Browsing by Author "Huang, JL"

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An effective broadcast program generation algorithm for dependent data
(2005)
Huang, JL
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Peng, WC
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資訊工程學系
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Department of Computer Science
We explore in this paper the problem of broadcasting dependent data in multiple broadcast channels, and explicitly investigate the effect of data replication. By analyzing the model of dependent data broadcasting, we derive several theoretical properties for the average access time in a multiple channel environment. In light of the theoretical results, we develop an efficient heuristic algorithm to generate broadcast programs, which are designed for the environments with replication. Our experimental results show that the proposed algorithm is able to obtain solution broadcast programs of very high quality.
Carrier distribution and relaxation-induced defects of InAs/GaAs quantum dots
(2000-11-06)
Wang, JS
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Chen, JF
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Huang, JL
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Wang, PY
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Guo, XJ
The carrier distribution and defects have been investigated in InAs/GaAs quantum dots by cross-sectional transmission electron microscopy (XTEM), capacitance-voltage, and deep level transient spectroscopy. Carrier confinement is found for 1.1- and 2.3-monolayer-(ML)-thick InAs samples. For 2.3 ML sample, XTEM images show the presence of defect-free self-assembled quantum dots. With further increase of the InAs thickness to 3.4 ML, significant carrier depletion caused by the relaxation is observed. In contrast to 1.1 and 2.3 ML samples in which no traps are detected, two broad traps and three discrete traps at 0.54, 0.40, and 0.34 eV are observed in 3.4 ML sample. The traps at 0.54 and 0.34 eV are found to be similar to the traps observed in relaxed In0.2Ga0.8As/GaAs single quantum well structures. By comparing with the XTEM images, the trap at 0.54 eV is identified to be the relaxation-induced dislocation trap in the GaAs layer. (C) 2000 American Institute of Physics. [S0003-6951(00)02245-2].
Constructing an object-oriented architecture for Web application testing
(2002-01-01)
Yang, JT
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Huang, JL
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Wang, FJ
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Chu, WC
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資訊工程學系
The variety of existing web application frameworks has lead to the development of a wide range of Web applications for both the Internet and intranets. Web applications are constructed based on various frameworks ranging from simple HTML-based forms to complicated distributed-object computations based on Java and CORBA. Web software enables programmers to choose a proper framework for their own Web applications. The prevalence of Web-based applications has also led to the need to adapt software testing frameworks and tools for them, This study presents a software testing architecture that integrates several common but enhanced testing tools as a sub-architecture to fit a common Web application framework. The architecture reuses several software patterns and architectures from traditional testing environments. A Web application testing environment prototype is also constructed to demonstrate the feasibility of the proposed architecture.
Exploring regression for mining user moving patterns in a mobile computing system
(2005)
Hung, CC
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Peng, WC
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Huang, JL
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資訊工程學系
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Department of Computer Science
In this paper, by exploiting the log of call detail records, we present a solution procedure of mining user moving patterns in a mobile computing system. Specifically, we propose algorithm LS to accurately determine similar moving sequences from the log of call detail records so as to obtain moving behaviors of users. By exploring the feature of spatial-temporal locality, we develop algorithm TC to group call detail records into clusters. In light of the concept of regression, we devise algorithm MF to derive moving functions of moving behaviors. Performance of the proposed solution procedure is analyzed and sensitivity analysis on several design parameters is conducted. It is shown by our simulation results that user moving patterns obtained by our solution procedure are of very high quality and in fact very close to real user moving behaviors.
On exploring the power-law relationship in the itemset support distribution
(2006)
Chuang, KT
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Huang, JL
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Chen, MS
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資訊工程學系
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Department of Computer Science
We identify and explore in this paper an important phenomenon which points out that the power-law relationship appears in the distribution of itemset supports. Characterizing such a relationship will benefit many applications such as providing the direction of tuning the performance of the frequent- itemset mining. Nevertheless, due to the explosive number of itemsets, it will be prohibitively expensive to retrieve characteristics of the power-law relationship in the distribution of itemset supports. As such, we also propose in this paper a valid and cost-effective algorithm, called algorithm PPL, to extract characteristics of the distribution without the need of discovering all itemsets in advance. Experimental results demonstrate that algorithm PPL is able to efficiently extract the characteristics of the power-law relationship with high accuracy.
On the effect of group mobility to data replication in ad hoc networks
(2006-05-01)
Huang, JL
;
Chen, MS
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資訊工程學系
;
Department of Computer Science
The growth in wireless communication technologies attracts a considerable amount of attention in mobile ad hoc networks. Since mobile hosts in an ad hoc network usually move freely, the topology of the network changes dynamically and disconnection occurs frequently. These characteristics make it likely for a mobile ad hoc network to be separated into several disconnected partitions, and the data accessibility is hence reduced. Several schemes are proposed to alleviate the reduction of data accessibility by replicating data items. However, little research effort was elaborated upon exploiting the group mobility where the group mobility refers to the phenomenon that several mobile nodes tend to move together. In this paper, we address the problem of replica allocation in a mobile ad hoc network by exploring group mobility. We first analyze the group mobility model and derive several theoretical results. In light of these results, we propose a replica allocation scheme to improve the data accessibility. Several experiments are conducted to evaluate the performance of the proposed scheme. The experimental results show that the proposed scheme is able to not only obtain higher data accessibility, but also produce lower network traffic than prior schemes.
Population estimation for resource inventory applications over sensor networks
(2005)
Huang, JL
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資訊工程學系
;
Department of Computer Science
The growing advance in wireless communications and electronics makes the development of low-cost and low-power sensors possible. These sensors are usually small in size and are able to communicate with other sensors in short distances wirelessly. A sensor network consists of a number of sensors which cooperates with one another to accomplish some tasks. In this paper, we address the problem of resource inventory applications, which means a class of applications involving population calculation of a specific species or object type. To reduce energy consumption, each sensor only reports the number of sensed objects to the server, and the server will estimate the object number according to the received reports of all sensors. To address this problem, we design in this paper a population estimation algorithm, called algorithm Estimation, to estimate the object numbers. Several experiments are conducted to measure the performance of algorithm Estimation. The experimental results show that algorithm Estimation is able to obtain closer approximations of object numbers than prior algorithms.