Gwang S. Jung

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Recall and precision are often used to evaluate the effectiveness of information retrieval systems. They are easy to define if there is a single query and if the retrieval result generated for the query is a linear ordering. However, when the retrieval results are weakly ordered, in the sense that several documents have an identical retrieval status value(More)
Two problems that arise when recall and precision are used to evaluate information retrieval systems are due to the weak ordering of the documents generated by the system and evaluation with multiple queries. Although several alternative stopping criteria are available, our emphasis in this paper is on defining precision when recall is used as the stopping(More)
Retrieval system evaluation plays an important role in judging the efficiency and effectiveness of the retrieval process. Several different evaluation criteria, deemed most critical to user population, were pointed out ir(SALTON83, CLEVERDON70]; namely, recall, precision, effort, time, form of presentation and coverage. Among them, recall and precision have(More)
Recently, there is an increasing demand on delivering video data over the Internet. In this paper, we propose a novel method of delivering video stream to a client by utilizing multithreaded parallel connections from the client to multiple geographically distributed servers. The proposed approach has been developed to deliver high quality best-effort MPEG-1(More)
Ahstmct: In multimedia database applications, a, major class of users’ requests require retrieving those images in the database that are spatially similar to the query image. To process such queries, a spatial similarity function is required. A spatial similarity function assesses the degree to which the spatial relationships among the domain objects in a(More)
Multimedia data is characterized by large objects that require high-bandwidth. This paper presents a technique that enables efficient and dependable data storage and delivery of large multimedia objects in the World Wide Web environment. The proposed approach strips data into blocks that are distributed over multiple Web servers. Data distribution is(More)