• Journal of the Korean Statistical Society
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• v.31 no.3
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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.

• The KIPS Transactions:PartD
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• v.11D no.6
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• pp.1287-1294
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• 2004

Recently relationships between reliability measures and the coverage have been developed for evaluation of software reliability. Particularly the mean value function of the coverage-based software reliability growth model is important because of its key role in rep-resenting the software reliability growth. In this paper, we first review the problems of the existing mean value functions with respect to the assumptions on which they are based. Then a new mean value function is proposed. The new mean value function is developed for a general testing environment in which imperfect fault detection and repeated construct execution are allowed. Finally performance of the proposed model is empirically evaluated by applying it to a real data set.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.8
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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 Korea Institute of Information Security & Cryptology
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• v.30 no.6
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• pp.1079-1085
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• 2020

Fuzzing is used to find vulnerabilities for a library. Because library fuzzing only tests the implemented functions, in order to achieve higher code coverage, additional functions that are not implemented should be implemented. However, if a function is added without regard to the calling relationship of the functions in the library, a problem may arise that the function that has already been tested is added. We propose a novel method to improve the code coverage of library fuzzing. First, we analyze the function call graph of the library to efficiently add the functions for library fuzzing, and additionally implement a library function that has not been implemented. Then, we apply a hybrid fuzzing to explore for branches with complex constraints. As a result of our experiment, we observe that the proposed method is effective in terms of increasing code coverage on OpenSSL, mbedTLS, and Crypto++.

• Journal of the Korea Society of Computer and Information
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• v.12 no.4
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• pp.33-42
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• 2007

Accurate predictions of software release times, and estimation of the reliability and availability of a software product require quantification of a critical element of the software testing process : test coverage. This model called Enhanced non-homogeneous poission process(ENHPP). In this paper, exponential coverage and S-shaped model was reviewed, proposes the Kappa coverage model, which maked out efficiency application for software reliability. Algorithm to estimate the parameters used to maximum likelihood estimator and bisection method, model selection based on SSE statistics and Kolmogorov distance, for the sake of efficient model, was employed. From the analysis of mission time, the result of this comparative study shows the excellent performance of Burr coverage model rather than exponential coverage and S-shaped model using NTDS data. This analysis of failure data compared with the Kappa coverage model and the existing model(using arithmetic and Laplace trend tests, bias tests) is presented.

• Journal of the Korean Statistical Society
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• v.21 no.2
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• pp.139-151
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• 1992

Simultaneous confidence intervals for the parameters in the logistic regression models with random regressors are considered. A method based on the bootstrap and its stochastic approximation will be developed. A key idea in using the bootstrap method to construct simultaneous confidence intervals is the concept of prepivoting which uses the transformation of a root by its estimated cumulative distribution function. Repeated use of prepivoting makes the overall coverage probability asymptotically correct and the coverage probabilities of the individual confidence statement asymptotically equal. This method is compared with ordinary asymptotic methods based on Scheffe's and Bonferroni's through Monte Carlo simulation.

• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.1
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• pp.1-9
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• 2013

This study examined the effects of the occlusal stability and a partial coverage mouthguard on physical fitness and motor capacity to determine the importance of the occlusal stability as a possible action mechanism of mouthguards on physical performance. Twenty physical education students were included for measurements of their handgrip strength, back strength, whole body reaction time, flexibility, sidestep test, stork stand test and jumping test according to the following 5 different occlusal conditions: mouth closed position without a mouthguard, with a full coverage mouthguard, with a right partial coverage mouthguard, with a left partial coverage mouthguard and with anterior partial mouthguard. The results revealed no significant difference in any of the measured physical factors between the occlusal conditions with and without a full-coverage mouthguard. On the other hand, a significant difference was observed in whole body reaction between the occlusal conditions with and without the partial coverage mouthguards. Therefore, isokinetic muscle tests on both knee joints and the Wingate anaerobic power test should be performed under the following five occlusal conditions: with or without full-coverage maxillary custom-made mouthguard, with a unilateral right or left partial-coverage maxillary mouthguard and with an anterior partial-coverage maxillary mouthguard. These results suggest that the partial coverage mouthguard had a short-term beneficial effect on agility rather than full coverage mouthguard.

• The Journal of Advanced Prosthodontics
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• v.5 no.4
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• pp.388-395
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• 2013

PURPOSE. The purpose of this study was to estimate the effects of occlusal stability to identify action mechanisms of mouthguards, known to have a modulatory effect on limb muscle function. MATERIALS AND METHODS. This study included 20 male subjects to perform the isokinetic muscle tests and the Wingate anaerobic power test on both knee joints under five closed-mouth conditions: without or with 4 types of mouthguards with thickness of 2 mm based on premolar area: (1) full-coverage, (2) anterior partial-coverage, (3) right posterior partial-coverage, and (4) left posterior partial-coverage. The obtained results were subjected to One-way ANOVA with repeated measures, followed by post hoc test of the contrast method (${\alpha}$=.05). RESULTS. There was no significant difference between the closed position with and without a full-coverage mouthguard in all variables. However, significant differences were observed between with and without a partial-coverage mouthguard in muscular endurance during extension of the left knee, muscular power and endurance during flexion of the right knee. Additionally, significant differences were found between occlusal states with full- and partial-coverage mouthguards in muscular power and endurance during extension of the left knee. CONCLUSION. These findings indicate the elevation of vertical dimension by 2 mm or the inducement of occlusal stability had little effect on isokinetic muscle strength and anaerobic performance, while uneven distribution of occlusal force might have some positive effects.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.5A
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• pp.414-420
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• 2009

In this paper, we investigate throughput performance of OFDMA-based relay systems according to the "sub-cell coverage configuration" of the base station (RS) and the relay station (RS). RS is exploited for improved quality of the received signal with a tradeoff of additional radio resource consumption which may result in degradation of the throughput performance of the system. Therefore, "radio resource reuse" may be necessary for high performance in relay systems. However, it also causes system performance degradation since resource reuse between RSs incurs channel interference. Therefore, effective resource reuse also should be considered for "high throughput coverage configuration" when relays are employed. We relate the resource reuse patterns of neighboring RSs to sub-cell coverage configuration. We determine the sub-cell coverage of the system depending on the ratio of received signal-interference-noise-ratio (SINR) of the mobile station (MS) from the BS and RS, respectively. Simulations illustrate the throughput performance as the function of SINR ratio, and it has different optimal point depending on the resource reuse patterns. Therefore, the "resource reuse pattern" and the "effective sub-cell coverage configuration" should be considered together for the high throughput performance of the relay system.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.30 no.3
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• pp.443-454
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• 2020

The JavaScript engine is a module that receives JavaScript code as input and processes it, among many functions that are loaded into web browsers and display web pages. Many fuzzing test studies have been conducted as vulnerabilities in JavaScript engines could threaten the system security of end-users running JavaScript through browsers. Some of them have increased fuzzing efficiency by guiding test coverage in JavaScript engines, but no coverage guided fuzzing of optimized, dynamically generated machine code was attempted. Optimized JavaScript codes are difficult to perform sufficient iterative testing through fuzzing due to the function of runtime guards to free the code in the event of exceptional control flow. To solve these problems, this paper proposes a method of performing fuzzing tests on optimized machine code by avoiding deoptimization. In addition, we propose a method to measure the coverage of runtime-guards by the dynamic binary instrumentation and to guide increment of runtime-guard coverage. In our experiment, our method has outperformed the existing method at two measures: runtime coverage and iteration by time.