Masaya Nakayama

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In this paper, we show detailed analysis and performance evaluation of the Dynamic Hybrid GRACE Hash Join Method (DHGH Method) when the tuple distribution in buckets is unbalanced. The conventional Hash Join Methods specify the tuple distribution in buckets statically. However it may differ from estimation since join operations are applied with selection(More)
1 Introduction In this paper we propose a new hash-partitioned join method using a dynamic de&aging strategy for large scale databases. The traditional hash-partitioned join methods such as the Hybrid Hash Join Method assume that the size of each bucket can be controlled by selecting a split function, and the characteristics of the buckets are statically(More)
The Live E! project is an open research consortium among industry and academia to explore the platform to share the digital information related with the earth and our living environment. We have getting a lot of low cost sensor nodes with Internet connectivity. The deployment of broad-band and ubiquitous networks will enable autonomous and global digital(More)
The Live E! project is an open research consortium among industry and academia to explore the platform to share the digital information related with the earth and our living environment. We have getting a lot of low cost sensor nodes with Internet connectivity. The deployment of broadband and ubiquitous networks will enable autonomous and global digital(More)
We have developed a system that streams and archives live sound from remote areas across Japan via an unmanned automatic camera. The system was used to carry out pilot bird censuses in woodland; this allowed us to examine the use of live sound transmission and the role of social media as a mediator in remote scientific monitoring. The system has been(More)
ABSIRACT This paper proposes the multldlmenslonal cluster lng technique called GKD-tree method which IS fully adaptive to both of tuple and query dlstrlbutlons The method 1s bdsed on the theoretical analysis of the performance of multldlmensional clustermg Its algorithm and perIormance are described It IS shown that GKD tree method can largely reduce the(More)
—Wireless mesh networks suffer from intermittent connectivity, and thus hop-by-hop reliability and parallel message propagation, which DTN researches have explored, can be applied to allow scalable message propagation over such challenged network environments. We implemented those communication schemes onto UTMesh – 50-node scale wireless mesh network(More)
This paper aims at developing a honeypot system for web applications. The key idea is employing migration techniques to create a virtual machine as a honey web server, and making the honeypot to equip the same memory and block content of the real systems. Recently, web applications have been the target of numerous cyber attacks. In order to catch up new(More)