• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.3
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• pp.273-278
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• 2017

This paper is to study a technique to detect the real-time route aberrance on the passage route using bumper area of the ship domain theory. In order to evaluate the risk of route aberrance, a quarter line was created between the center line and the outer line, and a passage route with the image line outside the outer line was designed. It calculated the real-time route aberrance with the vessel bumper area to measure the risk level on the passage route. The route aberrance using overlap bumper area was simulated through three kinds of scenario vessel at the designed passage route. In this paper, we proposed Ratio to Aberrance Risk as one of the evaluation parameter to detect the route aberrance risk at each sector in the passage route and to give the evaluation criteria of 5 levels for seafarer's navigation safety. The purpose of this work is to provide the information of the route aberrance to seafarer automatically, to make it possible to prevent the human errors of seafarer on the high risk aberrance route. As the real-time risk of route aberrance on the passage route is automatically evaluated, it was well thought that seafarer can have only a little workload in order to know the risk of route aberrance at early-time. Following the further development of this work, the techniques for detecting the real-time route aberrance will be able to use the unmanned vessel.

• Journal of the Korean Data and Information Science Society
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• v.15 no.4
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• pp.879-889
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• 2004

This paper gives an approximation to the distribution function of the .rst passage time of stock price when volatility of stock price is modeled by a function of Ornstein-Uhlenbeck process. It also shows how to obtain the error of the approximation.

• Journal of the Chungcheong Mathematical Society
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• v.24 no.4
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• pp.687-693
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• 2011

This paper gives the stochastic comparison results for the first passage time distributions in the M/G/1 retial queue.

• Journal of the Korean Mathematical Society
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• v.35 no.3
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• pp.727-740
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• 1998

Controlling traffic lights at a bottleneck, in [5] a time of open passage is called optimal, if it minimizes the first moment of the asymptotic distribution of the queue length. The discussion of the first moment as function of the time of open passage is based on an analysis of the behavior of a fixed point when varying control parameters and delivers theoretical and computational aspects of the traffic problem.

• Journal of Mechanical Science and Technology
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• v.17 no.4
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• pp.545-561
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• 2003

We use the first-passage-time formulation by Torquato, Kim and Cule ［J. Appl. Phys., Vol. 85, pp. 1560∼1571 (1999) ］, which makes use of the first-passage region in association with the diffusion tracer's Brownian movement, and develop a new efficient Brownian motion simulation method to compute the effective conductivity of digitized composite media. By using the new method, one can remarkably enhance the speed of the Brownian walkers sampling the medium and thus reduce the computation time. In the new method, we specifically choose the first-passage regions such that they coincide with two, four, or eight digitizing units according to the dimensionality of the composite medium and the local configurations around the Brownian walkers. We first obtain explicit solutions for the relevant first-passage-time equations in two-and three-dimensions. We then apply the new method to solve the illustrative benchmark problem of estimating the effective conductivities of the checkerboard-shaped composite media. for both periodic and random configurations. Simulation results show that the new method can reduce the computation time about by an order of magnitude.

• Fashion & Textile Research Journal
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• v.8 no.2
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• pp.191-195
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• 2006

The purpose of this study was to identify the change of perception and preference of color according to time passage. The subjects were university students and for the survey 257 questionnaires in 1998 and 522 questionnaires in 2005 were effectively used to compare the perception and preference of color between the both period. The statistics was performed with frequency analysis and independent t-test in SPSS 10.0. The results were as follows. 1) Color perception according to time passage showed significant differences in red, yellow, green, and blue color. 2) Color preference according to time passage showed significant differences in red, green, and blue color. 3) Color perception among three regions according to time passage showed significant differences in red color in Seoul, yellow color in Seoul, Mokpo and Jeju, green color in Seoul and Mokpo, blue color in Seoul, Mokpo and Jeju, and purple color in Seoul. 4) Color preference among three regions according to time passage showed significant differences in yellow color in Mokpo, green and blue color in Seoul, Mokpo and Jeju.

• Journal of the Korean Data and Information Science Society
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• v.8 no.2
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• pp.119-125
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• 1997

We handle the stochastic processes of independent and identically distributed random variables. But random variables are usually dependent among themselves in actual life. So in this paper, we find out a new process not satisfying Markov property. We investigate the probability mass functions and study on the probability of the first-passage time. Also we find out the average frequency of continuous successes in from 0 to n time.

• The Korean Journal of Applied Statistics
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• v.30 no.1
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• pp.1-12
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• 2017

Many stochastic processes satisfy the Markov property exactly or at least approximately. An interested property in the Markov process is the first passage time. Since the sequential analysis by Wald, the approximation of the first passage time has been studied extensively. The Statistical computing technique due to the development of high-speed computers made it possible to calculate the values of the properties close to the true ones. This article introduces an exponentially weighted moving average (EWMA) control chart as an example of the Markov process, and studied how to calculate the average run length with problematic issues that should be cautioned for correct calculation. The results derived for approximation of the first passage time in this research can be applied to any of the Markov processes. Especially the approximation of the continuous time Markov process to the discrete time Markov chain is useful for the studies of the properties of the stochastic process and makes computational approaches easy.

• SUVANNABHUMI
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• v.1 no.1
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• pp.27-50
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• 2009

Although Malaysia chooses Islam as national religion, the nation has really shown a variety of belief systems among which we would find Hinduism, Buddhism, and Animism. Most scholars having studied them regarded the aspect of Malay traditional belief systems as syncretism. This trait of the belief systems in Malaysia is revealed well in the sphere specifically as the rite of passage, to which I do rather prefer the rite of "life" from the sense of emphasizing the rituals varied by the cycle of life time. Under the perspective this paper examines the real phases of the rite of passage, or life of Malays. I will argue here the fact that in performing the rite of passage, Malays mobilize various arts on the basis of the syncretic faith accepting the supernatural, or keramat, with almighty power. Therefore, from the study of the rite of passage we can exactly scrutinize how Malays have altered and adjusted their belief systems in real world.

• Journal of the Earthquake Engineering Society of Korea
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• v.18 no.2
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• pp.89-94
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• 2014

Spatial variations of a seismic wave are mainly wave passage and wave scattering. Wave passage effect is produced by changed characteristics of exciting seismic input motions applied to the bedrock. Modified input motions travel horizontally with time differences determined by apparent shear wave velocity of the bedrock. In this study, wave passage effect on the seismic response of a structure-soil system is investigated by modifying the finite element software of P3DASS (Pseudo 3-Dimensional Dynamic Analysis of a Structure-soil System) to apply inconsistent (time-delayed) seismic input motions along the soft soil-bedrock interface. Study results show that foundation size affected on the seismic response of a structure excited with inconsistent input motions in the lower period range below 0.5 seconds, and seismic responses of a structure were decreased considerably in the lower period range around 0.05 seconds due to the wave passage. Also, shear wave velocity of the bedrock affected on the seismic response of a structure in the lower period range below 0.3 seconds, with significant reduction of the seismic response for smaller shear wave velocity of the bedrock reaching approximately 20% for an apparent shear wave velocity of 1000m/s at a period of 0.05 seconds. Finally, it is concluded that wave passage effect reduces the seismic response of a structure in the lower period range when the bedrock under a soft soil is soft or the bedrock is located very deeply, and wave passage is beneficial for the seismic design of a short period structure like a nuclear container building or a stiff low-rise building.