• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.380-383
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• 2003

In this paper, we propose a fuzzy group decision making method for multiple decision maker-multiple objective programming problems to obtain the agreeable solution. In the proposed method, considering the vague nature of human subjective judgement it is assumed that each of multiple decision makers has a fuzzy goal for each of his/her own objective functions. After eliciting the membership functions from the decision makers for their fuzzy goals, total M-Pareto optimal solution concept is defined in membership spaces in order to deal with multiple decision maker-multiple objective programming problems. For generating a candidate of the agreeable solution which is total M-Pareto optimal, the extended weighted minimax problem is formulated and solved for some weighting vector which is specified by the decision makers in their subjective manner, Given the total M-Pareto optimal solution, each of the derision makers must either be satisfied with the current values of the membership functions, or update his/her weighting vector, However, in general, it seems to be very difficult to find the agreeable solution with which all of the decision makers are satisfied perfectly because of the conflicts between their membership functions. In the proposed method, each of the decision makers is requested to estimate the degree of satisfaction for the candidate of the agreeable solution. Using the estimated values or satisfaction of each of the decision makers, the core concept is desnfied, which is a set of undominated candidates. The interactive algorithm is developed to obtain the agreeable solution which satisfies core conditions.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.689-692
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• 1996

The environment surrounded by industries is represented by the 3Cs : Customers, Competition, and Changes. The 3Cs drive industries to pursue external business targets such as customer's needs and marketplaces with BPR (Business Process Reengineering). BPR addresses core business process. One of these core business processes is product development. This product development process has been reengineered by the concept of CE (Concurrent Engineering). The aim of the paper is to build frameworks of CE to clarify the CE concept. This paper begins with investigating the product development process from the perspectives of three drivers: cost, quality and speed. CE frameworks are then followed. The first frmework is concerned with the CE definition and thus three keyphrases are extracted : from the outset, concurrent design and systematic approach. Concerned with the CE implementation, the second framework is composed of five components: generalist & specialist, cross-function team, enabling tools & techniques, success metrics, and total visibility. This paper concludes that the CE practice is hard to achieve because of the 'dont't-tell-them-early' attitude of upstream people, and the 'wait-and-see' attitude of downstream people. As resolution, a change management program is recommended that changes an employees mind-set. This paper also supposes computer systems which facilitate and keep automatic track of the CE process as engineered. Finally it gives a warning that computer systems alone do not guarantee success without being preceded by process re-engineering.

• Journal of Communications and Networks
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• v.2 no.1
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• pp.35-45
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• 2000

this paper presents the concept of "mobile ATM', a proposal for third-generation (3G) mobile communication network infrastructure capable of supporting flexible evolution of radio technologies from today's cellular and data services towards future wireless multimedia services. Mobile ATM provides generic mobility management and QoS-based transport capabilities suitable for integration of multiple radio access technologies including cellular voice. wireless data, and future broadband wireless services. The architecture of a mobile ATM network is outlined in terms of the newly-defined "W-UNI" interface at the radio link and "M-UNI"and "M-UNI" interface which supports unified access for WATM and non-ATM mobile terminals through corresponding interworking functions (IWF) is explained. leading to an understanding of how different radio access technologies are supported by the same ATM-based core network infrastructure. Generic mechanisms for handoff and location management within the core mobile network are discussed. and related protocol extensions over the "W-UNI" and "M-UNI/NNI"interfaces are proposed. the issue of "crossover switch (COS)" selection in mobile ATM is considered, and a unified handoff signaling syntax which supports flexibility in COS selection is described. Typical signaling sequences for call connection and handoff using the proposed protocols are outlined. Experimental results form a proof-of-concept mobile ATM network prototype are presented in conclusion.

• Nuclear Engineering and Technology
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• v.48 no.4
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• pp.893-905
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• 2016

Numerous advanced reactor concepts have been proposed to replace light water reactors ever since their establishment as the dominant technology for nuclear energy production. While most designs seek to improve cost competitiveness and safety, the implausibility of doing so with affordable materials or existing nuclear fuel infrastructure reduces the possibility of near-term deployment, especially in developing countries. The organic nuclear concept, first explored in the 1950s, offers an attractive alternative to advanced reactor designs being considered. The advent of high temperature fluids, along with advances in hydrocracking and reforming technologies driven by the oil and gas industries, make the organic concept even more viable today. We present a simple, cost-effective, and safe small modular nuclear reactor for offshore underwater deployment. The core is moderated by graphite, zirconium hydride, and organic fluid while cooled by the organic fluid. The organic coolant enables operation near atmospheric pressure and use of plain carbon steel for the reactor tank and primary coolant piping system. The core is designed to mitigate the coolant degradation seen in early organic reactors. Overall, the design provides a power density of 40 kW/L, while reducing the reactor hull size by 40% compared with a pressurized water reactor while significantly reducing capital plant costs.

• Asia pacific journal of information systems
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• v.13 no.3
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• pp.1-21
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• 2003

Facing competitive and complicated business environment, many companies are developing new and diverse organization forms not only to overcome to minimize costs and risks but also to maximize the efficiency of an organization. Virtual organization is one of the representative forms allowing firms to create this value though a link of core competency among firms. In order to explain the performance of virtual organization in terms of efficiency, this study utilizes a concept of trust since it is recently considered as one of core concept to enhance the cooperative performance between firms and also virtual organizations success or failure can not be properly explained by traditional transaction-cost based economic point of view. Based on previous literature this study derives three success factors, organizational reputation, skill Uniqueness, and interpersonal trust and studies how three factors influence on the efficiency of virtual organization. Findings conducted with a questionnaire survey are as follow: first, organization reputation and skill uniqueness between virtual organization's transaction parties are important elements in the success of virtual organization. Second, interpersonal trust affected by organization reputation and skill uniqueness decides virtual organization's efficiency.

• Journal of international Conference on Electrical Machines and Systems
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• v.1 no.1
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• pp.47-53
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• 2012

A novel 6/5 switched reluctance motor (SRM) with short flux path is presented in this paper. The concept of this proposed motor is a novel SR motor with six stator and five rotor poles. The stator is constructed with three independent and physically separate C-core segments, and the rotor is composed of five poles. This motor, with a new selection for the number of stator/rotor poles, achieves a short flux path, which reduces the magnetomotive force required to drive the motor. To verify the performance of the proposed motor, a comparison with conventional SR motors with the same dimensions is executed. The comparison demonstrates that the proposed motor offers better performance in terms of maximum torque production. Furthermore, Finite Element Analysis (FEA) and Matlab/Simulink software are used to predict and simulate the performance of the proposed motor.

• Nuclear Engineering and Technology
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• v.26 no.2
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• pp.161-167
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• 1994

This paper presents a concept of a pressure tube-type water-cooled reactor without the emergency core cooling system. It adopts an innovative fuel channel design using metallic fuel matrix to improve heat transfer from fuel to moderator at loss of coolant cooling. The heat produced in the fuel is cooled by the coolant system during normal operation, but by the passive moderator system at loss of coolant cooling including the loss-of-coolant accident(LOCA). Simple analysis shows that the fuel channel temperature can be maintained within the permissible range for both normal operation and a complete LOCA.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.14 no.2
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• pp.49-58
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• 2018

The regulatory periodic inspection program (PSI) conducted at every overhaul period is the most important process for confirming the safety of nuclear power plants. The PSI for operating nuclear power plants in Korea mainly consist of component level performance check that had been developed based on deterministic approach putting the same degree of importance to all the inspection items. This inspection methodology is likely to be effective for preoperational inspection. However, once the plant is put into service, the PSI must be focused on whether to minimize the risk of accident using defense-in-depth concept and risk insight. The incorporation of defense-in-depth concept and risk insight into the deterministic based safety inspection has not been well studied so far. In this study, two track approaches are proposed to make sure that core damage be avoided: one is to secure success path and the other to block the failure path in a specific event tree of PSA. The investigation shows how to select safety important components and how to set up inspection group to ensure that core damage would not occur for a given initiating event, which results in strengthening defense-in-depth level 3.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.4_2
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• pp.673-686
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• 2022

Recently, as the importance of eco-friendly energy has increased hydrogen gas is in the spotlight as future energy. Due to its special properties, hydrogen gas is more difficult to detect requiring more precise sensing technology. The primary objective of this study is to design a concept of an underground hydrogen pipeline monitoring system. For this, the following research works are conducted sequentially; 1)selection of core technology for conceptual design, 2)state-of-the-art review, 3)design of a concept of the system. As a result, DAS(Distributed Acoustic Sensing), and DTS(Distributed Temperature Sensing) are selected as each core technology. Furthermore, a conceptual design of an underground hydrogen pipeline monitoring system is deducted. It is expected that the impact on the eco-friendly energy industry will be enormous due to the increasing interest in using hydrogen energy.

• Korean Journal of Social Welfare Studies
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• v.49 no.1
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• pp.163-190
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• 2018

The citizen-initiative has been frequently mentioned in community building project which is being promoted by Seoul City. The citizen-initiative has become an important concept in the direction of community welfare efforts. However, this concept has not been defined clearly in social welfare. In this context, the purpose of this study is to find how the practitioners of the social welfare practice field recognize the concept of citizen-initiative. In this study, concept mapping method was used to generate 59 statements about the citizeninitiative in 10 social workers in Seoul. Multidimensional scaling analysis and hierarchical cluster analysis are used to do mapping and grouping the 59 statements. The results are as follows. A total of 6 categories were derived. The six categories are named "Inducement of Participation", "Practice", "Procedure", "Awareness and Interest extension", "Expression of Opinion", "Attitude and Emotion". "Practice" category was revealed as a core category in the concept of citizen-initiative. This study is meaningful as a first step to discuss "what is the citizen-initiative?" and to make consensus in social welfare academic area and practice field.