Yung-Chun Wan

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The explosive growth in wireless networks over the last few years resembles the rapid growth of the Internet within the last decade. During the beginning of the commercialization of the Internet, organizations and individuals connected without concern for the security of their system or network. Over time, it became apparent that some form of security was(More)
The “How much information?” study produced by the school of information management and systems at the University of California at Berkeley [10], estimates that about 5 exabytes of new information was produced in 2002. It estimates that the amount of stored information doubled in the period between 1999 and 2002. It is believed that more data will be created(More)
In this paper we study the following problem. There are n pages which clients can request at any time. The arrival times of requests for pages are known in advance. Several requests for the same page may arrive at different times. There is a server that needs to compute a good broadcast schedule. Outputting a page satisfies all outstanding requests for the(More)
Our work is motivated by the problem of managing data on storage devices, typically a set of disks. Such high demand storage servers are used as web servers or multimedia servers, for handling high demand for data. As the system is running, it needs to dynamically respond to changes in demand for different data items. There are known algorithms for mapping(More)
We consider the problem of moving a large amount of data from several source hosts to a destination host over a wide-area network, i.e., a large-scale data collection problem. This problem is important since improvements in data collection times are crucial to performance of many applications, such as wide-area uploads, high-performance computing, and data(More)
In this paper we consider the problem of collecting a large amount of data from several different hosts to a single destination in a wide-area network. Often, due to congestion conditions, the paths chosen by the network may have poor throughput. By choosing an alternate route at the application level, we may be able to obtain substantially faster(More)