Chih-Chin Liang

An effective approach for content delivery in an evolving intranet environment – a case study of the largest telecom company in taiwan

Being the dominant telecommunication company in Taiwan, ChungHwa Telecom Co., Ltd., CHT is her symbol listed on the New York Stock Exchange, provides major communication services to more than 23 million people living in Taiwan. CHT has vast number of software developed on client-server or web-based architectures with client software installed in more than ten thousand client computers spreading over the entire nation. Since telecommunication industry evolved in fast pace, the software functions are constantly changing. The changes have to be reflected in all client software before new services can be launched. Thus, the cost and time in distributing contents to client computers has become a major concern in CHT. To improve the efficiency of contents distribution, this research helps CHT develop new software to automatically distribute contents to client computers. To minimize the chance of system locks and balance contents distribution loading, in the new system, each dispatching server sends update contents to no more than three other servers. The contents are delivered with hybrid routing strategy that combines both fixed and adaptive routing strategies. With its low error rate and speedy distribution, the new system reduces the man-minutes per year required to manage the contents distribution of a client server system from 14,227.2 minutes to 1,144 minutes, namely reduces 92% of the time. The user satisfaction of the system was also found to be above 80% among six factors of the measurement designed by Bailey, et al. [1].

A robust web-based approach for broadcasting downward messages in a large-scaled company

Downward communication is a popular push-based scheme to forward messages from headquarters to front-line staff in a large-scaled company. With the maturing intranet and web technology, broadcasting algorithms, including pull-based and push-based broadcasting algorithms, it is feasible to send downward messages through web-based design by sending packets on a network. To avoid losing messages due to the traditional push-based method, companies adopt a pull-based algorithm to build up the broadcasting system. However, although the pull-based method can ensure that a message is received, it has a critical problem, the network is always congested. The push-based method can avoid congesting the network, but it needs a specific robust design to ensure that the message reaches its destination. Hence, adopting only a pull-based or a push-based broadcasting algorithm is no longer feasible especially not for a large-scaled company with complex network architecture. To ensure that every receiver will read downward messages thereby reducing the consumption of network bandwidth, this work proposes a robust web-based push- and pull-based broadcasting system for sending downward messages. This proposed system was successfully applied to a large-scaled company for a one-year period.

Solving two-dimensional Markov chain model for call centers

Purpose – The purpose of this paper is to develop a novel model of a call center that must treat calls with distinctly different service depending on whether they orginate from VIP or regular customers. VIP calls must be responded to immediately but regular calls can be routed to a retrial queue if the operators are busy. Design/methodology/approach – This study’s proposed model can easily reveal the optimal arrangement of operators while minimizing computational time and without losing any precision of the performance measure when dealing with a call center with more operators. Findings – Based on the results of the comparison between the exact method and the proposed approximation method, the approach shows that the larger the number of operators or inbound calls, the smaller the error between the two methods. Originality/value – This investigation presents a computational method and management cost function intended to identify the optimal number of operators for a call center. Because of computational...

Optimal services for content delivery based on business priority

In a content-delivery system, connections are viewed as resources for sending files. However, the growing business needs of large-scale networks require an effective content-delivery service for transferring files. Since connections are sparse resources, prioritizing connections is essential for efficiently delivering urgent files and regular files based on various business priorities. This study presents a loss function as a performance index for a content-delivery service. The proposed loss function was applied to a sample content-delivery system to derive the average number of regular files in the retry group, the probability of failure to transfer a regular file in the first attempt, and the probability of failure to transmit urgent files. Additionally, the loss was associated with the decreased number of reserve connections under regular hours and peak hours. The experimental results show that the proposed model finds the optimal number of reserve connections for sending high- and low-priority files, and a manager can increase the service rate to ensure that losses are tolerable when delivering urgent files. Finally, the relative probabilities of blocked urgent files and blocked regular files are used as an indicator of efficiency in reserving connections.

Proactive Peer-to-Peer Traffic Control When Delivering Large Amounts of Content within a Large-Scale Organization

The Peer-to-Peer (P2P) approaches utilize the passive means of delivering large amounts of content due to the ease of content delivery and small amount of effort required for file transmission and failure control by the file provider. However, P2P methods incur network congestion due to the large number of uncontrolled connections established by those retrieving content. Additionally, P2P methods potentially stop file providers from exchanging data with other devices because of congested outbound traffic. Therefore, existing P2P approaches are infeasible for large-scale organizations as a congested uncontrolled network is not ideal in a business environment. Related studies demonstrated that the active method for content can minimize outbound congestion for a provider but it needs the fault tolerance. This study presents a novel application called Enterprise Peer-to-Peer (EP2P), which integrates passive and active approaches. Using EP2P, the outbound traffic from a sender on an Intranet can be controlled efficiently, because the transmission between a provider and many receivers can be changed from passive to active on necessary. Therefore, we suggest organizations use EP2P for the delivery of content.

Measuring the cost of links of a disaster-avoided content-delivering service within a large-scaled company

A content-delivering service within a large-scaled company in Taiwan has been proposed to use 40 servers to meet user requirements on the previous study. The managers of the case company want to use resources as few as possible. From previous study [19--21], we suggest them using 19 servers to deliver large files. However, because we need not only servers but also links to deliver content from the source to all destinations, we cannot discuss servers merely. Therefore, we must discuss about the reliability and cost of links that in previous study it discussed few about this matter. Since the important packets must be delivered on time, and the regular packets are flexible. Therefore, we need a proper design to make the important packets deliver to the destinations without mistake. The regular packets also need to be delivered to destinations, but they can resent to destinations until the urgent files are delivered completely. Therefore, the reliability design of links must consider following utilization: the system is used to deliver every kind of data securely, but the important packets must be delivered without delay. Therefore, this work models the reliability and cost of links to find the proper resource allocation that can help manager delivering urgent files and regular files.

The effects of computer assisted instruction to train people with reading disabilities recognizing chinese characters

Chinese stem-deriving instruction has been proved to effectively help people with reading disabilities recognize Chinese characters. With the applications and development of information technology, cybernetic Chinese stem-deriving instruction can help more people with reading disabilities learn Chinese characters and peruse articles more effectively. In this study, we develop computer-assisted instruction method for Chinese stem-deriving instruction and compare three teaching strategies. In this work, we recruit three elementary students with reading disabilities as participants, and evaluate the effectiveness of instructing with a proposed teaching strategy.