• 한국환경과학회지
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• 제3권1호
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• pp.17-29
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• 1994

An one dimensional atmosphere-vegetation interaction model is developed to discuss of the effect of vegetation on heat flux in mesoscale planetary boundary layer. The canopy model was a coupled system of three balance equations of energy, moisture at ground surface and energy state of canopy with three independent variables of $T_f$(foliage temperature), $T_g$(ground temperature) and $q_g$(ground specific humidity). The model was verified by comparative study with OSUID(Oregon State University One Dimensional Model) proved in HYPEX-MOBHLY experiment. As the result, both vegetation and soil characteristics can be emphasized as an important factor iii the analysis of heat flux in the boundary layer. From the numerical experiments, following heat flux characteristics are clearly founded simulation. The larger shielding factor(vegetation) increase of $T_f$ while decrease $T_g$. because vegetation cut solar radiation to ground. Vegetation, the increase of roughness and resistance, increase of sensible heat flux in foliage while decrease the latent heat flux in the foliage.

• 한국보건간호학회지
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• 제28권2호
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• pp.285-297
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• 2014

Purpose: The purpose of this study was to investigate the structural relationship among the life stress, depression, suicidal ideation of adolescent. Methods: Participants for this study included 285 students from five middle schools located in Seoul and Gyeongsangbukdo, Korea. The SPSS 18.0 program and AMOS 18.0 program were used for analysis of data. Results: The characteristics of this study were to analyze causal relationship with latent variables by considering measurement error and to grasp direct effect, indirect effect and total effect. Life stress and depression were found to be factors influencing suicidal ideation. Depression was a direct factor and life stress was a indirect factor. The effects of depression as a mediator between life stress and suicidal ideation were significant statistically. Conclusion: The findings of this study may provide useful assistance in development of effective nursing interventions for prevention and management of middle school students' suicidal ideation.

• 한국의류학회지
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• 제28권11호
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• pp.1482-1494
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• 2004

This study identified convergent validity and discriminant validity of measurement variables by factor analysis using Spss program and tested covariance measurement model including latent variables such as the website attributes (interactivity, search and visual information of website), shopping values(utilitarian and hedonic value) and attitude toward website by AMOS program. The data were collected from a sample of 271 internet shopper of university students(male: 82, female: 189). They visited the website for apparel shopping and, after searching a casual clothing which they wanted to buy, requested to answer the questionnaire. The results were as follows: Variables that reduce validity were deleted in the several steps of factor analysis and initial measurement model testing. Final measurement model was constructed by valid variables was accepted. This measurement model will be input for testing causal research model that can explain how attributes of the website influences on consumer attitude toward the website.

• The Journal of Asian Finance, Economics and Business
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• 제4권3호
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• pp.85-94
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• 2017

The paper examines critical factors affecting consumer behavioral intentions in accepting online health communication through social networking sites. Unlike recent research under this topic, the paper assimilates some components of service quality dimensions and consumer behavior theories. The paper employs factor analysis and structural equation modelling analysis with latent variables to identify critical factors from the survey data collected from Korean consumers. The results of the study identifies three major constructs: consumer needs for health information, the perceived value of tangible attributes of health information providers, and the perceived value of intangible attributes of health information providers. The results show that consumer needs for health information and the tangible and intangible attributes of health information providers should be considered as important antecedents of accepting online health communication through social networking sites. The findings suggest that the success of online health communication via social networking sites largely depends on the tangible and intangible attributes of health information providers.

• 사회복지연구
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• 제42권3호
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• pp.381-407
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• 2011

본 연구는 사회복지조직의 사회적 자본을 연구하는 연구자들이 활용할 수 있는 타당하고 신뢰도가 높은 사회적 자본 척도를 구성하여 적용해 봄으로써 사회복지조직 간 사회적 자본 수준의 차이가 나는지 살펴보는 연구이다. 이를 위해 전국 15개 시·도의 사회복지조직을 대상으로 우편 설문조사를 실시한 후, 잠재평균분석을 실시하였다. 본 연구의 주요 결과는 다음과 같다. 첫째, 탐색적 요인분석과 확인적 요인분석 결과, 본 연구에서 구성한 사회적 자본 척도는 타당하고 신뢰로운 것으로 나타났다. 둘째, 분석 수준에 대한 검토 결과, 사회적 자본 변수는 조직 수준에서 해석 가능함이 확인되었다. 셋째, 사회적 자본의 형태 동일성, 측정 동일성, 절편 동일성 확인결과, 본 연구에서 개발한 사회적 자본 척도는 사회복지조직에 공통적으로 적용 가능한 것으로 나타났다. 마지막으로, 잠재평균분석을 통하여 사회적 자본의 하위 지표인 네트워크 연결성, 비전 설정 및 공유, 호혜적 규범, 신뢰 및 협력, 단체참여에 대한 사회복지조직 간 차이를 살펴본 결과, 네트워크 연결성, 호혜적 규범, 신뢰 및 협력, 단체참여에 있어 조직 간 통계적으로 유의미한 차이가 발견되었으나, 비전 설정 및 공유에 있어서는 조직 간 통계적으로 유의미한 차이가 발견되지 않았다. 이상의 결과를 바탕으로 사회복지 조직관리에 필요한 시사점을 도출하였다.

• 인터넷정보학회논문지
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• 제15권6호
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• pp.77-84
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• 2014

본 연구는 대학에서 이러닝을 활용 수업의 효과에 영향을 미치는 요인들을 탐색하고 요인들 간의 인과관계를 파악하고자 하였다. 이를 위해 2013년 2학기를 기준으로 이러닝 기반의 수업인 사이버 강의에 참여한 학생들 2,091명 중 유효했던 1,732명을 연구 대상으로 하였다. 연구방법은 확인적 요인분석과 구조방정식모형 분석을 활용하였다. 확인적 요인분석을 통해 이러닝 학습효과, 컨텐츠만족요인, 시스템기능요인, 운영지원요인의 네 개의 잠재변인을 도출할 수 있었다. 이들 잠재변인들 간의 구조방정식 모델 분석을 통한 결과는 다음과 같다. 첫째, 이러닝 학습효과와 관련된 주요 요인으로 컨텐츠 요인, 기능요인, 운영지원 요인으로 구분할 수 있었다. 둘째, 이러닝 학습효과에는 운영지원, 컨텐츠 요인이 직접적 영향을 미치는 것으로 나타났다. 하지만 기능요인은 유의하지 않은 것으로 나타났다. 셋째, 컨텐츠 요인에는 기능 및 운영요인이 유의한 영향을 미치는 것으로 나타났다. 넷째, 기능요인 및 운영지원요인은 컨텐츠 요인을 매개로하여 이러닝 학습효과에 간접적 영향을 미치는 것으로 나타났다.

• 한국항해학회지
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• 제15권2호
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• pp.39-47
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• 1991

As per the rapid development of world economics the marine traffic volume was increased accordingly and caused frequent disasters in human lives and natural environment in the consequence of accidents. As the result of the above they started to establish Vessel Traffic System(VTS) and separation scheme in waterway from 1960' to prevent the marin traffic accident but the problem of safety at sea appears now as neither fully defined nor sufficiently analysed. At the present, the dominant factor in establishing the strategy of marine traffic has been safety of navigation concerning only with the ship, but the risk of society derives almost wholly from the nature of cargo. To measure the degree of danger for each ship there is suggested concept of safety factor numbers denoting the level of latent danger in connection with ship and her cargo. In this paper, where the strategy of VTS is put on controlling density of safety factor for control area. it suggested algorithms how to assign the vessels and also to get optimal sequence of vessels located to a sector in the sense of minimizing the passage delay. For the formulation of problem, min max and 0-1 programming methods are applied and developed heuristic algorithm is presented with numerical example to improve the efficiency of calculation.

• 설비공학논문집
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• 제17권11호
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• pp.1014-1021
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• 2005

Flow channels with non-circular cross-sections are encountered in a wide variety of heat exchangers. Accurate friction factor and Colburn j factor data are essential for the design and viable applications of such heat exchangers. In this study, an analysis is con ducted on heat transfer and pressure drop characteristics for tube-bundle heat exchanger with various arrangements of tubes, of which their geometry could easily be modified from a circular one in a harsh environment. The parameters investigated are aspect ratio, pitch, and inclined angle of tubes. The results obtained are: (1) Aspect ratio has larger influence on the j and f factor than pitch; (2) As aspect ratio increases, both j and f factors decrease; (3) The high performance is achieved when the pitch and aspect ratio are in the range of 1.5${\~}$2.5 and 1.25${\~}$2.0, respectively; and (4) the inclined arrangements of tubes show unfavorable results for both heat transfer and pressure drop characteristics in spite of the positive possibility of condensate removals in a latent heat recovery system.

• 무역상무연구
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• 제30권
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• pp.3-26
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• 2006

Supply chain is viewed as a number of organizations(at least three) working cooperatively with at least some shared objectives. The concept of supply chain management represents the most advanced state in the evolutionary development of purchasing, procurement and other supply chain activities. This study aims to analyze and develop a measurement instrument for supply chain performance in international logistics. A measurement instrument for supply chain performance in international logistics are developed by Lai et al(2002). Supply chain reliability, customer service and cost are constructed reflecting service effectiveness and operations efficiency between shipper, forwarder and liner. The results of this study are as follow. We firstly tested the measurement properties of the sub-dimension of the supply chain performance construct using reliability test and confirmatory factor analysis follow by exploratory factor analysis. For each of the factor, reliability and validity are achieved because of the significant loading of the measurement items on their latent factors. Further research perform the analysis of variance by multi respondents within each firm and across partner firms in the supply chain. The result of analysis present the difference with shipper, forwarder and liner in statistics.

• 설비공학논문집
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• 제11권4호
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• pp.549-559
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• 1999

An experimental study was peformed to measure the viscosity of microencapsulated PCM slurries as the functions of its concentration and temperature, and also influence to its fluid dynamics. For the viscosity measurement, a rotary type viscometer, which was equipped with temperature control system, was adopted. The slurry was mixed with water and Sodium Lauryl Sulphate as a surfactant by which its suspended particles were dispersed well without the segregation of particles during the experiment. The viscosity was increased as the concentration of MicroPCM particle added. The surfactant increased 5% of the viscosity over the working fluid without particles. Experiments were proceeded by changing parameters such as PCM particles'concentration as well as the temperature of working fluid. As a result, a model to the functions of temperature for the working fluid and its particle concentration is proposed. The proposed model, for which its standard deviation shows 0.8068, is agreed well with the reference's data. The pressure drop was measured by U-tube manometer, and then the friction factor was obtained. It was noted that the pressure drop was not influenced by the state of PCM phase, that is solid or liquid in its core materials at their same concentration. On the other hand, it was described that the pressure drop of the slurry was much increased over the working fluid without particles. A friction factor was placed on a straight line in all working fluids of the laminar flow regardless of existing particles as we expected.