• Journal of the Korean Society for information Management
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• v.21 no.1
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• pp.173-186
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• 2004

This study examines coverage and coverage overlap of the three major Korean web directories, Naver, Yahoo Korea, and Empas. This study also suggests a methodology for collecting and processing web sites provided by these web directories. A method for napping main categories was developed. Each directory provided registered web pages in a slightly different way. Reference links had a significant influence on the coverage of each web directory. The overlap of pages among three directories was quite low, It is expected that this study could contribute to the field of web research by providing insights to how directories provide web pages and suggesting a methodology for the analysis of directory coverage.

• The KIPS Transactions:PartA
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• v.16A no.1
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• pp.35-42
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• 2009

This paper proposes a new coverage algorithm for intelligent robot. Many algorithms for improving the performance of coverage have been focused on minimizing the total coverage completion time. However, if one does not have enough time to finish the whole coverage, the optimal path could be different. To tackle this problem, we propose a new coverage algorithm, which we call MaxCoverage algorithm, for covering maximal area within the deadline. The MaxCoverage algorithm decides the navigation flow by greedy algorithm for Set Covering Problem. The experimental results show that the MaxCoverage algorithm performs better than other algorithms for random deadlines.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.848-850
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• 2014

Mobile Ad hoc Networks(MANET) is consist of node that has mobility, MANET build cluster formation for using energy efficient. In existing LEACH algorithm elect cluster head node in coverage area by distribution function. However, when the cluster head node, that elected by distribution function, is divided coverage area unevenly, the network can't consumption energy efficiency. To solve this problem, we proposed CSWC(Coverage Scheduling Weight-value Control) algorithm. When the coverage area is divided nonchalance, proposed algorithm increased number of hops, that determines coverage area, for balance coverage area. As the result proposed algorithm is set balance coverage area, the network consumption energy efficiency.

• The KIPS Transactions:PartD
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• v.15D no.3
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• pp.305-312
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• 2008

Web documents with useful information are widely available on the internet and they are accessible with web search service. For this reason, web search services study better ways to collect more web documents, but have a difficulty figuring out the coverage of these web pages. This paper is intended to find ways to evaluate the current coverage assessment methods and suggest more effective coverage assessment technique that is, sampling internet web documents equally, monitoring how they are classified on web search services, in an attempt to assess both absolute and relative coverage of the web search engines. The paper also presents the comparison among Korean web search services using the suggested methods.the absolute and relative coverage was highest in Google followed by Naver and Empas. The result is expected to help estimating coverage of web search services.

• KIPS Transactions on Software and Data Engineering
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• v.2 no.7
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• pp.451-460
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• 2013

In order to achieve high test coverage, it is usual to generate test data using various techniques including symbolic execution, data flow analysis or constraints solving. Recently, a technique for automated test data generation that fulfills high coverage effectively without those sophisticated means has been proposed. However, the technique shows its weakness in the generation of test data that leads to high coverage for programs having branch conditions where different memory locations are binded during execution. For certain programs with flag conditions, in particular, high coverage can not be achieved because specific branches are not executed. To address the problem, this paper presents dynamic branch coverage criteria and a test data generation technique based on the notion of dynamic branch. It is shown that the proposed technique compared to the previous approach is more effective by conducting experiments involving programs with flag conditions.

• Journal of the Korea Society of Computer and Information
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• v.15 no.1
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• pp.61-69
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• 2010

An autonomous robot must have a global workspace map in order to cover the complete workspace. However, most previous coverage algorithms assume that they have a grid workspace map that is to be covered before running the task. For this reason, most coverage algorithms can not be applied to complete coverage tasks in unknown environments. An autonomous robot has to build a workspace map by itself for complete coverage in unknown environments. Thus, we propose a new DmaxCoverage algorithm that allows a robot to carry out a complete coverage task in unknown environments. This algorithm integrates a SLAM algorithm for simultaneous workspace map building. Experimentally, we verify that DmaxCoverage algorithm is more efficient than previous algorithms.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.9
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• pp.1026-1037
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• 2016

3rd Generation Partnership Project (3GPP) is the progressing standardization of the narrowband IoT (NB-IoT) system to support massive devices for the Internet of Things (IoT) services. The NB-IoT system uses a coverage class technique to increase the performance of the NB-IoT system while serving massive devices in very wide coverage area. A moving device can change the coverage class according to the distance or the channel state between the base station and the moving device. However, in the conventional NB-IoT standard, the performance of the NB-IoT system degrades because the coverage class is changed based on the fixed criterion. This paper proposes the coverage class adaptation schemes to increase the performance of the NB-IoT system by dynamically change the coverage class according to the location or the channel state of the device. Simulation results show that the proposed coverage class adaptation scheme decreases both the signaling overhead and the PDCCH decoding error rate in comparison with the conventional coverage class adaptation scheme in the 3GPP standard.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.1
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• pp.18-25
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• 2013

In this paper, we propose a self-optimization scheme for indoor femtocell coverage in heterogeneous networks. If the femtocell coverage is larger than indoor area, neighbor cell users passing by the outer area of the femtocell coverage may request an unnecessary handover which incurs wasteful signaling overhead. On the other hand, if the coverage is smaller than the indoor area, some of indoor users might not be connected to the indoor femtocell. Therefore, we propose the method by which the femtocell coverage attains the exact indoor area employing self-organized scheme. Autonomous self TX power adjustment of the femtocell is possible because the proposed method utilizes handover request events and membership information of users that can be obtained by the femtocell itself. We show that the TX power obtained by the proposed algorithm converges to the optimal TX power that can be obtained analytically to attain the indoor coverage area.

• 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.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.10a
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• pp.423-425
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• 2016

콘콜릭 테스팅(Concolic testing)은 프로그램 실행을 실제 구체적인 입력 값(Concrete Values)을 입력하며, 동시에 심볼릭 실행 (Syrnbolic execution)을 진행하는 테스팅 기법이다. 콘콜릭 테스팅은 모든 실행 가능 경로를 탐색하여, 테스트 케이스를 자동 생생한다. 그래서 높은 분기 커버리지를 나타내지만, 안전성을 목표로 하는 MC/DC 커버리지는 만족하지 못한다. 본 논문에서는 분기 커버리지와 MC/DC 커버리지를 만족하는 테스트 케이스를 자동생성하는 CREST 도구 개선을 제안한다.