Yusuke Yokota

A Cooperative Power-Saving Technique Using DVS and DMS Based on Load Prediction in Sensor Networks

In wireless sensor networks (WSN), energy saving is the main issue of research, and many energy saving techniques have been proposed. Dynamic Voltage Scaling (DVS) and Dynamic Modulation Scaling (DMS) are techniques reduce energy consumption by using the idle time of the sensor node. When we use both techniques at the same time, an appropriate mechanism of cooperation is required because of the limitation of available idle time of the sensor node. Therefore, we propose a cooperative power. saving technique that applies DVS and DMS to sensor nodes for minimizing energy consumption. It uses a prediction mechanism that estimates the load of the processor and the radio communication device based on the log data to realize proper cooperation. We observed that the adaptation of the proposed technique is able to achieve the energy reduction up to 40 percent compared to without any energy saving techniques.

Graining and filling understanding gaps for novice programmers

Present programming education methods bring about many big gaps in understanding of many novice programmers. Novices suffering from big gaps in understanding would lose confidence to continue to learn programming. We introduce a method named AtoP to grain the big gaps into small gaps so that a novice can overcome the gaps. The method aims to associate programming with knowledge in many areas through interactive supervision and self-efficacy promotion.

Refining programming education course with absolute measures

This paper proposes a method to refine education contents with absolute measures. The measure is constructed based on the collective intelligence approach. The method values the motivation and the understanding of students. Operations, which are units of service in programming education courses are selected automatically to reduce refinement costs.

A Technique for Construction of Overlay Networks for MANETs with Consideration of Physical Network Topologies

Recent years, the mobile ad hoc networks (MANETs) research community has been very active. Thus, it is of growing importance to build distributed network applications on top of MANETs. DHT is known as a popular technique to build efficient distributed applications in the Internet. However, in MANETs, DHT needs to consider network traffics, moving of nodes and energy efficiency more carefully than the Internet. We propose a technique for construction of overlay networks for MANETs in consideration for topologies of physical networks. Our technique realizes the pure P2P network that does not require special nodes like cluster heads or super peers. It gives a node ID to each node in a network using information from physically neighbor nodes so that the node has a node ID value close to that of neighbor nodes. Thus the neighbor nodes in the physical network will be also close in the logical network. When a node moves, a node ID will be reallocated to meet the above requirement. We evaluate the performance of the proposed technique by the simulations.