Chunghwa Telecommunication Laboratories

Taoyuan, Taiwan

Chunghwa Telecommunication Laboratories

Taoyuan, Taiwan
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Peng I.-H.,Minghsin University of Science and Technology | Lin M.-H.,National Central University | Lin M.-H.,Chunghwa Telecommunication Laboratories | Chen Y.-W.,Minghsin University of Science and Technology | And 2 more authors.
Proceedings - 2013 7th International Conference on Complex, Intelligent, and Software Intensive Systems, CISIS 2013 | Year: 2013

The video streaming service is one of the emerging services for network users. The network conveys various kinds of traffic to the users and different traffic classes always have different quality requirements. Therefore, it is a critical issue to allocate suitable network resource to suitable traffic class for better service quality provisioning and resource utilization. This paper considers the characteristics of video frames to forward the video packet in an efficient way. The proposed scheme properly utilizes the unused bits of the differential service (DS) field of the IP header to provide some heuristic information for packet early discarding. Thus, by using the opportunity random early dropping (RED) concept, the proposed packet correlated RED (PCRED) scheme refers the heuristic information to selectively drop useless packet that is not helpful for the improvement of receiving quality for better buffer and bandwidth utilization. Exhaustive simulations were conducted to compare the performance of the proposed scheme with the RED with in/out (RIO) and weighted RED (WRED) schemes. The simulation results show that the proposed scheme is superior to the other schemes for video streaming services. © 2013 IEEE.


Tung Y.-H.,Chunghwa Telecommunication Laboratories | Tung Y.-H.,National Chiao Tung University | Tseng S.-S.,National Chiao Tung University | Tseng S.-S.,Asia University, Taiwan | And 2 more authors.
Proceedings - International Conference on Quality Software | Year: 2010

As the quantity and breadth of Web-based software systems continue to grow rapidly, it is becoming critical to assure the quality and reliability of a Web application. Web application testing is a challenging work owing to its dynamic behaviors and complex dependencies. Test case generation, in general, is costly and labor-intensive processes. How to automatically generate effective test case is important for Web applications testing. In this paper, we propose the two-phase approach to generate test cases automatically by analyzing structure of the Web application. We define the dependence relationships, data dependence and control dependence, in the Web application and detect the relationships from source code and improve the way of test case generation with analysis result. The experimental result show that our approach can reduce test case set in test case generation processes. © 2010 IEEE.


Huang K.-C.,National Taichung University of Education | Shen B.-J.,National Taichung University of Education | Lee T.-J.,National Chung Hsing University | Chang H.-Y.,National Center for High Performance Computing | And 2 more authors.
CloudCom 2012 - Proceedings: 2012 4th IEEE International Conference on Cloud Computing Technology and Science | Year: 2012

Cloud computing has caused a revolution in our way of using software. Software development and deployment based on the new models of Software as a Service (SaaS) and Service-Oriented Architecture (SOA) are expected to bring a lot of benefits for users. However, software developers and software service providers will have to address new challenging issues before such benefits can be realized. The issues mainly arise from two characteristics of service-based applications: software based on distributed service flows and online concurrent user access. This paper deals with one of the important issues concerning resource allocation and dynamic provisioning for the deployed services in a cloud environment. We propose a service deployment strategy based on the structural property of application service flows and a dynamic resource provisioning mechanism utilizing the estimation of future service requests. A series of experiments were conducted on the CloudSim platform to evaluate the proposed mechanisms. The experimental results indicate that the proposed methods significantly outperform the commonly used primitive approaches, achieving up to 79.9% performance improvement. © 2012 IEEE.


Chang Y.-J.,University of Texas at Austin | Lee Y.-T.,ChungHwa Telecommunication Laboratories | Gao J.-R.,University of Texas at Austin | Wu P.-C.,University of Illinois at Urbana - Champaign | Wang T.-C.,National Tsing Hua University
IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems | Year: 2010

This paper presents a robust global router called NTHU-Route 2.0 that improves the solution quality and runtime of NTHU-Route by the following enhancements: 1) a new history based cost function; 2) new ordering methods for congested region identification and rip-up and reroute; and 3) two implementation techniques. We report convincing experimental results to show the effectiveness of each individual enhancement. With all these enhancements together, NTHU-Route 2.0 solves all ISPD98 benchmarks with very good quality. Moreover, NTHU-Route 2.0 routes 7 of 8 ISPD07 benchmarks and 12 of 16 ISPD08 benchmarks without any overflow. Compared with other state-of-the-art global routers, NTHU-Route 2.0 is able to produce better solution quality and/or run more efficiently. © 2006 IEEE.


Kuo J.-S.,Chunghwa Telecommunication Laboratories | Li H.,Institute for Infocomm Research
Information Processing and Management | Year: 2012

This paper conducts an inquiry into regional transliteration variants across Chinese speaking regions. We begin by studying the social association of regional transliterations, followed by postulating a computational model for effective transliteration extraction from the Web. In the computational model, we first propose constraint-based exploration by incorporating transliteration knowledge from transliteration modeling and predictive query suggestions from search engines into query formulation as constraints so as to increase the chance of desired transliteration returns in learning regional transliteration variants. Then, we study a cross-training algorithm, which explores the attainably helpful information of transliteration mappings across related regional corpora for the learning of transliteration models, to improve the overall extraction performance. The experimental results show that the proposed method not only effectively harvests a lexicon of regional transliteration variants but also mitigates the need of manual data labeling for transliteration modeling. We also carry out an investigation into the underlying characteristics of regional transliterations that motivate the cross-training algorithm. © 2011 Elsevier Ltd. All rights reserved.


Lu C.-Y.,Delin Institute of Technology | Wang S.-A.,Delin Institute of Technology | Cheng Y.-J.,Chunghwa Telecommunication Laboratories | Kuo S.-Y.,National Taiwan University
International Journal of Quantum Information | Year: 2010

In this paper, we propose a quantum secure direct communication (QSDC) protocol based on EinsteinPodolskyRosen (EPR) pairs. Previous QSDC protocols usually consume one EPR pair to transmit a single qubit. If Alice wants to transmit an n-bit message, she needs at least n/2 EPR pairs when a dense coding scheme is used. In our protocol, if both Alice and Bob preshare 2c + 1 EPR pairs with the trusted server, where c is a constant, Alice can transmit an arbitrary number of qubits to Bob. The 2c EPR pairs are used by Alice and Bob to authenticate each other and the remaining EPR pair is used to encode and decode the message qubit. Thus the total number of EPR pairs used for one communication is a constant no matter how many bits will be transmitted. It is not necessary to transmit EPR pairs before transmitting the secret message except for the preshared constant number of EPR pairs. This reduces both the utilization of the quantum channel and the risk. In addition, after the authentication, the server is not involved in the message transmission. Thus we can prevent the server from knowing the message. © 2010 World Scientific Publishing Company.


Yeh F.-H.,Tamkang University | Tsay H.-S.,Tamkang University | Yang C.-C.,Chunghwa Telecommunication Laboratories
Applied Mechanics and Materials | Year: 2014

In this paper, the auto-location head-controlled talking machine has been carried out using computer aided design to solve the problem of communication with the outside world for the visually impaired people with multiple disabilities. The talking machine makes use of the infrared ray sensors to receive the signals launched by shaking the infrared ray emitter on their heads. The communication functions of Pinyin, associating Chinese character, debugging error are processed based on the single chip processor 89C52. Then the signals are transmitted into a personal computer through the RS-232 or USB interface. The pronounced software of head-controlled talking machine is created using text-to-speech system to achieve the communication with other people. This study also develops auto-location function by the CCD tracing module to adjust the infrared ray sensor and increase the accuracy of the head-controlled talking machine. The results of this study can improve the ability of communication for visually impaired people with multiple disabilities. © (2014) Trans Tech Publications, Switzerland.


Yeh F.-H.,Tamkang University | Tsay H.-S.,Tamkang University | Yang C.-C.,Tamkang University | Yang C.-C.,Chunghwa Telecommunication Laboratories
Applied Mechanics and Materials | Year: 2014

In this paper, the optimum design and dynamic analysis of a new type of piezoelectric Braille display cell are studied by computer aided engineering software. At first, the design parameters of piezoelectric actuator are analyzed by finite element method to determine the position of fixed end and minimum voltage to actuate 0.7mm displacement and 15g output force. Then, the optimum design is performed according to the electric displacement 0.7mm, output force 15g, actuator length, position of fixed end and minimum voltage. Finally, Braille display cell is analyzed by dynamic simulation software. It shows that actuators take 0.0002 sec to upward achieve 0.7 mm displacement. The result of optimum design is reasonable in this paper which can be the reference for related research. © (2014) Trans Tech Publications, Switzerland.


Lin C.-H.,Chunghwa Telecommunication Laboratories | Wang W.-J.,Chunghwa Telecommunication Laboratories
European Signal Processing Conference | Year: 2015

An efficient method for speaker adaptation (SA) is proposed in this paper. Let the relationship between the mean parameters of adapted model and the mean parameters of the speaker independent (SI) model be represented by sets of linear transformations like that of maximum likelihood linear regression (MLLR) approach, we try to estimate the transformations by maximum a posteriori (MAP) criterion. The prior mean distribution is considered in the estimation. The experiments on Mandarin speech recognition show the proposed approach is superior to the MLLR approach when only little speech is available for speaker adaptation. © 2000 EUSIPCO.


Yeh F.-H.,Tamkang University | Yang C.-C.,Tamkang University | Yang C.-C.,Chunghwa Telecommunication Laboratories
Research in Developmental Disabilities | Year: 2014

This study proposed a new information and commutation technology assisted blind telephone interview (ICT-ABTI) system to help visually impaired people to do telephone interview jobs as normal sighted people and create more diverse employment opportunities for them. The study also used an ABAB design to assess the system with seven visually impaired people. As the results, they can accomplish 3070 effective telephone interviews per month independently. The results also show that working performance of the visually impaired can be improved effectively with appropriate design of operation working flow and accessible software. The visually impaired become productive, lucrative, and self-sufficient by using ICT-ABTI system to do telephone interview jobs. The results were also shared through the APEC Digital Opportunity Center platform to help visually impaired in Philippines, Malaysia and China. © 2014 Elsevier Ltd.

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