• ETRI Journal
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• 제42권3호
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• pp.388-398
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• 2020

We herein propose a heuristic redundancy selection algorithm that combines resubmission, replication, and checkpointing redundancies to reduce the resiliency overhead in fault-tolerant workflow scheduling. The appropriate combination of these redundancies for workflow tasks is obtained in two consecutive phases. First, to compute the replication vector (number of task replicas), we apportion the set of provisioned resources among concurrently executing tasks according to their needs. Subsequently, we obtain the optimal checkpointing interval for each task as a function of the number of replicas and characteristics of tasks and computational environment. We formulate the problem of obtaining the optimal checkpointing interval for replicated tasks in situations where checkpoint files can be exchanged among computational resources. The results of our simulation experiments, on both randomly generated workflow graphs and real-world applications, demonstrated that both the proposed replication vector computation algorithm and the proposed checkpointing scheme reduced the resiliency overhead.

• Journal of Power Electronics
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• 제13권4호
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• pp.719-728
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• 2013

A novel hybrid active power filter (NHAPF) that can be adopted in high-voltage systems is proposed in this paper. The topological structure and filtering principle of the compensating system is provided and analyzed, respectively. Different controlling strategies are also presented to select the suitable strategy for the compensation system. Based on the selected strategy, the harmonic suppression function is used to analyze the influence of system parameters on the compensating system with MATLAB. Moreover, parameters in the injection branch are designed and analyzed. The performance of the proposed NHAPF in harmonic suppression and reactive power compensation is simulated with PSim. Thereafter, the overall control method is proposed. Simulation analysis and real experiments show that the proposed NHAPF exhibits good harmonic suppression and reactive power compensation. The proposed compensated system is based on the three-phase four-switch inverter, which is inexpensive, and the control method is verified for validity and effectiveness.

• Communications for Statistical Applications and Methods
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• 제25권3호
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• pp.307-319
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• 2018

High-throughput technologies enable the simultaneous evaluation of thousands of genes that could discriminate different subclasses of complex diseases. Ranking genes according to differential expression is an important screening step for follow-up analysis. Many statistical measures have been proposed for this purpose. A good ranked list should provide a stable rank (at least for top-ranked gene), and the top ranked genes should have a high power in differentiating different disease status. However, there is a lack of emphasis in the literature on ranking genes based on these two criteria simultaneously. To achieve the above two criteria simultaneously, we proposed to apply a previously reported metric, the modified area under the receiver operating characteristic cure, to gene ranking. The proposed ranking method is found to be promising in leading to a stable ranking list and good prediction performances of top ranked genes. The findings are illustrated through studies on both synthesized data and real microarray gene expression data. The proposed method is recommended for ranking genes or other biomarkers for high-dimensional omics studies.

• 기술혁신연구
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• 제10권1호
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• pp.201-217
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• 2002

Researchers, institutes, and government involved in research & development (R&D) are faced with the problem of performing R&D project evaluations. As a real-word case of evaluation, we elicited and reproduced the evaluation process of the national nuclear R&D projects, using a specific case study of Korea. In the methodology, the analytic hierarchy process (AHP) is employed to evaluate and rank the selected nuclear R&D projects which have a wide range of evaluation objectives and characteristics. As a result, we obtained relative ranking for research projects and importance of evaluation criteria. The method and implications can be easily understood and applied by practitioners since it follows naturally the standard practice of evaluating and relative comparisons of performance using evaluation procedures. By applying particular R&D project output to the procedures, project evaluators can compare and prioritize evaluation objectives.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2003년도 추계학술대회
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• pp.97-103
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• 2003

In recent years, environments of business are changing due to epoch-making development of information technology and the advent of digital economy ages. It is an active confrontation as to the environments for information. Unlike the large scale enterprises in those days, hower, many small & medium enterprises especially the enterprises which are engaged in the manufacturing industry-aren't participate in information's rank due to the lack of funds, manpower, insufficient management environments, and manager or staff's lack of cognition as to information. So, this paper make a base of establishment for ISP through the establishment of ERP that is used to management activity for small & medium manufacturing enterprises. A way for small & medium enterprises' ERP construction is SMERP S/W for the small & medium enterprises' ERP package which is offered by the Korea chamber of commerce & industry. And, that is applied to the real management environment.

• 한국기술혁신학회:학술대회논문집
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• 한국기술혁신학회 2001년도 춘계학술대회:발표자료
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• pp.369-385
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• 2001

A R&D project evaluation method has been applied for the national nuclear R&D projects in a developing-country setting. In the methodology, Saaty's analytic hierarchy process model is used to evaluate and rank of the selected nuclear R&D project which have a wide range of objectives and characteristics. The criteria used for evaluation related specifically to the Korea's evaluation needs and culture, and they are weighted according to their relative importance as perceived by the evaluator of the R&D project. As a real-world case of evaluation, we elicited and reproduced the evaluation process of the nuclear R&D projects which is going under the research process. As the results of the paper suggests, the methodology can be applied to the evaluation of the R&D projects and has much potential.

• Journal of the Korean Data and Information Science Society
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• 제28권4호
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• pp.947-955
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• 2017

A competing risk analysis has been applied when subjects experience more than one type of end points. Geskus (2011) showed three types of estimators of CIF are equivalent under left truncated and right censored data. We extend his approach to an interval censored competing risk data by using a modified risk set and evaluate their performance under several sample sizes. These estimators show very similar results. We also suggest a test statistic combining Sun's test for interval censored data and Gray's test for right censored data. The test sizes and powers are compared under several cases. As a real data application, the suggested method is applied a data where the feasibility of the vaccine to HIV was assessed in the injecting drug uses.

• 대한안전경영과학회지
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• 제5권4호
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• pp.107-115
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• 2003

In recent years, environments of business are changing due to epoch-making development of information technology and the advent of digital economy ages. It is an active confrontation as to the environments for information. Unlike the large scale enterprises in those days, hower, many small & medium enterprises especially the enterprises which are engaged in the manufacturing industry-aren't participate in information's rank due to the lack of funds, manpower, insufficient management environments, and manager or staff's lack of cognition as to information. So, this paper make a base of establishment for ISP through the establishment of ERP that is used to management activity for small & medium manufacturing enterprises. A way for small & medium enterprises' ERP construction is SMERP S/W for the small & medium enterprises' ERP package which is offered by the Korea chamber of commerce & industry. And, that is applied to the real management environment.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권4호
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• pp.2180-2197
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• 2019

With the proliferation of the Android malicious applications, malware becomes more capable of hiding or confusing its malicious intent through the use of code obfuscation, which has significantly weaken the effectiveness of the conventional defense mechanisms. Therefore, in order to effectively detect unknown malicious applications on the Android platform, we propose DroidVecDeep, an Android malware detection method using deep learning technique. First, we extract various features and rank them using Mean Decrease Impurity. Second, we transform the features into compact vectors based on word2vec. Finally, we train the classifier based on deep learning model. A comprehensive experimental study on a real sample collection was performed to compare various malware detection approaches. Experimental results demonstrate that the proposed method outperforms other Android malware detection techniques.

• Communications for Statistical Applications and Methods
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• 제26권4호
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• pp.411-430
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• 2019

Tumor development is driven by complex combinations of biological elements. Recent advances suggest that molecularly distinct subtypes of breast cancers may respond differently to pathway-targeted therapies. Thus, it is important to dissect pathway disturbances by integrating multiple molecular profiles, such as genetic, genomic and epigenomic data. However, missing data are often present in the -omic profiles of interest. Motivated by genomic data integration and imputation, we present a new statistical framework for pathway significance analysis. Specifically, we develop a new strategy for imputation of missing data in large-scale genomic studies, which adapts low-rank, structured matrix completion. Our iterative strategy enables us to impute missing data in complex configurations across multiple data platforms. In turn, we perform large-scale pathway analysis integrating gene expression, copy number, and methylation data. The advantages of the proposed statistical framework are demonstrated through simulations and real applications to breast cancer subtypes. We demonstrate superior power to identify pathway disturbances, compared with other imputation strategies. We also identify differential pathway activity across different breast tumor subtypes.