• 대한수학회보
• /
• 제56권6호
• /
• pp.1497-1510
• /
• 2019

In this paper we compute the stopping times in the game Rock-Paper-Scissors. By exploiting the recurrence relation we compute the mean values of stopping times. On the other hand, by constructing a transition matrix for a Markov chain associated with the game, we get also the distribution of the stopping times and thereby we compute the mean stopping times again. Then we show that the mean stopping times increase exponentially fast as the number of the participants increases.

• 충청수학회지
• /
• 제8권1호
• /
• pp.11-17
• /
• 1995

Let ${\tau}_a$ be the first time that a perturbed random walk with extended real-valued independent and identically distributed (i.i.d.) random variables crosses a constant boundary $a{\geq}0$. For the stopping times ${\tau}_a$ we investigate some basic properties and obtain its limiting distribution as $a{\rightarrow}{\infty}$ and an upper bound of the expected stopping times E(${\tau}_a$).

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2011년도 전력전자학술대회
• /
• pp.296-297
• /
• 2011

Many applications involving induction motors that are controlled using variable frequency drives require the ability to stop quickly. These applications include emergency stops, quick stopping of fans, centrifuges, presses, etc. The technique that is widely accepted in the industry for achieving quick stopping makes use of brake resistors in series with a power semiconductor switch. The switch-resistor combination (brake-unit) is applied across the dc bus. The fastest decelerating time achievable depends on the size of the resistors and the switch employed. In this paper, the authors propose a novel method of achieving quick stopping times without the use of any brake-unit. Experimental test results with and without this method on a large inertia motor-load combination show that the proposed stopping method is able to reduce the stopping time significantly compared to normal decelerated stop without the need for a braking unit.

• Journal of the Korean Statistical Society
• /
• 제24권2호
• /
• pp.337-347
• /
• 1995

In the problem of some sequential estimation, the stopping times may be written in the form $N(c) = inf{n \geq n_0; n \geq c^2 S^2_n/\delta^2 (\bar{X}_n)}$ where ${s^2_n}$ and ${\bar{X}_n}$ are the sequences of sample variance and sample mean of the independently and identically distributed (i.i.d.) random variables with distribution $F_{\theta}(x), \theta \in \Theta$, respectively, and $\delta$ is either constant or any given positive real valued function. We obtain some asymptotic normality and asymptotic expectation of the N(c) in various limiting situations. Specially, uniform asymptotic normality and uniform asymptotic expectation of the N(c) are given.

• 한국경영과학회지
• /
• 제9권2호
• /
• pp.23-27
• /
• 1984

We Observe a sequence of i. i. d random variables with density f or g. Only if g is true we should stop the process. Hence. the testing problem is completely described by a stopping time. Among all stopping times with error probability of first kind not exceeding a given bound, the one-sided sequential probability ratio test has smallest expected sample size if g is true. Moreover, the generalized one-sided SPRT has smallest expected sample size for g in the class of stopping times with expected sample size under f not falling below a given bound.

• 정보통신설비학회논문지
• /
• 제8권4호
• /
• pp.207-215
• /
• 2009

In recent digital communication systems, the performance of Turbo Code used as the error correction coding method depends on the interleaver size influencing the free distance determination and iterative decoding algorithms of the turbo decoder. However, some iterations are needed to get a better performance, but these processes require large time delay. Recently, methods of reducing the number of iteration have been studied without degrading original performance. In this paper, the new method combining ME (Mean Estimate) stopping criterion with SDR (sign difference ratio) stopping criterion of previous stopping criteria is proposed, and the fact of compensating each method's missed detection is verified Faster decoding realizes that reducing the number of iterative decoding about 1~2 times by adopting our proposed method into serially concatenation of both decoder. System Environments were assumed DS-CDMA forward link system with intense MAI (multiple access interference).

• Restorative Dentistry and Endodontics
• /
• 제12권2호
• /
• pp.17-23
• /
• 1987

The purpose of this study was to evaluate the sealing properties of endodontic cavity filling materials according to the time intervals after filling. Access cavities were prepared in extracted human premolar or molar teeth and filled with caviton, zinc oxide eugenol cement, zinc oxide eugenol cement with a base of gutta percha stopping and gutta percha stopping. After filling at the intervals of immediate, 2 days and 2 weeks the teeth were immersed for 2 weeks in 1% methylene blue solutions. Longitudinal sections were obtained from approximately center of teeth and the depth of dye penetration into the access cavities were observed by 10${\times}$macrolens. The following results were obtained. I. All the materials experimented showed varying depth of dye penetration. 2. Of the material tested, caviton showed the best marginal sealing qualities regardless of the time intervals after filling and the sealing properties of the gutta percha stopping was the worst. 3. Both in zinc oxide eugenol cement and zinc oxide eugenol cement with a base of gutta percha stopping, the fillings allowed to mature for 2 days in normal saline solution showed the best sealing properties and those with no maturing time revealed the worst sealing qualities. 4. The sealing qualities of zinc oxide eugenol cement with a base of gutta percha stopping revealed slightly lower depth of dye penetration than that of zinc oxide eugenol cements.

• 조명전기설비학회논문지
• /
• 제25권8호
• /
• pp.39-47
• /
• 2011

The motion of a conductive spherical particle under uniform electric field is investigated in order to find a suitable method for removing the conducting solid impurities contained in liquid plastic. When the positive dc voltage applied to the upper electrode, the vertical up-and-down motion of a charged particle by electrostatic force is observed by a charge-coupled device (CCD) camera or a high-speed video camera. The experimental data of the static threshold voltage by which the particle starts to move toward the counter electrode in air or silicone oil are in good agreement with theoretical value. When the applied voltage is larger than the static threshold voltage, the particle motion pattern in silicone oil consists of four stages: upward motion, stopping at the upper electrode, downward motion and stopping at the lower electrode. The stopping motion on the electrode is thought to be caused by the liquid flow accompanied by the particle motion. The particle charge calculated by integrating the pulse current, which is generated by the charge exchange between the electrode and the particle, is approximately 0.1~0.25 times of the theoretical value. This study is expected to help understand the electric properties of microparticles in oil circuit breaker (OCB) and oil transformer and improve their performance and longevity.

• 수산해양교육연구
• /
• 제23권3호
• /
• pp.433-444
• /
• 2011

The purpose of this study is to examine the task of the policy on the collecting cargoes of the Japanese container ports. Although the ports of Asia countries such as China, South Korea have increased the amount of cargoes dramatically since the latter half of 1990s, the amount of cargoes Japanese container ports deal with have increased within narrow limits. As a result of this trend, the position of Japanese ports as hub-ports has been falling down. The times of main liners linked with North America and Europe stopping at Japanese ports have continued to decrease. So Japan container ports need the policy to increase the amount of cargoes in order to avoid becoming feeder ports. This policy is to collect domestic cargoes which are transshipped in Asia ports such as Busan port from Japanese regional ports to core ports. By collecting domestic cargoes to Japanese core ports intensively, the times of international main liners stopping at Japanese core ports will increase. It's important to support the domestic liners linking between Japanese regional ports and core ports in order to collecting domestic cargoes to Japanese core ports effectively. In addition the role of Japanese government to achieve the coordination between Japanese regional ports and core ports is indispensable.

• Journal of Nutrition and Health
• /
• 제23권1호
• /
• pp.1-10
• /
• 1990

$\omega$-3계의 지방산의 함량이 많은 어유는 혈청 지질을 저하시키므로 동맥경화증의 위험을 감소시킨다고 보고되어 있다. 그러나, 어유의 효과가 식이중 지방함량이 낮은 수준에서더 현저한가에 대해서는 확실히 알려져 있지 않다. 본 연구는 식사중 지방 함량이 서양인보다 적고,CHD의 예견인자가 다른 한국인에게, 실험군에 따라 1일 9g, 12g 및 15g 의 어유를 1주간 투여한후 혈청 지질을 조사한 결과는 다음과 같다. 1) 혈청 TC함량은 어유 투여 후 및 투여 중단 1주째에 유의적인 감소(p<0.01)를 나타내었으며, 혈청 TG함량은 어유 투여 후에 유의적인 감소를 나타내었다. 2) 혈청 지단백질의 전기영동 결과, VLDL함량은 유의적인 변화를 나타내지 않았고, LDL은 투여중단 1주째에 세 군 모두에서 유의적인 감소(p<0,05)를 나타내었으며, HDL은 9g군에서만 유의적인 증가(p<0.05)를 나타내었다. 3) HDL-C함량은 12g군과 15g군에서 투여 중단 1주째 및 투여 중단 3주째에 유의적인 증가(p<0.05)를 나타내었다. LDL-C 함량은 투여 후 유의적인 감소(p<0.05)를 나타내었고, 투여 중단 1주째에 세 군 모두에서 유의적인 감소(p<0.001)를 나타내었다.