차로분리시설 개발을 위한 소형차 승월 방지 높이 검토에 관한 연구

노민형,박재홍,윤덕근,성정곤 한국도로학회 2021 한국도로학회논문집 Vol.23 No.6

PURPOSES : According to the guidelines of Super Bus Rapid Transit(BRT), dedicated bus roads and dedicated bus lanes shall be used, and physical lane separation facilities should be installed for lane separation. Therefore, physical barriers (lane separation facilities) are being developed for exclusive bus operations. Low-profile lane separation facilities should be developed that do not interfere with the views of pedestrians and drivers. The appropriate heights of the barrier to prevent overriding in the event of passenger car crashes were reviewed. METHODS : By applying the performance standards of the safety barrier, passenger protection performance according to the change in the height of the lane separation facilities and the vehicle behavior after the crash were analyzed using computer crash simulations. Crash criteria of 1.3 ton-60 km/h-20°and 1.3 ton-80 km/h-20°were used as vehicle impact conditions. The simulation was performed by increasing the height of the lane separation facilities from 200 mm to 500 mm. To prevent the deformation of the lane separation facilities owing to a vehicle crash, the boundary conditions of the node under the lane separation facilities were fixed and modeled. RESULTS : The collision simulation results showed that, for a collision speed of 60 km/h, no override occurred for the height of the lane separation facility of 250 mm or more, and for a collision speed of 80 km/h, no override occurred for the height of the lane separation facility of 300 mm or more. CONCLUSIONS : Therefore, the appropriate height of the lane separation facility for the collision of a passenger car with a collision speed of 80 km/h or less was determined to be 300 mm or more.

차로분리시설의 대형차 충돌 시 전도 방지 높이에 관한 연구

노민형,박재홍,윤덕근,성정곤 한국도로학회 2021 한국도로학회지 Vol.23 No.3

PURPOSES : The percentage of vehicle overturning accidents is 16.3% of vehicle alone fatal accidents, with a fatality rate of 9.0%, accounting for a high proportion, and heavy vehicles with a high center of gravity are vulnerable to overturning accidents. In the standard guidelines of Super-Bus Rapid Transit(S-BRT), it is recommended to install physical facilities that separate buses from other traffic on dedicated bus ways, and lane separation facilities are being developed. To develop low-profile lane separation facilities that do not interfere with sight obstruction for pedestrians and drivers, it is necessary to review the height of lane separation facilities to prevent overturning crashes of heavy vehicles. METHODS : Heavy vehicle impact conditions of 8ton-55km/h-15°, 8ton-55km/h-20°, 8ton-65km/h-15°, and 8ton-65km/h-20°were applied to compare the vehicle behavior by the height of lane separation facilities using LS-DYNA, a three-dimensional nonlinear impact analysis program based on speed and angle changes. In addition, the behavior of the vehicle after the collision was analyzed to examine the impact conditions in which an overturning crash occurs when a heavy vehicle collides with a low-profile lane separation facility and the appropriate height of the facility to prevent overturning. RESULTS : In general, under the 8ton-65km/h-15°condition, which is a heavy vehicle impact condition used in the performance standard of the barrier, the vehicle’s behavior after the collision was stable as the height of the lane separation facility increased. CONCLUSIONS : Therefore, when the impact conditions were 8ton-65km/h-15°or less, it was determined that the appropriate height to prevent the condition of the lane separation facility was 400mm or more.

다양한 환경에 적용 가능한 충격흡수시설의 시뮬레이션 분석 및 실물충돌시험 결과 분석

노민형,박재홍,서창원,성정곤,윤덕근 대한토목학회 2022 대한토목학회논문집 Vol.42 No.3

Energy absorption facilities installed on roads should follow the performance standards of the real-car crash test of ‘Installation and Maintenance Guidelines for Roadside Safety Facilities’. However, due to different installation conditions, such as differing structure widths on roads, some energy absorption facilities do not provide adequate performance. In order to apply varied environments on roads, an energy absorption structure was designed in this study with 150 mm height and four layers of W-shape guardrail at 200 mm intervals, and the performance was verified using LS-DYNA computer simulation. Through a real-car crash test, the performance ofthe facility designed by LS-DYNA was tested and was found to meet the performance of the CC2 category for crash cushions. The conclusion of the comparison demonstrates that the simulation and the real-car crash tests are both significant. 도로안전시설 설치 및 관리 지침 차량방호 안전시설 편에서 충격흡수시설은 실물충돌시험을 통해 성능 기준을 만족하는 제품만을 현장에 설치하도록 하고 있다. 그러나 기존의 설치된 충격흡수시설의 경우 설치 환경에 따라 방호해야할 구조물과의 폭 차이로 인하여 방호성능을 발휘하지 못하는 문제점이 있다. 이에 본 연구에서는 다양한 환경에 적용하기 위하여 높이 150 mm의 W형 가드레일을 200 mm 간격으로 4단 배치하는 충격흡수시설을 LS-DYNA 컴퓨터 시뮬레이션을 이용하여 개발하고 실물충돌시험을 통하여 성능 기준을 검증하였다. 시뮬레이션을 통해 개발한 충격흡수시설이 CC2등급의 성능 기준을 만족한다는 것을 실물충돌시험으로 확인하였고 시뮬레이션 결과와 실물충돌시험 결과를 비교 분석하여 충돌 시뮬레이션의 결과가 유의미하다는 것을 확인하였다.

감충성능을 갖는 슬라이딩 지주의 에너지흡수장치 개발

노민형,장대영,이성수,한기장 대한토목학회 2020 대한토목학회논문집 Vol.40 No.5

Non-breakaway crashworthy sliding posts move rigidly with a vehicle in the early stage of vehicle impact. During this stage, a vehicle imparts its linear momentum to the post, experiencing first-stage speed loss followed by second-stage loss from the crush of the energy-absorbing pipe (EAP) installed under the guide rail. An EAP is the key element of a crashworthy sliding post and should be confined to the post foundation. This paper covers the development of an EAP for a sliding post of 507 kg, which is a sliding post type frequently used in Korea for cantilever signs. Detailed explanations of the designs for an EAP structure using LS-DYNA impact simulation are given, and the crashworthiness of the systems are confirmed through crash tests. The EAP presented in this paper can accommodate impacts from 0.9 ton—60 km/h to 1.3 ton—80 km/h, and is applicable to foundations up to 2.7 m in length. 차량과 충돌 시 분리되지 않는 감충형 슬라이딩 지주는 충돌 초기에 차량과 일체로 되어 강체운동을 한다. 이때 차량의 선형모멘텀이 지주에 전달되면서 차량의 1차 감속을 이루고 이어서 가이드레일 아래에 설치된 Energy-Absorbing Pipe (EAP)가 찌그러지면서 나머지 충돌에너지를 흡수하여 2차 감속을 이룬다. 따라서 EAP는 슬라이딩 지주의 핵심요소이고 그 크기는 지주기초 안에 설치될 수 있어야 한다. 본 논문은 국내 편지식 표지판에 많이 사용되는 지주와 베이스구조를 합하여 총 507 kg의 무게를 갖는 감충형 슬라이딩 지주에 사용하기 위한 EAP의 개발에 관한 것이다. LS-DYNA프로그램을 이용한 충돌해석을 통하여 EAP구조를 설계하고 실차충돌실험을 통하여 감충성능을 평가하는 과정을 상세히 설명하였다. 본 연구를 통하여 제시된 EAP는 최소 0.9 ton-60 km/h에서 최대 1.3 ton-80 km/h 충돌에 대한 감충성능을 발휘하고 기초길이가 2.7 m 이하로 제약될 때 활용될 수 있다.

노인 발열 환자에 있어 전산화단층촬영 진행과 응급실 재내원과의 상관 관계

노민형,조준호,범진호,한은아 대한응급의학회 2021 대한응급의학회지 Vol.32 No.4

Objective: The number of elderly people visiting emergency rooms is rapidly increasing. Fever is one of the common complaints of patients who come to the emergency room, and it is often difficult to determine its cause in elderly patients only through basic examinations and tests. This study sought to verify the relationship between computed tomography and emergency department revisits of febrile elderly patients. Methods: This study is a retrospective medical record analysis study. Patients who came to our emergency room between September 2016 and September 2019, aged 65 years or more, and with body temperature higher than 37.8 C at the time of presentation or during their stay in the emergency room were enrolled. Patient age, sex, vital signs at triage, laboratory tests, whether computed tomography (CT) was conducted or not were analyzed. The primary outcome was set as revisits to the emergency department within 72 hours after discharge, due to any reason. Results: Three thousand two hundred and forty patients were enrolled and of these 289 patients revisited the emergency department (ED). In the revisit (-) group, CT was performed on 44.09% of patients and 54.67% of patients in the revisit (+) group thus showing a statically significant difference. Conclusion: This study showed that in elderly patients with fever presenting to the ED, patients who underwent a CT had 1.558 higher odds of revisit to the ED compared to patients who did not undergo a CT. From this result, it should be considered that the decision to discharge the febrile elderly patients based on the results of CT examination may not be appropriate.

차로분리시설 개발을 위한 소형차 승월 방지 높이 검토에 관한 연구

노민형,박재홍,윤덕근,성정곤 한국도로학회 2021 도로 : 도로학회지 Vol.23 No.3

PURPOSES : According to the guidelines of Super Bus Rapid Transit(BRT), dedicated bus roads and dedicated bus lanes shall be used, and physical lane separation facilities should be installed for lane separation. Therefore, physical barriers (lane separation facilities) are being developed for exclusive bus operations. Low-profile lane separation facilities should be developed that do not interfere with the views of pedestrians and drivers. The appropriate heights of the barrier to prevent overriding in the event of passenger car crashes were reviewed. METHODS : By applying the performance standards of the safety barrier, passenger protection performance according to the change in the height of the lane separation facilities and the vehicle behavior after the crash were analyzed using computer crash simulations. Crash criteria of 1.3 ton-60 km/h-20°and 1.3 ton-80 km/h-20°were used as vehicle impact conditions. The simulation was performed by increasing the height of the lane separation facilities from 200 mm to 500 mm. To prevent the deformation of the lane separation facilities owing to a vehicle crash, the boundary conditions of the node under the lane separation facilities were fixed and modeled. RESULTS : The collision simulation results showed that, for a collision speed of 60 km/h, no override occurred for the height of the lane separation facility of 250 mm or more, and for a collision speed of 80 km/h, no override occurred for the height of the lane separation facility of 300 mm or more. CONCLUSIONS : Therefore, the appropriate height of the lane separation facility for the collision of a passenger car with a collision speed of 80 km/h or less was determined to be 300 mm or more.

차로분리시설의 대형차 충돌 시 전도 방지 높이에 관한 연구

노민형,박재홍,윤덕근,성정곤 한국도로학회 2021 한국도로학회논문집 Vol.23 No.6

PURPOSES : The percentage of vehicle overturning accidents is 16.3% of vehicle alone fatal accidents, with a fatality rate of 9.0%, accounting for a high proportion, and heavy vehicles with a high center of gravity are vulnerable to overturning accidents. In the standard guidelines of Super-Bus Rapid Transit(S-BRT), it is recommended to install physical facilities that separate buses from other traffic on dedicated bus ways, and lane separation facilities are being developed. To develop low-profile lane separation facilities that do not interfere with sight obstruction for pedestrians and drivers, it is necessary to review the height of lane separation facilities to prevent overturning crashes of heavy vehicles. METHODS : Heavy vehicle impact conditions of 8ton-55km/h-15°, 8ton-55km/h-20°, 8ton-65km/h-15°, and 8ton-65km/h-20°were applied to compare the vehicle behavior by the height of lane separation facilities using LS-DYNA, a three-dimensional nonlinear impact analysis program based on speed and angle changes. In addition, the behavior of the vehicle after the collision was analyzed to examine the impact conditions in which an overturning crash occurs when a heavy vehicle collides with a low-profile lane separation facility and the appropriate height of the facility to prevent overturning. RESULTS : In general, under the 8ton-65km/h-15°condition, which is a heavy vehicle impact condition used in the performance standard of the barrier, the vehicle’s behavior after the collision was stable as the height of the lane separation facility increased. CONCLUSIONS : Therefore, when the impact conditions were 8ton-65km/h-15°or less, it was determined that the appropriate height to prevent the condition of the lane separation facility was 400mm or more.

차로분리시설 충돌 시 탑승자 안전지수 및 충돌 후 차량의 거동에 관한 연구

노민형,박재홍,윤덕근,성정곤 한국도로학회 2022 한국도로학회논문집 Vol.24 No.5

PURPOSES : The "Super-Bus Rapid Transit" (S-BRT) standard guidelines recommend installing physical facilities to separate bus lanes, so as to remove possible conflicts with other traffic when using an existing road as an S-BRT route. Based on a collision simulation, we reviewed the protective performance and installation method of a low-profile barrier, i.e., one that does not occupy much of the width of the road as a physical facility and does not obstruct the driver's vision. METHODS : The LS-DYNA collision analysis software was used to model the low-profile barrier, and a small car collision simulation was performed with two different installation methods and by changing the collision speeds of the vehicle. The installation methods were divided into a fixed installation method based on on-site construction and a precast method, and collision speeds of 80 and 100 km/h were applied. The weight of the crash vehicle was 1.3 tons, and the segment lengths of the low-profile barriers were 2.5 and 4.0 m, respectively. The lowprofile barriers were modeled as precast concrete blocks, and the collision simulation for a fixed concrete barrier was performed by fixing the nodes at the bottom of the low-profile barrier. The low-profile barrier comprised a square cross-section reinforced concrete structure, and the segments were connected by connecting steel pipes with varying diameters to wire ropes. RESULTS : From comparing and analyzing the small car collision simulations for the changes in collision speeds and installation methods of the low-profile barrier, a significant difference was found in the theoretical head impact velocity (THIV) and acceleration severity index(ASI) for the 2.5-m barrier at a collision speed of 80 km/h. However, the differences in the installation method were not significant for the 4.0-m barrier. The occupant safety index with a collision speed of 80 km/h was calculated to be below the limit regardless of the installation method, and the length of the segment satisfied the occupant protection performance. At a collision speed of 100 km/h, when the segment length of the 2.5-m barrier was fixed, the THIV value exceeded the limit value; thus, the occupant protection performance was not satisfied, and the occupant safety index differed depending on the installation method. The maximum rotation angle of the vehicle, which reflects the behavior of the vehicle after the collision, also varied depending on the installation method, and was generally small in the case of precast concrete. CONCLUSIONS : Low-profile barriers can be installed using a fixed or precast method, but as a result of the simulation, the precast movable barrier shows better results in terms of passenger safety. Therefore, it would be advantageous to secure protection performance by installing a low-profile barrier with the precast method for increased safety in high-speed vehicle collisions.

응급실에서 의사소통 할 때 투명마스크의 사용 효과

노민형 ( Noh Minhyung ),한은아 ( Han Eunah ),조아라 ( Cho Ara ),조준호 ( Cho Junho ) 대한의료커뮤니케이션학회 2020 의료커뮤니케이션 Vol.15 No.2

Background: It is important to communicate accurately in the emergency department. Due to COVID-19 pandemic, a mask is mandatory to protect medical staffs and patients from infectious diseases, and the mask is known to disturb speech intelligibility. The objective of this study is to find out if a transparent mask can affect communication. Methods : We conducted a randomized pre- and post-test trial with 40 participants in a real emergency room environment. The reader puts on a mask and read aloud sentences which are frequently used between medical staffs and patients or among medical staffs. The type of mask was randomly assigned to the reader which was transparent or non-transparent. Frequently used 5 sentences between medical staffs and patients and 5 sentences among medical staffs from prepared 100 sentences were randomly selected and recited. Participants were told to write down the sentences they heard. Each sentence written down was graded 0 or 1. After writing down 10 sentences, reader puts on another type of mask and the same experiment was done. The order of transparent/non-transparent mask was randomly allocated to each participant. Results : In frequently used sentences between medical staffs and patient, average score with a transparent mask was 4.88, and with a non-transparent mask was 4.50(p=0.001). In frequently used sentences among medical staffs, average score with a transparent was 4.77, and with a non-transparent mask was 4.05(p<0.001). Conclusions: This study showed the transparent mask improves speech intelligibility when communicating in an emergency room.

다양한 환경에 적용 가능한 충격흡수시설의 시뮬레이션 분석 및 실물충돌시험 결과 분석

노민형(No, Min Hyung),박재홍(Park, Jea Hong),서창원(Seo, Chang Won),김정우(Kim, Jung Woo),윤덕근(Yun, Duk Geun) 대한토목학회 2021 대한토목학회 학술대회 Vol.2021 No.10