• 제목/요약/키워드: Car-following

검색결과 238건 처리시간 0.023초

운행차 배출가스 정밀검사 결과를 이용한 가솔린 차량에 대한 배출가스 특성 분석 (Analysis of Emission Gas Characteristics for Gasoline Vehicles using the Inspection Results of Car Emission)

  • 노현구
    • 한국분무공학회지
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    • 제23권3호
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    • pp.128-135
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    • 2018
  • In this study, the following conclusions could be obtained from the analysis of emissions contribution rates and features for contaminated emissions by 13,456 gasoline vehicles passed in the vehicle load test (ASM-idle) under the inspection year 2013 to 2017. It was confirmed that the contamination of the CO, HC, NOx by the displacement is reduced on over 3L engine. As a result of comparing the exhaust gas in the low speed idle mode and the AS2525 mode, the exhaust gas in the low speed idle mode was measured high. It is estimated that if ISG function is applied, emissions from idle condition will be reduced. NOx emissions were reduced when the engine power was above 200HP. It has been confirmed that the amount of exhaust emissions are significantly reduced for vehicles manufactured after 2004. As a result of analyzing the exhaust gas according to the season, it is judged that there is a correlation between HC and NOx according to the ambient temperature. The concentration of exhaust emission in vehicles with high accumulated distance increases, which is considered to be the result of aging of the vehicle.

이동 물체 추적을 위한 경계선 추출 (Boundary Line Extract for Moving Object Tracking)

  • 김태식;이주신
    • 전자공학회논문지T
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    • 제35T권2호
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    • pp.28-34
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    • 1998
  • 본 논문에서는 3차원 영상 처리 시스템을 이용한 이동 물체 추적을 위한 경계선 추출 알고리즘을 제시하였다. 이동 물체의 검출은 입력 영상에서 차 영상 기법을 이용하였고, 이동 물체 검출을 위한 검출 윈도우는 처리시간을 줄이기 위하여 4개의 예상영역과 물체영역으로 구성하였으며, 크기는 이동 물체의 크기와 중심 좌표에 대한 예측 계수에 의해 정하였고, 추적 카메라는 직류 모터에 의해 X, Y 방향으로 이동하도록 하였다. 모형 자동차를 이용하여 알고리즘을 수행한 결과, 최대 추적 시간은 2초였고, 추적 에러는 물체 크기의 6% 이하였다.

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개에서 견치 탈구를 동반한 앞쪽 하악골 골절의 수술적 정복 1례 (Surgical Repair of Rostral Hemimandibular Fractures with Canine Tooth Luxation in a Dog)

  • 윤헌영;강명곤;정순욱
    • 한국임상수의학회지
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    • 제26권4호
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    • pp.359-361
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    • 2009
  • 체중 25.2 kg 2년령 암컷 알라스카 말라뮤트 개가 교통사고 후 한강 동물병원에 내원하였다. 신체 검사에서 심한 유연과 견치 탈구를 보였으며 방사선 사진에서 앞쪽 하악골 골절이 관찰 되었다. 와이어링과 polymethyl methacrylate을 이용한 외고정을 실시하였다. 수술 7주 후 방사선 사진 검사에서 잘 발달 된 가골 형성이 골절 부위 피질에서 관찰 되었다. 수술 7주 후 핀이 제거 되었으며 정상적인 저작 운동을 관찰 할 수 있었다.

Positive Guidance 기법을 응용한 실시간 교통안전 경고정보 제공방안 (A Methodology for Providing More Reliable Traffic Safety Warning Information based on Positive Guidance Techniques)

  • 김준형;오철;오주택
    • 대한교통학회지
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    • 제27권2호
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    • pp.207-214
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    • 2009
  • 최근 각종 센서 및 통신기술의 발달은 과거에 비해 보다 미시적이고 폭넓은 교통자료의 수집과 운전자의 주행편의를 위한 다양한 방식의 정보제공을 실시간 환경에서 가능하도록 하였다. 본 연구에서는 Positive Guidance 기법을 응용하여 이와 같은 실시간 환경에서 적용 가능한 실시간 교통상충 분석 기반의 경고정보 제공 방안을 제안하고자 한다. 제안하는 시스템은 영상 이미지 추적 기법으로 개별차량의 주행패턴을 분석하여 인접 차량간 상충을 분석하고, ARIMA 모형을 이용하여 상충분석결과를 바탕으로 영상검지영역의 위험도를 예측한다. 위험도 예측을 통해 생성된 경고정보는 Positive Guidance 기법을 적용하여 영상검지영역 상류부에서 접근 중인 운전자에게 제공된다. 본 연구의 성과물은 향후 보다 교통사고 예방을 위한 보다 진보된 교통정보시스템의 개발 시 유용하게 활용될 것으로 기대된다.

Traumatic ventricular septal defect in a 4-year-old boy after blunt chest injury

  • Kim, Yun-Mi;Yoo, Byung-Won;Choi, Jae-Young;Sul, Jun-Hee;Park, Young-Hwan
    • Clinical and Experimental Pediatrics
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    • 제54권2호
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    • pp.86-89
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    • 2011
  • Traumatic ventricular septal defect (VSD) resulting from blunt chest injury is a very rare event. The mechanisms of traumatic VSD have been of little concern to dateuntil now, but two dominant theories have been described. In one, the rupture occurs due to acute compression of the heart; in the other, it is due to myocardial infarction of the septum. The clinical symptoms and timing of presentation are variable, so appropriate diagnosis can be difficult or delayed. Closure of traumatic VSD has been based on a combination of heart failure symptoms, hemodynamics, and defect size. Here, we present a case of a 4-year-old boy who presented with a traumatic VSD following a car accident. He showed normal cardiac structure at the time of injury, but after 8 days, his repeated echocardiography revealed a VSD. He was successfully treated by surgical closure of the VSD, and has been doing well up to the present. This report suggests that the clinician should pay great close attention to the patients injured by blunt chest trauma, keeping in mind the possibility of cardiac injury.

가토자궁근(家兎子宮筋)에서 분리(分離)한 Microsome 분획내(分劃內) Adenosinetriphosphatase 활성도(活性度)에 미치는 $Mg^#$, $Ca^#$, $Na^+$, $K^+$ 및 Creatine phosphate의 영향(影響) (The Effect of $Mg^#$, $Ca^#$, $Na^+$, $K^+$ and Creatine Phosphate on the ATPase Activity of Microsomal Fraction from Rabbit Uterus)

  • 최신정
    • 대한약리학회지
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    • 제2권2호
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    • pp.35-42
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    • 1966
  • The author investigated the effect of $Mg^#$, $Ca^#$, $Na^+$, $K^+$ and creatine phosphate on the ATPase activity of microsomal fraction isolated from rabbit uterus and obtained the following results : 1) The uterine microsomal fraction contained the $Na^+-$ and $K^+-$ activated ATPase in the presence of $Mg^#$. The ATPase activity increased with protein content in the fraction. 2) The maximum ATPase activity was obtained at $Na^+$ and $K^+$ concentraction of 100 mM respectively. 3) In the absence of $Mg^#$, the ATPase was not activated by $Na^+$ and $K^+$, but inhibited. 4) Car stimulated the $Na^+-$ and $K^+-$ activated ATPase in the presence of $Mg^#$. However, in the absence of $Mg^#$, the ATPase was not activated by $Ca^#$. 5) The $K^+-$ activated ATPase activity was greater than the $Na^+-activated$ ATPase under all conditions. 6) The $Na^+-$ and $K^+$ activated ATPase activity was increased by addition of creatine phosphokinase and creatine phosphate to the reaction mixture.

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더블허들 모형을 이용한 전통시장 재방문객의 농산물 구입결정 요인에 관한 연구 (A Study on Purchasing Agricultural Products of Re-visitors In Traditional Market Using Double Hurdle Model)

  • 이향미
    • 농촌계획
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    • 제21권2호
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    • pp.137-147
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    • 2015
  • In this study, consumers who have experience of visiting Jeongsun Arirang Market has been selected as samples to understand the characteristics of agricultural products purchase. For this, double hurdle model was used in order to resolve sample selection problem and obtain consistent estimator. The key points are the following. First, as the age increases(up to 59.8 years), chances of purchasing the products at traditional market increase as income increases. Second, when the residence area is outside of Gangwon-province, the purchase amount of the products increased compared to those from visitors within the Gangwon province. Also, visitors who use public transportations purchase less products compared to those who use their own car. Third, probability of agricultural products increase as the visitors consider positive effect the product purchase leads to the local farmers. Fourth, if the visitors consider the quality of the agricultural products, probability of purchasing agricultural product at the site increases. However, if the visitors consider the freshness of the agricultural products, the purchase amount rather drops. Fifth, the probability of purchase increases as visitors consider the brand of traditional market.

가속차로의 길이 제어와 고속도로 접속부 혼잡저감 효과 (Longitudinal Control of Acceleration Lanes and its Impact on Congestion Alleviation)

  • 신치현;김규옥
    • 대한교통학회지
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    • 제23권5호
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    • pp.169-176
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    • 2005
  • 고속도로 합류부의 반복정체는 모든 이의 일상이지만 정체가 발생한 이후에 마땅히 시도할 대책이 없는 것이 작금의 현실이다. 본 연구는 접속부에 혼잡이 발생한 후 상황에 따라 가속차로 길이를 동적으로 제어하여 본선에 대한 상대적인 우월성을 억제함으로써 혼잡구간의 정체를 저감시키는 기법을 제안하고 있다. 가속차로의 동적 제어가 미치는 교통영향 분석을 위해서 car-following 이론에 토대를 둔 미시 모형인 CORSIM을 사용하였으며, 본선의 수요는 LOS D/E로 유지하는 가운데 연결로 수요를 변화시킴으로서 접속부의 혼잡을 점진적으로 연출하고 본선과 가속차로의 운영속도가 역전되는 시점에 가속차로의 유효길이를 축소하는 기능을 구현하였다. 동적 제어의 대상이 되는 가속차로 길이는 세 가지로 제한하였으며 평가척도는 통행시간과 통과교통량으로 하였다. 또 경부고속도로에 신갈 JC서의 유사 운영 결과와 비교를 통해 모의실험 결과를 뒷받침하였다.

고무배합물의 물성을 이용한 레이디얼 타이어의 사이드월 횡강성 계산 (Calculation of Sidewall Lateral Stiffness of a Radial Tire Using Material Properties of Rubber Compounds)

  • 김용우;김종국
    • 대한기계학회논문집A
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    • 제27권10호
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    • pp.1667-1675
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    • 2003
  • This paper has considered the calculation of lateral stiffness of radial tire's sidewall, which consists of cord stiffness and rubber sheet stiffness, by using the material constants of rubber compounds of tire. We have suggested and illustrated how to calculate the rubber sheet lateral stiffness by considering the following aspects. First, the rubber sheet consists of various kinds of rubber compounds with different thickness along the sidewall in the radial direction. Secondly, equivalent Young's modulus of the rubber sheet can be calculated by using available experimental data of rubber compounds. The present method enables us to divide the calculation domain as many as we want, which can reduce numerical error in the calculation of geometrical and mechanical properties. We have illustrated the calculation by using the data of the radial tire for passenger car of P205/60R15.

교통기본도와 운전자 행태에 대한 미시적 분석 (A Microscopic Analysis on the Fundamental Diagram and Driver Behavior)

  • 김태완
    • 한국도로학회논문집
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    • 제14권6호
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    • pp.183-190
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    • 2012
  • PURPOSES : The fundamental diagram provides basic information necessary in the analysis of traffic flow and highway operation. When traffic flow is congested, the density-flow points in the fundamental diagram are widely scattered and move in a stochastic manner. This paper investigates the pattern of density-flow point transitions and identifies car-following behaviors underlying the density-flow transitions. METHODS : From a microscopic analysis of 722 fundamental diagrams of NGSIM data, a total of 20 transition patterns of fundamental diagrams are identified. Prominent features of the transition patterns are explained by the behavior of the leader and follower. RESULTS : It is found out that the average speed and the speed difference between the leader and the follower critically determine the density-flow transition pattern. The density-flow path is very sensitive to the values of vehicle speed and spacing especially at low speed and high density such that most fluctuations in the fundamental diagram in the congested regime is due to the noise of speed and spacing variations. CONCLUSIONS : The result of this study suggests that the average speed, the speed difference between the leader and the follower, and the random variations of speed and spacing are dominant factors that explain the transition patterns of a fundamental diagram.