• Journal of the Korean Data and Information Science Society
• /
• 제19권2호
• /
• pp.463-473
• /
• 2008

In this study, we measure damage depth and calculate effective impact speed in case of rear-end collision using real car insurance data. We study the relationship between demage depth and effective impact speed, and present statistical model for these two variables. In our real data study, 3-degree polynomial equation model is better fit to effective impact speed and demage depth than the simple linear model that are estimated in previous other studies. Damage depth is a major factor to see the extent of impact in a car collision, and by using this equation, it is possible to evaluate the severity of driver's injury.

• 한국항해항만학회지
• /
• 제47권4호
• /
• pp.202-211
• /
• 2023

국내 해양사고에서 어선의 충돌사고는 타 선종보다 빈번하고 사고 심각도는 높은 편에 속한다. 과거 큰 피해를 불러온 국내 어선충돌사고의 시사점은 어선이 충돌 직전까지 높은 항행 속력을 유지하고 있었다는 것과 어선이 규모 차이가 큰 선박과 충돌하였다는 점에 있다. 본 논문에서는 어선의 충돌사고 결과로 나타나는 선박피해 심각도를 선박의 속력과 분석하여 상관관계를 확인하는 연구를 하였다. 이를위해 도로교통분야에서 활용되고 있는 유효충돌속도(Effective Impact Speed)라는 개념을 두 선박의 충돌상황에 적용하였고 2016년부터 2022년까지 해양사고 재결서 중 어선과 어선, 어선과 비어선 충돌사고 데이터를 수집하여 총 617척 선박의 유효충돌속도를 산출하였다. 분석된 데이터를 바탕으로 유효충돌속도를 독립변수, 선박피해 심각도를 종속변수로 하는 이항 및 다항 로지스틱 회귀분석을 수행하여 두 변수의 상관성을 살펴보았다. 분석결과 유효충돌속도와 선박피해 심각도가 서로 통계적으로 유의하다는 것과 선박피해심각도는 유효충돌속도와 함께 선박의 질량에도 큰 영향을 받는다는 것을 확인할 수 있었다.

• 한국인터넷방송통신학회논문지
• /
• 제15권4호
• /
• pp.239-247
• /
• 2015

최근에 자동차 사고발생 빈도수가 높은 정면충돌사고와 추돌사고에 대해 사회적 관심도 높아지면서 다양한 연구들이 진행되고 있다. 본 연구에서는 자동차 충돌사고에서 재구성을 위한 유효충돌속도와 인체상해발생정도의 관계를 과학적으로 분석하여 관련 모형식을 제시하였으며, 인체상해가 가능한 자동차 실차실험의 한계가 명확하므로 이를 대신하여 각종 충돌실험자료와 인체실험자료 등을 심층 분석하고자 하였다. 그 결과로 정면 및 추돌사고의 경우에는 유효 충돌속도가 7 km/h 이하에서는 상해가 발생하지 않는 임계치를 나타냈으며, 충돌속도와 소성변형량 정도를 통해 상해정도가 유효충돌속도에 선형적으로 비례하는 모형식을 제시하였다. 따라서 본 연구를 통하여 새롭게 제시된 유효충돌속도와 상해발생정도의 추정모형은 사고재구성에서 최소한의 공학적 판단기준으로 활용 가능하여 법적 분쟁시 유익한 정보를 제공할 것으로 사료된다.

• International Journal of Railway
• /
• 제2권1호
• /
• pp.1-7
• /
• 2009

The development of structural solutions for high-speed or very high-speed tracks that minimize total life cycle costs of the system is a key issue to improve the operational profitability of new investments. In opposition to conventional ballasted tracks, slab track solutions can be a cost-effective solution, but only in the cases where the benefits due to the increase in track availability and the reduction of track maintenance offsets its much higher construction costs. In the cases where such investment is not feasible, it is worth to evaluate possible structural improvements to ballasted track that allow reducing its maintenance needs without increasing too much its construction costs. This paper evaluates the design requirements and the impact of improving conventional high-speed ballasted tracks by using a bituminous subballast layer. It is divided into two main parts: first the design requirements of the structural solutions with bituminous subballast and its possible benefits on high-speed track deterioration, and secondly the evaluation of the economic impact, in terms of construction costs, of using this structural solution material in future Spanish high-speed lines.

• 한국산학기술학회논문지
• /
• 제22권1호
• /
• pp.402-408
• /
• 2021

기계 설계를 기반으로 제작한 자동차에 의한 사고 발생 시 차량 공학적인 분석은 심도 있게 조사하지 않고 조사자의 주관적인 경험 지식을 토대로 분석하는 경우가 있다. 본 연구는 실제 발생한 중앙선 침범 사고 자료를 토대로 캐드(CAD) 프로그램을 이용하여 현장 상황을 도면화하고, 도면화 한 자료를 시뮬레이션 프로그램(PC-Crash)에 적용하여 250번의 충돌 상황을 반복적으로 수행하여 최종 정지 위치 및 최종 정지 자세와 부합하는 충돌 속도, 진행 자세, 조향 작동 여부 및 제동 여부 등의 상관 관계를 분석했다. 충돌 속도가 낮을수록 이탈각의 영향을 크게 받지 않고 속도가 높은 차량의 속도에 영향을 크게 받고 충돌 이후에는 유효 충돌 속도와 같이 속도가 낮은 차량은 높아지고, 속도가 높은 차량은 낮아진다. 본 연구의 시뮬레이션 결과는 마이티가 중앙선을 넘은 자세로 오르막 좌커브 구간을 진행하다가 마주오던 포터를 인지하고 자기 진행 차로로 복귀하는 과정과 포터의 전면 좌측면이 충돌하여 포터가 우대각선 방향으로 밀려나 전면이 약 11시 방향을 향해 최종 정지하는 것을 규명하였다.

• 한국전산유체공학회지
• /
• 제4권1호
• /
• pp.1-7
• /
• 1999

The numerical methodology for computing tile impact forces and water entry behaviors of high speed water entry bodies was been developed. Since the present method assumed the impact occurs within a very short time interval. the viscous effects do not have enough time to play a significant role in the impact forces, that is, the flow around a water-entry object was assumed as an incompressible potential flow and is solved by the source panel method. The elements fully submerged into the water are routinely treated, but the elements intersected by the effective planar free surface are redefined and reorganized to be amenable to the source panel method. To validate the present code, it was applied to disk, cone and ogive model and compared with experimental data. Good agreement was obtained. The water entry behavior such as the bouncing phenomena from the free surface was also simulated using the impact forces and two degree of freedom dynamic equation. Physically acceptable results were obtained.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 1998년도 추계 학술대회논문집
• /
• pp.167-174
• /
• 1998

The numerical methodology for simulating water entry behaviors of the high-speed bodies has been developed. Since the present method assumed the impact occurs within a very short time interval, the viscous effects do not have enough time to play a significant role in the impact forces, that is, the flow around a water-entry object was assumed as an incompressible potential flow and is solved by the source panel method. The elements fully submerged into the water are routinely teated, but the elements intersected by the effective planar free surface are redefined and reorganized to be amenable to the source panel method. To validate the present code, it has been applied to the ogive model and compared with experimental data. Good agreement has been obtained. The water entry behavior of the bouncing phenomena from the free surface has been also simulated using the impact forces and two degree of freedom dynamic equation. Physically, acceptable results have been obtained.

• 대한조선학회 특별논문집
• /
• 대한조선학회 2015년도 특별논문집
• /
• pp.28-33
• /
• 2015

Speed log measurement has always been of utmost importance to the mariners. To date the most accurate maritime speed measurement comes from Doppler measurement, where speed may be measured relative to either water(speed through water) or seabed(speed over ground). Recently, a clarification has been issued by the International Maritime Organization (IMO) regarding the speed measuring devices, which could ultimately impact the final arrangement of these devices for ships being constructed after July 1, 2014. This paper will discuss the clarification in depth and necessary action which shall be taken by the owners and operators of the ships impacted.

• 한국운동역학회지
• /
• 제15권3호
• /
• pp.153-159
• /
• 2005

The purpose of this study was to investigate the Effective X-Factor in golf swing. The term X-Factor means the relative rotation of shoulders with respect to hips during the golf swing. To ascertain the Effective X-Factor that resulted in a high club head speed at impact six golfers' swing motions were videotaped and analyzed using three-dimensional techniques. The results can be summarized as follows. The standard deviations of the professionals' average club head speeds were higher than the amateurs'. This means that the professionals' swing skills were better than amateurs' in driving accuracy and consistency. As the club head speeds were increased gradually the X-Factors and the club head speeds had reached to the subjects' average club head speeds, but the X-Factors and the club head speeds were not increased above the subjects' average club head speeds. The X-Factor Stretch early in the down swing was existed and Professional stretched values were higher than the amateurs. In conclusion my research results suggested that the increase in Effective X-Factors had no relationship to the increase in club head speeds.

• 복식문화연구
• /
• 제32권1호
• /
• pp.58-69
• /
• 2024

The purpose of this study was to develop the Functional golf inner-wear by preventing the injuries and enhancing the performance of the Golf swing by checking the influence of the wearing of the functional golf inner-wear considering golf characteristics on the Swing trajectory and Shot distance. Functional inner-wear effective for golf swing was manufactured using the sports taping method. Changes in driver and iron swing before and after wearing the functional golf inner-wear manufactured in this way were measured using trackman equipment. Measurement variables were limited to Club Speed, Attack Angle, Club Path, Ball Speed, Smash Factor, and Priority. Before and after wearing functional golf inner-wear, there were statistically significant differences in driver club speed, iron club speed, driver etch angle, iron club pass, driver ball speed, driver smash factor, iron smash factor, driver carry, iron carry, and right shoulder joint proprioceptive sensory ability. As a result, functional golf inner-wear is effective for ball speed, impact, and carry by increasing club speed and efficient swing. Future research will focus on the development of functional golf that can improve the swing ability in a short game that plays an important role in the golf game through various sports taping grafting technique, textile, special material, film, Research on functional golf inner-wear.