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 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.
Web services are becoming an important enabler of the Semantic Web. In this paper, we present a new P2P infrastructure for Web Services discovery. Peers that store Web Services information, such as data item descripti...
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Web services are becoming an important enabler of the Semantic Web. In this paper, we present a new P2P infrastructure for Web Services discovery. Peers that store Web Services information, such as data item descriptions, are efficiently located using a scalable and robust data indexing structure for Peer-to-Peer data networks, EST-GRID (Exponential Search Tree). EST-GRID provides support for processing Exact match Queries of the form "given a key, map the key onto a node". EST-GRID adapts efficiently update queries as nodes join and leave the system, and can answer queries even if the system is continuously changing. Results from theoretical analysis show that the communication cost of the query and update operations scaling both in O(√log n) time where n the number of nodes.
For monotone generated points on the plane we present the Dynamic Monotone Priority Search Tree (DMoPST) in main/external memory with O(1) update time/O(1) block transfers in worst-case. The external version of the st...
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For monotone generated points on the plane we present the Dynamic Monotone Priority Search Tree (DMoPST) in main/external memory with O(1) update time/O(1) block transfers in worst-case. The external version of the structure above promises efficient applications in transaction time Databases systems.
Positioning algorithms are of great importance in recent years, as the means of providing location based services (LBS) including wireless emergency services. Telecommunication engineers are frequently puzzled by the ...
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Positioning algorithms are of great importance in recent years, as the means of providing location based services (LBS) including wireless emergency services. Telecommunication engineers are frequently puzzled by the accuracy of the implemented technique in contrast with the cost. In this paper, we introduce a novel Time of Arrivals (TOA) location positioning method in GSM networks using three Base Stations (BSs). In order to implement the proposed solution an analytical explanation of the signaling flow is provided. The algorithm's accuracy is improved by introducing an additional weight coefficient reflecting the LOS/nLOS propagation. Finally, the cost function is simulated in a microcellular city centre environment and compared to Turin's. Moreover a reference is provided regarding the other methods of positioning.
Heart rate variability (HRV) is a marker of autonomous activity in the heart. An important application of HRV measures is the stratification of mortality risk after myocardial infarction. Our hypothesis is that the in...
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The increasing demand for wireless broadband service offering in long distances is the major drive behind the emergence of the WiMAX technology. WiMAX is targeted to providing high bit data rates to the end users in a...
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The increasing demand for wireless broadband service offering in long distances is the major drive behind the emergence of the WiMAX technology. WiMAX is targeted to providing high bit data rates to the end users in a wireless manner, any time, in any location, even in harsh environmental conditions and at an acceptable quality. This paper presents the experimental results of a WiMAX system that follows the specifications of IEEE 802.16-2004 standard. Throughput and Bit Error Rate (BER) measurements, as well as voice and video service experiments are carried out, leading to useful conclusions for the performance evaluation of the WiMAX system under test and the WiMAX technology in general.
Crosstalk is an important factor that needs to be considered and study its effects in copper wires, especially when voice communication takes place. Its presence has proven to be an impaired factor in the performance ...
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Crosstalk is an important factor that needs to be considered and study its effects in copper wires, especially when voice communication takes place. Its presence has proven to be an impaired factor in the performance of communication services. This paper measures the isolation losses and the crosstalk losses as a function of the frequency and the length of the copper wires. It also presents throughput results from modems designed in the context of an EU financed project that can provide a symmetric 100 Mbps over two pairs for reach up to 500m (5 times the existing reach of 100-BASE-T systems).
Ferroelectric materials have been gaining much interest over the last decades due to the unique operational characteristics they demonstrate, when a dc electric field is applied. This paper investigates the scattering...
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ISBN:
(纸本)9290929375
Ferroelectric materials have been gaining much interest over the last decades due to the unique operational characteristics they demonstrate, when a dc electric field is applied. This paper investigates the scattering analysis of electromagnetic waves from materials with high permittivity that follows a linear spatial variation along one axis. The Surface Integral Equation (SIE) and Volume Integral Equation (VIE) methods are invoked to compute the currents and the radar cross section (RCS). The number of unknowns for the VIE is, as expected, larger than for the SIE method. The RCS and the induced current are associated in such a way that one can approximate the linear variation with relatively few elements (unknowns).
Ferroelectric materials have been gaining much interest over the last decades due to the unique operational characteristics they demonstrate, when a dc electric field is applied. This paper investigates the scattering...
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Ferroelectric materials have been gaining much interest over the last decades due to the unique operational characteristics they demonstrate, when a dc electric field is applied. This paper investigates the scattering analysis of electromagnetic waves from materials with high permittivity that follows a linear spatial variation along one axis. The surface integral equation (SIE) and volume integral equation (VIE) methods are invoked to compute the currents and the radar cross section (RCS). The number of unknowns for the VIE is, as expected, larger than for the SIE method. The RCS and the induced current are associated in such a way that one can approximate the linear variation with relatively few elements (unknowns).
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