• 연구논문집
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• s.28
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• pp.5-12
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• 1998

Test Results and Status of development of the urban transit maglev system (UTM-0l) are reported. Maglev Project Team in KIMM, in cooperation with Hyundai Precision Company and the Korea Electrotechnology Research Institute (KERI). has successfully finished the second stage development project (1995.5-1998.8) and demonstrated a prototype two vehicle consisted urban maglev train operating in the speed range of 50 km/h. In this paper, we report various test results of the UTM-01 system. present status of quo and future prospect, and what have been done so far to improve the performance of the maglev system overall.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.190-198
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• 2020

For domestic urban railways, which have a 19.7% aging rate, a performance evaluation is necessary to establish capital improvement investment plans. The performance evaluation, which was recently enacted in the relevant law, points out the excessive time and effort for acquiring data and evaluation. This study developed a performance evaluation simulation prototype using a virtual reality (VR) method to use as training contents for railway performance evaluations. The practical use of the VR technique to reduce the working time under poor environment conditions was confirmed through a literature review. A survey and consultation were conducted for urban railway experts to determine the weight of the performance evaluation items and the facility breakdown structure. This information was utilized to develop performance evaluation sheets for simulation. Based on the evaluation sheet, a training content prototype that evaluates the performance of platform safety doors was developed using VR techniques with HTC VIVE equipment. VR simulation tests were conducted for six players, and the prototype was sufficiently advantageous for a visual confirmation of the facility information. The result is expected to be useful for engineers to understand the performance evaluation process efficiently before an actual performance evaluation of urban railway facilities.

• Transactions of the Korean Society of Automotive Engineers
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• v.23 no.2
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• pp.161-168
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• 2015

Recently, due to various environmental problems such as global warming, increases of international oil prices, exhaustion of resource, a paradigm of world automobile market is rapidly changing from conventional vehicles using internal combustion engine to eco-friendly vehicles using electric power such as EV, HEV, PHEV and FCEV. Generally, in order to measure fuel consumption and pollutant emissions of cars, chassis dynamometer tests are performed on various driving cycles before actual driving test. There are many driving cycles for performance evaluation of conventional vehicles. However, there is a lack of researches on driving cycle for EV. In this study, the urban driving cycle for performance evaluation of electric vehicles was developed. This study is composed of two parts. In the part 1, the urban driving cycle 'GUDC-EV(Gwacheon-city Urban Driving Cycle for Electric Vehicles)' was developed by using driving data, which were obtained through actual driving experiment, and statistic analysis with chronological table. In this paper part 2, in order to verify the developed driving cycle GUDC-EV, virtual EV platforms were configured and simulations were performed with actual driving data using In addition, simulation results were compared with existing driving cycles such as FTP-72, NEDC and Japan 10-15.

• Korean Journal of Remote Sensing
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• v.39 no.5_4
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• pp.1145-1153
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• 2023

Urban trees play an important role in absorbing carbon dioxide from the atmosphere, improving air quality, mitigating the urban heat island effect, and providing ecosystem services. To effectively manage and conserve urban trees, accurate spatial information on their location, condition, species, and population is needed. In this study, we propose an algorithm that uses a high-resolution urban tree cover map constructed from deep learning approach to separate trees from the urban land surface and accurately detect tree locations through local maximum filtering. Instead of using a uniform filter size, we improved the tree detection performance by selecting the appropriate filter size according to the tree height in consideration of various urban growth environments. The research output, the location and height of individual trees in human settlement over Suwon, will serve as a basis for sustainable management of urban ecosystems and carbon reduction measures.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1754-1759
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• 2011

The purpose of this paper is to provide basic information on how to make better policies that improves efficiencies of urban railways and to derive policy directions using DEA (data envelopment analysis) model. Through this paper, I can identify whether or not the urban railway service has an excellent performance, if there are any structural problems. I analyzed the efficiency by means of measuring the technical efficiencies of Korean urban railways, these were estimated with data envelopment analysis. The inputs considered are the length of urban railway lines, the number of staff, the operating cost, the number of cars, the number of stations, and the outputs are the cars movement, the traffic of passenger, and the revenue.

• Journal of Auto-vehicle Safety Association
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• v.10 no.1
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• pp.32-37
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• 2018

This paper proposes autonomous speed control strategy for an Electric Vehicle on urban road. SNU campus road is used to reperesent urban road situation. Motor efficiency of driving on campus circulation road can be improved by controlling velocity properly. Given information of campus road, especially slope of road, acceleration is selected from candidate, considering consumed power, human factor and driving time. To apply urban situation, preceding vehicle is also considered. With preceding vehicle, acceleration is defined according to clearance and relative velocity. Acceleration is bounded in normal range. Proposed acceleration control method is activated with proper velocity range for campus circulation road. With acceleration control, motor efficiency becomes better than driving with constant vehicle. To evaluate the performance of proposed acceleration controller, simulation study is conducted via MATLAB.

• Journal of Korean Society on Water Environment
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• v.20 no.6
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• pp.703-707
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• 2004

In this study, a simple regression model is proposed in order to analyse the effect of population and urban land use on the water quality of Paldang lake, Gyeonggi. As a comparison result with Qua12E water quality model, the proposed model shows very good predicting performance in simulating several alternative scenarios. In order to accomplish BOD 1ppm of Paldang lake, various model applications show that the population incoming and urban land use management should be afoot in addition to stricter outflow water quality from sewer treatmement systems.

• International Journal of High-Rise Buildings
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• v.11 no.3
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• pp.207-219
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• 2022

During the structural design of urban over-track high-rise buildings, two problems are most likely encountered: the abrupt change of story stiffness between the podium and the upper towers, as well as the demand for train-induced vibration control. Traditional earthquake-resistant structures have to be particularly designed with transfer stories to meet the requirement of seismic control under earthquakes, and thus horizontal seismic isolation techniques are recommended to solve the transfer problem. The function of mitigating the vertical subway-induced vibration can be integrated into the isolation system including thick rubber bearings and 3D composite vibration control devices. Engineering project cases are presented in this paper for a more comprehensive understanding of the engineering practice and research frontiers of urban over-track high-rise buildings in China.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.60 no.4
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• pp.200-205
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• 2011

In multipath fading channel, diversity is essential to mitigate the impairments. In this paper, we have proposed the angle diversity scheme called ATTD(Angle Time Transmit Diversity) instead of Alamouti's STTD(Space Time Transmit Diversity) and have analyzed the performance of the proposed scheme when signal powers caused by the transmission to different angles are different. Based on it, we have measured the wireless vector-channel in the urban area, which has lots of high-story buildings, using the data collected from the 8 by 4 smart array antenna system that we made. According to the measured data, the received signals from different angles have different signal powers. Our performance analysis results show that the proposed scheme has better performance than the space diversity scheme when the received path signal power is at least -7dB compare to the strongest path signal power.

• International Journal of High-Rise Buildings
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• v.5 no.2
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• pp.105-115
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• 2016

In the process of exploring sustainable development, major cities in China are expanding metro systems as a strategy to reduce the negative environmental and social consequences of fast-paced motorization. A metro station is not only a transportation node, but also a place where diverse activities can be performed. Therefore, the realization of the spatial potential for human interaction is the essence of the strategy for integrated development in metro station areas. For this paper, 10 well-developed metro stations in Central Shanghai were selected to investigate the correlation between accessibility and spatial performance in station areas. The spatial performance in station areas is significantly affected by metro configuration. However, both vehicle and pedestrian accessibility show weak influence on spatial performance. A synergistic model was then developed to provide quantitative support for transit-oriented development in metro station areas.