터널에서 차량의 운행에 의해 생성되는 비정상 유동에 대한 실험적 연구

김정엽,신현준,Kim, Jung-Yup,Shin, Hyun-Joon 한국터널지하공간학회 2009 한국터널지하공간학회논문집 Vol.11 No.4

도로터널내 열유동장의 형성은 여러 가지 요인의 영향을 받는다. 즉 차량의 이동에 의한 피스톤 효과, 환기설비의 환기력, 자연풍 영향, 화재시 부력 등에 따라 도로터널내 기류가 형성된다. 차량의 이동에 의한 피스톤 효과는 도로터널내 기류생성의 일차적인 요인이며, 화재시 연기의 초기 거동에 영향을 줄 수 있다. 본 연구에서는 도로터널내 차량의 이동에 의해 생성되는 비정상 기류를 분석하기 위해서 단순한 형태의 터널과 차량에 대한 축소모형실험장치를 제작하고 실험을 수행하였다. 기본형, 전두부 사변형, 후두부 계단형의 3가지 형태로 차량의 형상을 변화시켜가며 차량운행에 따라 형성되는 터널내 압력과 기류속도를 측정하였다. 실험결과 터털내 생성되는 압력과 속도의 크기는 "기본형>후두부 계단형>전두부 사변형"의 순서로 증가하였다. 실험결과는 향후 3차원 수치해석 결과와의 비교, 검토를 통해서 수치해석 기술의 보완 및 신뢰성 확보를 위한 기초자료로 활용될 수 있다. The thermo-flow field in road tunnel is influenced by some facts such as piston effect of vehicle's move, operation of ventilation facilities, natural wind and buoyancy effect of fire plume. Among those, piston effect is one of primary causes for formation of air flow in road tunnel and has an effect on initial direction of smoke flow in tunnel fire. In this study to analyze the unsteady flow in the tunnel caused by the run of vehicle, the experimental study of vehicle-induced unsteady flow on a reduced-scale model tunnel is presented. While the three types of vehicle shape such as basic type of rectangular shape, diamond-head type and stair-tail type are changed, the pressure and air velocity variations with time are measured. The rising ratio of pressure and velocity are in order of "basic type of rectangular shape > stair-tail type > diamond-head type". The experimental results would be good data for development of a numerical method on the vehicle-induced unsteady tunnel flow.

도로터널 화재발생시 연기유동에 관한 축소모형실험 연구

김정엽,신현준,강세구,안경철,Kim, Jung-Yup,Shin, Hyun-Joon,Kang, Se-Gu,Ahn, Kyung-Chul 한국터널지하공간학회 2004 터널기술 Vol.6 No.2

도로터널내 화재가 발생한 경우 자연환기와 종류식 환기시스템에서의 연기유동에 대한 연구가 수행되었다. Froude Scaling에 기초한 1/18 축적의 축소모형실험장치가 제작되었으며, 화원으로는 연료심지를 이용한 14.55kW 규모의 연소기가 사용되었다. 화원으로부터 등비간격으로 터널천정부근과 수직방향의 온도분포가 측정되었으며, 연소가스의 농도가 피난대피구 입구에서 측정되었다. 연구결과로서 자연환기시스템에서 비상대피구가 225m 간격으로 설치되어 있을 경우 비상대피구 구간의 연기확산시간은 256초가 되며, 20MW의 화재강도에 대해 화염역류를 완전히 방지하기 위해서는 터널풍속을 2.8m/s로 형성해 주어야 한다. In this study, smoke movement in tunnel fire with natural and longitudinal ventilation systems has been investigated. Reduced-scale experiments were carried out under the Froude scaling using 14.55kW fire source with a wick and experimental data is obtained with 1/18 model tunnel test. Temperature profiles were measured under the ceiling and vertical direction along the center of the tunnel and poisonous gas was measured at emergency exit point. The results show that refuge time for 225m intervals of emergency exit in case of natural ventilation systems is 256 seconds and critical velocity for sufficient back-layer prevention is 2.8m/s for fire strength of 20MW.

Sol-gel 법을 이용한 내오염 반사방지 코팅막 제조

김정엽,이지선,황종희,임태영,이미재,현승균,김진호,Kim, Jung-Yup,Lee, Ji-Sun,Hwang, Jonghee,Lim, Tae-Young,Lee, Mi-Jai,Hyun, Soong-Keun,Kim, Jin-Ho 한국재료학회 2014 한국재료학회지 Vol.24 No.12

Anti-reflection coating films have used to increase the transmittance of displays and enhance the efficiency of solar cells. Hydrophobic anti-reflection coating films were fabricated on a glass substrate by sol-gel method. To fabricate an anti-reflection film with a high transmittance, poly ethylene glycol (PEG) was added to tetraethyl orthosilicate (TEOS) solution. The content of PEG was changed from 1 to 4 wt% in order to control the morphology, thickness, and refractive index of the $SiO_2$ thin films. The reflectance and transmittance of both sides of the coated thin film fabricated with PEG 4 wt% solution were 0.3% and 99.4% at 500 nm wavelength. The refractive index and thickness of the thin film were n = 1.29 and d = 105 nm. Fluoro alkyl silane (FAS) was used for hydrophobic treatment on the surface of the anti-reflection thin film. The contact angle was increased from $13.2^{\circ}$ to $113.7^{\circ}$ after hydrophobic treatment.

유압식 이족 휴머노이드 로봇의 경사면 보행 연구

김정엽(Jung-Yup Kim) 제어로봇시스템학회 2012 제어·로봇·시스템학회 논문지 Vol.18 No.3

This paper describes a biped walking algorithm for a hydraulic humanoid robot on inclined floors. To realize stable and robust biped walking, the walking algorithm was divided into five control strategies. The first is a joint position control strategy. This strategy is for tracking desired joint position trajectories with a gain switching. The second is a multi-model based ZMP (Zero Moment Point) control strategy for dynamic balance. The third is a walking pattern flow control strategy for smooth transition from step to step. The fourth is an ankle compliance control, which increases the dynamic stability at the moment of floor contact. The last is an upright pose control strategy for robust walking on an inclined floor. All strategies are based on simple pendulum models and include practical sensory feedback in order to implement the strategies on a physical robot. Finally, the performance of the control strategies are evaluated and verified through dynamic simulations of a hydraulic humanoid on level and inclined floors.

공동주택의 실별 제어환기 도입 타당성 분석

김정엽(Jung-Yup Kim),신현준(Hyun-Joon Shin),권용일(Yong-Il Kwon),윤영우(Young-Woo Yun),조춘식(Chun-Sik Cho) 대한설비공학회 2009 대한설비공학회 학술발표대회논문집 Vol.2009 No.-

Trend of mechanical ventilation system applied to apartment house is introduced and feasibility study on installation of the individual room control ventilation as energy-saving method is carried out through field experiment. While initial cost of installation for the individual room control ventilation increases, the running cost is lower than the individual household control ventilation due to automatic flow rate control and reduction of fan power, and the management cost also decreases due to extension of use life of components. As the results of field experiment on 115㎡-type apartment house, the individual room control ventilation could save the amount of 1,459.5Wh/day when compared with the individual room control ventilation

유지 혈액투석 환자에서 단일풍선 소장내시경으로 치료한 소장출혈

김정엽 ( Jeong Yup Kim ),왕준광 ( Joon Kwang Wang ),김미나 ( Mi Na Kim ),김선철 ( Sun Chul Kim ),김혜원 ( Hye Won Kim ),이영모 ( Young Mo Lee ),권영주 ( Young Joo Kwon ),표희정 ( Heui Jung Pyo ),박자인 ( Ja In Park ),오주연 ( Joo 대한신장학회 2008 Kidney Research and Clinical Practice Vol.27 No.6

Anemia is a common complication of hemodialysis. It reduces the quality of life and is recognized as adverse risk factor. The cause of anemia in CKD (chronic kidney disease) include lack of erythropoietin, gastrointestinal (GI) bleeding, hypothyroidism, hidden infection, and blood loss in hemodialysis. GI bleeding is not unusual complication in patient on maintenance hemodialysis, caused by uremia, medicine (NSAIDS, antiplatelet agents, anticoagulants), angiodysplasia, and ulcer. In CKD patients, GI bleeding is found in various sites over the whole bowel. Small bowel bleeding is one of the most common causes of obscure GI bleeding and constitutes 2-10% of all GI bleeding. Regarding the small bowel bleeding, diagnosis and treatment are much improved recently with the help of wireless capsule endoscopy and double or single balloon enteroscopy. We report a case of GI bleeding due to erosion of small bowel, which was diagnosed and treated with the single-balloon enteroscopy in patients on maintenance hemodialysis.

미세접촉인쇄기법의 설계와 다중스케일해석

김정엽(Jung-Yup Kim),김재현(Jae-Hyun Kim),최병익(Byung-Ik Choi) 대한기계학회 2003 대한기계학회 춘추학술대회 Vol.2003 No.11

Nanometer-sized structures are being applied to many fields including micro/nano electronics,<br/> optoelectronics, quantum computing, biosensors, etc. Micro contact printing is one of the most promising<br/> methods for manufacturing the nanometer-sized structures. The crucial element for the micro contact printing<br/> is the nano-resolution printing technique using polymeric stamps. In this study, a multi-scale analysis scheme<br/> for simulating the micro contact printing process is proposed and some useful analysis results are presented.<br/> Using the slip-link model [1], the dependency of viscoelasticity on molecular weight of polymer stamp is<br/> predicted. Deformation behaviors of polymeric stamps are analyzed using finite element method based upon<br/> the predicted viscoelastic properties.

인간형 로봇 플랫폼 KHR-2 의 설계 및 하드웨어 집성

김정엽(Jung-Yup Kim),박일우(Ill-Woo Park),오준호(Jun-Ho Oh) 대한기계학회 2004 대한기계학회 춘추학술대회 Vol.2004 No.11

In this paper, we present the mechanical, electrical system design and system integration of controllers including sensory devices of the humanoid, KHR-2 (KAIST Humanoid Robot ? 2). We have developed KHR-2 since 2003. Total number of DOF of KHR-2 is 41. Each arm including a hand has 11 DOF and each leg has 6 DOF. Head and trunk also has 6 DOF and 1 DOF respectively. In head, two CCD cameras are used for eye. To control all axes efficiently, distributed control architecture is used to reduce computation burden of main controller and to expand devices easily. So we developed the sub-controller as a servo motor controller and a sensor interfacing devices using microprocessor. The main controller attached its back communicates with sub-controllers in real-time by CAN (Controller Area Network) protocol. We used Windows XP as its OS (Operation System) for fast development of main control program and easy extension of peripheral devices. And RTX HAL extension commercial software is used to realize the real-time control in Windows XP environment.

대상포진 발생 부위에 발생한 분절형 백반증 1예: Isotopic 반응

김정엽 ( Jung Yup Kim ),이윤호 ( Yun Ho Lee ),임재윤 ( Jae Yun Lim ),최주연 ( Ju-yeon Choi ),민준홍 ( Joon Hong Min ),최영준 ( Young Jun Choi ),남재희 ( Jae-hui Nam ),김원석 ( Won-serk Kim ),이가영 ( Ga-young Lee ) 대한피부과학회 2018 대한피부과학회지 Vol.56 No.9

Wolf’s isotopic response is defined as the occurrence of a new skin disorder at the site of another unrelated skin disease that has already healed. In most cases of isotopic response, the initial dermatosis is herpes infection, and the most frequent second dermatoses are granulomatous reactions. Various interpretations of this phenomenon have been attempted. However, the exact mechanism has not been identified yet. Herein, we report a case in which the secondary disease was segmental vitiligo that appeared over the same dermatomes of herpes zoster. A 71-year-old woman presented with well-defined, depigmented patches on the left chest and back. She had been diagnosed with herpes zoster on the same dermatomes and treated with an antiviral agent 3 years ago. Histological examination showed decreased basal melanin pigments and melanocytes. Consequently, the patient was diagnosed with segmental vitiligo based on the clinical and histological findings. (Korean J Dermatol 2018;56(9):543∼547)

급기가압 제연시스템의 방연풍속 형성특성에 대한 수치해석적 분석

김정엽(Jung-Yup Kim),이동호(Dong-Ho Rie),김하영(Ha-Young Kim) 대한설비공학회 2008 대한설비공학회 학술발표대회논문집 Vol.2008 No.2

The fact that the major cases of life casualties are from smoke in the fire accidents and the expected steep increase of skyscrapers, huge spaces, multiplexes and huge scaled underground spaces demand establishment of efficient smoke countermeasure. In pressure differential systems for smoke management, the speed of airflow through open door between accomodation and lobby should be maintained over 0.5m/s on the whole area of door to prevent smoke from infiltrate into evacuation root when the door is open for refuge. The numerical analysis on features of airflow through open door are carried out and the results are presented.