Vol. 4, No. 1, Feb. 2008
Wen-Chi Hou, Yang Pan, Dunren Che
Vol. 4, No. 1, pp. 1-8, Feb. 2008
Keywords: Disk Striping, Multimedia System, Bandwidth
Show / Hide AbstractIn this paper, we discuss the use of fragmented bandwidth to improve the performance of staggered striping in a multimedia system. It is observed that potential disruptions can occur when nonconsecutive idle disks are used for displaying multimedia objects. We have identified useful retrieval patterns and shown that with proper selections of fragmented disks and a simple buffering scheme, disruptions can be easily eliminated.
Sang-Hun Eo, Yan Li, Ho-Seok Kim, Hae-Young Bae
Vol. 4, No. 1, pp. 9-16, Feb. 2008
Keywords: DBMS, Storage Management, Query Processing
Show / Hide AbstractThis paper describes the design and implementation of a two-tier DBMS for handling massive data and providing faster response time. In the present day, the main requirements of DBMS are figured out using two aspects. The first is handling large amounts of data. And the second is providing fast response time. But in fact, Traditional DBMS cannot fulfill both the requirements. The disk-oriented DBMS can handle massive data but the response time is relatively slower than the memory-resident DBMS. On the other hand, the memory-resident DBMS can provide fast response time but they have original restrictions of database size. In this paper, to meet the requirements of handling large volumes of data and providing fast response time, a two-tier DBMS is proposed. The cold-data which does not require fast response times are managed by disk storage manager, and the hot-data which require fast response time among the large volumes of data are handled by memory storage manager as snapshots. As a result, the proposed system performs significantly better than diskoriented DBMS with an added advantage to manage massive data at the same time.
Vol. 4, No. 1, pp. 17-26, Feb. 2008
Keywords: String Vector, K- Nearest Neighbor, Text Categorization
Show / Hide AbstractThis research proposes a new strategy where documents are encoded into string vectors and modified version of KNN to be adaptable to string vectors for text categorization. Traditionally, when KNN are used for pattern classification, raw data should be encoded into numerical vectors. This encoding may be difficult, depending on a given application area of pattern classification. For example, in text categorization, encoding full texts given as raw data into numerical vectors leads to two main problems: huge dimensionality and sparse distribution. In this research, we encode full texts into string vectors, and modify the supervised learning algorithms adaptable to string vectors for text categorization.
Maryann Dorn, Wen-Chi Hou, Dunren Che, Zhewei Jiang
Vol. 4, No. 1, pp. 27-32, Feb. 2008
Keywords: Data Mining, Association Rule Mining, Rule Evaluation, Chi-square Test
Show / Hide AbstractMinimum support and confidence have been used as criteria for generating association rules in all association rule mining algorithms. These criteria have their natural appeals, such as simplicity; few researchers have suspected the quality of generated rules. In this paper, we examine the rules from a more rigorous point of view by conducting statistical tests. Specifically, we use contingency tables and chi-square test to analyze the data. Experimental results show that one third of the association rules derived based on the support and confidence criteria are not significant, that is, the antecedent and consequent of the rules are not correlated. It indicates that minimum support and minimum confidence do not provide adequate discovery of meaningful associations. The chi-square test can be considered as an enhancement or an alternative solution.
Eun Man Choi, Kwang-Ik Seo
Vol. 4, No. 1, pp. 33-40, Feb. 2008
Keywords: software engineering, Software Testing, Traceability, UML-based Testing
Show / Hide AbstractTraceability has been held as an important factor in testing activities as well as modeldriven development. Vertical traceability affords us opportunities to improve manageability from models and test cases to a code in testing and debugging phase. This paper represents a vertical test method which connects a system test level and an integration test level in testing stage by using UML. An experiment how traceability works to effectively focus on error spots has been included by using concrete examples of tracing from models to the code.
Sunil Kumar, Mahasweta Sarkar, Supraja Gurajala, John D. Matyjas
Vol. 4, No. 1, pp. 41-52, Feb. 2008
Keywords: medium access control, MAC, Ad Hoc Networks, Multi Hop, QoS, Multimedia
Show / Hide AbstractIn this paper, we discuss a novel reservation-based, asynchronous MAC protocol called¡®Multi-rate Multi-hop MAC Protocol¡¯ (MMMP) for multi-hop ad hoc networks that provides QoS guarantees for multimedia traffic. MMMP achieves this by providing service differentiation for multirate real-time traffic (both constant and variable bit rate traffic) and guaranteeing a bounded end-to-end delay for the same while still catering to the throughput requirements of non real time traffic. In addition, it administers bandwidth preservation via a feature called ¡®Smart Drop¡¯ and implements efficient bandwidth usage through a mechanism called ¡®Release Bandwidth¡¯. Simulation results on the QualNet simulator indicate that MMMP outperforms IEEE 802.11 on all performance metrics and can efficiently handle a large range of traffic intensity. It also outperforms other similar state-of-the-art MAC protocols.