• Title/Summary/Keyword: Theoretical models

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Sensitivity of COMS/GOCI Measured Top-of-atmosphere Reflectances to Atmospheric Aerosol Properties (COMS/GOCI 관측값의 대기 에어러솔의 특성에 대한 민감도 분석)

  • Lee, Kwon-Ho;Kim, Young-Joon
    • Korean Journal of Remote Sensing
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    • v.24 no.6
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    • pp.559-569
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    • 2008
  • The Geostationary Ocean Color Imager (GOCI) on board the Communication Ocean Meteorological Satellite (COMS), the first geostationary ocean color sensor, requires accurate atmospheric correction since its eight bands are also affected by atmospheric constituents such as gases, molecules and atmospheric aerosols. Unlike gases and molecules in the atmosphere, aerosols can interact with sunlight by complex scattering and absorption properties. For the purpose of qualified ocean remote sensing, understanding of aerosol-radiation interactions is needed. In this study, we show micro-physical and optical properties of aerosols using the Optical Property of Aerosol and Cloud (OPAC) aerosol models. Aerosol optical properties, then, were used to analysis the relationship between theoretical satellite measured radiation from radiative transfer calculations and aerosol optical thickness (AOT) under various environments (aerosol type and loadings). It is found that the choice of aerosol type makes little different in AOT retrieval for AOT<0.2. Otherwise AOT differences between true and retrieved increase as AOT increases. Furthermore, the differences between the AOT and angstrom exponent from standard algorithms and this study, and the comparison with ground based sunphotometer observations are investigated. Over the northeast Asian region, these comparisons suggest that spatially averaged mean AOT retrieved from this study is much better than from standard ocean color algorithm. Finally, these results will be useful for aerosol retrieval or atmospheric correction of COMS/GOCI data processing.

An Empirical Study on the Contextual Features of the Program Components during the Process of Social Work Program Design in the Social Service Agencies (사회복지 프로그램 구성요소개발활동의 실태 및 구성요소의 동질적인 범주성에 대한 실증적 연구 : 3단계 디자인 활동 중심으로)

  • Seo, In Hae;Kong, Gye Soon
    • Korean Journal of Social Welfare Studies
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    • v.44 no.3
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    • pp.237-269
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    • 2013
  • The purposes of the study are to describe the feature of the program components, and to identify their changes in the process of designing the social work programs in the community service agencies in Korea. In order to achieve these purposes, the researchers constructed an analytical framework including 24 program components derived from the related literatures. Data was collected by questionnaires answered by the social workers who were in charge of the program development and implementation. Descriptive statistics analysis and factor analysis were applied to exam the features of the program components in 195 social service programs developed by the funds from the Community Chest of Korea and a private funding foundation. As the result of the analysis, the three noticeable features are found; (1) the agencies have very actively involved in the designing work in the process of developing practice guideline, however they have less involved in the designing work in the process of implementing program; (2) program components which are low level in design activities are intervention models, staff education, and practical ethics; (3) 8 categories of components derived from the theoretical perspective are reduced to 6 categories in the process for developing practice guidelines, finally to 4 categories in the process for implementing the programs. The implications of major findings were discussed in academic and practical perspectives in Korea, including future research works in the area.

A Longitudinal Study of Factors Associated with Happiness in Primary School Children (학령기 아동의 행복감에 영향을 미치는 요인에 대한 종단 연구)

  • Lee, Jae-Kyeong;Cho, Hye-Chung
    • Journal of the Korean Society of Child Welfare
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    • no.40
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    • pp.41-71
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    • 2012
  • The purpose of this study is to examine longitudinal impacts of various factors on happiness in primary school children. Specifically, attachment theory and ecosystems perspective were utilized for the purpose of this study. We used Korea Youth Panel Survey, which is a 5-year longitudinal data collected from fourth grade in elementary school to second grade in middle school Latent growth model was employed as the analytic method. The findings of this study are as follow: first, academic achievement, self-esteem, parent attachment, peer attachment, teacher attachment, and community attachment all decreased over the 5-year study period. Also, the intercept and the slope variance of variables were found to be statistically significant. This means that there are significant differences in the intercept and the slope of individuals. Second, self-esteem, parent attachment, and peer attachment were found to have cross-sectional influences on happiness. This means that self-esteem, parent attachment, and peer attachment are positively associated with happiness at the intercept. Also, self-esteem, parent attachment, teacher attachment, and community attachment were found to have longitudinal influences on happiness. This means that the higher levels of community attachment at the intercept is associated with slower the rate of decrease in happiness at the slope. In addition, faster rates of decrease in self-esteem, parent attachment, teacher attachment, and community attachment are associated with faster the rate of decrease in happiness. Third, this study conducted multiple group analysis with gender. The findings of this analysis revealed no significant differences in analytic models between males and females. Based on these findings, theoretical and practice implications with regard to happiness in primary school children are discussed.

The effects on the personal characteristic of hospice volunteer the participation level of volunteer activities and durability (호스피스 자원봉사자의 성격특성이 자원봉사참여도 및 지속의지에 미치는 영향연구 - 자원봉사동기의 매개효과를 중심으로 -)

  • Lim, Seung-Hee;Roh, Seung-Hyun
    • Korean Journal of Social Welfare Studies
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    • v.40 no.3
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    • pp.125-148
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    • 2009
  • This study suggests hypothetic models and tests about the mediating effect of volunteer motivation which effects on the personal characteristic of hospice volunteer the participation level of volunteer activities and durability. Also, this study suggest a theoretical base for the seeking of hospice volunteer participation revitalization. This research participated 200 volunteers who attended the Autumn Conference in 2007 and 132 volunteers from five hospice organizations. The summary of research results is that the volunteer motivation of self-protection, career, social, understanding and value are endogenous variable and the 8 paths of Agreeable${\rightarrow}$self-protection, Agreeable${\rightarrow}$career, Neuroticism${\rightarrow}$career, Agreeable${\rightarrow}$social, Agreeable${\rightarrow}$understanding, Agreeable${\rightarrow}$value, Neuroticism${\rightarrow}$value, Extroversion${\rightarrow}$value valid. The path of social motivation${\rightarrow}$the participation level of volunteer activities, understanding motivation ${\rightarrow}$ the participation level of volunteer activities, value motivation${\rightarrow}$the participation level of volunteer activities are valid in the participation level of volunteer activities as an endogenous variable. The path of understanding motivation ${\rightarrow}$ the durability level of volunteer activities, value motivation ${\rightarrow}$ the durability level of volunteer activities, the participation level of volunteer activities ${\rightarrow}$ the durability level of volunteer activities are valid in the durability level of volunteer activities as an endogenous variable. Also, this study test the mediating effect an attended direct effect as the central figure and based on the these results, the revitalizations of hospice volunteer participant are suggested as an proposal.

A Study on Economic Value Analysis Model of Meteorological Information (기상정보의 경제적 가치 분석모형 연구)

  • Kim, Sung Tai
    • Journal of Convergence for Information Technology
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    • v.9 no.11
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    • pp.103-109
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    • 2019
  • The purpose of this study is to examine various existing models that analyze the economic value of meteorological information, to present a new analysis model, a market model, and to quantitatively analyze the economic value of meteorological information in the Korean service industry using the market model. The research method of this paper will basically use empirical analysis along with the theoretical approach to critically examine the existing analytical model of economic value of meteorological information and to suggest a new analytical model. The analysis results are as follows. Theoretically, the marginal cost of firms is reduced by providing the amount of weather information, and social welfare is increased by the increase of consumer and producer surplus. In this paper, the marginal cost of 1% increase in the amount of weather information decreases by 0.101% and the increase in social welfare increases by 1,247billion Won in 2017. On the other hand, in the accommodation and restaurant sectors, the marginal cost due to a 1% increase in weather information decreased by 0.218%, and the social welfare increase increased by 308billion Won in 2017.

Effectiveness of multi-mode surface wave inversion in shallow engineering site investigations (토목관련 천부층 조사에서 다중 모드 표면파 역산의 효과)

  • Feng Shaokong;Sugiyama Takeshi;Yamanaka Hiroaki
    • Geophysics and Geophysical Exploration
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    • v.8 no.1
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    • pp.26-33
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    • 2005
  • Inversion of multi-mode surface-wave phase velocity for shallow engineering site investigation has received much attention in recent years. A sensitivity analysis and inversion of both synthetic and field data demonstrates the greater effectiveness of this method over employing the fundamental mode alone. Perturbation of thickness and shear-wave velocity parameters in multi-modal Rayleigh wave phase velocities revealed that the sensitivities of higher modes: (a) concentrate in different frequency bands, and (b) are greater than the fundamental mode for deeper parameters. These observations suggest that multi-mode phase velocity inversion can provide better parameter discrimination and imaging of deep structure, especially with a velocity reversal, than can inversion of fundamental mode data alone. An inversion of the theoretical phase velocities in a model with a low velocity layer at 20 m depth can only image the soft layer when the first higher mode is incorporated. This is especially important when the lowest measurable frequency is only 6 Hz. Field tests were conducted at sites surveyed by borehole and PS logging. At the first site, an array microtremor survey, often used for deep geological surveying in Japan, was used to survey the soil down to 35 m depth. At the second site, linear multichannel spreads with a sledgehammer source were recorded, for an investigation down to 12 m depth. The f-k power spectrum method was applied for dispersion analysis, and velocities up to the second higher mode were observed in each test. The multi-mode inversion results agree well with PS logs, but models estimated from the fundamental mode alone show f large underestimation of the depth to shallow soft layers below artificial fill.

The Effect of the Entrepreneurial Motivation in Women Entrepreneurs on Entrepreneurial Satisfaction Mediated by Entrepreneurial Orientation and Commitment to Start-up (여성창업자의 창업동기가 기업가지향성과 창업의지를 매개로 창업만족도에 미치는 영향)

  • Lee, Sun Hyup;An, Eun Jae
    • Journal of Korea Society of Industrial Information Systems
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    • v.23 no.6
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    • pp.95-112
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    • 2018
  • This study aims to examine their influential relations between the start-up motivation and entrepreneurial satisfaction of women entrepreneurs mediated by entrepreneurial orientation and commitment to start-up. An empirical analysis of the 386 questionnaires collected by the cosmetics store entrepreneurs located in Seoul and Gyeonggi provinces were conducted in this study. Mediator effect use the comparison by correspondence with total effect, direct effect, indirect effect inclusive of characteristic indirect effect. To achieve the research goal, this study were analyzed on the cornerstone of combination of parallel serial mediation models with entrepreneurial orientation and commitment to start-up as mediator variable. The following is the results verified through this study. First, Rewards motivation had the significant positive effects on the entrepreneurial satisfaction in total effects of X on Y and direct effects of X on Y. Second, Achievement motivation had the positive effects on entrepreneurial satisfaction in characteristic indirect effects of X on Y. Third, Environment motivation had the significant positive effects on the entrepreneurial satisfaction in total effects of X on Y and direct effects of X on Y. Fourth, The entrepreneurial orientation and the commitment to start-up between the start-up motivation and entrepreneurial satisfaction in women entrepreneurs had the serial mediation effects. I discussed theoretical and empirical implications with these findings and described the future research.

Development of a High Performance Ocean Model using Julia Language (줄리아 언어를 이용한 고성능 해양모델의 개발)

  • KWON, MIN-SUN;KIM, JONG GU
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.24 no.2
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    • pp.187-207
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    • 2019
  • In order to develop a high performance ocean model, we used Julia, a Just-In-Time compile language, and to obtain the solution of the momentum equation, we made the code to solve the Poisson equation by the Successive Over-Relaxation method. And then we made two models to test Julia calculation codes. First, a simple channel form is modeled to test constant source/sink conditions. Second, the simplified Yellow Sea was modeled to test tidal forcing, Coriolis forces, and the effect of vertical eddy diffusivity coefficients. The model has been tested with a total of eight cases in the two scenarios. As a result of the test, the depth-averaged current speed of the three cases in Scenario 1 converged perfectly to the theoretical value, and that showed well a vertical flow velocity gradient due to the bottom friction. Also, the result of Scenario 2 represented well the amphidromic points of Yellow Sea and the tidal characteristics of mid-western and southwestern coast of Korea. Therefore, it is considered that the ocean model using Julia language has developed successfully, this suggests that the ocean model has come to the stage of successful transition from a classical compile language to a Just-In-Time compile language.

A Stratified Mixed Multiplicative Quantitative Randomize Response Model (층화 혼합 승법 양적속성 확률화응답모형)

  • Lee, Gi-Sung;Hong, Ki-Hak;Son, Chang-Kyoon
    • Journal of the Korean Data Analysis Society
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    • v.20 no.6
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    • pp.2895-2905
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    • 2018
  • We present a mixed multiplicative quantitative randomized response model which added a unrelated quantitative attribute and forced answer to the multiplicative model suggested by Bar-Lev et al. (2004). We also try to set up theoretical grounds for estimating sensitive quantitative attribute according to circumstances whether or not the information for unrelated quantitative attribute is known. We also extend it into the stratified mixed multiplicative quantitative randomized response model for stratified population along with two allocation methods, proportional and optimum allocation. We can see that the various quantitative randomized response models such as Eichhorn-Hayre's model (1983), Bar-Lev et al.'s model (2004), Gjestvang-Singh's model (2007) and Lee's model (2016a), are one of the special occasions of the suggested model. Finally, We compare the efficiency of our suggested model with Bar-Lev et al.'s (2004) and see that the bigger the value of $C_z$, the more the efficiency of the suggested model is obtained.

Does Pygmalion Leadership Play a Role in the Process of Public Organization members' Self-Efficacy and Organizational Commitment to Customer Orientation? (공공조직 구성원의 자아효능감과 조직몰입이 고객지향성에 미치는 과정 중 피그말리온 리더십이 작용하는가?)

  • Na, Kyung-Soo
    • The Journal of the Korea Contents Association
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    • v.21 no.10
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    • pp.356-367
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    • 2021
  • This study is a study on how much organizational leadership influences customer orientation so that it can secure and maintain a continuous competitive advantage in the rapidly changing environment of corporate management and public organizations. it was approached through theoretical consideration of pygmalion leadership. The purpose of this study is as follows. First, a conceptual definition of the three research variables of pygmalion leadership and its constituent atmosphere, feedback, and output is given. Second, the casual relationship between the conceptually defined three research variables of pygmalion leadership and self-efficacy and organizational commitment was verified. Third, the casual relationship was verified on the extent to which pygmalion leadership influences customer orientation through self-efficacy and organizational commitment, which are parameters. Fourth, through the verification result of the casual relationship between the research variables constituting the research model of this study. It was intended to present an implication. In addition, the significance of direct causal relationships between the research variables of pygmalion leadership, mediating variables, and dependent variables, which constitute the verified research models was verified, and the results of hypothesis testing were presented, and the academic and practical implications of the results of this study were presented.