도시철도 차량의 사행동을 고려한 강아치 철도교의 동적응답

정창현(Chang-Hyun Jeong),조국환(Kook-Hwan Cho),신정열(Jeong-Ryol Shin) 한국산학기술학회 2023 한국산학기술학회논문지 Vol.24 No.8

철도교는 열차 축중에 의한 연직하중 분포 외에 열차주행에 따라 크기와 방향이 변하는 횡하중 분포를 나타낸다. 횡하중은 다양한 원인으로 발생하며 각 원인들이 연계하여 복잡한 응답을 나타낸다. 이러한 특성 때문에 설계기준은 교량형식과 무관하게 등가횡하중을 규정하고 있다. 철도교설계는 연직하중에 의한 동적해석을 수행하나 횡하중은 정적해석에 의존하며 횡진동 규정이 미흡하다. 본 연구는 강아치 철도교를 대상으로 사행동의 해석모델을 제시하고 도시철도 차량을 대상으로 교량-열차 상호작용해석을 통하여 정확한 동적응답과 사행동의 효과분석을 연구목적으로 한다. 이를 위하여 열차주행속도에 따라 파장을 매개변수로 선택하였다. 사행의 레일편차, 초기횡력, 위상차, 레일 종방향 마찰계수를 랜덤변수로 가정한 사행동 모델을 제시하고 시간적분법으로 동적응답을 분석하였다. 열차주행속도는 120km/h까지 10km/h 단위로 12가지를 적용하였다. 수치해석결과, 고유진동모드는 1차모드에서 횡변형이 우선적으로 발생하는 횡진동모드가 발생하였다. 거더 중앙부의 횡변위는 사행동을 무시할 경우 0.67mm이나 사행동을 고려하면 주행속도 120km/h에서 최대 4.7mm가 발생되어 약 7배 증가함을 알 수 있다. 이는 등가횡하중에 의한 정적 횡변위 2.4mm의 약 2배에 해당하는 변위이다. 일반적으로 주행속도가 증가하면 사행동을 고려한 횡변위도 증가하는데, 사행동 모델의 파장변화에 따른 횡변위는 특정속도에서 급증한다. 횡변위 응답분포가 급변하는 파장변화와 주행속도는 철도교의 진동특성과 연계되므로 각 교량모델에 따라 사행동 특성을 고려하여야 한다. 특히 횡진동모드가 지배하는 철도교설계는 사행동을 고려한 동적응답을 분석할 필요가 있다. A railway bridge has both a vertical load distribution and a lateral load distribution with size and direction that change according to the train movement. Lateral loads have a variety of causes, and each of them is linked and shows a complex response. Due to these characteristics, design standards stipulate equivalent lateral loads regardless of the type of bridge. In railway bridge design, dynamic analysis is performed based on the vertical load, but static analysis is used for the lateral load, and lateral vibration regulations are insufficient. The purpose of this study is to present a model for the analysis of snake-like motion for a steel-arch railway bridge and to analyze the effects and dynamic responses through bridge/train interaction analysis for urban railway vehicles. To this end, the wavelength was selected as a parameter according to the train speed. A snake-like motion model was made with the rail deviation, initial lateral force, phase difference, and longitudinal friction coefficient of the rail as random variables. The dynamic responses were analyzed using a time integration method. Twelve train speeds of up to 120 km/h were applied with intervals of 10 km/h. In the result of the numerical analysis, the natural vibration mode was lateral, and lateral deformation occurred preferentially in the primary mode. The lateral displacement in the center of a girder was 0.67 mm when the snake-like motion was ignored, but when considering the snake-like motion, up to 4.7 mm of displacement was generated at a speed of 120 km/h, which is an increase by about seven times. This displacement is equivalent to about twice the static lateral displacement of 2.4 mm due to an equivalent lateral load. In general, as the speed increases, the lateral displacement when considering snake-like motion also increases. The lateral displacement according to the wavelength change of the snake-like motion model also increases rapidly at a specific speed. The wavelength change and speed of the rapid change in the lateral displacement response distribution are linked to the behavior characteristics of the railway bridge, so the slope characteristics should be considered for each bridge model. In particular, in railway bridge design dominated by the lateral behavior mode, dynamic responses need to be analyzed while considering snake-like motion.

奇恒之腑(기항지부)와 奇經八脈(기경팔맥)의 관련성 고찰

류정아 ( Jeong Ah Lyu ),정창현 ( Jeong Chang Hyun ) 대한한의학원전학회(구 대한원전의사학회) 2014 대한한의학원전학회지 Vol.27 No.2

Subject : The Association between Extraordinary Organs(奇恒之腑) and Eight Extra Meridians(奇經 八脈). Objectives : This study research some special aspects of Extraordinary Organs and Eight Extra Meridians which differentiated from ordinary Organs and Meridians, and the association between Extraordinary Organs and Eight Extra Meridians. Methods : First, researched classification standard and physiological characteristics of Extraordinary Organs through studying various chapters of HuangdiNeijing. Second, researched The Association between Extraordinary Organs and Eight Extra Meridians through studying on the origin of Eight Extra Meridians in HuangdiNeijing. Third, from accompanying researching the subject of Cheon-gye(天癸) and human body shape, draw synthetic hypothesis on the relationship among ordinary Meridians and Organs, muscles and skins of body shape, Extraordinary Organs and Eight Extra Meridians. Results & Conclusions : The following conclusions could be drawn. 1. Extraordinary Organs afford background for shaping human body. This is same as the properties of the earth which afford background for shaping all creations. The physiological characteristics of Extraordinary Organs is intermediation and regulation between Ki(氣) of Five Viscera & six Bowels and shape of muscles & skins in human body. 2. The origin of Eight Extra Meridians could be found in HuangdiNeijing. The collateral Meridians of the Uterus and Epiglottis Meridian are specifically formulated to supplying for the Uterus or Epiglottis. From this we can draw The Association between Extraordinary Organs and Eight Extra Meridians, that is Eight Extra Meridians are specifically formulated to supplying for Extraordinary Organs. 3. The Cheon-gye(天癸) is doing significant function in Eight Extra Meridians supplying for Extraordinary Organs. Cheon-gye concerned to growth, secondary sexual characters, generative function, aging process. Theses are all concerned with the changing of human body shape. Cheon-gye urge to change the body shape with following the human life cycle. 4. Human body has vertical symmetry because preserve its shape from the gravitational force. Eight Extra Meridians place at the middle or flank axis of human body, thus do physiological function that assistant human body have vertical symmetry shape. The purpose of shaping vertical symmetry is securing space what the inner Twelve Regular Meridians and Five Viscera & six Bowels create there own physical changes. On the other hand the inner changes need deviation between left and right because of mobility and circulation of force. But human body change the shape in the process of growth, reproduction, aging. Eight Extra Meridians play role at time of these processing, thus they deeply concerned to human’s life cycle and reproduction. 5. Eight Extra Meridians and Extraordinary Organs were named ‘Extra’ because of some special aspects which differentiated from ordinary Meridians and Organs. All they play role to have vertical symmetry shape of human body and maintain the shape, thus they deeply concerned to the change of human life cycle. These shaping maintaining and the change of human life cycle are very special aspects of human body. So they needed to differently cognize separate to the ordinary changes of Five Viscera & six Bowels and Twelve Meridians at inner space.

현대(現代) 한국사회(韓國社會)에 적합한 한의학(韓醫學) "치미병(治未病)"방법(方法)에 대한 모색(摸索)

류정아 ( Jeong Ah Lyu ),장우창 ( Woo Chang Jang ),백유상 ( You Sang Baik ),정창현 ( Chang Hyun Jeong ) 대한한의학원전학회(구 대한원전의사학회) 2011 대한한의학원전학회지 Vol.24 No.4

In present-day Korea, a climatic change is causing various changes to the life of people and their body. The climate is more and more warm, so the internal environment of people`s body is exchanging to warm. The climatic change`s range is big and the speed is fast. So the harmony of human body is being destroyed and the human body`s adaptation ability is becoming low. At this condition, diseases more frequently occur. So doctor must expect the occur of diseases and practice early treatment. And in present-day Korea, a life environmental change is being advanced. The life environmental change is causing big changes to the people`s body and having influences to the occur of diseases. To this problem, doctor must expect and practice early treatment. This thesis would like to interpret about present-day Korea`s climatic changes and life environmental changes in Korean Medicine point of view, and try to present the method of Korean Medicine early treatment. And comment on present-day Korea`s early treatment method especially on health supplement or functional food and vaccination.

모래운반선의 창구덮개 면제를 위한 시설기준에 관한 연구

정창현,Jung, Chang-Hyun 해양환경안전학회 2012 해양환경안전학회지 Vol.18 No.5

모래운반선은 호퍼도어를 갖는 경우 제한된 범위내에서 창구덮개의 설치를 면제 받을 수 있으나, 현재 국내에는 호퍼도어를 갖고 있는 선박이 단 한척도 없어 창구덮개를 면제받는 선박이 없는 실정이다. 따라서 모래운반선의 창구덮개 관련 현행 규정의 검토와 사고사례 조사 그리고 현재 운항하고 있는 모래운반선에 대한 설비현황, 복원성능 및 내항성능 평가를 통하여 모래운반선에 대한 창구덮개 면제 조건을 검토하였다. 그 결과, 모래운반선의 경우 창구덮개를 면제 받기 위해서는 화물창의 크기를 조정하여 모래를 화물창 상단부까지 가득 싣더라도 흘수가 만재흘수선을 넘지 않도록 하고, 적절한 풍우밀 조치를 취함으로써 충분한 예비 부력과 복원력 확보가 요구된다. 또한, 배수펌프의 용량은 화물창의 액상상태인 모래를 1시간 이내에 소성상태가 될 수 있도록 배수하기에 충분한 용량이어야 하며, 모든 운항상태에서 작동 가능하여야 한다. 본 연구는 모래운반선의 작업 특성상 창구덮개의 설치작업이 현실적으로 상당히 어렵고, 특히 기상악화시 인명사고로 이어질 수 있는 현실적인 문제점을 항해안전과 관련된 시설기준을 보다 강화함으로써 개선한 것이다. Only the sand carriers fitted with hopper doors can remove their hatch covers in current regulations. However, there is no sand carriers fitted with hopper doors in korea. Through the analysis of accidents, inspection of equipment installed on ships, and evaluation of stability and seakeeping performance concerning the sand carriers, it is expected that the current exemption requirement is modified for hatch covers for sand carriers. As the result, this paper proposed the removal of hatch covers and be fitted by tarpaulin instead to protect water ingress into the holds. This can be done by making the holds smaller designed to be filled full until the top of the hold without exceeding loadline. Also, the bilge pumps should have the sufficient capacity of pumping water out in the early stage of sand-water mixture to wetted condition in approximately 1 hour and be operationally ready in every voyage conditions.

실선 예항시험을 통한 예인선의 소요마력 산출에 관한 연구

정창현,남택근,최혁진,Jung, Chang-Hyun,Nam, Taek-Kun,Choi, Hyuek-Jin 해양환경안전학회 2014 海洋環境安全學會誌 Vol.20 No.4

사고선박의 2차적인 피해를 줄이기 위해서는 사고선박을 안전한 곳으로 이동시키기 위한 예인선의 소요마력 산출이 요구되며, 길이 93 m 여객선형 대상선박에 대한 실선실험을 통하여 소요마력 산출에 대한 이론적인 계산식의 유효성을 검증하였다. 실선실험 결과는 이론계산 결과와 비교해 볼 때 상당히 일치되어 예선의 소요마력 산정을 위해 사용하기에 충분하다고 판단되며, 정적저항에서 공기저항, 마찰저항, 잉여저항과 더불어 프로펠러 고착저항이 상대적으로 큰 값으로 평가되었다. 피예인선은 예인과정에서 좌우 측면으로 $30^{\circ}$정도까지 스윙운동 및 요우잉이 발생하였으며, 이로 인한 동적저항이 큰 값으로 평가되었다. 추후 안전율에 대한 연구가 필요할 것으로 판단되며, 저항의 정확한 예측을 통하여 안전율을 최소화함으로써 경제적인 예인선의 사용이 가능할 것으로 판단된다. It needed the calculation of the required tugboat's power to move the damaged vessel to the safe area for reducing the additional damages. In this paper, it was verified the theoretical calculation method on the required power of tugboat through the 93m real ship tests. From the experiments, it was considered that the theoretical calculation method was sufficient to estimate the required power of tugboat. The resistance of the locked propeller was relatively big portions compared with other static resistances such as air resistance, frictional resistance and residual resistance. And dynamic resistance induced by swing movement and yawing was continuously occurred and it also was great effects on the total resistance. In the future, the safety factor will be considered and the exact prediction of ship's resistance will enhance the efficiency of tugboat because of the minimization of safety factor.

생체모방형 물고기 로봇 ‘익투스’의 동적 해석을 위한 DOE를 이용한 입력파라미터 최적화

정창현(Chang-Hyun Chung),이상효(Sang-Hyo Lee),김경식(Kyoung-Sik Kim),차유성(You-Sung Cha),류영선(Young-Sun Ryuh) 제어로봇시스템학회 2010 제어·로봇·시스템학회 논문지 Vol.16 No.8

Recently, there is a rising interest on studying bio-inspired robotic fish because of real fish’s great maneuverability and high energy efficiency. However, the researches about the robotic fish have not been done so much and there are still lots of problems to use them in the real environment such as in the river. This paper describes a bio-inspired robotic fish ‘Ichthus’ which is developed in KITECH and has 3 DOF propulsive mechanism. We develop the dynamic motion equation of ‘Ichthus’ in the underwater environment and analyze response characteristics of ‘Ichthus’ according to the input parameters of tail fin’s amplitude and oscillation frequency. Then we propose control parameters at the various velocities. These parameters are useful to increase energy efficiency and it can be used when the fish robot moves in the real environment, for example, we can propose proper amplitude and oscillation frequency when the fish robot passes through the narrow space between obstacles.

스마트워크 시스템 성공을 위한 사용자 만족의 영향요인에 대한 연구 : P그룹사를 중심으로

정창현,황찬규,홍순근,Jung, Chang Hyun,Hwang, Chan-Gyu,Hong, Soon-Geun 한국데이터전략학회 2013 Journal of information technology applications & m Vol.20 No.3

At the center of the repeating evolution of IT industry, there is mobile computing in the ubiquitous environment, and the increasing usage of smart phones contribute more to its growth. P corporation co-developed with Google and implemented smart work system called SWP for the purpose of 'communication and collaboration with co-workers' beyond the general goal of increasing productivity and comfort of employees. The primary objective of this study is to objectively analyze the influence of the effect factor from end user's perspective and user satisfaction on SWP usage, intention for continuous usage and individual performance. To accomplish this research purpose, this study established research models and hypothesis by collective review about information system success models, and tested the research hypotheses using the structural equation modeling technique by data collected from 320 SWP system users of P corporation. Variations for system satisfaction evaluation standard are 1)SW system usage 2) intention for continuous usage 3) individual performance, effect variations are 1) social factors 2) technical factors 3) combination of social and technical factors. Therefore, this study is about influence factors on success of SWP system and how the factors impact the outcome. The test results of this research model is summarized as follows. Firstly, system user's satisfaction had positive impact on all three; SWP system usage, intention for continuous usage and individual performance. Secondly, social factor 'SWP control system' and technical factor 'information quality' and 'system quality' had positive impact on SWP system user satisfaction, while social factor 'shared value' and technical factor 'service quality' did not have significant effect on user satisfaction. Shared value however, had interactive effect with 'information quality' and 'service quality'. This study is expected to contribute to spread of academic research on smart work system by suggesting a model that can show important factors for corporation while explaining the successful implementation of SWP and its continuous usage.

뇌졸중 쥐 모델에서 인간 제대혈 유래 중간엽줄기세포의 치료 효과 연구

정창현 ( Chang Hyun Jeong ),임정연 ( Jung Yeon Lim ),박상인 ( Sang In Park ),김성묵 ( Seong Muk Kim ),전진애 ( Jin Ae Jun ),오원일 ( Won Il Oh ),이재권 ( Jae Kwon Lee ),전신수 ( Shin Soo Jeun ) 한국조직공학과 재생의학회 2006 조직공학과 재생의학 Vol.3 No.4

Mesenchymal stem cells(MSCs) have the ability to differentiate into multiple cell types. It has been reported that MSCs ameliorate functional deficits after transplantation into various neurologic disease models. In this study, to demonstrate the effect of human umbilical cord blood-derived MSCs(hUCB-MSCs) on stroke models, we transplanted the PKH-26 labeled hUCB-MSCs into the contralateral region of injured rat brain at 7 days after injury, and then examined the behavioral test, migration ability of transplanted hUCB-MSCs to injury site, and differentiation potentiality of transplanted hUCB-MSCs into neural cells. The results were: (1) a behavioral test(adhesive- removal and rotarod test) showed a significant improvement in the MSCs transplanted group as compared to the PBS injected group, (2) PKH-26 labeled MSCs were detected in the boundary zone of injured site at 4 weeks after transplantation, and (3) a few of transplanted MSCs exhibited a labeling for mature neural linage markers NeuN and GFAP. We suggest that hUCB-MSCs could be an effective cell source for treating ischemic brain injury.

논문(論文) : 『소문(素問),골공론(骨空論)』의 “병소음지경(幷少陰之經)에 대한 고찰(考察)”

정창현 ( Chang Hyun Jeong ) 대한한의학원전학회 ( 구 대한원전의사학회 ) 2008 대한한의학원전학회지 Vol.21 No.1

논문(論文) : 『의방합편(醫方合編)』에 대한 연구

정창현 ( Chang Hyun Jeong ),김용주 ( Yong Joo Kim ),장우창 ( Woo Chang Jang ) 대한한의학원전학회 ( 구 대한원전의사학회 ) 2008 대한한의학원전학회지 Vol.21 No.1