• Journal of the Korean Society for Precision Engineering
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• v.33 no.10
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• pp.781-787
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• 2016

We introduce FEST (Flight Environment Simulation Test) procedures for precise guided missiles to reliably improve systems. Flight vibration specification was established based on power spectral density curves calculated from flight test data of a high speed precise guided missile. A FEST pre-profile was developed according to flight vibration specification and delivered to a precise guided missile assembly. Vibration responses were measured by installing accelerometers on electronic components vulnerable to dynamic forces. The FEST profile was adjusted by comparing the vibration responses and the flight vibration specification. Subsequently, the FEST profile was repeatedly modified through trial and error, because the responses were similar to the flight environment. The modified FEST profile enabled performance testing of assembled precise guided missiles under simulated flight conditions on the ground, where unexpected errors could be corrected before the flight tests, leading to cost and risk reduction in the development of the precise guided missile system.

• Nuclear Engineering and Technology
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• v.19 no.4
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• pp.279-291
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• 1987

The event tree/fault tree techniques used in the current probabilistic risk assessment (PRA) of nuclear power plants are based on the binary and static description of the components and the system. While these techniques Bay be adequate in most of the safety studies, more advanced techniques, e.g., the Markov reliability analysis, are required to accurately study such problems as the plant availability assessments and technical specifications evaluations that are becoming increasingly important. This paper describes a Markov model for the Reactor Protection System of a pressurized water reactor and presents results of model evaluations for two testing policies in technical specifications.

• Journal of Korean Society for Quality Management
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• v.19 no.2
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• pp.96-107
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• 1991

At the design stage of a plant, the plausible causes and pathways of release of hazardous materials are not clearly known. Thus there exist large amount of uncertainties on the consequences resulting from the operation of a fusion plant. In order to better handle such uncertain circumstances, we utilize the Probabilistic Risk Assessment(PRA) for the safety analyses on fusion power plant. In this paper, we concentrate on the tritium release accident. We develop a simple model that describes the process and flow of tritium, by which we figure out the locations of tritium inventory and their vulnerability. We construct event tree models that lead to various levels of tritium release from abnormal initiating events. Branch parameters on the event tree are assessed from the fault tree analysis. Based on the event tree models we construct influence diagram models which are more useful for the parameter updating and analysis. We briefly discuss the parameter updating scheme, and finally develop the methodology to obtain the predictive distribution of consequences resulting from the operating a fusion power plant. We also discuss the way to utilize the results of testing on sub-systems to reduce the uncertain ties on over all system.

• Nuclear Engineering and Technology
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• v.29 no.3
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• pp.211-217
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• 1997

Adverse effects caused by the surveillance test for the components of nuclear power plant involve plant transients, unnecessary wear, burden on licensee's time, and the radiation exposure to personnel along with the characteristics of each component. The optimization methodology of STI and AOT has been developed and applied to AFWPs of a reference plant. The approach proposed in this paper consist of the resole in minimal mean unavailability of the two-out-of-four system with adverse effects are analytically calculated for the example system. The surveillance testing strategy are given by the sequential test, the staggered test and the train staggered test which is a mined test scheme. In the system level, the sensitivity analyses for the STI and AOT, are performed for the measure of the system unavailability of the top event in the fault tree developed for the example system. This methodology may contribute to establishing the basis for the risk-based regulations.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.151-152
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• 2018

The purpose of this study was to find out harmful effects of concrete, an essential material in modern architecture, on the human body. Based on the results from animal testing, we can consider the effects on the human body. The results of this study were as follows; Experimental Mouses in concrete have low body temperature due to cold radiation and more aggressive due to cold stress. Therefore, Cold radiation, a property of concrete, makes body temperature lower and affect the body's immune function.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.891-894
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• 2015

IT 프로젝트의 규모와 불확실성이 급변하고 있기 때문에 프로젝트를 계획된 비용과 납기 내에 성공적으로 종료하기가 어려워졌다. 이에 프로젝트 성공 가능성을 높이기 위한 방안으로 리스크 기반의 테스트 전략을 도입하여 적용하는 프로젝트 사례가 증가 하고 있다. 본 연구의 목적은 차세대 규모의 프로젝트를 수행할 때 리스크 기반의 테스트 전략을 어떻게 적용해야 하는지 사례를 통하여 구체적인 적용방안을 제시하고자 한다. 본 연구에서는 크게 두 가지 측면에서 시사점이 존재한다. 첫째, 차세대 규모의 프로젝트를 수행하기위해 전사적 차원에서 테스트 활동 방안을 제시하였다는 점이고, 둘째, 리스크 기반 테스트 전략을 프로젝트 라이프 사이클에 따라 적용한 사례를 통하여 구제적인 방안을 제시하였다는 점이다.

• KDI Journal of Economic Policy
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• v.41 no.1
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• pp.15-41
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• 2019

This paper economically analyzes the benefits and concerns of the sharing economy and derives policy implications that could help to achieve the expected benefits and respond appropriately to any concerns. Primary benefits anticipated from the sharing economy are the creation of new transactions and promotional and market testing opportunities, and the main concerns include the crowding out of existing transactions as well as transaction and social risks. How these benefits and concerns are being realized in Korea is empirically examined by conducting a survey on participation experiences with the sharing economy. The sharing economy is expected to contribute to the enhancement of social welfare with its wide range of benefits if risk factors can be properly controlled. Accordingly, an institutional framework is needed to support the stable growth of the sharing economy, and the unique characteristics of non-professional, peer-to-peer transactions should be reflected in tandem with regulatory equity between existing and sharing economy suppliers. To do this, transaction-volume-based regulations are recommended. Furthermore, to secure regulatory effectiveness and to alleviate transaction risks, the pertinent obligations must be imposed on sharing platforms.

• Journal of the Korea Society of Computer and Information
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• v.23 no.12
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• pp.241-248
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• 2018

Recently, there have been calls for approaching from the irrationality point of view to better explain the privacy paradox phenomenon. This study is a kind of response to them. The aim of the study is to investigate how satisfying competence needs, one of basic psychological needs suggested in self-determination theory, affects irrational information disclosure decision (i.e., risk-benefit assessment). To do this, the study builds an irrationality-based model in which competence needs satisfaction affects both perceived risks negatively and perceived benefits (i.e., relationship building and maintenance), which in turn determine a level of self-disclosure. Based on the data from Facebook users which is collected by a large sample survey (N=1050), the study analyzes it using Mplus, a powerful structure equation modeling tool. The study results reveal that while the relationship between competence needs satisfaction and perceived relationship building and maintenance is statistically significant, the relationship between competence needs satisfaction and perceived risks insignificant. These findings imply that people who is in a high level of competence needs satisfaction is more likely to respond to some opportunities for social benefits and in turn disclose more information about self.

• Journal of KIISE:Software and Applications
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• v.33 no.7
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• pp.605-614
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• 2006

The success of a software development project can be determined by the use of QCD. And as a software's size and complexity increase, the importance of early quality assurance rises. Therefore, more effort should be given to prevention, as opposed to correction. In order to provide a framework for the prevention of defects, defect detection activities such as peer review and testing, along with analysis of previous defects, is required. This entails a systematization and use of quality data from previous development efforts. FMEA, which is utilized for system safety assurance, can be applied as a means of software defect prevention. SW-FMEA (Software Failure Mode Effect Analysis) attempts to prevent defects by predicting likely defects. Presently, it has been applied to requirement analysis and design. SW-FMEA utilizes measured data from development activities, and can be used for defect prevention on both the development and management sides, for example, in planning, analysis, design, peer reviews, testing, risk management, and so forth. This research discusses about related methodology and proposes defect prevention model based on SW-FMEA. Proposed model is extended SW-FMEA that focuses on system analysis and design. The model not only supports verification and validation effectively, but is useful for reducing defect detection.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.2
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• pp.903-907
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• 2013

Primary screening by HPV DNA testing is an effective method for reducing cervical cancer and has proven more sensitive than cytology. To advance this approach, many molecular methods have been developed. Hybrid capture 2 provides semi-quantitative results in ratios of relative light units and positive cutoff values (RLU/PC). Twenty-five thousand and five patients were included in this study to analyze the correlation between the ratio of RLU/PC and stage of cervical dysplasia. The results show that the RLU/PC ratios ranged from 0-3500 while almost normal cases, ASC-US and ASC-H, had values below 200. Of those samples negative for cytology markers, 94.6% were normal and their RLU/PC ratios were less than 4. With an RLU/PC ratio greater than 4 and less than or equal to 300, the percentages in all age groups were normal 53.6%, LSIL 20.2%, ASC-US 17.2%, HSIL 6.13%, ASC-H 2.72%, and AGC 0.11%, respectively. In contrast, 64.0% of samples with a RLU/PC ratio greater than 300 and less than or equal to 3500 were LSIL. These results should contribute to cost effective cervical cancer management strategies. Further studies of associations with particular HPV genotypes would be useful to predict the risk of progression to cancer.