• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.12 no.1
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• pp.1-10
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• 2016

The number of nuclear power plants operating in Korea was 24 as of year 2015. Nine units out of 24 units have been operated for a period over 20 years. Kori unit 1 has been in operation for 40 years, and an extended operation for Wolsong unit 1 was decided in 2015. There has been reported some crackings in reactor internals in PWR have been reported in Europe, USA, Japan and Korea, and some of them were replaced with new one. Repair and replacement technologies for the reactor internals have been developing in order to meet the regulatory requirements for long term operation in Korea. The technologies will also be used for the exported nuclear units. It is required to review degradation history of the reactor internals worldwide as a part of the degradation management program development. Schematics of reactor internals designed and supplied by Westinghouse, Framatome and Combustion Engineering are described herein. Materials degradation history of reactor internals of PWR plants in USA, Japan and Europe is surveyed and summarized. Some events from Korean plants are also described. Aging management strategy for the internals is suggested.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.5 no.2
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• pp.13-19
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• 2009

As the operating time in nuclear power plants (NPPs) increases, the integrity of nuclear components may be continually degraded due to aging effects of systems, structures and components. Recently, a number of NPPs are being operated beyond their design life to produce more electricity without shutting down. The critical issue in extending a lifetime is to maintain the level of safety during the extended operation period while satisfying the international regulatory standards. Therefore, it is beneficial to build a monitoring system to measure an aging status. In this paper, the Aging Monitor (AM) based on lots of aging database obtained from the operating plants and research results on the aging effects was developed to monitor, manage and evaluate the aging phenomena systematically and effectively in NPPs. The AM for the CANDU is divided into 6 modules: (1) Aging Alarm/Coloring Monitor, (2) Aging Database, (3) Aging Document, (4) Real-time Integrity Monitor, (5) Surveillance and Inspection Management System, and (6) Continued Operation and Periodic Safety Review (PSR) Safety Evaluation. The proposed system is expected to provide the integrity assessment for the major mechanical components of an NPP under concurrent working environments.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.161-164
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• 2008

It is played an important part in dam safety that KWATER is taken the responsibility of design, construction and maintenance about dam. It is considered that safety inspection of accumulated technology and knowledge of new evaluation method have developed. Thus this study is that instrumentation data is analyzed continually and dam's safety is evaluated about behavior property, in Chungju concrete dam. New evaluation method is that instrumentation data is analyzed reliability. It is suggested that suitability of management period and maintenance of instrument in dams.

• Proceedings of the Korea Database Society Conference
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• 2010.06a
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• pp.13-19
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• 2010

Information competitiveness accounts for substantial parts of business competitiveness necessary for business management in the knowledge-information society in the 21st century. To improve quality. productivity and competitiveness through information in the fields of SMEs particularly having difficulties under rapidly changing business environment. the government has operated "SME Information Support Project" for the past 8 years. The methodology for developing the standard for this project known as EISDM (Enterprise Information System Development Methodology) provides communication between IT businesses and SMEs participating in this project. and standardized output document formats and how to make out such documents. Infortunately. the number of personnel partaking in the development project for SMEs is no more than 2~4 per site on average. Further. they are required to complete demand analyses. development. testing and operation in about 6 months. which is a very short period. Moreover, there is too much demand for documentation, which is likely to end up being formal work process just for supervision and inspection. That is, the documentation could be for noting but documents. which will prove useless outputs after the project finishes. Therefore, this study proposes an improvement approach as an information system development methodology taking into account SMEs' characteristics and environment so as to relieve developers from such excessive burden of documentation, to save time and resources through efficient management of software development as the original purpose of the methodology, and to produce required quality software.

• Current Photovoltaic Research
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• v.2 no.2
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• pp.63-68
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• 2014

In recent years, discoloration defects, called as snail trail, have been observed at many crystalline photovoltaic modules after a period of time ranging from several months to several years after initial installation. It has been reported that this phenomenon doesn't impact on the performance of photovoltaic modules, but it can be detected through simple visual inspection. The origin and detailed mechanism for the formation have not been identified. In this study, non-destructive analysis by Raman spectroscopy has been carried out to investigate the origin of this phenomenon. In parallel, destructive analysis by scanning electron microscopt and transmission electron microscopy was also performed in order to confirm the results from non-destructive method. Through the extensive analysis, it was found that the main cause for discoloration is the formations of $Ag_2CO_3$ and $AgC_2H_3O_2$. Detailed mechanism for the formation of these particles was indentified through systematic studies.

• Journal of Animal Science and Technology
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• v.56 no.5
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• pp.19.1-19.6
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• 2014

The purpose of this study was to investigate crucial factors on HACCP system implementation in domestic livestock product plants, and to offer job satisfaction and the career prospect of HACCP system operators. The survey was carried out by selecting 150 HACCP system operators who implemented HACCP system. The respondents claimed that the most important contents in HACCP system operation were to assemble HACCP team (21.8%), and the second was to monitoring (20.0%). Documentation and recording (16.9%) and verification (11.1%) were followed. The respondents answered the major factor in sanitation management was cleaning/washing/disinfection (18.9%) and inspection (18.4%). The results showed that there were significant differences in the prospect of occupation in HACCP system operator by the gender (p < 0.015), age, livestock product facilities, service period, and position (p < 0.001). The respondents from HACCP system operator were satisfied with their job (73%) and also showed optimistic prospect of occupation (82%).

• Nuclear Engineering and Technology
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• v.47 no.3
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• pp.253-259
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• 2015

The fast neutron reactor BOR-60 is one of the key experimental facilities worldwide to perform large-scale tests of fuel, absorbing, and structural materials for advanced reactors. The BOR-60 reactor was put into operation in December 1969, and by the end of 2014 it had been operating on power for ~265,000 hours. BOR-60 still demonstrates potential capabilities to extend the lifetime of sodium-cooled fast reactors. The BOR-60 lifetime should have expired at the end of 2014. Over the past few years, a great scope of work has been performed to justify the possibility of extending its lifetime. The work included inspection of the equipment conditions, calculations and experimental research on operating parameters and the conditions of nonremovable components, investigation of the structural material samples after their long-term operation under irradiation, etc. Based on the results of the work performed, the residual lifetime was evaluated and the reactor operator made a decision to extend the lifetime period of the BOR-60 reactor. After considering both a set of documents about the reactor conditions and the positive decision of independent experts, the Regulatory Authority of the Russian Federation extended the BOR-60 operating license up to 2020.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1458-1465
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• 2008

With 34 years of accumulated operating experience, Seoul Metro has launched a project aimed at exporting second-hand trains(used EMU cars) to Vietnam while seeking measures for diversifying its business such as the construction of the metropolitan railways both at home and abroad, and operating business as a way of fiscal consolidation and management improvement. Therefore, Seoul Metro has moved ahead with this plan considering that there's no legal constraints on durable period of rolling stocks in advanced countries where the vehicles have been used for 35 years or longer than 40 years through renovation such as safety inspection and comprehensive maintenance program, and the railway systems for the replacement are expected to reach 838 cars by 2015 with growth of 100 cars a year. Seoul Metro strives to create value for boosting revenues and recycling resources by sending used EMUs to Vietnam. Seoul Metro will also provide under-developed countries with cars at a low price as well as share the accumulated railway technical know-how so that it can promote the national image and obtain the pre-emptive effect of metro railways in Vietnam.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.11
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• pp.303-314
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• 2020

This paper investigates the relationships between bank credit and trade credit with profit of 130 agricultural firms listed on Vietnam's stock exchanges during the period 2008-2014. Using the GMM approach, the paper reveals inverted-U shaped (∩) relationships between bank credit and trade credit with profit. Specifically, the optimal threshold of bank credit and trade credit to total assets of the firms are 0.4173 and 0.2425, respectively. The findings mean that if the ratio of bank credit to total assets exceeds the benchmark of 0.4173, firms should consider restructuring debts to get them back to the benchmark. To do so, firms should withdraw from those business fields that are not of their profession, in addition to liquiditizing unused assets to repay debts and not using short-term credit to invest in long-term projects. Firms may use trade credit wisely when other sources of finance are lacking. In concrete terms, firms can increase trade credit use if the ratio of trade credit to total assets is below 0.2425. Yet, if this ratio goes beyond this benchmark, firms should get back to this benchmark, e.g., keeping a suitable amount of inventory. The implications of this study is to boost firm growth in the proposed way.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.10
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• pp.43-50
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• 2020

Disclosure level in interim financial reporting is important for information users to make business decisions. This has received much attention from the information users. The article is aimed at determining the factors of financial ratios, which impact on the disclosure level in interim financial reporting. The authors use the ordinary least squares to test. The sample consists of 418 VN100 over a 6-year period from 2014 to 2019. The results show that there are four factors that positively impact on the disclosure level in interim financial reporting: Enterprise size (SIZE); Liquidity (LIQI); Sales growth (GROW) and Profitability (ROE). The article proposes some policy recommendations to contribute to improving disclosure level in interim financial reporting. Accordingly, State Securities Commission of Vietnam should strengthen the regular inspection of VN100's disclosure level in interim financial reporting and also should enforce strict sanctions or may consider delisting in cases of listed enterprises with incomplete disclosure. The managers of VN100 need to raise the sense of responsibility of information providers to ensure adequate information in interim financial reporting. Investors should also pay attention to the financial ratios of VN100 such as firm size, return-on-equity, liquidity, and sales growth to get useful information and ensure sound business decisions.