• Journal of Korean Society for Atmospheric Environment
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• 제34권2호
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• pp.294-305
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• 2018

Quantitative assessment on the impact from North Korean emissions to surface particulate matter(PM) concentration in the Seoul Metropolitan Area (SMA), South Korea is conducted using a 3-dimensional chemistry transport model. Transboundary transport of air pollutants and their precursors are important to understand regional air quality in East Asian countries. As North Korea locates in the middle of main transport pathways of Chinese pollutants, quantifiable estimation of its impact is essential for policy making in South Korean air quality management. In this study, the Community Multiscale Air Quality Modeling System is utilized to simulate regional air quality and its sensitivity, using the Comprehensive Regional Emissions inventory for Atmospheric Transport Experiment 2015 and the Clean Air Policy Support System 2013 emissions inventories for North and South Korea, respectively. Contributions were estimated by a brute force method, perturbing 50% of North and South Korean emissions. Simulations demonstrate that North Korean emissions contribute $3.89{\mu}g/m^3$ of annual surface PM concentrations in the SMA, which accounts 14.7% of the region's average. Impacts are dominant in nitrate and organic carbon (OC) concentrations, attributing almost 40% of SMA OC concentration during January and February. Clear seasonal variations are also found in North Korean emissions contribution to South Korea (and vice versa) due to seasonal characteristics of synoptic weather, especially by the change of seasonal flow patterns.

• Journal of Environmental Impact Assessment
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• 제22권6호
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• pp.667-676
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• 2013

This study analyzed the energy demand, greenhouse gas emission and greenhouse gas reduction potential of Electronic Electrical components company. The LEAP model targeting long term energy plan was used to establish the most efficient plan for the companies by examining the climate change policy of government and the countermeasures by companies. A scenario was created by having 11 greenhouse gases reduction plans to be introduced from 2011 as the basic plan. Regarding input data, energy consumption by business place and by use, number of employee from 2009 to 2012, land area and change in number of business places were utilized. The study result suggested that approximately 13,800 TJ of energy will be spent in 2020, which is more than 2 times of 2012 energy consumption. When the integrated scenario based on the reduction plan of companies would be enforced, approximately 3,000 TJ will be reduced in 2020. The emission of greenhouse gases until 2020 was forecasted as approximately 760,000 ton $CO_2eq$. When the integrated scenario would be enforced, the emission will be approximately 610,000 ton $CO_2eq$, which is decrease by approximately 150,000 ton $CO_2eq$. This study will help the efficient responding of eElectronic Electrical components company in preparing detail report on objective management system and enforcement plan. It will also contribute in their image as environment-friendly companies by properly responding to the regulation reinforcement of government and greenhouse gases emission target based on environment policy.

• Journal of Korean Society for Atmospheric Environment
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• 제34권4호
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• pp.517-533
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• 2018

We utilize the CAMx (Comprehensive Air Quality Model with eXtensions) system and the PSAT (Particulate Source Apportionment Technology) diagnostic tool to determine the $PM_{2.5}$ concentration and to perform its source apportionment in the southeastern region of South Korea. For a year-long simulation, eight local authorities in the region such as Pohang, Daegu, Gyeongju, Ulsan, Busan-Gimhae, Gosung-Changwon, Hadong, and all remaining areas in Gyeongsangnam-do, are selected as source areas based on the emission rates of $NO_x$, $SO_x$, VOC, and primary PM in CAPSS (Clean Air Policy Support System) 2013 emissions inventory. The CAMx-PSAT simulation shows that Pohang has the highest $PM_{2.5}$ self-contribution rate (25%), followed by Hadong (15%) and Busan-Gimhae (14%). With the exception of Pohang, which has intense fugitive dust emissions, other authorities are strongly affected by emissions from their neighboring areas. This may be measured as much as 1 to 2 times higher than that of the self-contribution rate. Based on these estimations, we conclude that the efficiency of emission reduction measures to mitigate $PM_{2.5}$ concentrations in the southeastern region of South Korea can be maximized when the efforts of local or regional emission controls are combined with those from neighboring regions. A comprehensive control policy planning based on the collaboration between neighboring jurisdictional boundaries is required.

• Journal of Climate Change Research
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• 제9권3호
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• pp.263-271
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• 2018

Considering the high needs of recipient countries and the regional biases of Korean Official Development Assistance (ODA) policy, increases in the total amount of ODA and allocation to the forest sector are needed for Central Asia. In Tajikistan, illegal harvesting and grazing cause a gradual decrease in forest area. The Tajikistan government conserves forests by requesting international cooperation and establishing a policy for sustainable management of forest resources and prevention of further damages. To suggest suitable strategies and plans, the current statuses of forests and forestry were investigated, and ODA projects that can illustrate successful Korean experiences of forestation were conceived based on various geographical features and local conditions of Tajikistan in this study. Forest resource creation type projects (fuelwood and Tugai forest restoration) could result in energy independence and enhancement of ecosystem service such as a climate regulation and an increase in biodiversity. Community development type projects (introduction of ecotourism, agroforestry, and planting of fruit trees) can contribute to job creation and encourage participation of local residents, thus improving their incomes. In addition, establishment of a project foundation, including education, training, and a national forest inventory, would help those projects be sustainable in the long-term.

• Journal of the Korea Society of Computer and Information
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• 제14권2호
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• pp.211-219
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• 2009

The logistic environment of Korean companies faces very challenging circumstances due to lack of resources and tough price competitions. It is obvious that such a load of logistic cost becomes an obstacle to national or business competition advantages in the era of unlimited market competition. Prior studies concerning these issues sought to express a large-scale distribution network in a unified numerical formula using defined symbols and could take systematic approaches to distribution network. But inventory policy and operation in material distribution system have been limited to conventional methodology. so they are exposed to many questions in practical applications. This study analyzed distribution system cost and developed a relevant model for operation policy of distribution system for the efficeient treating of stockout. allowing practical applications, so that it will contribute to saving operational cost related to material distribution system.

• Journal of People, Plants, and Environment
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• 제22권6호
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• pp.699-709
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• 2019

Various health and social issues related to the elderly are emerging in line with the rapid aging of the population. In particular, dementia currently has a prevalence of about 10 percent of the elderly population in South Korea, which increases financial and social burdens to not only individual patients but also their caring family. To assess the effects of participating in the forest therapy programs for dementia prevention, this study recruited participants aged 50 and above and tested their depression (Korean form of Geriatric Depression Scale; KGDS) and stress response (Modified form of Stress Response Inventory; SRI-MF), which are emotional aspects of dementia. As a result, KGDS showed a significant decrease of 3.2 points from 8.4 to 5.2 points, and SRI-MF showed a significant decrease of 7.2 points from 40 to 32.8 points, indicating a statistically significant improvement in both. In addition, participants with minor depression and high level of stress in the pretest showed statistically significant improvements in the SRI-MF for men, and the KGDS and SRI-MF for women. Furthermore, there were statistically significant improvements in KGDS for participants in their 60s and in SRI-MF for those in their 70s in terms of age, and in both KGDS and SRI-MF for participants with chronic diseases and in KGDS for participants without chronic diseases. This study confirmed the effects of forest therapy on the prevention of the emotional aspects of dementia and laid the groundwork for increasing the applicability of forest therapy by obtaining a place for dementia prevention as a field of forest therapy.

• Industrial Engineering and Management Systems
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• 제10권2호
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• pp.115-122
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• 2011

This research considers a system containing a manufacturing firm who generates waste material during manufacturing process, and a disposal firm who collects and disposes the waste material. Identification of the optimal number of pick ups and the amount of waste to be disposed at certain period of time in terms of cost minimization is studied. Two types of waste accumulation rates, constant and linearly increasing, are discussed and mathematical models are developed. It can be shown that the results for these two different types of waste accumulation differ in a wide range because of the difference in the way of how waste is accumulated, which disturbs the storage cost. An integrated model is also developed and discussed in which both the manufacturing firm and the disposal firm benefit from the coordination between the two parties. It is shown that the optimal policy adopted by the integrated approach can provide a strong and consistent cost-minimizing effect for both the manufacturing firm and the disposal firm over the existing approach. Finally, all the models are verified by a numerical example and the results are compared.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 대한산업공학회/한국경영과학회 1996년도 춘계공동학술대회논문집; 공군사관학교, 청주; 26-27 Apr. 1996
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• pp.477-480
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• 1996

The main objective of this research is to develop the optimal control method for a Distribution Center - multi Branch inventory distribution system. With the continuous review policy, the distribution center places an order for specific order quantity to an outside supplier, and the order quantity is replenished after a certain lead time. Also, each branch places an order for particular order quantity to the distribution center to satisfy the customer demands, and receives the replenishment after a lead time. When an out of stock condition occurs during an order cycle, a backorder is placed to the upper level to fill the unfilled demands. With these situation, variable demand and variable lead time are used for better industrial practice. Futher, actual lead times with a generic lead time distribution are used in developing the control model. Under the actual lead time model, the customer service measures actually attained for the distribution center and each branch are explained as the effective customer service measures. Thus, throughout the optimal control (using computer search procedures), we can set the desired service levels for the distribution center and each branch to produce the effective service level for each branch which is consistent with the goal level of service for each branch. At the same time, the entire distribution system keeps minimum inventories.

• Women's Health Nursing
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• 제26권3호
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• pp.222-230
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• 2020

Purpose: Midwives working in hospitals (MWH) have limited roles in managing and assisting births independently. To find ways to successfully integrate midwifery into care systems, exploring midwives' work-related perceptions might be the first step. The purpose of this study was to compare professionalism and job satisfaction between Korean midwives working in birthing centers (MWBC) and MWH. Methods: A descriptive comparative design was used, querying 19 MWBC and 53 MWH in Korea. Data were accrued from October to November 2017 using the Professionalism Inventory Scale and the Job Satisfaction Scale. Results: Age, marital status, monthly income, length of career as a midwife, and length of career in the current workplace were significantly different between MWBC and MWH. The level of professionalism in MWBC showed significant differences by position at the birthing center (t=16.19, p=.001). Professionalism and job satisfaction among MWH showed significant differences depending on perceived professional performance (F=9.95, p<.001 and F=11.04, p<.001, respectively). Levels of professionalism and job satisfaction were higher for MWBC than for MWH. Conclusion: Educational programs designed to enhance professionalism and expand the role of MWH are suggested. Also, policy changes that clearly define job roles and improvement of the legal system is required to enable MWH in Korea to effectively perform their midwifery work and be properly reimbursed.

• Journal of the Korean Operations Research and Management Science Society
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• 제18권3호
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• pp.151-157
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• 1993

In this paper, we investigate the effects of yield randomness for lot-sizing in a multi-stage production system. The practical importance of incorporating yield randomness into production models has been emphasized by many researchers. Yield randomness, especially in semiconductor manufacturing, poses a mojor challenge for production planning and control. The task becomes even more difficult if the demand for final product is uncertain. An attempt to meet the demand with a higher level of confidence forces one to release more input in the fabrication line. This leads to excessive work-in-process (WIP) inventories which cause jobs to spend unpredictably longer time waiting for the machines. The result is that it is more difficult to meet demand with exceptionally long cycle time and puts further pressure to increase the safety stocks. Due to this spiral effect, it is common to find that the capital tied in inventory is the msot significant factor undermining profitability. We propose a policy to determine the quantity to be processed at each stage of a multi-stage production system in which the yield at each stage may be random and may need rework.