• Journal of Korea Water Resources Association
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• v.52 no.10
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• pp.707-718
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• 2019

The optimal water allocation pursues a reliable and economic supply of water resources to meet various interests in socio-economic-environmental aspects. The global water shortage has intensified due to climate change and population growth with limited water resources. Thus, the water management scheme has shifted to improve water use efficiency by proper demand management and water allocation planning. Here, a hydro-economic water allocation model, called WAMM (Water Allocation and Management Model) is introduced. The WAMM is equipped with an improved linear programming algorithm for optimal water allocation and estimates economic value of water supply as an objective of water

• Korea Trade Review
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• v.43 no.2
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• pp.47-67
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• 2018

The purpose of this study is to determine factors of FDI inflows which positively influence economic development. While MNCs ultimately decide on which country to engage in FDI, it can be affected by the general investment environment of host countries. Thus, it may be closely linked to national macro socio-economic factors. In the fixed-effect panel regression analysis using 30 years of data of 13 developed countries and 15 developing countries, results indicate that labor redemption exerts the greatest influence on global FDI inflows; this implies that FDI decisions are based on locations featuring higher productivity by the reduction of labor costs. According to the level of economic development, the motive of FDI inflows differs. In developed countries, GDP, government expenditure and consumer expenditure exert the greatest influence on FDI inflows; which shows characteristics of market seeking and horizontal investment. However, in developing countries, labor redemption and human capital exert the greatest influence on FDI inflows; which shows characteristics of efficiency seeking and vertical investment.

• Journal of the Korean Geographical Society
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• v.49 no.3
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• pp.423-437
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• 2014

Districting is a spatial decision making process to make a new regional framework for affecting human activities. Natural barriers such as rivers and mountains located within a reorganized district may reduce the efficiency of reorganized human activities. This implies that it is necessary to consider boundary characteristics in a districting process. The purpose of this research is to develop a new spatial optimization model based on boundary characteristics for districting problems. The boundary characteristics are evaluated as continuous value expressing the possibility of combining adjacent two basic spatial units rather than a dichotomous value with 1 or 0 and are defined as an objective function in the model. In addition, the model has explicitly formulated contiguity constraints as well as constraints enforcing demand balance among districts such as population and area. The boundary attributes are categorized into physical and relational characteristics. Suitability analysis is used to combine various variables related to each boundary characteristic and to evaluate the coupling possibility between two neighboring basic units. The model is applied to an administrative redistricting problem. The analytical results demonstrate that various boundary characteristics could be modeled in terms of mixed integer programming (MIP).

• The Journal of the Korea Contents Association
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• v.15 no.12
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• pp.560-571
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• 2015

This study aims to examine primary determinant for medical expenditure depending on different age and income brackets. The age and income brackets are simultaneously taken into account for a forming of structural models, and GARCH methodology is utilized in analyzing the model. Empirical evidence reveals that no matter how general medical care system is appropriately operated, medical expenditure is vulnerable in taking care of potential socially-disadvantaged class and the group of catastrophic medical expenditure as long as the age and income brackets concern, simultaneously. It signifies that more elaborately designed medical-related policy seems to be established to improve its effectiveness. On the contrary, ageing society is comparatively well-treated by public health law and act on long-term care insurance for the aged.

• Journal of Platform Technology
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• v.11 no.3
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• pp.45-55
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• 2023

This paper presents a model that supports decision-makers in the Korean film industry to maximize the success of online movies. To achieve this, we collected historical box office movies and clustered them into types to propose a model predicting each type's online box office performance. We considered various features to identify factors contributing to movie success and reduced feature dimensionality for computational efficiency. We systematically classified the movies into types and predicted each type's online box office performance while analyzing the contributing factors. We used automated machine learning (AutoML) techniques to automatically propose and select machine learning algorithms optimized for the problem, allowing for easy experimentation and selection of multiple algorithms. This approach is expected to provide a foundation for informed decision-making and contribute to better performance in the film industry.

• Journal of Hospice and Palliative Care
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• v.15 no.1
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• pp.18-29
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• 2012

Purpose: We analyzed how clinical nurses in Korea perceive terminally ill patients' medical decision-making. Methods: The Q-methodology which analyzes the subjectivity of each item was used. We selected 34 Q-statements among those provided by each of 37 subjects and grouped them into a shape of normal distribution using a 9 point scale. The collected data were analyzed using a QUANL PC program. Results: Four types of perception toward medical decision-making were identified. Type I focuses on patient participation, and Type II emphasizes the role of health professionals. Type III is characterized by an open-minded culture toward death, and Type IV values the role of family members. Conclusion: The results of this study indicate the need for development of a multi-disciplinary curriculum medical decision-making and death for medical and nursing students.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.599-604
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• 2005

최근 일부 댐유역에서 게릴라성 집중호우와 태풍 등과 같은 특이 호우에 대하여 강우-유출분석을 실시한 결과 유출율이 $100\%$를 상회하는 경우가 발생함에 따라 효율적이고 안전한 치수 및 방재업무를 실시하는데 많은 어려움을 겪고 있다. 본 연구에서 일부 댐유역의 유출율이 $100\%$를 상회하는 원인으로 강우 관측자료의 신뢰성이 결여되어 나타나는 것으로 보았으며, 만일, 강우관측소에서 계측된 강우자료의 신뢰성이 결여 되어 있다면, 이로 인한 유역 강우의 추정오차는 제거될 수 없을 것이다. 일반적으로 강우관측소에서 발생하는 계측오차는 관측소의 고도, 지형적인 장애(산악영향, 지장물 등) 및 기상학적인 장애(기단의 이동방향, 호우의 발생원인, 돌풍 등) 등 외부적인 요인으로 인해 발생할 수 있다. 따라서, 본 연구에서는 강우관측소에서 발생하는 계측오차의 다른 여러 외부적 요인들 중 가장 큰 요인으로 돌풍과 같은 풍속에 의해 발생하는 것으로 판단하였고, 연구대상 유역인 임하댐 유역의 유출율과 치대 풍속간의 상관분석을 실시하였으며 분석결과 유출율은 최대 풍속에 커다란 영향을 받는 것으로 나타났다. 결국, 유출율이 $100\%$를 상회하는 호우에서 강우관측소의 강우는 강우시 돌풍과 같은 외부적인 요인으로 인해 적게 관측된 것으로 추정되며 저평가된 강우자료로부터 산정된 면적평균강우의 추정오차로 인해 유출율이 $100\%$를 상회하는 것으로 나타났다. 따라서 본 연구에서는 유출율과 풍속간의 관계로부터 강우보정계수 추정식을 산정하였으며, 추정된 보정계수를 이용하여 관측된 강우자료를 보정한 후 강우-유출분석을 실시한 결과 댐유입수문곡선을 보정전에 비해 보다 근사하게 모의하였다. 위해서는 대상유역에 적합한 선행 강우일수의 결정이 중요하리라 판단된다.인 분석을 수행하고, 배수갑문 개방에 의한 수질개선효과를 최대화하기 위한 환경관리 방안 제시에 중점을 두어 수행하였다.ncy), 환경성(environmental feasibility) 등을 정성적으로(qualitatively) 파악하여 실현가능한 대안을 선정하였다. 이렇게 선정된 대안들은 중유역별로 검토하여 효과가 있을 것으로 판단되는 대안들을 제시하는 예비타당성(Prefeasibility) 계획을 수립하였다. 이렇게 제시된 계획은 향후 과학적인 분석(세부평가방법)을 통해 대안을 평가하고 구체적인 타당성(feasibility) 계획을 수립하는데 토대가 될 것이다.{0.11R(mm)}(r^2=0.69)$로 나타났다. 이는 토양의 투수특성에 따라 강우량 증가에 비례하여 점증하는 침투수와 구분되는 현상이었다. 경사와 토양이 같은 조건에서 나지의 경우 역시 $Ro_{B10}(mm)=20.3e^{0.08R(mm)(r^2=0.84)$로 지수적으로 증가하는 경향을 나타내었다. 유거수량은 토성별로 양토를 1.0으로 기준할 때 사양토가 0.86으로 가장 작았고, 식양토 1.09, 식토 1.15로 평가되어 침투수에 비해 토성별 차이가 크게 나타났다. 이는 토성이 세립질일 수록 유거수의 저항이 작기 때문으로 생각된다. 경사에 따라서는 경사도가 증가할수록 증가하였으며 $10\% 경사일 때를 기준으로 $Ro(mm)=Ro_{10}{\times}0.797{\times}e^{-0.021s(\%)}$로 나타났다.천성 승모판 폐쇄 부전등을 초래하는 심각한 선천성 심질환이다. 그러나 진단 즉시 직접 좌관상동맥-대동맥 이식술로 수술적 교정을 해줌으로

• Journal of Distribution Science
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• v.5 no.1
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• pp.57-73
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• 2007

There are more problems in distributing agricultural and special products than industrial products because they have such restrictions as seasonal fluctuation in the quantity, indeterminate and diverse shapes, many farm households, a small amount of shipment, and mandatory guide and maintenance. However, with social atmosphere called well-being, there are increasing concerns about inorganic agricultural products and direct trade with farmers. It is therefore urgent to stabilize the price of agricultural and special products and to correctly grasp and improve logistics activities for those dealing with agricultural and special products in order to supply fresh ones. This study aimed at examining logistics activities and the information technology level for agricultural and special products, determining how these factors affect logistics performance, and eventually suggesting a scheme to improve the logistics achievements for agricultural and special products. For this purpose, it selected information technology and logistics activity levels as independent variables and logistics performance as a dependent variable. The information technology level was measured for utility, holding level, and concern, respectively, and the logistics activity level was tested for the level of using the logistics information system in those companies concerned. From the above-mentioned findings, it is urgent to enhance distribution technology and its level immediately since distribution of agricultural and special products is poor in Korea and good distribution can contribute to a reduction of logistics costs or improvement of customer service.

• The Journal of Society for e-Business Studies
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• v.24 no.3
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• pp.19-33
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• 2019

Recently, manufacturers have been struggling to efficiently use production equipment as their production methods become more sophisticated and complex. Typical factors hindering the efficiency of the manufacturing process include setup cost due to job change. Especially, in the process of using expensive production equipment such as semiconductor / LCD process, efficient use of equipment is very important. Balancing the tradeoff between meeting the deadline and minimizing setup cost incurred by changes of work type is crucial planning task. In this study, we developed a scheduling model to achieve the goal of minimizing the duedate and setup costs by using reinforcement learning in parallel machines with duedate and work preparation costs. The proposed model is a Deep Q-Network (DQN) scheduling model and is a reinforcement learning-based model. To validate the effectiveness of our proposed model, we compared it against the heuristic model and DNN(deep neural network) based model. It was confirmed that our proposed DQN method causes less due date violation and setup costs than the benchmark methods.

• Journal of the Earthquake Engineering Society of Korea
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• v.9 no.5 s.45
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• pp.41-52
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• 2005

Using the variable control gain scheme on the basis of fuzzy-based decision-making process, Fuzzy supervisory control (FSC) technique exhibits better control performance than linear control technique with one static control gain. This paper demonstrates the effectiveness of the FSC technique by evaluating the robust performance of the FSC technique under the presence of uncertainties in the models and the excitations. Robust performance of the FSC system is compared with that of optimally designed LQG control system for the benchmark cable-stayed bridge presented by Dyke et al. Parameter studies on the robust performance evaluation are carried out by varying the stiffness of the bridge model as well as the magnitudes of several earthquakes with different frequency contents. From the comparative study of two control systems, FSC system shows the enhanced control performance against various magnitudes of several earthquakes while maintaining lower level of power required for controlling the bridge response. Especially, FSC system clearly guarantees the improved robust performance of the control system with stable reduction effects on the seismic responses and slight increases in total power and stroke for the control system, while LQG control system exhibits poor robust performance.