach We present and evaluate an infrastructure with which to rapidly and easily build intelligent software agents for Web-based tasks. Our design is centered around two basic functions: ScoreThisLink and ScoreThisPage. If given highly accurate such functions, standard heuristic search would lead to efficient retrieval of useful information. Our approach allows users to tailor our system 's behavior by providing approximate advice about the above functions. This advice is mapped into neural network implementations of the two functions. Subsequent reinforcements from the Web (e.g., dead links) and any ratings of retrieved pages that the user wishes to provide are, respectively, used to refine the link- and page-scoring functions. Hence, our agent architecture provides an appealing middle ground between nonadaptive "agent" programming languages and systems that solely learn user preferences from the user's ratings of pages. We present a case study where we provide some simple advice and speci... | [
119,
3152
] | Train |
443 | 3 | Mining Knowledge in Geographical Data this article, a short overview is provided to summarize recent studies on spatial data mining, including spatial data mining techniques, their strengths and weaknesses, how and when to apply them, and what are the challenges yet to be faced. | [
2485
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444 | 3 | A Vision for Management of Complex Models Many problems encountered when building applications of database systems involve the manipulation of models. By “model, ” we mean a complex structure that represents a design artifact, such as a relational schema, object-oriented interface, UML model, XML DTD, web-site schema, semantic network, complex document, or software configuration. Many uses of models involve managing changes in models and transformations of data from one model into another. These uses require an explicit representation of “mappings ” between models. We propose to make database systems easier to use for these applications by making “model ” and “model mapping ” first-class objects with special operations that simplify their use. We call this capability model management. In addition to making the case for model management, our main contribution is a sketch of a proposed data model. The data model consists of formal, object-oriented structures for representing models and model mappings, and of high-level algebraic operations on those structures, such as matching, differencing, merging, function application, selection, inversion and instantiation. We focus on structure and semantics, not implementation. 1 | [
1099,
1819,
2237
] | Train |
445 | 0 | A Multidimentional Framework for the Evaluation of Multiagent System Methodologies Because of the great interest in using multiagent systems (MAS) in a wide variety of applications in recent years, agent-oriented methodologies and related modeling techniques have become a priority for the development of large scale agent-based systems. The work we present here belongs to the disciplines of Software Engineering and Distributed Artificial Intelligence. More specifically, we are interested in software engineering aspects involved in the development of multiagent systems (MAS). Several methodologies have been proposed for the development of MAS. For the most part, these methodologies remain incomplete: they are either an extension of object-oriented methodologies or an extension of knowledge-based methodologies. In addition, too little effort has gone into the standardization of MAS methodologies, platforms and environments. It seems obvious, therefore, that software engineering aspects of the development of MAS still remains an open field. The success of the agent paradigm requires systematic methodologies for the specification, analysis and design of "non toy" MAS applications. We present in this paper a new framework called MUCCMAS, which stands for MUltidimensional framework of Criteria for the Comparison of MAS methodologies, that enabled us to make a comparative analysis of existing main MAS methodologies. | [
2343
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446 | 1 | Is Machine Colour Constancy Good Enough? . This paper presents a negative result: current machine colour constancy algorithms are not good enough for colour-based object recognition. This result has surprised us since we have previously used the better of these algorithms successfully to correct the colour balance of images for display. Colour balancing has been the typical application of colour constancy, rarely has it been actually put to use in a computer vision system, so our goal was to show how well the various methods would do on an obvious machine colour vision task, namely, object recognition. Although all the colour constancy methods we tested proved insufficient for the task, we consider this an important finding in itself. In addition we present results showing the correlation between colour constancy performance and object recognition performance, and as one might expect, the better the colour constancy the better the recognition rate. 1 Introduction We set out to show that machine colour constancy had matured to... | [] | Train |
447 | 1 | A Model of Saliency-based Visual Attention for Rapid Scene Analysis A visual attention system, inspired by the behavior and the neuronal architecture of the early primate visual system, is presented. Multiscale image features are combined into a single topographical saliency map. A dynamical neural network then selects attended locations in order of decreasing saliency. The system breaks down the complex problem of scene understanding by rapidly selecting, in a computationally efficient manner, conspicuous locations to be analyzed in detail. Index terms: Visual attention, scene analysis, feature extraction, target detection, visual search. \Pi I. Introduction Primates have a remarkable ability to interpret complex scenes in real time, despite the limited speed of the neuronal hardware available for such tasks. Intermediate and higher visual processes appear to select a subset of the available sensory information before further processing [1], most likely to reduce the complexity of scene analysis [2]. This selection appears to be implemented in the ... | [
339,
1160,
2018
] | Train |
448 | 3 | A Runtime System for Interactive Web Services Interactive web services are increasingly replacing traditional static web pages. Producing web services seems to require a tremendous amount of laborious lowlevel coding due to the primitive nature of CGI programming. We present ideas for an improved runtime system for interactive web services built on top of CGI running on virtually every combination of browser and HTTP/CGI server. The runtime system has been implemented and used extensively in <bigwig>, a tool for producing interactive web services. Keywords: CGI, Interactive Web Service, Web Document Management, Runtime System, Session Model. 1 Introduction An interactive web service consists of a global shared state (typically a database) and a number of distinct sessions that each contain some local private state and a sequential, imperative action. A web client may invoke an individual thread of one of the given session kinds. The execution of this thread may interact with the client and inspect or modify the global state. One... | [
328
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449 | 5 | Rigid and Articulated Motion Seen with an Uncalibrated Stereo Rig This paper establishes a link between uncalibrated stereo vision and the motion of rigid and articulated bodies. The variation in the projective reconstruction of a dynamic scene over time allows an uncalibrated stereo rig to be used as a faithful motion capturing device. We introduce an original theoretical framework -- projective kinematics -- which allows rigid and articulated motion to be represented within the transformation group of projective space. Corresponding projective velocities are defined in the tangent space. Most importantly, these projective motions inherit the Lie-group structure of the displacement group. These theoretical results lead immediately to nonmetric formulations of visual servoing, tracking, motion capturing and motion synthesis systems, that no longer require the metric geometry of a stereo camera or of the articulated body to be known. We report on such a nonmetric formulation of a visual servoing system and present simulated experimental results. 1 In... | [
2142
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450 | 0 | Intelligent Agents -- A New Technology for Future Distributed Sensor Systems? This master thesis deals with intelligent agents and the possibility to use the intelligent agent technology in future distributed sensor systems. The term future distributed sensor system refers to a system based on several sensors that will be developed within a period of five to ten years. Since researchers have not agreed on a more precise definition of intelligent agents, we first examined what constitutes an intelligent agent and made a definition suited for our application domain. We used our definition as a base for investigating if and how intelligent agents can be used in future distributed sensor systems. We argue that it is not interesting to come up with a general agent definition applicable to every agent, instead one should make a foundation for a definition. When this is done we can decide on more specific features depending on the task the agent will perform and in what domain the agent will work in. Finally we conclude that it is possible to use the agent technology i... | [
1943,
2064
] | Test |
451 | 5 | Regulating Human-Robot Interaction using "emotions", "drives" and facial expressions This paper presents a motivational system for an autonomous robot which is designed to regulate humanrobot interaction. The mode of social interaction is that of a caretaker-infant dyad where a human acts as the caretaker for the robot. The robot's motivational system is designed to generate an analogous interaction for a robot-human dyad as for an infantcaretaker dyad. An infant's emotions and drives play a very important role in generating meaningful interactions with the caretaker (Bullowa 1979). Similarly, the learning task for the robot is to apply various communication skills acquired during social exchanges to manipulate the caretaker such that its drives are satisfied. Toward this goal, the motivational system implements drives, emotions, and facial expressions. The interaction is regulated specifically to promote a suitable learning environment. Although the details of the learning itself are beyond the scope of this paper, this work represents an important step toward realiz... | [
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452 | 3 | SQL Based Association Rule Mining using Commercial RDBMS (IBM DB2 UDB EEE) . Data mining is becoming increasingly important since the size of databases grows even larger and the need to explore hidden rules from the databases becomes widely recognized. Currently database systems are dominated by relational database and the ability to perform data mining using standard SQL queries will definitely ease implementation of data mining. However the performance of SQL based data mining is known to fall behind specialized implementation and expensive mining tools being on sale. In this paper we present an evaluation of SQL based data mining on commercial RDBMS (IBM DB2 UDB EEE). We examine some techniques to reduce I/O cost by using View and Subquery. Those queries can be more than 6 times faster than SETM SQL query reported previously. In addition, we have made performance evaluation on parallel database environment and compared the performance result with commercial data mining tool (IBM Intelligent Miner). We prove that SQL based data mining can achie... | [] | Train |
453 | 0 | Analysis on a Mobile Agent Based Algorithm for Network Management Recent advance in the agent technology has brought in a new method for network routing, the ant routing algorithm. Although its effectiveness and efficiency have been demonstrated and reported in the literature, its properties have not yet been well studied. This paper will present some preliminary analysis of this algorithm in regard to its population growing property and jumping behavior. For both synchronized and asynchronized networks, we have shown that the expected number of agents in a node is no more than (1 +max i fj\Omega i jg)km, where j\Omega i j is the number of neighbor hosts of the i th host; k is the number of agents generated per request and m is the average number of requests. It is shown that under a mild condition, for all p (1 + max i fj\Omega i jg)km, the probability of the number of agents in a node exceeding p is less than R 1 p P(x)dx; where P(x) is a normal distributed function with mean and variance given by (1+max i fj\Omega i jg)km and (km)... | [
2831
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454 | 3 | The i.com Tool for Intelligent Conceptual Modelling In this paper we present i.com, a tool for intelligent conceptual modelling. i.com allows for the specification of multiple EER diagrams and inter- and intra-schema constraints. Complete logical reasoning is employed by the tool to verify the specification, infer implicit facts, and manifest any inconsistencies. 1 Introduction i.com is a tool supporting the conceptual design phase of an information system, and in particular of an integration information system -- such as a data warehouse. The tool is an evolution of part of the conceptual modelling demonstrators suite [Jarke et al., 2000] developed within the European ESPRIT Long Term Research Data Warehouse Quality (DWQ) project [Jarke et al., 1999] . i.com adopts an extended Entity-Relationship (EER) conceptual data model, enriched with multidimensional aggregations and interschema constraints. i.com is fully integrated with a very powerful description logics reasoning server which acts as a background inference engine. The co... | [
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] | Train |
455 | 1 | Situated Neuro-Fuzzy Control for Vision-Based Robot Localisation We introduce a neuro-fuzzy system for localising mobile robot solely based on raw vision data without relying on landmarks or artificial symbols. In an initial learning step the system is trained on the compressed input data so as to classify different situations and to associate appropriate behaviours to these situations. Input data may, for example, be generated by an omnidirectional vision system obviating the need for active cameras. At run time the compressed input data are fed into different B-spline fuzzy controllers which determine the correspondence between the actual situation and the situation they were trained for. The matching controller may then directly drive the actuators to realise the desired behaviour. The system thus realises a tight coupling between a very high-dimensional input parameter space and the robot actuators. It is completely free of any internal models such as maps of the environment, the algorithms are straightforward to implement and the computational ... | [
597
] | Test |
456 | 3 | Efficient Computation of Temporal Aggregates with Range Predicates A temporal aggregation query is an important but costly operation for applications that maintain timeevolving data (data warehouses, temporal databases, etc.). Due to the large volume of such data, performance improvements for temporal aggregation queries are critical. In this paper we examine techniques to compute temporal aggregates that include key-range predicates (range temporal aggregates). In particular we concentrate on SUM, COUNT and AVG aggregates. This problem is novel; to handle arbitrary key ranges, previous methods would need to keep a separate index for every possible key range. We propose an approach based on a new index structure called the Multiversion SB-Tree, which incorporates features from both the SB-Tree and the Multiversion B-Tree, to handle arbitrary key-range temporal SUM, COUNT and AVG queries. We analyze the performance of our approach and present experimental results that show its efficiency. 1 | [
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457 | 4 | The PLAY Research Group: Entertainment and Innovation in Sweden In a short time the research group PLAY has established an unorthodox but effective work style, where a creative approach to research in information technology is combined with a strong focus on achieving high-quality results. Being a young research group (both regarding the time it has existed and the average age of its members) has presented PLAY with both challenges and opportunities. We face the challenge of building a credible basis for research in the academic community, but also think that we have the opportunity to contribute innovative results to the research community and our industrial partners. Keywords HCI research groups, future HCI, European HCI, IT design INTRODUCTION How can one perform exciting and unorthodox research in information technology, while still assuring that results are useful and of good quality? How can a small group, consisting mostly of relatively inexperienced students, in a small country with very little traditions in groundbreaking IT research, ... | [
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458 | 5 | A Survey on Knowledge Compilation this paper we survey recent results in knowledge compilation of propositional knowledge bases. We first define and limit the scope of such a technique, then we survey exact and approximate knowledge compilation methods. We include a discussion of compilation for non-monotonic knowledge bases. Keywords: Knowledge Representation, Efficiency of Reasoning | [
1236,
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] | Test |
459 | 0 | More Realistic Human Behavior Models for Agents in Virtual Worlds: Emotion, Stress, and Value Ontologies This paper focuses on challenges to improving the behavioral realism of computer generated agents and attempts to reflect the state of the art in human behavior modeling with particular attention to value ontologies, emotion, and stress in game-theoretic settings. The goal is to help those interested in constructing more realistic software agents for use in simulations, in virtual reality environments, and in training and performance aiding settings such as on the web or in embedded applications. This paper pursues this goal by providing a framework for better integrating the theories and models contained in the diverse human behavior modeling literatures, such as those that straddle physiological, cognitive and emotive processes; individual differences; emergent group and crowd behavior; and (punctuated) equilibria in social settings. The framework is based on widely available ontologies of world values and how these and physiological factors might be construed emotively into subjective expected utilities to guide the reactions and deliberations of agents. For example what makes one set of opponent groups differ from another? This framework serves as an extension of Markov decision processes appropriate for iterative play in game-theoretic settings, with particular emphasis on agent capabilities for redefining drama and for finding meta-games to counter the human player. This article presents the derivation of the framework and some initial results and lessons learned about integrating behavioral models into interactive dramas and meta-games that stimulate (systemic) thought and training doctrine. 1) | [
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460 | 3 | Temporal Statement Modifiers A wide range of database applications manage time-varying data. Many temporal query languages have been proposed, each one the result of many carefully made yet subtly interacting design decisions. In this article we advocate a different approach to articulating a set of requirements, or desiderata, that directly imply the syntactic structure and core semantics of a temporal extension of an (arbitrary) nontemporal query language. These desiderata facilitate transitioning applications from a nontemporal query language and data model, which has received only scant attention thus far. The paper then introduces the notion of statement modifiers that provide a means of systematically adding temporal support to an existing query language. Statement modifiers apply to all query language statements, for example, queries, cursor definitions, integrity constraints, assertions, views, and data manipulation statements. We also provide a way to systematically add temporal support to an existing implementation. The result is a temporal query language syntax, semantics, and implementation that derives from first principles. We exemplify this approach by extending SQL-92 with statement modifiers. This extended language, termed ATSQL, is formally defined via a denotational-semantics-style mapping of | [
10,
869
] | Validation |
461 | 3 | Selecting and Materializing Horizontally Partitioned Warehouse Views Data warehouse views typically store large aggregate tables based on a subset of dimension attributes of the main data warehouse fact table. Aggregate views can be stored as 2 n subviews of a data cube with n attributes. Methods have been proposed for selecting only some of the data cube views to materialize in order to speed up query response time, accommodate storage space constraint and reduce warehouse maintenance cost. This paper proposes a method for selecting and materializing views, which selects and horizontally fragments a view, recomputes the size of the stored partitioned view while deciding further views to select. # 2001 Elsevier Science B.V. All rights reserved. Keywords: Data warehouse; Views; Fragmentation; Performance benet 1. Introduction Decision support systems (DSS) used by business executives require analyzing snapshots of departmental databases over several periods of time. Departmental databases of the same organization (e.g., a bank) may be stored on dier... | [
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462 | 5 | Adaptive Heterogeneous Multi-Robot Teams This research addresses the problem of achieving fault tolerant cooperation within small- to medium-sized teams of heterogeneous mobile robots. We describe a novel behavior-based, fully distributed architecture, called ALLIANCE, that utilizes adaptive action selection to achieve fault tolerant cooperative control in robot missions involving loosely coupled tasks. The robots in this architecture possess a variety of high-level functions that they can perform during a mission, and must at all times select an appropriate action based on the requirements of the mission, the activities of other robots, the current environmental conditions, and their own internal states. Since such cooperative teams often work in dynamic and unpredictable environments, the software architecture allows the team members to respond robustly and reliably to unexpected environmental changes and modi cations in the robot team that may occur due to mechanical failure, the learning of new skills, or the addition or removal of robots from the team by human intervention. After presenting ALLIANCE, we describe in detail our experimental results of an implementation of this architecture on a team of physical mobile robots performing a cooperative box pushing demonstration. These experiments illustrate the ability ofALLIANCE to achieve adaptive, fault-tolerant cooperative control amidst dynamic changes in the capabilities of the robot team. | [
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463 | 3 | DataFoundry: Information Management for Scientific Data Data warehouses and data marts have been successfully applied to a multitude of commercial business applications. They have proven to be invaluable tools by integrating information from distributed, heterogeneous sources and summarizing this data for use throughout the enterprise. Although the need for information dissemination is as vital in science as in business, working warehouses in this community are scarce because traditional warehousing techniques don't transfer to scientific environments. There are two primary reasons for this difficulty. First, schema integration is more difficult for scientific databases than for business sources, because of the complexity of the concepts and the associated relationships. While this difference has not yet been fully explored, it is an important consideration when determining how to integrate autonomous sources. Second, scientific data sources have highly dynamic data representations (schemata). When a data source participating in a warehouse... | [
2035,
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] | Test |
464 | 3 | Deductive Database Languages: Problems and Solutions this paper, we discuss these problems from four different aspects: complex values, object orientation, higher-orderness, and updates. In each case, we examine four typical languages that address the corresponding issues. | [
418,
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465 | 2 | Regression Models for Ordinal Data: A Machine Learning Approach In contrast to the standard machine learning tasks of classification and metric regression we investigate the problem of predicting variables of ordinal scale, a setting referred to as ordinal regression. The task of ordinal regression arises frequently in the social sciences and in information retrieval where human preferences play a major role. Also many multi--class problems are really problems of ordinal regression due to an ordering of the classes. Although the problem is rather novel to the Machine Learning Community it has been widely considered in Statistics before. All the statistical methods rely on a probability model of a latent (unobserved) variable and on the condition of stochastic ordering. In this paper we develop a distribution independent formulation of the problem and give uniform bounds for our risk functional. The main difference to classification is the restriction that the mapping of objects to ranks must be transitive and asymmetric. Combining our theoretical framework with results from measurement theory we present an approach that is based on a mapping from objects to scalar utility values and thus guarantees transitivity and asymmetry. Applying the principle of Structural Risk Minimization as employed in Support Vector Machines we derive a new learning algorithm based on large margin rank boundaries for the task of ordinal regression. Our method is easily extended to nonlinear utility functions. We give experimental results for an Information Retrieval task of learning the order of documents with respect to an initial query. Moreover, we show that our algorithm outperforms more naive approaches to ordinal regression such as Support Vector Classification and Support Vector Regression in the case of more than two ranks. | [
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466 | 2 | Designing a Digital Library for Young Children: An Intergenerational Partnership As more information resources become accessible using computers, our digital interfaces to those resources need to be appropriate for all people. However when it comes to digital libraries, the interfaces have typically been designed for older children or adults. Therefore, we have begun to develop a digital library interface developmentally appropriate for young children (ages 5-10 years old). Our prototype system we now call "QueryKids" offers a graphical interface for querying, browsing and reviewing search results. This paper describes our motivation for the research, the design partnership we established between children and adults, our design process, the technology outcomes of our current work, and the lessons we have learned. Keywords Children, digital libraries, information retrieval design techniques, education applications, participatory design, cooperative inquiry, intergenerational design team, zoomable user interfaces (ZUIs). THE NEED FOR RESEARCH A growing body of k... | [
1011,
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] | Train |
467 | 1 | A Sound Algorithm for Region-Based Image Retrieval Using an Index Region-based image retrieval systems aim to improve the effectiveness of content-based search by decomposing each image into a set of "homogeneous" regions. Thus, similarity between images is assessed by computing similarity between pairs of regions and then combining the results at the image level. In this paper we propose the first provably sound algorithm for performing region-based similarity search when regions are accessed through an index. Experimental results demonstrate the effectiveness of our approach, as also compared to alternative retrieval strategies. 1. Introduction Many real world applications, in the field of medicine, weather prediction, and communications, to name a few, require efficient access to image databases based on content. To this end, the goal of content-based image retrieval (CBIR) systems is to define a set of properties (features) able to effectively characterize the content of images and then to use such features during retrieval. Users accessing a CB... | [
2891
] | Validation |
468 | 4 | A Wearable Spatial Conferencing Space Wearable computers provide constant access to computing and communications resources. In this paper we describe how the computing power of wearables can be used to provide spatialized 3D graphics and audio cues to aid communication. The result is a wearable augmented reality communication space with audio enabled avatars of the remote collaborators surrounding the user. The user can use natural head motions to attend to the remote collaborators, can communicate freely while being aware of other side conversations and can move through the communication space. In this way the conferencing space can support dozens of simultaneous users. Informal user studies suggest that wearable communication spaces may offer several advantages, both through the increase in the amount of information it is possible to access and the naturalness of the interface. 1: Introduction One of the broad trends emerging in human-computer interaction is the increasing portability of computing and communication fac... | [
618,
1261,
1757,
2166,
2365,
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] | Train |
469 | 4 | Confluence of Computer Vision and Interactive Graphics for Augmented Reality . Augmented reality #AR# is a technology in which a user's view of the real world is enhanced or augmented with additional information generated from a computer model. Using AR technology, users can interact with a combination of real and virtual objects in a natural way. This paradigm constitutes the core of a very promising new technology for many applications. However, before it can be applied successfully, AR has to ful#ll very strong requirements including precise calibration, registration and tracking of sensors and objects in the scene, as well as a detailed overall understanding of the scene. At ECRCwe see computer vision and image processing technology play an increasing role in acquiring appropriate sensor and scene models. To balance robustness with automation, weintegrate automatic image analysis with both interactive user assistance and input from magnetic trackers and CAD-models. Also, in order to meet the requirements of the emerging global information society... | [
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] | Train |
470 | 1 | Hybrid Coordination of Reinforcement Learning-based Behaviors for AUV Control This paper proposes a Hybrid Coordination method for Behavior-based Control Architectures. The hybrid method takes in advantages of the robustness and modularity in competitive approaches as well as optimized trajectories in cooperative ones. This paper will demonstrate the feasibility of this hybrid method with a 3D-navigation application to an Autonomous Underwater Vehicle (AUV). The behaviors were learnt online by means of Reinforcement Learning. Q(l)- learning was used extending the one-step learning of the popular Q-learning to n-steps. Realistic simulations were carried out. Results showed the good performance of the hybrid method on behavior coordination as well as on increasing and improving behavior learning. | [
880,
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] | Train |
471 | 2 | Authoritative Sources in a Hyperlinked Environment The link structure of a hypermedia environment can be a rich source of information about the content of the environment, provided we have effective means for understanding it. Versions of this principle have been studied in the hypertext research community and (in a context predating hypermedia) through journal citation analysis in the field of bibliometrics. But for the problem of searching in hyperlinked environments such as the World Wide Web, it is clear from the prevalent techniques that the information inherent in the links has yet to be fully exploited. In this work we develop a new method for automatically extracting certain types of information about a hypermedia environment from its link structure, and we report on experiments that demonstrate its effectiveness for a variety of search problems on the www. The central problem we consider is that of determining the relative "authority" of pages in such environments. This issue is central to a number of basic hypertext search t... | [
95,
255,
263,
301,
538,
702,
737,
742,
848,
865,
949,
1069,
1167,
1393,
1420,
1512,
1767,
1827,
1983,
2038,
2102,
2106,
2179,
2471,
2777,
2920,
2995,
3016
] | Validation |
472 | 1 | Hybrid Neural Systems This chapter provides an introduction to the eld of hybrid neural systems. Hybrid neural systems are computational systems which are based mainly on articial neural networks but also allow a symbolic interpretation or interaction with symbolic components. In this overview, we will describe recent results of hybrid neural systems. We will give a brief overview of the main methods used, outline the work that is presented here, and provide additional references. We will also highlight some important general issues and trends. | [
1531,
1603
] | Test |
473 | 0 | Design Issues for Mixed-Initiative Agent Systems This paper addresses the effect of mixed-initiative systems on multiagent systems design. A mixed-initiative system is one in which humans interact directly with software agents in a collaborative approach to problem solving. There are two main levels at which multiagent systems are designed: the domain level and the individual agent level. At the domain level, there are few unique challenges to mixedinitiative system design. However, at the individual agent level, the agent itself must be designed to interact with the human and the agent system, integrating the two into a single system. Introduction Much of the current research related to intelligent agents has focused on the capabilities and structure of individual agents. However, in order to solve complex problems, these agents must work cooperatively with other agents in a heterogeneous environment. This is the domain of Multiagent Systems. In multiagent systems, we are interested in the coordinated behavior of a system of indiv... | [
1414
] | Validation |
474 | 3 | Symbolic Representation of User-defined Time Granularities In the recent literature on time representation, an effort has been made to characterize the notion of time granularity and the relationships between granularities, in order to have a common framework for their specification, and to allow the interoperability of systems adopting different time granularities. This paper considers the mathematical characterization of finite and periodical time granularities, and it identifies a user-friendly symbolic formalism which captures exactly that class of granularities. This is achieved by a formal analysis of the expressiveness of well-known symbolic representation formalisms. 1. Introduction There is a wide agreement in the AI and database community on the requirement for a data/knowledge representation system of supporting standard as well as user-defined time granularities. Examples of standard time granularities are days, weeks, months, while user defined granularities may include businessweeks, trading-days, working-shifts, school-terms, wi... | [
1072
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475 | 3 | Query Optimization in the Presence of Limited Access Patterns 1 Introduction The goal of a query optimizer of a database system is to translate a declarative query expressed on a logical schema into an imperative query execution plan that accesses the physical storage of the data, and applies a sequence of relational operators. In building query execution plans, traditional relational query optimizers try to find the most efficient method for accessing the necessary data. When possible, a query optimizer will use auxiliary data structures such as an index on a file in order to efficiently retrieve a certain set of tuples in a relation. However, when such structures do not exist or are not useful for the given query, the alternative of scanning the entire relation always exists. The existence of the fall back option to perform a complete scan is an important assumption in traditional query optimization. Several recent query processing applications have the common characteristic that it is not always possible to perform complete scans on the data. Instead, the query optimization problem is complicated by the fact that there are only limited access patterns to the data. One such | [
923,
930,
2149,
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] | Train |
476 | 0 | A Proposal for an Agent Architecture for Proactive Persistent Non Player Characters In the past, games development has been driven by the need to achieve more realistic graphics. | [
429,
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] | Test |
477 | 2 | Text and Image Metasearch on the Web As the Web continues to increase in size, the relative coverage of Web search engines is decreasing, and search tools that combine the results of multiple search engines are becoming more valuable. This paper provides details of the text and image metasearch functions of the Inquirus search engine developed at the NEC Research Institute. For text metasearch, we describe features including the use of link information in metasearch, and provide statistics on the usage and performance of Inquirus and the Web search engines. For image metasearch, Inquirus queries multiple image search engines on the Web, downloads the actual images, and creates image thumbnails for display to the user. Inquirus handles image search engines that return direct links to images, and engines that return links to HTML pages. For the engines that return HTML pages, Inquirus analyzes the text on the pages in order to predict which images are most likely to correspond to the query. The individual image search engin... | [
165,
488,
1321,
1838,
2503,
2532,
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] | Train |
478 | 2 | Athena: Mining-based Interactive Management of Text Databases Abstract. We describe Athena: a system for creating, exploiting, and maintaining a hierarchy of textual documents through interactive miningbased operations. Requirements of any such system include speed and minimal end-user e ort. Athena satis es these requirements through linear-time classi cation and clustering engines which are applied interactively to speed the development of accurate models. Naive Bayes classi ers are recognized to be among the best for classifying text. We show that our specialization of the Naive Bayes classi er is considerably more accurate (7 to 29 % absolute increase in accuracy) than a standard implementation. Our enhancements include using Lidstone's law of succession instead of Laplace's law, under-weighting long documents, and over-weighting author and subject. We also present a new interactive clustering algorithm, C-Evolve, for topic discovery. C-Evolve rst nds highly accurate cluster digests (partial clusters), gets user feedback to merge and correct these digests, and then uses the classi cation algorithm to complete the partitioning of the data. By allowing this interactivity in the clustering process, C-Evolve achieves considerably higher clustering accuracy (10 to 20 % absolute increase in our experiments) than the popular K-Means and agglomerative clustering methods. 1 | [
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] | Train |
479 | 1 | Convergence Theory and Applications of the Factorized Distribution Algorithm The paper investigates the optimization of additively decomposable functions (ADF) by a new evolutionary algorithm called Factorized Distribution Algorithm (FDA). FDA is based on a factorization of the distribution to generate search points. First separable ADFs are considered. These are mapped to generalized linear functions with metavariables defined for multiple alleles. The mapping transforms FDA into an Univariate Marginal Frequency Algorithm (UMDA). For UMDA the exact equation for the response to selection is computed under the assumption of proportionate selection. For truncation selection an approximate equation for the time to convergence is used, derived from an analysis of the OneMax function. FDA is also numerically investigated for non separable functions. The time to convergence is very similar to separable ADFs. FDA outperforms the genetic algorithm with recombination of strings by far. Keywords response to selection, Fisher's Theorem, additively decomposable functions... | [
1830
] | Validation |
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