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2,480 | 0 | Behavior Coordination Mechanisms - State-of-the-art In behavior-based robotics the control of a robot is shared between a set of purposive perception-action units, called behaviors. Based on selective sensory information, each behavior produces immediate reactions to control the robot with respect to a particular objective, i.e., a narrow aspect of the robot's overall task such as obstacle avoidance or wall following. Behaviors with di erent and possibly incommensurable objectives may produce con icting actions that are seemingly irreconcilable. Thus a major issue in the design of behavior-based control systems is the formulation of e ective mechanisms for coordination of the behaviors' activities into strategies for rational and coherent behavior. This is known as the action selection problem (also refereed to as the behavior coordination problem) and is the primary focus of this overview paper. Numerous action selection mechanisms have been proposed over the last decade and the main objective of this document istogive a qualitative overview of these approaches. 2 1 | [
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2,481 | 3 | Backtracking Algorithms for Disjunctions of Temporal Constraints We extend the framework of simple temporal problems studied originally by Dechter, Meiri and Pearl to consider constraints of the form x1 \Gamma y1 r1 : : : xn \Gamma yn rn , where x1 : : : xn ; y1 : : : yn are variables ranging over the real numbers, r1 : : : rn are real constants, and n 1. We have implemented four progressively more efficient algorithms for the consistency checking problem for this class of temporal constraints. We have partially ordered those algorithms according to the number of visited search nodes and the number of performed consistency checks. Finally, we have carried out a series of experimental results on the location of the hard region. The results show that hard problems occur at a critical value of the ratio of disjunctions to variables. This value is between 6 and 7. Introduction Reasoning with temporal constraints has been a hot research topic for the last fifteen years. The importance of this problem has been demonstrated in many areas of artifici... | [
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2,482 | 1 | Detecting Intrusions Using System Calls: Alternative Data Models Intrusion detection systems rely on a wide variety of observable data to distinguish between legitimate and illegitimate activities. In this paper we study one such observable---sequences of system calls into the kernel of an operating system. Using system-call data sets generated by several different programs, each consisting both of normal and intrusive behavior, we compare the ability of different data-modeling methods to represent normal behavior accurately and to recognize intrusions. We compare the following methods: simple enumeration of observed sequences, methods based on relative frequencies of different sequences, a data mining technique, and Hidden Markov Models (HMMs). All of the methods perform adequately, with HMMs giving the best overall results. We discuss the factors affecting the performance of each method, and conclude that for this particular problem, weaker methods than HMMs are likely sufficient. 1 Introduction In 1996, Forrest and others introduced a simple in... | [
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2,483 | 1 | MOCSYN: Multiobjective Core-Based Single-Chip System Synthesis In this paper, we present a system synthesis algorithm, called MOCSYN, which partitions and schedules embedded system specifications to intellectual property cores in an integrated circuit. Given a system specification consisting of multiple periodic task graphs as well as a database of core and integrated circuit characteristics, MOCSYN synthesizes real-time heterogeneous single-chip hardware-software architectures using an adaptive multiobjective genetic algorithm that is designed to escape local minima. The use of multiobjective optimization allows a single system synthesis run to produce multiple designs which trade off different architectural features. Integrated circuit price, power consumption, and area are optimized under hard real-time constraints. MOCSYN differs from previous work by considering problems unique to single-chip systems. It solves the problem of providing clock signals to cores composing a system-on-a-chip. It produces a bus structure which balances ease of layo... | [
1687
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2,484 | 2 | Stylistic Experiments For Information Retrieval . A discussion on various experiments to utilize stylistic variation among texts for information retrieval purposes. 1. Stylistics Texts vary in many ways. Authors make choices when they write a text: they decide how to organize the material they have planned to introduce; they make choices between synonyms and syntactic constructions; they choose an intended audience for the text. Authors will make these choices in various ways and for various reasons: based on personal preferences, on their view of the reader, and on what they know and like about other similar texts. A style is a consistent and distinguishable tendency to make some of these linguistic choices. Style is, on a surface level, very obviously detectable as the choice between items in a vocabulary, between types of syntactical constructions, between the various ways a text can be woven from the material it is made of. It is the information carried in a text when compared to other texts, or in a sense compared to language... | [
647,
902,
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] | Train |
2,485 | 3 | Generalizing Temporal Dependencies for Non-Temporal Dimensions Recently, there has been a lot of interest in temporal granularity, and its applications in temporal dependency theory and data mining. Generalization hierarchies used in multi-dimensional databases and OLAP serve a role similar to that of time granularity in temporal databases, but they also apply to non-temporal dimensions, like space. | [
443,
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2,486 | 4 | Simulated Ship Shock Tests/Trials? This paper contrasts the relative, overall utilities of ship Shock Tests/Trials and simulations. A list of advantages | [
68,
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991,
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2,487 | 3 | Reasoning over Conceptual Schemas and Queries in Temporal Databases This paper introduces a new logical formalism, intended for temporal conceptual modelling, as a natural combination of the wellknown description logic DLR and pointbased linear temporal logic with Since and Until. The expressive power of the resulting DLRUS logic is illustrated by providing a systematic formalisation of the most important temporal entity-relationship data models appeared in the literature. We define a query language (where queries are nonrecursive Datalog programs and atoms are complex DLRUS expressions) and investigate the problem of checking query containment under the constraints defined by DLRUS conceptual schemas, as well as the problems of schema satisfiability and logical implication. Although it is shown that reasoning in full DLRUS is undecidable, we identify the decidable (in a sense, maximal) fragment DLR US by allowing applications of temporal operators to formulas and entities only (but not to relation expressions). We obtain the following hierarchy of complexity results: (a) reasoning in DLR US with atomic formulas is EXPTIME-complete, (b) satisfiability and logical implication of arbitrary DLR US formulas is EXPSPACE-complete, and (c) the problem of checking query containment of non-recursive Datalog queries under DLR US constraints is decidable in 2EXPTIME. | [
108,
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2,488 | 3 | Indexing Moving Points We propose three indexing schemes for storing a set S of N points in the plane, each moving along a linear trajectory, so that a query of the following form can be answered quickly: Given a rectangle R and a real value t q , report all K points of S that lie inside R at time t q . We first present an indexing structure that, for any given constant " ? 0, uses O(N=B) disk blocks, where B is the block size, and answers a query in O((N=B) 1=2+" + K=B) I/Os. It can also report all the points of S that lie inside R during a given time interval. A point can be inserted or deleted, or the trajectory of a point can be changed, in O(log 2 B N) I/Os. Next, we present a general approach that improves the query time if the queries arrive in chronological order, by allowing the index to evolve over time. We obtain a tradeoff between the query time and the number of times the index needs to be updated as the points move. We also describe an indexing scheme in which the number of I/Os required to answer a query depends monotonically on the difference between t q and the current time. Finally, we develop an efficient indexing scheme to answer approximate nearest-neighbor queries among moving points. An extended abstract of this paper appeared in the Proceedings of the 19th ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems. y Center for Geometric Computing, Department of Computer Science, Duke University, Box 90129, Durham, NC 27708--0129; pankaj@cs.duke.edu; http://www.cs.duke.edu/ pankaj. Supported in part by National Science Foundation grants EIA--9870734, EIA--9972879, and CCR--9732787, by Army Research Of fice MURI grant DAAH04-- 96--1--0013, by a Sloan fellowship, and by a grant from the U.S.-Israeli Binational Science Foundation. z Center ... | [
6,
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2,489 | 1 | An Investigation of Machine Learning Based Prediction Systems Traditionally, researchers have used either o€-the-shelf models such as COCOMO, or developed local models using statistical techniques such as stepwise regression, to obtain software e€ort estimates. More recently, attention has turned to a variety of machine learning methods such as arti®cial neural networks (ANNs), case-based reasoning (CBR) and rule induction (RI). This paper outlines some comparative research into the use of these three machine learning methods to build software e€ort prediction systems. We brie¯y describe each method and then apply the techniques to a dataset of 81 software projects derived from a Canadian software house in the late 1980s. We compare the prediction systems in terms of three factors: accuracy, explanatory value and con®gurability. We show that ANN methods have superior accuracy and that RI methods are least accurate. However, this view is somewhat counteracted by problems with explanatory value and con®gurability. For example, we found that considerable e€ort was required to con®gure the ANN and that this compared very unfavourably with the other techniques, particularly CBR and least squares regression (LSR). We suggest that further work be carried out, both to further explore interaction between the enduser | [
1844,
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] | Train |
2,490 | 2 | Machine Learning for Intelligent Processing of Printed Documents . A paper document processing system is an information system component which transforms information on printed or handwritten documents into a computer-revisable form. In intelligent systems for paper document processing this information capture process is based on knowledge of the speci#c layout and logical structures of the documents. This article proposes the application of machine learning techniques to acquire the speci#c knowledge required byan intelligent document processing system, named WISDOM++, that manages printed documents, such as letters and journals. Knowledge is represented by means of decision trees and #rst-order rules automatically generated from a set of training documents. In particular, an incremental decision tree learning system is applied for the acquisition of decision trees used for the classi- #cation of segmented blocks, while a #rst-order learning system is applied for the induction of rules used for the layout-based classi#cation and understanding of d... | [
2191
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2,491 | 1 | Evolving Materialized Views in Data Warehouse A data warehouse contains multiple views accessed by queries. One of the most important decisions in designing a data warehouse is the selection of materialized views for the purpose of efficiently implementing decision making. The search space for the selection of materialized views is exponentially large, therefore, heuristics have been used to search a small fraction of the space to get a near optimal solution. In this paper, we explore the use of a genetic algorithm for the selection of materialized views based on multiple global processing plans for many queries. Our experimental studies indicate that the genetic algorithm delivers better solutions than some heuristics. 1 Introduction A Data Warehouse (DW) is a repository of integrated information available for querying and analysis. DW is an approach to the integration of data from multiple, possibly very large, distributed, heterogeneous databases and other information sources. In this paper, DW data model is based on SPJ (Sele... | [
2585
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2,492 | 1 | Using Decision Tree Confidence Factors for Multiagent Control . Although Decision Trees are widely used for classification tasks, they are typically not used for agent control. This paper presents a novel technique for agent control in a complex multiagent domain based on the confidence factors provided by the C4.5 Decision Tree algorithm. Using Robotic Soccer as an example of such a domain, this paper incorporates a previously-trained Decision Tree into a full multiagent behavior that is capable of controlling agents throughout an entire game. Along with using Decision Trees for control, this behavior also makes use of the ability to reason about action-execution time to eliminate options that would not have adequate time to be executed successfully. This multiagent behavior represents a bridge between low-level and high-level learning in the Layered Learning paradigm. The newly created behavior is tested empirically in game situations. 1 Introduction Multiagent Systems is the subfield of AI that aims to provide both principles for construction... | [
266,
287,
346,
864
] | Train |
2,493 | 4 | Multimodal Man-Machine Interface for Mission Planning This paper presents a multimodal interface featuring fusion of multiple modalities for natural human-computer interaction. The architecture of the interface and the methods applied are described, and the results of the real-time multimodal fusion are analyzed. The research in progress concerning a mission planning scenario is discussed and other possible future directions are also presented. Keywords Multimodal interfaces, speech recognition, microphonearray, force-feedback tactile glove, gaze tracking, military maps INTRODUCTION Current human-machine communication systems predominantly use keyboard and mouse inputs that inadequately approximate human abilities for communication. More natural communication technologies such as speech, sight and touch, are capable of freeing computer users from the constraints of keyboard and mouse. Although they are not sufficiently advanced to be used individually for robust human-machine communication, they have adequately advanced to serve simul... | [
1454,
1562
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2,494 | 1 | Self-Learning Techniques for Grapheme-to-Phoneme Conversion In this article, we present a comprehensive review of various experiences with different self-learning techniques applied to the task of converting a graphemic string into the corresponding phonemic sequence. We also report some experiments carried out both with English words and French proper names. These experiments support the view that taking full advantage of the huge pronunciation dictionaries that we have been developing during the ONOMASTICA project is possible only if the traditional understanding of grapheme-tophoneme conversion as a classification problem is questioned. | [
355
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2,495 | 5 | Facilitating Hard Active Database Applications Machine Interface.............................................................................................. 26 3.2.3 Concurrency Control....................................................................................................... 27 3.3 VENUSDB LANGUAGE SEMANTICS: AN EVALUATION ............................................................ 28 3.3.1 Related Work.................................................................................................................... 30 3.3.2 The Mortgage Pool Allocation Problem .......................................................................... 33 3.3.3 Quantitative Results ......................................................................................................... 37 3.3.4 Discussion and Conclusions ............................................................................................ 43 CHAPTER 4 APPLICATION SEMANTICS FOR ACTIVE LOG MONITORING APPLICATIONS ............................................................................................45 4.1 MOTIVATION ........................................................................................................................... 46 4.1.1 Coupling Modes............................................................................................................... 47 4.1.2 Example 1 ........................................................................................................................ 48 4.2 BACKGROUND.......................................................................................................................... 50 4.2.1 LMAs, Datalog, and Confluence ..................................................................................... 50 4.2.2 Previous Work.................................................... | [
123,
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2,496 | 5 | A hybrid projection based and radial basis function architecture: Initial values and global optimization We introduce a hybrid architecture of projection based units and radial basis functions as a general function estimation scheme. In particular, we introduce an optimization scheme which has several steps and assures a convergence to a useful solution. During training a determination whether a Gaussian unit should be removed is applied. This results in a final architecture with much smaller number of units. The proposed global constrained optimization does not lead to overfitting which happens when the RBF width becomes too small, this is achieved by a regularization mechanism. Classification and regression results are demonstrated on various benchmark data sets and compared with several variants of RBF networks. The most striking performance improvement is achieved on the vowel data set [5]. Keywords: Projection units, RBF Units, Hybrid Network Architecture, SMLP, Clustering, Regularization. 1 Introduction The duality between projection-based approximation and radial kernel... | [] | Train |
2,497 | 4 | Levels of Control and Closure in Complex Semiotic Systems It is natural to advance closures as "atomic" processes of universal evolution, and to analyze this concept specifically. While real complex systems like organisms and complex mechanisms cannot exist at either extreme of complete closure or lack of closure, nevertheless we should consider the properties of closures in general: the introduction of boundaries; a corresponding stability; the establishment of system autonomy and identity; and thereby the introduction of emergent new systems of potentially new types. Our focus should move from simple physical closure of common objects and classical self-organizing systems to semiotically closed systems which maintain cyclic relations of perception, interpretation, decision, and action with their environments. Thus issues arise concerning the use and interpretation of symbols, representations, and/or internal models (whether explicit or implicit) by the system; and the syntactic, semantic, and pragmatic relations among the sign tok... | [
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2,498 | 2 | Agents advanced features for negotiation in Electronic Commerce and Virtual Organisations formation process Electronic Commerce technology has changed the way traditional business is being done. Transactions' complexity is increased due both to the huge amount of available information and also to the environment dynamics. Moreover, Electronic Commerce has enabled the arising of new economical structures, as it is the case of Virtual Organisations. Our research aims at providing flexible and general-purpose systems for intelligent negotiation, both for Electronic Commerce and Virtual Organisation formation. This paper proposes an Electronic Market architecture implemented through a Multi-Agent system. This architecture includes both a specific market agent which plays the role of market coordinator, as well as agents representing the individual business partners with their own goals and strategies. We also include a sophisticated negotiation protocol through multi-criteria and distributed constraint formalisms. An online, continuous reinforcement learning algorithm has been designed to enab... | [
350,
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] | Train |
2,499 | 3 | A Data Model and Algebra for Probabilistic Complex Values . We present a probabilistic data model for complex values. More precisely, we introduce probabilistic complex value relations, which combine the concept of probabilistic relations with the idea of complex values in a uniform framework. We elaborate a model-theoretic definition of probabilistic combination strategies, which has a rigorous foundation on probability theory. We then define an algebra for querying database instances, which comprises the operations of selection, projection, renaming, join, Cartesian product, union, intersection, and difference. We prove that our data model and algebra for probabilistic complex values generalizes the classical relational data model and algebra. Moreover, we show that under certain assumptions, all our algebraic operations are tractable. We finally show that most of the query equivalences of classical relational algebra carry over to our algebra on probabilistic complex value relations. Hence, query optimization techniques for class... | [
510,
1078,
2500
] | Test |
2,500 | 3 | Extension of the Relational Algebra to Probabilistic Complex Values We present a probabilistic data model for complex values. More precisely, we introduce probabilistic complex value relations, which combine the concept of probabilistic relations with the idea of complex values in a uniform framework. We then de ne an algebra for querying database instances, which comprises the operations of selection, projection, renaming, join, Cartesian product, union, intersection, and difference. We finally show that most of the query equivalences of classical relational algebra carry over to our algebra on probabilistic complex value relations. Hence, query optimization techniques for classical relational algebra can easily be applied to optimize queries on probabilistic complex value relations. | [
510,
1078,
1786,
2499
] | Validation |
2,501 | 0 | Highly-Available Firewall Service using Virtual Redirectors This paper introduces the dependable decentralised system architecture developed by the PHDS group. It describes the virtual redirector utilised by this architecture and how a decentralised network layer firewall application is implemented on it. Dependability of the design is achieved through the use of fault-tolerant protocols. The virtual redirector is implemented by a dynamic hashing algorithm, which uses load information and the fault/working status of nodes in the system. The focus of this paper is the implementation of a testbed which is used to compare the performance and availability of the decentralised firewall against a monolithic firewall with equivalent functionality. Keywords: dependable computing, internet, security, firewall, fault-tolerant protocol Category: research paper, student paper Contents 1 Introduction 2 2 The PHDS Architecture 3 2.1 Autonomous Decentralised Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.2 The PHDS System for Inter... | [
627
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2,502 | 1 | Intelligent Data Analysis in Medicine Extensive amounts of knowledge and data stored in medical databases require the development of specialized tools for storing and accessing of data, data analysis, and effective use of stored knowledge and data. This paper focuses on methods and tools for intelligent data analysis, aimed at narrowing the increasing gap between data gathering and data comprehension. The paper sketches the history of research that led to the development of current intelligent data analysis techniques, discusses the need for intelligent data analysis in medicine, and proposes a classification of intelligent data analysis methods. The scope of the paper covers temporal data abstraction methods and data mining methods. A selection of methods is presented and illustrated in medical problem domains. Presently data abstraction and data mining are attracting considerable research interest. However the two technologies, in spite of the fact that they share their central objective, namely the intelligen... | [
745,
1391
] | Train |
2,503 | 2 | The Anatomy of a Large-Scale Hypertextual Web Search Engine In this paper, we present Google, a prototype of a large-scale search engine which makes heavy use of the structure present in hypertext. Google is designed to crawl and index the Web efficiently and produce much more satisfying search results than existing systems. The prototype with a full text and hyperlink database of at least 24 million pages is available at http://google.stanford.edu/ To engineer a search engine is a challenging task. Search engines index tens to hundreds of millions of web pages involving a comparable number of distinct terms. They answer tens of millions of queries every day. Despite the importance of large-scale search engines on the web, very little academic research has been done on them. Furthermore, due to rapid advance in technology and web proliferation, creating a web search engine today is very different from three years ago. This paper provides an in-depth description of our large-scale web search engine -- the first such detailed public description we know of to date. Apart from the problems of scaling traditional search techniques to data of this magnitude, there are new technical challenges involved with using the additional information present in hypertext to produce better search results. This paper addresses this question of how to build a practical large-scale system which can exploit the additional information present in hypertext. Also we look at the problem of how to effectively deal with uncontrolled hypertext collections where anyone can publish anything they want. | [
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146... | Train |
2,504 | 4 | Quantum Treemaps and Bubblemaps for a Zoomable Image Browser This paper describes two algorithms for laying out groups of objects in a 2D space-filling manner. Quantum Treemaps are a variation on existing treemap algorithms that are designed for laying out images or other objects of indivisible (quantum) size. They build on the Ordered Treemap algorithm, but guarantees that every generated rectangle will have a width and height that are an integral multiple of an input object size. Bubblemaps also fill space with groups of quantum-sized objects, but generate nonrectangular blobs, and utilize space more efficiently. Both algorithms have been applied to PhotoMesa, an application that supports browsing of large numbers of images. PhotoMesa uses a Zoomable User Interface with a simple interaction designed for novices and family use. Keywords Zoomable User Interfaces (ZUIs), Treemaps, Image Browsers, Animation, Graphics, Jazz. | [
311,
466,
1011,
2366,
2681
] | Validation |
2,505 | 3 | Dynamic Pipeline Scheduling for Improving Interactive Query Performance Interactive query performance is becoming an important criterion for online systems where delivering query results in a timely fashion is critical. Pipelined execution is a promising query execution style that can produce the initial portion of the result early and in a continuous fashion. In this paper we propose techniques for delivering results faster in a pipelined query plan. We distinguish between two cases. For cases where the tuples in the query result are of the same importance we propose a dynamic rate-based pipeline scheduling policy that produces more results during the early stages of query execution. | [
2769
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2,506 | 3 | Automatic Reclustering of Objects in Very Large Databases for High Energy Physics In the very large object database systems planned for some future particle physics experiments, typical physics analysis jobs will traverse millions of read-only objects, many more objects than fit in the database cache. Thus, a good clustering of objects on disk is highly critical to database performance. We present the implementation and performance measurements of a prototype reclustering mechanism which was developed to optimise I/O performance under the changing access patterns in a high energy physics database. Reclustering is done automatically and on-line. The methods used by our prototype differ greatly from those commonly found in proposed general-purpose reclustering systems. By exploiting some special characteristics of the access patterns of physics analysis jobs, the prototype manages to keep database I/O throughput close to the optimum throughput of raw sequential disk access. Keywords: Object oriented databases, object clustering, object reclustering, automatic reclust... | [
162,
504,
1271,
1934,
2719,
3124
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2,507 | 3 | Implementation and Performance Analysis of Incremental Equations for Nested Relations View materialization is an important way of improving the performance of query processing. When an update occurs to the source data from which a materialized view is derived, the materialized view has to be updated so that it is consistent with the source data. This update process is called view maintenance. The incremental method of view maintenance, which computes the new view using the old view and the update to the source data, is widely preferred to full view recomputation when the update is small in size. The small update size becomes an important concept for measuring the cheap performance of the incremental methods. In this paper, we investigate what is the limit of the small update size, which we call size limit for the incremental maintenance. When the size of an update exceeds the limit, the incremental maintenance is no longer cheaper than the view recomputation. The investigation is based on incremental equations for operators in the nested relational model... | [
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2,508 | 3 | A Framework for Designing and Implementing the User Interface of a Geographic Digital Library . Geographic data are useful for a large set of applications, such as urban planning and environmental control. These data are, however, very expensive to acquire and maintain. Moreover, their use is often restricted due to a lack of dissemination mechanisms. Digital libraries are a good approach for increasing data availability and therefore reducing costs, since they provide e#cient storage and access to large volumes of data. One major drawback to this approach is that it creates the necessity of providing facilities for a large and heterogeneous community of users to search and interact with these geographic libraries. We present a solution to this problem, based on a framework that allows the design and construction of customizable user interfaces for applications based on Geographic Digital Libraries (GDL). This framework relies on two main concepts: a geographic user interface architecture and a geographic digital library model. Key words: Digital libraries -- User interfaces -... | [
1674
] | Validation |
2,509 | 3 | Query-By-Trace: Visual Predicate Specification In Spatio-Temporal Databases In this paper we propose a visual interface for the specification of predicates to be used in queries on spatio-temporal databases. The approach is based on a visual specification method for temporally changing spatial situations. This extends existing concepts for visual spatial query languages, which are only capable of querying static spatial situations. We outline a preliminary user interface that supports the specification on an intuitive and easily manageable level, and we describe the design of the underlying visual language. The visual notation can be used directly as a visual query interface to spatio-temporal databases, or it can provide predicate specifications that can be integrated into textual query languages leading to heterogeneous languages. Key Words Spatio-Temporal Queries, Visual Predicate Specification, Visual Database Interface 1. INTRODUCTION Spatio-temporal databases deal with spatial objects that change over time (for example, they move or they grow): cars, ... | [
341,
1081,
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] | Test |
2,510 | 4 | OZONE: A Zoomable Interface for Navigating Ontology Information We present OZONE (Zoomable Ontology Navigator), for searching and browsing ontological information. OZONE visualizes query conditions and provides interactive, guided browsing for DAML (DARPA Agent Markup Language) ontologies. To visually represent objects in DAML, we define a visual model for its classes, properties and relationships between them. Properties can be expanded into classes for query refinement. The visual query can be formulated incrementally as users explore class and property structures interactively. Zoomable interface techniques are employed for effective navigation and usability. Keywords: Ontology, DAML, Browsing, Zoomable User Interface (ZUI), Jazz, WWW. | [
759,
900,
1011,
2918
] | Test |
2,511 | 4 | Roomware for Cooperative Buildings: Integrated Design of Architectural Spaces and Information Spaces . In this paper, we introduce the concepts of "cooperative buildings" and "roomware" and place them in the context of the integrated design of real, physical, resp. architectural spaces and virtual, resp. digital information spaces. By "roomware " we mean computer-augmented things in rooms, like doors, walls, furniture, and others. The general approach is detailed via examples from the i-LAND project where we develop several "roomware" components in order to realize an interactive information and cooperation landscape, e.g. an innovative work environment for creativity teams. We describe the current realization of i-LAND which includes an interactive electronic wall, an interactive table, computer-augmented chairs, and a mechanism for assigning physical objects as representatives of information objects in the virtual world. Keywords. cooperative buildings, shared workspaces, physical space, architecture, virtual world, information space, augmented reality, roomware, furnitu... | [
1304,
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] | Validation |
2,512 | 3 | Architecture and Quality in Data Warehouses: an Extended Repository Approach This paper makes two | [
490,
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2,513 | 1 | Approximate Statistical Tests for Comparing Supervised Classification Learning Algorithms This paper reviews five approximate statistical tests for determining whether one learning algorithm out-performs another on a particular learning task. These tests are compared experimentally to determine their probability of incorrectly detecting a difference when no difference exists (type I error). Two widely-used statistical tests are shown to have high probability of Type I error in certain situations and should never be used. These tests are (a) a test for the difference of two proportions and (b) a paired-differences t test based on taking several random train/test splits. A third test, a paired-differences t test based on 10-fold cross-validation, exhibits somewhat elevated probability of Type I error. A fourth test, McNemar's test, is shown to have low Type I error. The fifth test is a new test, 5x2cv, based on 5 iterations of 2-fold cross-validation. Experiments show that this test also has acceptable Type I error. The paper also measures the power (ability to detect algorit... | [
630,
724,
751,
934,
1279,
2317,
2676,
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2,514 | 0 | Facilitating Message Exchange though Middle Agents To utilize services provided by other agents, a requesting agent needs to locate and communicate with these service providers. Specifically, in order to interoperate with the providers, the requesting agent should know: 1) the service provider's interface; 2) the ontology that defines concepts used by the provider; and 3) the agent communication language (ACL) the agent uses so that it can parse and understand the communication. Currently deployed Multi-Agent Systems (MAS) encode the interface description and the ontology within a service provider's capability description (or advertisement) that is registered with a Middle Agent; however, this assumes a common ACL between communicating agents. We demonstrate how agents can communicate with each other using a template-based shallow parsing approach to constructing and decomposing messages, thus relaxing assumptions on the ACLs and message formats used. | [
297,
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1962
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2,515 | 0 | Agent-Based Programming Language for Multi-Agent Teams This report specifies a programming language for multi-agent teams. The language aims at providing an abstract level approach to the programming of teams composed of either software or hardware agents (e.g., robots), encapsulating the lower level implementation details (e.g., graphical primitives for icon animation, robot motion primitives) and providing an abstraction level appropriate for multi-agent systems. The overall architecture of the multi-agent team, the language specifications and an example of application to robotic soccer are included. Keywords: Cooperative Robotics, Multi-Agent Systems, Distributed Artificial Intelligence, Robotic Soccer (tactics) strategy world state WORLD Relational Rules Behavior11 Behavior12 Behavior1M BehaviorN1 BehaviorN2 BehaviorNM act sense act sense negotiation requests (strategy prescription) Organizational State-Machine (behavior prescription, temporary behavior modification) world + team state Behavior ij : behavior i of agent j behavior... | [
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] | Train |
2,516 | 3 | Efficient Bulk Operations on Dynamic R-trees In recent years there has been an upsurge of interest in spatial databases. A major issue is how to manipulate efficiently massive amounts of spatial data stored on disk in multidimensional spatial indexes (data structures). Construction of spatial indexes (bulk loading) has been studied intensively in the database community. The continuous arrival of massive amounts of new data makes it important to update existing indexes (bulk updating) efficiently. In this paper we present a simple, yet efficient, technique for performing bulk update and query operations on multidimensional indexes. We present our technique in terms of the so-called R-tree and its variants, as they have emerged as practically efficient indexing methods for spatial data. Our method uses ideas from the buffer tree lazy buffering technique and fully utilizes the available internal memory and the page size of the operating system. We give a theoretical analysis of our technique, showing that it is efficient both in terms of I/O communication, disk storage, and internal computation time. We also present the results of an extensive set of experiments showing that in practice our approach performs better than the previously best known bulk update methods with respect to update time, and that it produces a better quality index in terms of query performance. One important novel feature of our technique is that in most cases it allows us to perform a batch of updates and queries simultaneously. To be able to do so is essential in environments where queries have to be answered even while the index is being updated and reorganized. | [
1214
] | Validation |
2,517 | 4 | Characterizing A Media-Enhanced Classroom Server Media-enhanced classrooms are changing the way we teach and learn. Servers for such applications differ from a typical web server in the nature and geographic spread of the user community and the type of information accessed from the server. This paper compares the workload of the Classroom 2000 server, a media-enhanced classroom server, with that of a typical web server. We find several similarities and differences between the two workloads. One of the most striking differences is that the inter-reference times for files accessed more than once from the Classroom 2000 server are not independent, as opposed to those of a web server. We show that the user interface presented by the Classroom 2000 server affects server workload. We find that client-side caching improves over time. Finally, in addition to accessing lecture material for their current courses, students also access archieved material from previous quarters. 1 Introduction Recent improvements in computational power... | [
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2,518 | 3 | A Survey of Proxy Cache Evaluation Techniques Proxy caches are increasingly used around the world to reduce bandwidth requirements and alleviate delays associated with the World-Wide Web. In order to compare proxy cache performances, objective measurements must be made. In this paper, we define a space of proxy evaluation methodologies based on source of workload used and form of algorithm implementation. We then survey recent publications and show their locations within this space. 1 Introduction Proxy caches are increasingly used around the world to reduce bandwidth and alleviate delays associated with the World-Wide Web. This paper describes the space of proxy cache evaluation methodologies and places current research within that space. The primary contributions of this paper are threefold: 1) definition and description of the space of evaluation techniques; 2) appraisal of the di#erent methods within that space; and 3) a survey of cache evaluation techniques from the research literature. In the next section we provide backgro... | [
797,
1074,
2760
] | Validation |
2,519 | 4 | Integrating Sounds and Motions in Virtual Environments Sounds are often the result of motions of virtual objects in a virtual environment. Therefore, sounds and the motions that caused them should be treated in an integrated way. When sounds and motions do not have the proper correspondence, the resultant confusion can lessen the effects of each. In this paper, we present an integrated system for modeling, synchronizing, and rendering sounds for virtual environments. The key idea of the system is the use of a functional representation of sounds, called timbre trees. This representation is used to model sounds that are parameterizable. These parameters can then be mapped to the parameters associated with the motions of objects in the environment. This mapping allows the correspondence of motions and sounds in the environment. Representing arbitrary sounds using timbre trees is a difficult process that we do not address in this paper. We describe approaches for creating some timbre trees including the use of genetic algorithms. Rendering the... | [
324
] | Train |
2,520 | 2 | Digital Libraries: A Generic Classification and Evaluation Scheme Evaluation of digital libraries (DLs) is essential for further development in this area. Whereas previous approaches were restricted to certain facets of the problem, we argue that evaluation of DLs should be based on a broad view of the subject area. For this purpose, we develop a new description scheme using four major dimensions: data/collection, system/technology, users, and usage. For each of these dimensions, we describe the major attributes. Using this scheme, existing DL test beds can be characterised. For this purpose, we have performed a survey by means of a questionnaire, which is now continued by setting up a DL meta-library. | [
2268
] | Train |
2,521 | 0 | A Survey of Factory Control Algorithms which Can be Implemented in a Multi-Agent Heterarchy: Dispatching, Scheduling, and Pull This paper has not seriously addressed the question of what new algorithms are inspired by the multi-agent heterarchical paradigm, except in two cases. The Market-Driven Contract Net uses a new form of forward / backward scheduling called `cost-based forward / backwards continuum scheduling' which was inspired by the common agent concept of bidding. Also, Duffie's current work on developing agent-based deterministic simulation would be a new form of deterministic simulation as it attempts to automate the human interaction normally required for successful implementation of such systems. But in general we still have an open question of what new algorithms heterarchical agent architectures imply and what would be the performance of these new algorithms. Because a multi-agent heterarchy is a distributed computing paradigm, it would be worthwhile to investigate the communications overhead of these algorithms. Such evaluations are not generally reported. Such research would assure that not only can these algorithms be implemented in a multi-agent heterarchy, but that their implementation does not require excessive communications overhead. 6. REFERENCES [1] H. Hayashi, "The IMS International Collaborative Program," in 24th ISIR, 1993, Japan Industrial Robot Association [2] National Center for Manufacturing Sciences, FOCUS: Exceeding Partner Expectations. Ann Arbor, MI: September, 1994. [3] S. Goldman and K. Preiss, Ed., 21st Century Manufacturing Enterprise Strategy: An Industry-Led View. Bethlehem, PA: Iacocca Institute, Lehigh University, 1991. [4] S. L. Goldman, R. N. Nagel and K. Preiss, Agile Competitors and Virtual Organizations: Strategies for Enriching the Customer. New York, NY: Van Nostrand Reinhold, 1995. [5] P. T. Kidd, Agile Manufacturing: Forging New Frontiers. W... | [
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2,522 | 2 | Maximum Entropy Markov Models for Information Extraction and Segmentation Hidden Markov models (HMMs) are a powerful probabilistic tool for modeling sequential data, and have been applied with success to many text-related tasks, such as part-of-speech tagging, text segmentation and information extraction. In these cases, the observations are usually modeled as multinomial distributions over a discrete vocabulary, and the HMM parameters are set to maximize the likelihood of the observations. This paper presents a new Markovian sequence model, closely related to HMMs, that allows observations to be represented as arbitrary overlapping features (such as word, capitalization, formatting, part-of-speech), and defines the conditional probability of state sequences given observation sequences. It does this by using the maximum entropy framework to fit a set of exponential models that represent the probability of a state given an observation and the previous state. We present positive experimental results on the segmentation of FAQ's. 1. Introdu... | [
2104,
2133,
2342,
2423,
2446,
2658,
2765,
2898
] | Validation |
2,523 | 1 | Shock Graphs and Shape Matching We have been developing a theory for the generic representation of 2-D shape, where structural descriptions are derived from the shocks (singularities) of a curve evolution process, acting on bounding contours. We now apply the theory to the problem of shape matching. The shocks are organized into a directed, acyclic shock graph, and complexity is managed by attending to the most significant (central) shape components first. The space of all such graphs is highly structured and can be characterized by the rules of a shock graph grammar. The grammar permits a reduction of a shock graph to a unique rooted shock tree. We introduce a novel tree matching algorithm which finds the best set of corresponding nodes between two shock trees in polynomial time. Using a diverse database of shapes, we demonstrate our system's performance under articulation, occlusion, and changes in viewpoint. Keywords: shape representation; shape matching; shock graph; shock graph grammar; subgraph isomorphism. 1 I... | [
1202,
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] | Train |
2,524 | 3 | A Comparative Study of Version Management Schemes for XML Documents The problem of managing multiple versions for XML documents and semistructured data is of significant interest in many DB applications and web-related services. Traditional document version control schemes, such as RCS, suffer from the following two problems. At the logical level, they conceal the structure of the documents by modeling them as sequences of text lines, and storing a document's evolution as a line-edit script. At the physical level, they can incur in severe storage or processing costs because of their inability to trade-off storage with computation. To solve these problems, we propose version management strategies that preserve the structure of the original document, and apply and extend DB techniques to minimize storage and processing costs. Therefore, we propose and compare three schemes for XML version management, namely, the Usefulness-Based Copy Control, the Multiversion B-Tree, and the Partially Persistent List Method. A common characteristic of these schemes is that they cluster data using the notion of page usefulness, which by selectively copying current information from obsolete pages provides for fast version reconstruction with minimal storage overhead. The cost and performance of these version management schemes are evaluated and compared through extensive analysis and experimentation. | [
731,
877,
2172,
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] | Train |
2,525 | 3 | FeedbackBypass: A New Approach to Interactive Similarity Query Processing In recent years, several methods have been proposed for implementing interactive similarity queries on multimedia databases. Common to all these methods is the idea to exploit user feedback in order to progressively adjust the query parameters and to eventually converge to an "optimal" parameter setting. However, all these methods also share the drawback to "forget" user preferences across multiple query sessions, thus requiring the feedback loop to be restarted for every new query, i.e. using default parameter values. Not only is this proceeding frustrating from the user's point of view but it also constitutes a significant waste of system resources. In this paper we present FeedbackBypass, a new approach to interactive similarity query processing. It complements the role of relevance feedback engines by storing and maintaining the query parameters determined with feedback loops over time, using a wavelet-based data structure (the Simplex Tree). For each query, a favorable set of query parameters can be determined and used to either "bypass" the feedback loop completely for already-seen queries, or to start the search process from a near-optimal configuration. FeedbackBypass can be combined well with all state-of-the-art relevance feedback techniques working in high-dimensional vector spaces. Its storage requirements scale linearly with the dimensionality of the query space, thus making even sophisticated query spaces amenable. Experimen- Permission to copy without fee all or part of this material is granted provided that the copies are not made or distributed for direct commercial advantage, the VLDB copyright notice and the title of the publication and its date appear, and notice is given that copying is by permission of the Very Large ... | [
2943,
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] | Validation |
2,526 | 4 | Making Context Explicit in Communicating Objects INTRODUCTION One can speak about context only with reference to something (no definition of context out of context): the context of an object, the context of interaction, the context of a problem solving, etc. However, only the context of interaction between agents seems of interest because it is in this context that other contexts are referenced or evolve. For example, if an object, as a telephone, could provide you the context in which the called person is (free, in meeting, phone on voice recorder), you could balance your wish to establish your communication versus the availability of the called person. Several domains have already elaborated their own working definition of context. In human-machine interaction, a context is a set of information that could be used to define and interpret a situation in which interact agents. In the context-aware applications community, the context is composed of a set of information for characterizing the situation in which interact humans, applic | [
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2,527 | 0 | Artificial Agents and Logic Programming . Artificial agents represent a new paradigm in software engineering and Artificial Intelligence. As complex software-controlled systems they are capable of flexible autonomous behavior in dynamic and unpredictable environments. Over the past few years, researchers in computer science have begun to recognise that the technology of artificial agents provides the key to solving many problems in distributed computing and intelligent control, for which traditional software engineering techniques offer no solution. The field of logic programming includes many important concepts, such as declarativity, unification, meta-logic programming, and deduction rules, from which the new technology of multiagent systems can benefit. 1 Introduction Although the idea of agent systems is intuitively appealing, and there are a number of implemented systems that claim to realize this popular idea, the basic concepts underlying these systems are often not well-understood, and no attempt is made to define t... | [
1552,
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] | Train |
2,528 | 1 | Fusion via a Linear Combination of Scores . We present a thorough analysis of the capabilities of the linear combination (LC) model for fusion of information retrieval systems. The LC model combines the results lists of multiple IR systems by scoring each document using a weighted sum of the scores from each of the component systems. We first present both empirical and analytical justification for the hypotheses that such a model should only be used when the systems involved have high performance, a large overlap of relevant documents, and a small overlap of nonrelevant documents. The empirical approach allows us to very accurately predict the performance of a combined system. We also derive a formula for a theoretically optimal weighting scheme for combining 2 systems. We introduce d -- the difference between the average score on relevant documents and the average score on nonrelevant documents -- as a performance measure which not only allows mathematical reasoning about system performance, but also allows the selection of w... | [
1038
] | Train |
2,529 | 4 | Towards Proximity Group Communication Group communication will undoubtedly be a useful paradigm for many applications of wireless networking in which reliability and timeliness are requirements. Moreover, location-awareness is clearly central to mobile applications such as traffic management and smart spaces. In this paper we introduce our definition of proximity groups in which group membership depends on location and then discuss some requirements for a group management service suitable for proximity groups. | [
41,
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] | Train |
2,530 | 0 | Incremental Reinforcement Learning for designing Multi-Agent Systems Designing individual agents so that, when put together, they reach a given global goal is not an easy task. One solution to automatically build such large Multi-Agent Systems is to use decentralized learning: each agent learns by itself its own behavior. To that purpose, Reinforcement Learning methods are very attractive as they do not require a solution of the problem to be known before hand. Nevertheless, many hard points need to be solved for such a learning process to be viable. Among others, the credit assignement problem, combinatorial explosion and local perception of the world seem the most crucial and prevent optimal behavior. In this paper, we propose a framework based on a gradual learning of harder and harder tasks until the desired global behavior is reached. The applicability of our paradigm is tested on computer experiments where many agents have to coordinate to reach a global goal. Our results show that incremental learning leads to better performances than more classical techniques. We then discuss several improvements which could lead to even better performances. | [
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2,531 | 0 | ISocRob - Intelligent Society of Robots Abstract. The SocRob project was born as a challenge for multidisciplinary research on broad and generic approaches for the design of a cooperative robot society, involving Control, Robotics and Artificial Intelligence researchers. A case study on Robotic Soccer played by a team of 3 robots has started two years ago and was first tested last year during RoboCup98. This experience has clearly revealed that the robotic soccer environment is a sufficiently rich, complex and dynamic testbed to study new methodologies both on Robotics and Artificial Intelligence. Therefore, the SocRob team is currently working on the SocRob project improvements and intends to compete at the World Cup of Robotic Soccer, RoboCup99, held in Stockholm, Sweden, in the middle-size league. In this paper the basic aspects of last year implementation as well as the improvements made meanwhile are briefly recalled and presented. Naturally, a special emphasis is given here to the novel solutions proposed for this year implementation, the results obtained and the expected future developments. 1 | [
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2,532 | 2 | Information Retrieval on the Web In this paper we review studies on the growth of the Internet and technologies which are useful for information search and retrieval on the Web. We present data on the Internet from several dierent sources, e.g., current as well as projected number of users, hosts and Web sites. Although numerical gures vary, overall trends cited by the sources are consistent and point to exponential growth in the past and in the coming decade. As such, it is not surprising that about 85% of Internet users surveyed claim to be using search engines and search services to nd speci c information of interest. The same surveys show, however, that users are not satis ed with the performance of the current generation of search engines; the slow speed of retrieval, communication delays, and poor quality of retrieved results (e.g., noise and broken links) are commonly cited problems. We discuss the development of new techniques which are targeted to resolve some of the problems associated with Web-... | [
477,
488,
721,
825,
1180,
1321,
2188,
2392,
2459,
2503,
3180
] | Validation |
2,533 | 1 | Reflective Metalogical Frameworks In computer science we speak of implementing a logic; this is done in a programming language, such as Lisp, called here the implementation language. We also reason about the logic, as in understanding how to search for proofs; these arguments are expressed in the metalanguage and conducted in the metalogic of the object language being implemented. We also reason about the implementation itself, say to know it is correct; this is done in a programming logic. How do all these logics relate? This paper considers that question and more. We show that by taking the view that the metalogic is primary, these other parts are related in standard ways. The metalogic should be suitably rich so that the object logic can be presented as an abstract data type, and it must be suitably computational (or constructive) so that an instance of that type is an implementation. The data type abstractly encodes all that is relevant for metareasoning, i.e., not only the term constructing functions but also the... | [
2355
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2,534 | 1 | Bringing People and Places Together with Dual Augmentation This paper describes initial work on the Domisilica project at Georgia Tech. We are exploring the dual augmentation of physical and virtual worlds in Domisilica and applying this novel concept to support home life beyond the boundaries of the actual house. We will demonstrate applications of dual augmentation in supporting distributed communities through a home (the Regency) and a specific appliance (CyberFridge), both of which serve as a communications link between physical and virtual worlds. Three specific types of communication are supported: direct (supporting real-time user-to-user interaction), indirect (interaction mediated by devices such as games, a refrigerator, etc), and peripheral (supporting awareness of subtle information). Keywords: Augmented reality, augmented virtuality, home, ubiquitous computing 1 Introduction Physical barriers such as time and distance have traditionally stood in the way of successfully building communities which are not located in a single geogr... | [
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2,535 | 2 | Grouper: A Dynamic Clustering Interface to Web Search Results Users of Web search engines are often forced to sift through the long ordered list of document "snippets" returned by the engines. The IR community has explored document clustering as an alternative method of organizing retrieval results, but clustering has yet to be deployed on most major search engines. The NorthernLight search engine organizes its output into "custom folders" based on pre-computed document labels, but does not reveal how the folders are generated or how well they correspond to users' interests. In this paper, we introduce Grouper -- an interface to the results of the HuskySearch meta-search engine, which dynamically groups the search results into clusters labeled by phrases extracted from the snippets. In addition, we report on the first empirical comparison of user Web search behavior on a standard ranked-list presentation versus a clustered presentation. By analyzing HuskySearch logs, we are able to demonstrate substantial differences in the number of documents f... | [
124,
193,
272,
370,
1105,
1627,
2705
] | Train |
2,536 | 0 | Let's Talk! Socially Intelligent Agents for Language Conversation Training Abstract — This paper promotes socially intelligent animated agents for the pedagogical task of English conversation training for native speakers of Japanese. Since student-agent conversations are realized as role-playing interactions, strong requirements are imposed on the agents ’ affective and social abilities. As a novel feature, social role awareness is introduced to animated conversational agents, that are by now strong affective reasoners, but otherwise often lack the social competence observed with humans. In particular, humans may easily adjust their behavior depending on their respective role in a social setting, whereas their synthetic pendants tend to be driven mostly by emotions and personality. Our main contribution is the incorporation of a ‘social filter program ’ to mental models of animated agents. This program may qualify an agent’s expression of its emotional state by the social context, thereby enhancing the agent’s believability as a conversational partner. Our implemented system is web-based and demonstrates socially aware animated agents in a virtual coffee shop environment. An experiment with our conversation system shows that users consider socially aware agents as more natural than agents that violate conventional practices. | [
558,
1488,
1538,
1723,
2711
] | Validation |
2,537 | 0 | Task-Oriented Dialogs with Animated Agents in Virtual Reality We are working towards animated agents that can carry on tutorial, task-oriented dialogs with human students. The agent's objective is to help students learn to perform physical, procedural tasks, such as operating and maintaining equipment. Although most research on such dialogs has focused on verbal communication, nonverbal communication can play many important roles as well. To allow a wide variety of interactions, the student and our agent cohabit a threedimensional, interactive, simulated mock-up of the student's work environment. The agent, Steve, can generate and recognize speech, demonstrate actions, use gaze and gestures, answer questions, adapt domain procedures to unexpected events, and remember past actions. This paper focuses on Steve's methods for generating multi-modal behavior, contrasting our work with prior work in task-oriented dialogs, multimodal explanation generation, and animated conversational characters. Introduction We are working towards animated agents that... | [
596,
957,
1805,
2992
] | Train |
2,538 | 1 | Least-Squares Temporal Difference Learning TD() is a popular family of algorithms for approximate policy evaluation in large MDPs. TD() works by incrementally updating the value function after each observed transition. It has two major drawbacks: it makes inefficient use of data, and it requires the user to manually tune a stepsize schedule for good performance. For the case of linear value function approximations and = 0, the Least-Squares TD (LSTD) algorithm of Bradtke and Barto (Bradtke and Barto, 1996) eliminates all stepsize parameters and improves data efficiency. This paper extends Bradtke and Barto's work in three significant ways. First, it presents a simpler derivation of the LSTD algorithm. Second, it generalizes from = 0 to arbitrary values of ; at the extreme of = 1, the resulting algorithm is shown to be a practical formulation of supervised linear regression. Third, it presents a novel, intuitive interpretation of LSTD as a model-based reinforcement learning technique. | [
215
] | Train |
2,539 | 3 | Static management of integrity in object-oriented databases: Design and implementation Abstract. In this paper, we propose an efficient technique to statically manage integrity constraints in object-oriented database programming languages. We place ourselves in the context of a simplified database programming language, close to O2, in which we assume that updates are undertaken by means of methods. An important issue when dealing with constraints is that of efficiency. A nave management of such constraints can cause a severe floundering of the overall system. Our basic assumption is that the run-time checking of constraints is too costly to be undertaken systematically. Therefore, methods that are always safe with respect to integrity constraints should be proven so at compile time. The run-time checks should only concern the remaining methods. To that purpose, we propose a new approach, based on the use of predicate transformers combined with automatic theorem proving techniques, to prove the invariance of integrity constraints under complex methods. We then describe the current implementation of our prototype, and report some experiments that have been performed with it on non trivial examples. The counterpart of the problem of program verification is that of program correction. Static analysis techniques can also be applied to solve that problem. We present a systematic approach to undertake the automatic correction of potentially unsafe methods. However, the advantages of the latter technique are not as clear as those of program verification. We will therefore discuss some arguments for and against the use of method correction. 1 | [
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2,540 | 2 | Efficient and Cost-effective Techniques for Browsing and Indexing Large Video Databases We present in this paper a fully automatic content-based approach to organizing and indexing video data. Our methodology involves three steps: ffl Step 1: We segment each video into shots using a Camera-Tracking technique. This process also extracts the feature vector for each shot, which consists of two statistical variances V ar BA and V ar OA . These values capture how much things are changing in the background and foreground areas of the video shot. ffl Step 2: For each video, We apply a fully automatic method to build a browsing hierarchy using the shots identified in Step 1. ffl Step 3: Using the V ar BA and V ar OA values obtained in Step 1, we build an index table to support a variance-based video similarity model. That is, video scenes/shots are retrieved based on given values of V ar BA and V ar OA . The above three inter-related techniques offer an integrated framework for modeling, browsing, and searching large video databases. Our experimental results indic... | [
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2,541 | 1 | Introspective Multistrategy Learning: Constructing a Learnung Strategy under Reasoning Failure Officer praised dog for barking at object." Enables Detect Drugs out FK Initiates Retrieval 5 6 Missing Figure 10. Forgetting to fill the tank with gas A=actual intention; E=expectation; Q=question; C=context; I=index; G=goal Tank Out of Gas Tank Full Tank Low Fill Tank Should have filled up with gas when tank low Expectation What Action to Do? KEY: G = goal; I = index; C = context; Q = question; E = expectation; A = actual intention Results At Store connections with related concepts. Other learning goals take multiple arguments. For instance, a knowledge differentiation goal (Cox & Ram, 1995) is a goal to determine a change in a body of knowledge such that two items are separated conceptually. In contrast, a knowledge reconciliation goal (Cox & Ram, 1995) is one that seeks to merge two items that were mistakenly considered separate entities. Both expansion goals and reconciliation goals may include or spawn a knowledge organization goal (Ram, 1993) that seeks to reorganize the existing knowledge so that it is made available to the reasoner at the appropriate time, as well as modify the structure or content of a concept itself. Such reorganization of knowledge affects the conditions under which a particular piece of knowledge is retrieved or the kinds of indexes associated with an item in memory. | [] | Train |
2,542 | 0 | Dynamic Agent Population in Agent-Based Distance Vector Routing The Intelligent mobile agent paradigm can be applied to a wide variety of intrinsically parallel and distributed applications. Network routing is one such application that can be mapped to an agent-based approach. The performance of any agent-based system will depend on its agent population. Although a lot of research has been conducted on agent-based systems, little consideration has been given to the importance of agent population in dynamic networks. A large number of constituent agents can increase the resource overhead of the system, thereby impeding the overall performance of the network. | [
86,
278
] | Validation |
2,543 | 4 | Broadcasting Consistent Data to Read-Only Transactions from Mobile Clients In this paper, we study the data inconsistency problem in data broadcast to mobile transactions. While data items in a mobile computing system are being broadcast, update transactions may install new values for the data items. If the executions of update transactions and broadcast of data items are interleaved without any control, the transactions generated by mobile clients, called mobile transactions, may observe inconsistent data values. In this paper, we propose a new protocol, called Update-First with Order (UFO), for concurrency control between read-only mobile transactions and update transactions. We show that although the protocol is simple, all the schedules are serializable when the UFO protocol is applied. Furthermore, the new protocol possesses many desirable properties for mobile computing systems such as the mobile transactions do not need to set any lock before they read a data item from the "air" and the protocol can be applied to different broadcast algorithms. Its performance has been investigated with extensive simulation experiment. The results show that the protocol can maximize the freshness of the data items provided to mobile transactions and the broadcast overhead is not heavy especially when the arrival rate of the update transactions is not very high. | [
381,
800,
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] | Test |
2,544 | 0 | Intelligent agents in virtual enterprises Decreasing innovation cycles, changing market situations as well as growing specialisation in individual market segments demand new ways of economic thinking, increasingly forcing enterprises into cooperations, sometimes even with direct competitors. Presently discussed and designated as the corporate and cooperation model of the future is the so-called virtual enterprise. In this paper, we advocate the use of intelligent agents as a useful metaphor and as a software engineering methodology for the design and the operation of virtual enterprises. We focus on how agents can support the cooperative process of setting up virtual enterprises through the Internet by performing tasks such as presentation, information retrieval and extraction, and the participation in auctions in electronic markets. This paper does not describe completed research; it rather offers a perspective of the high potential of agent-based technology for one of tomorrow's key industrial areas by presenting the main objectives of the new research project AVE | [
2364,
2498,
2844,
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] | Test |
2,545 | 2 | Computing the Entropy of User Navigation in the Web Navigation through the web, colloquially known as “surfing”, is one of the main activities of users during web interaction. When users follow a navigation trail they often tend to get disoriented in terms of the goals of their original query and thus the discovery of typical user trails could be useful in providing navigation assistance. Herein we give a theoretical underpinning of user navigation in terms of the entropy of an underlying Markov chain modelling the web topology. We present a novel method for online incremental computation of the entropy and a large deviation result regarding the length of a trail to realise the said entropy. We provide an error analysis for our estimation of the entropy in terms of the divergence between the empirical and actual probabilities. We then indicate applications of our algorithm in the area of web data mining. Finally, we present an extension of our technique to higher-order Markov chains by a suitable reduction of a higher-order Markov chain model to a first-order one. Key words. Web user navigation, Web data mining, navigation problem, Markov chain, entropy 1 | [
1930,
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] | Validation |
2,546 | 0 | On Building Flexible Agents . This paper focuses on the challenge of building technical agents that act exibly in modern computing and information environments. It is argued that existing agent architectures tend to inherently limit an agent's exibility because they imply a discrete social and cognitive behavior space. A generic constraint-centered architectural framework is proposed that aims at enabling agents to act in a continuous behavior space and thus to achieve higher exibility. 1 Introduction Modern computing platforms and information environments are becoming more and more distributed, large, open, dynamic, and heterogeneous. Computers are no longer stand-alone systems, but have become tightly connected both with each other and their users. The increasing technological complexity of such platforms and environments goes together with an increasing complexity of their potential applications. This development has led to a rapidly growing research and application interest in agents as a powerful ... | [
175,
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] | Test |
2,547 | 5 | Learning Maps for Indoor Mobile Robot Navigation Autonomous robots must be able to learn and maintain models of their environments. Research on mobile robot navigation has produced two major paradigms for mapping indoor environments: grid-based and topological. While grid-based methods produce accurate metric maps, their complexity often prohibits efficient planning and problem solving in large-scale indoor environments. Topological maps, on the other hand, can be used much more efficiently, yet accurate and consistent topological maps are often difficult to learn and maintain in large-scale environments, particularly if momentary sensor data is highly ambiguous. This paper describes an approach that integrates both paradigms: grid-based and topological. Grid-based maps are learned using artificial neural networks and naive Bayesian integration. Topological maps are generated on top of the grid-based maps, by partitioning the latter into coherent regions. By combining both paradigms, the approach presented here gains advantages from both worlds: accuracy/consistency and efficiency. The paper gives results for autonomous exploration, mapping and operation of a mobile robot in populated multi-room environments. | [
1286,
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] | Test |
2,548 | 1 | Maintaining Unstructured Case Bases With the dramatic proliferation of case based reasoning systems in commercial applications, many case bases are now becoming legacy systems. They represent a significant portion of an organization's assets, but they are large and difficult to maintain. One of the contributing factors is that these case bases are often large and yet unstructured; they are represented in natural language text. Adding to the complexity is the fact that the case bases are often authored and updated by different people from a variety ofknowledge sources, making it highly likely for a case base to contain redundant and inconsistent knowledge. In this paper, we present methods and a system for maintaining large and unstructured case bases. We focus on two difficult problems in case-base maintenance: redundancy and inconsistency detection. These two problems are particularly pervasive when one deals with an unstructured case base. We will discuss both algorithms and a system for solving these problems. As the ability tocontain the knowledge acquisition problem is of paramount importance, our methods allow one to express relevant domain expertise for detecting both redundancy and inconsistency naturally and effortlessly. Empirical evaluations of the system prove the effectiveness of the methods in several large domains. | [
617,
1844,
2915
] | Train |
2,549 | 4 | A Wearable Computer System with Augmented Reality to Support Terrestrial Navigation To date augmented realities are typically operated in only a small defined area, in the order of a large room. This paper reports on our investigation into expanding augmented realities to outdoor environments. The project entails providing visual navigation aids to users. Awearable computer system with a see-through display, digital compass, and a differential GPS are used to provide visual cues while performing a standard orienteering task. This paper reports the outcomes of a set of trials using an off the shelf wearable computer, equipped with a custom built navigation software package, "map-in-the-hat." | [
1261,
1427,
1719,
2166,
2425,
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2,550 | 3 | Maintaining Transitive Closure of Graphs in SQL It is common knowledge that relational calculus and even SQL are not expressive enough to express recursive queries such as the transitive closure. In a real database system, one can overcome this problem by storing a graph together with its transitive closure and maintaining the latter whenever updates to the former occur. This leads to the concept of an incremental evaluation system, or IES. Much is already known about the theory of IES but very little has been translated into practice. The purpose of this paper is to ll in this gap by providing a gentle introduction to and an overview of some recent theoretical results on IES. The introduction is through the translation into SQL of three interesting positive maintenance results that have practical importance { the maintenance of the transitive closure of acyclic graphs, of undirected graphs, and of arbitrary directed graphs. Interestingly, these examples also allow ustoshow the relationship between power and cost in the incremental maintenance of database queries. 1 | [
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2,551 | 3 | Kaleidoquery: A Visual Query Language for Object Databases In this paper we describe Kaleidoquery, a visual query language for object databases with the same expressive power as OQL. We will describe the design philosophy behind the filter flow nature of Kaleidoquery and present each of the language's constructs, giving examples and relating them to OQL. The Kaleidoquery language is described independent of any implementation details, but a brief description of a 3D interface currently under construction for Kaleidoquery is presented. The queries in this implementation of the language are translated into OQL and then passed to the object database O 2 for evaluation. KEYWORDS: Visual query language, OQL, object databases, three-dimensional interface. INTRODUCTION The lack of a generally accepted and widely supported query language has probably had a significant effect in slowing the uptake of early commercial object-oriented databases. However, the emergence of the Object Query Language (OQL) which is being standardised by the Object Databas... | [
2204,
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2,552 | 5 | A Description Logic with Transitive and Inverse Roles and Role Hierarchies transitive roles play an important rôle in the adequate representation of aggregated objects: they allow these objects to be described by referring to their parts without specifying a level of decomposition. In [Horrocks & Gough, 1997], the Description Logic (DL) ALCH R + is presented, which extends ALC with transitive roles and a role hierarchy. It is argued in [Sattler, 1998] that ALCH R + is well-suited to the representation of aggregated objects in applications that require various part-whole relations to be distinguished, some of which are transitive. For example, a medical knowledge base could contain the following entries defining two different parts of the brain, namely the gyrus and the cerebellum. In contrast to a gyrus, a cerebellum is an integral organ and, furthermore, a functional component of the brain. Hence the role is component (which is a non-transitive sub-role of is part) is used to describe the relation between the brain and the cerebellum: is component ⊑ is part gyrus:= (∀consists.brain mass) ⊓ (∃is part.brain) cerebellum:= organ ⊓ (∃is component.brain) However, ALCH R + does not allow the simultaneous description of parts by means of the whole to which they belong and of wholes by means of their constituent parts: one or other is possible, but not both. To overcome this limitation, we present the DL ALCHI R + which extends ALCH R + with inverse (converse) roles, allowing, for example, the use of has part as well as is part. 1 Using ALCHIR +, we can define a tumorous brain as: tumorous brain:= brain ⊓ (tumorous ⊔ (∃has part.tumorous)) Part of this work was carried out while being a guest at IRST, | [
108,
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] | Train |
2,553 | 0 | Mobile Agents in Distributed Information Retrieval A mobile agent is an executing program that can migrate during execution from machine to machine in a heterogeneous network. On each machine, the agent interacts with stationary service agents and other resources to accomplish its task. Mobile agents are particularly attractive in distributed informationretrieval applications. By moving to the location of an information resource, the agent can search the resource locally, eliminating the transfer of intermediate results across the network and reducing end-toend latency. In this chapter, we rst discuss the strengths of mobile agents, and argue that although none of these strengths are unique to mobile agents, no competing technique shares all of them. Next, after surveying several representative mobile-agent systems, we examine one speci c information-retrieval application, searching distributed collections of technical reports, and consider how mobile agents can be used to implement this application e ciently and easily. Then we spend the bulk of the chapter describing two planning services that allow mobile agents to deal with dynamic network environments and information resources: (1) planning algorithms that let an agent choose the best migration path through the network, given its current task and the current network conditions, and (2) planning algorithms that tell an agent howto observe achanging set of documents in a way that detects changes as soon as possible while minimizing overhead. Finally, we consider the types of errors that can occur when information from multiple sources is merged and ltered, and argue that the structure of a mobile-agent application determines the extent to which these errors a ect the nal result. 1 | [
81,
235,
625,
911,
2310,
2601,
2669,
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] | Validation |
2,554 | 5 | Optimizing Information Agents by Selectively Materializing Data We present an approach for optimizing the performance of information agents by materializing useful information . A critical problem with information agents, particularly those gathering and integrating information from Web sources is a high query response time. This is because the data needed to answer user queries is present across several differentWeb sources (and in several pages within a source) and retrieving,extracting and integrating the data is time consuming. Weaddress this problem by materializing useful classes of information and defining them as auxiliary data sources for the information agent. The key challenge here is to identify the contentandschema of the classes of information that would be useful to materialize. We present an algorithm that identifies such classes by analyzing patterns in user queries. We describe an implementation of our approach and experiments in progress. We also discuss other important problems that we will address in optimizing information agents. | [
1670
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2,555 | 1 | Quality-Based Learning We introduce a methodology for automating the maintenance of domain-specific taxonomies based on natural language text understanding. A given ontology is incrementally updated as new concepts are acquired from real-world texts. The acquisition process is centered around the linguistic and conceptual "quality" of various forms of evidence underlying the generation and refinement of concept hypotheses. On the basis of the quality of evidence, concept hypotheses are ranked according to credibility and the most credible ones are selected for assimilation into the domain knowledge base. Appeared in: ECAII'98 - Proceedings of the 13th Biennial European Conference on Artificial Intelligence/em¿, 23-28 August 1998, Brighton Centre, Brighton, UK.pp.160-164 c fl 1998 ECAI 98. 13th European Conference on Artificial Intelligence Edited by Henri Prade Published in 1998 by John Wiley & Sons, Ltd. Quality-Based Learning Klemens Schnattinger and Udo Hahn 1 Abstract. We introduce a formal model f... | [
2415
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2,556 | 2 | Probe, Count, and Classify: Categorizing Hidden-Web Databases The contents of many valuable web-accessible databases are only accessible through search interfaces and are hence invisible to traditional web "crawlers." Recent studies have estimated the size of this "hidden web" to be 500 billion pages, while the size of the "crawlable" web is only an estimated two billion pages. Recently, commercial web sites have started to manually organize web-accessible databases into Yahoo!-like hierarchical classification schemes. In this paper, we introduce a method for automating this classification process by using a small number of query probes. To classify a database, our algorithm does not retrieve or inspect any documents or pages from the database, but rather just exploits the number of matches that each query probe generates at the database in question. We have conducted an extensive experimental evaluation of our technique over collections of real documents, including over one hundred web-accessible databases. Our experiments show that our system has low overhead and achieves high classification accuracy across a variety of databases. 1. | [
521,
982,
1134,
1432
] | Validation |
2,557 | 5 | Running Across the Reality Gap: Octopod Locomotion Evolved in a Minimal Simulation . This paper describes experiments in which neural network control architectures were evolved in minimal simulation for an octopod robot. The robot is around 30cm long and has 4 infra red sensors that point ahead and to the side, various bumpers and whiskers, and ten ambient light sensors positioned strategically around the body. Each of the robot's eight legs is controlled by two servo motors, one for movement in the horizontal plane, and one for movement in the vertical plane, which means that the robots motors have a total of sixteen degrees of freedom. The aim of the experiments was to evolve neural network control architectures that would allow the robot to wander around its environment avoiding objects using its infra-red sensors and backing away from objects that it hits with its bumpers. This is a hard behaviour to evolve when one considers that in order to achieve any sort of coherent movement the controller has to control not just one or two motors in a coordinated fashion bu... | [
1873,
2047,
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] | Train |
2,558 | 2 | An Overview of World Wide Web Search Technologies With over 800 million pages covering most areas of human endeavor, the World Wide Web is fertile ground for information retrieval. Numerous search technologies have been applied to Web searches, and the dominant search method has yet to be identified. This chapter provides an overview of existing Web search technologies and classifies them into six categories: (i) hyperlink exploration, (ii) information retrieval, (iii) metasearches, (iv) SQL approaches, (v) content-based multimedia searches, and (vi) others. A comparative study of some major commercial and experimental search services is presented, and some future research directions for Web searches are suggested. Keywords: Survey, World Wide Web, Searches, Search Engines, and Information Retrieval. 1. | [
193,
488,
901,
1048,
1321,
1883,
2275,
2419,
2464,
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2,559 | 2 | GeoVIBE: A Visual Interface to Geographic Digital Library This paper explores the possibilities of visualizing document similarities and differences in both spatial and topical domains. Building on previous studies of geographical information retrieval and textual information retrieval (IR) systems, we report on the development of an information browsing tool, GeoVIBE. The system consists of two types of browsing windows, GeoView and VibeView, that work in coordination for visual navigation in the document space. GeoView imposes a geographical order to the document space based on the idea of hypermaps where "icons" and "footprints" may be embedded in maps as the clickable hotspots linking to relevant documents. | [
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2,560 | 2 | Topic-Based Mixture Language Modelling This paper describes an approach for constructing a mixture of language models based on simple statistical notions of semantics using probabilistic models developed for information retrieval. The approach encapsulates corpus-derived semantic information and is able to model varying styles of text. Using such information, the corpus texts are clustered in an unsupervised manner and a mixture of topic-specific language models is automatically created. The principal contribution of this work is to characterise the document space resulting from information retrieval techniques and to demonstrate the approach for mixture language modelling. A comparison is made between manual and automatic clustering in order to elucidate how the global content information is expressed in the space. We also compare (in terms of association with manual clustering and language modelling accuracy) alternative term-weighting schemes and the effect of singular value decomposition dimension reduction (... | [
520,
1726,
2680
] | Validation |
2,561 | 0 | A Model of BDI-Agent in Game-Theoretic Framework . A model of BDI--agent in game--theoretic framework is presented. The desire is represented as agent's goal to achieve a maximum level of utility. A reasoning process based on agent's rational behavior is proposed. This process determines agent's intention. It is also shown how to use the backward induction consistently with the assumption of the common knowledge of rationality. 1 Introduction We are going to discuss the following problem: How does a rational agent use its knowledge in decision making ? Since the problem is general, we put it in a game--theoretic framework. In the theory of games, agent's rationality is understood as a way of maximizing the utility of the agent relatively to its knowledge. The knowledge may concern the game that is to be played as well as the agents participating in a play. The main task of the paper is to model BDI-agent that is supposed to live in the world of dynamic games. Agent's belief is identified with the knowledge about the game and abo... | [
2894
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2,562 | 4 | Adaptive Fuzzy Expert System for Sign Recognition The Hand Motion Understanding (HMU) system is a vision-based Australian sign language recognition system that recognises static and dynamic hand signs. It uses a visual hand tracker to extract 3D hand configuration data from a visual motion sequence, and a classifier that recognises the changes of these 3D kinematic data as a sign. This paper presents the HMU classifier that uses an adaptive fuzzy inference engine for sign recognition. Fuzzy set theory allows the system to express the sign knowledge in natural and imprecise descriptions. The HMU classifier has an adaptive engine that trains the system to be adaptive to the errors caused by the tracker or the motion variations exhibited amongst the signers. The HMU system is evaluated with 22 static and dynamic Auslan signs, and recognised 20 signs before training, and 21 signs after training of the HMU classifier. Keywords: Sign Language, Sign Recognition, Fuzzy Logic, Adaptive Fuzzy System, Expert System. 1. Introduction ... | [
727,
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] | Test |
2,563 | 1 | Will We Have a Wet Summer? Soft Computing Models for Long-term Rainfall Forecasting Long-term rainfall prediction is very important to countries thriving on agro-based economy. In general, climate and rainfall are highly non-linear phenomena in nature giving rise to what is known as "butterfly effect". The parameters that are required to predict the rainfall are enormously complex and subtle so that uncertainty in a prediction using all these parameters is enormous even for a short period. Soft computing is an innovative approach to construct computationally intelligent systems that are supposed to possess humanlike expertise within a specific domain, adapt themselves and learn to do better in changing environments, and explain how they make decisions. Unlike conventional artificial intelligence techniques the guiding principle of soft computing is to exploit tolerance for imprecision, uncertainty, robustness, partial truth to achieve tractability, and better rapport with reality (Zadeh 1998). In this paper, we analysed 87 years of rainfall data in Kerala state, the southern part of Indian Peninsula situated at latitude-longitude pairs (8029 ' N - 76057 ' E). We attempted to train 5 soft computing based prediction models with 40 years of rainfall data. For performance evaluation, network predicted outputs were compared with the actual rainfall data. Simulation results reveal that soft computing techniques are promising and efficient. | [
2450
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2,564 | 1 | Classification on Pairwise Proximity Data We investigate the problem of learning a classification task on data represented in terms of their pairwise proximities. This representation does not refer to an explicit feature representation of the data items and is thus more general than the standard approach of using Euclidean feature vectors, from which pairwise proximities can always be calculated. Our first approach is based on a combined linear embedding and classification procedure resulting in an extension of the Optimal Hyperplane algorithm to pseudo-Euclidean data. As an alternative we present another approach based on a linear threshold model in the proximity values themselves, which is optimized using Structural Risk Minimization. We show that prior knowledge about the problem can be incorporated by the choice of distance measures and examine different metrics w.r.t. their generalization. Finally, the algorithms are successfully applied to protein structure data and to data from the cat's cerebral cortex. They show bette... | [
317
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2,565 | 2 | Inferring Web Communities Through Relaxed Cocitation and Dense Bipartite Graphs Community forming is one of the important activity in the Web. The Web harbors a large number of communities. A community is a group of content creators that manifests itself as a set of interlinked pages. Given a large collection of pages our aim is to find potential communities in the Web. In the literature, Ravi Kumar et al. [18] proposed a trawling method to find potential communities by abstracting a core of the community as a group of pages that form a complete bipartite graph (CBG) (web-page as a node and link as an edge between two nodes). The trawling approach extracts a small group of pages that form a CBG, which is a signature of a potential community. | [
1201,
1838,
1983,
2459,
2503,
3077
] | Validation |
2,566 | 5 | Variorum: A Multimedia-Based Program Documentation System Conventional software documentation systems are mostly based on textutal descriptions that explain or annotate the program's source code. Typically they also support interactive browsing of high-level control flows, and name-based searching of program primitives such as variable declarations and function definitions. Because these systems rely solely on texts, it is difficult for program authors to describe overall algorithm structures and detailed implementation considerations of the programs in an interactive and flexible fashion. Variorum is a novel software documentation system that allows program authors to record the process of "walking through" their own code using multimedia technology, specifically, text, audio, and digital pen drawing. This approach greatly improves the interactivity and flexibility in the software documentation process. In addition, to broaden its applicability and to reduce the implementation complexity, Variorum is designed to inter-operate with the WWW t... | [
2840
] | Train |
2,567 | 4 | Rotating Virtual Objects with Real Handles Times for virtual object rotations reported in the literature are of the order of ten seconds or more and this is far longer than it takes to manually orient a "real" object, such as a cup. This is a report of a series of experiments designed to investigate the reasons for this difference and to help design interfaces for object manipulation. The results suggest that two major factors are important. Having the hand physically in the same location as the virtual object being manipulated is one. The other is based on whether the object is being rotated to a new, randomly determined orientation, or is always rotated to the same position. Making the object held in the hand have the same physical shape as the object being visually manipulated was not found to be a significant factor. The results are discussed in the context of interactive virtual environments. Categories and Subject Descriptors: H.1.2 [Models and Principles]: User/Machine Systems -- human factors; I.3.6 [Computer Graphics]:... | [
1000
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2,568 | 0 | Exploring auction-based leveled-commitment contracting - Part III: Vickrey-type auctioning A key problem addressed in the area of multiagent systems is the automated assignment of multiple tasks to executing agents. The automation of multiagent task assignment requires that the individual agents (i) use a common protocol that prescribes how they have to interact in order to come to an agreement and (ii) fix their final agreement in a contract that specifies the commitments resulting from the assignment on which they agreed. This report describes a novel approach to automated task assignment in multiagent systems that is based on an auction-based protocol and on leveled commitment contracting. This approach is applicable in a broad range of realistic scenarios in which knowledge-intensive negotiation among agents is not feasible and in which future environmental changes may require agents to breach their contracts. 1 Introduction The area of multiagent systems (e.g., [5, 8, 16]), which is concerned with systems composed of technical entities called agents that in... | [
1561,
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] | Validation |
2,569 | 2 | Architecture of a Metasearch Engine that Supports User Information Needs When a query is submitted to a metasearch engine, decisions are made with respect to the underlying search engines to be used, what modifications will be made to the query, and how to score the results. These decisions are typically made by considering only the user's keyword query, neglecting the larger information need. Users with specific needs, such as "research papers" or "homepages," are not able to express these needs in a way that affects the decisions made by the metasearch engine. In this paper, we describe a metasearch engine architecture that considers the user's information need for each decision. Users with different needs, but the same keyword query, may search different sub-search engines, have different modifications made to their query, and have results ordered differently. Our architecture combines several powerful approaches together in a single general purpose metasearch engine. 1 Introduction Current metasearch engines make several decisions on behalf of the use... | [
130,
323,
378,
1048,
1108,
1321,
1352,
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] | Test |
2,570 | 4 | Exploring MARS: Developing Indoor and Outdoor User Interfaces to a Mobile Augmented Reality System We describe an experimental mobile augmented reality system (MARS) testbed that employs different user interfaces to allow outdoor and indoor users to access and manage information that is spatially registered with the real world. Outdoor users can experience spatialized multimedia presentations that are presented on a head-tracked, see-through, head-worn display used in conjunction with a hand-held pen-based computer. Indoor users can get an overview of the outdoor scene and communicate with outdoor users through a desktop user interface or a head- and hand-tracked immersive augmented reality user interface. Key words: Augmented Reality. Wearable Computing. Mobile Computing. Hypermedia. GPS. 1 Introduction As computers increase in power and decrease in size, new mobile and wearable computing applications are rapidly becoming feasible, promising users access to online resources always and everywhere. This new flexibility makes possible a new kind of application---one that exploits ... | [
172,
468,
1598,
2166,
2549
] | Train |
2,571 | 1 | Prediction with Local Patterns using Cross-Entropy Sets of local patterns in the forms of rules and co-occurrence counts are produced by many data mining methods such as association rule algorithms. While such patterns can yield useful insights it is not obvious how to synthesize local sparse information into a coherent global predictive model. We study the use of a cross-entropy approach to combining local patterns. Each local pattern is viewed as a constraint on an appropriate high-order joint distribution of interest. Typically, a set of patterns returned by a data mining algorithm under-constrains the high-order model. The cross-entropy criterion is used to select a specific distribution in this constrained family relative to a prior. We review the iterative-scaling algorithm which is an iterative technique for finding a joint distribution given constraints. We then illustrate the application of this method to two specific problems. The first problem is combining information about frequent itemsets. We show that the cross-entropy a... | [] | Train |
2,572 | 1 | A Cognitive Bias Approach to Feature Selection and Weighting for Case-Based Learners . Research in psychology, psycholinguistics, and cognitive science has discovered and examined numerous psychological constraints on human information processing. Short term memory limitations, a focus of attention bias, and a preference for the use of temporally recent information are three examples. This paper shows that psychological constraints such as these can be used e#ectively as domain-independent sources of bias to guide feature set selection and weighting for case-based learning algorithms. We first show that cognitive biases can be automatically and explicitly encoded into the baseline instance representation: each bias modifies the representation by changing features, deleting features, or modifying feature weights. Next, we investigate the related problems of cognitive bias selection and cognitive bias interaction for the feature weighting approach. In particular, we compare two cross-validation algorithms for bias selection that make di#erent assumptions about the indep... | [
2641,
2823
] | Test |
2,573 | 1 | Selection of Behavioral Parameters: Integration of Discontinuous Switching via Case-Based Reasoning with Continuous Adaptation via Learning Momentum This paper studies the effects of the integration of two learning algorithms, Case-Based Reasoning (CBR) and Learning Momentum (LM), for the selection of behavioral parameters in real-time for robotic navigational tasks. Use of CBR methodology in the selection of behavioral parameters has already shown significant improvement in robot performance [3, 6, 7, 14] as measured by mission completion time and success rate. It has also made unnecessary the manual configuration of behavioral parameters from a user. However, the choice of the library of CBR cases does affect the robot's performance, and choosing the right library sometimes is a difficult task especially when working with a real robot. In contrast, Learning Momentum does not depend on any prior information such as cases and searches for the "right " parameters in real-time. This results in high mission success rates and requires no manual configuration of parameters, but it shows no improvement in mission completion time [2]. This work combines the two approaches so that CBR discontinuously switches behavioral parameters based on given cases whereas LM uses these parameters as a starting point for the real-time search for the "right" parameters. The integrated system was extensively evaluated on both simulated and physical robots. The tests showed that on simulated robots the integrated system performed as well as the CBR only system and outperformed the LM only system, whereas on real robots it significantly outperformed both CBR only and LM only systems. | [
1451
] | Validation |
2,574 | 4 | TouchCounters: Designing Interactive Electronic Labels for Physical Containers We present TouchCounters, an integrated system of electronic modules, physical storage containers, and shelving surfaces for the support of collaborative physical work. Through physical sensors and local displays, TouchCounters record and display usage history information upon physical storage containers, thus allowing access to this information during the performance of real-world tasks. A distributed communications network allows this data to be exchanged with a server, such that users can access this information from remote locations as well. Based upon prior work in ubiquitous computing and tangible interfaces, TouchCounters incorporate new techniques, including usage history tracking for physical objects and multi-display visualization. This paper describes the components, interactions, implementation, and conceptual approach of the TouchCounters system. Keywords Tangible interfaces, ubiquitous computing, distributed sensing, visualization INTRODUCTION For decades, research i... | [
1671,
2452
] | Train |
2,575 | 3 | Query Unnesting in Object-Oriented Databases There is already a sizable body of proposals on OODB query optimization. One of the most challenging problems in this area is query unnesting, where the embedded query can take any form, including aggregation and universal quantification. Although there is already a number of proposed techniques for query unnesting, most of these techniques are applicable to only few cases. We believe that the lack of a general and simple solution to the query unnesting problem is due to the lack of a uniform algebra that treats all operations (including aggregation and quantification) in the same way. This paper presents a new query unnesting algorithm that generalizes many unnesting techniques proposed recently in the literature. Our system is capable of removing any form of query nesting using a very simple and efficient algorithm. The simplicity of the system is due to the use of the monoid comprehension calculus as an intermediate form for OODB queries. The monoid comprehension calculus treats op... | [
653,
1101,
1635,
1879
] | Train |
2,576 | 0 | Abstractions and Infrastructures for the Design and Development of Mobile Agent Organizations Internet applications can take advantage of a paradigm based on autonomous and mobile agents. However, suitable abstractions and infrastructures are required for the effective engineering of such applications. In this paper, we argue that a conceptual framework for context-dependent coordination, supported by an infrastructure based on programmable media, can promote a modular and easy to manage approach to the design and development of mobile agent applications in terms of computational organizations. The MARS coordination infrastructure is presented as an implementation of a coordination infrastructure promoting context-dependent coordination. A case study in the area of workflow management is introduced to clarify the concepts presented. Keywords: Mobile Agents, Agent Organizations, Coordination Infrastructures, Agent-oriented Software Engineering. 1 | [
275,
532,
580,
1022,
1158,
2696
] | Validation |
2,577 | 5 | On Using Regression for Range Data Fusion In the paper, we consider an occupancy-based approach for range data fusion, as it is used in mobile robotics. We identify two major problems of this approach. The first problem deals with the combination rule which in many cases assumes the independence of range data, contrary to the usual situation. The second problem concerns the redundancy of stored and processed data, which results from using the grid representation of the occupancy function and which is the main obstacle to building 3D occupancy world models. We propose a solution to these problems by proposing a new range data fusion technique based on regression. This technique uses the evidence theory in assigning occupancy values, which we argue is advantageous for fusion, and builds the occupancy function by fitting the sample data provided by a sensor with a piecewise linear function. Having developed a general framework for our approach, we apply it to building 3D world models from visual range data, where 3D world models ... | [
250,
1371
] | Train |
2,578 | 3 | VOODOO: A Visual Object-Oriented Database Language for ODMG OQL This paper presents a simple and effective visual language to express ODMG OQL queries. The language is expressive enough to allow most types of query nesting, aggregation, universal and existential quantifications, group-by, and sorting, and at the same time is uniform and very simple to learn and use. Our visual language is strongly typed in the sense that queries constructed in our system are always type-correct. In addition, there is sufficient type information displayed by the system that guides every stage of the query construction. The main difference between our language and other related visual query languages is that we use only one generic visual construct, called a template, instead of inventing a new one for each OQL syntactic feature. 1 Introduction Query and data visualizations are key components of many commercial relational database systems, such as Microsoft Access and Paradox. Object-oriented databases offer excellent opportunities for visual data browsing b... | [
2551
] | Validation |
2,579 | 1 | A Parameter-Less Genetic Algorithm From the user's point of view, setting the parameters of a genetic algorithm (GA) is far from a trivial task. Moreover, the user is typically not interested in population sizes, crossover probabilities, selection rates, and other GA technicalities. He is just interested in solving a problem, and what he would really like to do, is to hand-in the problem to a blackbox algorithm, and simply press a start button. This paper explores the development of a GA that fulfills this requirement. It has no parameters whatsoever. The development of the algorithm takes into account several aspects of the theory of GAs, including previous research works on population sizing, the schema theorem, building block mixing, and genetic drift. | [
773
] | Validation |
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