node_id int64 0 76.9k | label int64 0 39 | text stringlengths 13 124k | neighbors listlengths 0 3.32k | mask stringclasses 4
values |
|---|---|---|---|---|
580 | 0 | LIME: Linda Meets Mobility Lime is a system designed to assist in the rapid development of dependable mobile applications over both wired and ad hoc networks. Mobile agents reside on mobile hosts and all communication takes place via transiently shared tuple spaces distributed across the mobile hosts. The decoupled style of computing characterizing the Linda model is extended to the mobile environment. At the application level, both agents and hosts perceive movement as a sudden change of context. The set of tuples accessible by a particular agent residing on a given host is altered transparently in response to changes in the connectivity pattern among the mobile hosts. In this paper we present the key design concepts behind the Lime system. 1 INTRODUCTION Today's users demand ubiquitous network access independent of their physical location. This style of computation, often referred to as mobile computing, is enabled by rapid advances in the wireless communication technology. The networking scenarios enabled ... | [
102,
532,
686,
811,
1225,
1353,
1749,
1795,
2150,
2576,
2626,
2844
] | Train |
581 | 2 | A Layered Approach towards Domain Authoring Support This paper presents an approach to authoring support for Web courseware based on a layered ontological paradigm. The ontology-based layers in the courseware authoring architecture serve as a basis for formal semantics and reasoning support in performing generic authoring tasks. This approach represents an extension of our knowledge classification and indexing mechanism from a previously developed system, AIMS, aimed at supporting students while completing learning tasks in a Web-based learning/training environment. We propose the addition of two vertical layers in the system architecture, Author assisting layer and Operational layer, with the role of facilitating the creation of the ontological layers (Course ontology and Domain ontology) and of the educational metadata layer. Here we focus on the domain ontology creation process, together with the support that the additional layers can provide within this process. We exemplify our method by presenting a set of generic tasks related to conceptbased domain authoring and their ontological support | [
3125
] | Train |
582 | 2 | Scaling Question Answering to the Web The wealth of information on the web makes it an attractive resource for seeking quick answers to simple, factual questions such as “who was the first American in space? ” or “what is the second tallest mountain in the world? ” Yet today’s most advanced web search services (e.g., Google and AskJeeves) make it surprisingly tedious to locate answers to such questions. In this paper, we extend question-answering techniques, first studied in the information retrieval literature, to the web and experimentally evaluate their performance. First we introduce MULDER, which we believe to be the first general-purpose, fully-automated question-answering system available on the web. Second, we describe MULDER’s architecture, which relies on multiple search-engine queries, natural-language parsing, and a novel voting procedure to yield reliable answers coupled with high recall. Finally, we compare MULDER’s performance to that of Google and AskJeeves on questions drawn from the TREC-8 question answering track. We find that MULDER’s recall is more than a factor of three higher than that of AskJeeves. In addition, we find that Google requires 6.6 times as much user effort to achieve the same level of recall as MULDER. | [
1136,
2822
] | Test |
583 | 2 | Heterogeneous Multimedia Database Selection on the Web Multimedia databases on the Web have two distinct characteristics, autonomy and heterogeneity. They are established and maintained independently and queries are processed depending on their own schemes. In this paper, we investigate the problem of the database selection from a number of multimedia databases dispersed on the Web. In the multimedia objects retrieval from distributed sites, it is crucial that the metaserver has the capability to find objects, globally similar to a given query object, from different multimedia databases with different local similarity measures. We propose a novel selection algorithm to determine candidate databases that contain more objects relevant to the query than other databases. The selection of databases is based on the number of relevant objects at each local database that is estimated by using a few sample objects and the histogram information. An extensive experiment on a large number of real data sets demonstrates that our proposed method perform... | [
270,
629,
1120,
1642,
1824
] | Test |
584 | 5 | Data-Driven Generation of Compact, Accurate, and Linguistically-Sound Fuzzy Classifiers Based on a Decision-Tree Initialization The data-driven identification of fuzzy rule-based classifiers for high-dimensional problems is addressed. A binary decision-tree-based initialization of fuzzy classifiers is proposed for the selection of the relevant features and e#ective initial partitioning of the input domains of the fuzzy system. Fuzzy classifiers have more flexible decision boundaries than decision trees (DTs) and can therefore be more parsimonious. Hence, the decision tree initialized fuzzy classifier is reduced in an iterative scheme by means of similarity-driven rule-reduction. To improve classification performance of the reduced fuzzy system, a genetic algorithm with a multi-objective criterion searching for both redundancy and accuracy is applied. The proposed approach is studied for (i) an artificial problem, (ii) the Wisconsin Breast Cancer classification Preprint submitted to Elsevier Science 19 May 2002 problem, and (iii) a summary of results is given for a set of well-known classification problems available from the Internet: Iris, Ionospehere, Glass, Pima, and Wine data. | [
735,
1984,
3026
] | Train |
585 | 2 | Evolution of the Walden's Paths Authoring Tools : Changing user skills, available infrastructure, and work practices have caused many differences in the authoring support provided by the Walden's Paths project since its conception. In this paper we trace these changes and the transition from the earlier authoring tools that supported an integrated authoring process, to the more recent tools designed to work with the Web applications that teachers have become accustomed to. 1. Introduction Hypertext has come a long way from being found only in research systems to being a part of our everyday lives in the form of the World-Wide Web (WWW or the Web). We use the Web for browsing academic information, for furthering business interests, for entertainment and a variety of other purposes. There is an immense amount of information on the Web that can be used for a variety of reasons. Web-based information can be harnessed to supplement classroom teaching for K-12 students. K-12 teachers can use Web-based information in the curriculum t... | [
1211
] | Validation |
586 | 2 | A Layered Approach To Nlp-Based Information Retrieval A layered approach to information retrieval permits the inclusion of multiple search engines as well as multiple databases, with a natural language layer to convert English queries for use by the various search engines. The NLP layer incorporates morphological analysis, noun phrase syntax, and semantic expansion based on WordNet. 1 Introduction This paper describes a layered approach to information retrieval, and the natural language component that is a major element in that approach. The layered approach, packaged as Intermezzo TM , was deployed in a pre-product form at a government site. The NLP component has been installed, with a proprietary IR engine, PhotoFile, (Flank, Martin, Balogh and Rothey, 1995), (Flank, Garfield, and Norkin, 1995), at several commercial sites, including Picture Network International (PNI), Simon and Schuster, and John Deere. Intermezzo employs an abstraction layer to permit simultaneous querying of multiple databases. A user enters a query into a clien... | [
370,
1442
] | Train |
587 | 2 | Finding the Most Similar Documents across Multiple Text Databases In this paper, we present a methodology for finding the n most similar documents across multiple text databases for any given query and for any positive integer n. This methodology consists of two steps. First, databases are ranked in a certain order. Next, documents are retrieved from the databases according to the order and in a particular way. If the databases containing the n most similar documents for a given query can be ranked ahead of other databases, the methodology will guarantee the retrieval of the n most similar documents for the query. A statistical method is provided to identify databases, each of which is estimated to contain at least one of the n most similar documents. Then, a number of strategies is presented to retrieve documents from the identified databases. Experimental results are given to illustrate the relative performance of different strategies. 1 Introduction The Internet has become a vast information source in recent years and can be considered as the w... | [
488,
976,
982,
1059,
1120,
1134,
1167,
1642,
1804,
1888,
2188,
2275,
2771,
2920,
3139
] | Train |
588 | 5 | Learning to Perceive the World as Articulated: An Approach for Hierarchical Learning in Sensory-Motor Systems This paper describes how agents can learn an internal model of the world structurally by focusing on the problem of behavior-based articulation. We develop an on-line learning scheme -- the so-called mixture of recurrent neural net (RNN) experts -- in which a set of RNN modules becomes self-organized as experts on multiple levels in order to account for the different categories of sensory-motor flow which the robot experiences. Autonomous switching of activated modules in the lower level actually represents the articulation of the sensory-motor flow. In the meanwhile, a set of RNNs in the higher level competes to learn the sequences of module switching in the lower level, by which articulation at a further more abstract level can be achieved. The proposed scheme was examined through simulation experiments involving the navigation learning problem. Our dynamical systems analysis clarified the mechanism of the articulation; the possible correspondence between the articulation... | [
149,
722
] | Validation |
589 | 0 | Integrating Mobile Agents into Off-the-Shelf Web Servers: The M&M Approach The mobile agent paradigm provides a new approach for developing distributed systems. During the last two years, we have been working on a project that tries to overcome some of the limitations found in terms of programmability and usability of the mobile agent paradigm in real applications. In the M&M framework there are no agent platforms. Instead applications become agent-enabled by using simple JavaBeans components. In our approach the agents arrive and departure directly from the applications, interacting with them from the inside. | [
2099,
2128,
2224
] | Test |
590 | 2 | Flexible Queries to Semi-structured Datasources: the WG-log Approach A line of research is presented aimed at specifying both logical and navigational aspects of semi-structured data sources such as Web sites through the unifying notion of schema. Gracefully supporting schemata that are huge or subject to change, the WG-Log language allows for a uniform representation of queries and views, the latter expressing customized access structures to site information. A survey of related work and some directions for future research involving fuzzy query techniques are also outlined. 1 Introduction and Motivations Modern network-oriented information systems often have to deal with data that are semi-structured, i.e. lack the strict, regular, and complete structure required by traditional database management systems (see [Abi97] and [Suc97] for a survey on semi-structured data and related research). Information is semi-structured also when the structure of data varies w.r.t. time, rather than w.r.t. space: even if data is fairly well structured, such struc... | [
513
] | Validation |
591 | 4 | Learning Task Models for Collagen For an application-independent collaborative tool, a key step is to develop a detailed task model for a particular domain. This is a time consuming and dicult task, and seems to require a fairly advanced knowledge of AI representations for plans, goals, and recipes. This paper discusses some preliminary ideas for making it easier to construct and evolve task models, either through interaction with a human domain expert, through machine learning, or in a mixed-initiative system. Introduction An important trend in recent work on human-computer interaction and user modeling has been to view humancomputer interaction as a kind of collaboration. In this approach, the human user and the computer, often personied as an \agent," coordinate their actions toward achieving shared goals. Collagen is an application-independent collaboration manager based on the SharedPlan theory of task-oriented collaborative discourse (Grosz & Sidner, 1990; Rich & Sidner, 1998; Lesh, Rich, & Sidner, 199... | [
109
] | Train |
592 | 2 | A Dynamic Replica Selection Algorithm for Tolerating Timing Faults Server replication is commonly used to improve the fault tolerance and response time of distributed services. An important problem when executing time-critical applications in a replicated environment is that of preventing timing failures by dynamically selecting the replicas that can satisfy a client's timing requirement, even when the quality of service is degraded due to replica failures and excess load on the server. In this paper, we describe the approach we have used to solve this problem in AQuA, a CORBA-based middleware that transparently replicates objects across a local area network. The approach we use estimates a replica's response time distribution based on performance measurements regularly broadcast by the replica. An online model uses these measurements to predict the probability with which a replica can prevent a timing failure for a client. A selection algorithm then uses this prediction to choose a subset of replicas that can together meet the client's timing constraints with at least the probability requested by the client. We conclude with experimental results based on our implementation. | [
2973
] | Train |
593 | 1 | Using Knowledge Containers to Model a Framework for Learning Adaptation Knowledge In this paper we present a framework for learning adaptation knowledge which knowledge light approaches for case-based reasoning (CBR) systems. Knowledge light means that these approaches use already acquired knowledge inside the CBR system. Therefor we describe the sources of knowledge inside a CBR system along the different knowledge containers. After that we present our framework in terms of these knowledge containers. Further we apply our framework in a case study to one knowledge light approach for learning adaptation knowledge. After that we point on some issues which should be addressed during the design or the use of such algorithms for learning adaptation knowledge. From our point of view many of these issues should be the topic of further research. Finally we close with a short discussion and an outlook to further work. | [
1424
] | Test |
594 | 3 | Real-Time Index Concurrency Control Real-time database systems are expected to rely heavily on indexes to speed up data access and thereby help more transactions meet their deadlines. Accordingly, highperformance index concurrency control (ICC) protocols are required to prevent contention for the index from becoming a bottleneck. In this paper, we develop real-time variants of a representative set of classical B-tree ICC protocols and, using a detailed simulation model, compare their performance for real-time transactions with firm deadlines. We also present and evaluate a new real-time ICC protocol called GUARD-link that augments the classical B-link protocol with a feedback-based admission control mechanism. Both point and range queries, as well as the undos of the index actions of aborted transactions are included in the scope of our study. The performance metrics used in evaluating the ICC protocols are the percentage of transactions that miss their deadlines and the fairness with respect to transaction type and size... | [] | Train |
595 | 3 | Flow Analysis for Verifying Specifications of Concurrent and Distributed Software This paper presents FLAVERS, a finite state verification approach that analyzes whether concurrent or sequential programs satisfy user-defined correctness properties. In contrast to other finite-state verification techniques, FLAVERS is based on algorithms with low-order polynomial bounds on the running time. FLAVERS achieves this efficiency at the cost of precision. Users, however, can improve the precision of the results by selectively and judiciously incorporating additional semantic information into the analysis problem. The FLAVERS analysis approach has been implemented for programs written in Ada. We report on an empirical study of the performance of applying the FLAVERS/Ada tool set to a collection of multi-tasking Ada programs. This study indicates that sufficient precision for proving program properties can be achieved and that the cost for such analysis grows as a low-order polynomial in the size of the program. 1 Introduction The application of distributed and concurrent pr... | [
913
] | Train |
596 | 0 | Evaluating Humanoid Synthetic Agents in E-Retail Applications This paper presents three experiments designed to empirically evaluate humanoid synthetic agents in electronic retail applications. Firstly, human-like agents were evaluated in a single e-retail application, a home furnishings service. The second experiment explored application dependency effects by evaluating the same human-like agents in a different e-retail application, a personalized CD service. The third experiment evaluated the effectiveness of a range of humanoid cartoon-like agents. Participants eavesdropped on spoken dialogues between a "customer" and each of the agents, which played the role of conversational sales assistants. Results showed participants expected a high level of realistic human-like verbal and nonverbal communicative behavior from the human-like agents. Overall ratings of the agents showed no significant application dependency: Two different groups of participants rated the human-like agents in similar ways in a different application. Further results showed participants have a preference for three--dimensional (3-D) rather than two--dimensional (2-D) cartoon-like agents and have a desire to interact with fully embodied agents. I. | [
2537
] | Validation |
597 | 2 | Towards Transparent Control of Large and Complex Systems System Identi cation. Unlike with Markovian Decision Processes, some systems' output depends not only on the current state, but also the previous input/output. As a training data set for nonlinear system identi cation, the Box-Jenkins gas furnace data [BJ70] is often studied and compared. The furnace input is the gas ow rate x(t), the output y(t) is the CO 2 concentration. At least 10 candidate inputs are considered: x(t 6); x(t 5); : : : ; x(t 1); y(t 1); : : : ; y(t 4). If all of them are used, building a fuzzy controller means to solve a 10-input-1-output problem. If each input is de ned by 5 linguistic terms, this would result in a fuzzy rule system of about 10 million rules. The modelling and prediction o | [
455
] | Train |
598 | 4 | Audio Driven Facial Animation For Audio-Visual Reality In this paper, we demonstrate a morphing based automated audio driven facial animation system. Based on an incoming audio stream, a face image is animated with full lip synchronization and expression. An animation sequence using optical flow between visemes is constructed, given an incoming audio stream and still pictures of a face speaking different visemes. Rules are formulated based on coarticulation and the duration of a viseme to control the continuity in terms of shape and extent of lip opening. In addition to this new viseme-expression combinations are synthesized to be able to generate animations with new facial expressions. Finally various applications of this system are discussed in the context of creating audio-visual reality. 1. | [
2189
] | Train |
599 | 4 | Augmented Reality: Which Augmentation for Which Reality? In this paper, we first present a brief review of approaches used for studying and designing Augmented Reality (AR) systems. The variety of approaches and definitions in AR requires classification. We define two intrinsic characteristics of AR systems, task focus and nature of augmentation. Based on these two characteristics, we identify four classes of AR systems. In addition our OP-a-S notation provides a complementary characterization method based on interaction. Using OP-a-S, an AR system is modeled as a set of components that communicate with each other. One crucial type of OP-a-S component is the Adapter that establishes a bridge between the real world and the virtual world. By defining a classification scheme, we aim at providing a better understanding of the paradigm of AR and at laying the foundations of future design principles according to the class of systems. Keywords Classification. Interaction characterization. INTRODUCTION One of the recent design goals in Human Com... | [
675
] | Validation |
600 | 0 | Meeting Plan Recognition Requirements for Real-Time Air-Mission Simulations In this paper, the potential synergy between instancebased pattern recognition and means-end (possible world) reasoning is explored, for supporting plan recognition in multi-aeroplane air-mission simulations. A combination of graph matching, induction, probabilistic principles and dynamic programming are applied to traces of aeroplane behaviour during flight manoeuvres. These satisfy the real-time constraints of the simulation. This enables the agents to recognise what other agents are doing and to abstract about their activity, at the instrumentation level. A means-end-reasoning model is then used to deliberate about and invoke standard operating procedures, based on recognised activity. The reasoning model constrains the recognition process by framing queries according to what a pilot would expect during the execution of the current plan(s). Results from experiments involving the dMARS procedural reasoning system and the CLARET pattern matching and induction system are described for ... | [
485,
881,
2364
] | Test |
601 | 1 | Accelerating Reinforcement Learning through the Discovery of Useful Subgoals An ability to adjust to changing environments and unforeseen circumstances is likely to be an important component of a successful autonomous space robot. This paper shows how to augment reinforcement learning algorithms with a method for automatically discovering certain types of subgoals online. By creating useful new subgoals while learning, the agent is able to accelerate learning on a current task and to transfer its expertise to related tasks through the reuse of its ability to attain subgoals. Subgoals are created based on commonalities across multiple paths to a solution. We cast the task of finding these commonalities as a multiple-instance learning problem and use the concept of diverse density to find solutions. We introduced this approach in [10] and here we present additional results for a simulated mobile robot task. 1 | [
2967
] | Test |
602 | 3 | Alternative Correctness Criteria for Multiversion Concurrency Control and a Locking Protocol via Freezing Concurrency control protocols based on multiversions have been used in some commercial transaction processing systems in order to provide the serializable executions of transactions. In the existing protocols, transactions are allowed to read only the most recent version of each data item in order to ensure the correct execution of transactions. However, this feature is not desirable in some advanced database systems which have more requirements such as timing or security constraints besides serializability. In this paper, we propose a new correctness criteria, called F-serializability, for multiversion concurrency control protocols. It is the extended definition of `1-serial' and relaxes the condition so that a protocol provides not only the most recent version but also the previous one to transactions, if necessary. We prove that whenever a multiversion schedule is F-serializable, the schedule is also one-copy serializable. This is the first contribution of our paper. Next, we propos... | [
1047
] | Train |
603 | 1 | Learning Hidden Markov Model Structure for Information Extraction Statistical machine learning techniques, while well proven in fields such as speech recognition, are just beginning to be applied to the information extraction domain. We explore the use of hidden Markov models for information extraction tasks, specifically focusing on how to learn model structure from data and how to make the best use of labeled and unlabeled data. We show that a manually-constructed model that contains multiple states per extraction field outperforms a model with one state per field, and discuss strategies for learning the model structure automatically from data. We also demonstrate that the use of distantly-labeled data to set model parameters provides a significant improvement in extraction accuracy. Our models are applied to the task of extracting important fields from the headers of computer science research papers, and achieve an extraction accuracy of 92.9%. Introduction Hidden Markov modeling is a powerful statistical machine learning technique that is just ... | [
836,
1108,
1294,
1478,
2104,
2133,
2342,
2371,
2765,
3098,
3152
] | Validation |
604 | 0 | Agent Aided Aircraft Maintenance Aircraft maintenance is performed bymechanics who are required, for non-standard discrepancies, to consult expert engineers for repair instructions and approval. In addition to their own experience, these engineers rely on external information sources, which are often inadequately indexed and geographically dispersed. The timely retrieval of this distributed information is essencial to the engineers' abilityto devise and recommend repair procedures in response to the mechanics ' requests. This problem domain is well suited for a multi-agent system: it consists of distributed multi-modal information whichis needed bymultiple users with diverse preferences. In this paper, we describe an implementation of such a system, using the RETSINA multi-agentarchitecture. Such an implementation reinforces the importance of multi-agent systems, and in particular the usefulness of the RETSINA infrastructure as a basis for the construction of such systems. i 1 Introduction Agent aided... | [
2230
] | Train |
605 | 2 | Data Mining on Symbolic Knowledge Extracted from the Web Information extractors and classifiers operating on unrestricted, unstructured texts are an errorful source of large amounts of potentially useful information, especially when combined with a crawler which automatically augments the knowledge base from the world-wide web. At the same time, there is much structured information on the World Wide Web. Wrapping the web-sites which provide this kind of information provide us with a second source of information; possibly less up-to-date, but reliable as facts. We give a case study of combining information from these two kinds of sources in the context of learning facts about companies. We provide results of association rules, propositional and relational learning, which demonstrate that data-mining can help us improve our extractors, and that using information from two kinds of sources improves the reliability of data-mined rules. 1. INTRODUCTION The World Wide Web has become a significant source of information. Most of this computer-retri... | [
301,
721,
759,
1085,
1782,
2750
] | Train |
606 | 0 | Building Cognitively Rich Agents Using The Sim Agent Toolkit Synthetic agents with varying degrees of intelligence and autonomy are being designed in many research laboratories. The motivations include military training simulations, games and entertainments, educational software, digital personal assistants, software agents managing Internet transactions or purely scientific curiosity. Different approaches are being explored, including, at one extreme, research on the interactions between agents, and at the other extreme research on processes within agents. The first approach focuses on forms of communication, requirements for consistent collaboration, planning of coordinated behaviours to achieve collaborative goals, extensions to logics of action and belief for multiple agents, and types of emergent phenomena when many agents interact, for instance taking routing decisions on a telecommunications network. The second approach focuses on the internal architecture of individual agents required for social interaction, collaborative behaviours, complex decision making, learning, and emergent phenomena within complex agents. Agents with complex internal structure may, for example, combine perception, motive generation, planning, plan execution, execution monitoring, and even emotional reactions. | [
1275,
3179
] | Validation |
607 | 3 | Stratum Approaches to Temporal DBMS Implementation database interfaces, legacy systems. Previous approaches to implementing temporal DBMSs have assumed that a temporal DBMS must be built from scratch, employing an integrated architecture and using new temporal implementation techniques such as temporal indexes and join algorithms. However, this is a very large and time-consuming task. This paper explores approaches to implementing a temporal DBMS as a stratum on top of an existing non-temporal DBMS, rendering implementation more feasible by reusing much of the functionality of the underlying conventional DBMS. More specifically, the paper introduces three stratum meta-architectures, each with several specific architectures. Based on a new set of evaluation criteria, advantages and disadvantages of the specific architectures are identified. The paper also classifies all existing temporal DBMS implementations according to the specific architectures they employ. It is concluded that a stratum architecture is the best short, medium, and perhaps even longterm, approach to implementing a temporal DBMS. 1 | [
10,
1254
] | Test |
608 | 2 | Evaluating Topic-Driven Web Crawlers Due to limited bandwidth, storage, and computational resources, and to the dynamic nature of the Web, search engines cannot index every Web page, and even the covered portion of the Web cannot be monitored continuously for changes. Therefore it is essential to develop effective crawling strategies to prioritize the pages to be indexed. The issue is even more important for topic-specific search engines, where crawlers must make additional decisions based on the relevance of visited pages. However, it is difficult to evaluate alternative crawling strategies because relevant sets are unknown and the search space is changing. We propose three different methods to evaluate crawling strategies. We apply the proposed metrics to compare three topic-driven crawling algorithms based on similarity ranking, link analysis, and adaptive agents. | [
2,
116,
553,
825,
848,
1512,
1838,
2471,
2610,
3170
] | Train |
609 | 3 | Scalable Consistency Protocols for Distributed Services AbstractÐA common way to address scalability requirements of distributed services is to employ server replication and client caching of objects that encapsulate the service state. The performance of such a system could depend very much on the protocol implemented by the system to maintain consistency among object copies. We explore scalable consistency protocols that never require synchronization and communication between all nodes that have copies of related objects. We achieve this by developing a novel approach called local consistency (LC). LC based protocols can provide increased flexibility and efficiency by allowing nodes control over how and when they become aware of updates to cached objects. We develop two protocols for implementing strong consistency using this approach and demonstrate that they scale better than a traditional invalidation based consistency protocol along the system load and geographic distribution dimensions of scale. Index TermsÐScalable services, distributed objects, replication, caching, consistency protocols. 1 | [
1686
] | Train |
610 | 3 | Query Optimization for Selections using Bitmaps Bitmaps are popular indexes for data warehouse (DW) applications and most database management systems offer them today. This paper proposes query optimization strategies for selections using bitmaps. Both continuous and discrete selection criteria are considered. Query optimization strategies are categorized into static and dynamic. Static optimization strategies discussed are the optimal design of bitmaps, and algorithms based on tree and logical reduction. The dynamic optimization discussed is the approach of inclusion and exclusion for both bit-sliced indexes and encoded bitmap indexes. 1 Introduction Bitmap indexing has become a promising technique for query processing in DWs. Variations of bitmap indexes include bit-sliced indexes [14, 3], encoded bitmap indexes (EBI) [18], bitmapped join indexes [13], range-based bitmap indexes [20], and others[16]. For query operations, such as selections, aggregates, and joins, query evaluation algorithms using bitmaps have been proposed in ... | [
1934,
2293
] | Train |
611 | 4 | Construction of Adaptive Web-Applications from Reusable Components . The Web has become a ubiquitous environment for application | [
1696
] | Train |
612 | 2 | Using Error-Correcting Codes For Text Classification This paper explores in detail the use of Error Correcting Output Coding (ECOC) for learning text classifiers. We show that the accuracy of a Naive Bayes Classifier over text classification tasks can be significantly improved by taking advantage of the error-correcting properties of the code. We also explore the use of different kinds of codes, namely Error-Correcting Codes, Random Codes, and Domain and Data-specific codes and give experimental results for each of them. The ECOC method scales well to large data sets with a large number of classes. Experiments on a real-world data set show a reduction in classification error by up to 66% over the traditional Naive Bayes Classifier. We also compare our empirical results to semitheoretical results and find that the two closely agree. 1. Introduction Text Classification is the problem of grouping text documents into classes or categories. For the purpose of this paper, we define classification as categorizing documents in... | [
526,
993
] | Train |
613 | 0 | Using Mobile Agents to implement flexible Network Management strategies Due to their intrinsic complexity, computer and communication systems require increasingly more sophisticated management starategies to be adopted in order to guarantee adequate levels of performance and reliability. The centralized paradigm adopted by the SNMP is appropriate in several network management applications, but the quick expansion of networks has posed the problem of its scalability, as well as for any other centralized model. Mobile agents represent a challenging approach to provide advanced network management functionalities, due to the possibility to easily implement a decentralized and active monitoring of the system. In this paper we discuss how to take advantage of this technology and identify some reference scenario where mobile agents represent a very promising approach. We also describe a prototype implementation based on our mobile agent platform called MAP and show how it is possible to take advantages from using the features it provides. Keywords: net... | [
685
] | Train |
614 | 0 | Socialware: Multiagent Systems for Supporting Network Communities ing with credit is permitted. To copy otherwise, to republish, to post on servers, or to redistribute to lists, requires prior specific permission and/or a fee. Request permissions from Publications Dept, ACM Inc., fax +1 (212) 869-0481, or permissions@acm.org. Community B Community A Community C Community agent A1 Community agent B1 Community agent B2 Personal unit 1 Personal unit 2 Personal unit 5 Personal unit 6 Personal unit 3 Personal unit 7 Personal unit 4 User 5 to join User 4 to leave Figure 1: A general architecture of socialware as a multiagent system Socialware as Multiagent Systems There are several characteristics specific to network communities, which make a multiagent architecture attractive to use. The first characteristic is that the participants of a network community are widely distributed and the number of potential participants is large. Hence, no solid, centralized, or monolithic system would be adequate: A distributed system would be required, in which perso... | [
2279,
2870
] | Train |
615 | 0 | Updating Mental States from Communication . In order to perform effective communication agents must be able to foresee the effects of their utterances on the addressee's mental state. In this paper we investigate on the update of the mental state of an hearer agent as a consequence of the utterance performed by a speaker agent. Given an agent communication language with a STRIPSlike semantics, we propose a set of criteria that allow to bind the speaker's mental state to its uttering of a certain sentence. On the basis of these criteria, we give an abductive procedure that the hearer can adopt to partially recognize the speaker's mental state that led to a specific utterance. This procedure can be adopted by the hearer to update its own mental state and its image of the speaker's mental state. 1 Introduction In multi-agent systems, communication is necessary for the agents to cooperate and coordinate their activities or simply to avoid interfering with one another. If agents are not designed with embedded pre-compiled... | [
1922,
2364
] | Train |
616 | 2 | Preserving Contextual Navigation in Hypermedia Querying Navigating query results is a highly volatile task, usually requiring much effort from the users, while not providing a firm reference point for further queries or refinement. Many users accessing traditional search engines are confronted with lengthy pages of hypertext links, through which relevant information must be found. Accessing each link can bring a user closer or farther from the information they seek; in either case, the context between the query results and the current web page can be lost. Delaunay MM addresses these issues by creating virtual documents through which all query results are displayed in a meaningful and organized fashion; and that reference the originating web page, thus providing semantic browsing and hypermedia navigation without loss of context. Keywords: Digital Library Querying, Hypermedia Querying, Context Preservation Introduction With an increase in the number of users daily, the World Wide Web has become one of the most indispensable technologie... | [
2031
] | Train |
617 | 5 | Supporting Dialogue Inferencing in Conversational Case-Based Reasoning . Dialogue inferencing is the knowledge-intensive process of inferring aspects of a user's problem from its partial description. Conversational case-based reasoning (CCBR) systems, which interactively and incrementally elicit a user's problem description, suffer from poor retrieval efficiency (i.e., they prompt the user with questions that the user has already implicitly answered) unless they perform dialogue inferencing. The standard method for dialogue inferencing in CCBR systems requires library designers to supply explicit inferencing rules. This approach is problematic (e.g., maintenance is difficult). We introduce an alternative approach in which the CCBR system guides the library designer in building a domain model. This model and the partial problem description are then given to a query retrieval system (PARKA-DB) to infer any implied answers during a conversation. In an initial empirical evaluation in the NaCoDAE CCBR tool, our approach improved retrieval efficiency without sa... | [
2548,
2915
] | Test |
618 | 4 | A Wearable 3D Augmented Reality Workspace This poster describes our work to build a wearable Augmented Reality system that supports true stereoscopic 3D graphics. Through a pen and pad interface well known 2D user interfaces can be presented to the user, whereas the tracking of the pen allows to use direct interaction with virtual objects. The system is assembled from off-the-shelf hardware components and serves as a basic test bed for user interface experiments related to collaboration between stationary and mobile AR users. 1. | [
172,
468,
2365
] | Test |
619 | 3 | An Architecture and Object Model for Distributed Object-Oriented Real-Time Databases The confluence of computers, communications, and databases is quickly creating a distributed database where many applications require real-time access to both temporally accurate and multimedia data. This is particularly true in military and intelligence applications, but these required features are needed in many commercial applications as well. We are developing a distributed database, called BeeHive, which could offer features along different types of requirements: real-time, fault-tolerance, security, and quality-of service for audio and video. Support of these features and potential trade-offs between them could provide a significant improvement in performance and functionality over current distributed database and object management systems. In this paper, we present a high level design for BeeHive architecture and sketch the design of the BeeHive Object Model (BOM) which extends object-oriented data models by incorporating time and other features into objects, resulting in a high... | [
578
] | Validation |
620 | 0 | A Conceptual Framework for Agent Definition and Development The use of agents of many different kinds in a variety of fields of computer science and artificial intelligence is increasing rapidly and is due, in part, to their wide applicability. The richness of the agent metaphor that leads to many different uses of the term is, however, both a strength and a weakness: its strength lies in the fact that it can be applied in very many different ways in many situations for different purposes; the weakness is that the term agent is now used so frequently that there is no commonly accepted notion of what it is that constitutes an agent. This paper addresses this issue by applying formal methods to provide a defining framework for agent systems. The Z specification language is used to provide an accessible and unified formal account of agent systems, allowing us to escape from the terminological chaos that surrounds agents. In particular, the framework precisely and unambiguously provides meanings for common concepts and terms, enables alternative models of particular classes of system to be described within it, and provides a foundation for subsequent development of increasingly more refined concepts. | [
1054,
2030,
2192,
2343,
3076
] | Train |
621 | 4 | Principles for a Usability-Oriented Pattern Language High-level usability principles (e.g. "Familiarity") are difficult to apply to specific projects, and style guides providing more detailed instructions are often misinterpreted and inaccessible. An approach to usability based on design patterns enables designers to learn how certain recurring problems can be solved according to high-level principles. This paper summarises a review of the desirable properties advocated by five popular style guides, and discusses how this list has been modified to provide an underlying philosophy which is appropriate for a usability-oriented pattern language. A sample pattern which exemplifies this philosophy, involving iteration through selectable objects, is described. KEYWORDS Usability engineering, Design techniques, Style guides. 1. Introduction There has been considerable discussion about how to reconcile the gaps between software engineering (SE) and human-computer interaction (HCI). One of the primary ways to smoothly integrate the disciplines ... | [
517,
3185
] | Test |
622 | 0 | Controlling Speculative Computation in Multi-Agent Environments In this paper, we propose a multi-agent system which performs speculative computation under incomplete communication environments. In a master-slave style multi-agent system with speculative computation, a master agent asks queries to slave agents in problem solving, and proceeds computation with default answers when answers from slave agents are delayed. We rst provide a semantics for speculative computation using default logic. Then, in the proposed system, we use the consequence- nding procedure SOL written in the Java language to perform data-driven deductive reasoning. The use of a consequence- nding procedure is convenient for updating agents' beliefs according to situation changes in the world. In our system, slave agents can change their answers frequently, yet a master agent can avoid duplicate computation. As long as actual answers from slave agents do not con- ict with any previously encountered situation, the obtained conclusions are never recomputed. We applied the proposed system to the meeting-room reservation problem to see the usefulness of the framework. 1 | [
1192,
1617
] | Train |
623 | 1 | Learning to Catch: Applying Nearest Neighbor Algorithms to Dynamic Control Tasks Steven L. Salzberg 1 and David W. Aha 2 1 Introduction Dynamic control problems are the subject of much research in machine learning (e.g., Selfridge, Sutton, & Barto, 1985; Sammut, 1990; Sutton, 1990). Some of these studies investigated the applicability of various k-nearest neighbor methods (Dasarathy, 1990) to solve these tasks by modifying control strategies based on previously gained experience (e.g., Connell & Utgoff, 1987; Atkeson, 1989; Moore, 1990; 1991). However, these previous studies did not highlight the fact that small changes in the design of these algorithms drastically alter their learning behavior. This paper describes a preliminary study that investigates this issue in the context of a difficult dynamic control task: learning to catch a ball moving in a three-dimensional space, an important problem in robotics research (Geng et al., 1991). Our thesis in this paper is that agents can improve substantially at physical tasks by storing experiences without explicitly... | [
522,
1438,
1844,
2581,
2878
] | Train |
624 | 5 | Ensembles of Classifiers Based on Approximate Reducts . A problem of improving rough set based expert systems by modifying a notion of reduct is discussed. A notion of approximate reduct is introduced, as well as some proposals of quality measure for such a reduct. A complete classifying system based on approximate reducts is presented and discussed. It is proved that a problem of nding optimal set of classifying agents based on approximate reducts is NP-hard; a genetic algorithm is used to nd the suboptimal set. Experimental results show, that the classifying system is eective and relatively fast. 1 Introduction Rough set expert systems base on the notion of reduct [11], [12], a minimal subset of attributes which is sucient to discern between objects with dierent decision values. A set of short reducts can be used to generate rules [2]. A problem of short reducts generation is NP-hard, but an approximate algorithm (like the genetic one described in [13], [8] and implemented successfully { see [10]) can be used to obtain redu... | [
2728
] | Test |
625 | 0 | Cost Effective Mobile Agent Planning for Distributed Information Retrieval The number of agents' and the execution time are two significant performance factors' in mobile agent planning. Fewer agents' cause lower network traffic and consume less bandwidth. Regardless of the number of agents' used, the execution time for a task must be kept minimal, which means that use of the minimal number of agents' must not impact on the execution time unfavorably. As the population of the mobile agent application domain grows', the importance of these two factors' also increases. | [
2553
] | Train |
626 | 2 | Learning probabilistic Datalog rules for information classification and transformation Probabilistic Datalog is a combination of classical Datalog (i.e., function-free Horn clause predicate logic) with probability theory. Therefore, probabilistic weights may be attached to both facts and rules. But it is often impossible to assign exact rule weights or even to construct the rules themselves. Instead of specifying them manually, learning algorithms can be used to learn both rules and weights. In practice, these algorithms are very slow because they need a large example set and have to test a high number of rules. We apply a number of extensions to these algorithms in order to improve efficiency. Several applications demonstrate the power of learning probabilistic Datalog rules, showing that learning rules is suitable for low dimensional problems (e.g., schema mapping) but inappropriate for higher dimensions like e.g. in text classification. | [
950
] | Train |
627 | 3 | Binary Decision Diagram Representations Of Firewall And Router Access Lists Network firewalls and routers can use a rule database to decide which packets will be allowed from one network onto another. By filtering packets the firewalls and routers can improve security and performance -- by excluding packets which may pose a security risk to a network or are not relevant to it. However, as the size of the rule list increases, it becomes difficult to maintain and validate the rules, and the cost of rule lookup may add significantly to latency. Ordered binary decision diagrams (BDDs) -- a compact method of representing and manipulating boolean expressions -- are a potential method of representing the rules. This paper explores how BDDs can be used to develop methods that help analysis of rules to validate them and changes to them, to improve performance, and facilitate hardware support. 1 Introduction The growth of network and internet communication creates several challenges for network design. Two important issues are security and performance. As the volume o... | [
1506,
2501
] | Validation |
628 | 4 | Collision Avoidance and Resolution Multiple Access for Multichannel Wireless Networks The CARMA-NTG protocol is presented and analyzed. CARMA-NTG dynamically divides the channel into cycles of variable length; each cycle consists of a contention period and a group-transmission period. During the contention period, a station with one or more packets to send competes for the right to be added to the group of stations allowed to transmit data without collisions; this is done using a collision resolution splitting algorithm based on a request-to-send/clear-to-send (RTS/CTS) message exchange with non-persistent carrier sensing. CARMA-NTG ensures that one station is added to the group transmission period if one or more stations send requests to be added in the previous contention period. The group-transmission period is a variable-length train of packets, which are transmitted by stations that have been added to the group by successfully completing an RTS/CTS message exchange in previous contention periods. As long as a station maintains its position in the group, it is able to transmit data packets without collision. An upper bound is derived for the average costs of obtaining the first success in the splitting algorithm. This bound is then applied to the computation of the average channel utilization in a fully connected network with a large number of stations. These results indicate that collision resolution is a powerful mechanism in combination with floor acquisition and group allocation multiple access. 1 | [] | Train |
629 | 2 | Data Resource Selection in Distributed Visual Information Systems With the advances in multimedia databases and the popularization of the Internet, it is now possible to access large image and video repositories distributed throughout the world. One of the challenging problems in such an access is how the information in the respective databases can be summarized to enable an intelligent selection of relevant database sites based on visual queries. This paper presents an approach to solve this problem based on image content-based indexing of a metadatabase at a query distribution server. The metadatabase records a summary of the visual content of the images in each database through image templates and statistical features characterizing the similarity distributions of the images. The selection of the databases is done by searching the metadatabase using a ranking algorithm that uses query similarity to a template and the features of the databases associated with the template. Two selection approaches, termed mean-based and histogram-based approaches, ... | [
583
] | Train |
630 | 2 | Centroid-Based Document Classification: Analysis & Experimental Results . In this paper we present a simple linear-time centroid-based document classification algorithm, that despite its simplicity and robust performance, has not been extensively studied and analyzed. Our experiments show that this centroid-based classifier consistently and substantially outperforms other algorithms such as Naive Bayesian, k-nearest-neighbors, and C4.5, on a wide range of datasets. Our analysis shows that the similarity measure used by the centroidbased scheme allows it to classify a new document based on how closely its behavior matches the behavior of the documents belonging to different classes. This matching allows it to dynamically adjust for classes with different densities and accounts for dependencies between the terms in the different classes. 1 Introduction We have seen a tremendous growth in the volume of online text documents available on the Internet, digital libraries, news sources, and company-wide intranets. It has been forecasted that these docu... | [
495,
507,
848,
1234,
1360,
1726,
1796,
2471,
2513,
2580,
2680
] | Test |
631 | 1 | Nonstandard Concepts of Similarity in Case-Based Reasoning Introduction The present paper is aimed at propagating new concepts of similarity more flexible and expressive than those underlying most case-based reasoning approaches today. So, it mainly deals with criticizing approaches in use, with motivating and introducing new notions and notations, and with first steps towards future applications. The investigations at hand originate from the author's work in learning theory. In exploring the relationship between inductive learning and case-based learning within a quite formal setting (cf. [Jan92b]), it turned out that both areas almost coincide, if sufficiently flexible similarity concepts are taken into acount. This provides some formal arguments for the necessity of non-symmetric similarity measures. Encouraged by these first results, the author tried to investigate more structured learning problems from the view point of case-based reasoning. It turned out that an appropriate handling requires formalisms allowing similarity concep | [
966,
1438,
1844,
2449
] | Train |
632 | 3 | Rule-Based Query Optimization, Revisited We present an overview and initial performance assessment of a rule-based query optimizer written in VenusDB. VenusDB is an active-database rule language embedded in C++. Following the developments in extensible database query optimizers, first in rule-based form followed by optimizers written as object-oriented programs, the VenusDB optimizer avails the advantages of both. To date, development of rule-based query optimizers have included the definition and implementation of custom rule languages. Thus, extensibility required detailed understanding and often further development of the underlying search mechanism of the rule system. Objectoriented query optimizers appear to have achieved their goals with respect to a clear organization and encapsulation of an optimizer's elements. They do not, however, provide for the concise, declarative expression of domain specific heuristics. Our experience demonstrates that a rule-based query optimizer developed in VenusDB can be well structured, ... | [
2495
] | Train |
633 | 3 | Multiversion Linear Quadtree for Spatio-Temporal Data Research in spatio-temporal databases has largely focused on extensions of access methods for the proper handling of time changing spatial information. In this paper, we present the Multiversion Linear Quadtree (MVLQ), a spatio-temporal access method based on Multiversion B-trees (MVBT) [2], embedding ideas from Linear Region Quadtrees [4]. More specifically, instead of storing independent numerical data having a different transaction-time each, for every consecutive image we store a group of codewords that share the same transaction-time, whereas each codeword represents a spatial subregion. Thus, the new structure may be used as an index mechanism for storing and accessing evolving raster images. We also conducted a thorough experimentation using sequences of real and synthetic raster images. In particular, we examined the time performance of temporal window queries, and provide results for a variety of parameter settings. | [
2939
] | Validation |
634 | 3 | Mining Source Coverage Statistics for Data Integration Recent work in data integration has shown the importance of statistical information about the coverage and overlap of sources for efficient query processing. Despite this recognition there are no effective approaches for learning the needed statistics. The key challenge in learning such statistics is keeping the number of needed statistics low enough to have the storage and learning costs manageable. Naive approaches can become infeasible very quickly. In this paper we present a set of connected techniques that estimate the coverage and overlap statistics while keeping the needed statistics tightly under control. Our approach uses a hierarchical classification of the queries, and threshold based variants of familiar data mining techniques to dynamically decide the level of resolution at which to learn the statistics. We describe the details of our method, and present preliminary experimental results showing the feasibility of the approach. 1. | [
982,
3062
] | Train |
635 | 4 | Bringing Robustness to End-User Programming In some cases, end-user programming allows the design of stand-alone applications. But none of the existing approaches is concerned by safety aspects of programming. Heavy techniques exist to develop safe applications, particularly in non-interactive domains. They involve software engineering techniques, and sometimes, formal methods. All these techniques are very far from end-users. Our idea is to let this part to experts, and to connect end-user programming onto this safe conventional development. Starting from an existing functional core, we built an interactive end-user programming environment called GenBuild, which allows designing interactive stand-alone applications. GenBuild allows the verification of some properties that are a first step towards the development of safe end-user programming. 1. | [
1645
] | Train |
636 | 1 | Learning Languages by Collecting Cases and Tuning Parameters . We investigate the problem of case-based learning of formal languages. Case-based reasoning and learning is a currently booming area of artificial intelligence. The formal framework for case-based learning of languages has recently been developed by [JL93] in an inductive inference manner. In this paper, we first show that any indexed class of recursive languages in which finiteness is decidable is case-based representable, but many classes of languages including the class of all regular languages are not case-based learnable with a fixed universal similarity measure, even if both positive and negative examples are presented. Next we consider a framework of case-based learning where the learning algorithm is allowed to learn similarity measures, too. To avoid trivial encoding tricks, we carefully examine to what extent the similarity measure is going to be learned. Then by allowing only to learn a few parameters in the similarity measures, we show that any indexed class of recursive ... | [
1490,
2062,
2281,
2330,
2882,
3160
] | Train |
637 | 5 | Building Behaviors Developmentally: A New Formalism This paper advocates a developmental approach to building complex interactive behaviors for robotic systems. A developmental methodology is advantageous because it provides a structured decomposition of complex tasks, because it facilitates learning, and because it allows for a gradual increase in task complexity. The developmental approach provides a structured means both of dividing a task among research units, as well as a metric for evaluating the progress of the task. Initial work with developmental modeling has also hinted that these skill decompositions may make the overall task easier to accomplish through the re-use of knowledge gained from developmental precursors. We report here on two projects of building behaviors developmentally for a humanoid robot. In the first project, the robot learned to reach to a visual target by following a developmental progression similar to those observed in infants. The second project outlines a proposal for building social skills developmenta... | [
1262
] | Train |
638 | 0 | Systems Directions for Pervasive Computing Pervasive computing, with its focus on users and their tasks rather than on computing devices and technology, provides an attractive vision for the future of computing. But, while hardware and networking infrastructure to realize this vision are becoming a reality, precious few applications run in this infrastructure. We believe that this lack of applications stems largely from the fact that it is currently too hard to design, build, and deploy applications in the pervasive computing space. In this paper, we argue that existing approaches to distributed computing are flawed along three axes when applied to pervasive computing; we sketch out alternatives that are better suited for this space. First, application data and functionality need to be kept separate, so that they can evolve gracefully in a global computing infrastructure. Second, applications need to be able to acquire any resource they need at any time, so that they can continuously provide their services in a highly dynamic environment. Third, pervasive computing requires a common system platform, allowing applications to be run across the range of devices and to be automatically distributed and installed. 1. | [
45,
1207
] | Train |
639 | 4 | The Challenge of Making Augmented Reality Work Outdoors this paper, along with others we have yet to imagine. Acknowledgments | [
1434,
3137
] | Train |
640 | 3 | SI-Designer: an Integration Framework for E-Commerce Electronic commerce lets people purchase goods and exchange information on business transactions on-line. Therefore one of the main challenges for the designers of the e-commerce infrastructures is the information sharing, retrieving data located in different sources thus obtaining an integrated view to overcome any contradiction or redundancy. Virtual Catalogs synthesize this approach as they are conceived as instruments to dynamically retrieve information from multiple catalogs and present product data in a unified manner, without directly storing product data from catalogs. In this paper we propose SI-Designer, a support tool for the integration of data from structured and semi-structured data sources, developed within the MOMIS (Mediator environment for Multiple Information Sources) project. 1 | [
55,
1819
] | Test |
641 | 5 | Coastal Navigation - Mobile Robot Navigation with Uncertainty in Dynamic Environments Ships often use the coasts of continents for navigation in the absence of better tools such as GPS, since being close to land allows sailors to determine with high accuracy where they are. Similarly for mobile robots, in many environments global and accurate localization is not always feasible. Environments can lack features, and dynamic obstacles such as people can confuse and block sensors. In this paper, we demonstrate a technique for generating trajectories that take into account both the information content of the environment, and the density of the people in the environment. These trajectories reduce the average positional certainty as the robot moves, reducing the likelihood the robot will become lost at any point. Our method was successfully implemented and used by the mobile robot Minerva, a museum tourguide robot, for a 2 week period in the Smithsonian National Museum of American History. 1 Introduction One essential component of any operational mobile robot system is the ab... | [
548,
556,
793
] | Train |
642 | 0 | The KRAFT Architecture for Knowledge Fusion and Transformation This paper describes the KRAFT architecture which supports the fusion of knowledge from multiple, distributed, heterogeneous sources. The architecture uses constraints as a common knowledge interchange format, expressed against a common ontology. Knowledge held in local sources can be tranformed into the common constraint language, and fused with knowledge from other sources. The fused knowledge is then used to solve some problem or deliver some information to a user. Problem-solving in KRAFT typically exploits pre-existing constraint solvers. KRAFT uses an open and flexible agent architecture in which knowledge sources, knowledge fusing entities, and users are all represented by independent KRAFT agents, communicating using a messaging protocol. Facilitator agents perform matchmaking and brokerage services between the various kinds of agent. KRAFT is being applied to an example application in the domain of network data services design. 1 Introduction and Motivation Most ... | [
525,
1552,
2584,
2990
] | Train |
643 | 3 | Nonmonotonic Inheritance in Object-Oriented Deductive Database Languages Deductive object-oriented frameworks integrate logic rules and inheritance. There, specific problems arise: Due to the combination of deduction and inheritance, (a) deduction can take place depending on inherited facts, thus raising indirect conflicts, and (b) also the class hierarchy and-membership is subject to deduction. From this point of view, we investigate the application of the extension semantics of Default Logic to deductive object-oriented database languages. By restricting the problem to Horn programs and a special type of defaults tailored to the semantics of inheritance, a forwardchaining construction of extensions is possible. This construction is compared with a solution as implemented in the F-Logic system Florid which is based on a combination of classical deductive fixpoints and an inheritance-trigger mechanism. The paper is a condensed version of [MK98]. 1 Introduction In deductive object-oriented database languages, a class hierarchy and nonmonotonic inheritance i... | [
2901
] | Test |
644 | 0 | Intention-guided Web Sites: A New Perspective on Adaptation Recent years witnessed a rapid growth of multimedia technologies for offering information and services on the internet. One of the many problems that are to be faced in this context is the great variety of possible users and the consequent need to adapt both the presentation of information and the interaction to the specific user's characteristics. | [
1501
] | Test |
645 | 5 | An Algorithm to Evaluate Quantified Boolean Formulae and its Experimental Evaluation The high computational complexity of advanced reasoning tasks such as reasoning about knowledge and planning calls for efficient and reliable algorithms for reasoning problems harder than NP. In this paper we propose Evaluate, an algorithm for evaluating Quantified Boolean Formulae, a language that extends propositional logic in a way such that many advanced forms of propositional reasoning, e.g., circumscription, can be easily formulated as evaluation of a QBF. Algorithms for evaluation of QBFs are suitable for the experimental analysis on a wide range of complexity classes, a property not easily found in other formalisms. Evaluate is based on a generalization of the Davis-Putnam procedure for SAT, and is guaranteed to work in polynomial space. Before presenting the algorithm, we discuss several abstract properties of QBFs that we singled out to make it more efficient. We also discuss various options that were investigated about heuristics and data structures, and report the main res... | [
75
] | Train |
646 | 0 | Planning and Motion Control in Lifelike Gesture: A Refined Approach In this paper an operational model for the automatic generation of lifelike gestures of an anthropomorphic virtual agent is described. The biologically motivated approach to controlling the movements of a highly articulated figure provides a transformation of spatiotemporal gesture specifications into an analog representation of the movement from which the animations are directly rendered. To this end, knowledge-based computer animation techniques are combined with appropriate methods for trajectory formation and articulated figure animation. 1. Introduction The inclusion of nonverbal modalities into the communicative behaviors of virtual agents has moved into focus of human-computer interface researchers. Humans are more likely to consider computer-generated figures lifelike when appropriate nonverbal behaviors are displayed in addition to speech. This enables the evocation of social communicative attributions to the artificial agent, which are supposed to be advantageous for a natu... | [
421,
2251
] | Train |
647 | 2 | Integrating Automatic Genre Analysis into Digital Libraries With the number and types of documents in digital library systems increasing, tools for automatically organizing and presenting the content have to be found. While many approaches focus on topic-based organization and structuring, hardly any system incorporates automatic structural analysis and representation. Yet, genre information (unconsciously) forms one of the most distinguishing features in conventional libraries and in information searches. In this paper we present an approach to automatically analyze the structure of documents and to integrate this information into an automatically created content-based organization. In the resulting visualization, documents on similar topics, yet representing dierent genres, are depicted as books in diering colors. This representation supports users intuitively in locating relevant information presented in a relevant form. Keywords Genre Analysis, Self-Organizing Map (SOM), SOMLib, Document Clustering, Visualization, Metaphor Graphics 1. | [
87,
349,
2199,
2484
] | Validation |
648 | 0 | Localisation using Automatically Selected Landmarks from Panoramic Images The use of visual landmarks for robot localisation is a promising field. It is apparent that the success of localisation by visual landmarks depends on the landmarks chosen. Good landmarks are those which remain reliable over time and through changes in position and orientation. This paper describes a system which learns places by automatically selecting landmarks from panoramic images and uses them for localisation tasks. An adaption of the biologically inspired Turn Back and Look behaviour is used to evaluate potential landmarks. Normalised correlation is used to overcome the a#ects of changes in illumination in the environment. Results from real robot experiments are reported, showing successful localisation from up to one meter away from the learnt position. 1 Introduction Visual localisation is one of the key problems in making successful autonomous robots. Vision as a sensor is the richest source of information about a mobile agent's environment and as such con... | [
1428
] | Test |
649 | 5 | Adaptation Techniques for Intrusion Detection and Intrusion Response Systems This paper examines techniques for providing adaptation in intrusion detection and intrusion response systems. As attacks on computer systems are becoming increasingly numerous and sophisticated, there is a growing need for intrusion detection and response systems to dynamically adapt to better detect and respond to attacks. The Adaptive Hierarchical Agentbased Intrusion Detection System (AHA! IDS) provides detection adaptation by adjusting the amount of system resources devoted to the task of detecting intrusive activities. This is accomplished by dynamically invoking new combinations of lower level detection agents in response to changing circumstances and by adjusting the confidence associated with these lower-level agents. The Adaptive Agentbased Intrusion Response System (AAIRS) provides response adaptation by weighting those responses that have been successful in the past over those techniques that have not been as successful. As a result, the more successful responses are used... | [
1240,
1335,
2833
] | Train |
650 | 2 | Measuring the Structural Similarity among XML Documents and DTDs Sources of XML documents are proliferating on the Web and documents are more and more frequently exchanged among sources. At the same time, there is an increasing need of exploiting database tools to manage this kind of data. An important novelty of XML is that information on document structures is available on the Web together with the document contents. This information can be used to improve document handling and to achieve more effective and efficient searches on documents. However, in such an heterogeneous environment as the Web, it is not reasonable to assume that XML documents that enter a source always conform to a predefined DTD present in the source. | [
2273
] | Test |
651 | 3 | Scheduling Queries on Tape-resident Data Advances in storage technology have made near-line tertiary storage a viable alternative for database and data warehouse systems. Tertiary storage systems are employed in cases where secondary storage can not satisfy the data handling requirements or tertiary storage is more cost effective option. Tertiary storage devices have traditionally been used as archival storage. The new application domains require on-demand retrieval of data from these devices. This paper investigates issues in optimizing I/O time for a query whose data resides on automated tertiary storage containing multiple storage devices. We model the problem as a limited storage parallel two-machine flow-shop scheduling problem with additional constraints. Given a query, we establish an upper bound on the number of storage devices for an optimal I/O schedule and provide experimental proof for it. For queries that access small amounts of data from multiple media, we derive an optimal schedule analytically. For q... | [
2399
] | Test |
652 | 1 | Evolutionary Approaches to Off-Line Routing in Backbone Communications Networks Off-line routing in backbone communications networks is an important combinatorial optimisation problem. It has three main uses: first, off-line routing provides reference benchmark results for dynamic (on-line) routing strategies. Second, and more interestingly, off-line routing is becoming more and more investigated and employed in its own right as a way of quickly finding significantly improved routings for live networks which can then be imposed on the network to offer a net improvement in quality of service. Third, it can be used in networks where bandwidth may be booked in advance. In this paper we introduce and investigate a number of heuristic techniques applicable to the routing problem for use in stochastic, iterative search. Results are presented which indicate that these heuristics significantly improve the search for solutions, particularly when on-line performance is considered. We also investigate how computation time can be further reduced by the use of delta-evaluation... | [
1359,
2061
] | Train |
653 | 3 | Optimizing Object Queries Using an Effective Calculus Object-oriented databases (OODBs) provide powerful data abstractions and modeling facilities but they generally lack a suitable framework for query processing and optimization. One of the key factors for OODB systems to successfully compete with relational systems as well as to meet the performance requirements of many non-traditional applications is the development of an effective query optimizer. We propose an effective framework with a solid theoretical basis for optimizing OODB query languages. Our calculus, called the monoid comprehension calculus, captures most features of ODMG OQL and is a good basis for expressing various optimization algorithms concisely. This paper concentrates on query unnesting, an optimization that, even though improves performance considerably, is not treated properly (if at all) by most OODB systems. Our framework generalizes many unnesting techniques proposed recently in the literature and is capable of removing any form of query nesting using a very si... | [
869,
1101,
2575
] | Train |
654 | 0 | A Unified View of Plans as Recipes Plans as recipes or abstract structures, as well as plans as mental attitudes that guide an agent in its planning process has been enthusiastically embraced by both philosophers and AI practitioners. They play a central role in a class of rational agents, called Belief-Desire-Intention (BDI) agents. This dual view of plans can not only be used for efficient planning, but can also be used for recognizing the plans of other agents, coordinating one's actions and achieving joint intentions with other members of a larger collective or team, and finally recognizing the collective plans and intentions of other teams. In this paper, we start with a simple notion of execution plans and discuss its operational semantics. We progressively extend this notion of plans to recognition plans, joint execution plans, and joint recognition plans. The primary contribution of this paper is in providing an integrated view of plans that facilitate individual an collective planning and recognition. 1 Int... | [
485,
1951,
2016
] | Train |
655 | 3 | Making LDAP Active with the LTAP Gateway: Case Study in Providing Telecom Integration and Enhanced Services LDAP (Lightweight Directory Access Protocol) directories are being rapidly deployed on the Web. They are currently used to store data like white pages information, user profiles, and network device descriptions. These directories offer a number of advantages over current database technology in that they provide better support for heterogeneity and scalability. However, they lack some basic database functionality (e.g., triggers, transactions) that is crucial for Directory Enabled Networking (DEN) tasks like provisioning network services, allocating resources, reporting, managing end-to-end security, and offering mobile users customized features that follow them. In order to address these limitations while keeping the simplicity and performance features of LDAP directories, unbundled and portable solutions are needed. In this paper we discuss LDAP limitations we faced while building an LDAP meta-directory that integrates data from legacy telecom systems, and how LTAP (Lightweight Trigger Access Process), a portable gateway that adds active functionality to LDAP directories, overcomes these limitations. | [
1672,
1787,
3024
] | Test |
656 | 3 | Textural Features for Image Database Retrieval This paper presents two feature extraction methods and two decision methods to retrieve images having some section in them that is like the user input image. The features used are variances of gray level co-occurrences and line-angle-ratio statistics constituted by a 2-D histogram of angles between two intersecting lines and ratio of mean gray levels inside and outside the regions spanned by those angles. The decision method involves associating with any pair of images either the class “relevant” or “irrelevant”. A Gaussian classifier and nearest neighbor classifier are used. A protocol that translates a frame throughout every image to automatically define for any pair of images whether they are in the relevance class or the irrelevance class is discussed. Experiments on a database of 300 gray scale images with 9,600 groundtruth image pairs showed that the classifier assigned 80 % of the image pairs we were sure were relevant, to the relevance class correctly. The actual retrieval accuracy is greater than this lower bound of 80%. | [
2019
] | Train |
657 | 5 | Learning Similarity Space In this study, we suggest a method to adapt an image retrieval system into a configurable one. Basically, original feature space of a content-based retrieval system is nonlinearly transformed into a new space, where the distance between the feature vectors is adjusted by learning. The transformation is realized by Artificial Neural Network architecture. A cost function is defined for learning and optimized by simulated annealing method. Experiments are done on the texture image retrieval system, which use Gabor Filter features. The results indicate that configured image retrieval system is significantly better than the original system. 1. | [
103,
224,
1119,
1973
] | Train |
658 | 3 | STHoles: A Multidimensional Workload-Aware Histogram Attributes of a relation are not typically independent. Multidimensional histograms can be an effective tool for accurate multiattribute query selectivity estimation. In this paper, we introduce STHoles,a\workload-aware" histogram that allows bucket nesting to capture data regions with reasonably uniform tuple density. STHoles histograms are built without examining the data sets, but rather by just analyzing query results. Buckets are allocated where needed the most as indicated by the workload, which leads to accurate query selectivity estimations. Our extensive experiments demonstrate that STHoles histograms consistently produce good selectivity estimates across synthetic and real-world data sets and across query workloads, and, in many cases, outperform the best multidimensional histogram techniques that require access to and processing of the full data sets during histogram construction. 1. | [] | Train |
659 | 4 | A New TWIST on Mobile Computing: Two-Way Interactive Session Transfer The ubiquitous use of computer resources for daily productivity is a goal that presently remains unrealised. We believe that the convergence of desktop and mobile applications into a seamless computing experience will provide a strong motivation for future "anytime, anywhere computing." In this paper we describe this convergence as the capability to perform the handoff of application sessions across heterogeneous platforms using the network as a conduit. In addition to discussing the architecture and protocols to facilitate this capability, in this paper we also provide a taxonomy for describing a variety of different session handoff schemes. In particular, we have identified an important Two-Way Interactive Session Transfer (TWIST) behaviour for communication between heterogeneous clients and servers. To demonstrate our concepts, we have implemented the handoff capability with TWIST semantics into a real-world application that serves as a teaching tool for radiology clinicians. From experimental data we will show that the handoff mechanism incurs little delay to transfer large dataladen sessions. 1 | [
348,
1496,
2447
] | Validation |
660 | 4 | Beyond Fitts' Law: Models for Trajectory-Based HCI Tasks Trajectory-based interactions, such as navigating through nested-menus, drawing curves, and moving in 3D worlds, are becoming common tasks in modern computer interfaces. Users' performances in these tasks cannot be successfully modeled with Fitts' law as it has been applied to pointing tasks. Therefore we explore the possible existence of robust regularities in trajectory-based tasks. We used "steering through tunnels" as our experimental paradigm to represent such tasks, and found that a simple "steering law" indeed exists. The paper presents the motivation, analysis, a series of four experiments, and the applications of the steering law. | [
1802
] | Validation |
661 | 3 | Indexing Semistructured Data This paper describes techniques for building and exploiting indexes on semistructured data: data that may not have a fixed schema and that may be irregular or incomplete. We first present a general framework for indexing values in the presence of automatic type coercion. Then based on Lore, a DBMS for semistructured data, we introduce four types of indexes and illustrate how they are used during query processing. Our techniques and indexing structures are fully implemented and integrated into the Lore prototype. 1 Introduction We call data that is irregular or that exhibits type and structural heterogeneity semistructured, since it may not conform to a rigid, predefined schema. Such data arises frequently on the Web, or when integrating information from heterogeneous sources. In general, semistructured data can be neither stored nor queried in relational or object-oriented database management systems easily and efficiently. We are developing Lore 1 , a database management system d... | [
392,
781,
1086,
1453,
3027
] | Validation |
662 | 5 | Discovering Interesting Association Rules in Medical Data We are presently exploring the idea of discovering association rules in medical data. There are several technical aspects which make this problem challenging. In our case medical data sets are small, but have high dimensionality. Information content is rich: there exist numerical, categorical, time and even image attributes. Data records are generally noisy. We explain how to map medical data to a transaction format suitable for mining rules. The combinatorial nature of association rules matches our needs, but current algorithms are unsuitable for our purpose. We thereby introduce an improved algorithm to discover association rules in medical data which incorporates several important constraints. Some interesting results obtained by our program are discussed and we explain how the program parameters were set. We believe many of the problems we come across are likely to appear in other domains. 1 Introduction Data Mining is an active research area. One of the most popular approaches t... | [
192,
1648
] | Train |
663 | 2 | MARIAN: Flexible Interoperability for Federated Digital Libraries Federated digital libraries are composed of distributed autonomous (heterogeneous) information services but provide users with a transparent, integrated view of collected information – respecting different information sources’ autonomy. In this paper we discuss a federated system for the Networked Digital Library of Theses and Dissertations (NDLTD), an international consortium of universities, libraries, and other supporting institutions focused on electronic theses and dissertations (ETDs). The NDLTD has so far allowed its members considerable autonomy, though agreements are developing on metadata standards and on support of the Open Archives initiative that eventually will promote greater homogeneity. At present, federation requires dealing flexibly with differences among systems, ontologies, and data formats. Our solution involves adapting MARIAN, an objectoriented digital library retrieval system developed with support by NLM and NSF, to serve as mediation middleware for the federated NDLTD collection. Components of the solution include: 1) the use of several harvesting techniques; 2) an architecture based on object-oriented ontologies of search modules and metadata; 3) diversity within the harvested data joined to a single collection view for the user; and 4) an integrated framework for addressing such questions as data quality, information compression, and flexible search. The system can handle very large dynamic collections. An adaptable relationship between the collection view and harvested data facilitates adding new sites to the federation and adapting to changes in existing sites. MARIAN’s modular architecture and powerful and flexible data model work together to build an effective integrated solution within a simple uniform framework. We present both the general design of the system and operational details of a preliminary federated collection involving several thousand ETDs in four different formats and two languages from USA and Europe. | [
1677
] | Train |
664 | 4 | Visual Contextual Awareness in Wearable Computing Small, body-mounted video cameras enable a different style of wearable computing interface. As processing power increases, a wearable computer can spend more time observing its user to provide serendipitous information, manage interruptions and tasks, and predict future needs without being directly commanded by the user. This paper introduces an assistant for playing the real-space game Patrol. This assistant tracks the wearer's location and current task through computer vision techniques and without off-body infrastructure. In addition, this paper continues augmented reality research, started in 1995, for binding virtual data to physical locations. 1. Introduction For most computer systems, even virtual reality systems, sensing techniques are a means of getting input directly from the user. However, wearable computers offer a unique opportunity to re-direct sensing technology towards recovering more general user context. Wearable computers have the potential to "see" as the user sees... | [
681,
727,
1110,
1186,
1556,
1598,
1731,
1757,
2225,
2472,
2656,
2763
] | Validation |
665 | 0 | Task Models, Intentions, and Agent Conversation Policies . It is possible to define conversation policies, such as communication or dialogue protocols, that are based strictly on what messages and, respectively, what performatives may follow each other. While such an approach has many practical applications, such protocols support only "local coherence" in a conversation. Lengthy message exchanges require some infrastructure to lend them "global coherence." Recognition of agent intentions about the joint task is essential for this global coherence, but there are further mechanisms needed to ensure that both local and global coherence are jointly maintained. This paper presents a general yet practical approach to designing, managing, and engineering agents that can do simple run-time intention recognition without creating complex multi-state protocols. In this approach we promote developing abstract task models and designing conversation policies in terms of such models. An implemented agent assistant based on these ideas is brie... | [
2364
] | Train |
666 | 0 | Knowledge Modeling - State of the Art A major characteristic of developments in the broad field of Artificial Intelligence (AI) during the 1990s has been an increasing integration of AI with other disciplines. A number of other computer science fields and technologies have been used in developing intelligent systems, starting from traditional information systems and databases, to modern distributed systems and the Internet. This paper surveys knowledge modeling techniques that have received most attention in recent years among developers of intelligent systems, AI practitioners and researchers. The techniques are described from two perspectives, theoretical and practical. Hence the first part of the paper presents major theoretical and architectural concepts, design approaches, and research issues. The second part discusses several practical systems, applications, and ongoing projects that use and implement the techniques described in the first part. Finally, the paper briefly covers some of the most recent results in the fields of intelligent manufacturing systems, intelligent tutoring systems, and ontologies. 2 1. | [
275,
924,
2629
] | Train |
667 | 4 | Coverage Problems in Wireless Ad-hoc Sensor Networks Wireless ad-hoc sensor networks have recently emerged as a premier research topic. They have great long term economic potential, ability to transform our lives, and pose many new system building challenges. Sensor networks also pose a number of new conceptual and optimization problems. Some, such as location, deployment, and tracking, are fundamental issues, in that many applications rely on them for needed information. In this paper, we address one of the fundamental problems, namely coverage. Coverage in general, answers the questions about quality of service (surveillance) that can be provided by a particular sensor network. We first define the coverage problem from several points of view including deterministic, statistical, worst and best case, and present examples in each domain. By combining computational geometry and graph theoretic techniques, specifically the Voronoi diagram and graph search algorithms, we establish the main highlight of the paper - optimal polynomial time worst and average case algorithm for coverage calculation. We also present comprehensive experimental results and discuss future research directions related to coverage in sensor networks. I. | [
3080
] | Test |
668 | 3 | Run-time Detection in Parallel and Distributed Systems: An Application to Safety-Critical Applications As systems are becoming more complex, there is increasing interest in their runtime analysis, understanding their dynamic behavior and possibly controling it as well. This paper describes complex distributed and parallel applications that use run-time analyses to attain scalability improvements with respect to the amount and complexity of the data transmitted, transformed, and shared among different application components. Such improvements are derived from using database techniques when manipulating data streams. Namely, by imposing a relational model on a data stream, filters and constraints on the stream may be expressed in the form of database queries evaluated against the data events comprising the stream. Streams may then be filtered using runtime optimization techniques derived from query optimization methods. This paper also presents a tool, termed Cnet, which offers (1) means for the dynamic creation of queries and their application to distributed data streams, (2) permits the... | [
30
] | Train |
669 | 3 | Specialising The Other Way Around In this paper, we present a program transformation based on bottom up evaluation of logic programs. We explain that using this technique, programs can be "specialised" w.r.t. a set of unit clauses instead of a query. Moreover, examples indicate that excellent specialisation can be obtained when this bottom up transformation is combined with a more traditional top down approach, resulting in conceptually cleaner techniques requiring a less complicated control than one overall approach. 1 | [
3135
] | Train |
670 | 1 | Learning and Decision-Making in the Framework of Fuzzy Lattices A novel theoretical framework is delineated for supervised and unsupervised learning. It is called framework of fuzzy lattices, or FLframework for short, and it suggests mathematically sound tools for dealing separately and/or jointly with disparate types of data including vectors of numbers, fuzzy sets, symbols, etc. Specific schemes are proposed for clustering and classification having the capacity to deal with both missing and don't care data values; the schemes in question can be implemented as neural networks. The proposed learning schemes are employed here for pattern recognition on seven data sets including benchmark data sets, and the results are compared with those ones by various learning techniques from the literature. Finally, aiming at a mutual cross-fertilization, the FL-framework is associated with established theories for learning and/or decision-making including probability theory, fuzzy set theory, Bayesian decision-making, theory of evidence, and adaptive resonance t... | [
1389,
1980
] | Train |
671 | 5 | A Description Logic for Vague Knowledge This work introduces the concept language ALCFM which is an extension of ALC to many-valued logics. ALCFM allows to express vague concepts, e.g. more or less enlarged or very small. To realize this extension to many-valued logics, the classical notions of satisfiability and subsumption had to be modified appropriately. For example, ALCFM -concepts are no longer either satisfiable or unsatisfiable, but they are satisfiable to a certain degree. The main contribution of this paper is a sound and complete method for computing the degree of subsumption between two ALCFM -concepts. 1 Introduction This work takes its motivation from the occurrence of vague concept descriptions in different application areas. Often, application--inherent information is characterized by a very high degree of vagueness. Appropriate information systems must be able to process this kind of data. So far, there are no systems that really solve the corresponding problems due to the lack of powerful basic methods. A... | [
377
] | Validation |
672 | 0 | Towards Robust Teams with Many Agents Agents in deployed multi-agent systems monitor other agents to coordinate and collaborate robustly. However, as the number of agents monitored is scaled up, two key challenges arise: (i) the number of monitoring hypotheses to be considered can grow exponentially in the number of agents; and (ii) agents become physically and logically unconnected (unobservable) to their peers. This paper examines these challenges in teams of cooperating agents, focusing on a monitoring task that is of particular importance to robust teamwork: detecting disagreements among team-members. We present YOYO, a highly scalable disagreement-detection algorithm which guarantees sound detection in time linear in the number of agents despite the exponential number of hypotheses. In addition, we present new upper bounds about the number of agents that must be monitored in a team to guarantee disagreement detection. Both YOYO and the new bounds are explored analytically and empirically in thousands of monitoring problems, scaled to thousands of agents. | [
109,
424,
1717,
1724,
2359
] | Train |
673 | 1 | Intelligent Telecommunication Technologies anage telecommunication networks. Building such applications involved acquiring valuable telecommunication knowledge from human experts and then applying this knowledge, typically by embedding it in an expert system. This knowledge acquisition process is so time-consuming that it is referred to as the "knowledge acquisition bottleneck". Data mining techniques are now being applied to industrial applications to break this bottleneck, by replacing the manual knowledge acquisition process with automated knowledge discovery. Telecommunication networks, which routinely generate tremendous amounts of data, are ideal candidates for data mining [1]. This section will describe expert system and data mining technologies and how they are evolving to solve complex industrial problems. 1.1 Expert Systems Expert systems are programs which represent and apply factual knowledge of specific areas of expertise to solve problems [2]. Expert systems have been applied extensively within | [
1030
] | Validation |
674 | 0 | Interactive Pedagogical Drama This paper describes an agent-based approach to realizing interactive pedagogical drama. Characters choose their actions autonomously, while director and cinematographer agents manage the action and its presentation in order to maintain story structure, achieve pedagogical goals, and present the dynamic story to as to achieve the best dramatic effect. Artistic standards must be maintained while permitting substantial variability in story scenario. To achieve these objectives, scripted dialog is deconstructed into elements that are portrayed by agents with emotion models. Learners influence how the drama unfolds by controlling the intentions of one or more characters, who then behave in accordance with those intentions. Interactions between characters create opportunities to move the story in pedagogically useful directions, which the automated director exploits. This approach is realized in the multimedia title Carmen's Bright IDEAS, an interactive health intervention designed to impro... | [
2470,
2815,
2992
] | Validation |
675 | 4 | Classification Space for Augmented Surgery, an Augmented Reality Case Study One of the recent design goals in Human Computer Interaction has been to extend the sensorymotor capabilities of computer systems to combine the real and the virtual in order to assist the user in his environment. Such systems are called Augmented Reality (AR). Although AR systems are becoming more prevalent we still do not have a clear understanding of this interaction paradigm. In this paper we propose OPAS as a generic framework for classifying existing AR systems. Computer Assisted Medical Interventions (CAMI), for which the added value of AR has been demonstrated by experience, are discussed in light of OPAS. We illustrate OPAS using our system, CASPER (Computer ASsisted PERicardial puncture), a CAMI system which assists in surgical procedures (pericardial punctures). KEYWORDS: Augmented Surgery, CAMI, Augmented Reality, Classification Space 1. INTRODUCTION The term "Augmented Reality" (AR) appears in the literature usually in conjunction with the term "Virtual Reality" (VR). Th... | [
599
] | Train |
676 | 2 | Amalthaea: Information Discovery and Filtering using a Multiagent Evolving Ecosystem Agents are semi-intelligent programs that assist the user in performing repetitive and time-consuming tasks. Information discovery and information filtering are a suitable domain for applying agent technology. Ideas drawn from the field of autonomous agents and artificial life are combined in the creation of an evolving ecosystem composed of competing and cooperating agents. A co-evolution model of information filtering agents that adapt to the various user's interests and information discovery agents that monitor and adapt to the various on-line information sources is analyzed. Results from a number of experiments are presented and discussed. Keywords: Agents, Information Filtering, Evolution, World-Wide-Web 1 Introduction The exponential increase of computer systems that are interconnected in on-line networks has resulted in a corresponding exponential increase in the amount of information available on-line. This information is distributed among heterogeneous sources and is... | [
1094,
1269,
1377,
2336,
2689,
3025,
3170
] | Train |
677 | 3 | Leveraging Mediator Cost Models with Heterogeneous Data Sources : Distributed systems require declarative access to diverse data sources of information. One approach to solving this heterogeneous distributed database problem is based on mediator architectures. In these architectures, mediators accept queries from users, process them with respect to wrappers, and return answers. Wrapper provide access to underlying data sources. To efficiently process queries, the mediator must optimize the plan used for processing the query. In classical databases, cost-estimate based query optimization is an effective method for optimization. In a heterogeneous distributed databases, cost-estimate based query optimization is difficult to achieve because the underlying data sources do not export cost information. This paper describes a new method that permits the wrapper programmer to export cost estimates (cost estimate formulas and statistics). For the wrapper programmer to describe all cost estimates may be impossible due to lack of information or burdensome due... | [
1181
] | Train |
678 | 3 | The Logic Programming Paradigm | [] | Train |
679 | 3 | The Information Integration Wizard (IWiz) Project data. To illustrate the need for integration of heterogeneous data sources, suppose we have a scenario where consumers want to purchase computer-related products from one of the many e-commerce sites. However, before making the purchase they would like to gather all the relevant, available information in order to help them in their decision making process. For example, consumers may want to access product information on available desktops, laptops, software, and other accessories and check availability and pricing information. In addition, users may also want to access other online sources for related background information such as consumer reports, press releases etc. This situation is depicted in Figure 1. Typically, each source uses different tools and data modeling techniques to create and manage their data. This means, the same concept, for example, the entity software, may be described by a different term and different set of attributes in different sources (e.g | [
965
] | Train |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.