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High-speed power line communication (PLC) is useful technology to easily build the communication networks, because construction of new infrastructure is not necessary. In Europe and America, PLC has been used for broadband networks since the beginning of 21th century. In Japan, high-speed PLC was deregulated only indoor usage in 2006. Afterward it has been widely used for home area network, LAN in hotels and school buildings and so on. And recently, PLC is greatly concerned as communication technology for smart grid network. In this paper, the author surveys the high-speed PLC technology and its current status.

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The high speed powerline communication (PLC) technology is useful for a variety of applications especially for Smart Grid. Although the standardization of this technology has been desired for a long time, recently IEEE P1901 and ITU-T SG15 made significant progress and both of the Standards are expected to be completed by the end of 2010. The frame work of the coexistence mechanism among the different types of PLC technologies is also going to be resolved with the collaborative work between IEEE and ITU-T. In this paper, the authors introduce the summary of the International Standardizations of this technology, and also the future prospects of the Standards.

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A distribution apparatus might exist on the communication route and it deteriorates the communication performance, in the high speed power line communications. We report the result of study on the signal bypass unit, which improves the line characteristic and advances the communication performance, by making the communication signal bypass the distribution apparatus effectively.

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The use of PLC (Power Line Communication) has been spreading in Japan. However, signal transition characteristics between different pairs of lines in single-phase three-wire system are not clear. In this paper, the signal transition characteristics of out-phase lines of indoor main power lines are experimentally investigated and an estimation method of signal transition level using distributed constant circuit is proposed.

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The elements of distribution lines were individually modeled for moment methods simulation. To confirm propriety of modeling, simulation results of magnetic field emission were compared with measured one from the distribution lines under test. Both cumulative values in emission spectrum are good agreed within 5 dB differences and the propriety of modeling was confirmed. We have investigated dominant parts of emission by simulation using above modeling. And it was clarified that the emission from LV lines is dominant except for near the pole and the drop cable.

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In this paper, we paid to attention for a distribution board actually used at house, and evaluated the transmission loss characteristic of the power line transmission model with the distribution board, and verified whether it is possible to analyze the transmission loss characteristic by using four terminal pair network theory, which has circuit constant as chain matrix of distributed constant on transmission line. As the result, in the condition without a branch line, it is confirmed that the calculation value agrees well with measurement one on both in-phase and out-of phase transmissions. Moreover, in the condition connecting the branch line at the distribution board, calculation value agrees well with measurement one in transmission loss and resonance frequency by considering the conductance of the insulating dielectrics of a power line. Therefore, it is verified that the validity by using the four terminal pair network theory for analysis of power line through the distribution board.

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In this paper, we measured the immunity characteristics to the conducted interference wave, from the aspect of PHY rate (physical layer data rate) of PLC (Power Line Communication) system, and compared with simulation results by MATLAB/ Simulink. When the interference signal is impressed to the OFDM (Orthogonal Frequency Division Multiplexing) signal, the PHY rate decrease rapidly below C/I (Carrier / Interference) = 25dB and become nearly zero around C/I = -35dB, and so it turns out that the PLC System with OFDM signal has a good narrowband interference immunity characteristic. In addition, it is revealed that the PHY rate of PLC modem can be calculated by MATLAB/Simulink even when the narrowband interference signal is impressed through the power line. Furthermore, we examined the improving effect of the notch band for the immunity characteristics to the conducted interference wave. As a result, it is revealed that the PHY rate normalized by the maximum value increases by 15∼25% by inserting the notch when impressing the interference signal in the notch band and C/I is improved by 10∼15dB by inserting the notch.

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In this paper, we measured the interference immunity characteristics of high-speed PLC system using Wavelet-OFDM when the narrowband conducted interference wave signal was injected. As the results, it was clear that (1) measured PHY rate at the all frequency band hardly decreased in C/I (Carrier to Interference ratio) of above 20dB, but began to decrease rapidly in C/I of below 0dB when the interference signal was injected in the frequency band of high-speed PLC signal, (2) when C/I became from 0dB to -20dB, the measured PHY rate at the frequency existing the notch band were improved around 10Mbps than that at the frequency not existing the notch band, (3) when the narrowband interference wave was injected outside of frequency band of high-speed PLC signal, the measured PHY rate did not decrease than that in each notch band. Therefore, it was revealed that high-speed PLC system using Wavelet-OFDM had good interference immunity characteristics.

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Power-line communication (PLC) based local area network (LAN) in cargo ships is one of the promising applications of the PLC technology. In this paper, the signal attenuation characteristic when transmitting with the differential-mode (DIF) and the common-mode (COM) has been modeled respectively to design the PLC network in a cargo ship. The characteristic has been analyzed from the measured transfer function of 440V power-line channels for reefer containers in two typical ships. The measured transfer function was averaged from 2M to 30MHz (or until the measurement limit frequency) and approximated by the number of branches and the length of a signal propagating route. The mean accuracy of the obtained approximation equations was ±4dB. The area where the signal attenuation of COM transmission is less than that of DIF transmission has been studied from the equations.

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This paper reports on the achievement of high-power 4H-SiC Zener diodes which have a high-doped pn junction with a large active area of 4 mm×4 mm. The temperature coefficient of the breakdown voltage is as small as 5.7×10^-5 1/K (positive) in the temperature range 20-300°C. The Zener voltage of the fabricated Zener diodes decreased from 41 to 17 V with an increase in the doping concentration. In addition, power capabilities during rectangular pulsed power (t_w = 1 ms) are 6.3 kW (40 kW/cm²) at 20°C and 6.0 kW (38 kW/cm²) at 300°C. The repeatable current test for 1 hour with triangular pulse, which corresponds to the surge current under the inverter operation, has been achieved without device failure.

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This paper proposes four different methods for preventing cold boot attacks. These attacks exploit DRAM remanence to acquire private information stored in a memory. DRAM modules can keep stored values for many seconds without a power supply, in particular at low temperature. To address cold boot attacks, circuit-shorting method, SRAM preservation method, and cell selection method are proposed. The integrated method of these methods is also proposed because these methods are independent and can be achieved together. These proposed methods are evaluated by using actual testbeds.

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In wireless communications, determining the physical location of nodes (localization) is very important for many network services and protocols. This paper evaluates the static performance of wireless localization algorithm exploiting Self-Organizing Maps (SOM) to deal with this issue. Our proposed algorithm utilizes only connectivity information and information from some heard anchors in the network to determine the location of nodes. By introducing an efficient two-hop utilization scheme and the multi-hop anchor update, the algorithm has maximized the correlation between neighboring nodes and the global topology in distributed implementation of SOM. From our intensive simulations on various static network deployment scenarios, the results show that the proposed scheme achieves very good localization accuracy. It also reduces the SOM learning steps to around 15 to 30 steps to overcome the huge computational problem of the classical SOM.

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This paper discusses the streaming of high rate media such as video or audio information over ad hoc networks in disaster situations or for temporary events when it is difficult to use fixed infrastructure. The conventional simple flooding is not applicable for this application because it generates a large number of redundant rebroadcast and heavy traffic load to the network. To restrain redundant rebroadcast messages, several methods have been proposed. But since those studies do not take into account the actual load condition at each node that will affect network efficiency, they cannot achieve both ensuring the high message reachability and reducing redundant rebroadcast. In this paper, we propose two novel load-aware flooding methods using the MAC transmission queue information at each node to make the decision about whether rebroadcast messages should be sent or not. Through network simulations, we evaluate and show the effectiveness of our proposals. The result shows that our proposals achieve both ensuring high message reachability and restraint of redundant rebroadcast comparing with existing methods.

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In order to establish a new diagnostic method for central olfactory disorders and to identify objective indicators, we measured and analyzed brain activities in the parahippocampal gyrus and uncus, region of responsibility for central olfactory disorders. The relationship between olfactory stimulation and brain response at region of responsibility can be examined in terms of fitted responses (FR). FR in these regions may be individual indicators of changes in brain olfactory responses. In the present study, in order to non-invasively and objectively measure olfactory responses, an odor oddball task was conducted on four healthy volunteers using functional magnetic resonance imaging (fMRI) and a odorant stimulator with blast-method. The results showed favorable FR and activation in the parahippocampal gyrus or uncus in all subjects. In some subjects, both the parahippocampal gyrus and uncus were activated. Furthermore, activation was also confirmed in the cingulate gyrus, middle frontal gyrus, precentral gyrus, postcentral gyrus, superior temporal gyrus and insula. The hippocampus and uncus are known to be involved in the olfactory disorders associated with early-stage Alzheimer's disease and other olfactory disorders. In the future, it will be necessary to further develop the present measurement and analysis method to clarify the relationship between central olfactory disorders and brain activities and establish objective indicators that are useful for diagnosis.

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Engineers with system architecture design and project management abilities are required in the field of embedded system development. In university, however, educations are mainly focused on computer science and programming; systems engineering and project management education have been disregard. We implemented educational curriculum of systems engineering and project management in embedded system for graduate program. In this paper the course design, execution and evaluation are described.

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In this paper, we propose a reliable method for view-based navigation of mobile robots fully improved in positional accuracy by using feature-points extracted by SURF, and it is verified from the navigation experiments of them. View-based navigations that have used block matching method are not enough in positional accuracy for robots to avoid obstacles and pass narrow doorways. By applying SURF that is stable to illumination and scale changes in an image to the method for view-based navigation, the navigation for robots becomes more robust to variable indoor conditions. In experiments conducted in an indoor corridor with a robot for comparing the proposed method to conventional one, the positional precision was obtained in centimeter-order of within 10.0[cm]. In this view, it suggests that the proposed method is applied to the view-based navigation for robots in such narrow areas as obstacle avoidance and corridors.

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Control charts are widely applied to monitoring quality variation from stable status to instable status in many manufacturing lines. Large-scale integrated circuit(LSI) manufacturing requires to monitor thin film thicknesses, circuit pattern dimensions, particle count on a wafer and so on. This paper proposes a new monitoring method for particles on a wafer. If particles induce random location based on Poison distribution, the c-chart is applicable. However, actual particle generation is not dependent of Poison distribution and then the c-chart indicates many false alarms. The proposed method predicts particle-limited yield to apply the p-chart to monitoring particle data. The method uses data outputted by a particle inspection tool such as a particle location and a scattered light intensity with respect to each particle. Experiments show that the method reduces false alarms.

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This paper presents a linear luminance-chrominance gain equalizer for correcting the linear chrominance gain distortion in the color TV transmission system. The proposed gain equalizer was implemented based on Bernstein polynomials. As it is known that the Bernstein filter has flexible parameters to adjust the circuit performance for the best results. In addition, the modulated 20T sine-squared pulse test signal is generated for testing the performance of the proposed gain equalizer, which can be measured all three types of the linear chrominance distortions. As the results, the proposed gain equalizer is also proved to be efficient in equalizing both the low gain and the high gain chrominance distortions without degrading its phase characteristics.

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Many people are involved in accidents every year at railroad crossings, but there is no suitable sensor for detecting pedestrians. We are therefore developing a ubiquitous stereo vision based system for ensuring safety at railroad crossings. In this system, stereo cameras are installed at the corners and are pointed toward the center of the railroad crossing to monitor the passage of people. The system determines automatically and in real-time whether anyone or anything is inside the railroad crossing, and whether anyone remains in the crossing. The system can be configured to automatically switch over to a surveillance monitor or automatically connect to an emergency brake system in the event of trouble. We have developed an original stereovision device and installed the remote controlled experimental system applied human detection algorithm in the commercial railroad crossing. Then we store and analyze image data and tracking data throughout two years for standardization of system requirement specification.

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In this paper, we propose a method for compressing a still image using vector quantization (VQ). Local fractal dimension (LFD) is computed to divided an image into variable block size. The LFD shows the complexity of local regions of an image, so that a region of an image that shows higher LFD values than those of other regions is partitioned into small blocks of pixels, while a region of an image that shows lower LFD values than those of other regions is partitioned into large blocks. Furthermore, we developed a division and merging algorithm to decrease the number of blocks to encode. This results in improvement of compression rate. We construct code books for respective blocks sizes. To encode an image, a block of pixels is transformed by discrete cosine transform (DCT) and the closest vector is chosen from the code book (CB). In decoding, the code vector corresponding to the index is selected from the CB and then the code vector is transformed by inverse DCT to reconstruct a block of pixels. Computational experiments were carried out to show the effectiveness of the proposed method. Performance of the proposed method is slightly better than that of JPEG. In the case of learning images to construct a CB being different from test images, the compression rate is comparable to compression rates of methods proposed so far, while image quality evaluated by NPIQM (normalized perceptual image quality measure) is almost the highest step. The results show that the proposed method is effective for still image compression.

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In this paper, we propose an arrangement and detection method of an invisible calibration pattern based on characteristics of human visual perception. A calibration pattern is arranged around contents where invisible data is embedded, as some feature points between an original image and the scanned image for normalization of the scanned image. However, it is clear that conventional methods interfere with page layout and artwork of contents. Moreover, conventional visible patterns show a third person the position of embedded data. Therefore, visible calibration patterns are not suitable for security service. The most important part of human visual perception in the proposed method is the spectral luminous efficiency characteristic and the chromatic spatial frequency characteristic. In addition, a back ground color in surrounding of contents is not restricted to uniform color by using the proposed calibration pattern. It is suggest that the proposed method protect page layout and artwork.

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Japan's social security system is facing a crisis by short-sighted policies to balance of the accounts in a financial crisis. However, such a balance of accounts does not necessarily bring remedy of financial difficulties. If it is possible to reduce the social security payments because the weak become independent, it is considered that short-sighted reforms cause a further financial crisis.
This study explores how welfare and tax burden influence fiscal balance using multi-agent simulations. The results of simulation show that fiscal balance is improved by high-welfare than a cut in fiscal expenditures, and that welfare reducing is impossible unless the three relations of social configuration (market, obligatory, and communal relations) function in balance with each other.

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In these days, telecom operators in the world have been constructing Next Generation Network (NGN). NGN can provide QoS and security guaranteed communication to its users. However, the protection of communication is limited inside NGN. Therefore, when the interconnection between NGN and the Internet will be widely used in near future, it will become an important problem to solve how it protects the communications crossing over NGN and the Internet.
This paper proposes a secure communication provider service that protects the confidentiality and integrity of communications crossing over NGN and the Internet by setting up and controlling the IPsec session in cooperation with NGN's call session control function (CSCF). In this service, the secure session control provider (sSCP) server and CSCF authenticate its user as Trusted Third Party on behalf of service providers. In addition, this service provides the ability of fast session establishment because sSCP distributes a security association for IPsec session between the user and service provider via the SIP session protected by NGN.

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A convenient InGaAs charge integrating amplifier was fabricated working at the temperature of -60°C without using liquid nitrogen. The temperature of -60°C was easily achieved using a commercial cooler. The minimum detectable power of 10^-13W (NEP 2×10^-13W/Hz^1/2) was accomplished. The spectrum of singlet oxygen from Rose-Bengal was measured successfully.

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3-dimensional sound field with high accuracy is an important topic for MR (Mixed Reality) to create the high immersion sense. HRTF (Head-Related Transfer Function) can achieve 3-dimensional sound field, whereas the measurement of the HRTF for each person is difficult because the measurement of the HRTF requires the expensive equipment and environment. In this paper, we propose a method to design HRTF by piecing several HRTFs selected from a large database of HRTFs. As a result of evaluation experiments, we confirmed that the proposed method can design the useful HRTF.

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