• Communications for Statistical Applications and Methods
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• 제22권1호
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• pp.69-80
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• 2015

In this paper, the probability that a given point is covered by a random convex hull generated by independent and identically-distributed random points in a plane is studied. It is shown that such probability can be expressed in terms of an integral that can be approximated numerically by function-evaluations over the grid-points in a 2-dimensional space. The new integral representation allows such probability be computed efficiently. The computational burdens under the proposed integral representation and those in the existing literature are compared. The proposed method is illustrated through numerical examples where the random points are drawn from (i) uniform distribution over a square and (ii) bivariate normal distribution over the two-dimensional Euclidean space. The applications of the proposed method in statistics are are discussed.

• ETRI Journal
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• 제43권3호
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• pp.400-413
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• 2021

This paper theoretically and empirically explores the reliability gain that can be obtained by installing multiple antennas in on-vehicle broadcasting receivers. Analytical derivations reveal that maximal-ratio-combining-based diversity allows a multi-antenna receiver (MR) to achieve significantly better coverage probability than a single-antenna receiver (SR). In particular, the notable MR gains for low-power reception and high-throughput services are highlighted. We also discuss various aspects of mobile MRs, including geometric coverage, volume of the users served, and impact of receiver velocity. To examine the feasibility of MRs in the real world, extensive field experiments were conducted, particularly with on-air ATSC 3.0 broadcast transmissions. Relying on the celebrated erroneous second ratio criterion, MRs with two and four antennas were verified to achieve notable reliability gains over SRs in practice. Furthermore, our results also prove that layered-division multiplexing can cope better with receiver mobility than traditional time-division multiplexing when multiple services are intended in the same radio frequency channel.

• 한국통신학회논문지
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• 제35권4A호
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• pp.394-400
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• 2010

Mobile Multi-hop Relay (MMR) 시스템은 커버리지 확장과 Base Station (BS) 내의 전송률 증대에 의해 무선 액세스 네트워크의 처리량을 증가시킬 수 있다. 넌-트랜스패런트 모드 (non-transparent mode) Relay Station (RS) 를 갖는 MMR 시스템의 기존 연구에서는 Mobile Station (MS)의 채널 선택 과정, 동일 채널 간섭, 그리고 Multi-hop Relay Base Station (MR-BS)과 RS의 커버리지 비율은 고려하지 않았다. 본 논문에서는 다양한 토폴로지를 갖는 멀티셀 환경에서 MMR 상향링크 시스템의 성능을 분석한다. 성능은 호 발생률에 따른 호 차단 확률, 채널 사용률, outage 확률 그리고 시스템 처리량으로 나타낸다. 결과를 통해 MR-BS와 RS의 커버리지 비율이 7 대 1일 때 시스템 처리량이 가장 높음을 알 수 있다.

• Journal of the Korean Data and Information Science Society
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• 제10권2호
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• pp.465-472
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• 1999

We considered a bootstrap method for constructing confidenc intervals for a one parameter model using multinomial sampling. The convergence rates or the proposed bootstrap method are calculated for model-based maximum likelihood estimators(MLE) using multinomial sampling. Monte Carlo simulation was used to compare the performance of bootstrap methods with normal approximations in terms of the average coverage probability criterion.

• Journal of the Korean Statistical Society
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• 제31권3호
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• pp.379-389
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• 2002

For two normal distribution with unknown means and unknown variances, a sequential procedure for estimating the difference of two normal means which satisfies both the coverage probability condition and the $\beta$-protection is proposed under some smoothness of variable imprecision function, and the asymptotic normality of the proposed stopping time after some centering and scaling is given.

• 센서학회지
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• 제22권4호
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• pp.268-275
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• 2013

Efficient energy management becomes a critical design issue for complex WSN (Wireless Sensor Network). Most of complex WSN employ the sleep mode to reduce the energy dissipation. However, it should cause the reduction of sensing coverage. This paper presents new wake-up algorithm for reducing energy consumption in complex WSN. The proposed wake-up algorithm is devised using geometric probability. It determined which node will be waked-up among the nodes having overlapped sensing coverage. The only one sensor node will be waked-up and it is ready to sense the event occurred uniformly. The simulation results show that the lifetime is increased by 15% and the sensing coverage is increased by 20% compared to the other scheduling methods. Consequently, the proposed wake-up algorithm can eliminate the power dissipation in the overlapped sensing coverage. Thus, it can be applicable for the various WSN suffering from the limited power supply.

• 응용통계연구
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• 제19권1호
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• pp.171-181
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• 2006

모비율 차이의 구간 추정에서 표준으로 인식되고 있는 Wald 신뢰구간은 모비율 구간 추정과 마찬가지로 포함확률의 근사성에서 문제가 있다는 것이 알려져 있다. 이에 대한 대안으로 모비율 차이의 신뢰구간에 대한 많은 연구가 있어 왔으나 대부분의 신뢰구간은 매우 복잡한 과정을 통해 얻어지게 되어 있어 실용성에 대한 문제가 제기될 수 있다. 이와 비교하여 Agresti와 Caffo(2000)에 의해 제시된 신뢰구간은 매우 간편한 식에 의해 구할 수 있어 이해하기 쉽고 포함확률과 포함확률의 평균절대오차에 있어 다른 복잡한 신뢰 구간과 필적할 수 있다. 그러나 Agresti-Caffo 신뢰 구간은 포함확률이 명목 신뢰수준을 상회하는 보수적인 구간으로 알려져 있다. 본 논문에서는 이승천(2005)에서 이항비율의 신뢰구간을 구하기 위해 사용된 가중 Polya 사후분포를 이용하여 두 모비율 차이의 신뢰구간을 구하였다. 이렇게 구하여진 신뢰구간은 간편성은 물론 Agresti-Caffo 신뢰구간의 보수성을 개선하였다.

• Communications for Statistical Applications and Methods
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• 제10권2호
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• pp.333-339
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• 2003

In this paper, we develop the probability matching priors for the parameters of non-regular Pareto distribution. We prove the propriety of joint posterior distribution induced by probability matching priors. Through the simulation study, we show that the proposed probability matching Prior matches the coverage probabilities in a frequentist sense. A real data example is given.

• Journal of the Korean Data and Information Science Society
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• 제22권6호
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• pp.1175-1182
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• 2011

본 연구는 초기하분포의 모수, 즉 성공의 확률에 대한 신뢰구간추정에 대하여 설펴보았다. 초기하분포의 성공의 확률에 대한 신뢰구간은 일반적으로 잘 알려져 있지 않으나 그 응용성과 활용성의 측면에서 신뢰구간의 추정은 상당히 중요하다. 본 논문에서는 초기하분포의 성공의 확률에 대한 정확신뢰구간과 이항분포와 정규분포에 의한 근사신뢰구간을 소개하고 여러 가지 모집단의 크기와 표본 수에 대하여, 그리고 몇 가지 관찰값에 대한 정확신뢰구간과 근사신뢰구간을 계산하고 소 표본의 경우에 모의실험을 통하여 실제포함확률의 측면에서 살펴보았다.

• Journal of information and communication convergence engineering
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• 제10권4호
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• pp.329-336
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• 2012

For designing broadcast protocols in mobile ad hoc networks (MANETs), one of the important goals is to reduce the rebroadcast packets redundancy while reaching all the nodes in network. In this paper, we propose a probabilistic broadcasting mechanism based on selfishness and additional coverage in MANETs. Our approach dynamically adjusts the rebroadcast probability according to the extra covered area and number of neighbor nodes. By these two factors, mobile hosts can be classified into three groups: normal, low selfishness, and high selfishness groups. The nodes in the normal group forward packets for other nodes with high probability, whereas the nodes in the low selfishness group rebroadcast packets with low probability and the nodes in the high selfishness group do not rebroadcast packets. We compared our approach with simple flooding and the fixed probabilistic approach. The simulation results show that the proposed schemes can significantly reduce the number of retransmissions by up to 40% compared simple flooding and fixed probabilistic scheme without significant reduction in the network reachability and end-to-end packet delay.