• Nuclear Engineering and Technology
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• v.53 no.2
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• pp.677-687
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• 2021

The tendency to renewables is one of the consequences of changing attitudes towards energy issues. As a result, solar energy, which is the leader among renewable energies based on availability and potential, plays a crucial role in full filing global needs. Significant problems with the solar thermal power plants (STPP) are the operation time, which is limited by daylight and is approximately half of the power plants with fossil fuels, and the capital cost. Exergy analysis survey of STPP hybrid with PCM storage carried out using Engineering Equation Solver (EES) program with genetic algorithm (GA) for three different scenarios, based on eight decision variables, which led us to decrease final product cost (electricity) in optimized scenario up to 30% compare to base case scenario from 28.99 $/kWh to 20.27 $/kWh for the case study. Also, in the optimal third scenario of this plant, the inner carbon dioxide gas cycle produces 1200 kW power with a thermal efficiency of 59% and also 1000 m3/h water with an exergy efficiency of 23.4% and 79.70 kg/h with an overall exergy efficiency of 34% is produced in the tetrageneration plant.

• The Journal of Information Systems
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• v.31 no.4
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• pp.47-73
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• 2022

Purpose The purpose of this study is to select the electronic architecture concept of the powertrain domain of the electronic platform to be applied to electric vehicles after 2025. Previously, the automotive electrical and electronic architecture was determined only by trend analysis, but the purpose was to determine the scenario based on the data and select it with clear evaluation indicators. Design/methodology/approach This study identified the function to be applied to the powertrain domain of next-generation electric vehicle, estimated the controller, defined the function feature list, organized the scenario candidates with the controller list and function feature list, and selected the final architecture scenario. Findings According to the research results, the powertrain domain of electric vehicles was selected as the architectural concept to apply the DCU (Domain Control Unit) and VCU (Vehicle Control Unit) integrated architecture to next-generation electric vehicles. Although it is disadvantageous or equivalent in terms of cost, it was found to be excellent in most indicators such as stability, security, and hardware demand.

• Journal of the military operations research society of Korea
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• v.37 no.1
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• pp.119-128
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• 2011

This paper deals with a study on mission analysis considering the effectiveness measurement of UAV system operations. This mission analysis process is composed of 5 steps; (1) creation of a base model in MANA, (2) design of input parameter set using experiment design, (3) mapping input parameter set to the MANA scenario file, (4) data farming and model run in batch process, and (5) statistical analysis of the simulation result. In the result of this study, the effect of input parameter to the dependent parameter was shown to decrease in the order classification range, sweep width, height, speed, FOV(Field of view), and classification probability. The study also shows that the operational effectiveness of an improved scenario proposed can increase 10.2% from the base scenario.

• Journal of the Korea Convergence Society
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• v.8 no.11
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• pp.77-83
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• 2017

For efficient predictive analysis, self-healing research is needed that enables the system to recover autonomously by self-cognition and diagnosing system problems. However, software development does not provide formal contextual information analysis and appropriate presentation structure according to external situation. In this paper, we propose a prediction analysis method based on the change contents by applying the extraction rule to the functions that can act, data, and transaction based on the new Goal-scenario. We also evaluated how well the predictive analysis met through the performance indicators for achieving the requirements goal. Compared with the existing methods, the proposed method has a maximum 32.8% higher matching result through performance measurement, resulting in a 28.9% error rate and a 45.8% reduction in the change code. This shows that it can be processed into a serviceable form through rules, and it shows that performance can be expanded through predictive analysis of changes.

• Tunnel and Underground Space
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• v.27 no.2
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• pp.89-99
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• 2017

For a successful performance of Carbon Capture Sequestration (CCS) projects, appropriate injection conditions should be designed to be optimized for site specific geological conditions. In this study, we built a simple 2-dimensional analysis model, based on the geology of Jang-gi basin which is one of the potential sites of domestic CCS projects. We evaluated the impact of initial stress conditions and injection rate through coupled TOUGH-FLAC simulator. From the preliminary analysis, we constructed risk scenarios with the higher potential of shear slip and performed scenario analysis. Our analysis showed that normal stress regime produced the highest potential of shear slip and stepwise increasing injection rate scenario resulted in much larger pore pressure build up and consequent higher potential of the shear slip, which was evaluated using a mobilized friction coefficient.

• Korean Journal of Community Nutrition
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• v.8 no.4
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• pp.556-565
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• 2003

Market segmentation helps providers to find better marketing opportunities and allows foodservice managers to develop the right product for each target market. Therefore, this study, taking university faculty and staff as subject, is intended to diagnose the relative value of service quality attribute, on the basis service quality scenario of faculty foodservice; to suggest price for improving customer loyalty in market segments. A questionnaire was developed ar d mailed to 600 Yonsei university faculty and staffs. A total of 385 questionnaires were usable; resulting in a 58.7％ of faculty and a 69.7％ of staff response rate, respectively. Statistical data analysis was completed using the SAS/Win 6.12 for descriptive Analysis, ANOVA, principal factor analysis, cluster analysis, reliability test and discriminant analysis. The results of the study are as below. Eighteen questions were selected for measuring respondents' lifestyle by AIO method and the seven lifestyle factors derived from factor analysis and aggregated distinct 4 clusters. Service quality attributes of the scenario were determined with 'food quality', 'menu variety', 'atmosphere', 'fast service', and 'clean and sanitation'. 'Food quality', 'menu variety', 'atmosphere', 'fast service', and 'clean and sanitation', in decreasing order, were identified as improving customer loyalty. However, most faculty and staffs were satisfied with the present meal price. The result of this study indicates that the relative value of service quality was differed significantly among the various market segments. 'Food quality', 'menu variety', and 'atmosphere' were determined as major service quality attributes. Thus, customer loyalty could be increased by improving food taste and quality, atmosphere, and service delivery. (Korean J Community Nutrition 8(4) : 556 ∼565, 2003)

• Nuclear Engineering and Technology
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• v.41 no.7
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• pp.945-952
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• 2009

The Three Mile Island Unit 2 (TMI-2) accident provides unique full scale data, thus providing opportunities to check the capability of codes to model overall plant behavior and to perform a spectrum of sensitivity and uncertainty calculations. As part of the TMI-2 analysis benchmark exercise sponsored by the Organization for Economic Cooperation and Development Nuclear Energy Agency (OECD NEA), several member countries are continuing to improve their system analysis codes using the TMI-2 data. The Republic of Korea joined this benchmark exercise in November 2005. Seoul National University has analyzed the TMI-2 accident as well as the currently proposed alternative scenario along with a sensitivity study using the Modular Accident Analysis Program Version 4.03 (MAAP4.03) code in collaboration with the Korea Hydro and Nuclear Power Company. Two input files are required to simulate the TMI-2 accident with MAAP4: the parameter file and an input deck. The user inputs various parameters, such as volumes or masses, for each component. The parameter file contains the information on TMI-2 relevant to the plant geometry, system performance, controls, and initial conditions used to perform these benchmark calculations. The input deck defines the operator actions and boundary conditions during the course of the accident. The TMI-2 accident analysis provided good estimates of the accident output data compared with the OECD TMI-2 standard reference. The alternative scenario has proposed the initial event as a loss of main feed water and a small break on the hot leg. Analysis is in progress along with a sensitivity study concerning the break size and elevation.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.04a
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• pp.387-392
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• 2003

• Proceedings of the Korean Nuclear Society Conference
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• 2005.05a
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• pp.283-284
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• 2005

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2019.05a
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• pp.375-376
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• 2019