장거리 터널 내 고속 운송체의 유동 해석을 위한 1-3차원 혼합격자 기법개발

최중근(Joong-Keun Choi),김태경(Tae-Kyung Kim),권혁빈(Hyeok-Bin Kwon),김규홍(Kyu-Hong Kim) 한국철도학회 2011 한국철도학회 학술발표대회논문집 Vol.2011 No.10

본 논문은 장거리 터널 내에서 운송체의 고속운행에 의해 발생한 유동을 해석하기 위한 격자 기법 개 발에 관한 내용이다. 수십 km의 터널 시스템을 3차원으로 해석하기 위해서는 많은 수의 격자가 요구된 다. 그러나 전체 터널 시스템을 3차원으로 계산한다는 것은 비효율적이다. 그리하여 본 논문에서 계산의 효율성을 위해 터널 내 유동장에 영향을 크게 주는 달리는 운송체 주위 정거장과 환기구는 3차원으로 격자를 구성하였고 그 외의 직전 터널 구간은 1차원 격자로 구성하였다. 터널 내의 유동은 열차가 달릴 때 생성되는 열차 주위의 유동에 의해 결정된다. 그러므로 열차 주위에는 격자를 조밀하게 생성시켜 주었다. 그리고 이 격자는 열차가 이동할 때 함께 움직이도록 하여 격자의 질을 유지하게 하였다. 열차의 운행 속도는 가속 등속 감속의 3단계로 구분하였다. 이와 같은 장거리 터널 내 비정상 고속 운송체 유 동을 해석하기 위해 상용 소프트웨어인 Ansys vr. 12.0의 UDFs(User-Defined Functions) 기능을 사용하였다. This paper shows development of 1-3 dimensional hybrid mesh method to analysis flow induced by ultra-high speed vehicle inside a long distance tunnel. For three-dimensional analysis of the tunnel system many meshes are required. However it is not efficient to calculate the whole tunnel system in three-dimension. Therefore in this paper three-dimension meshes was used to describe stations shafts and around vehicle and one-dimension meshes was used to describe the tunnel except these three sections. And unsteady flow analysis of the ultra-high speed vehicle was performed with UDFs in commercial software Ansys vr. 12.0.

환기구가 지하터널에서 열차에 발생하는 압력파에 미치는 영향

최중근(Joong Keun Choi),정성민(Seung Min Jeong),최원석(Won Seok Choi),김규홍(Kyu Hong Kim) 대한기계학회 2014 대한기계학회 춘추학술대회 Vol.2014 No.5-2

대심도 터널 내부에서 주행하는 열차의 속도증가에 따른 차량 내부압력 변화

최중근(Joong-Keun Choi),정성민(Seong-Min Jeong),김규홍(Kyu-Hong Kim) 한국철도학회 2013 한국철도학회 학술발표대회논문집 Vol.2013 No.11

최고 시속 200 km로 운행될 대심도 급행철도와 같이 터널 내에서 열차가 고속으로 주행할 경우 승객의 이명감에 대한 고려가 설계과정에 반영되어야 할 것으로 보인다. 이명감은 차량 내부압력 변화와 연관되어 있으므로 현재 지하철의 사양에 고속철도의 기밀도 기준을 적용하여 열차 속도증가에 따른 내부압력 변화를 전산유체역학으로 해석하였다. 해석결과가 국내의 객실 내 압력변화 규정을 만족시키는지 차량 내부압력 변화를 분석해 보니 규정을 만족시키지 못하는 것을 확인하였다. 그래서 지하철의 무딘전두부 형상을 유선형 형상으로 변경하여 내부압력 변화를 해석해 보았다. 형상 변화를 통해 내부압력 변화가 규정을 만족시키는 것을 확인할 수 있었다. 대심도 급행철도 차량의 설계 시 차량 내부압력 변화 규정을 만족시키도록 적절한 전두부 형상과 차량의 기밀도를 선정하여야 할 것으로 보인다. The Great Train eXpress (GTX) is a new high-speed subway travelling at 200 km/h in tunnels. Therefore, before the construction of the GTX, the aural discomfort should be evaluated for passenger comfort. The aural discomfort is related to the pressure change inside the train. Therefore, the pressure changes according to an increase in speed of the train are simulated using Computational Fluid Dynamics (CFD). For the simulations, the data of the present subway train and the sealing time constant of the highspeed train are applied. When the results of the simulation are analyzed, the safety criterion isn’t satisfied. To satisfy the safety criterion, the nose is changed from a blunt shape to a streamlined shape. After changing the nose, the safety criterion is satisfied. The GTX should be designed by considering the nose shape and the sealing time constant properly for passenger comfort.

외식소비자의 소비트렌드에 관한 연구

최중근(Choi Joong-Keun) 국제관광산업학회 2009 국제관광산업연구 Vol.2 No.4

Owing to improved living standards and changing dietary lifestyle. dining away from home becomes a part of our daily life beyond any special event held together with special people on a special day. 1n th e above context. the purpose of this study is to make a conceptual examination into food service consumers and their trends. and investigate the latest trends of Korean food service consumers in practice as well. Korean food service industry has a tendency toward specialization and seg mentation owing to various conceptual menus and restaurants developed to l1leet the needs and expectations of food service consumers. And this study focuses primari1y on fusion cuisine, ethnic cuisine, well - being cuisine and slow food to investigate the latest trends of food service consumers. As a result, it is found that these trends emerge and prevail in reflection of social atmospheres and consumer needs. In addition, it is found that respective trends are closely associated with one another. For instance. fusion cuisines have been developed to satisfy needs of consumers who pursue something new in din ing. In yearning for unknown world, there is a variety of ethnic foods introduced from the 3rd world (e.g. East Asia, Central and South America, Africa and some regions of Southeast Asia) into Korean food service consumers. Interestingly, these trends still evolve in a grand category of well - being lifestyle and develop even as a slow food campaign all over the world. In order that these dining trends can be settled as contemporary ones beyond simple temporary social fashion, it will be necessary for consumers to take open l11 ind-set to understand real meanings of Major trends and accept them even as a part of contemporary culture beyond a simple curiosity and pursuit to some thing new. Furthermore, it will be also necessary for consumers to change their minds to consider environment as well as better quality of ind individual life.

대심도 급행철도의 속도 증가와 전두부 형상변화에 따른 공력저항 분석

최중근(Joong-Keun Choi),김태경(Tae-Kyung Kim),정성민(Seong-Min Jeong),김규홍(Kyu-Hong Kim) 한국철도학회 2013 한국철도학회 학술발표대회논문집 Vol.2013 No.5

논문은 대심도 급행철도와 관련하여 수행된 기초 연구에 대한 것이다. 대심도 급행철도는 지하정차역이 있는 도시철도의 특성을 가지고 있다. 그러므로 현재의 도시철도의 제원을 바탕으로 공력저항 해석을 수행하였다. 열차의 속도를 증가시킨 해석과 전두부 형상을 변화시킨 해석을 수행하였으며 이 결과들을 비교하고 분석하였다. 그 결과로 현재 도시철도 형상으로 속도를 증가시킬 경우 압력항력이 상당히 증가한다는 것을 확인하였다. 압력항력 증가의 원인은 무딘 전두부 형상에 있고 이를 유선형으로 변경할 경우 압력항력이 현저하게 줄어든다는 것을 확인하였다. 그리고 전두부 형상변화가 점성저항에는 큰 영향을 미치지 않았다. In this paper, we deal with the basic study related to aerodynamic drag of underground high-speed train. The underground high-speed train also has the characteristic of the subway system with stations. Therefore, we simulate the system using the subway system data. Additional simulations about fast velocity and long nose shape are performed. The results are compared with the simulation result of the present subway system and analyzed. The analysis shows that nose shape is important to reduce aerodynamic drag in the tunnel and the streamlined nose shape doesn’t affect viscous drag but causes the significant decrease of pressure drag.

지하철 터널에서 열차의 속도증가에 따른 승강장 스크린 도어의 풍압 평가

최중근(Choi Joong-Keun),정성민(Jeung Seong-Min),최원석(Choi Won-Seok),김규홍(Kim Kyu-Hong) 대한기계학회 2013 대한기계학회 춘추학술대회 Vol.2013 No.12

The Great Train eXpress (GTX) is a high-speed subway travelling at 200 km/h in tunnels. The speed of the GTX is faster than the speed of the present subway. Therefore, because of an increase speed of the train, the pressure load on platform screen doors would be increased. The pressure loads are evaluated for the design of platform screen doors(PSD) using Computational Fluid Dynamics (CFD). The pressure load of the train travelling in 100 km/h is compared with the pressure load of the train travelling in 200 km/h. And the pressure loads are evaluated by changing the length of the train nose and the cross-sectional area of the tunnel.

전십자인대 재건술 후 고식적 재활과 적극적 재활의 결과

이병일,민경대,최중근,유재응,손치수,Lee, Byung-Ill,Min, Kyung-Dae,Choi, Joong-Keun,You, Jae-Eung,Son, Chi-Soo 대한관절경학회 1997 대한관절경학회지 Vol.1 No.1

The purpose of this study is to compare the results between conventional and accelerated rehabilitation program following ACL reconstruction using bone-patellar tendon-bone. Conventional rehabilitation focused on protecting the new ligament by blocking terminal extension and avoiding active quadriceps function in the terminal degrees of extension. But there is current trend toward early postoperative mobilization and intensive. so called 'accelerated', rehabilitation stressing hyperextension of the knee. The results of intraarticular ACL reconstruction with conventional and accelerated rehabilitation were prospectively compared for one year postoperatively in a series of 27 patients. Range of motion and thigh circumference were checked preoperatively, and weekly up to 8 weeks, 3 months. 6 months, and 1 year postoperatively. Stress radiologic test, KT-1000 arthrometer. Cybex II dynamometer were checked in preoperatively, and 3 months, 6 months, and 1 year postoperatively. There were no differences of objective stability and restoration of muscle power. But the accelerated group had a low incidence of extension loss. excellent range of motion, and less difference of thigh circumference. We concluded that accelerated rehabilitation program is recommendable due to superiority in terms of range of motion, especially less extension loss without increasing laxity of knee joint.

Active Air Flap을 장착한 차량의 주행저항 및 엔진룸 유동해석

김태경(Tae-Kyung Kim),최중근(Joong-Keun Choi),김정현(Jung-Hyun Kim),조준호(Jun-Ho Cho),이영빈(Yeong-Bin Lee),김규홍(Kyu-Hong Kim),이동호(Dong-Ho Lee),김진필(Jin-Phil Kim),이준호(Jun-Ho Lee) 한국자동차공학회 2012 한국자동차공학회 부문종합 학술대회 Vol.2012 No.5

This paper describes on numerical studies on improvement of car engine room and aerodynamic drag for CO2 reduction with an active air flap. The numerical models were full scaled car of YF SONATA that has detailed car engine room with active air flaps. An base model of YF SONATA was compared with a change grill model of that which has active air flaps. As a result, the aerodynamic drags were compared depending on the operating conditions and times of active air flap on upper and under grill. An engine room cooling efficiency which were internal temperature, static pressure and stream line was shown according to those flap conditions.

외식상품의 마케팅전략방안 연구

이무형(Lee, Mu-Houng),최중근(Choi, Joong-Keun) 국제관광산업학회 2010 국제관광산업연구 Vol.2 No.3

Marketing starting from business economics encompasses the industries and objects where exchange occurs as its scope. Food service industry is not an exception to this. Food service is performed after customers’ payment and its series of follow-up processes. The experiences of receiving food service and their positive or negative results determine success or failure of food service companies. Nowadays, food service consumers basically believe that taste of food should be maintained and they demand and expect more than that. These may include atmosphere, facilities, services, etc. distinguished from the other food service companies. Among them, as initial interior design and regular changes, atmosphere and facilities are also the products that customers indirectly feel. Meanwhile, services are the products that customers feel directly. That is, food service consumers feel value satisfaction through physical environments and services. In such food service industries, consumers keep changing what they want and demand new products and innovative services that they have not felt before. Therefore, the marketing of food service companies should cope with the market changes and can predict the factors affecting such changes. In this way, food service companies should establish right marketing strategies by finding out the attributes of customer preference and choice to survive the rapidly changing market. In addition, they should establish their marketing strategies corresponding to the market, by accurately figuring out the resources and products that they possess. The food products established based on such market situations and factors are a necessity to the growth of food service companies, along with the satisfaction of changing customers’ demand and needs. Therefore, this study is aimed to suggest the methods of developing marketing strategies for food service products, after establishing the concepts and types of marketing strategies through previous and relevant national and international research and literature, in order to achieve the objectives of “methods of marketing strategies for food service products.”

종골 골내 결절종 - 증례 보고 -

민경대,고은석,김병흠,최중근,신병준,이병일,Min, Kyung-Dae,Koh, Eun-Suk,Kim, Byung-Heum,Choi, Joong-Keun,Shin, Byung-Joon,Lee, Byung-Ill 대한족부족관절학회 2001 대한족부족관절학회지 Vol.5 No.2

Intraosseus ganglion cysts are uncommon, benign, juxta-articular and usually found within long bones. A 35-year-old male presented with acute right ankle pain. He denied any traumatic event. Tenderness was localized on the subtalar joint. Radiologic studies demonstrated a cystic lesion in the juxta-articular portion of the posterior facet of the calcaneus. The patient underwent excision and curettage. Postoperative recovery was uneventful. A histological examination confirmed a typical intraosseus ganglion cyst. A case of an intraosseus ganglion cyst of the calcaneus causing acute subtalar joint pain is described.