Kazuhiro Ohtsuki

Analytic method for real-time traffic problems by using Contents Oriented Communications in VANET

Today, ITS (intelligent transport systems) is paid attention by people all over the world. ITS is the system that solves the road traffic problems by using communications technology of vehicles. IVC ( inter vehicle communications ) is the communications technology that vehicles exchange the information by using wireless LAN without any base stations. VANET ( vehicular ad-hoc network ) have been expected to provide new applications for passengers of vehicles, by enabling vehicles to communicate with each other via IVC as well as with roadside base stations via RVC ( roadside-to-vehicle communications ). We propose the COC ( contents oriented communications ) system on VANET via IVC. With COC, each vehicle collects original information that each vehicle has by communicating each other, and creates contents which may be useful for drivers, by analyzing original information. COC deliver the analyzed contents to other vehicles. The simulation results show that COC provide timely information of vehicular accidents and congestion to drivers.

Performance study of congestion control for high-speed backbone networks

Abstract We investigate the performance of a congestion control scheme for an interconnected network where several local area networks (LAN) are connected to a high-speed backbone network via bridges. In such a network, traffic congestion may occur due to the difference of transmission speed and/or workload between the high-speed backbone and the lower speed LANs. To release congestion and to obtain high throughput, we propose a congestion control scheme and evaluate the performance via simulation. In our scheme, each bridge always informs the other bridges of the number of available spaces in its buffer. The scheme gives the highest priority in transmission to the packets of the destination bridge which has the largest available buffer spaces. Simulation results show that the scheme significantly reduces the packet loss and provides high throughput in the backbone network. Furthermore, the scheme guarantees fast packet delivery between the uncongested bridges. However, the packets destined for the congested bridge stay in the buffer for a long time due to low transmission priority and shut out the other packets destined for the uncongested bridges. To avoid this, we improve the scheme by introducing a selective packet dropping function. The enhanced scheme restricts the maximum number of the packets which have the same destination. Not only has the enhanced scheme the advantage of the previous one, but it also guarantees the delivery of a packet of which the destination is not congested.

A Novel Urgent Communications Technologies for Sharing Evacuation Support Information in Panic-Type Disasters

Vast number of victims have damaged and died due to a lot of large-scale disasters (earthquake, fire, and terrorism, etc.) up to the present time. In disasters that most victims become panic, two matters are necessary to evacuate efficiently. The first is to estimate the location of the disaster occurrence. The second is to construct the evacuation support system that searches a safe and efficient evacuation route. In this paper, we propose Emergency Rescue Urgent Communication - Evacuation Support System (EUC-ESS) based on Mobile Ad-hoc NETworks (MANETs) composed of a lot of mobile terminals. By computer simulation, we show that this system would work to support the disaster victims regardless of situations (indoor, urban, basement, etc.)

Disaster Detection by Statistics and SVM for Emergency Rescue Evacuation Support System

The authors have proposed the Emergency Rescue Evacuation Support System (ERESS) for reducing human damage at disasters. The ERESS primarily intended to reduce the number of victims in panic-type disasters (e. g., fire, terrorism) and works under mobile ad-hoc networks (MANET). This system uses ERESS Mobile Terminals (EMTs) like smart phones and tablets. EMTs have an advanced disaster detection algorithm and sensors. They get data from sensors such as acceleration, angular velocity, and terrestrial magnetism. EMTs classify behavior of EMTs holders like walking and running, and detect disasters from escape actions. In this paper, the authors propose a new effective disasters detection method using statistics and a support vector machine (SVM). In this method, we introduce weight coefficient for each EMT holder according to his behavior statistics. Disasters simulation experimental results show the effectiveness of the proposed method.

Development of Emergency Rescue Evacuation Support System (ERESS) in Panic-Type Disasters: Disaster Detection by Positioning Area of Terminals

Previously, the authors have proposed the Emergency Evacuation Support System (ERESS) for reducing disaster damage. The ERESS runs under Mobile Ad-hoc Networks (MANET) and primarily aims to reduce the number of victims in panic-type disasters. This system uses ERESS Mobile Terminals (EMT) which are mobile terminals assuming smartphones and tablets. EMT is provided with an advanced disaster detection algorithm and acquires sensor information such as acceleration, direction difference and walking steps. However, disaster detection of conventional ERESS is needed the information of all members existing on the same floor. In this paper, we propose a new disaster detection method using the positioning area information. Location information of the terminal holders are obtained by Radio Frequency Identification (RFID). In this method, we separate a number of areas in the floor and detect a disaster by the information of evacuees in the presence of each area. We show the effectiveness of the proposed method by panic-type experiments.

A high-speed packet switch architecture with a multichannel bandwidth allocation

A novel packet switch architecture is proposed based on a channel grouped virtual circuit (CG-VC) scheme for high-speed communication networks. The case is considered in which there are several parallel channels between two switching nodes. The CG-VC scheme allows a packet to select an available channel in such a way as to avoid congested channels using a simple, hardware-based, self-routing mechanism. As a result, the architecture provides efficient channel use and low switching delay. The performance of the proposed switch is evaluated by simulation. The results show the proposed switch significantly improves channel utilization and switching delay compared with conventional single-channel allocation transmission policies.<<ETX>>

A New State Judgment Algorithm for Emergency Rescue Evacuation Support System (ERESS) in Panic-Type Disasters

Previously, Emergency Rescue Evacuation Support System (ERESS) has been proposed to reduce the number of victim in panic-type disaster. The ERESS operates under the Mobile Ad-hoc NETworks (MANET) environment and make it possible for ERESS users to exchange their physical activity information with each other. This system consists of new mobile terminals (handset size) with advanced disaster recognition algorithm and acquires sensor information such as acceleration, direction difference and walking steps. However, the former ERESS can judge only the big action like stopping, walking, running, and falling. In this paper, we newly introduce a myoelectric sensor into ERESS and propose new state judging algorithm.

A Language Learning System Utilizing RFID Technology for Total Physical Response Activities

In this paper, we present a method of integrating a CALL system with RFID tags in a classroom in order to provide the basic support for listening activities based on the concept of Total Physical Response (TPR) Approach. We designed and developed a prototype system with the function of providing corrective feedback. The prototype system has the following three features: (1) Real objects are used as the options for responding to audio questions. (2) A considerable amount of attribute information is used to increase the variation in the questions. (3) The system has a function of providing error messages and additional questions, depending on the degree of a learners mistakes. Results from the experiment suggest that integrating real objects into the learning system by using RFID tags has a potential impact on the language learners.

A learning model of computer science education for liberal arts students

With the development of information technology, the goals of computer science education for liberal arts in Japan have been extended, that is, not only to help them develop their computer operation skills and acquire their basic knowledge of the mechanism but also to help students develop their scientific thinking skills and understand the roles of information technologies. Students in noncomputer engineering major have pieces of knowledge on applications such as the products made with information technologies. They would also acquire the knowledge of the fundamental mechanism of computer and communication systems, by taking advantage of lectures. Therefore, it is important to organize the structure of their scientific knowledge by connecting those kinds of knowledge. This paper shows how we should organize various kinds of knowledge, and propose a learning style for this purpose. In addition to that, we show that a mailing list contributes to construct knowledge as a tool for cooperative learning.

Detection and position identification of disaster by using area information for emergency rescue evacuation support system

A number of people are killed or injured due to sudden disaster such as fire, terrorism or earthquake recently all over the world. The majority of the cause of death in these disasters is an escape delay. So the most effective method to reduce victims at the time of the disaster is to offer evacuation support information to the victim. To solve this problem, we are developing ERESS (Emergency Rescue Evacuation Support System) as a system that provides evacuation support in real time. In this paper, we propose a disaster detection and identification of disaster position using area information.