• Nuclear Engineering and Technology
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• v.49 no.2
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• pp.286-294
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• 2017

The events at the Fukushima Daiichi Nuclear Power Station in March 2011 point out, among other matters, that concurrent accidents at multiple units of a site can occur in reality. Although site risk has been deterministically considered to some extent in nuclear power plant siting and design, potential occurrence of multi-unit accident sequences at a site was not investigated in sufficient detail thus far in the nuclear power community. Therefore, there is considerable worldwide interest and research effort directed toward multi-unit site risk assessment, especially in the countries with high-density nuclear-power-plant sites such as Korea. As the technique of probabilistic safety assessment (PSA) has been successfully applied to evaluate the risk associated with operation of nuclear power plants in the past several decades, the PSA having primarily focused on single-unit risks is now being extended to the multi-unit PSA. In this paper we first characterize the site risk with explicit consideration of the risk associated with spent fuel pools as well as the reactor risks. The status of multi-unit risk assessment is discussed next, followed by a description of the emerging issues relevant to the multi-unit risk evaluation from a practical standpoint.

• Korean Journal of Social Welfare
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• v.61 no.4
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• pp.85-108
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• 2009

The quickening pace of international migration in the last twenty years brought fundamental demographic and social changes to the Korean society. Increasing number of marriage-based immigrant families imposes new challenges on social work community; however, the social work community has not been equipped with necessary practice models, sets of skills and professionals with cultural competency. This study aims to explore an integrative framework of social work practice with this client group. Research foci include the profile of marriage-based immigrant families in Korea, available social services at the time, challenges and issues they face, the compatibility of the empowerment based social work practice, and micro/mezzo/macro level concerns that arise for the effective service provision. Challenges among marriage-based immigrant families are converged into personal/familial, community related, and larger social-cultural issues. Empowerment is a multi-dimensional social process to help people gain control over their lives; a process that fosters power in people, for use in their lives, their communities and in their society. Empowerment based social work practice can be the most competent framework for working with multi-cultural families considering their multi-faceted acculturation issues while they navigate thru Korean society. Issues of educating and training of culturally competent social workers are discussed.

• Nuclear Engineering and Technology
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• v.41 no.3
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• pp.225-236
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• 2009

This study has identified human performance research issues associated with the implementation of new technology in nuclear power plants (NPPs). To identify the research issues, current industry developments and trends were evaluated in the areas of reactor technology, instrumentation and control technology, human-system integration technology, and human factors engineering (HFE) methods and tools. The issues were prioritized into four categories based on evaluations provided by 14 independent subject matter experts representing vendors, utilities, research organizations and regulators. Twenty issues were categorized into the top priority category. The study also identifies the priority of each issue and the rationale for those in the top priority category. The top priority issues were then organized into research program areas of: New Concepts of Operation using Multi-agent Teams, Human-system Interface Design, Complexity Issues in Advanced Systems, Operating Experience of New and Modernized Plants, and HFE Methods and Tools. The results can serve as input to the development of a long-term strategy and plan for addressing human performance in these areas to support the safe operation of new NPPs.

• Journal of Broadcast Engineering
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• v.11 no.4 s.33
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• pp.458-470
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• 2006

This paper describes issues and consideration on authoring of interactive multi-view visual content based on MPEG-4. The issues include types of multi-view visual content; scene composition for rendering; functionalities for user-interaction; and multi-view visual content file format. The MPEG-4 standard, which aims to provide an object based audiovisual coding tool, has been developed to address the emerging needs from communications, interactive broadcasting as well as from mixed service models resulting from technological convergence. Due to the feature of object based coding, the use of MPEG-4 can resolve the format diversity problem of multi-view visual contents while providing high interactivity to users. Throughout this paper, we will present which issues need to be determined and how they can be realized by means of MPEG-4 Systems.

• Korean Journal of Child Studies
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• v.30 no.6
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• pp.85-97
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• 2009

Korean society has been facing many challenges and promises resulting from the rapid population shifts into multi-cultural and multi-ethnic family composition. Government strived to respond to the impending demands and needs of Korean cultural families, in terms of marriage and birth, caring and educating children, and labor and work. This paper overviews the current state of Korean multicultural trends and facts in terms of family, marriage, children, and work. It also overarches major issues of multicultural studies of family relations and child development. By wrapping the facts and issues in current discourse and studies, pragmatic policy points were provided and condensed into some suggestions for the policy-making and program implementation.

• Nuclear Engineering and Technology
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• v.44 no.5
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• pp.437-452
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• 2012

The Tohoku earthquake (Mw9.0) occurred on March 11, 2011 and caused a large tsunami. The Fukushima Dai-ichi NPP (F1-NPP) were overwhelmed by the tsunami and core damage occurred. This paper describes the overview of F1-NPP accident and the usability of tsunami PRA at Tohoku earthquake. The paper makes reference to the following current issues: influence on seismic hazard of gigantic aftershocks and triggered earthquakes, concepts for evaluating core damage frequency considering common cause failure with correlation coefficient against seismic event at multi units and sites, and concepts of "seismic-tsunami PSA" considering a combination of seismic motion and tsunami effects.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.9
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• pp.210-221
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• 2000

Plastic mold designers and frequently faced with optimizing multi-quality issues in injection molded parts. These issues are usually in conflict with each other and thus tradeoff needs to be made to reach a final compromised solution. in this study an automated injection molding design methodology has been developed to optimize multi-quality characteristics of injection molded parts. The features of the proposed methodology are as follows : first utility theory is applied to transform the original multi-objective problem into single-objective problem. Second is an implementation of a direct search-based injection molding optimization procedure with automated consideration of robustness against process variation. The modified complex method is used as a general optimization tool in this study. The developed methodology was applied to an actual mold design and the results showed that the methodology was useful through the CAE simulation using a commercial injection molding software package. Applied to production this study will be of immense value to companies in reducing the product development time and enhancing the product quality.

• Journal of Arbitration Studies
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• v.9 no.1
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• pp.139-160
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• 1999

International commercial arbitrations have developed into a simple form in which both parties involved in the dispute by a contract intend to solve the dispute through the legal arbitration system. however nowadays the above traditional form taken by international projects are rarely seen and instead the form of complex arbitration in which many parties are involved has become more and more universal. The complex arbitration means not only many-sided parties concerned but also means a plural number of contract involved in conflicts, a plural number of issues involved in conflicts and a plural number of contracts though their contractors are not in a plural number. However in this report the complex arbitrations will be studied into categories as follows : 1. Pure multi-issue situations, 2. Pure multi-party situations, 3. Pure multi-contract situations. A Pure Multi-Issue arbitration basically includes a plural number of claims between the two parties concerned. A Pure Multi-party case classically presupposes an arbitration clause which involves a plural number of parties concerned. After Party A takes a legal proceeding and then Party B institutes a request to Party C in the above proceeding. In that case the problem arises on whether it is allowed to do so or not. A Pure Multi-Contract case presupposes that when Party A and Party B have independent arbitration clauses based on separate contract relations, respectively, the problem is whether both above-mentioned proceedings can be unified into one or not. As for the above-mentioned complex arbitration, though international treaties are being formed, including the WTO treaties, the NAFTA treaties, the Mercosur treaties and others, legal regulations and customs have not yet been formed domestically. The institutional preparations will be necessitated in consideration of national legal status as well as international treaty relations.

• Journal of Power Electronics
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• v.16 no.3
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• pp.946-959
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• 2016

A novel Virtual Space Vector (VSV) modulation strategy for complete control of potential neutral point (NP) issues is proposed in this paper. The neutral point potential balancing problems of multi-level converters, which include elimination of low frequency oscillations and self-balancing for NP dc unbalance, are investigated first. Then a set of improved virtual space vectors with dynamic adjustment factors are introduced and a multi-objective optimization algorithm which aims to optimize these adjustment factors is presented in this paper. The improved virtual space vectors and the multi-objective optimization algorithm constitute the novel Virtual Space Vector modulation. The proposed novel Virtual Space Vector modulation can simultaneously recover NP dc unbalance and eliminate low frequency oscillations of the neutral point. Experiment results show that the proposed strategy has excellent performance, and that both of the neutral point potential issues can be solved.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.10
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• pp.60-71
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• 2012

This paper proposes a new design and implementation of multi-protocol IED for networked control system of multi-induction motor in industrial fields. The experimental multi-induction motor based multi-protocol IED of Modbus/LonTalks/TCP/IP module is designed and fabricated. This article addresses issues in architecture of LonWorks/Ethernet sever, embedded processors architecture for converting Modbus protocol to LonTalks protocol, integrating preconfigured software, and Internet technologies. It is also verified that the multi-induction motor control and monitoring system using LonWorks/Ethernet server have available, interoperable, reliable performance characteristics from the experimental results, especially, the seamless integration of TCP/IP networks with control networks allows access to any control point from anywhere. Thus, the results provide available technical data for remote distributed motor control system of industrial field or building microgrid with LonWorks BAS.