• Korea journal of population studies
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• v.19 no.1
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• pp.139-159
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• 1996

This study comparatively examines a causal model of employee attatchment which focuses on employee's organizational commitment and intent to stay with an organization. This study is based on two separate studies of employee attachment among teachers : the U.S. case of the Chicago Public Schools (CPS) and the South Korean case of the Seoul Educational District (SED). The main purpose of this study is to replicate in Korea the CPS study. A revised model based on the unique characteristics of Korean teachers is also developed and estimated. The Price Mueller model of employee attachment provides the basic theoretical framework for this study. It includes five general classes of variables : 1) employee responses to work variables : job satisfaction, commitment, and intent to stay; 2) psychological stress variables: role ambiguity, role conflict, work overload, and quality of students; 3) social structural variables: autonomy, routinization, distributive justice, and legitimacy; 4) economic structural variables: pay, job security, promotional opportunities, and job opportunities; and 5) work orientation variables : career commitment, normative commitment, work motivation, affectivity, work values, and met expectations. The data was collected through questionnaire survey and a sample of 649 secondary school teachers in Seoul, South Korea, was included in the final analysis. Covariance structure analysis (LISREL) was used to estimate the causal model. The results indicate that the endogenous variables of job satisfaction and commitment play a considerably less important role than in the U.S. model in mediating the effects of the exogenous variables on intent to stay, and the model fails to explain the majority of the variance in intent to stay. In addition, the new variables added to the revised Korean model do not bave significant effects on intent to stay. The structural characteristics of the employment relationship and labor markets associated with Korean teachers forced mobility and closed external markets - are largely accountable for the major differences between the Korean and the U.S. cases. The study suggests that conceptual and empirical work on what produces employee attachment under these structural constraints needs to receive more attention in future studies.

• Journal of Korean Society of Transportation
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• v.31 no.1
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• pp.65-76
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• 2013

Traffic accidents at signalized intersections have been increased annually so that it is required to examine the causation to reduce the accidents. However, the current existing accident models were developed mainly by using non-linear regression models such as Poisson methods. These non-linear regression methods lack to reveal the complicated causation for traffic accidents, though they are the right choice to study randomness and non-linearity of accidents. Therefore, it is required to utilize another statistical method to make up for the lack of the non-linear regression methods. This study developed accident prediction models for 4 legged signalized intersections with Poisson methods and compared them with structural equation models. This study used structural equation methods to reveal the complicated causation of traffic accidents, because the structural equation method has merits to explain more causational factors for accidents than others.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2012.05a
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• pp.159-170
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• 2012

본 연구는 다음과 같은 분석결과를 제시한다. 먼저 우리나라 10개 산업의 기술생태지형을 결정하는 상호관계 K는 9개로 나타났다. 이러한 주성분요인분석결과는 K=N-1의 기술생태지형 구조를 가지고 있음을 보여준다. 둘째, Kauffman NK모형에 따른 우리나라 기술생태지형은 K=N-1인 경우로 다 극점을 존재하는 적응체계로 매우 울퉁불퉁한 기술생태지형을 가지고 있다고 볼 수 있다. 따라서 우리나라의 기술생태계경우에 기술 또는 산업의 수 N이 증가함에 따라서 국소 최적 점의 수는 매우 빠르게 증대할 수 있다. 이러한 매우 많은 국소 최적 점을 가진 기술생태지형에서 기술탐색과정은 전체 최적 기술조합 또는 기술개발에 효율적으로 도달하기 어려우며, 역시 기술생태지형은 매우 복잡한 진화 및 발전체계를 갖고 있음을 의미한다. 본 연구결과의 기술 정책적 시사점은 우리나라 산업간 그리고 기술간에 보다 상호연관성을 높임으로써, 기술생태지형을 완만하고 매끄럽게 조성할 필요성이 제기된다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.443-454
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• 2020

The purpose of this study is to propose a structural theoretical model that can explain the learning flow of online distance education participants and to clarify the structural causal relationship among related variables that affect the learning flow of cyber university learners. Study results found a modified final model with a statistically significant fit based on the structural research model proposed in this study explained the learning flow of cyber university learners. Second, as a result of verifying the relationship between learning motivation and learning flow of cyber university learners, it was found that intrinsic motivation had a significant positive effect on learning flow. Third, as a result of the empirical verification on the relationship between academic self-efficacy and learning flow of cyber university learners, it was found that academic self-efficacy had a significant effect on learning flow. Fourth, as a result of empirical verification on the relationship between self-directed learning and the learning flow of cyber university learners, it was found that the learner's self-directed learning ability had a significant effect on learning flow. Such research results can be used to suggest a strategic direction for successful settlement and diffusion of a new paradigm of online non-face-to-face distance education, which has recently attracted attention.

• Informatization Policy
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• v.22 no.3
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• pp.36-46
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• 2015

This study verified theoretical model to explain adolescents' addictive use of smartphone. I used the data of 679 middle and high school students among 2013 internet addiction survey of National Information Society Agency(NIA). This study utilized structural equation modeling analysis to compare a suggestive model and alternative model. According to the final model, higher the satisfaction of family relationship, the addictive use of smartphone and emotional problems of adolescents were reduced. And, higher the addictive use of smartphone, higher the emotional problems of adolescents. Also, family relationship affects emotional problems via addictive use of smartphone. While, in the alternative model, path from amount of smartphone use to addictive use of smartphone was not significant. Results of this study suggest that family relationship variable may play an antecedent factor of addictive use of smartphone and emotional problems of adolescents and control of smartphone use is important to keeping a mental health of adolescents.

• The Korean Journal of Financial Management
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• v.20 no.2
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• pp.41-72
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• 2003

The purposes of this paper are to build theoretical and empirically testable model to identify determining factors of ownership structure, and to analyze this model empirically using th Korea Stock Exchange panel data, and to test the impact of opening the stock market on the determinants of ownership structure. The determining factors of ownership structure identified in this paper include debt ratio, dividend, asset characteristics, profitability, growth business risk, size, institutional investors and chaebol-non chaebol dummy variable. Empirical panel estimation test reveals that this model can explain about $9\sim11%$ of the cross sectional variance in the equity ratio of large shareholders. The reasons that this model has too explanatory power are that some variables were measured with errors, and that there were some omitted variables in tested model. The regression results on the model variables ar generally in line with predictions. But the coefficient estimates on size is never significant. And it appears that the exogenous variable which explains opening the stock market has positive effect on the determinants of ownership structure.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1992.04b
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• pp.457-465
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• 1992

현재 또는 장래에 예견되는 거의 모든 통신서비스를 통합적으로 제공할 수 있는 B-ISDN환경하에서 음성통화와 비디오정보, 데이타들이 각기 다른 bit rate와 서비스 요구조건(통화시간, 질등)를 가지고 전송서비스를 받으려 하기때문에 매우 다양한 서비스들의 조합을 고려하여 교환시스팀을 구현해야 한다. B-ISDN에 적합한 전송기술로서 ATM(Asynchronous Transfer Mode)이 일반적으로 제안되고 있는데 이미 10여종의 독특한 ATM시스팀들이 이론적, 실험적 연구단계를 거쳐 거의 실용화 단계까지 이르렀다고 주장되고 있다. 본 논문에서는 ATM교환시스팀의 설계요건과 비교기준을 제시하여 설계 대자인을 주어진 기술제약하에 최적화 할 수 있는 조건을 제시한다. 이때 우선 기본 스위치의 구조를 단단계로 할 것인가 다단계로 할 것인가에 대한 정량적, 확률적인 비교가 행해지고 특히 이미 많은 ATM스위치에서 채택되고 있는 Banyan형태의 망의 성능분석을 보다 현실에 근접하게 할 수 있는 이산적 마코프체인에 의한 모형과 계산방법이 확립된다. 이를 통해 단위스위치내부에 버퍼의 유무, 버퍼를 두는 위치, 또한 버퍼사이즈에 의한 영향등이 세부적으로 분석된다.

• KDI Journal of Economic Policy
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• v.16 no.3
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• pp.69-96
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• 1994

본(本) 연구(硏究)는 국내(國內) 증시개방(證市開放)이 원화환율(貨換率)에 미친 영향(影響)에 대하여 이론적(理論的)인 모형(模型) 제시(提示)와 함께 실증분석(實證分析)을 시도하였다. 시간변동계수모형(時間變動係數模型)을 이용한 환율방정식(換率方程式) 추정결과에 의하면 1980년대 말 이후부터 증시(證市)를 통한 해외자금 유출입에 직접적인 영향을 주는 국내외(國內外) 주식수익율(株式收益率) 격차(隔差)의 환율절상효과(換率切上效果)가 지속적으로 증가(增加)한 것으로 나타났다. 반면 80년대에 걸쳐 주된 환율결정요인이었던 경상수지(經常收支)는 90년대 들어 환율변동에 미친 영향력이 현저하게 약화(弱化)된 것으로 나타났다. 이는 외환(外換)및 자본규제정책(資本規制政策)의 변화 등 구조변화(構造變化)에 기인된 현상으로 판단되며, 90년대에 들어서면서 환율(換率)이 경상수지보다는 경상수지와 자본수지를 더한 종합수지(綜合收支)에 더 큰 영향(影響)을 받고 있음을 의미한다. 위의 분석결과는 증시의 추가개방 등 자본자유화가 확대될 경우 원화절상압력(貨切上壓力)이 가중되고 이에 따른 수출경쟁력(輸出鏡爭力) 약화(弱化)로 종합수지(綜合收支)는 흑자(黑字)를 기록하면서 경상수지(經常收支) 적자(赤字)가 크게 늘어날 가능성이 있음을 시사한다. 따라서 수출경쟁력(輸出競爭力)을 유지하기 위해서는 실질실효환율(實質實效換率)기준으로 원화환율이 안정될 수 있도록 안정적(安定的)인 재정(財政) 통화운용(通貨運用)으로 대응해야 할 것이다.

• Korean Journal of Social Welfare
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• v.59 no.2
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• pp.89-114
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• 2007

The purposes of this study were : (1) to find out subjective well-being structural model of people with disabilities, (2) to compare the female's subjective well-being structural model with male's. Based on previous researches related to subjective well-being of non-disabled, I applied a integrative model of bottom-up and top-down theories to subjective well-being of people with disabilities. Data were gathered from 497 persons with disabilities(253 males and 244 females) in Korea. This research shows that the female's level of life satisfaction is not different to male's. In female group, the objective life conditions(the level of education, family income, and to have jobs or not) and self esteems are important variables in subjective well-being structural equation model. In male group, on the other side, recognition about social support level is important variable. Various theoretical and practical implications for social work practice were discussed.

• KDI Journal of Economic Policy
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• v.13 no.4
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• pp.117-140
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• 1991

The purpose of this paper is primarily to introduce a nonparametric statistical tool developed by Baek and Brock to detect a unidirectional causal ordering between two economic variables and apply it to interesting macroeconomic relationships among money, production and prices. It can be applied to any other causal structure, for instance, defense spending and economic performance, stock market index and market interest rates etc. A key building block of the test for nonlinear Granger causality used in this paper is the correlation. The main emphasis is put on nonlinear causal structure rather than a linear one because the conventional F-test provides high power against the linear causal relationship. Based on asymptotic normality of our test statistic, the nonlinear causality test is finally derived. Size of the test is reported for some parameters. When it is applied to a money, production and prices model, some evidences of nonlinear causality are found by the corrected size of the test. For instance, nonlinear causal relationships between production and prices are demonstrated in both directions, however, these results were ignored by the conventional F-test. A similar results between money and prices are obtained at high lag variables.