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Unilateral spatial neglect is a higher brain dysfunction and neglect of the hemisphere of visibility. Prism adaptation is effective for the rehabilitation of unilateral spatial neglect. Then we proposed a virtual reality environment based rehabilitation support system for unilateral spatial neglect is proposed. In this system, a USN subject must point at the targets as rehabilitation practice in virtual environment. However, when person who is not used to virtual environment points at a target, a precision of pointing the target is low. The experimental results show that the comparison the precision between two methods to point the target in the virtual environment for prism adaptation.

Robotic assistance enables a surgeon to perform dexterous and precise manipulations. However, conducting robot assisted neurosurgery within the deep and narrow spaces of the brain presents the risk of unexpected collisions between the shafts of robotic instruments and their surroundings out of the microscopic view. Thus, we propose the provision of feedback using a truncated cone shaped virtual fixture generated by marking the edges of the top and bottom plane of a workspace in the deep and narrow spaces within the brain with the slave manipulator. The experimental results show that the virtual fixture generation method could precisely model the workspace. We also implemented force feedback, visual feedback, and motion scaling feedback in the microsurgical robotic system in order to inform the surgeon of the risk of collision. Performance of each feedback method and their combinations was evaluated in two experiments. The experimental results showed that the combination of the force and the visual feedback methods were the most beneficial for avoiding collisions.

Neurosurgical procedures require precise and dexterous manipulation of a surgical suture in narrow and deep spaces in the brain. This is necessary for surgical tasks such as the anastomosis of microscopic blood vessels and dura mater suturing. A hand-held multi-degree of freedom (DOF) robotic forceps was developed to aid the performance of such difficult tasks. The diameter of the developed robotic forceps is 3.5 mm, and its tip has three DOFs, namely, bending, rotation, and grip. Experimental results showed that the robotic forceps had an average needle insertion force of 1.7 N. Therefore, an increase in the needle insertion force is necessary for practical application of the developed device.

The 3-level circuit topology is a suitable option for increasing power density of DC/DC converters. The advantage is theoretically investigated in comparison with an interleaved topology using a set of coupled inductors. The prototype achieved a high power density of 26.8 kW/liter at 60 kW output with 97.5% efficiency.

Among eco-friendly electric vehicles, some incorporate DC/DC converters in their electrical drive systems to make full use of their power sources. For increasing the power density of the converters, a 3-phase interleaved converter using an inductor set of inductors and close-coupled inductors is investigated. The inductor set of a 3-phase topology is shown to be smaller in size and lose less power in comparison to that of a 2-phase topology while meeting the required specifications for high powered electric vehicles having a 200∼400 volt battery. The 3-phase converter using the inductor set was designed on the condition of using IGBT with a switching frequency of 15 kHz. It achieved a high power density of 21.4 kW/liter at 120 kW output on a boost ratio of 1.38 with 98.0% efficiency and it achieved an efficiency of more than 97% in a frequent usage zone with low temperature rise.

The DC-DC converter using coupled inductors is known as one of the topologies that achieve higher power density. This paper focused on this topology especially using extreme close-coupled inductors (ECCI). Following the elucidation of design guidelines for the coupled inductor theoretically, the superiority of the interleaved converter using ECCI in terms of reducing the size and losses in the magnetic components is demonstrated clearly through comparison with an interleaved converter using a set of looser-coupled inductors and a conventional single inductor converter. The effect of increasing a magnetic coupling factor of a set of coupled inductors from 0.980 to 0.999 is investigated by comparing it with other inductors of interleaved converters. The high power prototype converter with the coupling factor of 0.999 provides excellent performance with a time rating power density of 25.6 kW/liter.

Integration of many functions in mobile devices often results in the insufficiency of computing resources and security problems. We utilize multiple computing modules distributed in the environment as external resources, and call this processor network system “UMP (Ubiquitous Multi Processor) system.” In our previous research, the basic architecture of a UMP system and its communication theory were verified. This paper evaluates the correlation between data granularity and system performance for applications with variable data granularity and verifies the usefulness of these parameters in dynamic scheduling necessary to construct intelligent systems. A JPEG encoding application was evaluated on the UMP system with six sub-functional modules. Optimization of data granularity shows 180% improvement of system performance. The experimental result shows that data granularity of inter-PE communication could be an important parameter in optimizing the system architecture and dynamic scheduling. Moreover, the result shows the possibility of further performance improvement through optimization of data granularity by focusing on individual modules.

This research concerns a system, which is called Ubiquitous Multi-Processor (UMP) system, which constructs dataflow network dynamically by connecting function-specific execution modules. The software model of the system was developed consisting only of application-specific execution modules (SS-PE) providing fixed functions. We developed a general-purpose execution module (GP-PE) which performs equivalent function to SS-PE by downloading the software library to improve the efficiency of development and reconfigure the function dynamically. The GP-PE was evaluated on the loading time of the library, the processing time of a color space conversion application, and the configuration time of processing on a network. The results of evaluation show that the GP-PE achieves equivalent performance to the SS-PE. Furthermore, the GP-PE does not degrade the system performance regarding dynamic system configuration if the library becomes hundreds of megabytes. This result shows that the GP-PE is suitable for the UMP system in general use.

Among the specifications of eco-friendly electric vehicles, some will incorporate voltage converters in their systems to make full use of their power sources. The DC-DC converter using coupled inductors is known as one of converter types that may achieve higher power density. This paper focused on this circuit type especially using close-coupled inductors. Following, the elucidation of design guidelines for the close-coupled inductors theoretically, the superiority of the circuit in terms of reducing the size and losses in the magnetic components was demonstrated clearly through comparison with coupled inductors with looser coupling used in interleaved boost circuits and an inductor of boost chopper circuits. Finally, test results for a prototype of the proposed converter achieved a maximum power density of 24.7 kW/liter and a maximum efficiency of 98.4 % on an output of 42 kW (a maximum input current of 233 A) for a time rating of a few minutes.

Pervasive computing provides an attractive vision for the future of computing where contextual intelligent services will be available anywhere at any time. However, how to integrate distributed resources existed among heterogeneous devices to build pervasive applications that can constantly adapt to the highly dynamic computing environment is still a challenge. By analyzing the pipelining feature within a user task and exploiting the parallelism among ubiquitous processors, we propose UMP-PerComp, a ubiquitous multiprocessor-based pipeline processing architecture to support high performance pervasive application development. UMP-PerComp is an integrated comprehensive framework that makes the development of pervasive applications easier. It includes a set of common services such as context management, resource management, service migration, topology management, that help to build applications and directly simplify the task decoupling and service composition. We describe the design and implementation of UMP-PerComp in this paper. Besides, we develop a distributed JPEG encoding application successfully on the UMP-PerComp. Our experience confirms that UMP-PerComp is a flexible, scalable and practicable framework with high performance.

This paper proposes a novel control strategy of a matrix converter, which features direct instantaneous-active-and active-and active-and reactive-power control of the converter. The power can directly be regulated by selecting an optimum switching state with a relay (bang-bang) control algorithm; thus an ultimately high-speed response of the power control is achieved. A theoretical aspect of the control is discussed, and some computer simulation results are presented to confirm the basic controllability of the technique. In addition, several operation characteristics are examined through experimental tests, using a 1.5-kW prototype. The maximum efficiency and total input power factor of the experimental setup were 95.4 % and 99.9 % at 1.5-kW load with 30-Hz output frequency, respectively. Also, the total harmonic distortion of the input current was 5.9 % at the rated load condition. These results prove feasibility and effectiveness of the proposed strategy.

This paper describes a novel control strategy of a current-source PWM rectifier, which is based on relay control of instantaneous active and reactive power, and presents its experimentally examined operation characteristics, followed by a theoretical derivation of the control algorithm. The most important feature of this strategy is a direct selection of switching modes of the PWM rectifier to restrict errors between the feedback values and the command values of the active and reactive power. Therefore, a theoretical analysis on relationship between the instantaneous power and the switching modes of the PWM rectifier is deeply investigated, which is essential to compose a switching mode table in the controller. Feasibility of the proposed strategy is experimentally verified, using a prototype setup. As a result, 92.7-% maximum efficiency and 99.9-% maximum total power factor are confirmed through the experimental tests.

We have developed a real-time encoder chipset which completely complies to the standard ISO/IEC13818-2|ITU-TH.262 (also known as "MPEG2 Video"), for the Main Profile at Main/High Level. This set consists of the following five chips: the "PRE" (Pre-processing) chip, the "CME" (Coarse Motion Estimation) chip, the "COD" (Predictive Coding) chip, the "QVL" (Orthogonal Transformation, Quantization, and Variable Length Coding) chip, and the "FME" (Fine Motion Estimation) chip. One set of these five chips is sufficient for real-time encoding of source images equivalent to the ITU-RBT.601 standard, and by connecting eight sets together, HDTV level real-time encoding is possible.

Japan's Ministry of International Trade and Industry (MITI) is committed to the construction of a society with minimized inputs of energy and resources and minimized outputs of wastes and pollutants. To achieve this goal, a socio-economic system with sustainable material cycles needs to be developed, and MITI has been supporting the development through various policy measures, including legislation to promote recycling. The ISO 14000 series is regarded as a key mechanism in the facilitation, evaluation and realization of this system. Local government activities that support the goals of zero emissions societies are also being encouraged through the "Eco-Town" project.