• Journal of Preventive Medicine and Public Health
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• v.56 no.4
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• pp.303-311
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• 2023

Traditional mediation analysis, which relies on linear regression models, has faced criticism due to its limited suitability for cases involving different types of variables and complex covariates, such as interactions. This can result in unclear definitions of direct and indirect effects. As an alternative, causal mediation analysis using the counterfactual framework has been introduced to provide clearer definitions of direct and indirect effects while allowing for more flexible modeling methods. However, the conceptual understanding of this approach based on the counterfactual framework remains challenging for applied researchers. To address this issue, the present article was written to highlight and illustrate the definitions of causal estimands, including controlled direct effect, natural direct effect, and natural indirect effect, based on the key concept of nested counterfactuals. Furthermore, we recommend using 2 R packages, 'medflex' and 'mediation', to perform causal mediation analysis and provide public health examples. The article also offers caveats and guidelines for accurate interpretation of the results.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.151-157
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• 2013

Since the sub-prime mortgage crisis from the US in 2008, the Korean housing market has plummeted. However, the deposit prices of the Korean local lease contract, Chonsei, had been increasing. This increase of Chonsei prices can be a threat to low-income people, most of whom prefer to live in houses with a Chonsei contract. In the housing and Chonsei market, there are many stakeholders with their own interest, hence, simple thoughts about housing and Chonsei market, such as more house supply, will decrease house price, would not work in a real complex housing market. In this research, we suggests system dynamics conceptual model which consists of causal-loop-diagrams for the Chonsei market as well as the housing market. In conclusion, the Chonsei price has its own homeostasis characteristics and different price behavior with housing price in the short and long term period. We found that unless government does not have a structural causation mind in implementing policies in the real estate market, the government may not attain their intended effectiveness on both markets.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.790-799
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• 2010

The Upper Devonian Grossmont Formation in Alberta, Canada reserves an estimated 50 billion cubic meters of bitumen and possess about 1/6 of the total bitumen resources in northern Alberta. However, unlike the overlying Athabasca oil sands, non conventional bitumen resources has not been developed as yet. The carbonate rocks of Grosmont Formation have been subject to various stages of diagenesis, including dolomatization and karstification with a strong effect on the distribution of porosity and permeability, which resulted in highly heterogeneous reservoirs. An extensive fracture logging and mapping was performed on total of six boreholes located in the study area to explore the characteristics of fracture geometry system and the subsurface structures of carbonates reservoir that holds bitumen. Fractal dimension was used as a measure of the statistical homogeneity of the fractured rock masses. The applicability of random Cantor dust, Dc, as a fractal parameter was examined systematically. The statistical homogeneity of fractured carbonates rock masses was investigated in the study area. The structural domains of the rock masses were delineated depthwise according to estimated Dc. The major fracture orientation was dominated by horizontal beddings having dip of $0-20^{\circ}$. Also, fractures having high dip angles existed with relatively low frequency. Three dimensional fracture network modeling for each structural domain has been performed based on fracture orientation and intensity, and some representative conceptual models for carbonates reservoir in the study area has been proposed. The developed subsurface conceptual models will be used to capture the geomechanical characteristics of the carbonates reservoir.

• The Journal of the Korea Contents Association
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• v.11 no.7
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• pp.374-386
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• 2011

This study investigated the impact of leader's coaching on job satisfaction and job involvement. In particular, this study examined employees' self-efficacy as a mediator in the relationship between leader's coaching and job satisfaction and job involvement. On the basis of theoretical linkages between the constructs, a conceptual model and hypotheses were established. Empirical data were collected by using a set of questionnaires. This survey was administered to employees working in 20 firms. 269 samples were used for the analysis. This study conducted a exploratory factor analysis and confirmatory factor analysis for the validity test, structural equation modeling(SEM) was employed to test the hypothesized relationships in the conceptual model. This study shows that the proposed model is reasonably fit to the actual data. From these analyses, the following results were obtained. First, leader's coaching is positively related to employees' self-efficacy. Second, leader's coaching is positively related to job satisfaction and job involvement. Third, employees' self-efficacy has partially mediated effects on the relationship between leader's coaching and job satisfaction and job involvement.

• The Journal of the Korea Contents Association
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• v.14 no.5
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• pp.309-321
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• 2014

Existing research indicates that job design influences not only a worker's psychological well-being but also the individual and organizational performance. This study has been motivated by the need to provide useful implications for increasing the efficiency of business operations. The purpose of this research is to investigate the relationships between job characteristics and performance factors in the domestic financial industry. The conceptual framework has been developed based on Hackman & Oldham's job characteristics model and the related literature. We conducted a survey of employees in the domestic financial firms to test the conceptual model and hypotheses, and analyzed the data using the structured equation modeling method. The results of the empirical analysis indicate that the variety and autonomy of a job positively affect corporate innovation, confidence, and job satisfaction and that corporate innovation and job satisfaction positively influence job commitment. This research designed to examine the relationship between job characteristics and organizational performance will make a contribution to the improvement of business efficiency in our society.

• Journal of the Korean Society of Costume
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• v.58 no.4
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• pp.58-71
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• 2008

The demand for personalized products and service of apparel product has increased dramatically. In order to acquire a personalized apparel product, consumers may have to sacrifice more expense or time. The purpose of this study was to investigate various personalization strategies in apparel business and to identify antecedents that influence the process. Clothing involvement and two price related variables (clothing expense and willingness to pay more) were included in the study as antecedents. Four personalization strategies were included in the study: design selection, size customization, in-store service and promotion personalization. For an empirical study, a conceptual model was designed and research questionnaire was developed. A measure of personalization of apparel shopping was developed based on existing scale items of prior research and a pilot study. Data from 766 men and women in their twenties to forties were used for statistical analysis. Structural Equation Modeling was used for the data analysis. Results indicated that the conceptual model was a good fit to data. Structural paths indicated that there was significant influence of clothing involvement on design selection and sales promotion personalization strategies. Involved consumers spent more on chothing products and were likely to pay more on personalized products and services. Monthly clothing expense influenced size customization significantly. It also had negative influence on service related personalization strategies. Consumers were willing to pay more when it comes to product related personalization strategies such as design and size but not necessarily to service related strategies. This study was an attempt to provide an in-depth and synthesized approach on consumer attitudes toward personalization of apparel products.

• Archives of design research
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• v.18 no.2 s.60
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• pp.273-282
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• 2005

In this study, we proposed Context Cube as a conceptual model of user context, and a Multi-modal Interaction Design framework to develop ubiquitous service through understanding user context and analyzing correlation between context awareness and multi-modality, which are to help infer the meaning of context and offer services to meet user needs. And we developed a case study to verify Context Cube's validity and proposed interaction design framework to derive personalized ubiquitous service. We could understand context awareness as information properties which consists of basic activity, location of a user and devices(environment), time, and daily schedule of a user. And it enables us to construct three-dimensional conceptual model, Context Cube. Also, we developed ubiquitous interaction design process which encloses multi-modal interaction design by studying the features of user interaction presented on Context Cube.

• Journal of the Korean Society for information Management
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• v.34 no.4
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• pp.201-225
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• 2017

In this study, based on the analysis of FRBRoo, we tried to propose suggestions to expand and improve the FRBR family conceptual model. FRBRoo is a plug-in ontology of CIDOC CRM with cooperation of museum field. As FRBR family models also revised and integrated into IFLA Library Reference Model, the additional analysis on IFLA LRM was performed. If bibliographic information is required to support the technical and user services of the library, the way to analyze the bibliographic information should be improved in order to cope with the new challenges faced by the library. To do this, time-related event concepts should be reflected in the modeling of bibliographic information. It is also necessary to expand the creation and exchange unit of bibliographic information to smaller units or larger units than legacy bibliographic records. Using FRBRoo as a linkage tool for the sharing of bibliographic information is also suggested.

• Journal of KIISE:Computing Practices and Letters
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• v.5 no.4
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• pp.385-394
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• 1999

제품을 설계하는 디자이너나 엔지니어는 많은 시간과 노력을 들이지 않고서 그들이 설계한 3차원 제품 모델에 대한 사실적인 이미지를 원한다. 디자인 프로세스의 초기인 개념 설계에서부터 설계검증, 그리고 가공 과정에서 사실적인 이미지가 매우 유용하므로, 대부분의 주요 CAD 제작사는 그들의 CAD 소프트웨어에 고급 렌더링 기능을 추가하고 있다. 상용의 CAD/CAM 모델러에서는 NURB 곡면을 기초로 모델링을 수행하므로, NURB 곡면을 렌더링할 수 있는 패키지가 필요하다. VIF(Visual InterFace) 렌더링 라이브러리는 A-buffer 방식과 Ray tracing 방식의 두 가지 고급 렌더링 모드를 제공한다. 다각형은 물론 NURB 곡면을 입력으로 받아 사용자가 설정한 표면의 각종 계수, 원하는 view와 설정된 광원에 따라 이미지를 만들고 다양한 형태로 출력시킬 수 있는 다양한 기능을 제공한다. 본 논문에서는 VIF 렌더링 라이브러리에 대한 구조와 기능별로 분류된 함수에 대하여 설명하며, 실제로 CAD/CAM 시스템과 통합되어 구상설계에서부터 3차원 설계 모델링에 이르기까지의 제조공정에서 설계검증 툴로써 어떻게 활용되고 있는가에 대하여 기술한다.Abstract Engineers and industrial designers want to produce a realistic-looking images of a 3D model without spending a lot of time and money. Photo-realistic images are so useful from the conceptual design, through its verification, to the machining, that most major CAD venders offer built-in as well as add-on photo-realistic rendering capability to their core CAD software. Since 3D model is consists of a set of NURB surfaces in commercial CAD packages, we need a renderer which handles NURB surface as well as other primitives.A new rendering library called VIF (Visual InterFace) provides two photo-realistic rendering modes: A-buffer and Ray tracing. As an input data it takes NURB surfaces as well as polygonal data and produces images in accordance with the surface parameters, view and lights set by user and outputs image with different formats. This paper describes the overall architecture of VIF and its library functions classified by their functionalities, and discusses how VIF is used as a graphical verification tool in manufacturing processes from the conceptual design to 3D modeling.

• The Journal of the Korea Contents Association
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• v.10 no.1
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• pp.353-364
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• 2010

The purpose of this study is to examine the effect of leader-member exchange(LMX) on employee's affective commitment and continuance commitment focusing on the mediating role of job stress. On the basis of theoretical linkages between the constructs, a conceptual model and hypotheses were established. The sample included 482 employees. Structural equation modeling(SEM) was employed to test the hypothesized relationships in the conceptual model. This study shows that the proposed model is reasonably fit to the actual data. Empirical results indicate that LMX has a negative impact on employee's job stress, has a positive impact on employees' affective commitment and continuance commitment. Employees' job stress has partially mediated effect on the relationship between LMX and employees' affective commitment, but has not mediated effect on the relationship between LMX and employees' continuance commitment.