• Transactions of the Korean hydrogen and new energy society
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• v.18 no.1
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• pp.60-66
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• 2007

In terms of the vehicle efficiency, a fuel cell hybrid system has advantages compared to a conventional internal combustion engine and a fuel cell alone-powered system. The efficiency of the fuel cell hybrid vehicle mainly depends on the maximum power of the fuel cell and therefore it is important to decide the design value of the fuel cell maximum power. In this paper, to estimate the performance of the fuel cell hybrid mini-bus in the design phase the simulator based on the models for the fuel cell stack, the electric battery, the fuel cell balance of plant, the controller, and the vehicle itself is proposed. Additionally, the hybrid mini-bus efficiencies with several different fuel cell powers are simulated for a city driving schedule and are compared on another. Consequently, the proposed simulation scheme is useful to determine the best design value of the fuel cell hybrid vehicles.

• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.55-57
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• 2007

A Power control and Distribution Unit (PCDU) plays roles of protection of battery against overcharge by active control of solar array generated power, distribution of unregulated electrical power via controlled outlets to bus and instrument units, distribution of regulated electrical power to selected bus and instrument units, and provision of status monitoring and telecommand interface allowing the system and ground operate the power system, evaluate its performance and initiate appropriate countermeasures in case of abnormal conditions. In this work, we perform the preliminary design of a PCDU for the small Low Earth Orbit (LEO) Satellite applications. The main constitutes of the PCDU are the battery interface module, solar array regulators with maximum power point tracking (MPPT) technology, heater power distribution modules, internal converter modules for regulated bus voltage generation, power distribution modules of unregulated and regulated primary bus, and instrument power distribution modules.

• Journal of Information Processing Systems
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• v.14 no.1
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• pp.270-279
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• 2018

PCI Express (PCIe) bus, which was only used as an internal I/O bus of a computer system, has expanded its function to outside of a system, with progress of PCIe switching processor. In particular, advanced features of PCIe switching processor enable PCIe bus to serve as an interconnection network as well as connecting external devices. As PCIe switching processors more advanced, it is required to consider the different adapter card architecture. This study developed multipurpose adapter cards by applying an on-board optical module, a latest optical communications element, in order to improve transfer distance and utilization. The performance evaluation confirmed that the new adapter cards with long cable can provide the same bandwidth as that of the existing adapter cards with short copper cable.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.2
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• pp.378-385
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• 2016

The internal circuit of the bus-bar for an electrical switch board is a prime cause of electric shock and short circuit accidents due to the exposure of live parts. Electrical fires can also be caused by animals and foreign substances in the switchboard that connect the components with a difficult structure resulting in overheating due to an increase in contact resistance. Preventing these types of accidents is a prime concern in the manufacturing process, such as cutting and bending. In this study, the cutting bus bar of a switch board contained improved modules as a flame retardant that isolates a separate blocks to prevent such problems. This was implemented as a scalable and flexible means of reducing electrical switchboard hazards to offer a safe switch board bus-bar structure of a new connecter type

• Journal of Auto-vehicle Safety Association
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• v.15 no.4
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• pp.79-87
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• 2023

In recent years, the population of children has been declining in Korea. Moreover, the phenomenon of elementary school closures is on the rise, particularly in non-urban and some new city areas, highlighting the need for school buses for children. Despite the mandatory safety features in place, accidents involving school buses for children are on the rise, underscoring the need for improvement in the safety of these vehicles. While various studies have been conducted to enhance the safety of children during their school commute, there has been a notable gap in research analyzing the school commuting environment concerning the vehicle safety of these buses. Hence, this study aims to develop a set of service evaluation criteria for school bus routes, considering vehicle safety through the Analytic Hierarchy Process (AHP). By conducting a survey to gather information on the current status of school buses for children and through questionnaires targeting stakeholders in the school bus sector, the study analyzed requirements and operating conditions. These results were used to select evaluation criteria and structure the hierarchy based on the external and internal aspects of school bus services. Through AHP surveys conducted based on the designed criteria, experts identified safety as the most crucial aspect, with a specific emphasis on Vehicle Safety. Using these developed service evaluation criteria, the study plans to identify service-vulnerable routes through a real route analysis and recommend improvements, with the ultimate goal of creating a safe and convenient school commuting environment for children.

• Journal of Advanced Navigation Technology
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• v.16 no.6
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• pp.1024-1031
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• 2012

In the past, the part of development of that is used for the military aviation target or reconnaissance is being extended to the range of application not only reconnaissance but also civilian industry as the introduction of the newest IT technology and the technical evolution. The Civilian low-cost UAV that is expected growth at the market of UAV in the world is accelerated to the extended applicability in the fields. However, The UAV study is recently focused on the Link and The Data bus because the main decision of the civilian UAV system configuration is not suitable to determinate the factory of price. In this paper is analysed the UAV data bus through the simulation in same condition both the CAN Bus which used the automobile industry and the MIL-STD-1553B which is used the aviation industry. As a comparison result, we identified that the CAN Bus of conventional configuration is possible to transmit the data without the need for a separate coupler equipment against the MIL-STD-1553B data. Thus, we identified that the CAN bus is capable to apply as a low-cost UAV internal data bus to optimize configuration and weight than 1553B.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.4
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• pp.24-31
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• 2007

Up to date, a lot of bus protocol and bus architecture are released though most of them are based on the shared bus architecture and inherit the limitation of performance. SNP (SoC Network Protocol), and hence, SNA (SoC Network Architecture) which are high performance on-chip-bus protocol and architecture, respectively, have been proposed to solve the problems of the conventional shared bus. We refine the SNA specification and improve the performance and functionality. The performance of the SNA is improved by supporting simultaneous routing for bus request of multiple masters. The internal routing logic is also improved so that the gate count is decreased. The proposed SNA employs XSNP (extended SNP) that supports almost perfect compatibility with AMBA AHB protocol without performance degradation. The hardware complexity of the improved SNA is not increased much by optimizing the current routing logic. The improved SNA works for IPs with the original SNP at its best performance. In addition, it can also replace the AMBA AHB or interconnect matrix of a system, and it guarantees simultaneous multiple channels. That is, the existing AMBA system can show much improved performance by replacing the AHB or the interconnect matrix with the SNA. Thanks to the small number of interconnection wires, the SNA can be used for the off-chip bus system, too. We verify the performance and function of the proposed SNA and XSNP simulation and emulation.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.11
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• pp.57-62
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• 2011

In this paper, an efficient architecture for MFVLD(Multi-Format Variable Length Decoder) which can process H.264, MPEG-2, MPEG-4, AVS, VC-1 bitstream is proposed. The proposed MF-VLD is designed to be adapted to the MPSOC (Multi-processor System on Chip) architecture, uses bit-plane algorithm for the processing of inverse quantized data to reduce the width of AHB bus. External SDRAM is used to minimize the internal memory size. In this architecture, the adding or removing each variable length decoder can be easily done by using multiplexor. The designed MF-VLD can be operated in 200MHz at 0.18um process. The gate size is 657K gate and internal memory size is 27Kbyte.

• Journal of the Korean Society of Safety
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• v.36 no.1
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• pp.72-79
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• 2021

This basic study introduces the concept of S-BRT and develops dwell time estimation models that consider road geometry and S-BRT characteristics for a signal operation strategy to meet the S-BRT's operational goal of high speed and punctuality. Field surveys of low-floor buses similar in shape to S-BRTs and data collection of passengers, station elements, vehicle elements, and other factors that can affect stop times were used in a regression analysis to establish statistically significant dwell time estimation models. These dwell time estimation models are developed by categorizing according to the locations of the signal or sidewalk that have the most impact on the dwell time. In this way, the number of people boarding and alighting the bus at the crowded door and the number of people boarding and alighting the bus at the front door considering the internal congestion was analyzed to affect the dwell time. The estimation dwell time models in this study can be used in the establishment of strategies that provide priority signals to S-BRTs.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.12
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• pp.2184-2188
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• 2007

We developed a novel method of partial discharge(PD) location based on the fact that the waveform of PD signal propagate along the GIB (Gas Insulated Bus) is composed of several modes of electromagnetic wave with different group velocities and cut-off frequencies. From the PD waveform, measured at a broadband PD sensor attached on the GIB, we could derive arrival time and frequency components of different modes using the short term Fourier transform or etc. After the group velocities of different modes are calculated, the location of the PD source could be estimated. To show the effectiveness of this new locating method in a real on site application, we used this method to locate the position of a PD source at a 76 m long 345 kV GIB substation. The estimated location of the PD source using the method proposed above was in good agreement with the actual location found from the inspection result of internal component in the GIB with 2.4% of the estimation error.