• 수산해양기술연구
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• 제43권3호
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• pp.222-231
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• 2007

This paper represents a basic statistical examination on the navigability of ocean-going ship from the point of estimating the time lasting period when propeller racing occurred by using the basic probability theory and the statistics. The propeller racing is one of the most important seakeeping qualities in relation to the safety of the main engine and shafting system. The trend of the racing has been mainly investigated in order to estimate allowable maximum propeller diameter, operation of ocean-going ships, etc.. In those studies, the propeller racing generally and mainly means the situation (propeller exposed) in which the relative motion amplitude between ship hull and wave surface would exceed a depth of point in rotary disk propeller. Therefore, it seems that the magnitude of the amplitude and its exceeding frequency of propeller racing have been examined as a principal subject of study as usual. However, the time during which the amplitude exceeds the depth of point, that is, the propeller exposes in the air, must be also one of most important factor affecting the trend of propeller racing. Then, this paper proposes a new practical method for estimating the time lasting of exposed propeller related to propeller racing in rough-confused seas on the basis of the linear strip theory and the statistics. And, numerical examples of estimating the propeller racing probability are given for four wide ship forms. Finally the usefulness of the proposed method for predicting propeller racing based on the time lasting period is discussed.

• 동력기계공학회지
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• 제11권1호
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• pp.98-106
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• 2007

This paper presents a statistical prediction procedure for the propeller racing of ships with twin screw propellers sailing in ocean waves. The propeller racing is one of the most important factors of seakeeping qualities in relation to the safety of main engine and shafting system. It is especially significant key word for designing the twin-screw-propeller-type ship in view of allowable maximum propeller diameter etc.. In former studies, the propeller racing generally means the situation (propeller exposed) in which the relative motion amplitude between ship hull and wave surface would exceed a depth of point in rotary disk propeller. Therefore, it seems that the magnitude of the amplitude and its exceeding frequency have been examined as a principal subject of study as usual. However, the time during which the amplitude exceeds a depth of point must be also one of most important factor affecting the trend of propeller racing. This paper proposes a simply practical method for estimating the time lasting of exposed propeller related to twin screw propeller racing in rough confused seas on the basis of the statistics. Then, it is confirmed that the practical method is useful and convenience for considering the propeller racing in the stage of the basic design.

• 대한수의학회지
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• 제37권3호
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• pp.525-532
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• 1997

The hoof parameters - hoof angle, toe length, heel length, hoof width, hoof length, heel width, hoof circumference - of 1372 Thoroughbred racehorses in Seoul racecourse were measured. Each parameter was compared with the racing time. The parameters were as follows: fore hoof angle $50.1{\pm}0.09^{\circ}$, hind hoof angle $50.1{\pm}0.08^{\circ}$; fore toe fength $82.8{\pm}0.21mm$, hind toe length $88.8{\pm}0.23mm$; fore heel length $28.6{\pm}0.19mm$, hind heel length $24.5{\pm}0.19mm$; fore hoof width $130.9{\pm}0.30mm$, hind hoof width $125.7{\pm}0.28mm$; fore hoof length $133.3{\pm}0.22mm$, hind hoof length $28.1{\pm}0.22mm$; fore heel width $61.2{\pm}0.32mm$, hind heel width $67.9{\p}0.35mm$; fore hoof circumference $264.2{\pm}0.48mm$, hind hoof circumference $253.8{\pm}0.40mm$. Apart from the hoof angle, the hoof parameters increased in proportion to the body weight. The parameters of forelimbs affected the racing time more than those of hindlimbs. The correlation between hoof parameters and racing time was shown more in short-distance race (1000M) than in long-distance race(2200M). The parameters that had correlation with racing time were hoof width, hoof length, heel width of forelimbs and heel width of hindlimbs.

• 자동차안전학회지
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• 제16권1호
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• pp.6-11
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• 2024

This paper presents a motion planning algorithm of autonomous racing vehicles for mimicking the characteristics of a human driver. Time optimal maneuver of a race car has been actively studied as a major research area over the past decades. Although the time optimization problem yields a single time series solution of minimum time maneuver inputs for the vehicle, human drivers achieve similar lap times while taking various racing lines and velocity profiles. In order to model the characteristics of a specific driver and reproduce the motion, a stochastic motion planning framework based on kernelized motion primitive is introduced. The proposed framework imitates the behavior of the generated reference motion, which is based on a small number of human demonstration laps along the racetrack using Gaussian mixture model and Gaussian mixture regression. The mean and covariance of the racing line and velocity profile mimicking the driver are obtained by accumulating the outputs tested at equidistantly sampled input points. The results confirmed that the obtained lateral and longitudinal motion simulates the driver's driving characteristics, which are feasible for actual vehicle test environments.

• Journal of Animal Science and Technology
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• 제50권6호
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• pp.741-746
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• 2008

본 연구는 한국마사회로부터 수집한 8,197두의 경주기록 총 155,656개를 이용하여 더러브렛 경주마의 체중변화가 주파기록에 미치는 효과를 구명하기 위하여 수행되었다. 국내 더러브렛 경주마의 평균 체중은 449kg 이었으며, 거세말, 수말과 암말의 평균 체중은 각각 460kg, 454kg과 441kg으로 수말의 체중이 가장 높게 나타났다. 암말의 경우 체중의 감소는 3월, 4월과 5월사이에 가장 크게 나타나며, 수말과 거세마의 경우 5월, 6월과 7월에 체중의 감소가 가장 크게 나타났다. 전반적으로 경주마의 체중은 봄과 여름에 감소하며, 가을과 겨울에 증가하는 현상을 나타내었다. 주파기록에 대한 유전력과 반복력은 각각 0.237과 0.525였으며, 체중에 대한 유전력은 0.612로 추정되었다. 직전 경주 대비 체중의 변화가 ±10kg 이상일 때 주파기록은 현저히 증가하였으며, 직전 경주 대비 체중의 변화가 ±20kg인 경우는 ±5kg인 경우와 비교했을 때 주파기록의 차이가 0.3초 정도 증가하였다. 체중의 변화가 체중에 비례하여 ±0.5% 정도 변화하였을 때 주파기록이 가장 우수하였으며, 체중의 변화가 체중 대비 ±2.5% 이상이 되면 경주능력은 현저히 감소하였다.

• 한국자동차공학회논문집
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• 제11권4호
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• pp.220-225
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• 2003

In this paper, various types of racing line are analyzed for the best time to go through a 90 degree comer. 'Best' means the least time, at the greatest average speed. The comer concerned here has the long straights before and after the corner so that the vehicle is able to n with its maximum speed along the straights. It is shown that both inside and outside driving lines including the modified outside driving lines never beat classical racing line. It is also found that outside driving line is better than inside driving inside driving line as long as there are straight lines before and after the comer.

• 문화기술의 융합
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• 제8권2호
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• pp.393-398
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• 2022

현실에서의 자동차 레이싱을 체험 및 경기를 진행하기 위해서는 진입 하려는 장벽이 매우 높다. 라이센스, 고액의 차량, 경기를 할 수 있는 경기장을 섭외 하거나 참여하려면 많은 비용과 시간이 필요하다 동시에 현실의 자동차 레이싱은 많은 위험성을 가지고 진행 된다. 이러한 문제가 있기 때문에 심레이싱 장비를 통해서 각자만의 공간에서 현실의 레이싱과 비슷한 느낌을 만들기 위해서 여러 가지 장비를 이용한다. 이러한 현실과 비슷한 장비를 심레이싱 장비라고 한다. 심레이싱 장비는 총 세 가지로 나눌 수 있다. 첫 번째로는 가상 레이싱을 실행 할 수 있는 레이싱 게임 장치, 두 번째로는 레이싱 게임 장치와 연동이 되는 핸들과 시트 및 거치대, 세 번째로는 레이싱 게임에서 움직이는 방향을 몸에 체험시키기 위한 레이싱 모션 장치들이 있다. 본 논문에서는 현실의 자동차 레이싱의 느낌을 게임 레이싱의 기반으로 게임 레이싱을 컨트롤 할 수 있는 장비인 핸들과 거치대 장비와 게임 레이싱의 방향을 체험 할 수 있는 모션장비를 통해서 현실의 레이싱과 얼마나 비슷한 현실을 가지고 있는 지 G-Force의 방향과 속도변화의 값을 통해 현실의 레이싱과 데이터 값의 변화가 어떻게 차이가 있는지 확인 해보겠다.

• Animal Bioscience
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• 제35권5호
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• pp.659-669
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• 2022

Objective: Thoroughbred horses have been bred exclusively for racing in England for a long time. Additionally, because horse racing is a global sport, a healthy leisure activity for ordinary citizens, and a high-value business, systematic racehorse breeding at the population level is a requirement for continuous industrial development. Therefore, we established genomic evaluation system (using prize money as horse racing traits) to produce spirited, agile, and strong racing horse population Methods: We used phenotypic data from 25,061 Thoroughbred horses (all registered individuals in Korea) that competed in races between 1994 and 2019 at the Korea Racing Authority and constructed pedigree structures. We quantified the improvement in racehorse breeding output by year in Korea, and this aided in the establishment of a high-level horse-fill industry. Results: We found that pedigree-based best linear unbiased prediction method improved the racing performance of the Thoroughbred population with high accuracy, making it possible to construct an excellent Thoroughbred racehorse population in Korea. Conclusion: This study could be used to develop an efficient breeding program at the population level for Korean Thoroughbred racehorse populations as well as others.

• Journal of Animal Science and Technology
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• 제50권6호
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• pp.747-752
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• 2008

본 연구는 1990년 1월부터 2006년 12월말까지 지난 17년간 과천경마공원에서 경주한 경주마 9,934두의 주파기록, 총 208,043개를 이용하여 속도형질들에 대한 경주년도별 개량 추세를 분석하였다. 속도형질로는 반복 주파기록, 우승마 주파기록, 거리별 연간 최고 주파기록 세 가지를 분석하였으며, 이들에 대한 유전율은 각각 0.288, 0.275와 0.341로 추정되었고 반복율은 각각 0.502, 0.475와 0.496이었다. 경주속도 형질들에 대한 연간 표현형 개량량은 －0.115 ~－0.148초의 범위를 나타내었다. 반면 반복 주파기록에 대한 연간 유전적 개량량은 －0.027초 추정되었으나 나머지 형질들에 대해서는 유의성이 인정되지 않았다. 따라서 더러브렛 경주마의 개량형질로는 반복 주파기록을 이용하는 것이 바람직할 것으로 생각된다.

• 한국자동차공학회논문집
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• 제11권6호
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• pp.141-146
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• 2003

This paper calculates the elapsed time to go down a straight as a function of the corner exit speed and considers air resistance, rolling resistance, and slope resistance to figure out the force for forward acceleration. In a car racing, the most critical comer in a course is the one before the longest straight. A driver can lose a quite amount of time by taking a bad line in a corner. Taking a bad line also causes poor comer exit speed which in turn costs more elapsed time to go down a straight. The results are not so dramatic as in the case of cornering but are showing why one should take the correct corner racing line to get the maximum exit speed. Also, for the case of drag race, the elapsed time to go 1/4 mile is calculated.