• Journal of the Korean Data and Information Science Society
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• 제26권3호
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• pp.653-659
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• 2015

야구의 피타고라스 정리는 야구의 승률을 추정하는 방법으로 오랜 기간 동안 타당성이 입증되고 또 활용되고 있다. 본 연구에서는 2005년부터 2014년 사이의 한국프로야구 팀대 팀 전체기록을 이용하여 실제승률과 피타고라스 정리에 의해 추정된 기대승률의 차이가 발생하는 원인을 회귀모형을 이용하여 살펴보았다. 기대승률과 실제승률의 차이가 큰 경우는 득점과 실점의 분포가 특이하다는 가정아래에서 종속변수는 실제승률과 기대승률의 차이, 독립변수로는 게임당 득점 및 실점의 평균, 표준편차, 변동계수를 각각 이용하였다. 그 결과 실제승률과 기대승률의 차이에는 게임당 실점의 표준편차와 변동계수가 영향을 미치며 게임당 득점의 영향은 없는 것으로 나타났다.

• 응용통계연구
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• 제29권7호
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• pp.1283-1294
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• 2016

한국 프로야구팀들의 실점을 설명하기 위한 수비지표를 연구하였다. 출루율과 장타율을 결합한 OPS가 팀들의 득점력을 매우 잘 설명한다는 사실을 동기로 하여 본 논문에서는 팀들의 실점을 설명하기 위한 수비지표를 연구하였다. 여러 가지의 수비지표 중 팀의 실점과 상관관계가 높은 것들을 결합하여 만든 몇 가지의 결합 지표들을 고려하였다. 프로야구 원년인 1982년부터 2015년까지의 정규리그 전 경기 자료를 분석한 결과 수정WHIP와 이닝당피홈런의 가중평균으로 정의되는 가중수정WPH2가 실점을 가장 잘 설명해줬다. 구체적으로 수정WHIP에 34%, 이닝당피홈런에 66%의 가중값을 두는 가중수정WPH2가 팀의 경기당 평균실점과 0.95362의 상관계수를 갖는 최적의 지표인 것으로 나타났다. 이 결과는 Kim과 Kim (2015a)에서 얻어진 지표에 의한 결과보다 좀 더 향상된 결과이다. 시대별 분석에서도 크게 다르지 않은 결과를 얻었다. 또한 얻어진 지표의 값이 좋은 투수 10명씩의 명단을 최근 3년간에 대해 연도별로 작성해보았다.

• 응용통계연구
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• 제28권5호
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• pp.1003-1011
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• 2015

한국 프로야구에서 팀들의 실점을 설명하기 위한 지표를 연구하였다. Kim과 Kim (2014)이 팀들의 득점력을 설명하기 위한 공격지표를 연구한 것과 유사하게 본 논문에서는 팀들의 실점을 설명하기 위한 수비지표를 연구하였다. 여러 가지의 수비지표 중 팀의 실점과 관련이 큰 것들을 결합하여 만든 몇 가지의 결합지표들을 고려하였다. 프로야구 원년인 1982년부터 2014년까지의 정규리그 전 경기 자료를 분석한 결과 WHIP와 경기당피홈런의 가중평균으로 정의되는 가중WPH가 실점을 가장 잘 설명해줬다. 구체적으로 WHIP에 81%, 경기당피홈런에 19%의 가중값을 주는 가중WPH가 팀의 평균실점과 0.95033의 상관계수를 갖는 최적의 가중WPH인 것으로 나타났다. 시대별 분석에서도 크게 다르지 않은 결과를 얻었다.

• Annals of Clinical Neurophysiology
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• 제8권1호
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• pp.44-47
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• 2006

Background: The present study used magnetoencephalography (MEG) to investigate the neural substrates for modified version of Treisman's visual search task. Methods: Two volunteers who gave informed consent participated MEG experiment. One was 27- year old male and another was 24-year-old female. All were right handed. Experiment were performed using a 306-channel biomagnetometer (Neuromag LTD). There were three task conditions in this experiment. The first was searching an open circle among seven closed circles (open condition). The second was searching a closed circle among seven uni-directionally open circles (closed condition). And the third was searching a closed circle among seven eight-directionally open circles (random (closed) condition). In one run, participants performed one task condition so there were three runs in one session of experiment. During one session, 128 trials were performed during every three runs. One participant underwent one session of experiment. The participant pressed button when they found targets. Magnetic source localization images were generated using software programs that allowed for interactive identification of a common set of fiduciary points in the MRI and MEG coordinate frames. Results: In each participant we can found activations of anterior cingulate, primary visual and association cortices, posterior parietal cortex and brain areas in the vicinity of thalamus. Conclusions: we could find activations corresponding to anterior and posterior visual attention systems.

• Journal of the Korean Data and Information Science Society
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• 제25권3호
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• pp.493-499
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• 2014

야구의 승률은 총득점의 제곱을 총득점의 제곱과 총실점의 제곱의 합으로 나눈 것으로 추정된다는 야구의 피타고라스 정리에 대하여 많은 연구들이 활발하게 진행되고 있다. 본 연구에서는 피타고라스 정리에 사용되는 지수에 대한 새로운 추정방법을 제안하며 평균제곱오차의 제곱근 (root mean squared error; RMSE)을 이용하여 널리 알려진 추정방법들과 상대적 효율성을 비교하였다. 사용된 데이터는 1982년부터 2013년 사이의 모든 한국프로야구 기록이며, 그 결과 제안된 방법은 기존의 방법보다 RMSE 관점에서 바람직하다고 간주된다.

• 산업경영시스템학회지
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• 제42권3호
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• pp.52-60
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• 2019

This paper presents a numerically robust algorithm to construct a Voronoi diagram of circles in the plane. The circles are allowed to have intersections among them, but one circle cannot fully contain another circle. The Voronoi diagram is a tessellation of the plane into Voronoi regions of given circles. Each circle has its Voronoi region which is defined by a set of points in the plane closer to the circle than any other circles. The distance from a point p to a circle $c_i$ of center $p_i$ and radius $r_i$ is ${\parallel}p-p_i{\parallel}-r_i$, which is the closest Euclidean distance from p to the circle boundary. The proposed algorithm first constructs the point Voronoi diagram of centers of given circles, then it enlarges each point to the circle and expands its Voronoi region accordingly. This region-expansion process is done by local modifications and after completing this process for the whole circles the desired circle Voronoi diagram can be obtained. The proposed algorithm is numerically robust and we provide with a few examples to show its robustness. The algorithm runs in $O(n^2)$ time in the worst case and O(n) time on average where n is the number of the circles. The experiment shows that the region-expansion algorithm is robust and runs fast with strong linear time behavior.

• Journal of Computing Science and Engineering
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• 제3권2호
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• pp.73-87
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• 2009

A hybrid system is a dynamical system in which states can be changed continuously and discretely. Simulation based on numerical methods is the widely used technique for analyzing complicated hybrid systems. Numerical simulation of hybrid systems, however, is subject to two types of numerical errors: truncation error and round-off error. The effect of such errors can make an impossible transition step to become possible during simulation, and thus, to generate a simulation behavior that is not allowed by the model. The possibility of an incorrect simulation behavior reduces con.dence in simulation-based analysis since it is impossible to know whether a particular simulation trace is allowed by the model or not. To address this problem, we define the notion of Instrumented Hybrid Automata (IHA), which considers the effect of accumulated numerical errors on discrete transition steps. We then show how to convert Hybrid Automata (HA) to IRA and prove that every simulation behavior of IHA preserves the discrete transition steps of some behavior in HA; that is, simulation of IHA is sound with respect to HA.

• ETRI Journal
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• 제25권1호
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• pp.25-33
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• 2003

This paper describes interactive dynamic simulation schemes for articulated bodies in virtual environments, where user interaction is allowed through a haptic interface. We incorporated these schemes into our dynamic simulator I-GMS, which was developed in an object-oriented framework for simulating motions of free bodies and complex linkages, such as those needed for robotic systems or human body simulation. User interaction is achieved by performing push and pull operations with the PHANToM haptic device, which runs as an integrated part of I-GMS. We use both forward and inverse dynamics of articulated bodies for the haptic interaction by the push and pull operations, respectively. We demonstrate the user-interaction capability of I-GMS through on-line editing of trajectories for 6-dof (degrees of freedom) articulated bodies.

• 한국의상디자인학회지
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• 제1권1호
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• pp.157-169
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• 1999

This study has investigated the Horse Culture and the Horse Owner‘s colours(Horse racing silks or Jockey’s costume). The results of this study revealed that the jockey‘s costume of western as well as Korean’s. According to the “International agreement on breeding and racing” in order to avoid too much variation between basic colours, grades of colours and colour combinations, a standard for owner‘s colours and jacket design has been agreed. Racing colours registered before the present agreement will however be allowed. Every horse coming from abroad runs in the registered colours of its owner in the country where the horse is trained. There are unique Korean jockey’s costume, They are going to change jockey‘s costume to Owner’s colours.

• 한국군사과학기술학회지
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• 제1권1호
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• pp.211-218
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• 1998

As a part of trajectory modulation to increase system survivability and terminal effectiveness, impact angle control is required in the terminal phase of tactical missile systems. The missile systems are not allowed to have high altitude to reduce probability of detection by sensors of missile defense systems. In this paper, an analytic form of a time-optimal control law is suggested in the case of constrained missile maneuverability and impact angle under the assumption of a zero-lag autopilot. The control law is obtained by establishing optimal missile-target engagement geometry in the vertical plane. Extension of the law for missiles with autopilot response lags requiring a numerical solution is studied by introducing an iterative algorithm for optimal switching time determination of which the initial switching instants are obtained from the analytic solution. Also suggested is a closed-form impact angle control law derived by an energy-optimal approach. The performances of the proposed guidance laws are evaluated by a series of computer runs.