• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.38-39
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• 2019

Environmental problems caused by GHG emitted by various industries are emerging around the world, and accordingly, relevant regulations are being applied by countries around the world. Korea is operating a carbon credit system that trades GHG in industry for money, which is expected to be applied to the construction industry. In addition, construction equipment using fossil fuels accounts for the largest portion of $CO_2$ emissions in the construction industry, and the importance of $CO_2$ reduction and prediction is increasing. However, there is a lack of data on the directly measured $CO_2$ emissions of construction equipment and there is no accurate methodology for measuring methods. Therefore, in this study, independent variables were derived based on the $CO_2$ emission data. In addition, multiple linear regression is performed for each independent variable to derive a predictive model of carbon dioxide emission by work type of construction equipment. It is expected that the construction process plan based on environmental factors in the construction industry can be established in the future.

• Korean Journal of Construction Engineering and Management
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• v.22 no.1
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• pp.106-115
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• 2021

Classifying work trades using images can serve an important role in a multitude of advanced applications in construction management and automated progress monitoring. However, images obtained from work sites may not always be clean. Defective images can damage an image classifier's accuracy which gives rise to a needs for a method to enhance a work trade image classifier's performance. We propose a method that uses work dependency information to aid image classifiers. We show that using work dependency can enhance the classifier's performance, especially when a base classifier is not so great in doing its job.

• Food Science and Industry
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• v.49 no.2
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• pp.51-55
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• 2016

The needs to develop high value-added foods are expanding due to the trends of food market, such as importance of food security by enlarged international free trades and expanded market size for processed foods. However, our home country exhibits limit transport to development of new products and high-value added area compared to other advanced countries. For this reason Ministry of Agriculture, Food and Rural Affairs and Institute of Planning and Evaluation for Technology have launched "High Value-Added Food Technology Development Program" for improvement of value of food resources for practical use since 2013. The program contains research to increase the values of agricultural and animal resources and the construction of database. Main research topics are studies in pretreatment techniques to improve the values of agricultural and animal resources, improvement of acceptability, and processing qualities that would be engrafted on materializaton and commercialization technologies. In addition the construction of a consolidated database regarding the research achievements is included in the program. Currently, studies in processing qualities for about 30 food materials re under progress, being suitable for materialization, for examples drying, fermentation, grinding, heat-treatment, and so on. The research results are provided in public through the consolidated database website after reconstruction in the form of united database format. To date the database containing the about 300 of research contents for process qualities has been constructed.

• Asia-Pacific Journal of Business
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• v.13 no.3
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• pp.463-473
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• 2022

Purpose - The purpose of this study is to examine the effect of the North Korea's net export to China and Liaoning on the North Korean economic growth. Design/methodology/approach - This study collects the data on the net export of North Korea to China and Liaoing from General Administration of Customs, People's Republic of China. Vector Autoregression(VAR) is also employed for the analysis. Findings - First, North Korea's net export to all of China and Liaoning gives the positive effect on North Korean economic growth. Second, the nuclear test of North Korea gives the negative effect on the North Korean economic growth. Third, the net export to China and Liaoning granger causes the North Korean economic growth. Lastly, the nuclear test of North Korea also granger causes the North Korean economic growth. Research implications or Originality - The estimation results show the net export of North Korea to China as well as Liaoning is important to the economic growth. Therefore, we need to examine North Korea's trades with specific region as well as all of China in order to enhance the North Korean economic growth.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.30 no.3
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• pp.86-91
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• 2022

This study empirically analyzes the patterns of import and export of air cargo between Korea and EU member states. In order to understand the detailed characteristics of the air transport sector, the amount of trade was analyzed by dividing it into exports, imports, and trades. As a result of the analysis, in terms of exports, imports, and trade, both EU member states' GDP per capita and Korea's GDP showed positive directions, while EU member states' GDP and Korea's per capita GDP both showed negative directions. In addition, international oil prices and exchange rates, which were expected to have an effect on aviation trade, did not show significant results in this study. On the other hand, when applying the fixed-effect model, both the country area and the number of airports excluded from the analysis were analyzed as positive directions as a result of the Houseman Taylor analysis.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.747-753
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• 2009

Planning the construction for a system of bored piles in building foundation engineering is (1) to predict the time duration required to complete all the bored piles with due consideration of relevant engineering factors and site constraints; then (2) to predict the total project time generally by aggregating the predicted working duration for construction of each bored pile. The duration for construction of an individual bored pile results from analyzing various working sequences and different activity duration (such as predrilling, excavation, steelfixing, air-lifting, and concreting, etc.), which is informed by experiences and site records of previous projects. However, determining the project duration for constructing many bored piles on one site is much more complicated than adding up the time duration for individual piles. In practice, project schedules are often found to be unrealistic and incorrect during the construction stage. This is because construction planning is not based on a exhaustive and comprehensive evaluation of site factors, such as site layout plan, site constraints, quality control, environmental control, safety control and logical relationships between different trades. In this paper, we identify those factors based on a foundation engineering site in Hong Kong with ninety-seven bored piles and address their effects on uncertainties in activity time and project time.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.632-639
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• 2022

The objective of this study is to analyze the productivity, efficiency, and factors affecting the productivity of a spray task from an international airport project. The study is focused on the productivity analysis of the Subcontractor whose job was to supply and apply sprayed-applied fire-resistive material (SFRM) on steel members to achieve the necessary fire ratings on the building structures of the Hamad International Airport, Qatar. The study analyzed the productivity of the four sprayer teams who completed the task at three locations and three areas of the airport. The study found that the productivity of the individual team observed during the SFRM spray task was not only different but was also observed different when they worked at varying floor heights where different factors affecting productivity were predominant. The study found that the efficiency was lowest (47.32%) when the spray team had to work at second-floor heights and factors affecting productivity such as limited accessibility for material movement and lifting, site congestion, lack of continuity of operation due to priority areas and frequent re-handling of machines and tools were present. Besides, the factors such as adverse weather conditions and sub-trades interference affected productivity at all locations. The findings show that productivity depends on multiple factors and those factors need to be identified and addressed to improve productivity. The findings also show that the estimated efficiency was hard to achieve but possible since Team 4 had 97% efficiency on the first floor of the airport.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.392-395
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• 2015

This study analyzes critical factors that affect issues of resolving time in BIM-based coordination using a case study. According to recent buildings that are meant to be more complex, BIM-based design coordination is regarded as an essential stage of the project delivery process. In the design coordination phase, a relocation of architectural, structural, mechanical, and electrical elements is conducted to avoid interference. In addition, the procedure of the development of each element in detail for the actual construction is carried out. Delays in coordination can affect delays in the entire delivery schedule of the project, and therefore many researches have focused on efficient coordination methods and how to shorten the period. In this study, we conducted a detailed analysis of the issue-resolving process using a case study, and found out that the participation of decision-makers for issue-resolving and the physical combination of trades affect delays in coordination time. In particular, we proposed the concept of organizational relation, indicating the level of decision-makers for issue-resolving, and the concept of physical relation, indicating the physical complexity of the issue, and we analyzed the effects of coordination delays.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.4
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• pp.93-100
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• 2023

In this paper, an alternative inventory policy that trades off the bullwhip effect at an upstream facility with cost minimization at a current facility, with the goal of reducing system wide total expected inventory costs, when external demand distributjon is autocorrelated, is considered. The alternative inventory policy has a form that is somewhere between one that completely neglects the autocorrleation and one that actively utilizes the autocorrelation. For this purpose, a mathematical model that allows us to evaluate system wide total expected inventory costs for a periodic review system is developed. This model enables us to identify an optimal inventory policy at a current facility that minimizes system wide total expected inventory costs by the best tradeoff of the bullwhip effect at an upstream facility with cost minimization at a current facility. From numerical experiments, it has been found that (i) when the autocorrelation is negative, the optimal policy is one that actively utilizes the autocorrelation, (ii) when the autocorrelation is small and positive, the optimal policy is one that neglects the autocorrelation, and (iii) when the autocorrelation is large and positive, the optimal policy is somewhere between one that actively utilizes the autocorrelation and one that neglect the autocorrelation.

• Korea Trade Review
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• v.46 no.1
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• pp.23-38
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• 2021

This paper investigated the preference change of payment terms in international trade along with counteroffer or first offer conditions of the other parties. Studies on trade payment terms have mainly focused on payment term determination factors such as firm size, product price level, country credit rate, etc. We tried to find other factors affecting payment terms choice, during the negotiation process. We applied behavioral economics theories such as 'Status Quo Bias' and 'Anchoring effect' to build our research model. To prove the existence of the above effects, we proceeded with field experiments to the exporting companies in Alibaba.com. Both 'Status Quo Bias' and 'Anchoring effect' were found in the field experiment. Most of the exporting companies preferred traditional payment methods to new payment methods. And an initial request for a low advance payment ratio led to a lower advance payment ratio. Also, the experience of using new payment methods could diminish status quo bias. This paper applied behavioral economics theories and field experiment methodology to the payment term studies in international trades. These attempts could contribute to expanding the diversity of methodology and scope of international trade studies.