Tomotaka Kimura

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A real-time plasma shape visualization system has been developed for plasma control in the JT-60 tokamak. Fast digital signal processors (DSPs) having inter-processor communication ports are applied to parallel processing in this system. The optimum number of the DSPs was estimated according to the degree of the parallelism and allowable delay in the(More)
We propose a probabilistic store-carry-forward message delivery scheme based on node density estimation. In our scheme, when a node with a message copy encounters another node, the former forwards its copy to the latter with a certain probability. The forwarding probability is determined depending on a node density at the contact location where two nodes(More)
This paper proposes an adaptive virtual machine (VM) assignment scheme for multi-tenant data center networks. In multi-tenant data centers, tenants submit their resource requirements and the data centers provide VMs which are assigned to physical servers. These VMs communicate with each other to execute distributed processing. The amount of traffic(More)
Machine learning techniques have been achieving significant performance improvements in various kinds of tasks, and they are getting applied in many research fields. While we benefit from such techniques in many ways, they can be a serious security threat to the Internet if malicious attackers become able to utilize them to detect software vulnerabilities.(More)
One of the most important technical problems in store-carry-forward routing is to reduce the number of message copies in networks without increasing the message delivery delay. In order to solve this problem, we focus on utility-based routing schemes, where for a message, utility of a node indicates its proximity to the destination node of the message.(More)
In recent years, access-points have been densely placed at public spaces. Users can each select an access-point from among such access-points so as to enhance communication quality. Access-point selection methods have thus become an important technical issue. This paper proposes a new access-point selection method using Markov approximation, which adapt to(More)