• Fire Science and Engineering
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• v.20 no.4 s.64
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• pp.98-104
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• 2006

The Fire Protection Regulatory documents require the fire-resistive rating of fire barrier penetration seals be same as that of fire barriers. Pilot application of penetration seal evaluation for K nuclear plant, built before penetration seal requirements were made, was done. In this evaluation, visual inspection and estimating fire rating by comparing installed configuration with tested configuration of penetration seals, called bounding approach method, were applied. Further improvements for retrofit and maintenance are recommended with penetration seal evaluation results also. The practical use of the methodology adopted in this study and the evaluation result of K nuclear plant will be anticipated for other plant's penetration seal evaluation.

• Journal of the Korean Society of Safety
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• v.36 no.2
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• pp.111-119
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• 2021

Multi-dimensional analysis of reactor safety-KINS standard (MARS-KS) is a thermal-hydraulic code to simulate multiple design basis accidents in reactors. The code has been essential to assess nuclear safety, but has mainly focused on light water reactors, which are in the majority in South Korea. Few previous studies considered pressurized heavy water reactor (PHWR) applications. To verify the code applicability for PHWRs, it is necessary to develop MARS-KS input decks under various transient conditions. This study proposes an input model to simulate small-break loss of coolant accidents for PHWRs. The input model includes major equipment and experimental conditions for test B9802. Calculation results for selected variables during steady-state closely follow test data within ±4%. We adopted the Henry-Fauske model to simulate break flow, with coefficients having similar trends to integrated break mass and trip time for the power supply. Transient calculation results for major thermal-hydraulic factors showed good agreement with experimental data, but further study is required to analyze heat transfer and void condensation inside steam generator u-tubes.

• Journal of the Korean Institute of Gas
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• v.24 no.6
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• pp.83-90
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• 2020

This study conducted a risk assessment using the HyKoRAM program created by international joint research. Risk assessment was conducted based on accident scenarios and worst-case scenarios that could occur in the facility, reflecting design specifications of major facilities and components such as compressors, storage tanks, and hydrogen pipes in the hydrogen charging station, and environmental conditions around the demonstration complex. By identifying potential risks of hydrogen charging stations, we are going to derive the worst leakage, fire, explosion, and accident scenarios that can occur in hydrogen storage tanks, treatment facilities, storage facilities, and analyze the possibility of accidents and the effects of damage on human bodies and surrounding facilities to review safety.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.10 no.2
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• pp.17-25
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• 2015

This research is to analyze the mediating effect of corporate reputation between the organizational slack and corporate performance in venture SMEs. That is, after controlling the firm size, firm age, social capital, environmental uncertainty, we test three hypothesis. First, we test the hypothesis that organizational slack has a positive effect on corporate reputation. Second, we test the hypothesis that corporate reputation has a positive effect on corporate performance. Third, we test the positive mediating role of corporate reputation between organizational slack and corporate performance. For this research, we administered the questionnaire surveys, and got the 250 effective data(companies) of korean venture SMEs. We use SPSS 18.0, and analysis the validity, reliability, correlation and multiple regression analysis of research model. As a result, we can find the three meaningful results. First, organizational slack, especially not absorbed slack but unabsorbed slack, has positive effect on the corporate reputation. Second, corporate reputation has positive effect on corporate performance. Third, corporate reputation has mediating effect between organizational slack, especially not absorbed slack but unabsorbed slack, and corporate performance. Although this research has some limitations of generalization because of the limited size of samples, we has meaning information related to the venture companies in the academic and business field.

• Plant Journal
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• v.18 no.4
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• pp.58-65
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• 2023

In this study, to increase the methane content of biogas supplied from Nanji Water Regeneration Center and to purify impurities, a three-stage membrane purification process was designed and installed to demonstrate operation. The methane concentration of biomethane produced in the 2 Nm3/h purification process was set to three cases: 95%, 96.5%, and 98%, and the membrane area ratio of the membrane was 1:1, 1:2, 1:1:1, The optimum conditions for the membrane area of the separator were derived by changing to five of 1:2:1 and 1:2:2. 3 stage separation membrane process of 30 Nm3/h was installed to reflect the optimum condition of 2 Nm3/h, and biomethane production of 98% or more of methane concentration was demonstrated. As a result of the operation of the 2 Nm³/h refining device, the methane recovery rate at the 98% methane concentration was 95.6% when the membrane area ratio was 1:1 as the result of the two-stage operation of the separator, and the recovery rate of methane at 1:2 was increased to 96.8%. The methane recovery rate of the membrane three-stage operation was highest at 96.8% when the membrane area ratio was operated at 1:2:1. The carbon dioxide removal rate was 16.4 to 96.4% and the 2:2 to 95.7% film area ratio in the two-step process. In the three-step process, the film area ratio was 1:2:1 to 95.4%, and the two-step process showed higher results than the three-step process. In the 30 Nm3/h scale biogas purification demonstration operation, the methane concentration after purification was 98%, the recovery rate of methane was 97.1%, the removal rate of carbon dioxide was 95.7%, and hydrogen sulfide, the cause of corrosion, was not detected, and the membrane area ratio was 1:2:1 demonstration operation, biomethane production with a methane concentration of 98% or higher was possible.

• Korean Journal of Construction Engineering and Management
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• v.23 no.1
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• pp.98-105
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• 2022

It is essential for vertical smart farms that artificially grow crops in an enclosed space to properly utilize air environment facilities to create an appropriate growth environment. However, domestic vertical smart farm companies are creating a growing environment by relying on empirical data rather than systematic methods. Using IoT to create a growing environment based on systematic and precise monitoring can increase crop production yield and maximize profitability. This study aims to construct a monitoring system using IoT and to analyze the cause by demonstrating the imbalance of temperature environment, which is a significant factor in crop cultivation. 1) The horizontal temperature distribution of the multi-layer shelf was measured with different operating methods of LED and air conditioner. As a result, there was a temperature difference of "up to 1.7℃" between the sensors. 2) As a result of measuring the vertical temperature distribution, the temperature difference was "up to 6.3℃". In order to reduce this temperature gap, a strategy for proper arrangement and operation of air conditioning equipment is required.

• Information Systems Review
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• v.16 no.2
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• pp.77-95
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• 2014

From the success of TDX and CDMA to today's social media boom, Korea's ICT has achieved an amazing growth for the last couple of decades. However, in spite of ICT's role as an engine of growth in Korea, there have been concerns that ICT growth would negatively affect national employment due to the labor substitution effect. While some scholars insist that ICT would positively affect employment because it will enlarge the size of industry itself, many people blame ICT as a main culprit of rising unemployment rates. In this study, we try to empirically find the true effect of ICT growth on employment in Korea. We use the data of ICT productions, ICT investments, and various industries employments from 1995 to 2011. The methodologies we adopted for this study is Granger causality tests and impulse response functions based on vector autoregression (VAR) model. We find that ICT has negative impact on service industries, while it has positive impact on manufacturing industries. Meanwhile, ICT has no statistically significant impact on ICT industry itself. Since the impacts of ICT on employment are mixed, we can argue that ICT should not be blamed for the main cause of low employment. We suggest a direction of future policies to utilize ICT for vitalizing employments in Korea.

• Environmental and Resource Economics Review
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• v.16 no.3
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• pp.485-510
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• 2007

The purpose of this paper is to empirically analyze the economic effect of energy saving investment on the improvement of energy intensity. The data used in this paper are panel data, both time-series and cross-section data. In addition, eight manufacturing sectors has been divided into two groups: massive energy consuming (four industries) and non-massive energy consuming (four industries) ones and the time period of analysis is from 1982 to 2004. According to the empirical results, firstly, energy saving investment has a negative relationship with energy intensity, however, its effect is not high in terms of absolute volume of energy consuming. Secondly, in improving energy intensity of energy saving investment, its elasticity IS higher in non-massive energy consuming sector compared it with massive energy consuming sector. Thirdly, automation investment is also playing an important role in energy conservation. The elasticities of automation investment to energy intensity are larger than those of energy saving investment. In terms of the reduction of greenhouse gas per investment unit cost, however, energy saving investment has larger effect than automation investment.

• Fire Science and Engineering
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• v.24 no.4
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• pp.62-68
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• 2010

The present study purposed to develop the water mist package system for the cultural properties fire prevention and fire suppression system through analyzing fire protection system and cultural property's characteristic, and to suggest directions for the development of cultural property fire prevention system in the future. Maximum safety with minimum damage has issued a main objective in fire protection of the cultural property in Korea. Two types of the water mist nozzles having a low pressure had been developed by KEI. The one is for inside using in wooden cultural properties, the flow rate is 30~35 l/min and the discharging pressure is 13~14 bar. The other one is for out-side of wooden properties, the flow rate is 25~30 l/min and the discharging pressure is 14~15 bar. To evaluate the nozzles performance test, we made the fire scenario and full-scale model of wooden cultural properties for fire test. The size of full-scale model was 4.9 m length, 4 m wide, 6.6 m height, all was made by wooden. This real fire test results showed that the low pressure water mist nozzles having a $200{\mu}m$ dour size were very effectively fire extinguishing and suppression on wooden cultural properties fire. Even though the oil fuel fire was not extinguished, the fire suppression effects for the during mobilization of fire brigade was enough.

• Journal of Digital Convergence
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• v.16 no.10
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• pp.169-178
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• 2018

Gyeongin Port has low awareness, insufficient hinterland infrastructures, and lower competitiveness. So, in this study, we conducted Fuzzy-IPA analysis reflecting the recognition of the consignor companies that are using Gyeongin port to suggest present practical improvement measures for the activation of the operation of Gyeongin port hereafter. As a result of the analysis, three factors, that is, cargo loading/unloading/storage costs, port facility fees, and incentive and support were derived as priority investment areas. Three factors, that is, cargo safety, infrastructure equipment, and inland transportation costs were derived as the areas for maintenance strengthening and factors related to cargo handling and service factors were derived as areas for maintenance of the status quo and areas for gradual improvement, respectively. This study is significant in that it analyzed the recognition of the consignor companies that are using Gyeongin port using a quantifying method and suggested realizable measures for activation based on the results of the analysis. In future studies, the frequency of ships' calling at the port and measures to diversify the sea routes should be additionally reflected on the analysis.