Browsing by Author "Huang, Jen-He"

Now showing 1 - 2 of 2

Exploiting replication on dependent data allocation for ordered queries over multiple broadcast channels
(2010-10-01)
Huang, Jiun-Long
;
Huang, Jen-He
;
資訊工程學系
;
Department of Computer Science
Data broadcasting has been recognized as an important means for information dissemination in mobile computing environments. In some mobile applications, the data items broadcast are dependent upon one another. However, most prior studies on broadcasting dependent data do not employ replication in broadcast program generation. In view of this, we explore in this paper the problem of broadcasting dependent data in multiple broadcast channels, and explicitly investigate the effect of data replication. After analyzing the model of dependent data broadcasting, we derive several theoretical properties to formulate the average access time of broadcast programs. In light of the theoretical results, we develop an algorithm to exploit replication on broadcast program generation. Our experimental results show that the proposed algorithm is able to generate broadcast programs of very high quality. In addition, the results also show that broadcast programs with replication is more robust than those without replication in error-prone environments.
On processing continuous frequent K-N-match queries for dynamic data over networked data sources
(2012-06-01)
Chiu, Shih-Chuan
;
Huang, Jiun-Long
;
Huang, Jen-He
;
資訊工程學系
;
Department of Computer Science
Similarity search is one of the critical issues in many applications. When using all attributes of objects to determine their similarity, most prior similarity search algorithms are easily influenced by a few attributes with high dissimilarity. The is proposed to overcome the above problem. However, the prior algorithm to process frequent --match queries is designed for static data, whose attributes are fixed, and is not suitable for dynamic data. Thus, we propose in this paper two schemes to process continuous frequent --match queries over dynamic data. First, the concept of is proposed and four formulae are devised to compute safe regions. Then, scheme CFKNMatchAD-C is developed to speed up the process of continuous frequent --match queries by utilizing safe regions to avoid unnecessary query re-evaluations. To reduce the amount of data transmitted by networked data sources, scheme CFKNMatchAD-C also uses safe regions to eliminate transmissions of unnecessary data updates which will not affect the results of queries. Moreover, for large-scale environments, we further propose scheme CFKNMatchAD-D by extending scheme CFKMatchAD-C to employ multiple servers to process continuous frequent --match queries. Experimental results show that scheme CFKNMatchAD-C and scheme CFKNMatchAD-D outperform the prior algorithm in terms of average response time and the amount of produced network traffic.