• Nuclear Engineering and Technology
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• v.23 no.1
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• pp.56-65
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• 1991

The LOFT LOCE L2-3 was simulated using the RELAP5/MOD2 Cycle 36.04 code to assess its capability in predicting the thermal-hydraulic phenomena in LBLOCA of a PWR. The reactor vessel was simulated with two core channels and split downcomer modeling for a base case calculation using the frozen code. The result of the base calculation showed that the code predicted the hydraulic behavior, and the blowdown thermal response at high power region of the core reasonably and that the code had deficiencies in the critical How model during subcooled-two-phase transition period, in the CHF correlation at high mass flux and in the blowdown rewet criteria. An overprediction of coolant inventory due to the deficiencies yielded the poor prediction of reflood thermal response. Improvement of the code, RELAP5 / MOD2 Cycle 36.04, based on the sensitivity study increased the accuracy of the prediction of the rewet phenomena.

• Journal of the Korean Wood Science and Technology
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• v.44 no.3
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• pp.449-456
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• 2016

This study was aimed to quantify the amount of carbon dioxide emissions and to suggest suitable plans which consider the carbon emission reduction in the manufacturing process of the domestic structural glued laminated timber. Field investigation on two glued laminated timber manufacturers was conducted to find out material flow input values such as raw materials, transportation, manufacturing process, and energy consumption during manufacturing process. Based on the collected data and the relevant literatures about life cycle inventory (LCI), the amount of carbon dioxide emission per unit volume was quantified. Results show that the carbon dioxide emissions for sawing, drying and laminating process are 31.0, 109.0, 94.2 kg $CO_2eq./m^3$, respectively. These results show 13% lesser amount of total carbon dioxide emissions compared with the imported glued laminated timber in Korea. Furthermore, it was decreased about 37% when the fossil fuel would be replaced with biomass fuel in drying process. Findings from this study is effectively used as the basic data on the life cycle assessment of wooden building.

• Clean Technology
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• v.28 no.1
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• pp.9-17
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• 2022

Electrochemical carbon dioxide (CO₂) reduction technology, one of the promising solutions for climate change, can convert CO₂, a representative greenhouse gas (GHG), into valuable base chemicals using electric energy. In particular, carbon monoxide (CO), among various candidate products, is attracting much attention from both academia and industry because of its high Faraday efficiency, promising economic feasibility, and relatively large market size. Although numerous previous studies have recently analyzed the GHG reduction potential of this technology, the assumptions made and inventory data used are neither consistent nor transparent. In this study, a comparative life cycle assessment was carried out to analyze the potential for reducing GHG emissions in the electrochemical CO production process in a more transparent way. By defining three different system boundaries, the global warming impact was compared with that of a fossil fuel-based CO production process. The results confirmed that the emission factor of electric energy supplied to CO₂-electrolyzers should be much lower than that of the current national power generation sector in order to mitigate GHG emissions by replacing conventional CO production with electrochemical CO production. Also, it is important to disclose transparently inventory data of the conventional CO production process for a more reliable analysis of GHG reduction potential.

• International Journal of Quality Innovation
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• v.4 no.1
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• pp.160-174
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• 2003

This study researched an enterprise resources planning (ERP) implementation project at a printed circuit board (PCB) manufacturer. In depth research was achieved by participating and observing in an implementation project at an actual PCB manufacturer. It is hoped that this study will contribute a valuable reference resource for future PCB manufacturers that wish to select or implement ERP systems. The first step in implementing ERP software is to set a clear target. At the same time, the tasks of each department and the system of cooperation between departments must be clearly defined. In this way, the cycle time of each flow and the accuracy of data will both be improved. In order to ensure smooth implementation of an ERP project, the followings are key factors: (1) an ERP system that suits the PCB industry; (2) effective project management; (3) effective project cost/budget control; (4) project problem management system; (5) comprehensive implementation method and information technology (IT), etc. By keeping to these principals, Company A achieved rapid transactions, and lower total cycle times and inventory levels, and other such benefits that had been predicted.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1244-1249
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• 2007

Pursuing sustainable development throughout society and industry and the field of environmental policy, each international organization or nation has performed international standardization projects on environmental management activities for their system as well as environmental assessment for a product such as life cycle assessment (LCA) and life cycle inventory database (LCI DB), and the environmental aspects have been increasingly demanded as crucial evaluation specifications. Moreover, the conventional environmental policy, which represents the direct-control, has been more dependent on the market forces and product itself after the Climate Change Convention., and the Integrated Product Policy (IPP, EU) is applied vigorously to strengthen global competitiveness of a product and to achieve the effect of environmental improvement for it. According to change of the international railway market, the value of Eco-Design has been increasingly important in developed countries including EU. Thus, each country is establishing its own guidelines, software and database for each product, and developing new policies through Eco-Design with practical results in marketing. To react this and develop Korean railway as an environment-friendly industry with priority to other transportation system as well as maintain high place in technology, the direction of RACE software development of main function is introduced, which is exclusively used for EMU to assess both environmental and economic aspects with LCA and eco-efficiency (EE).

• Clean Technology
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• v.14 no.2
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• pp.144-151
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• 2008

Life cycle assessment was carried out to evaluate the environmental values of dimethylas a diesel alternative fuel with the assumption of dimethyl ether production from natural gas via synthesis gas. The whole life cycles from raw material acquisitions to the final usages of diesel and dimethyl ether were involved in the assessment. Inventory analysis showed that the most significant environmental impacts came from resource depletions and air emissions. Impact assessment revealed that dimethyl ether was environmentally better in the aspect of human health and ecosystem quality but worse in resource depletions compared with diesel fuel. Suggestions for environmental improvement of dimethyl ether as a diesel alternative fuel were prepared based on the assessment results.

• Journal of the Korean Operations Research and Management Science Society
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• v.36 no.3
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• pp.91-105
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• 2011

In this paper, we analyze a logistic system involving a supplier who produces and delivers multiple types of items and a buyer who receives and sells the products to end customers. The buyer controls the inventory level by replenishing each product item up to a given order-up-to-level to cope with stochastic demand of end customers. In response to the buyer's order, the supplier produces or outsources the ordered item and delivers them at the start of each period. For the system described above, a mathematical model for a single type of item was developed from the buyer's perspective. Based on the model, an efficient method to find the cycle length and safety factor which correspond to a local minimum solution is proposed. This single product model was extended to cover a multiple item situation. From the model, algorithms to decide the base cycle length and order interval of each item were proposed. The results of the computational experiment show that the algorithms were able to determine the global optimum solution for all tested cases within a reasonable amount of time.

• Journal of Energy Engineering
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• v.8 no.4
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• pp.612-620
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• 1999

Environmental impact assessment in the step of the Life Cycle Assessment (LCA) measures relative values of importance or weight of the environmental load characterized in the inventory analysis. The weight measurements are used to evaluate the environmental load or the effect of the industrial product or technology. In this paper the Analytic Network Prpcess (ANP) is introduced to calculate a relative weighting of the environmental impact. The ANP is considered as one of the useful decision making framework and allow for more complex interrelationships, feedback, and inner/outer dependence among the decision level and factors. The weighting from the ANP may applied to obtain the overall evaluation value of environmental load.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.3
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• pp.229-235
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• 2021

The ability of entrepreneurs to arrange working capital is the key to maximizing the profitability of small- and medium-sized enterprises and the wealth of entrepreneurs. The study investigates the correlation between entrepreneurs' working capital management and the profitability of SMEs listed on six Gulf Cooperation Council (GCC) stock exchanges between 2019 and 2020. The secondary data is collected from the financial statements of SMEs listed on the six GCC stock exchanges. Actual sample for the research study was a total of 136 small- and medium-sized enterprises selected using purposive sampling methods. Four research models were considered in this analysis, all ending up affecting gross profits. The selected entrepreneurial SMEs were listed on six different Gulf Cooperation Council stock exchanges during 2019-2020. The fixed financial assets ratio, financial debt ratio, and company size are used as control variables and data were analyzed using multiple regression. The research results demonstrate that there is a statistically significant negative correlation between profitability measured by gross profit and cash cycle and the components of the cash cycle (including days of accounts receivable and days of inventory). The study further reveals that there is no significant correlation between gross profit and days of accounts payable.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1625-1629
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• 2009

The new paradigm called 'Low Carbon Green Growth' involved in reducing greenhouse gas is on the rise as a critical issue worldwide. The essential of Kyoto protocol issued in 1997 is to achieve the sustainable economic growth environments by converting existing production system to eco-friendly one. The protocol imposes the liability to reduce greenhouse gas to the countries joined to it. The paradigm is directly involved in the energy consumption and environmental pollution caused by construction activities. Value Engineering which are mainly applied in the design phase in practice is a measure to improve the value of a constructed facility by analyzing and/or appraising the functions and costs of it. However, an appropriate method which assesses eco-friendliness of constructed facility has not been propose by researchers. This paper proposes a method which assesses the performance involved in eco-friendliness of constructed facility using Value Engineering (VE) in the design phase. The method estimates the environmental cost relative to the amounts of energy consumption and environmental pollution occurred over the entire project life cycle. The database called "Life Cycle Inventory DB", which stores information about the amounts of environmental pollution, is used. The algorithm which retrieves the amounts of environmental pollutions from the DB and converts them into environmental costs is developed. The algorithm is implemented into a system which quantifies the eco-friendliness of constructed facility in the design phase using VE.