• Journal of the Korean Physical Society
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• 제73권10호
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• pp.1410-1419
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• 2018

A skier's motion was analyzed by a simple model consist of point mass m and a single rod connected to a single ski plate. We studied the conditions for the stable ski turn as functions of the linear velocity and the radius of the turn. The solutions for the stable ski turn in our model do not require any extra skier's movement to complete a stable circular turn. The solution may then give the skier the most comfortable skiing method without any active movement to control the ski. The generalized force supporting the point mass from the ski plate was calculated. We obtained the force from the ground (rebound force) without any geometrical structure of the ski plate. Adding an active movement to the direction of the ski plate, the conditions for the stable ski turn were also analyzed. Our result gives some insight for the skier who wants to develop technique.

• 한국운동역학회지
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• 제24권3호
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• pp.201-207
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• 2014

This study investigated the center of mass and lower extremity kinematic patterns between carved and basic paralell turn during alpine skiing. Six experienced skiers (age: $20.67{\pm}4.72yrs$, body mass: $72.67{\pm}7.15kg$, height: $171.00{\pm}5.51cm$) participated in this study. Each skier were asked to perform carved and basic paralell turn on a $22.95^{\circ}$ groomed slope. Each turn was divided into the initiation phase, steering phase 1 and 2. The results of this study show that the carved turn spent significantly less running time than basic paralell turn at all three phases (p<.05). Also vertical displacement of the center of mass was significantly greater in carved turn at all three phases, whereas inward leaning angle of the center of mass was significantly greater in carved turn at the steering phase 1 and 2 (p<.05). Bilateral knee and hip joint angle were significantly greater in basic paralell turn at the initiation phase and the steering phase 2 (p<.05). On the other hand, left knee and hip joint angle were significantly greater in basic paralell turn at the steering phase 1 (p<.05). In order to perform successful carved turn, we suggest that skiers should coordinate bilateral knee and hip joint angles to adjust the center of mass, depending on three ski turn phases.

• Journal of Power Electronics
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• 제7권1호
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• pp.81-88
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• 2007

This paper presents a new approach to the automatic control of the turn-off angle used to excite the Switched Reluctance Motor (SRM) employed in electric vehicles (EV). The controller selects the turn-off angle that supports and improves the performance of the motor drive system. This control scheme consisting of classical current control and speed control depends on a lookup table to take the best result of the motor. The turn-on angle of the main switches of the inverter is fixed at $0^{\circ}C$ and the turn-off angle is variable depending on the reference speed. The motor, inverter and control system are modeled in Simulink to demonstrate the operation of the system.

• 전기전자학회논문지
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• 제22권1호
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• pp.143-148
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• 2018

본 논문에서는 자동으로 차량의 방향지시등 점멸 기능을 제어할 수 있는 새로운 방식의 방향지시등 제어 시스템을 제안한다. 차량의 진행 방향에 대한 운동 모멘텀을 인식하기 위한 모션 인식 센서를 채용하여, 제안된 방식의 ADAS 시스템은 차선 변경시 운전자가 방향지시등 레버를 조작하지 않을 경우에 차량의 진행 방향을 감지하여 자동으로 방향지시등의 점멸을 제어하도록 개입할 수 있다. 제안된 제어 시스템은 오토바이 실차에 장착되어 운전자의 안전을 위한 운전자 지원 시스템(ADAS) 으로서의 기능을 확인하였다.

• 한국건축시공학회지
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• 제6권1호
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• pp.93-99
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• 2006

In the inner turn key constructions the problems of uniform types are repeatedly occurred, and, especially, many problems happen up to the stage of pre-construction(from a bid to a contract) owing to the specialties of the turn key constructions. So the claim factors of the Korean turn key constructions were abstracted through the literature searches, the site document examinations, the case studies and the interviews with the experts. When the technicians meeting the interior turn key constructions for the first time and working here now are well acquainted with only these factors, many claims will be prevented. By analysing the degree of claims by claims factors through the questionnaires to the experts about the abstracted factors and surveying the amount of the claims through the case studies, what factors exerted how much of influence on the claims was tested and analyzed. Proposing the response devices to the factors affecting the claims much led the technicians in charge of internal turn key constructions to the prevention and the proper solution of the site claims.

• 대한교통학회:학술대회논문집
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• 대한교통학회 1998년도 Proceedings 제34회 추계 학술발표회
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• pp.236-244
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• 1998

When the capacity and traffic operation at signalized intersections are analyzed in Korea, the unprotected left-turn saturation flow rate, which is an important parameter for the analysis, is estimated form the USHCM model. thus, exact analysis of the left-turn is not possible because of the difference of traffic environments between two contries. In order to improve this problem, it is undertaken in this study to develop techniques for the estimation of unprotected left-turn saturation flows based on Korean drivers' data. As study intersections, signalized or unsignalized intersections on the 6, 4 and 2 lane streets are selected. the data for the saturation flow measurement and gap-acceptance behavior analysis are inputed in a notebook computer on the sites. The critical acceptance gaps of the 6, 4, and 2 lane streets are analyzed to be 6.0 secs, 4.6 secs, and 4.3 secs respectively. the average minimum headway of the left-turn vehicle was observed to be 2.6 secs. As the model to estimate unportected left-turn saturation flows, the drew model is recommended for 6 and 4 lane streets, and a graph is suggested for the 2-lane street. As the values of the parameters of the Drew model, the 2.6 secs of this study is recommended for the average minimum headway of the left-turn. But, the critical acceptance gap varies according to the approach speed of opposing traffic and driver population, it requires field survey to measure the gap of an intersection; however, the values of the gaps studied in this study may be used for the general intersections in urban area in Korean.

• 한국중재학회지:중재연구
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• 제13권2호
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• pp.353-376
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• 2004

In the inner turn key constructions the problems of uniform types are repeatedly occurred, and, especially, many problems happen up to the stage of pre-construction(from a bid to a contract) owing to the specialties of the turn key constructions. So the claim factors of the Korean turn key constructions were abstracted through the literature searches, the site document examinations, the case studies and the interviews with the experts. When the technicians meeting the interior turn key constructions for the first time and working here now are well acquainted with only these factors, many claims will be prevented. By analysing the degree of claims by claims factors through the questionnaires to the experts about the abstracted factors and surveying the amount of the claims through the case studies, what factors exerted how much of influence on the claims was tested and analyzed. Proposing the response devices to the factors affecting the claims much led the technicians in charge of internal turn key constructions to the prevention and the proper solution of the site claims.

• 한국측량학회지
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• 제36권3호
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• pp.153-164
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• 2018

Calculating the relevant length of left turn storages in urban intersections is very crucial in road designs. A left turn lane consists of deceleration lanes and left turn storages. In this study, we developed methods for calculating relevant lengths of left turn storages that vary at each intersection using UAV (Unmanned Aerial Vehicle) spatial images. Problems of conventional design techniques are applying the same number of left turn vehicles (N) using Poisson distribution without considering land use types, using a vehicle length that may not be measurable when applying the length of waiting vehicles (S), and using same storage length coefficient (${\alpha}$), 1.5, for every intersections. In order to solve these problems, we estimated the number of left turn vehicles (N) using an empirical distribution, suggested to use headways of vehicles for (S) to calculate the length of waiting vehicles (S) with a help of using UAV spatial images, and defined ranges of storage length coefficient (${\alpha}$) from 1.0 to 1.5 for flexible design. For more convenient design, it is suitable to classify two cases when possible to know and impossible to know about ratio of large trucks among vehicles when planning an intersection. We developed formula for each case to calculate left turn storage lengths of a minimum and a maximum. By applying developed methods and values, more efficient signalized intersection operation can be accomplished.

• 대한교통학회지
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• 제20권3호
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• pp.31-39
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• 2002

본 연구는 신호교차로의 좌회전 용량을 파악하기 위하여 bay차로를 포함한 좌회전 이동류의 용량산정 모형을 개발하는데 목적이 있다. 본 연구에서는 신호교차로의 혼잡을 완화시키기 위해 설치 운용되고 있는 좌회전 bay 차로의 용량을 파악하여 보다 정확한 용량산정치 적용을 통한 교차로 운영의 분석자료를 제시하고자 한다. 연구방법은 좌회전 bay길이를 20∼120m까지 변화시키며, bay차로와 전용차로에 대한 차두시간을 분석하였다. Bay차로의 용량산정을 위해 차두시간과 차량유출행태 특성에 따라 1구간(출발손실구간:SLP), 2구간(포화차두구간:SFP), 3구간(차로선택구간:LSP)으로 구분하여 분석하였다. 수집된 차두시간 자료로 차량 대기위치순서별로 분석하였다 자료의 통계적 검증을 통하여 구간대별 평균차두시간을 설정한 후, bay길이별 용량산정 모형을 도출하였으며, 이를 이용하여 bay길이별 좌회전 용량을 산출하였다.

• 대한교통학회지
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• 제14권3호
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• pp.45-59
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• 1996

The shortest path algorithm for route guidance is implicitly required not only to support geometrical variations of transportation network such as U-TURN or P-TURN but to efficiency search reasonable routes in searching mechanism. The purpose of this paper is to integrate such two requirements ; that is, to allow U-TURN and P-TURN possibilities and to cut down searching time in locating routes between two points (origin and destination) in networks. We also propose a new type of link searching algorithm which can solve the limitation of vine building algorithm at consecutively left-turn prohibited intersections. The test site is a block of Gangnam road network that has some left-turn prohibited and allowed U-TURN intersections. Four models have been identified to be comparatively analyzed in terms of searching efficiency. The Models are as follows : (i) Model 1 - Link Searching Dijkstra Algorithm without Searching Area Extraction (SAE) ; (ii) Model 2 - Link Searching Dijkstra Algorithm with SAE ; (iii) Model 3 - Link Searching Bidirectional Dijkstra Algorithm without SAE ; and (iv) Model 4 - Link Searching Bidirectional Dijkstra Algorithm with SAE. The results of comparative evaluation show that Model 4 can effectively find optimum path faster than any other models as expected. Some discussions and future research agenda have been presented in the light of dynamic route guidance application of the urban ATIS.