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1,080 | 1 | Extraction and Classification of Visual Motion Patterns for Hand Gesture Recognition We present a new method for extracting and classifying motion patterns to recognize hand gestures. First, motion segmentation of the image sequence is generated based on a multiscale transform and attributed graph matching of regions across frames. This produces region correspondences and their affine transformations. Second, color information of motion regions is used to determine skin regions. Third, human head and palm regions are identified based on the shape and size of skin areas in motion. Finally, affine transformations defining a region's motion between successive frames are concatenated to construct the region's motion trajectory. Gestural motion trajectories are then classified by a time-delay neural network trained with backpropagation learning algorithm. Our experimental results show that hand gestures can be recognized well using motion patterns. 1 Introduction This paper is concerned with the problem of detecting two-dimensional motion across image frames and classifyi... | [
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1,081 | 3 | Temporal Objects for Spatio-Temporal Data Models and a Comparison of Their Representations Abstract: Currently, there are strong efforts to integrate spatial and temporal database technology into spatio-temporal database systems. This paper views the topic from a rather fundamental perspective and makes several contributions. First, it reviews existing temporal and spatial data models and presents a completely new approach to temporal data modeling based on the very general notion of temporal object. The definition of temporal objects is centered around the observation that anything that changes over time can be expressed as a function over time. For the modeling of spatial objects the well known concept of spatial data types is employed. As specific subclasses, linear temporal and spatial objects are identified. Second, the paper proposes the database embedding of temporal objects by means of the abstract data type (ADT) approach to the integration of complex objects into databases. Furthermore, we make statements about the expressiveness of different temporal and spatial database embeddings. Third, we consider the combination of temporal and spatial objects into spatio-temporal objects in (relational) databases. We explain various alternatives for spatio-temporal data models and databases and compare their expressiveness. Spatio-temporal objects turn out to be specific instances of temporal objects. 1 | [
341,
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1,082 | 4 | Using Digital but Physical Surrogates to Mediate Awareness, Communication and Privacy in Media Spaces Digital but physical surrogates are tangible representations of remote people, typically members of small intimate teams, positioned within an office and under digital control. Surrogates selectively collect and present awareness information about the people they represent. They also react to people's explicit and implicit physical actions: a person's explicit acts include grasping and moving them, while implicit acts include one's proximity to the surrogate. By responding appropriately to these physical actions of people, surrogates can control the communication capabilities of a media space in a natural way. This enables the smooth transition from awareness to casual interaction while mitigating concerns about privacy. Keywords: Ubiquitous media spaces, awareness, casual interaction, groupware, CSCW. 1. INTRODUCTION Digital but physical surrogates are tangible representations of remote people, typically members of small intimate teams, positioned within a person's environment. As ... | [
1671,
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1,083 | 4 | Vision-Based User Interface for Interacting with a Virtual Environment Abstract. This paper proposes a new and natural human computer interface for interacting with virtual environments. The 3D pointing direction of a user in a virtual environment is estimated using monocular computer vision. The 2D position of the user’s hand is extracted in the image plane and then mapped to a 3D direction using knowledge about the position of the user’s head and kinematic constraints of a pointing gesture due to the human motor system. Off-line tests of the system show promising results. The implementation of a real time system is currently in progress and is expected to run with 25Hz. 1 | [
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1,084 | 4 | WebAdapter: A prototype of a WWW-browser with new special needs adaptations . This paper presents a prototypical WWW (World Wide Web)-browser called "WebAdapter", which provides new special needs adaptations for physically handicapped, blind and visually impaired end-users. These adaptations include near miss tolerances, implementation of sophisticated HTMLguidelines and advanced speech output. For evaluation purposes a usability test was conducted proving the suitability of the implemented special needs adaptations. The future goal of this work is a user interface for all (UI4All) for a standard Webbrowser. With regard to this perspective, the WebAdapter is still an reactive approach in that it only reacts to shortcomings of common Webbrowsers instead of proactively integrating a standardized software layer between the user front-end and underlying applications by which the I/O-Interface can easily and universally be adapted to a variety of different personal needs of handicapped as well as able-bodied end-users. Thus, the WebAdapter only illustrates... | [
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1,085 | 2 | Text Mining with Information Extraction The popularity of the Web and the large number of documents available in electronic form has motivated the search for hidden knowledge in text collections. Consequently, there is growing research interest in the general topic of text mining. In this paper, we develop a text-mining system by integrating methods from Information Extraction (IE) and Data Mining (Knowledge Discovery from Databases or KDD). By utilizing existing IE and KDD techniques, text-mining systems can be developed relatively rapidly and evaluated on existing text corpora for testing IE systems. We present a general text-mining framework called DiscoTEX which employs an IE module for transforming natural-language documents into structured data and a KDD module for discovering prediction rules from the extracted data. When discovering patterns in extracted text, strict matching of strings is inadequate because textual database entries generally exhibit variations due to typographical errors, misspellings, abbreviations, and other | [
605,
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1,086 | 3 | On Supporting Containment Queries in Relational Database Management Systems Virtually all proposals for querying XML include a class of query we term “containment queries”. It is also clear that in the foreseeable future, a substantial amount of XML data will be stored in relational database systems. This raises the question of how to support these containment queries. The inverted list technology that underlies much of Information Retrieval is well-suited to these queries, but should we implement this technology (a) in a separate loosely-coupled IR engine, or (b) using the native tables and query execution machinery of the RDBMS? With option (b), more than twenty years of work on RDBMS query optimization, query execution, scalability, and concurrency control and recovery immediately extend to the queries and structures that implement these new operations. But all this will be irrelevant if the performance of option (b) lags that of (a) by too much. In this paper, we explore some performance implications of both options using native implementations in two commercial relational database systems and in a special purpose inverted list engine. Our performance study shows that while RDBMSs are generally poorly suited for such queries, under certain conditions they can outperform an inverted list engine. Our analysis further identifies two significant causes that differentiate the performance of the IR and RDBMS implementations: the join algorithms employed and the hardware cache utilization. Our results suggest that contrary to most expectations, with some modifications, a native implementation in an RDBMS can support this class of query much more efficiently. | [
661,
930,
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1,087 | 2 | Subspace Information Criterion for Non-Quadratic Regularizers - Model Selection for Sparse Regressors Non-quadratic regularizers, in particular the # 1 norm regularizer can yield sparse solutions that generalize well. In this work we propose the Generalized Subspace Information Criterion (GSIC) that allows to predict the generalization error for this useful family of regularizers. We show that under some technical assumptions GSIC is an asymptotically unbiased estimator of the generalization error. GSIC is demonstrated to have a good performance in experiments with the # 1 norm regularizer as we compare with the Network Information Criterion and cross-validation in relatively large sample cases. However in the small sample case, GSIC tends to fail to capture the optimal model due to its large variance. Therefore, also a biased version of GSIC is introduced, which achieves reliable model selection in the relevant and challenging scenario of high dimensional data and few samples. Subspace Information Criterion for Non-Quadratic Regularizers 2 1 | [
103
] | Train |
1,088 | 4 | ARQuake: An Outdoor/Indoor Augmented Reality First Person Application This pap er presents an outdoor/indoor augmented re- ality first person applic ationAR(2uake we have developal. ARQuake is an extension of the desktop game Quake, and as such we are investigating how to convert a desktop first person application into an outdoor/indoor mobile augmented reality application. We present an archire cture for a low cost, moderately accurate six degrees of freedom tracking system based on GP$, digital compass, and fiducial vision-based tracking. Usability issues such as monster selection, colour, and input devies are discussed. A second application for AR architectural design visualisation is presented. | [
469,
1713,
2363,
2425
] | Test |
1,089 | 3 | An Evaluation of Real-Time Transaction Management Issues in Mobile Database Systems A critical issue in mobile data management is to respond to real-time data access requirements of the supported application. However, it is difficult to handle real-time constraints in a mobile computing environment due to the physical constraints imposed by the mobile computer hardware and the wireless network technology. In this paper, we present a mobile database system model that takes into account the timing requirements of applications supported by mobile computing systems. We provide a transaction execution model with two alternative execution strategies for mobile transactions and evaluate the performance of the system considering various mobile system characteristics, such as the number of mobile hosts in the system, the handoff process, disconnection, coordinator site relocation, and wireless link failure. Performance results are provided in terms of the fraction of real-time requirements that are satisfied. 1 Introduction A mobile computing system is a dynamic type of trad... | [
954,
2543
] | Validation |
1,090 | 2 | A Shopping Agent That Automatically Constructs Wrappers for Semi-Structured Online Vendors . This paper proposes a shopping agent with a robust inductive learning method that automatically constructs wrappers for semistructured online stores. Strong biases assumed in many existing systems are weakened so that the real stores with reasonably complex document structures can be handled. Our method treats a logical line as a basic unit, and recognizes the position and the structure of product descriptions by finding the most frequent pattern from the sequence of logical line information in output HTML pages. This method is capable of analyzing product descriptions that comprise multiple logical lines, and even those with extra or missing attributes. Experimental tests on over 60 sites show that it successfully constructs correct wrappers for most real stores. 1 Introduction A shopping agent is a mediator system that extracts the product descriptions from several online stores on a user's behalf. Since the stores are heterogeneous, a procedure for extracting the cont... | [
801,
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] | Train |
1,091 | 2 | Exploiting Geographical Location Information of Web Pages Many information resources on the web are relevant primarily to limited geographical communities. For instance, web sites containing information on restaurants, theaters, and apartment rentals are relevant primarily to web users in geographical proximity to these locations. In contrast, other information resources are relevant to a broader geographical community. For instance, an on-line newspaper may be relevant to users across the United States. Unfortunately, the geographical scope of web resources is largely ignored by web search engines. We make the case for identifying and exploiting the geographical location information of web sites so that web search engines can rank resources in a geographically sensitive fashion, in addition to using more traditional information-retrieval strategies. In this paper, we first consider how to compute the geographical location of web pages. Subsequently, we consider how to exploit such information in one specific "proof-of-concept" appl... | [
2459,
2503,
2716
] | Train |
1,092 | 4 | MRML: Towards an extensible standard for multimedia querying and benchmarking In recent years, the need for databases which query multimedia data by content has become apparent. Many commercial and non--commercial research groups are trying to fulfill these needs. The development of research can be described as moving in two directions ffl search for new, useful query and interaction paradigms ffl deeper research to improve the performance of systems that have adopted a given query paradigm. The search for new better performance given a query paradigm has led to "clusters" of systems which are similar in their interaction with the user, and which give a certain set of interaction capabilities to the user. It is already visible, that research will move towards systems which enable the user to formulate multi--paradigm queries in order to further improve results. As a consequence of the above, there is the need for ffl A common mechanism for shipping multi--paradigm queries and their results , which assures that the right query processor processes th... | [
1972
] | Train |
1,093 | 5 | Position Estimation for Mobile Robots in Dynamic Environments For mobile robots to be successful, they have to navigate safely in populated and dynamic environments. While recent research has led to a variety of localization methods that can track robots well in static environments, we still lack methods that can robustly localize mobile robots in dynamic environments, in which people block the robot’s sensors for extensive periods of time or the position of furniture may change. This paper proposes extensions to Markov localization algorithms enabling them to localize mobile robots even in densely populated environments. Two different filters for determining the “believability ” of sensor readings are employed. These filters are designed to detect sensor readings that are corrupted by humans or unexpected changes in the environment. The technique was recently implemented and applied as part of an installation, in which a mobile robot gave interactive tours to visitors of the “Deutsches Museum Bonn. ” Extensive empirical tests involving datasets recorded during peak traffic hours in the museum demonstrate that this approach is able to accurately estimate the robot’s position in more than 98 % of the cases even in such highly dynamic environments. | [
213,
793,
1881,
2190,
3021
] | Validation |
1,094 | 2 | Alerting Services in a Digital Library Environment The classical paradigm of finding information in the WWW by initiating retrieval and browsing becomes more and more ineffective. Other techniques have to be considered. Automatic delivery of contents to the user according to their needs and filtered by her profile of interests is required. Current implementations of such Alerting Services at content providers side have several drawbacks. In my research project I evaluate methods and techniques for Alerting Services with special respect to the area of digital libraries. I intend to provide a framework that supports design decisions in building alerting services depending on the infrastructure and desired system parameters. 1 Introduction Imagine one morning you just arrive at your office and switch on your computer to have a look at the recent news in your special field of research. Little pictures for each topic tell you that some interesting documents arrived. Behind one icon you find for instance the new announcements for c... | [
676
] | Validation |
1,095 | 2 | Incorporating Quality Metrics in Centralized/Distributed Information Retrieval on the World Wide Web Most information retrieval systems on the Internet rely primarily on similarity ranking algorithms based solely on term frequency statistics. Information quality is usually ignored. This leads to the problem that documents are retrieved without regard to their quality. We present an approach that combines similarity-based similarity ranking with quality ranking in centralized and distributed search environments. Six quality metrics, including the currency, availability, information-to-noise ratio, authority, popularity, and cohesiveness, were investigated. Search effectiveness was significantly improved when the currency, availability, information-to-noise ratio and page cohesiveness metrics were incorporated in centralized search. The improvement seen when the availability, information-to-noise ratio, popularity, and cohesiveness metrics were incorporated in site selection was also significant. Finally, incorporating the popularity metric in information fusion resulted in a significan... | [
1690
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1,096 | 3 | Filtering Algorithms and Implementation for Very Fast Publish/Subscribe Systems Publish/Subscribe is the paradigm in which users express long-term interests (\subscriptions") and some agent \publishes " events (e.g., oers). The job of Publish/Subscribe software is to send events to the owners of subscriptions satis ed by those events. For example, a user subscription may consist of an interest in an airplane of a certain type, not to exceed a certain price. A published event may consist of an oer of an airplane with certain properties including price. Each subscription consists of a conjunction of (attribute, comparison operator, value) predicates. A subscription closely resembles a trigger in that it is a longlived conditional query associated with an action (usually, informing the subscriber). However, it is less general than a trigger so novel data structures and implementations may enable the creation of more scalable, high performance publish /subscribe systems. This paper describes an attempt at the construction of such algorithms and its implementation. Using a combination of data structures, application-speci c caching policies, and application-speci c query processing our system can handle 600 events per second for a typical workload containing 6 million subscriptions. | [
230,
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] | Train |
1,097 | 4 | What Shall We Teach Our Pants? If a wearable device can register what the wearer is currently doing, it can anticipate and adjust its behavior to avoid redundant interaction with the user. However, the relevance and properties of the activities that should be recognized depend on both the application and the user. This requires an adaptive recognition of the activities where the user, instead of the designer, can teach the device what he/she is doing. As a case study we connected a pair of pants with accelerometers to a laptop to interpret the raw sensor data. Using a combination of machine learning techniques such as Kohonen maps and probabilistic models, we build a system that is able to learn activities while requiring minimal user attention. This approach to context awareness is more universal since it requires no a priori knowledge about the contexts or the user. 1. | [
1227,
2225,
2472,
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] | Train |
1,098 | 5 | Approximating Discrete Probability Distributions With Bayesian Networks I generalise the arguments of [Chow & Liu 1968] to show that a Bayesian network satisfying some arbitrary constraint that best approximates a probability distribution is one for which mutual information weight is maximised. I give a practical procedure for nding an approximation network and evaluate its application on a range of data sets. Articial intelligence requires the ability to reach conclusions that may be far from certain. For example an expert system for medical diagnosis may be given the symptoms of some patient and asked to provide a diagnosis | even though the background knowledge and symptom information may not be enough to determine for sure which problem actually besets the patient. Probability theory provides a plausible model for reasoning under uncertainty, since one would expect a diagnosis to be relatively probable, given the symptoms. This paper addresses practical issues to do with the implementation of probabilistic reasoning. The plan is rst to discuss... | [
941,
2905
] | Train |
1,099 | 3 | Data Warehouse Scenarios for Model Management Model management is a framework for supporting meta-data related applications where models and mappings are manipulated as first class objects using operations such as Match, Merge, ApplyFunction, and Compose. To demonstrate the approach, we show how to use model management in two scenarios related to loading data warehouses. The case study illustrates the value of model management as a methodology for approaching meta-data related problems. It also helps clarify the required semantics of key operations. These detailed scenarios provide evidence that generic model management is useful and, very likely, implementable. | [
444,
2237,
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] | Train |
1,100 | 3 | A Database Approach for Modeling and Querying Video Data Indexing video data is essential for providing content based access. In this paper, we consider how database technology can offer an integrated framework for modeling and querying video data. As many concerns in video (e.g., modeling and querying) are also found in databases, databases provide an interesting angle to attack many of the problems. From a video applications perspective, database systems provide a nice basis for future video systems. More generally, database research will provide solutions to many video issues even if these are partial or fragmented. From a database perspective, video applications provide beautiful challenges. Next generation database systems will need to provide support for multimedia data (e.g., image, video, audio). These data types require new techniques for their management (i.e., storing, modeling, querying, etc.). Hence new solutions are significant. This paper develops a data model and a rule-based query language for video content based indexing a... | [
3181
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1,101 | 3 | Optimizing Queries with Object Updates Object-oriented databases (OODBs) provide powerful data abstractions and modeling facilities but they usually lack a suitable framework for query processing and optimization. Even though there is an increasing number of recent proposals on OODB query optimization, only few of them are actually focused on query optimization in the presence of object identity and destructive updates, features often supported by most realistic OODB languages. This paper presents a formal framework for optimizing object-oriented queries in the presence of side effects. These queries may contain object updates at any place and in any form. We present a language extension to the monoid comprehension calculus to express these object-oriented features and we give a formal meaning to these extensions. Our method is based on denotational semantics, which is often used to give a formal meaning to imperative programming languages. The semantics of our language extensions is expressed in terms of our monoid calculu... | [
653,
869,
2575
] | Train |
1,102 | 3 | Adding Compression to Block Addressing Inverted Indexes . Inverted index compression, block addressing and sequential search on compressed text are three techniques that have been separately developed for efficient, low-overhead text retrieval. Modern text compression techniques can reduce the text to less than 30% of its size and allow searching it directly and faster than the uncompressed text. Inverted index compression obtains significant reduction of their original size at the same processing speed. Block addressing makes the inverted lists point to text blocks instead of exact positions and pay the reduction in space with some sequential text scanning. In this work we combine the three ideas in a single scheme. We present a compressed inverted file that indexes compressed text and uses block addressing. We consider different techniques to compress the index and study their performance with respect to the block size. We compare the index against three separate techniques for varying block sizes, showing that our index is superior to each isolated approach. For instance, with just 4% of extra space overhead the index has to scan less than 12% of the text for exact searches and about 20% allowing one error in the matches. Keywords: Text compression, inverted files, block addressing, text databases. 1. | [
2700
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1,103 | 3 | Using WG-Log to represent semistructured data: the example of OEM . In this paper we discuss the possibility to represent synthetically semistructured information via a loose notion of schema: we say that data are semistructured when, although some structure is present, it is not as strict, regular, or complete as the one required by the traditional database management systems. Our proposal is based on WG-Log, a graph based language for the representation of WWW site information. We show how information encoded in a typical semistructured information model, as OEM, can be represented and queried by means of the WG-Log language, and how the TSIMMIS and WG-Log Web Query System can be integrated to allow site content exploration and exploitation by means of WG-Log. 1 Introduction We say that data are semistructured when, although some structure is present, it is not as strict, regular, or complete as the one required by the traditional database management systems (see [Abi97] for a survey on semistructured data). Information is semistructured also when... | [
2872
] | Train |
1,104 | 0 | Agent Interoperation Across Multagent System Boundaries Recently the number of autonomous agents and multiagent systems (MAS) that have been developed by different developers has increased. Despite efforts for the creation of standards (eg. in communication languages, registration protocols etc.), it is clear that at least in the near term heterogeneous agents and MASs will be prevalent. Therefore, mechanisms that allow agents and/or MASs to interoperate and transact are needed. In this paper we report on a case study and lessons learned of an interoperator agent we developed. We discuss requirements for interoperation mechanisms, resulting challenges and our design decisions and implementation of the RETSINA-OAA InterOperator | [
2249
] | Validation |
1,105 | 2 | Using Text Elements by Context to Display Search Results in Information Retrieval Systems - Model and Research Results Information retrieval systems display search results by various methods. This paper focuses on a model for displaying a list of search results by means of textual elements that utilize a new information unit that replaces the currently used information unit. The paper includes a short description of several studies that support the model. 1. Introduction Because of the growth in the number and scope of global databases, a special approach is required to locating information, from the perspective of the user interface. The Internet, as it exists today, is an outstanding example of a broad-base, unfocused database. Most Internet search engines display their information as a serially ordered list of results (with a partial attempt at ranking the results). In most cases, this list includes the document title, URL and, at times, the first few lines of the document. The information, as currently displayed to the user, is incomplete and insufficiently focused on the search query. This requi... | [
1627,
2535,
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1,106 | 1 | Estimating Mixture Models of Images and Inferring Spatial Transformations Using the EM Algorithm Presented at the IEEE Conference on Computer Vision and Pattern Recognition, Ft. Collins, CO, June, 1999. Mixture modeling and clustering algorithms are effective, simple ways to represent images using a set of data centers. However, in situations where the images include background clutter and transformations such as translation, rotation, shearing and warping, these methods extract data centers that include clutter and represent dierent transformations of essentially the same data. Taking face images as an example, it would be more useful for the dierent clusters to represent dierent poses and expressions, instead of cluttered versions of dierent translations, scales and rotations. By including clutter and transformation as unobserved, latent variables in a mixture model, we obtain a new \transformed mixture of Gaussians", which is invariant to a specied set of transformations. We show how a linear-time EM algorithm can be used to t this model by jointly estimating a mixture mo... | [
1890
] | Train |
1,107 | 0 | Environment Centered Analysis and Design of Coordination Mechanisms Environment Centered Analysis and Design of Coordination Mechanisms May 1995 KEITH S. DECKER B.S., Carnegie Mellon University M.S., Rensselaer Polytechnic Institute Ph.D., University of Massachusetts Amherst Directed by: Professor Victor R. Lesser Committee: Professor Paul R. Cohen Professor John A. Stankovic Professor Douglas L. Anderton Coordination, as the act of managing interdependencies between activities, is one of the central research issues in Distributed Artificial Intelligence. Many researchers have shown that there is no single best organization or coordination mechanism for all environments. Problems in coordinating the activities of distributed intelligent agents appear in many domains: the control of distributed sensor networks; multi-agent scheduling of people and/or machines; distributed diagnosis of errors in local-area or telephone networks; concurrent engineering; `software agents' for information gathering. The design of coordination mechanisms for groups of compu... | [
14,
438,
779,
792,
852,
978,
996,
1139,
1210,
1378,
2043,
2202,
2398,
2635,
2753,
2877
] | Validation |
1,108 | 2 | Context in Web Search Web search engines generally treat search requests in isolation. The results for a given query are identical, independent of the user, or the context in which the user made the request. Nextgeneration search engines will make increasing use of context information, either by using explicit or implicit context information from users, or by implementing additional functionality within restricted contexts. Greater use of context in web search may help increase competition and diversity on the web. | [
159,
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1432,
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2068,
2275,
2418,
2459,
2464,
2503,
2569,
2716,
2849,
3037,
3077,
3099
] | Test |
1,109 | 3 | A Data Preparation Framework based on a Multidatabase Language Integration and analysis of data from different sources have to deal with several problems resulting from potential heterogeneities. The activities addressing these problems are called data preparation and are supported by various available tools. However, these tools process mostly in a batch-like manner not supporting the iterative and explorative nature of the integration and analysis process. In this work we present a framework for important data preparation tasks based on a multidatabase language. This language offers features for solving common integration and cleaning problems as part of query processing. Combining data preparation mechanisms and multidatabase query facilities permits applying and evaluating different integration and cleaning strategies without explicit loading and materialization of data. The paper introduces the language concepts and discusses their application for individual tasks of data preparation. | [
1582,
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1,110 | 4 | Symbiotic Interfaces For Wearable Face Recognition We introduce a wearable face detection method that exploits constraints in face scale and orientation imposed by the proximity of participants in near social interactions. Using this method we describe a wearable system that perceives “social engagement,” i.e., when the wearer begins to interact with other individuals. One possible application is improving the interfaces of portable consumer electronics, such as cellular phones, to avoid interrupting the user during face-to-face interactions. Our experimental system proved> 90 % accurate when tested on wearable video data captured at a professional conference. Over three hundred individuals were captured, and the data was separated into independent training and test sets. A goal is to incorporate user interface in mobile machine recognition systems to improve performance. The user may provide real-time feedback to the system or may subtly cue the system through typical daily activities, such as turning to face a speaker, as to when conditions for recognition are favorable. 1 | [
664,
727,
1556,
1757,
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] | Train |
1,111 | 1 | Learning Intonation Rules for Concept-to-Speech Generation We aim to design and develop a Concept-to-Speech (CTS) generation system, a speech synthesis system producing speech from semantic representations, by integrating language generation with speech synthesis. We focus on five issues (1) how to employ newly available accurate discourse, semantic, and syntactic information produced by a natural language generation system to improve the quality of synthesized speech. (2) how to extend an existing general purpose natural language generation system to a Concept-to-Speech generation tool. (3) how to integrate rule induction into a CTS architecture to separate the domain-dependent prosodic rules from the prosody generation component. (4) how to design a speech interface language to facilitate a more flexible and open CTS architecture. (5) how to build prosody models and explore their use in multimedia synchronization. Unlike previous CTS research, we utilize linguistic constraints provided by a general purpose natural language generation system;... | [
314,
1587,
2931
] | Validation |
1,112 | 3 | First-Order Queries On Finite Structures Over The Reals We investigate properties of finite relational structures over the reals expressed by first-order sentences whose predicates are the relations of the structure plus arbitrary polynomial inequalities, and whose quantifiers can range over the whole set of reals. In constraint programming terminology, this corresponds to Boolean real polynomial constraint queries on finite structures. The fact that quantifiers range over all reals seems crucial; however, we observe that each sentence in the first-order theory of the reals can be evaluated by letting each quantifier range over only a finite set of real numbers without changing its truth value. Inspired by this observation, we then show that when all polynomials used are linear, each query can be expressed uniformly on all finite structures by a sentence of which the quantifiers range only over the finite domain of the structure. In other words, linear constraint programming on finite structures can be reduced to ordinary query evaluation as usual in finite model theory and databases. Moreover, if only "generic" queries are taken into consideration, we show that this can be reduced even further by proving that such Dept. Math. & Computer Sci., University of Antwerp (UIA), Universiteitsplein 1, B-2610 Antwerp, Belgium. E-mail: pareda@uia.ac.be. y Dept. WNI, University of Limburg (LUC), B-3590 Diepenbeek, Belgium. E-mail: vdbuss@luc.ac.be. z Computer Science Department, Indiana University, Bloomington, IN 47405-4101, USA. E-mail: vgucht@cs.indiana.edu. 1 queries can be expressed by sentences using as polynomial inequalities only those of the simple form x ! y. 1 | [] | Validation |
1,113 | 0 | An Architecture for Mobile BDI Agents BDI (Belief, Desire, Intention) is a mature and commonly adopted architecture for Intelligent Agents. BDI Agents are autonomous entities able to work in teams and react to changing environmental conditions. However, the current computational model adopted by BDI has problems which, amongst other limitations, prevent the development of mobile agents. In this paper, we discuss an architecture, TOMAS (Transaction Oriented Multi Agent System), that addresses these issues by combining BDI and the distributed nested transaction paradigms. An algorithm is presented which enable agents in TOMAS to become mobile. 1 Introduction Intelligent Agents are a very active area of AI research [WJ95] [Sho93]. Of the various agent architectures which have been proposed, BDI (Belief, Desire, Intention) [RG92] is probably the most mature and has been adopted by a few industrial applications. BDI Agents are autonomous entities able to work in teams and react to changing environmental conditions. Mobile m... | [
1605,
1922,
1951,
2153,
2706
] | Train |
1,114 | 2 | PlanetP: Infrastructure Support for P2P Information Sharing Storage technology trends' are providing massive storage in extremely small packages while declining computing costs' are resulting in a rising number of devices' per person. The confluence of these trends' are presenting a new, critical challenge to storage and file system designers': how to enable users' to effectively manage, use, and share huge amounts' of data stored across a multitude of devices. In this paper, we present a novel middleware storage system, PlanetP, which is designed from first principles as' a peerto -peer (P2P), semantically indexed storage layer. PlanetP makes two novel design choices to meet the above challenge. First, PlanetP concentrates on content-based querying for information retrieval and assumes that the unit of storage is a shipper of XML, allowing it to index arbitrary data for search and retrieval regardless of the applications' used to create and manipulate the data. Second, PlanetP adopts' a P2P approach, avoiding centralization of storage and indexing. This' makes PlanetP particularly suitable for information sharing among ad hoc groups of users, each of which may have to manage data distributed across multiple devices'. PlanetP is' targeted for groups of up to 1000 users'; results' from studying communities of lO0-200 peers' running on a cluster of PCs indicates that PlanetP should scale well to the 1000-member threshold. Finally, we describe BreezeFS, a semantic file system that we have implemented to validate PlanetP's utility. | [
1505,
2503
] | Train |
1,115 | 5 | Learning Quantitative Knowledge for Multiagent Coordination A central challenge of multiagent coordination is reasoning about how the actions of one agent affect the actions of another. Knowledge of these interrelationships can help coordinate agents --- preventing conflicts and exploiting beneficial relationships among actions. We explore three interlocking methods that learn quantitative knowledge of such non-local effects in TAEMS, a well-developed framework for multiagent coordination. The surprising simplicity and effectiveness of these methods demonstrates how agents can learn domain-specific knowledge quickly, extending the utility of coordination frameworks that explicitly represent coordination knowledge. Introduction A major challenge of designing effective multiagent systems is managing non-local effects --- situations where the actions of one agent impact the performance of other agents' actions. For example, one agent's action can enable, disable, facilitate, or hinder the actions of other agents. Poor accounting for ... | [
978,
996,
2358,
2753
] | Train |
1,116 | 3 | Design and Implementation of the ROL System ROL is a deductive object-oriented database system developed at the University of Regina. It eectively integrates important features of deductive databases and object-oriented databases in a uniform framework and provides a uniform rule-based declarative language for dening, manipulating and querying a database. This paper describes the latest implementation of ROL. 1 Introduction In the past decade a lot of interests arose in integrating deductive and object-oriented databases to gain the best of the two approaches such as recursion, declarative querying, and rm logical foundations from deductive approaches, and object identity, complex objects, classes, class hierarchy, property inheritance with overriding and schema from object-oriented approach. A number of deductive object-oriented database languages have been proposed, such as O-logic [17], revised O-logic [11], C-logic [8], IQL [2], IQL2[1], Flogic [10], LOGRES [7], LLO [16], LOL [6], CORAL++[19], Datalog method [3], DLT ... | [
418,
2083
] | Train |
1,117 | 2 | Gleaning Answers From the Web Introduction This position paper summarizes my recent and ongoing research on Web information extraction and retrieval. I describe wrapper induction and verification techniques for extracting data from structured sources; boosted wrapper induction, an extension of these techniques to handle natural text; ELIXIR, our e#cient and expressive language for XML information retrieval ; techniques and applications for text genre classification; and stochastic models for XML schema alignment. The unifying theme of these various research projects is to develop enabling technologies that facilitate the rapid development of large Web services for data access and integration. 2 Wrapper induction and verification A wide variety of valuable textual information resides on the Web, but very little is in a machineunderstandable form such as XML. Instead, the content | [
413,
2199
] | Test |
1,118 | 0 | Simplifying the Development of Intelligent Agents Intelligent agents is a powerful Artificial Intelligence technology which shows considerable promise as a new paradigm for mainstream software development. However, despite their promise, intelligent agents are still scarce in the market place. A key reason for this is that developing intelligent agent software requires significant training and skill: a typical developer or undergraduate struggles to develop good agent systems using the Belief Desire Intention (BDI) model (or similar models). This paper identifies the concept set which we have found to be important in developing intelligent agent systems and the relationships between these concepts. This concept set was developed with the intention of being clearer, simpler, and easier to use than current approaches. We also describe briefly a (very simplified) example from one of the projects we have worked on (RoboRescue), illustrating the way in which these concepts are important in designing and developing intelligent software agents. Keywords: AI Architectures, distributed AI, multiagent systems, reactive control, software agents. 1 | [
1049,
3168
] | Validation |
1,119 | 2 | Distance-From-Boundary As A Metric For Texture Image Retrieval A new metric is proposed for texture image retrieval, which is based on the signed distance of the images in the database to a boundary chosen by the query. This novel metric has three advantages: 1) the boundary distance measures are relatively insensitive to the sample distributions; 2) same retrieval results can be obtained with respect to different (but visually similar) queries; 3) retrieval performance can be improved. The boundaries are obtained by using a statistical learning algorithm called support vector machine (SVM), and hence the boundaries can be simply represented by some vectors and their combination coefficients. Experimental results on the Brodatz texture database indicate that a significantly better retrieval performance can be achieved as compared to the traditional Euclidean distance based approach. This technique can be further developed to learn pattern similarities among different texture classes and used in relevance feedback. | [
657,
1973,
2675
] | Train |
1,120 | 2 | STARTS: Stanford Proposal for Internet Meta-Searching Document sources are available everywhere, both within the internal networks of organizations and on the Internet. Even individual organizations use search engines from different vendors to index their internal document collections. These search engines are typically incompatible in that they support different query models and interfaces, they do not return enough information with the query results for adequate merging of the results, and finally, in that they do not export metadata about the collections that they index (e.g., to assist in resource discovery). This paper describes STARTS, an emerging protocol for Internet retrieval and search that facilitates the task of querying multiple document sources. STARTS has been developed in a unique way. It is not a standard, but a group effort coordinated by Stanford's Digital Library project, and involving over 11 companies and organizations. The objective of this paper is not only to give an overview of the STARTS protocol proposal, but... | [
521,
583,
587,
879,
1038,
1108,
1167,
1455,
1767,
1804,
1888,
2712,
2771
] | Train |
1,121 | 3 | An Efficient Index Structure for OID Indexing in Parallel Temporal Object-Oriented Database Systems . In an object-oriented database system based on logical OIDs, an OID index (OIDX) is necessary to convert from logical OID to physical location. In a temporal objectoriented database system (TOODB), this OIDX also contains the timestamps of the object versions. We have in a previous paper studied OIDX performance with a relatively simple index. The studies have shown that OIDX maintenance can be quite costly, especially objects updates, because in a temporal OODB, the OIDX needs to be updated every time an object is updated. This has convinced us that a new index structure, particularly suitable to TOODB requirements, is necessary. In this report, we describe an efficient OID index structure for TOODBs, which we call The Vagabond Temporal OID Index (VTOIDX). The main goals of the VTOIDX is 1) support for temporal data, while still having index performance close to a non-temporal/one version database system, 2) efficient object-relational operation, and 3) easy tertiary storage migrati... | [
1441,
1803
] | Train |
1,122 | 1 | General Cost Functions for Support Vector Regression The concept of Support Vector Regression is extended to a more general class of convex cost functions. Moreover it is shown how the resulting convex constrained optimization problems can be efficiently solved by a Primal--Dual Interior Point path following method. Both computational feasibility and improvement of estimation is demonstrated in the experiments. 1. Introduction 1.1. Risk Minimization In the following we will consider the problem of regression estimation: For some probability density function p(x; y) on R n\Omega R and some cost function C(¸) find a function f that minimizes the following risk functional. R[f ] = Z C(y \Gamma f(x))p(x; y)dxdy (1) However we do not know p(x; y). Instead we only have observations f(x 1 ; y 1 ); : : : (x ` ; y ` )g; x i 2 R n ; y i 2 R at hand that have been drawn iid (independent identially distributed) from p(x; y). Hence the first guess would be to replace p by the empirical density derived from our observations and minimize the... | [
842,
1400,
2177
] | Train |
1,123 | 1 | A Voxel Based Representation for Evolutionary Shape Optimisation AND KEYWORDS PAGE Title: A Voxel Based Representation for Evolutionary Shape Optimisation Abstract A voxel-based shape representation when integrated with an evolutionary algorithm offers a number of potential advantage for shape optimisation. Topology need not be predefined, geometric constraints are easily imposed and, with adequate resolution, any shape can be approximated to arbitrary accuracy. However, lack of boundary smoothness, length of chromosome and inclusion of small holes in the final shape have been stated as problems with this representation. This paper describes two experiments performed in an attempt to address some of these problems. Firstly, a design problem with only a small computational cost of evaluating candidate shapes was used as a testbed for designing genetic operators for this shape representation. Secondly, these operators were refined for a design problem using a more costly finite element evaluation. It was concluded that the voxel representation can, with careful design of genetic operators, be useful in shape optimisation. Keywords: shape optimisation, evolutionary algorithms, voxel representation. 1. | [
1005
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1,124 | 1 | Simultaneous Learning of Negatively Correlated Neural Networks A new approach to designing neural network ensembles has been proposed recently [1]. Experimental studies on some regression tasks have shown that the new approach performs significantly better than previous ones [1]. This paper presents a new algorithm for designing neural network ensembles for classification problems with noise. This new algorithm is different from that used for regression tasks although the idea is similar. The idea behind this new algorithm is to encourage different individual networks in an ensemble to learn different parts or aspects of the training data so that the whole ensemble can learn the whole training data better. Negatively correlated networks are trained with a novel correlation penalty term in the error function to encourage such specialisation. In our algorithm, individual networks are trained simultaneously rather than sequentially. This provides an opportunity for different networks to interact with other and to specialise. Experiments on two real-w... | [
244
] | Train |
1,125 | 2 | Global Integration of Visual Databases Different visual databases have been designed in various locations. The global integration of such databases can enable users to access data across the world in a transparent manner. In this paper, we investigate an approach to the design and creation of an integrated information system which supports global visual query access to various visual databases over the Internet. Specifically, a metaserver including a hierarchical metadatabase, a metasearch agent, and a query manager is designed to support such an integration. The metadatabase houses abstracted data about individual remote visual databases. To support visual contentbased queries, the abstracted data in the metadatabase reflect the semantics of each visual database. The query manager extracts the feature contents from the queries. The metasearch agent processes the queries by matching their feature contents with the metadata. A list of relevant database sites is derived for efficient retrieval of the query in the selected dat... | [
1167
] | Test |
1,126 | 1 | Unsupervised Learning from Dyadic Data Dyadic data refers to a domain with two finite sets of objects in which observations are made for dyads, i.e., pairs with one element from either set. This includes event co-occurrences, histogram data, and single stimulus preference data as special cases. Dyadic data arises naturally in many applications ranging from computational linguistics and information retrieval to preference analysis and computer vision. In this paper, we present a systematic, domain-independent framework for unsupervised learning from dyadic data by statistical mixture models. Our approach covers different models with flat and hierarchical latent class structures and unifies probabilistic modeling and structure discovery. Mixture models provide both, a parsimonious yet flexible parameterization of probability distributions with good generalization performance on sparse data, as well as structural information about data-inherent grouping structure. We propose an annealed version of the standard Expectation Maximization algorithm for model fitting which is empirically evaluated on a variety of data sets from different domains. | [
110,
149,
988,
1345,
1718,
2800,
2847
] | Train |
1,127 | 3 | Fast Approximate Evaluation of OLAP Queries for Integrated Statistical Data We have developed a mediator architecture that integrates statistical information about energy products from several government agencies, such as the Bureau of Labor Statistics, the Energy Information Administration, and the California Energy Commission. Our architecture has a dual mode of operation. First, our system can retrieve live data from databases and web sources from these agencies. This allows the users to obtain completely up-to-date data. However, for complex analytical queries that typically require large amounts of data and processing, live access does not offer the level of interactivity that some users require. Second, our system can warehouse the information from the data sources to allow for complex analytical queries to be executed much more efficiently. However, the data would be only as recent as the last update to the data warehouse. In this paper we describe the architecture and focus on how to perform analytical queries against the data warehouse very efficiently. We present results using a fast wavelet-based technique for progressive evaluation of range-sum queries. This technique allows for returning an approximate result to the query very efficiently and for fast convergence to the exact result. We envision users exploring many complex queries using the very fast approximate results as guidance and only obtaining the exact results for those queries that are deemed of interest. We present experimental results showing the efficiency of both approximate and exact queries. 1 | [
857,
2205
] | Test |
1,128 | 2 | Towards Efficient Multi-Feature Queries in Heterogeneous Environments Applications like multimedia databases or enterprisewide information management systems have to meet the challenge of efficiently retrieving best matching objects from vast collections of data. We present a new algorithm Stream-Combine for processing multi-feature queries on heterogeneous data sources. Stream-Combine is selfadapting to different data distributions and to the specific kind of the combining function. Furthermore we present a new retrieval strategy that will essentially speed up the output of relevant objects. | [
1249,
1257,
2864,
2865
] | Train |
1,129 | 0 | Spatial Agents Implemented in a Logical Expressible Language In this paper, we present a multi-layered architecture for spatial and temporal agents. The focus is laid on the declarativity of the approach, which makes agent scripts expressive and well understandable. They can be realized as (constraint) logic programs. The logical description language is able to express actions or plans for one and more autonomous and cooperating agents for the RoboCup (Simulator League). The system architecture hosts constraint technology for qualitative spatial reasoning, but quantitative data is taken into account, too. The basic (hardware) layer processes the agent's sensor information. An interface transfers this lowlevel data into a logical representation. It provides facilities to access the preprocessed data and supplies several basic skills. The second layer performs (qualitative) spatial reasoning. On top of this, the third layer enables more complex skills such as passing, offside-detection etc. At last, the fourth layer establishes acting as a team both by emergent and explicit cooperation. Logic and deduction provide a clean means to specify and also to implement teamwork behavior. 1 | [
403,
780,
2182
] | Train |
1,130 | 1 | Hierarchical Multi-Agent Reinforcement Learning In this paper we investigate the use of hierarchical reinforcement learning to speed up the acquisition of cooperative multi-agent tasks. We extend the MAXQ framework to the multi-agent case. Each agent uses the same MAXQ hierarchy to decompose a task into sub-tasks. Learning is decentralized, with each agent learning three interrelated skills: how to perform subtasks, which order to do them in, and how to coordinate with other agents. Coordination skills among agents are learned by using joint actions at the highest level(s) of the hierarchy. The Q nodes at the highest level(s) of the hierarchy are configured to represent the joint task-action space among multiple agents. In this approach, each agent only knows what other agents are doing at the level of sub-tasks, and is unaware of lower level (primitive) actions. This hierarchical approach allows agents to learn coordination faster by sharing information at the level of sub-tasks, rather than attempting to learn coordination taking into account primitive joint state-action values. We apply this hierarchical multi-agent reinforcement learning algorithm to a complex AGV scheduling task and compare its performance and speed with other learning approaches, including at multi-agent, single agent using MAXQ, selfish multiple agents using MAXQ (where each agent acts independently without communicating with the other agents), as well as several well-known AGV heuristics like "first come first serve", "highest queue first" and "nearest station first". We also compare the tradeoffs in learning speed vs. performance of modeling joint action values at multiple levels in the MAXQ hierarchy. | [
1221,
1964,
3147
] | Test |
1,131 | 3 | Generalized Isolation Level Definitions Commercial databases support different isolation levels to allow programmers to trade off consistency for a potential gain in performance. The isolation levels are defined in the current ANSI standard, but the definitions are ambiguous and revised definitions proposed to correct the problem are too constrained since they allow only pessimistic (locking) implementations. This paper presents new specifications for the ANSI levels. Our specifications are portable; they apply not only to locking implementations, but also to optimistic and multi-version concurrency control schemes. Furthermore, unlike earlier definitions, our new specifications handle predicates in a correct and flexible manner at all levels. 1. Introduction This paper gives new, precise definitions of the ANSISQL isolation levels [6]. Unlike previous proposals [13, 6, 8], the new definitions are both correct (they rule out all bad histories) and implementation-independent. Our specifications allow a wide range of concurr... | [
768
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1,132 | 1 | Learning human arm movements by imitation: Evaluation of a biologically-inspired connectionist architecture . This paper is concerned with the evaluation of a model of human imitation of arm movements. The model consists of a hierarchy of artificial neural networks, which are abstractions of brain regions involved in visuo-motor control. These are the spinal cord, the primary and pre-motor cortexes (M1 & PM), the cerebellum, and the temporal cortex. A biomechanical simulation is developed which models the muscles and the complete dynamics of a 37 degree of freedom humanoid. Input to the model are data from human arm movements recorded using video and marker-based tracking systems. The model's performance is evaluated for reproducing reaching movements and oscillatory movements of the two arms. Results show a high qualitative and quantitative agreement with human data. In particular, the model reproduces the well known features of reaching movements in humans, namely the bell-shaped curves for the velocity and quasi-linear hand trajectories. Finally, the model's performance is compar... | [
926,
2636,
2863
] | Test |
1,133 | 1 | Differential Join Prices for Parallel Queues: Social Optimality, Dynamic Pricing Algorithms and Application to Internet Pricing We consider a system of identical parallel queues served by a single server and distinguished only by the price charged at entry. A Poisson stream of customers joins the queue by a greedy policy that minimizes a `disutility' that combines price and congestion. A special case of linear disutility is analyzed for which it is shown that the individually optimal greedy queue join policy is nearly socially optimal. For this queueing system, a Markov decision theoretic framework is formulated for dynamic pricing in the general case. This queueing system has application in the pricing of Internet services. | [
22
] | Test |
1,134 | 2 | Detection of Heterogeneities in a Multiple Text Database Environment As the number of text retrieval systems (search engines) grows rapidly on the World Wide Web, there is an increasing need to build search brokers (metasearch engines) on top of them. Often, the task of building an effective and efficient metasearch engine is hindered by the heterogeneities among the underlying local search engines. In this paper, we first analyze the impact of various heterogeneities on building a metasearch engine. We then present some techniques that can be used to detect the most prominent heterogeneities among multiple search engines. Applications of utilizing the detected heterogeneities in building better metasearch engines will be provided. | [
263,
521,
587,
976,
1167,
1308,
1642,
1804,
1888,
2275,
2464,
2503,
2556,
3139
] | Train |
1,135 | 2 | Speaker Tracking in Broadcast Audio Material in the Framework of the THISL Project In this paper, we present a first approach to build an automatic system for broadcast news speaker-based segmentation. Based on a Chop-and-Recluster method, this system is developed in the framework of the THISL project. A metric-based segmentation is used for the Chop procedure and different distances have been investigated. The Recluster procedure relies on a bottom-up clustering of segments obtained beforehand and represented by non-parametricmodels. Various hierarchical clustering schemes have been tested. Some experiments on BBC broadcast news recordings show that the system can detect real speaker changes with high accuracy (mean error ' 0.7s) and fair false alarm rate (mean false alarm rate ' 5.5% ). The Recluster procedure can produce homogeneous clusters but it is not already robust enough to tackle too complex classification tasks. 1. INTRODUCTION THISL (THematic Indexing of Spoken Language) 1 is an ESPRIT Long Term Research project that is investigating the development ... | [
1070
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1,136 | 2 | Probabilistic Question Answering on the Web Web-based search engines such as Google and NorthernLight return documents that are relevant to a user query, not answers to user questions. We have developed an architecture that augments existing search engines so that they support natural language question answering. The process entails five steps: query modulation, document retrieval, passage extraction, phrase extraction, and answer ranking. In this paper we describe some probabilistic approaches to the last three of these stages. We show how our techniques apply to a number of existing search en-1 Radev et al. 2 gines and we also present results contrasting three different methods for question answering. Our algorithm, probabilistic phrase reranking (PPR), uses proximity and question type features and achieves a total reciprocal document rank of.20 on the TREC8 corpus. Our techniques have been implemented as a Web-accessible system, called NSIR. | [
582,
1352,
1529
] | Train |
1,137 | 5 | Recognition of Human Action Using Moment-Based Features The performance of different classification approaches is evaluated using a view-based approach for motion representation. The view-based approach uses computer vision and image processing techniques to register and process the video sequence [6, 23]. Two motion representations called Motion Energy Images and Motion History Images [6] are then constructed. These representations collapse the temporal component in a way that no explicit temporal analysis or sequence matching is needed. Statistical descriptions are then computed using momentbased features and dimensionality reduction techniques. For these tests, we used 7 Hu moments, which are invariant to scale and translation. Principal Components Analysis is used to reduce the dimensionality of this representation. The system is trained using different subjects performing a set of examples of every action to be recognized. Given these samples, K-nearest neighbor, Gaussian, and Gaussian mixture classifiers are used to recognize new acti... | [
2015,
2933
] | Train |
1,138 | 1 | Using Case-Based Reasoning for Supporting Continuous Improvement Processes The goal of the IPQM project -- a collaboration of the Fraunhofer Institute for Manufacturing Engineering and Automation (IPA) in Stuttgart and the Fraunhofer Institute for Experimental Software Engineering (IESE) in Kaiserslautern -- is to develop a technical infrastructure to support continuous improvement processes. We describe the approach we took in some detail and focus on the implementation of the IPQM system and its currently ongoing evaluation in the healthcare sector. We also give an outlook on intended extensions of the system and its application in other domains. | [
1813
] | Train |
1,139 | 0 | Achieving Coordination through Combining Joint Planning and Joint Learning . There are two major approaches to activity coordination in multiagent systems. First, by endowing the agents with the capability to jointly plan, that is, to jointly generate hypothetical activity sequences. Second, by endowing the agents with the capability to jointly learn, that is, to jointly choose the actions to be executed on the basis of what they know from experience about the interdependencies of their actions. This paper describes a new algorithm called JPJL ("Joint Planning and Joint Learning") that combines both approaches. The primary motivation behind this algorithm is to bring together the advantages of joint planning and joint learning while avoiding their disadvantages. Experimental results are provided that illustrate the potential benefits and shortcomings of the JPJL algorithm. 1 Motivation Multiagent Systems (MAS)---systems in which several interacting, intelligent and autonomous entities called agents pursue some set of goals or perform some set of tasks---have... | [
1107,
2321,
2877
] | Train |
1,140 | 2 | Mining the Web for Bilingual Text STRAND (Resnik, 1998) is a language- independent system for automatic discovery of text in parallel translation on the World Wide Web. This paper extends the preliminary STRAND results by adding automatic language identification, scaling up by orders of magnitude, and formally ewluating performance. The most recent end-product is an automaticaJly acquired parallel corpus comprising 2491 English-French document pairs, approximately 1.5 million words per language. | [
1361,
1495
] | Train |
1,141 | 4 | Towards a Virtual Operating Environment - Exploring Immersive Virtual Interface Design Using a Simple VR Image Viewer This paper explores the virtual interface from a design perspective. A simple virtual reality image viewer application is tested with a variety of users, producing a virtual interface design reference model, and a set of virtual interface design guidelines. 2 Acknowledgements A massive thank you to Shaun Bangay, my supervisor, for priceless guidance. Thank you to Mike Rorke for help within the CoRgi system and as an expert user, Fred Fourie for help with 3D Studio Max and the CoRgi ase readers, and Colin Dembovski for collision detection that always did work. Thanks also to the Rhodes VRSIG members, all the testers, the CoRgi documentation team and Phatwax. 3 Contents 1 Introduction 7 1.1 Problem Statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 1.2 Introduction to Virtual Reality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 1.3 Research Goals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... | [
1793,
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] | Train |
1,142 | 1 | Guided Crossover: A New Operator for Genetic Algorithm Based Optimization Genetic algorithms (GAs) have been extensively used in different domains as a means of doing global optimization in a simple yet reliable manner. They have a much better chance of getting to global optima than gradient based methods which usually converge to local sub optima. However, GAs have a tendency of getting only moderately close to the optima in a small number of iterations. To get very close to the optima, the GA needs a very large number of iterations. Whereas gradient based optimizers usually get very close to local optima in a relatively small number of iterations. In this paper we describe a new crossover operator which is designed to endow the GA with gradient-like abilities without actually computing any gradients and without sacrificing global optimality. The operator works by using guidance from all members of the GA population to select a direction for exploration. Empirical results in two engineering design domains and across both binary and floating point representa... | [
1988
] | Train |
1,143 | 0 | Jinni: Intelligent Mobile Agent Programming at the Intersection of Java and Prolog . Jinni (Java INference engine and Networked Interactor), is a lightweight, multi-threaded, logic programming language, intended to be used as a flexible scripting tool for gluing together knowledge processing components and Java objects in distributed applications. Jinni threads are coordinated through blackboards, local to each process. Associative search based on term unification (a variant of Linda) is used as the basic synchronization mechanism. Threads are controlled with tiny interpreters following a scripting language based on a subset of Prolog. Mobile threads, implemented by capturing first order continuations in a compact data structure sent over the network, allow Jinni to interoperate with remote high performance BinProlog servers for CPU-intensive knowledge processing and with other Jinni components over the Internet. The synergy of these features makes Jinni a convenient development platform for distributed AI, and in particular, for building intelligent autonomous agent... | [
1192,
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] | Train |
1,144 | 3 | Temporal Matching under Uncertainty Temporal matching is the problem of matching observations to predefined temporal patterns or templates. This problem arises in many applications including medical and model-based diagnosis, plan-recognition, and temporal databases. This work examines the sources of uncertainty in temporal matching and presents a probabilistic technique to perform temporal matching under uncertainty. This technique is then applied to the problem of finding the onset of infection with Toxoplasma Gondii. 1 Introduction Temporal matching is the process of matching a limited set of observations to known temporal evolution patterns in order to identify the stage of evolution or determine the onset of the temporally evolving pattern. Given a sequence of observations, and some temporal evolution patterns, a temporal match consistent with the sequence of observations maps observation times to particular points in a pattern. Formally, S is a set of states, TR is the set of time points measured rel... | [
2606
] | Test |
1,145 | 0 | Intelligent Driving Agents: The Agent Approach to Tactical Driving in Autonomous Vehicles and Traffic Simulation Computer traffic simulation is important for making new traffic-control strategies. Microscopic traffic simulators can model traffic flow in a realistic manner and are ideal for agent-based vehicle control. In this paper we describe a model of a reactive agent that is used to control a simulated vehicle. The agent is capable of tactical-level driving and has different driving styles. To ensure fast reaction times, the agent's driving task is divided in several competing and reactive behaviour rules. The agent is implemented and tested in a prototype traffic simulator program. The simulator consists of an urban environment with multi-lane roads, intersections, traffic lights, light controllers and vehicles. Every vehicle is controlled by a driving agent and all agents have individual behaviour settings. Preliminary experiments have shown that the agents exhibit human-like behaviour ranging from slow and careful to fast and aggressive driving behaviour. | [
2364
] | Train |
1,146 | 2 | Knowledge Retrieval and the World Wide Web }) )$ Figure 5. Images, knowledge indexations, and a customized query interface contained within one document. The sample query shows how the command spec, which looks for specializations of a conceptual graph, can be used to retrieve images CGs indexed. (Figure 7 gives the results.) [Cat]->(On)->[Table]. In WordNet, cat has five meanings (feline, gossiper, x-ray, beat, and vomit), and table has five meanings (array, furniture, tableland, food, and postpone) . In the WebKB ontology, the relation type On connects a concept of type Spatial_entity to another concept of the same type. Thus, WebKB can infer that beat and vomit are not the intended meanings for cat, and array and postpone are not the intended meanings for table. To further identify the intended meanings, WebKB could prompt the following questions to the user: "Does cat refer to feline, gossiper, x-ray, or something else?" and "Does table refer to furniture, tableland, food, or something else?" Finally, knowledge state... | [
1736,
1821,
2284
] | Train |
1,147 | 3 | A Critical Note on Stable Model Semantics In this paper, we argue that both the stable model semantics and its three-valued version are conceptually flawed. 1 Introduction The semantics of logic programming and deductive databases has been extensively studied in the past two decades. A whole spectrum of semantic theories for logic programs have been proposed, ranging from those that infer very little information from a logic program ("skeptical") to those that infer a great deal ("credulous"). The most skeptical semantics is the well-founded semantics [4] while the most credulous is the the stable model semantics [6] and its different but equivalent three-valued versions, including 3-stable models [8], partial stable models [9] and preferred extensions [2]. The chief drawback of the stable semantics is that a two-valued stable model is not defined for all logic programs. In the three-valued variant a model is always defined but that model may leave all atoms undetermined [8]. The original problem of the non-existence of a ... | [
2023,
2725
] | Test |
1,148 | 4 | DAB: Interactive Haptic Painting with 3D Virtual Brushes We present a novel painting system with an intuitive haptic interface, which serves as an expressive vehicle for interactively creating painterly works. We introduce a deformable, 3D brush model, which gives the user natural control of complex brush strokes. The force feedback enhances the sense of realism and provides tactile cues that enable the user to better manipulate the paint brush. We have also developed a bidirectional, two-layer paint model that, combined with a palette interface, enables easy loading of complex blends onto our 3D virtual brushes to generate interesting paint effects on the canvas. The resulting system, DAB, provides the user with an artistic setting, which is conceptually equivalent to a real-world painting environment. Several users have tested DAB and were able to start creating original art work within minutes. | [
1364
] | Test |
1,149 | 0 | Engineering AgentSpeak(L): A Formal Computational Model Perhaps the most successful agent architectures, and certainly the best known, are those based on the Belief-Desire-Intention (BDI) framework. Despite the wealth of research that has accumulated on both formal and practical aspects of this framework, however, there remains a gap between the formal models and the implemented systems. In this paper, we build on earlier work by Rao aimed at narrowing this gap, by developing a strongly-typed, formal, yet computational model of the BDI-based AgentSpeak(L) language. AgentSpeak(L) is a programming language, based on the Procedural Reasoning System (PRS) and the Distributed Multi-Agent Reasoning System (dMARS), which determines the behaviour of the agents it implements. In developing the model, we add to Rao's work, identify some omissions, and progress beyond the description of a particular language by giving a formal specification of a general BDI architecture that can be used as the basis for providing further formal specifications of more sophisticated systems. | [
1329
] | Train |
1,150 | 2 | Monadic Queries over Tree-Structured Data Monadic query languages over trees currently receive considerable interest in the database community, as the problem of selecting nodes from a tree is the most basic and widespread database query problem in the context of XML. Partly a survey of recent work done by the authors and their group on logical query languages for this problem and their expressiveness, this paper provides a number of new results related to the complexity of such languages over so-called axis relations (such as "child" or "descendant") which are motivated by their presence in the XPath standard or by their utility for data extraction (wrapping). | [
201,
1568,
2661
] | Validation |
1,151 | 0 | Modelling and Design of Multi-Agent Systems Abstract. Agent technologies are now being applied to the development of large-scale commercial and industrial software systems. Such systems are complex, involving hundreds, perhaps thousands of agents, and there is a pressing need for system modelling techniques that permit their complexity to be e ectively managed, and principled methodologies to guide the process of system design. Without adequate techniques to support the design process, such systems will not be su ciently reliable, maintainable or extensible, will be di cult to comprehend, and their elements will not be re-usable. In this paper, we present techniques for modelling agents and multi-agent systems which adapt and extend existing Object-Oriented representation techniques, and a methodology which provides a clear conceptual framework to guide system design and speci cation. We have developed these techniques for systems of agents based upon a particular Belief-Desire-Intention architecture, but have soughttoprovide a framework for the description of agent systems that is su ciently general to be applicable to other agent architectures, and which may be extended in various ways. 1 | [
1158,
1309,
2309,
2343
] | Train |
1,152 | 2 | Automatic Text Summarization of Multiple Documents Scientists have retrieved what appear to be normal human eggs from human ovarian tissue that was grafted onto research mice. This is the first research group to obtain mature, potentially fertilizable eggs. Results of the research are being presented today at the conference of the European Society of Human Reproduction and Embryology. A report published last year demonstrated that ovarian tissue which was frozen and then replaced into a woman's body resulted in ovulation and menstruation. Such methods are being considered for women being treated for cancer with methods that would severely diminish or destroy their reproductive chances. However, there is concern that the retransplanted tissue might contain cancer cells. The current study proposes to reduce that risk. This is yet another step toward enabling women to freeze ovarian tissue in their early 20's, when it is generally most productive, to delay reproduction until their later years. | [
788,
1241,
1640,
2407
] | Train |
1,153 | 3 | Accurate Estimation of the Cost of Spatial Selections Optimizing queries that involve operations on spatial data requires estimating the selectivity and cost of these operations. In this paper, we focus on estimating the cost of spatial selections, or window queries, where the query windows and data objects are general polygons. Cost estimation techniques previously proposed in the literature only handle rectangular query windows over rectangular data objects, thus ignoring the very significant cost of exact geometry comparison (the refinement step in a “filter and refine” query processing strategy). The cost of the exact geometry comparison depends on the selectivity of the filtering step and the average number of vertices in the candidate objects identified by this step. In this paper, we introduce a new type of histogram for spatial data that captures the complexity and size of the spatial objects as well as their location. Capturing these attributes makes this type of histogram useful for accurate estimation, as we experimentally demonstrate. We also investigate sampling-based estimation approaches. Sampling can yield better selectivity estimates than histograms for polygon data, but at the high cost of performing exact geometry comparisons for all the sampled objects. 1. | [
153,
2435
] | Train |
1,154 | 2 | Programming by Demonstration for Information Agents this article we will refer to the user in the female form, while the agent will be referred to using male forms. | [
897,
3149
] | Train |
1,155 | 0 | 3D Spatial Layouts Using A-Teams Spatial layout is the problem of arranging a set of components in an enclosure such that a set of objectives and constraints is satisfied. The constraints may include non-interference of objects, accessibility requirements and connection cost limits. Spatial layout problems are found primarily in the domains of electrical engineering and mechanical engineering in the design of integrated circuits and mechanical or electromechanical artifacts. Traditional approaches include ad-hoc (or specialized) heuristics, Genetic Algorithms and Simulated Annealing. The A-Teams approach provides a way of synergistically combining these approaches in a modular agent based fashion. A-Teams are also open to the addition of new agents. Modifications in the task requirements translate to modifications in the agent mix. In this paper we describe how modular A-Team based optimization can be used to solve 3 dimensional spatial layout problems. | [
1985
] | Train |
1,156 | 4 | Smart-Its Friends: A Technique for Users to Easily Establish Connections between Smart Artefacts . Ubiquitous computing is associated with a vision of everything being connected to everything. However, for successful applications to emerge, it will not be the quantity but the quality and usefulness of connections that will matter. Our concern is how qualitative relations and more selective connections can be established between smart artefacts, and how users can retain control over artefact interconnection. We propose context proximity for selective artefact communication, using the context of artefacts for matchmaking. We further suggest to empower users with simple but effective means to impose the same context on a number of artefacts. To prove our point we have implemented Smart-Its Friends, small embedded devices that become connected when a user holds them together and shakes them. 1 | [
681,
1653,
2118,
2278,
3087
] | Train |
1,157 | 0 | CaseLP, A Rapid Prototyping Environment For Agent Based Software Intelligent agents and multi-agent systems are increasingly recognized as an innovative approach for analyzing, designing and implementing complex, heterogeneous and distributed software applications. The agent-based view offers a powerful and high level conceptualization that software engineers can exploit to considerably improve the way in which software is realized. Agent-based software engineering is a recent and very interesting research area. Due to its novelty, there is still no evidence of well-established practices for the development of agent-based applications and thus experimentation in this direction is very important. This dissertation | [
1054,
1076,
1297,
2160,
2343,
2629,
2985
] | Test |
1,158 | 0 | Agent-Oriented Software Engineering Agent-oriented techniques represent an exciting new means of analysing, designing and building complex software systems. They have the potential to significantly improve current practice in software engineering and to extend the range of applications that can feasibly be tackled. Yet, to date, there have been few serious attempts to cast agent systems as a software engineering paradigm. This paper seeks to rectify this omission. Specifically, it will be argued that: (i) the conceptual apparatus of agent-oriented systems is well-suited to building software solutions for complex systems and (ii) agent-oriented approaches represent a genuine advance over the current state of the art for engineering complex systems. Following on from this view, the major issues raised by adopting an agent-oriented approach to software engineering are highlighted and discussed. | [
185,
567,
1151,
1232,
1829,
2364,
2576,
2819,
2944
] | Train |
1,159 | 2 | Discriminant-EM Algorithm with Application to Image Retrieval In many vision applications, the practice of supervised learning faces several difficulties, one of which is that insufficient labeled training data result in poor generalization. In image retrieval, we have very few labeled images from query and relevance feedback so that it is hard to automatically weight image features and select similarity metrics for image classification. This paper investigates the possibility of including an unlabeled data set to make up the insufficiency of labeled data. Different from most current research in image retrieval, the proposed approach tries to cast image retrieval as a transductive learning problem, in which the generalization of an image classifier is only defined on a set of images such as the given image database. Formulating this transductive problem in a probabilistic framework, the proposed algorithm, Discriminant-EM (D-EM), not only estimates the parameters of a generative model, but also finds a linear transformation to relax the assumption of pro... | [
224,
855,
1386,
1973,
2808,
2889,
3031
] | Test |
1,160 | 1 | Learning to Detect Salient Objects in Natural Scenes Using Visual Attention In the primate's visual system, selective attention rapidly selects conspicuous image locations to be analyzed in more details. Such selection is guided by several low-level feature extraction mechanisms, which detect candidate salient locations based on their local properties for a given feature type (e.g., intensity, color, orientation or motion). One difficulty which arises is how the information from different modalities should be combined into a single "saliency map" controlling where visual attention should be focused. Here, we quantitatively compare three feature combination strategies (simple summation, learned linear summation, and contents-based non-linear normalization) using three databases of natural color images. 1 Introduction Bottom-up or saliency-based visual attention allows primates to detect, in real time, nonspecific conspicuous targets from cluttered visual environments. Reproducing such nonspecific target detection capability in artificial systems has important ... | [
447
] | Validation |
1,161 | 2 | Combining Collaborative Filtering with Personal Agents for Better Recommendations Information filtering agents and collaborative filtering both attempt to alleviate information overload by identifying which items a user will find worthwhile. Information filtering (IF) focuses on the analysis of item content and the development of a personal user interest profile. Collaborative filtering (CF) focuses on identification of other users with similar tastes and the use of their opinions to recommend items. Each technique has advantages and limitations that suggest that the two could be beneficially combined. This paper shows that a CF framework can be used to combine personal IF agents and the opinions of a community of users to produce better recommendations than either agents or users can produce alone. It also shows that using CF to create a personal combination of a set of agents produces better results than either individual agents or other combination mechanisms. One key implication of these results is that users can avoid having to select among ag... | [
220,
1189,
2033,
2300,
2631,
3003
] | Test |
1,162 | 0 | Verbal and Nonverbal Discourse Planning this paper we first describe our enriched discourse generator explaining the 2 sets of rules (trigger and regulation) we have added. We also review the di#erent types of gaze communicative acts. Finally we present the variables defining the context and how they modify the computation of the display of the communicative acts. | [
569,
2892,
2992,
3174
] | Validation |
1,163 | 0 | A Multi-threaded Approach to Simulated Soccer Agents for the RoboCup Competition To meet the timing requirements set by the RoboCup soccer server simulator, this paper proposes a multi-threaded approach to simulated soccer agents for the RoboCup competition. At its higher level each agent works at three distinct phases: sensing, thinking and acting. Instead of the traditional single threaded approaches, POSIX threads have been used here to break down these phases and implement them concurrently. The details of how this parallel implementation can significantly improve the agent's responsiveness and its overall performance are described. Implementation results show that a multi-threaded approach clearly outperforms a singlethreaded one in terms of efficiency, responsiveness and scalability. The proposed approach will be very efficient in multi-processor systems. 1. Introduction The creation of the robotic soccer, the robot world cup initiative (RoboCup), is an attempt to foster AI and intelligent robotics research by providing a standard problem where wide range o... | [
750,
3001,
3173
] | Test |
1,164 | 2 | Using Software Agents to Support Evolution of Distributed Workflow Models This paper outlines a high-level design of how software agents can be used combined with an existing CAGIS Process Centred Environment to deal with evolution of distributed, fragmented workflow models. Our process centred environment allows process fragments of the same workflow model to be located in workspaces that are geographically distributed. These process fragments can be changed independently in local workspaces causing consistency problems. We propose to use software mobile agents, offering awareness services solving conflicting updates of process fragment. Our solution is illustrated using some scenarios. Keywords: Process centred environments, software agents, workflow model consistency, workflow model evolution, distribution, fragmentation. 1 Introduction Dealing with evolution of workflow processes is not a trivial matter. One simple solution to this problem is to have one centralised workflow model, that cannot be changed after it is instanciated. In practice, it is ho... | [
1392
] | Validation |
1,165 | 4 | Toward Computer-Based Support of Meta-Cognitive Skills: a Computational Framework to Coach Self-Explanation this paper, we describe how these solutions have been implemented in a computer tutor that coaches self-explanation within Andes, a tutoring system for Newtonian physics. We also present the results of a formal study to evaluate the usability and effectiveness of the system. Finally, we discuss some hypotheses to explain the obtained results, based on the analysis of the data collected during the study. INTRODUCTION Research on Intelligent Tutoring Systems (ITS) has been increasingly affecting education. While for many years ITS remained confined to research labs, today they have started moving into the classroom, showing their effectiveness for learning and influencing the structure of traditional curricula (Koedinger, Anderson, H., & Mark, 1995). However, existing ITS still target only a limited part of the learning process. They generally focus on teaching problem solving and domain specific cognitive skills. The long-term goal of our research is to explore innovat | [
393,
2788
] | Train |
1,166 | 0 | On Securely Scheduling A Meeting When people want to schedule a meeting, their agendas must be compared to find a time suitable for all participants. At the same time, people want to keep their agendas private. This paper presents several approaches which intend to solve this contradiction. A custom-made protocol for secure meeting scheduling and a protocol based on secure distributed computing are discussed. The security properties and complexity of these protocols are compared. A trade-off between trust and bandwidth requirements is shown to be possible by implementing the protocols using mobile agents. Keywords: mobile agents, secure distributed computation, meeting scheduling 1. | [
2667
] | Train |
1,167 | 2 | Building Efficient and Effective Metasearch Engines Frequently a user's information needs are stored in the databases of multiple search engines. It is inconvenient and inefficient for an ordinary user to invoke multiple search engines and identify useful documents from the returned results. To support unified access to multiple search engines, a metasearch engine can be constructed. When a metasearch engine receives a query from a user, it invokes the underlying search engines to retrieve useful information for the user. Metasearch engines have other benefits as a search tool such as increasing the search coverage of the Web and improving the scalability of the search. In this article, we survey techniques that have been proposed to tackle several underlying challenges for building a good metasearch engine. Among the main challenges, the database selection problem is to identify search engines that are likely to return useful documents to a given query. The document selection problem is to determine what documents to retrieve from each identified search engine. The result merging problem is to combine the documents returned from multiple search engines. We will also point out some problems that need to be further researched. | [
471,
488,
521,
587,
1059,
1120,
1125,
1134,
1308,
1415,
1642,
1888,
2275,
2464,
2503
] | Validation |
1,168 | 3 | An Experimental CLP Platform for Integrity Constraints and Abduction Integrity constraint and abduction are important in query-answering systems for enhanced query processing and for expressing knowledge in databases. A straightforward characterization of the two is given in a subset of the language CHR _ , originally intended for writing constraint solvers to be applied for CLP languages. This subset has a strikingly simple computational model that can be executed using existing, Prolog-based technology. Together with earlier results, this confirms CHR _ as a multiparadigm platform for experimenting with combinations of top-down and bottom-up evaluation, disjunctive databases and, as shown here, integrity constraint and abduction 1 Introduction Constraint logic programming (CLP) [10] is established as an extension to logic programming that adds higher expressibility and in some cases more efficient query evaluation. CLP has also given rise to a field of constraint databases [14]. In the present paper, we suggest CLP techniques applied for defini... | [
1325,
1828,
2239
] | Train |
1,169 | 3 | Knowledge Discovery from Client-Server Databases . The subject of this paper is the implementation of knowledge discovery in databases. Specifically, we assess the requirements for interfacing tools to client-server database systems in view of the architecture of those systems and of "knowledge discovery processes". We introduce the concept of a query frontier of an exploratory process, and propose a strategy based on optimizing the current query frontier rather than individual knowledge discovery algorithms. This approach has the advantage of enhanced genericity and interoperability. We demonstrate a small set of query primitives, and show how one example tool, the well-known decision tree induction algorithm C4.5, can be rewritten to function in this environment. 1 Introduction Relational databases are the current dominant database technology in industry, and many organizations have collected large amounts of data in so-called data warehouses expressly for the purpose of decision support and data mining. In general the data must ... | [
2159
] | Validation |
1,170 | 2 | WebBase : A repository of web pages In this paper, we study the problem of constructing and maintaining a large shared repository of web pages. We discuss the unique characteristics of such a repository, propose an architecture, and identify its functional modules. We focus on the storage manager module, and illustrate how traditional techniques for storage and indexing can be tailored to meet the requirements of a web repository. To evaluate design alternatives, we also present experimental results from a prototype repository called WebBase, that is currently being developed at Stanford University. Keywords : Repository, WebBase, Architecture, Storage management 1 Introduction A number of important applications require local access to substantial portions of the web. Examples include traditional text search engines [Google] [Avista], related page services [Google] [Alexa], and topic-based search and categorization services [Yahoo]. Such applications typically access, mine or index a local cache or repository of web... | [
298,
538,
752,
925,
1750,
1815,
1909,
2433,
2503,
2699,
3073
] | Test |
1,171 | 4 | MIA - An Ubiquitous Multi-Agent Web Information System This paper gives a brief overview about AI methods and techniques we have developed for building ubiquitous web information systems. These methods from areas of machine learning, logic programming, knowledge representation and multi-agent systems are discussed in the context of our prototypical information system MIA. MIA is a web information system for mobile users, who are equipped with a PDA (Palm Pilot), a cellular phone and a GPS device or cellular WAP phone. It captures the main issues of ubiquitous computing: location awareness, anytime information access and PDA technology. 1 Introduction Nowadays, the biggest but also the most chaotic and unstructured source of information is the World-WideWeb. Making this immense amount of information available for ubiquitous computing in daily life is a great challenge. Besides hardware issues for wireless ubiquitous computing, that still are to be solved (wireless communication, blue-tooth technologies, wearable computing units, integrat... | [
327,
439,
1569,
3098
] | Train |
1,172 | 0 | Specifying Agent Behavior as Concurrent Tasks Approved for public release; distribution unlimited Software agents are currently the subject of much research in many interrelated fields. While much of the agent community has concentrated on building exemplar agent systems, defining theories of agent behavior and inter-agent communications, there has been less emphasis on defining the techniques required to build practical agent systems. While many agent researchers refer to tasks performed by roles within a multiagent system, few really define the what they mean by tasks. We believe that the definition of tasks is critical in order to completely define what an agent within a multiagent system. Tasks not only define the types of internal processing an agent must do, but also how interactions with other agents relate to those internal processes. In this report, we define concurrent tasks, which specify a single thread of control that defines a task that the agent can perform and integrates inter-agent as well as intra-agent interactions. We typically think of concurrent tasks as defining how a role decides what actions to take, not necessarily what the agent does. This is an important distinction when talking about agents since hard-coding specific behavior may not be the ideal case. Often agents incorporate the concept of plans and planning to | [
1289,
1759,
2696
] | Validation |
1,173 | 0 | Agent-Based Distance Vector Routing Mobile Agents are being proposed for an increasing variety of applications. Distance Vector Routing (DVR) is an example of one application that can benefit from an agent-based approach. DVR algorithms, such as RIP, have been shown to cause considerable network resource overhead due to the large number of messages generated at each host/router throughout the route update process. Many of these messages are wasteful since they do not contribute to the route discovery process. However, in an agent-based solution, the number of messages is bounded by the number of agents in the system. In this paper, we present an agent-based solution to DVR. In addition, we will describe agent migration strategies that improve the performance of the route discovery process, namely Random Walk and Structured Walk. | [
86,
278,
1515
] | Test |
1,174 | 5 | Sensor Fault Detection and Identification in a Mobile Robot Multiple model adaptive estimation (MMAE) is used to detect and identify sensor failures in a mobile robot. Each estimator is a Kalman filter with a specific embedded failure model. The filter bank also contains one filter which has the nominal model embedded within it. The filter residuals are postprocessed to produce a probabilistic interpretation of the operation of the system. The output of the system at any given time is the confidence in the correctness of the various embedded models. As an additional feature the standard assumption that the measurements are available at a constant, common frequency, is relaxed. Measurements are assumed to be asynchronous and of varying frequency. The particularly difficult case of 'soft' sensor failure is also handled successfully. A system architecture is presented for the general problem of failure detection and identification in mobile robots. As an example, the MMAE algorithm is demonstrated on a Pioneer I robot in the case of three different sensor failures. | [
1253
] | Test |
1,175 | 3 | Extracting Collocations from Text Corpora A collocation is a habitual word combination. Collocational knowledge is essential for many tasks in natural language processing. We present a method for extracting collocations from text corpora. By comparison with the SUSANNE corpus, we show that both high precision and broad coverage can be achieved with our method. Finally, we describe an application of the automatically extracted collocations for computing word similarities. | [
2424
] | Train |
1,176 | 2 | Revisiting and Versioning in Virtual Special Reports Adaptation/personalization is one of the main issues for web applications and require large repositories. Creating adaptive web applications from these repositories requires to have methods to facilitate web application creation and management and to ensure reuse, sharing and exchange of data through the internet/intranet. Virtual documents deal with these issues. In our framework, we are interested in adaptive virtual documents for author-oriented web applications providing several reading strategies to readers. These applications have the following characteristics: authors have know-how which enables them to choose document contents and to organize them in one or more consistent ways. A reading strategy and the corresponding content are semantically coherent and convey a particular meaning to the readers. Such author's know-how can be represented at knowledge level and then be used for generating web documents dynamically, for ensuring reader comprehension and for sharing and reuse. Then an adaptive virtual document can be computed on the fly by means of a semantic composition engine using: i) an overall document structure -- for instance a narrative structure - representing a reading strategy for which node contents are linked at run time, according to user's needs for adaptation, ii) an intelligent search engine and semantic metadata relying on semantic web initiative, and iv) a user model. In this paper, we focus on a semantic composition engine enabling us to compute on the fly adaptive/personalized web documents in the ICCARS project. Its main goal is to assist the journalist in building adaptive special reports. In such a framework, adaptation, personalization and reusability are central issues for delivering adaptive special reports. | [
512
] | Validation |
1,177 | 3 | Estimating Frequency of Change Many online data sources are updated autonomously and independently. In this paper, we make the case for estimating the change frequency of the data, to improve web crawlers, web caches and to help data mining. We first identify various scenarios, where different applications have different requirements on the accuracy of the estimated frequency. Then we develop several "frequency estimators" for the identified scenarios. In developing the estimators, we analytically show how precise/effective the estimators are, and we show that the estimators that we propose can improve precision significantly. 1 Introduction With the explosive growth of the internet, many data sources are available online. Most of the data sources are autonomous and are updated independently of the clients that access the sources. For instance, popular news web sites, such as CNN and NY Times, update their contents periodically, whenever there are new developments. Also, many online stores update the price/availab... | [
806
] | Train |
1,178 | 1 | Application Of Machine Learning To Robotics - An Analysis Robotics is one of the most challenging applications of Machine Learning (ML) techniques. It is characterized by direct interaction with a real world, sensory feedback and an enormous complexity of the control system. In recent years several approaches to apply ML to specific robotics tasks have been published. Nevertheless we are still far from a complete autonomous robot control system with learning components. This paper aims at pointing out the problems and possible applications for integrating learning capabilities into a robot control system and then describes a new integrated system architecture which shows up a set of components necessary for (partially) autonomous systems with learning facilities. 1. Introduction In recent years there has been an increasing interest in applying machine learning techniques to robotics. The applications are manipulator as well as mobile system tasks. The learning techniques used range from rote learning [25, 22, 1, 8, 27] and inductive learning... | [
1831
] | Test |
1,179 | 3 | Efficient Support for P-HTTP in Cluster-Based Web Servers This paper studies mechanisms and policies for supporting HTTP/1.1 persistent connections in cluster-based Web servers that employ content-based request distribution. We present two mechanisms for the efficient, content-based distribution of HTTP/1.1 requests among the back-end nodes of a cluster server. A trace-driven simulation shows that these mechanisms, combined with an extension of the locality-aware request distribution (LARD) policy, are effective in yielding scalable performance for HTTP/1.1 requests. We implemented the simpler of these two mechanisms, back-end forwarding. Measurements of this mechanism in connection with extended LARD on a prototype cluster, driven with traces from actual Web servers, confirm the simulation results. The throughput of the prototype is up to four times better than that achieved by conventional weighted round-robin request distribution. In addition, throughput with persistent connections is up to 26% better than without. | [
2116
] | Validation |
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