골프 드라이버 비거리가 타수에 미치는 영향에 대한 종단적자료 분석

김성일(Sung Il Kim),김진욱(Jin Uk Kim) 한국사회체육학회 2014 한국사회체육학회지 Vol.0 No.57

The purpose of this study was to analyze the longitudinal effect of driving distance on scoring average in PGA tour. For this study, data were taken from official PGA Tour web site. They were longitudinal data over 33 years(1980-2012) since driving distance and scoring average have been measured repeatedly every year. Ranks of the player were considered as subjects. A linear mixed model was applied to the data to estimate cross-sectional as well as longitudinal effect of driving distance on scoring average. The estimates of the linear mixed model showed that there was a difference between cross-sectional and longitudinal effect. Therefore, if we use the ordinary least squares of regression analysis to get the effect of driving distance on scoring average, we would have wrong information about the relationship. From the longitudinal effect it can be concluded that scoring average has decreased about .73 significantly as driving distance has increased 33.27 yards longitudinally.

초고속 주행환경에서의 종단경사 설계기준에 관한 기초연구

송민태,강호근,김흥래,이의준,신준수,김종원 한국도로학회 2013 한국도로학회논문집 Vol.15 No.4

PURPOSES: The purpose of this study theoretically reviews vertical grade deriving process in super high speed environment and compares overseas design criteria with Domestic Standardization also draws suitable vertical grade design criteria of high standard for Domestic Circumstances in Korea. METHODS : By researching domestic vehicle registration status, calculating typical vehicle, using Vissim which is traffic simulation program, Speed-distance curve of the vehicle is derived under each design speed condition. Through Speed-distance curve, estimating critical length of grade and considering critical length of grade, maximum longitudinal incline is proposed. RESULTS : The result of domestic vehicle registration status, the typical vehicle for deriving vertical grade is calculated based on gravity horsepower ratio 200 lb/hp. For calculating critical length of grade, according to change speed of uphill entry, speed-distance curve is derived by using Vissim. Critical length of grade is calculated based on design speed 20 km/h criteria which is point of retardation. Estimated critical length of grade is 808 m and based on this result, maximum longitudinal incline was confirmed in the design speed between 130km/h to 140km/h. CONCLUSIONS: The case of the typical vehicle(truck) which is gravity horsepower ratio 200 lb/hp, maximum longitudinal incline 2% is desirable at the super high speed environment in the design speed between 130km/h to 140km/h.

탐진강수계 고도 및 하구로부터 거리에 따른 어류구성 및 분포특성

문운기 ( Woon Ki Moon ),배대열 ( Dae Yeul Bae ),서진원 ( Jin Won Seo ),안광국 ( Kwang Guk An ) 한국물환경학회 2012 한국물환경학회지 Vol.28 No.4

This study is focused on fish fauna and distributional features along with physical gradients and stream orders in the Tamjin River basin, Korea. Fish sampling and investigation were conducted for 2 years from 2009 to 2010, Total number of fish species collected were 47 species of 16 family, The group of cyprinidae was mostly abundant, Both fish abundance and biotic index were declined with increasing altitude and longitudinal distance from the river mouth. Two species of Zacco temminckii and Pungtungia herzi were prevalent in most of sampling sites and showed no altitudinal and longitudinal differences. Most other species, however, were spatially restricted to specific regional altitudes. Several species including Zacco platypus, Squalidus gracilis majimae and P, herzi were broadly distributed from river mouth to 50 km, Eight species including Z, temminckii and Rhynchocypris oxycephalus only appeared in over 10 km from the river mouth. Both Odontobutis platycephala and Pseudobagrus koreanus were classified as upstream dewelling species observed only in over 30 km from the river mouth, High proportion of tolerant and omnivorous species were more dominated in the downstream zone of the dam, whereas intolerant and insectivorous species were abundant in the upstream zone of the dam. The variable of stream order showed positive relationship between number of fish species and total individuals collected. Sensitive species including insectivore had a declining tendency with increasing stream order, while tolerant specie including omnivore species had relatively increased with stream order. Overall, our study suggested that fish distribution considerably depends on altitudinal gradient and longitudinal distance from the river mouth as well as physical habitat.

Vehicle Tests of a Longitudinal Control Law for Application to Stop-and-Go Cruise Control

Moon, Ilki,Yi, Kyongsu The Korean Society of Mechanical Engineers 2002 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.16 No.9

This paper presents the implementation and vehicle tests of a vehicle longitudinal control scheme for Stop and Go cruise control. The control scheme consists of a vehicle-to-vehicle distance control algorithm and throttle/brake control algorithm for acceleration tracking. The desired acceleration of a vehicle for vehicle-to-vehicle distance control has been designed using Linear Quadratic optimal control theory. Performance of the control algorithm has been investigated via vehicle tests. A millimeter wave radar sensor has been used for distance measurement. A stepper motor and an electronic vacuum booster have been used for throttle/brake actuators, respectively. It has been shown that the proposed control algorithm can provide satisfactory performance.

도로터널에서의 화재환기 설계에 관한 연구

김명배,최준석,한용식,최병일 사단법인 한국터널지하공간학회 2004 한국터널지하공간학회논문집 Vol.6 No.2

The several assumptions and design parameters to determine the ventilation rate in tunnel ventilation system were examined. In longitudinal ventilating tunnel, the ventilation rate has been determined by the critical velocity above which the smoke propagation to the upstream of ventilating air is prevented. Based upon the examination of assumptions and experimental results, we suggested the improved method to determine the critical velocity. In transverse ventilating tunnel, we found that the ventilation rate has been determined in accordance with the custom rather than fire-smoke dynamics such as the critical velocity in the longitudinal ventilating tunnel. It is because the ventilation rate in the transverse ventilation system has been determined by considering only the ventilation of contaminant by vehicle. To improve the ventilation design parameters based upon the fire-smoke dynamics, we conducted model tunnel fire experiments. From the experimental results, smoke propagating distance and smoke filling were suggested as the design parameter to determine the ventilation rate in transverse ventilating tunnel. And tunnels in Europe designed by the custom is found to have the dangerous nature in view of fire safety. 터널의 환기설계에 관련하여 종류식과 횡류식의 환기용량의 산정을 위해서 필요한 제반 가정들을 검토하였고, 종류식 설계에서의 최종 값인 임계유속 산정을 위한 몇 가지의 공식을 분석하였다. 이를 토대로 특정 공식을 개선하기 위한 방안을 실험결과를 토대로 제시하였다. 횡류식 설계에서 국제적으로 사용되고 있는 용량산정에 관한 지침은 화재공학적 의미가 전혀 없으며 관행적으로 적용되어 온 것임을 알 수 있었다. 뿐만 아니라 기존의 횡류식 환기설계에는 설계개념조차 명확하지 않음을 입증하였다. 즉 횡류식 시스템에서는 종류식에서의 “연기의 역류 방지를 위한 최소 유속의 유지” 라는 개념조차 없이 환기용량이 결정되어 왔으며, 이것은 터널의 화재환기가 오염물질의 환기로부터 시작되어 정확한 화재공학적 분석이 결여되었기 때문이다. 이러한 문제를 해결하기 위한 시도로 횡류식 환기의 설계개념으로서 연기전파거리와 연기축적을 제안하였다. 축소모델 터널을 이용하여 연기전파거리에 관한 실험결과를 제시하였고, 이를 이용하여 기존의 관행대로 설계된 유럽의 터널들에 적용하였을 때 안전성에 문제가 있음을 보였다.

터널 굴진면 수평변위와 천단변위를 이용한 단층대 예측방법의 비교ㆍ분석

윤현석 ( Hyun-seok Yun ),서용석 ( Yong-seok Seo ) 대한지질공학회 2016 지질공학 Vol.26 No.3

3차원 수치해석을 통해 획득한 터널 굴진면에서의 수평변위와 천단부에서의 변위 특성을 이용하여 굴진면 전방의 단층대 예측 가능 거리를 비교·분석하였다. 굴진면의 수평변위는 천단부에서 가장 근접한 지점의 변위를 이용하였으며, 천단부의 변위특성을 이용한 단층대 예측방법은 천단침하의 경향선과, L/C (천단부의 축방향 변위/천단침하) 비, C/C₀ (천단침하/평균 천단침하) 비를 이용하였다. 단층이 터널의 굴진방향과 이루는 각도와 경사가 서로 다른 총 28개의 단층 모델을 분석한 결과, 순방향의 경사를 가지는 터널은 L/C 비와 C/C₀ 비를 이용한 방법에서 가장 빨리 단층을 예측할 수 있는 것으로 나타났다. 또한 역방향 경사를 가지는 터널은 L/C 비와 수평변위를 이용한 방법이 굴진면 전방의 단층을 빨리 예측할 수 있는 것으로 나타났다. 결과적으로 굴진면 전방의 단층대를 예측하기 위해 이용된 수평변위와 천단침하의 경향선, L/C 비, C/C₀ 비는 대부분의 단층 모델에서 예측이 가능하였고, 굴진면으로부터 일정한 거리와 시간이 경과된 후에 변위 측정이 가능한 일상계측의 단점을 고려할때 굴착과 동시에 계측을 수행할 수 있는 수평변위를 이용하는 방법이 대안이 될 것으로 판단된다. A three-dimensional finite element analysis was conducted to analyze the predictable distances of a fault zone by using longitudinal displacement on tunnel face, trend line, L/C ratio, and C/C₀ ratio at tunnel crown. The analysis used 28 numerical models with various fault attitudes. As a result, those faults that have drives with dip could be predicted earliest in L/C and C/C₀ ratio analysis. And those faults that have drives against dip could be predicted earliest in L/C ratio and longitudinal displacement anal-ysis. In addition, the fault zone ahead of tunnel was predicted in most models by using longitudinal displacement, trend line, L/C ratio, and C/C₀ ratio. However, the longitudinal displacement among these methods may be most usefully predict a fault zone since it is displacements can be measured immediately after tunnel excavation.

지리정보시스템(Geographic Information System)을 사회과학에 활용하는 방안에 대한 연구

이상윤 한국사회학회 2013 한국사회학회 사회학대회 논문집 Vol.2013 No.6

지리 정보시스템이 다양한 사회과학연구에 유용함에도 불구하고 아직까지는 사회과학연구(특히 도시사회학 분야)에 크게 활용되지 못하는 실정이다.따라서 본 연구는 지리정보시스템을 사회과학 연구에 이용 할 수 있는 많은 방법들중에 세 가지 실용적인 방법을 소개 하고자 한다. 첫째, 관심포인트 주변의 지리적 여건을 보다 정확하게 고찰할 수 있고, 둘째, 정적(longitudinal) 비교가 불가능한 자료를 가능하게 할 수 있고, 셋째, 공간을 하나의 변수로 만들 수 있는 방법이다. 위의 방법이 사회과학연구에 있어서 공간적 중요성을 크게 부각시킬 수 있을 뿐 아니라 공간을 보다 정확하게 개념화를 시켜서 통계모형에 적용이 가능하다고 하겠다. Although the Graphical Information System(GIS) has proven to be a useful tool in conducting social science research, it has not been widely used in many research endeavors especially in the field of urban sociology. Therefor, this study examines three ways to use GIS in social science research. First, GIS enables researchers to estimate impacts from a specific point of interest on people living in adjacent area. Second, GIS also enables researchers to conduct longitudinal analyses by using census data. Third, GIS finally enables researchers to convert spatial elements into variables included in statistical models. Those approaches can advance social science theories by enhancing understandings of relationships between people and space where they are in.

근접 항해하는 선박의 상호작용과 충돌시간 계산에 관한 연구

이춘기(Chun-Ki Lee),윤점동(Jeom-Dong Yoon),강일권(Il-Kwon Kang) 한국항해항만학회 2006 한국항해항만학회지 Vol.30 No.5

항내 혹은 협수로와 같은 제한수역에서 근접하여 항해중인 두 선박간의 상호 유체력 및 모멘트가 선박조종운동에 상당히 크게 영향을 준다는 것은 잘 알려져 있다. 두 선박간의 상호간섭력은 종방향 거리,횡방향 거리 및 두 선박의 속도의 함수로서 가정될 수 있다. 본 연구에서는 근접 항해중인 추월선박과 피 추월선박간의 상호유체력을 계산하고,두 선박간의 횡방향 및 종방향 거리와 속도, 그리고 타 사용으로 인한 접근 상황 및 충돌시간에 대해서 검토, 고찰하였다. It is well known that the ship manoeuvring motion is greatly affected by hydrodynamic forces and moments acting between two vessels passing too close to each other in confined waters, such as in a harbour or narrow channel. This interaction between two vessels could be assumed to be the functions of the longitudinal distance, transverse distance and their speeds. The aim of this study is to calculate the interaction between two vessels passing close to each other on parallel courses by simulation, and to estìmate the effect of rudder action and time of collision through simulation under the condition of various longitudinal distances and different speed-ratios of the two vessels.

차세대 고속철의 증속을 고려한 PSC 철도교 마찰 교량받침의 동적 거동 해석

오순택,이성태 한국구조물진단유지관리공학회 2023 한국구조물진단유지관리공학회 논문집 Vol.27 No.6

이 연구에서는 차세대 고속철의 증가하는 주행속도에 따라 600 km/h 까지 10 km/h 간격으로 고속철 PSC 박스 연속교량의 교량받침에 대한 동적거동을 수치해석하였다. 경부 고속철 구간의 40미터 단경간과 2경간 연속 PSC 박스교를 연구대상으로 프레임모형을 구성하였으며, 38자유도의 관성질량 차량모형 및 교량과 궤도의 불규칙성을 포함한 상호작용력을 고려하였다. 주행속도별 교량받침의 종방향 변위와누적이동거리와 변위속도를 산정하여 교량의 동적거동 추이분석과 비교하였다. 또한 마찰판의 내구성능평가를 위한 장기마찰시험 기준을 적용하였다. In this study, the dynamic behavior of friction bearings of PSC (Pre-Stressed Concrete) box train continuous bridge was numerically analyzed at 10 km/h intervals up to 600 km/h according to the increasing speed of the next-generation high-speed train. A frame model was generated targeting the 40-meter single-span and two-span continuous PSC box bridges in the Gyeongbu High-Speed Railway section. The interaction forces including the inertial mass vehicle model with 38 degrees of freedom and the irregularities of the bridge and track were considered. It was calculated the longitudinal displacement, cumulative sliding distance and displacement speed of the bridge bearings at each running speed so that compared with the dynamic behavior trend analysis of the bridge. In addition, long-term friction test standards were applied to evaluate the durability of friction plates.

근접 항해하는 선박의 상호작용과 충돌시간 계산에 관한 연구

이춘기(Chun-Ki Lee),윤점동(Jeom-Dong Yoon),강일권(Il-Kwon Kang) 한국항해항만학회 2006 한국항해항만학회 학술대회논문집 Vol.1 No.-

항내 혹은 협수로와 같은 제한수역에서 근접하여 항해중인 두 선박간의 상호 유체력 및 모멘트가 선박조종운동에 상당히 크게 영향을 준다는 것은 잘 알려져 있다. 두 선박간의 상호간섭력은 종방향 거리, 횡방향 거리 및 두선박의 속도의 함수로서 가정 될 수 있다. 본 연구에서는 근접 항해중인 추월선박과 피 추월선박간의 상호유체력을 계산하고, 두 선박간의 횡방향 및 종방향 거리와 속도, 그리고 타 사용으로 인한 접근상황 및 충돌시간에 대해서 검토, 고찰하였다. It is well known that the ship manoeuvring motion is greatly affected by hydrodynamic forces and moments acting between two vessels passing too close to each other in confined water, such as in a harbour or narrow channel. This interaction between two vessels could be assumed to be the functions of the longitudinal distance, transverse distance and their speeds. The aim of this study is to calculate the interaction between two vessels passing close to each other on parallel courses by simulation, and to estimate the effect of rudder action and time of collision through simulation under the condition of various longitudinal distances and different speed-ratios of the two vessels.