Osamu Takizawa

Evaluation and improvement of the tempest fonts

Information leakage via electromagnetic emanation, usually known as Tempest, has been recognized as a threat and countermeasures have been proposed. In particular, Kuhn and Anderson developed a protective measure for Tempest called the Tempest fonts. Through experiments, we have investigated and evaluated the effectiveness of the Tempest fonts. Furthermore, we propose a new measure based on a similar approach to prevent successful Tempest attacks. While Kuhn and Anderson use Fourier transformation as a low-pass filter, our approach uses a Gaussian filter in addition to Fourier transformation. Our experimental results show that this approach is more effective.

Measurement of in vivo local shear modulus using MR elastography multiple-phase patchwork offsets

Magnetic resonance elastography (MRE) is a method that can visualize the propagating and standing shear waves in an object being measured. The quantitative value of a shear modulus can be calculated by estimating the local shear wavelength. Low-frequency mechanical motion must be used for soft, tissue-like objects because a propagating shear wave rapidly attenuates at a higher frequency. Moreover, a propagating shear wave is distorted by reflections from the boundaries of objects. However, the distortions are minimal around the wave front of the propagating shear wave. Therefore, we can avoid the effect of reflection on a region of interest (ROI) by adjusting the duration of mechanical vibrations. Thus, the ROI is often shorter than the propagating shear wavelength. In the MRE sequence, a motion-sensitizing gradient (MSG) is synchronized with mechanical cyclic motion. MRE images with multiple initial phase offsets can be generated with increasing delays between the MSG and mechanical vibrations. This paper proposes a method for measuring the local shear wavelength using MRE multiple initial phase patchwork offsets that can be used when the size of the object being measured is shorter than the local wavelength. To confirm the reliability of the proposed method, computer simulations, a simulated tissue study and in vitro and in vivo studies were performed.

Rescue Infrastructure for Global Information Collection

In the disaster situation, it is important to collect quickly global information on the disaster area and victims buried in the debris and waiting for rescue. In the DDT project (special project for earthquake disaster mitigation in urban areas), the research and development on rescue infrastructure for global information collection have been carried out. In the activity of the mission unit for infrastructure, ubiquitous handy terminal devices have been and technology for forming an ad-hoc wireless communication network have been developed as well as technology to integrate the collected information on the GIS system including communication protocol design. In this paper, the current R&D activities of the mission unit for infrastructure in the DDT project are overviewed, and some technologies developed so far are introduced

Method of hiding information in agglutinative language documents using adjustment to new line positions

Information hiding technology embeds information using the redundancy of information contained in cover data. Therefore, many information-hiding techniques for cover data with a lot of redundancy, such as images or sound signals, have been proposed. Most proposed information hiding techniques that set document to cover data tampered with layouts between spacing and words. In this paper, a new information hiding technique for agglutinative languages like Japanese or Korean that have no spaces between morphemes is proposed. By the proposed technique, digital documents are set to cover data and secret data is embedded by making the position of the new-line code inserted into document correspond to secret data. The technique can also be applied to plain text like an e-mail, which does not have layout information. Because the technique does not change the content of the cover data at all, the technique can be used not only as steganography aiming at performing secret communication but also as digital watermarking. Moreover, the technique has the feature whereby embedded data remains also in the printing output.

Hybrid radio frequency identification system for use in disaster relief as positioning source and emergency message boards

We developed a system that uses radio frequency identification (RFID) tags both as the source of location information and as data storage units to record messages or information in disaster situations. Our system uses hybrid RFID tags, which consist of a passive (non-battery) tag and an active (battery-driven) tag. The system has been evaluated in disaster prevention trainings by local communities and rescue teams.

On the Performance of a Hybrid Wireless Network for Emergency Communications in Disaster Areas

Fast deployment of an emergency wireless communication system is essential to provide communication services to survivors and rescue teams in the event of a disaster because the telecommunication infrastructure might be damaged. We present and discuss a hybrid system model of wireless data networks for emergency communications in disaster areas. Because wireless resources are limited, efficient resource management mechanisms are needed to enhance system performance and provide users with QoS. We created a novel resource management scheme for hybrid wireless networks that provides not only high quantity simultaneous connections but also the minimum required throughput. This scheme enables selected powerful end users to operate as temporary relay hosts (TRHs), enabling system resources to be utilized efficiently. The scheme combines network-controlled handover, resource allocation, and admission control and takes advantage of adaptive transmission rates and a multi-hop/relay communication mode. The results obtained by a computer simulation show that using our resource management scheme can reduce the connection blocking probability, i.e., increase the number of simultaneous connections.

Introduction of Task Force for Rescue System Infrastructure in Special Project for Earthquake Disaster Mitigation in Urban Areas

In this paper, we describe a task force for a rescue system infrastructure for earthquake disaster mitigation in urban areas, and as a final result, its widespread social foundation for a rescue system. The results of each research group are introduced

Development of a Networked Robotic System for Disaster Mitigation

In this paper, the research project named “networked robotic system for disaster mitigation” is introduced. The project aims to develop key technologies for multiple robots to be teleoperated through a wireless communication network, which includes a satellite communication link, for surveillance tasks at a disaster site. The robotic system consists of a large-scale outdoor robot and a group of smaller indoor robots. The large-scale robot will serve as a carrier for the smaller robots which are deployed inside a partly-collapsed building. A three-dimensional range sensor and an omnidirectional camera are used as tools to ease the teleoperation for the human operator. This paper presents the mission scenario and the development status of the proposed networked multi-robotic system. The results of the performance tests are also reported.

Earthquake intensity estimation and damage detection using remote sensing data for global rescue operations

In order to support global rescue operations, we propose a new earthquake damage detection method based on a combination of both the result estimated by using earthquake information (magnitude, location of source, detailed ground conditions, and distance attenuation equation), and change detection using multi-temporal SAR data. First, to find collapsed buildings and houses on the earths surface, we adopt a difference image calculated from multi-temporal SAR images observed before and after the earthquake. Next, to estimate seismic intensity and probability of destruction caused by the earthquake, we apply an earthquake engineering model. Finally, damaged area is calculated using a logical AND of difference image and the destruction probability. In order to show that we can obtain a damage detection map which corresponds with the actual damage of houses, we applied the method to simulations of the 2008 Sichuan earthquake in China.

Information acquisition using intelligent sensor nodes and an autonomous blimp

In case of disasters such as a big earthquake in the urban city, it is one of the most important problems to acquire information of the disaster environment, victimspsila position and status. Although, at present, rescue corps and dogs strive to find the victims everywhere in the disaster area, it takes too long time. To address this problem, a small sized wireless ubiquitous sensor node called ldquoRescue Communicatorrdquo is developed. Rescue Communicator can call to the missing victims possibly trapped under rubble and record their voices if any so as to efficiently find them immediately after the disaster. Installed indoors prior to the attack of a disaster or placed in the disaster-affected site after the attack, the devices under development are capable of forming an ad-hoc network throughout the environment around the site. This works in parallel at the disaster site (ubiquitously searching) and supports that rescue corps search for the victim, effectively. This paper will discuss about outdoor basic operation experiment of Rescue Communicators which cooperate with blimp.