• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.5
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• pp.47-62
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• 2020

Rice paddy accounts for approximately 52.5% of all farmlands in South Korea, and it is closely related to the water environment. Climate change is expected to affect not only agricultural productivity also the water and the nutrient circulation. Therefore this study was aimed to evaluate changes of nitrogen load from rice paddy considering climate change scenario uncertainty. APEX-Paddy model which reflect rice paddy environment by modifying APEX (Agricultural Policy and Environmental eXtender) model was used. Using the AIMS (APCC Integrated Modeling Solution) offered by the APEC Climate Center, bias correction was conducted for 9 GCMs using non-parametric quantile mapping. Bias corrected climate change scenarios were applied to the APEX-Paddy model. The changes and uncertainty in runoff and nitrogen load were evaluated using multi-model ensemble. Paddy runoff showed a change of 23.1% for RCP4.5 scenario and 45.5% for RCP8.5 scenario compared the 2085s (2071 to 2100) against the base period (1976 to 2005). The nitrogen load was found to be increased as 43.9% for RCP4.5 scenario and 76.0% for RCP8.5 scenario. The uncertainty analysis showed that the annual standard deviation of nitrogen loads increased in the future, and the maximum entropy indicated an increasing tendency. And Duncan's analysis showed significant differences among GCMs as the future progressed. The result of this study seems to be used as a basis for mid- and long-term policies for water resources and water system environment considering climate change.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.3
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• pp.94-106
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• 2008

As populations inhabiting in natural ecosystem are fragmented by artificial barriers and habitats are destructed by development, extinction possibility of species is getting higher. It is necessary to design and to manage conservation areas and corridors considering animals' movement and migration for sustainable species diversity in present circumstances. 'Least-cost modeling' is one commonly employed approach in which dispersal costs are assigned to distinct habitat types and the last-costly dispersal paths among habitat patches are calculated using a geographical information system (GIS). This study aims to design ecological corridor using least-cost path method and to apply it to a regional ecological network considering movability of medium-large size mammals. This study was carried out over the metropolitan area, which has been deforested by rapid urbanization. Nevertheless there is connected with Gangwon province, Baekdudaegan mountain range and DMZ, considered where many forest species can migrate to this region. This study employs such an approach to develop least-cost path models for medium-large size mammals, have inhabited for this entire region. Considering those species, two forest areas as a source of species supply and forest areas more than 1,000ha are selected as focal forest areas. Movement and migration paths from species supply sources to focal forest areas are calculated by applying landscape permeability theory using land cover map, road density map and land slope map. Results showed least-cost paths from species supply sources to focal forest areas on two species. Wildcat and roe deer are different in some least-cost paths caused by their landscape permeability but paths show generally same specifics. The result of considering regional distribution of expected movement and migration paths to regional ecological network, low altitude mountains of western metropolitan area are evaluated important area for species connectivity. In national or regional levels ecological connectivity is essential to promote species diversity and to preserve integrated ecosystem. This study concludes that developing least-cost models from similar empirical data could significantly improve the utility of these tools.

• Culinary science and hospitality research
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• v.18 no.4
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• pp.27-46
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• 2012

Organizational factors and personal traits are two elements of widely acknowledged relevance in employees' organizational outcomes in hotel industry. Personal traits especially need to be further examined as a consideration for employment. As one of the personal traits that provide capability to manage emotions, emotional intelligence is selected. The empirical objective of this study is to investigate the effects of emotional intelligence on job satisfaction and organizational commitment in a structural model. To conduct research questions, five star deluxe hotel employees in Korea are targeted to be surveyed. Descriptive statistics and multivariate analysis of variance, and structural equation modeling(SEM) are utilized employing SPSS and AMOS 4.0 to analyze the survey results. It was found that the components of perceiving emotions and understanding emotions predicted job satisfaction. Relatively perceiving emotions presented a higher impact on each dimension of job satisfaction. Satisfaction with co-workers and communication can also explain the level of hotel employees' organizational commitment. Broadly speaking, the results suggest that effective psychotherapeutic or reciprocative programs should be integrated into hotel training contents for emotional intelligence development.

• The KIPS Transactions:PartD
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• v.8D no.1
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• pp.32-43
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• 2001

Due to the limitation of data modeling power and the view update ambiguity, relational view is limitedly used for engineering applications. On the contrary, object-oriented database view would playa vital role in defining custom interface for engineering applications because the above two limitations of the relational view are overcome by the object-oriented view. Above all, engineering application data interface should fully support updates. More specifically, updates against the data interface needs to be unambiguously defined and its semantic behavior should be equal to base schema updates'. For this purpose, we define the notion of update semantic preserving which means that view updates displays the same semantics as base schema. Besides, in order to show the feasibility of this characteristics, specific and concrete algorithms for update preserving updates are presented for a CAD specialized object-oriented database view - MultiView. This paper finds that in order that virtual classes coudld form a schema with 'isa' relationships rather than just a group of classes, the update semantics on the virtual classes should be defined such that the implied meaning of 'isa' relationships between classes are not to be violated. Besides, as its sufficiency conditions, we derived the update semantics and schema constituable conditions of the virtual classes that make view schemas look like base schemas. To my best knowledge, this is the first research that presents the sufficiency conditions by which we could defined object-oriented views as integrated schemas rather than as separate classes.

• The Journal of Society for e-Business Studies
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• v.16 no.4
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• pp.125-137
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• 2011

Product reviews in online shopping sites can serve as a useful guideline to buying decisions of customers. However, due to the massive amount of such reviews, it is almost impossible for users to read all the product reviews. For this reason, e-commerce sites provide users with useful reviews or statistics of ratings on products that are manually chosen or calculated. Opinion mining or sentiment analysis is a study on automating above process that involves firstly analyzing users' reviews on a product to tell if a review contains positive or negative feedback, and secondly, providing a summarized report of users' opinions. Previous researches focus on either providing polarity of a user's opinion or summarizing user's opinion on a feature of a product that result in relatively low usage of information that a user review contains. Actual user reviews contains not only mere assessment of a product, but also dissatisfaction and flaws of a product that a user experiences. There are increasing needs for effective analysis on such criteria to help users on their decision-making process. This paper proposes a model that stores various types of user reviews in a data warehouse, and analyzes integrated reviews dynamically. Also, we analyze reviews of an online application shopping site with the proposed model.

• Journal of the Korean Geographical Society
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• v.39 no.6 s.105
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• pp.873-887
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• 2004

We examined research trends in geomorphology and hydrogeography in America based on papers presented at the annual meetings of the Association of American Geographers(AAG) and papers published in two AAG journals between 2002 and 2004. Among the 437 papers in geomorphology, $40\%$ of the papers concerned fluvial geomorphology, followed by environmental geomorphology and glacial and periglacial geomorphology concern. Among the 452 papers in hydrogeography, about $20\%$ of the papers focused on water, law and institutional aspects, followed by hydrogeomorphology and hydrologic modeling. Twenty one papers examining geomorphology and hydeogeography were published in two AAG journals, and fluvial geomorpholoy was the dominant theme. GIS was used for $29\%$ papers in geomorphology and $35\%$ of papers in hydrogeography($35\%$), suggesting that other methods, including geostatistics, field survey, and qualitative methods, are employed as well. This methodological diversification seems to be associated with solving such complex environmental problems as integrated watershed management and implies that geomorphologists and hydrogeographers are expanding their traditional territories and are making close connections with human-environment geographers and human geographers. Geomorphologists and hydrogeographers are likely to continue examining the causes of and solving environmental problems that humans are currently facing and might face in the future.

• Journal of the Korean Chemical Society
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• v.53 no.6
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• pp.653-662
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• 2009

Developing effective tools for predicting absorption, distribution, metabolism, excretion properties and toxicity (ADME/T) of new chemical entities in the early stage of drug design is one of the most important tasks in drug discovery and development today. As one of these attempts, support vector machines (SVM) has recently been exploited for the prediction of ADME/T related properties. However, two problems in SVM modeling, i.e. feature selection and parameters setting, are still far from solved. The two problems have been shown to be crucial to the efficiency and accuracy of SVM classification. In particular, the feature selection and optimal SVM parameters setting influence each other, which indicates that they should be dealt with simultaneously. In this account, we present an integrated practical solution, in which genetic-based algorithm (GA) is used for feature selection and grid search (GS) method for parameters optimization. hERG ion-channel inhibitor classification models of ADME/T related properties has been built for assessing and testing the proposed GA-GS-SVM. We generated 6 different models that are 3 different single models and 3 different ensemble models using training set - 1891 compounds and validated with external test set - 175 compounds. We compared single model with ensemble model to solve data imbalance problems. It was able to improve accuracy of prediction to use ensemble model.

• Wind and Structures
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• v.30 no.4
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• pp.433-450
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• 2020

The strong turbulence characteristic of typhoon not only will significantly change flow field characteristics surrounding the large-scale wind turbine and aerodynamic force distribution on surface, but also may cause morphological evolution of coast dune and thereby form sand storms. A 5MW horizontal-axis wind turbine in a wind power plant of southeastern coastal areas in China was chosen to investigate the distribution law of additional loads caused by wind-sand coupling movement of coast dune at landing of strong typhoons. Firstly, a mesoscale Weather Research and Forecasting (WRF) mode was introduced in for high spatial resolution simulation of typhoon "Megi". Wind speed profile on the boundary layer of typhoon was gained through fitting based on nonlinear least squares and then it was integrated into the user-defined function (UDF) as an entry condition of small-scaled CFD numerical simulation. On this basis, a synchronous iterative modeling of wind field and sand particle combination was carried out by using a continuous phase and discrete phase. Influencing laws of typhoon and normal wind on moving characteristics of sand particles, equivalent pressure distribution mode of structural surface and characteristics of lift resistance coefficient were compared. Results demonstrated that: Compared with normal wind, mesoscale typhoon intensifies the 3D aerodynamic distribution mode on structural surface of wind turbine significantly. Different from wind loads, sand loads mainly impact on 30° ranges at two sides of the lower windward region on the tower. The ratio between sand loads and wind load reaches 3.937% and the maximum sand pressure coefficient is 0.09. The coupling impact effect of strong typhoon and large sand particles is more significant, in which the resistance coefficient of tower is increased by 9.80% to the maximum extent. The maximum resistance coefficient in typhoon field is 13.79% higher than that in the normal wind field.

• Proceedings of the Korea Society for Simulation Conference
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• 1997.04a
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• pp.65-65
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• 1997

가입자가 B-ISDN(Broadband Integrated Services Digital Network) 서비스에 대한 shb은 수준의 품질 및 안정적인 서비스 제공을 요구함에 따라, 이러한 서비스를 제공하기 위한 ATM (Asynchronous Transfer Mode) 교환기에 대한 신뢰성 설계의 중요성은 증가하 고 있다. 교환기의 중요한 신뢰성 성능 척도 중의 하나인 연결 절단율 (Cutoff connection rate)은 총 연결시간 동안 절단된 연결수로 정의되며, 연결 절단은 호 설정 (Call setup) 단 계를 지나 서비스 중인 연결이 사용자의 요구가 아닌 시스템의 고장으로 종료될 때 발생한 다. 연결 절단율 추정 문제는 기존의 신뢰도 또는 가용도 예측을 위한 시뮬레이션과는 달리 시스템 구성 유니트들의 고장율, 수리율, 그리고 요구된 연결의 트래픽 특성 부분이 혼합된 문제이다. 따라서, B-ISDN 서비스의 중요한 특징인 다양한 트래픽 특성과 시스템의 구성 (Configuration)을 고려하여 연결 절단율을 해석적인 방법을 통하여 추정하는 데네는 어려 움이 있으며 시뮬레이션에 의한 방법이 적절하다. 본 고에서는 B-ISDN 서비스의 트래픽 특 성과 ATM 교환기의 시스템 구성 및 신뢰도 데이터로부터 시스템의 연결 절단율을 추정하 기 위한 시뮬레이터의 기능 및 구조, 시뮬레이션 수행 결과 등을 제시한다. 시뮬레이터는 AweSim 시뮬레이션과 CUser Written Code를 사용하여 개발하였다. 시뮬레이터의 구성 모듈은 크게 호 도착 모듈, 연결 제어 및 자원 할당 모듈, 유니트 고장 및 수리 모듈, 통계 량 수집 모듈 등으로 구성된다. 개발된 시뮬레이터는 B-ISDN 트래픽 파라메터와 연결 절단 율의 상호 관계 규명 및 시스템 설계 대안 (Design alternatives)에 대한 비교/평가에 활용 된다., 수중생물의 경우는 특히 수온, 수량 영양원등이다.(중략). 본 연구의 접근방법으로는 ASRS의 개념적인 Reference Model을 수립하고 이 Reference Model에 대한 Formal Model로 DEVS(Discrete Event System Specification)을 이용하여 시스템을 Modeling하였다. 이의 Computer Simulation을 위하여 DEVS형식론 환경에서의 Simulation Language인 DEVSim ++ⓒ를 이용하여 시스템을 구현하였다.. 실형 결과로는 먼저 선형 상미분방정식의 예로 mass-damper-spring system, 비선형 상미분방정식의 예로는 van der Pol 방정식, 연립 상미분방정식의 예로는 mixing tank problem 등을 보였으며, 그의 공학에서 일어나는 여러 가지 문제들도 다루었다.화물에 대한 방어력이 증가되어 나타난 결과로 여겨지며, 또한 혈청중의 ALT, ALP 및 LDH활성을 유의성있게 감소시키므로서 감잎 phenolic compounds가 에탄올에 의한 간세포 손상에 대한 해독 및 보호작용이 있는 것으로 사료된다.반적으로 홍삼 제조시 내공의 발생은 제조공정에서 나타나는 경우가 많으며, 내백의 경우는 홍삼으로 가공되면서 발생하는 경우가 있고, 인삼이 성장될 때 부분적인 영양상태의 불충분이나 기후 등에 따른 영향을 받을 수 있기 때문에 앞으로 이에 대한 많은 연구가 이루어져야할 것으로 판단된다.태에도 불구하고 [-wh]의미의 겹의문사는 병렬적 관계의 합성어가 아니라 내부구조를 지니지 않은 단순한 단어(minimal $X^{0}$ elements)로 가정한다. 즉, [+wh] 의미의 겹의문사는 동일한 구성요 소를 지닌 병렬적 합성어([$[W1]_{XO-}$ $[W1]_{XO}$ ]$_{XO}$

• Journal of Digital Convergence
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• v.15 no.4
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• pp.327-337
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• 2017

The purpose of this study is to identify the current state of paid care services and to identify the factors that affect the utilization of private nursing services. This study constructed and utilized the Korean Health Panel data (2011-2014) in the form of panel data, and selected 5,110 patients who had experience using one or more hospitalization services per year. STATA 12.0 SE was used for data processing and analysis of this study. Frequency analysis was performed to confirm basic characteristics of hospitalized patients. Cross-analysis and t-test were conducted to confirm the status of paid care services according to characteristics. Respectively. Finally, panel logistic regression was performed by applying a hierarchical method to stepwise modeling the three categories of Andersen's Behavioral Model to identify factors affecting the use of paid care services for inpatients. The results showed that the use of paid nursing services was higher in women, elderly, long - term hospitalized and disabled. On the other hand, significant household income variables in private employment did not show significant results. The results of this study are expected to be used as basic data for the selection of the nursing care integrated services under discussion. In addition, detailed discussions on the selection of subjects should be made in the future.