The paper introduces an algorithm for personalized clustering based on a range tree structure, used for identifying all web documents satisfying a set of predefined personal user preferences. The returned documents go...
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ISBN:
(纸本)1595934537
The paper introduces an algorithm for personalized clustering based on a range tree structure, used for identifying all web documents satisfying a set of predefined personal user preferences. The returned documents go through a clustering phase before reaching the end user, thus allowing more effective manipulation and supporting the decision making process. The proposed algorithm demonstrates increased applicability in semantic web settings, since they offer the infrastructure for the explicit declaration of web document attributes and their respective values, thus allowing for more automated retrieval. The proposed algorithm improves the k-means range algorithm, as it uses the already constructed range tree (i.e. during the personalized filtering phase) as the basic structure on which the clustering step is based, applying instead of the k-means, the k-windows algorithm. The total number of parameters used for modeling the web documents dictates the number of dimensions of the Euclidean space representation. The time complexity of the algorithm is O(log d-2n+v), where d is the number of dimensions, n is the total number of web documents and v is the size of the answer. Copyright 2006 ACM.
In this poster, we present an approach to contex-tualized semantic image annotation as an optimization problem. Ontologies are used to capture general and contextual knowledge of the domain considered, and a genetic a...
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In this poster, we present an approach to contex-tualized semantic image annotation as an optimization problem. Ontologies are used to capture general and contextual knowledge of the domain considered, and a genetic algorithm is applied to realize the final annotation. Experiments with images from the beach vacation domain demonstrate the performance of the proposed approach and illustrate the added value of utilizing contextual information.
In this work Statistical Graphical Language Models (SGLMs), a technique adapted from Statistical Language Models (SLMs), are applied to the task of graphical object recognition. SLMs are used in Natural Language Proce...
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ISBN:
(纸本)9781932415957
In this work Statistical Graphical Language Models (SGLMs), a technique adapted from Statistical Language Models (SLMs), are applied to the task of graphical object recognition. SLMs are used in Natural Language Processing for tasks such as Speech Recognition and Information Retrieval. SGLMs view graphical objects as belonging to graphical languages and use this view to compute probabilistic distributions of graphical objects within graphical documents. SGLMs such as N-grams require large corpora of training data, which consist of graphical objects in contextual use (real world graphical documents). Constructing corpora is an important stage in developing the models and many issues need to be addressed. This paper discusses the development of graphical corpora and presents approaches to some of the problems encountered.
In this paper the authors present an overview of techniques and tools that enable the effective evaluation and refactoring of a Web application's conceptual schema. Moreover, based on the introduction of the notio...
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ISBN:
(纸本)0889865744
In this paper the authors present an overview of techniques and tools that enable the effective evaluation and refactoring of a Web application's conceptual schema. Moreover, based on the introduction of the notion of model clones (in a previous work), as partial conceptual schemas that are repeated within a broader application model and the notion of model smells, as certain blocks in the Web applications model that imply the possibility of refactoring, this paper illustrates a methodology and a tool for detecting and evaluating the existence of potential model clones, in order to identify problems in an application's conceptual schema by means of efficiency, consistency, usability and overall quality. The methodology can be deployed either in the process of designing an application or in the process of reengineering it. Evaluation is performed according to a number of inspection steps. At first level the compositions used in the hypertext design are evaluated, followed by a second level evaluation concerning data manipulation and presentation to the user.
In this work, we propose an obstacle model to be used while simulating wireless sensor networks. To the best of our knowledge, this is the first time such an integrated and systematic obstacle model appears. We define...
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In this work, we propose an obstacle model to be used while simulating wireless sensor networks. To the best of our knowledge, this is the first time such an integrated and systematic obstacle model appears. We define several types of obstacles that can be found inside the deployment area of a wireless sensor network and provide a categorization of these obstacles, based on their nature (physical and communication obstacles), their shape, as well as their nature to change over time. In light of this obstacle model, we conduct extensive simulations in order to study the effects of obstacles on the performance of representative data propagation protocols for wireless sensor networks. Our findings show that obstacle presence has a significant impact on protocol performance. Also, we demonstrate the effect of each obstacle type on different protocols, thus providing the network designer with advice on which protocol is best to use.
In this paper the impact of user's hand holding a Multiple-Input-Multiple- Output (MIMO) terminal on the system performance is investigated. A 4×4 MIMO system is considered with a Personal Digital Assistant (...
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ISBN:
(纸本)9290929375
In this paper the impact of user's hand holding a Multiple-Input-Multiple- Output (MIMO) terminal on the system performance is investigated. A 4×4 MIMO system is considered with a Personal Digital Assistant (PDA) terminal equipped with a compact array of 4 patch elements. The radiation patterns of the antenna elements are simulated in the presence of the other elements and in the presence of a user's hand. The obtained patterns are used to evaluate the covariance matrix of the receive antenna which is incorporated in a correlation-based MIMO channel model. MIMO channel capacity is calculated to demonstrate the capacity degradation caused by the user's hand.
Carefully designed and managed services are essential for quality-demanding traffic, especially in large-scale IP networks where the aggregation of flows and the variety of traffic types are extensive. Although indivi...
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Carefully designed and managed services are essential for quality-demanding traffic, especially in large-scale IP networks where the aggregation of flows and the variety of traffic types are extensive. Although individual mechanisms have been widely investigated, not much related work exists on integrated approaches to QoS provisioning that are also feasible to implement. This work presents a thorough approach to the design, dimensioning and provisioning of a high priority service for high-quality demanding traffic over an IP network. Our approach employs efficient scheduling and a dynamic admission control scheme while demonstrating novel characteristics in terms of the quality offered to IP flows.
The scheme of real time streaming video is one of the newcomers in wireless data communication, raising a number of new requirements in both telecommunication and data communication systems. This scheme is applied whe...
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The scheme of real time streaming video is one of the newcomers in wireless data communication, raising a number of new requirements in both telecommunication and data communication systems. This scheme is applied when the user experiences real time multimedia content. rate control is an important issue in video streaming applications for both wired and wireless networks. A widely accepted rate control method in wired networks is equation based rate control. In this work, we focus on a mechanism for equation based congestion control for video transmission over WCDMA networks. With our mechanism, the sender explicitly adjusts its sending rate as a function of the measured rate of loss events, the round trip time and the packet size. Furthermore, we examine the performance of UMTS air interface for real time video transmission using real time protocols, through a number of experiments.
It is known that multicasting is an efficient method of supporting group communication as it allows the transmission of packets to multiple destinations using fewer network resources. Thus, service providers are incre...
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It is known that multicasting is an efficient method of supporting group communication as it allows the transmission of packets to multiple destinations using fewer network resources. Thus, service providers are increasingly interested in supporting multicast communications over wireless networks and in particular over UMTS. Multicasting is a more efficient method of supporting group communication than unicasting or broadcasting, as it allows transmission and routing of packets to multiple destinations using fewer network resources. In this paper the three above mentioned methods of supporting group communication are analyzed in terms of their performance
In this paper, we present an adaptive and intelligent Web-based educational system that uses AI techniques for personalized assessment of the learners. More specifically, we focus on a mechanism for on-line creation o...
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In this paper, we present an adaptive and intelligent Web-based educational system that uses AI techniques for personalized assessment of the learners. More specifically, we focus on a mechanism for on-line creation of a user-adapted test, which can be used alongside the predetermined test. The user can ask for such a test any time he/she is willing to do so, even if he/she has not studied all predetermined concepts of a learning goal. A small rule base is used by an expert system inference engine for making decisions on the difficulty level of the exercises to be included in the test. This is based on the evaluation of the learner during concept studying. Adaptive assessment of the learner can be repeatedly used until there is no further need. Another small rule-base is used for deciding on whether a new test is suggested or not. This is based on the learner's previous test assessment results. Preliminary experimental results show that the users need less time to study a learning goal when using the adaptive assessment capability of the system
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