• 한국산업정보학회논문지
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• 제12권1호
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• pp.80-86
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• 2007

The concept of the coverage has been played an important role in the area of reliability evaluation of a system. The widely used measures of reliability include the m time between failures, the availability and so on. In this paper, we propose an estimator of the coverage probability in a redundant system with a control unit and investigate some moments of the proposed estimator. And assuming exponential distribution of all units, we conduct a simulation study for calculating the estimates of the coverage probability and its confidence bounds. An example of evaluating the availability of an optical transportation system is illustrated.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권4호
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• pp.1941-1960
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• 2019

Unmanned aerial vehicles (UAVs), acting as mobile base stations (BSs), can be deployed in the typical fifth-generation mobile communications (5G) scenarios for the purpose of substantially enhancing the radio coverage. Meanwhile, UAV aided underlay device-to-device (D2D) communication mode can be activated for further improving the capacity of the 5G networks. However, this UAV aided D2D communication system is more vulnerable to eavesdropping attacks, resulting in security risks. In this paper, the D2D receivers work in full-duplex (FD) mode, which improves the security of the network by enabling these legitimate users to receive their useful information and transmit jamming signal to the eavesdropper simultaneously (with the same frequency band). The security communication under the UAV coverage is evaluated, showing that the system's (security) capacity can be substantially improved by taking advantage of the flexible radio coverage of UAVs. Furthermore, the closed-form expressions for the coverage probabilities are derived, showing that the cellular users (CUs)' secure coverage probability in downlink transmission is mainly impacted by the following three factors: its communication area, the relative position with UAV, and its eavesdroppers. In addition, it is observed that the D2D users or DUs' secure coverage probability is relevant to state of the UAV. The system's secure capacity can be substantially improved by adaptively changing the UAV's position as well as coverage.

• Journal of the Korean Data and Information Science Society
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• 제14권1호
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• pp.83-92
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• 2003

In this paper, we derive noninformative priors for the ratio of parameters in the Burr model. We obtain Jeffreys' prior, reference prior and second order probability matching prior. Also we prove that the noninformative prior matches the alternative coverage probabilities and a HPD matching prior up to the second order, respectively. Finally, we provide simulated frequentist coverage probabilities under the derived noninformative priors for small and moderate size of samples.

• Communications for Statistical Applications and Methods
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• 제10권3호
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• pp.779-793
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• 2003

In this paper, various methods for finding confidence intervals for common odds ratio $\psi$ of the K 2${\times}$2 tables are reviewed. Also we propose two jackknife confidence intervals and bootstrap confidence intervals for $\psi$. These confidence intervals are compared with the other existing confidence intervals by using Monte Carlo simulation with respect to the average coverage probability.

• Communications for Statistical Applications and Methods
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• 제7권3호
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• pp.859-869
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• 2000

In this paper, various methods for finding confidence intervals for p of binomial parameter are reviewed. Also we introduce tow bootstrap confidence intervals for p. We compare the performance of bootstrap methods with other methods in terms of average coverage probability by Monte Carlo simulation. Advantages of these bootstrap methods are discussed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권8호
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• pp.3621-3640
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• 2016

In the process of k-coverage of the target node, there will be a lot of data redundancy forcing the phenomenon of congestion which reduces network communication capability and coverage, and accelerates network energy consumption. Therefore, this paper proposes a novel energy balanced k-coverage control algorithm based on probability model (EBKCCA). The algorithm constructs the coverage network model by using the positional relationship between the nodes. By analyzing the network model, the coverage expected value of nodes and the minimum number of nodes in the monitoring area are given. In terms of energy consumption, this paper gives the proportion of energy conversion functions between working nodes and neighboring nodes. By using the function proportional to schedule low energy nodes, we achieve the energy balance of the whole network and optimizing network resources. The last simulation experiments indicate that this algorithm can not only improve the quality of network coverage, but also completely inhibit the rapid energy consumption of node, and extend the network lifetime.

• Journal of the Korean Data and Information Science Society
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• 제13권2호
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• pp.317-328
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• 2002

We first derive group ordering reference priors in a two-way mixed-effects analysis of variance (ANOVA) model. We show that posterior distributions are proper and provide marginal posterior distributions under reference priors. We also examine whether the reference priors satisfy the probability matching criterion. Finally, the reference prior satisfying the probability matching criterion is shown to be good in the sense of frequentist coverage probability of the posterior quantile.

• Communications for Statistical Applications and Methods
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• 제18권1호
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• pp.71-77
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• 2011

In this paper, asymptotic results are investigated when a parametric transformation is applied to ARMA models. The conditions are determined to ensure the strong consistency and the asymptotic normality of maximum likelihood estimators and the correct coverage probability of the forecast interval obtained by the transformation and backtransformation approach.

• Communications for Statistical Applications and Methods
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• 제17권3호
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• pp.309-318
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• 2010

The construction of asymptotic confidence intervals is considered for the difference of binomial proportions in two doubly sampled data subject to false-positive error. The coverage behaviors of several likelihood based confidence intervals and a Bayesian confidence interval are examined. It is shown that a hierarchical Bayesian approach gives a confidence interval with good frequentist properties. Confidence interval based on the Rao score is also shown to have good performance in terms of coverage probability. However, the Wald confidence interval covers true value less often than nominal level.

• 응용통계연구
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• 제16권2호
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• pp.377-393
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• 2003

본 논문에서는 두 모비율의 차에 대한 기존의 신뢰구간들을 소개하고 붓스트랩 신뢰구간도 제안하였다 또한 모비율의 차에 대한 신뢰구간이 가지는 성질로서 근사신뢰구간의 하향추정의 문제와 정확신뢰구간의 상향추정의 문제점들을 확인하였고 평균포함 확률, 구간기대폭 그리고 왜도성 측면에서 종합적인 비교를 하였다. 특히 모수에 대한 사전분포를 가정하여 여러 신뢰구간들이 지니는 특징도 살펴보았다 기존의 신뢰구간들과 제안된 붓스트랩 신뢰구간은 소표본의 모의실험을 통하여 실제 포함확률의 평균을 기준으로 비교되었고 이항분포에서와 같이 정확신뢰구간이 지니는 보수성을 확인할 수 있었다. 신뢰구간의 평균포함확률의 등고선 그림도 소개하였다.