• Nuclear Engineering and Technology
• /
• v.47 no.2
• /
• pp.204-211
• /
• 2015

Probabilistic safety assessment (PSA) has had a significant role in quantitative decision-making by finding design and operational vulnerabilities and evaluating cost-benefit in improving such weak points. In particular, it has been widely used as the core methodology for risk-informed applications (RIAs). Even though the nature of PSA seeks realistic results, there are still "conservative" aspects. One of the sources for the conservatism is the assumptions of safety analysis and the estimation of failure frequency. Surveillance, diagnosis, and prognosis (SDP), utilizing massive databases and information technology, is worth highlighting in terms of its capability for alleviating the conservatism in conventional PSA. This article provides enabling techniques to solidify a method to provide time- and condition-dependent risks by integrating a conventional PSA model with condition monitoring and prognostics techniques. We will discuss how to integrate the results with frequency of initiating events (IEs) and probability of basic events (BEs). Two illustrative examples will be introduced: (1) how the failure probability of a passive system can be evaluated under different plant conditions and (2) how the IE frequency for a steam generator tube rupture (SGTR) can be updated in terms of operating time. We expect that the proposed model can take a role of annunciator to show the variation of core damage frequency (CDF) depending on operational conditions.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.32 no.3
• /
• pp.474-485
• /
• 2008

The purpose of this study is to examine the determinants and elements to enhance Korean international competitiveness, employing Porter's(1998) Diamond Model. Half of the 500 leading apparel exporters that were members of the Korea Apparel Industry Association in 2003 were selected as the target of this research. From May to June of 2003, survey questionnaires were sent to executives of these 250 companies in person or by telephone, e-mail, or fax. Seventy questionnaires were used for the final data anlysis. The items used were Reliability, Categorical Regression, and Frequency, using SPSS 11.5. The results were as follows: First, as a result of analyzing the influence of international competitiveness in Korean apparel industry, the firm's strategy, structure, and rivalry was the most influential factor. Others were related and supporting industries, government, chance, demand conditions, and factor conditions. Also, the elements that affect Korean international competitiveness were listed as the level of price competition in foreign markets, the level of labor cost, export marketing capacity, and exchange fluctuation. The most important element to improve the international competitiveness of the Korean apparel industry was a demand growth rate of the overseas markets(Demand Conditions), followed by the level of the labor costs(Factor Conditions), the capability of internationalization(Firm Strategy, Structure, and Rivalry), the change of currency(Chance), the quality and management of products(Demand Conditions), the capability of planning products(Firm Strategy, Structure, and Rivalry), free trade from 2005(Chance), and global sourcing strategy(Firm Strategy, Structure, and Rivalry). Korea's main rival country in apparel related and supporting industry factors is China. However, Korea has a higher level of technology development, quality, and price level than China.

• Journal of Internet Computing and Services
• /
• v.15 no.1
• /
• pp.1-17
• /
• 2014

Flight software operated on the on-board computers in the satellite has requirements such as real-time, high reliability. These requirements make dependency between the flight software and operating environments. Further, whenever a new system is built, such problem drives that all flight software are redeveloped. Thus, the dependency problem between them should be solved. And the problem can be resolved by improving the portability of the flight software. In order to improve the portability it is required to minimize the porting cost. In this paper, we classify the portability with the portability achieving methods. Using the classified portability, we propose a platform architecture that is based on the IMA concept and provides various portability capabilities. The proposed architecture enables us to solve the problem about the development of the flight software.

• Journal of Energy Engineering
• /
• v.25 no.4
• /
• pp.1-6
• /
• 2016

Seawater desalination plants generally have two inherent problems which stem from energy inefficiency and desalination concentrate management. The former has been somewhat resolved thanks to the innovative methods in utilizing new and renewable energy resources whereas the latter still has much issues to be dealt with. This paper introduces the application of a desalting process for the disposal of desalination concentrate (especially, Mg) and to improve its cost effectiveness of a MVR seawater desalination plant built in Jeju. Principal component analysis on the desalination concentrate has revealed a steady reduction of Mg with the application of the desalting process verifying its functional reliability. Also, it was found that our MVR seawater desalination plant is not only energy efficient but also could be effectively applied for the dual purpose of fresh water production and concentrate management.

• Journal of Preventive Medicine and Public Health
• /
• v.20 no.2 s.22
• /
• pp.270-279
• /
• 1987

In all enterprises of Korea employing workers more than five, employeers have a duty of conducting a periodic health screening for improvement and maintaining healthful living and working conditions of employees. The health screening is performed annually in line workers and biennially in table workers under the supervision of the government. But there are some argument to the health screening programme in view of effectiveness, efficiency, reliability and etc. In order to obtain basic reference materials for increasing the efficiency of peridoic health screening programme for workers and understand the attitude of health screening institutions and enterprises toward the periodic health screening, mail questionnaire survey was conducted in July 1987. The questionnaire sent to 950 health screening institutions. and 700 enterprises in whole land but they were returned from 254 health istitutions and 187 enterprises, which were analyzed. The results were as follows: 1) The attitude of the respondents toward the necessity and benefit of the periodic health screening was showed highly positive responses in both of screening institutions and enterprises, and it was more positive in screening institutions. The attitude toward the affirmative and the contentment was showed less positive than that of the necessity and benefit. 2) The respondent recognized may problems on regard to the screening programme. The health screening institutions lie in the state of competition with other institutions for undertaking the screening programme. 3) One of major complaints from enterprises was the lack of sincerity in performing the screening programme. They wanted more practical and reliable health screening examination rather than showy one. 4) Health screening institutions and enterprises showed some mutual contradictions in the matter of screening fee, and so the screening fee should be adjusted to the appropriate cost.

• Journal of Welding and Joining
• /
• v.32 no.3
• /
• pp.68-73
• /
• 2014

Among through silicon via (TSV) technologies, for replacing Cu filling method, the method of molten solder filling has been proposed to reduce filling cost and filling time. However, because Sn alloy which has a high coefficient of thermal expansion (CTE) than Cu, CTE mismatch between Si and molten solder induced higher thermal stress than Cu filling method. This thermal stress can deteriorate reliability of TSV by forming defects like void, crack and so on. Therefore, we fabricated SiC composite filling material which had a low CTE for reducing thermal stress in TSV. To add SiC nano particles to molten solder, ball-typed SiC clusters, which were formed with Sn powders and SiC nano particles by ball mill process, put into molten Sn and then, nano particle-dispersed SiC composite filling material was produced. In the case of 1 wt.% of SiC particle, the CTE showed a lowest value which was a $14.8ppm/^{\circ}C$ and this value was lower than CTE of Cu. Up to 1 wt.% of SiC particle, Young's modulus increased as wt.% of SiC particle increased. And also, we observed cross-sectioned TSV which was filled with 1 wt.% of SiC particle and we confirmed a possibility of SiC composite material as a TSV filling material.

• Structural Engineering and Mechanics
• /
• v.65 no.2
• /
• pp.129-139
• /
• 2018

Post-tensioning (PT) tendons are commonly used for the assembly of modularized concrete members, and tension is applied to the tendons during construction to facilitate the integrated behavior of the members. However, the tension in a PT tendon decreases over time due to steel corrosion and concrete creep, and consequently, the stress on the anchor head that secures the PT tendon also diminishes. This study proposes an automatic detection system to identify tension reduction in a PT tendon using pulsed-eddy-current (PEC) measurement. An eddy-current sensor is installed on the surface of the steel anchor head. The sensor creates a pulsed excitation to the driving coil and measures the resulting PEC response using the pick-up coil. The basic premise is that the tension reduction of a PT tendon results in stress reduction on the anchor head surface and a change in the PEC intensity measured by the pick-up coil. Thus, PEC measurement is used to detect the reduction of the anchor head stress and consequently the reduction of the PT tendon force below a certain threshold value. The advantages of the proposed PEC-based tension-reduction-detection (PTRD) system are (1) a low-cost (< $ 30), low-power (< 2 Watts) sensor, (2) a short inspection time (< 10 seconds), (3) high reliability and (4) the potential for embedded sensing. A 3.3 m long full-scale monostrand PT tendon was used to evaluate the performance of the proposed PTRD system. The PT tendon was tensioned to 180 kN using a custom universal tensile machine, and the tension was decreased to 0 kN at 20 kN intervals. At each tension, the PEC responses were measured, and tension reduction was successfully detected.

• The Journal of the Korea Contents Association
• /
• v.12 no.1
• /
• pp.508-515
• /
• 2012

The purpose of this study was to examine if factors of baseball stadium environment which people have spectating satisfaction of professional baseball. The respondents of the study 614 who were spectators at D city professional baseball event. The stratified cluster random sampling method has been used in this study. The material collection device was the brochure named [A Influence of Factors of Baseball Stadium Environment on Spectating Satisfaction of Professional Baseball]. The result of reliability check up was here below; stadium factors ${\alpha}$=.966~.890, spectating costs ${\alpha}$=.922~.988, spectating promotion ${\alpha}$=.894~.789. To analyze materials, the "correlation analysis" and "regression analysis" were used as statistic analysis techniques. The conclusion based on above study method and the result of material analysis are here below. 1. The stadium factors influence spectating satisfaction of professional baseball. 2. The spectating cost factors influence spectating satisfaction of professional baseball. 3. The spectating promotion factors influence spectating satisfaction of professional baseball.

• Journal of KIISE:Software and Applications
• /
• v.36 no.7
• /
• pp.523-530
• /
• 2009

Despite the growing need for customized operating system kernels for embedded devices, kernel development continues to suffer from insufficient reliability and high testing cost for several reasons such as the high complexity of the kernel code. To alleviate these difficulties, this study proposes the MOdel-based KERnel Testing (MOKERT) framework for detection of concurrency bugs in the kernel. MOKERT translates a given C program into a corresponding Promela model, and then tries to find a counter example with regard to a given requirement property, If found, MOKERT executes that counter example on the real kernel code to check whether the counter example is a false alarm or not, The MOKERT framework was applied to the Linux proc file system and confirmed that the bug reported in a ChangeLog actually caused a data race problem, In addition, a new data race bug in the Linux proc file system was found, which causes kernel panic.

• The Journal of Society for e-Business Studies
• /
• v.22 no.4
• /
• pp.39-51
• /
• 2017

In October 2016, the NFSA (National Financial Supervisory Authorities) revised the network separation clause of the Regulation on Supervision of Electronic Financial Activities in order to promote the Cloud Computing implementation in the financial sectors. The new regulation, however, limits the Cloud Computing usage to non-critical information and its processing system. Financial institutions that provide customer data analysis and personalized services based on personal data regard current revision as unchanged as before. The implementation of Cloud Computing has greatly contributed to cost reduction, business innovation and is an essential requirement in ever-changing information communication technology environment. To guarantee both security and reliability of the implementation of the Cloud Computing in financial sectors, a considerable amount of research and debate needs to be done. This paper examines current Cloud Computing policies in the Korean financial sector and the challenges associated with it. Finally, the paper identifies policy suggestions based on both European Union and United States' approach as they have successfully introduced Cloud Computing Services for their financial sectors.