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Jeong, Eunbi,Oh, Cheol,Lee, Seolyoung Elsevier 2017 ACCIDENT ANALYSIS AND PREVENTION Vol.104 No.-
<P><B>Abstract</B></P> <P>Automated driving systems (ADSs) are expected to prevent traffic accidents caused by driver carelessness on freeways. There is no doubt regarding this safety benefit if all vehicles in the transportation system were equipped with ADSs; however, it is implausible to expect that ADSs will reach 100% market penetration rate (MPR) in the near future. Therefore, the following question arises: ‘Can ADSs, which consider only situations in the vicinity of an equipped vehicle, really contribute to a significant reduction in traffic accidents?’ To address this issue, the interactions between equipped and unequipped vehicles must be investigated, which is the purpose of this study. This study evaluated traffic safety at different MPRs based on a proposed index to represent the overall rear-end crash risk of the traffic stream. Two approaches were evaluated for adjusting longitudinal vehicle maneuvers: vehicle safety-based maneuvering (VSM), which considers the crash risk of an equipped vehicle and its neighboring vehicles, and traffic safety-based maneuvering (TSM), which considers the overall crash risk in the traffic stream. TSM assumes that traffic operational agencies are able to monitor all the vehicles and to intervene in vehicle maneuvering. An optimization process, which attempts to obtain vehicle maneuvering control parameters to minimize the overall crash risk, is integrated into the proposed evaluation framework. The main purpose of employing the optimization process for vehicle maneuvering in this study is to identify opportunities to improve traffic safety through effective traffic management rather than developing a vehicle control algorithm that can be implemented in practice. The microscopic traffic simulator VISSIM was used to simulate the freeway traffic stream and to conduct systematic evaluations based on the proposed methodology. Both TSM and VSM achieved significant reductions in the potential for rear-end crashes. However, TSM obtained much greater reductions when the MPR was greater than 50%. This study should inspire transportation researchers and engineers to develop effective traffic operations strategies for automated driving environments.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A simulation evaluation framework to identify optimal vehicle control parameters to enhance traffic safety was proposed. </LI> <LI> An external application program interfacewas used to implement a genetic algorithm (GA) based optimization in VISSIM simulations. </LI> <LI> Results imply that the traffic operation strategiesare important for traffic safety in automated driving environment. </LI> </UL> </P>
Jeong, Eunbi,Oh, Cheol,Lee, Gunwoo,Cho, Hanseon U.S. National Research Council, Transportation Res 2014 Transportation Research Record Vol.2424 No.-
<P> Driver inattentiveness is one of the critical factors that contribute to vehicle crashes. The intervehicle safety warning information system (ISWS) is a technology to enhance driver attentiveness by providing warning messages about upcoming hazards under the connected vehicle environments. A novel feature of the proposed ISWS is its capability to detect hazardous driving events, which are defined as moving hazards with a high potential to cause crashes. The study presented in this paper evaluated the potential effectiveness of the ISWS to reduce crashes and to mitigate traffic congestion. The study included a field experiment that documented actual vehicle maneuvering patterns of accelerations and lane changes, which were used to enhance the realism of simulation evaluations. Probe vehicles equipped with customized onboard units, which consisted of a GPS device, accelerometer, and gyro sensor, were used. A microscopic simulator, VISSIM, was used to simulate a driver’s responsive behavior after warning messages were delivered. A surrogate safety assessment model was used to derive surrogate safety measures to evaluate the effectiveness of ISWS in terms of traffic safety. The results showed a reduced number of rear-end conflicts when the ISWS’s market penetration rate (MPR) and the congestion level of the traffic conditions increased. The reduced number of rear-end conflicts was approximately 84.3%, with a 100% MPR under Level of Service D traffic conditions. Analysis of the standard deviation of speed showed that a reduction of 39.9% was achieved. The outcomes of this study could be valuable to derive smarter operational strategies for ISWS. </P>
열차 출도착 데이터와 교통카드 데이터를 활용한 도시철도 역사 시설물 서비스수준 추정 방안 연구
정은비(Eunbi Jeong),이인묵(Inmook Lee),유소영(Soyoung Iris You),김경태(Kyeongtae Kim) 한국도시철도학회 2019 한국도시철도학회논문집 Vol.7 No.1
본 연구에서는 대중교통 체계의 대표 거점인 도시철도 역사에 대한 데이터 기반의 보행 서비스 수준 추정 방안에 대한 연구를 수행하였다. 이용객 기반의 교통카드 실적 데이터와 실시간 열차 운영정보인 열차 출‧도착 데이터를 분석에 활용하였다. 노선별 특성, 이용객 특성 등을 고려하여 구로디지털단지역, 한양대역, 잠실역을 대상으로 분석을 수행하였으며, 분석자료 구축, 데이터 연계성 검토, 이동성 분석의 3단계 과정을 통해 도시철도 역사 보행 서비스수준 추정 가능성을 제시하였다. 분석 결과, 열차 하차 이용객 수가 증가할수록 열차 이용객의 이동성이 감소하는 것으로 나타나, 실적기반 데이터를 이용한 도시철도 역사 보행 서비스수준의 추정 가능성이 존재함을 확인하였다. 본 연구에서 제시한 방법론은 기존 시뮬레이션 분석, 현장조사 및 설문조사 외에 데이터 기반의 보행 서비스 수준 분석을 위한 기초 자료로 활용이 가능하며, 이를 통해 보다 신뢰성 있고 현실적인 도시철도 역사 서비스 평가가 가능해 질 것으로 기대된다. This study proposed the methodology for estimating the pedestrian level of service for metro station based on data. In this study, smart card data and real-time train arrival and departure data were used for analysis. Guro Digital Complex station, Hanyang University station, and Jamsil station were selected as the target station in consideration of the characteristics of line information, users, etc. The methodology for estimating the level of service procedure proposed in this study comprises three steps: data construction, data connectivity check, mobility analysis. According to the result of the relationship between the number of getting off passengers and mobility index, as the number of getting off passengers increases, the mobility of the passengers decreases. Through the results, it is identified that there is a possibility of estimating the pedestrian level of service based data. The proposed data-based methodology would be contribute to the more reliable and realistic metro station service assessment.
Laparoscopic management of periurethral leiomyoma
( Eunbi Kim ),( Joong Sub Choi ),( Jae Man Bae ),( Won Moo Lee ),( Un Suk Jung ),( Jeong Min Eom ) 대한산부인과학회 2019 대한산부인과학회 학술대회 Vol.105 No.-
Objective: Present an unusual case Target: Adanced practicioners Methods: Background and Aims: To investigate the feasibility of laparoscopic myomectomy in case of periurethral leiomyoma. Methods: Design: Case study. Patients: A 40-year-old Korean woman presented with 6cm sized palpable mass bulging the anterior vaginal wall. Interventions: Laparoscopy. Results: A 40-year-old Korean woman had a laparoscopic periurethral myomectomy on July, 04, 2019. Her preoperative MRI showed a tumor originating from the dorsal and left lateral part of the urethra and developing in the vesicouterine space and vesicovaginal septum. A laparoscopic approach with development of the vesicouterine space permitted a safe exposition of the myoma. After the bladder and vaginal wall had been completely freed, further dissection was conducted with isolation of the distal cranio-dorsal portion of the urethra. The dissection plane with the vaginal wall was developed up to the caudal margin of the urethral myoma and total excision of the myoma was performed. Conclusion: Our experience indicates that laparoscopic management of periurethral leiomyomas that develop into the vesicouterine space and vesicovaginal septum is feasible and safe.