• Proceedings of the KIEE Conference
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• 2006.11a
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• pp.36-39
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• 2006

This paper proposes a support vector machine (SVM) based power system voltage stability classifier using local measurement data. The excellent performance of the SVM in the classification related to time-series prediction matches the real-time data of PMU for monitoring power system dynamics. The methodology for fast monitoring of the system is initiated locally which aims to leave sufficient time to perform immediate corrective actions to stop system degradation by the effect of major disturbances. This paper briefly describes the mathematical background of SVM, and explains the procedure for fast classification of voltage stability using the SVM algorithm. To illustrate the effectiveness of the classifier, this paper includes numerical examples with a 11-bus test system.

• International Journal of Highway Engineering
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• v.16 no.3
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• pp.101-107
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• 2014

PURPOSES : This study deals with the pedestrian accidents in case of Cheongju. The goals are to develop the pedestrian accident model. METHODS : To analyze the accident, count data models, truncated count data models and Tobit regression models are utilized in this study. The dependent variable is the number of accident. Independent variables are traffic volume, intersection geometric structure and the transportation facility. RESULTS : The main results are as follows. First, Tobit model was judged to be more appropriate model than other models. Also, these models were analyzed to be statistically significant. Second, such the main variables related to accidents as traffic volume, pedestrian volume, number of Entry/exit, number of crosswalk and bus stop were adopted in the above model. CONCLUSIONS : The optimal model for pedestrian accidents is evaluated to be Tobit model.

• The Journal of Sustainable Design and Educational Environment Research
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• v.8 no.2
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• pp.12-21
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• 2009

The purpose of this study is to suggest a scheme to provide children safer and more comfortable walking circumstances by survey current walking circumstances of school zone ways. First, to avoid pedestrian roads being interrupted and to expand waiting space near school zone ways, several measures are needed including fixing roads, using schools' unemployed spaces and building additional gateway. Second, pedestrian crossings in front of school gate should be located at least 23.16m away from the left side of the gate. Third, on narrow path which cross main streets, the interval of pedestrian signal should be extended as against of the moment. And traffic calming facilities should be built on accurate position. Fourth, to secure pedestrians' safety and field of view, trees lining streets and any obstacles located within 10m from bus stop sign should be removed. Finally, education system about school zone ways should be improved to help children get used to more complicated roads' conditions.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.519-523
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• 2003

This paper describes the communication system of sequencing sorter. Generally sequencing sorter is a machine that sorts mails by delivery order. And designed sequencing sorter is composed of 5 physical modules. So, it is necessary to communicate with each module and to control this communication. A computer called Machine Management Computer, controls this. This paper is about the communication system with MMC and module controllers. This is PC-based, asynchronous full-duplex 4-wire serial systems. 3 protocol layers are presented and stop-and-wait flow control is adopted. Because designed sequencing sorter has to be operated high speed about 27,000 letters per hour, we analyzed the network traffic in the worst case. So, we could find that the communication system has to use above 115,200bps speed.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.33 no.12
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• pp.85-92
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• 2017

The purpose of this research is to provide a basic framework of design guideline for elderly people who can live without inconvenience. It is time to think about how to create an age-friendly city for the Korean society which is rapidly advancing in population aging. Design guidelines studied in this research cover not only architecture but also urban, landscape and transportation fields, and consist of 90 items in 7 areas (park&open space, buildings, pedestrian street, crosswalk&bicycle lane, bus stop&subway station, parking housing). The importance of each item and each area were surveyed to verify objectivity. The result of importance of each item can be used to select design guidelines which can be applied first to create an aged-friendly physical environment.

• Elastomers and Composites
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• v.56 no.2
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• pp.85-91
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• 2021

In this study, different types and shapes of various particles produced on the asphalt pavement road were analyzed. Road dust at a bus stop was collected and was separated as per their sizes by using a sieve shaker. Tire-road wear particles (TRWPs), asphalt pavement wear particles (APWPs), mineral particles, plant-related particles, glass beads, glass particles, road paint wear particles, plastic particles, and fibers were observed herein. The types and shapes of the particles varied depending on their sizes. TRWPs larger than 500 ㎛ were not observed. TRWPs with a size of 212-500 ㎛ were rarely present, but many TRWPs with a size smaller than 212 ㎛ were observed. APWPs were observed for whole-particle sizes of below 1,000 ㎛. A variety of particles on the road would lead to lower friction between the tires and the road, thereby increasing the braking distance of vehicles. Most of the particles include mineral particles, glass particles, and APWPs with rough surfaces. Therefore, the abrasion of the tire tread would accelerate owing to friction with the tough particles.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.11a
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• pp.380-383
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• 2020

본 작품은 코로나 바이러스로 인한 언택트 서비스의 부각과 더불어, 대중교통 이용시 승객들이 하차에 신경쓰지 않고 자신의 일에 집중 할 수 있도록 지원하기 위해 제작된 서비스이다. 버스 하차 전(혹은 승차 시) 미리 희망하는 하차 지점을 예약해놓으면 해당 정류장에 자동으로 버스의 하차벨을 울리게 된다. 스마트폰 앱과 버스에 설치된 단말을 활용하여 추가적인 설치비용을 절약하며, 이 후 완성된 시스템을 발전시켜 사용자별 타겟광고가 가능해지면 버스회사의 부족한 재원을 보다 확보할 수도 있다.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.11a
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• pp.1031-1033
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• 2022

본 논문에서는 모든 사람들이 더 안전하고 편리하게 대중 교통을 이용하기 위해 탑승할 버스를 미리 예약할 수 있는 예약 버튼 시스템과, 단말기에 카드를 찍지 않아도 탑승 버튼을 통해 요금을 자동 결제하는 시스템, 그리고 버스 내에서 직접 stop 버튼을 누르지 않아도 앱의 하차 버튼을 누르면 자동으로 벨이 울리는 어플리케이션 시스템을 제안했다. 기존 버스 관련 앱 대부분이 버스 도착 예정시간, 경로, 정류소 정보들만 있다. 본 논문에서는 여기서 더 나아가 탑승할 버스 예약, 요금 결제, 하차벨 기능을 더한 어플리케이션 기술을 제안했다.

• Journal of Korean Society of Transportation
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• v.30 no.1
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• pp.149-159
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• 2012

The evaluation of public transit service quality is more complicated than evaluating other aspects of transportation service. Although various measures of effectiveness [MOEs] for transit service have been studied and applied, a more comprehensive and accurate MOE is still required. In the past, either data from user surveys or the experience of bus agency administrators and/or engineers used to measure the quality of service. However, recently, with reliable and accurate real time data from BMS(Bus Management System) and BIS(Bus Information System), more reliable and accurate MOEs are available. This study develops a service evaluation model from users' perspectives, which is based on user' cost models that consider passenger access time, riding time, waiting time, and discomfort due to in-vehicle overcrowding, violation of traffic laws, and accident rate. For validating proposed model, data from the BMS and transit-fare cards (T-Money Card) for Seoul's No. 472 main bus line were used. Models developed in this study provided reliable results.

• Korea Science and Art Forum
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• v.20
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• pp.279-292
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• 2015

As the aging society is rapidly coming, the needs for the elderly-friendly living environments was also increasing. The purpose of this study was to examine how frequently 25 neighborhood facilities were used by the elderly and what facility they wanted to be arranged within their walking distance. The subject of this study were 158 elderlies who were their ages of more than 65 years and lived in Busan. The data were collected by using an one to one interview method. Findings were as follows; 1) The elderly used very frequently facility for the elderly such as a senior center, walking road, and park and green space. Also, bus stop, traditional market, and resting facilities were used relatively frequently. 2) Some neighborhood facilities were used not frequently, but periodically. 3) Using frequencies of some neighborhood facilities were different by the elderly's characteristics. 4) Among 25 neighborhood facilities, the facilities which the old persons wanted to be arranged within walking distance were medical clinics, facilities for the elderly, subway station, bus stop, traditional market, park and green space, walking road, and food market/convenience store.