• Title/Summary/Keyword: Model Equation

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An Analysis about of Path Coefficient Difference of Intention to Use between Smart Education Experience Group and Non-Experience Group (스마트 교육 경험 집단과 비 경험 집단 간 활용 의도 경로계수 차이 분석)

  • Kim, Sang-Yon
    • Journal of The Korean Association of Information Education
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    • v.16 no.4
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    • pp.383-395
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    • 2012
  • This study investigated the recognition of teachers on the introduction and use of SMART education, which is an ICT-based customized learning method. Through the investigation, the study was to empirically examine the relationship between the use intention of SMART education and its influential factors, and analyze the difference in the use intention of SMART education by teachers, focusing on the experience of SMART education. For analysis purpose, a structural equation model, which was expanded from the theory of reasoned action, was presented. In addition, the difference in path coefficient, which affects the use intention of SMART education, was compared based on the experience with or without SMART education. The results showed that teacher efficacy in the teacher group without SMART education experience was more negatively significant in class burden. In the teacher group with SMART education experience, it was found that the attitude toward SMART education was more significant in use intention; organizational citizenship behavior was more significant in use intention; teacher efficacy was more significant in the attitude toward SMART education and; teacher efficacy was more significant in organizational citizenship behavior. No significant difference was found in the path coefficient among the groups in other hypotheses. Through these results, the factors for introducing and promoting SMART education and its invigoration measures were presented.

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Development of high performance and low noise axial-flow fan for cooling machine room of refrigerator using airfoil-cascade analysis and surface ridge shape (익렬 분석 및 표면 돌기 형상을 이용한 냉장고 기계실 냉각용 고성능/저소음 축류팬 개발)

  • Choi, Jinho;Ryu, Seo-Yoon;Cheong, Cheolung;Kim, Tae-hoon;Koo, Junhyo
    • The Journal of the Acoustical Society of Korea
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    • v.39 no.6
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    • pp.515-523
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    • 2020
  • This study aims to improve the flow and noise performances of an axial-flow fan for cooling the machine room in a refrigerator by using airfoil-cascade analysis and surface ridge shape. First, the experimental evaluations using a fan performance tester and an anechoic chamber are performed to analyze the flow and noise performances of the existing fan system. Then, the corresponding flow and noise performances are numerically assessed using the Computational Fluid Dynamics (CFD) techniques and the Ffowcs-Williams and Hawkings (FW-H) equation, and the validity of numerical results are confirmed through their comparisons with the experimental results. The analysis for the flow of a cascade of airfoils constructed from the existing fan blades is performed, and the pitch angles for the maximum lift-to-drag ratio are determined. The improved flow performance of the new fan applied with the optimum pitch angles is confirmed. Then, the fan blades with surface ridges on their pressure sides are devised, and the reduction of aerodynamic noise of the ridged fan is numerically confirmed. Finally, the prototype of the final fan model is manufactured, and improvements in the flow and noise performances of the prototype are experimentally confirmed.

Age and Growth of the Robust Tonguefish, Cynoglossus robustus in the Southern Sea of Korea (한국 남해안 개서대 Cynoglossus robustus의 연령과 성장)

  • Seo, Young Il;Kim, Joo Il;Oh, Taeg Yun;Lee, Sun Kil;Kim, Sung Tae;Joo, Hyun
    • Korean Journal of Ichthyology
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    • v.19 no.4
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    • pp.324-331
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    • 2007
  • Age and growth of the robust tonguefish, Cynoglossus robustus were estimated using scale of 353 fish specimens from February, 2004 to December, 2005 in the Southern Sea of Korea. Marginal increment of the scale formed annual rings from October to November at the beginning of autumn season. In the relationship between total length and body weight, a multiplicative error structure was assumed because variability in growth increased as a function of the length, and the estimated equation was $BW=0.0013TL^{3.399}$ ($R^2=0.916$). The relative growth as body weight at total length has significant difference between females and males (p<0.05). For describing growth of the robust tonguefish, C. robustus a von Bertalanffy growth model was adopted. The von Betalanffy growth curve had a additive error structure and the growth parameters estimated from Walford method were $L_{\infty}=43.77cm$, K=0.186/year and $t_0=-2.295year$. Growth at age of females and males shows no significant difference (P>0.05).

Relationship between Peer Interaction, Self-regulation and Leadership of Young Children: Analysis on Mediating Effect of Self-Regulation (유아의 또래 상호작용, 자기조절과 리더십간의 관계 연구: 자기조절의 매개효과 분석)

  • Park, Mi Suk;Ahn, Hyo Jin
    • Korean Journal of Childcare and Education
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    • v.11 no.4
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    • pp.1-17
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    • 2015
  • The purpose of this study is to investigate the relationship between peer interaction, self-regulation and leadership of young children, and examine the mediating effect of self-regulation ability in the effect of peer interaction on the leadership of young children. The subjects of the study were 211 children aged 4 to 5 who attended in child education institutes in the Seoul-Incheon area. A survey was conducted on teachers who worked in kindergartens and day care centers with questionnaires, and the collected data were analyzed. For data analysis, SPSS WIN 21 program was used to calculate mean, standard deviation, skewness, and kurtosis, and correlation analysis was conducted. Also, the structural equation model was validated using Amos 21, and the following results were obtained. First, the positive peer interaction, self-regulation and leadership of children were positively associated. Second, the peer interaction did not have a significant effect on the leadership of young children, and the self-regulation of young children had a positive effect on the leadership of young children. It was found that peer interaction had a positive effect on the self-regulation of young children, and in the relationship of effects on the leadership of young children, the self-regulation was found to play a role of significant mediating effect. Such results are remarkable elements in leadership education for young children, implying the importance of peer interaction and self-regulation of young children.

The Relationship between Adult Interpersonal Traumatic Experience and Posttraumatic Growth : The Multiple Mediating Effect of Optimism and Quality of Relationship (성인의 대인외상경험과 외상 후 성장의 관계 : 낙관성과 관계의 질의 다중매개효과)

  • Park, Euna
    • Korean Journal of Social Welfare
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    • v.67 no.1
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    • pp.263-288
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    • 2015
  • This study is to research the mediating effects of optimism and quality of relationship which interpersonal traumatic experience influences posttraumatic growth. It focuss on verifying the impact of interpersonal traumatic experience to optimism and quality of relationship and the influence of optimism and quality of relationship to posttraumatic growth. And also it is to verify dual mediating effect between optimism and quality of relationship. Data for this study were collected through the use of a survey instrument completed by 405 interpersonal traumatic experience, 30-60 age group. Collected data were analysed by AMOS program, Structure Equation Model(SEM) was implemented to verify the mediating effect between optimism and quality of relationship. Finally, Phantom Variable was utilized for verification of indirect influence of a multi mediating effects. The findings of this study were as follows, First, the result shows that the higher level interpersonal traumatic experience, the higher posttraumatic growth they have. Second, it shows that optimism and quality of relationship have partial mediating effect between interpersonal traumatic experience and posttraumatic growth. Third, it was analyzed that optimism and quality of relationship had double mediating effect. Based on these findings, the research discussion reinforced the importance of intervene with its optimism and quality of relationship in the site of those who experience interpersonal trauma. Theological, political and practical implications of this study are as follows. First, it has a series of significance in terms of that this study confirmed its influence considering the quality of relationship from interpersonal experience among relevant factors of traumatic accident, optimism among individual factors, quality of relationship among environmental factors based on 'the crisis of life and the theory of individual growth'. econd, even though optimism and quality of relationship were proved as major predictors for posttraumatic growth of those who experience interpersonal traumatic, psychological support center for traumatic experience is not operated systematically in Korea. Third, this study implies that it should intervene mainly with its optimism and quality of relationship in the site of those who experience interpersonal trauma such as any abuses including sexual abuse, bullying, and divorce.

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Uniform Hazard Spectrum for Seismic Design of Fire Protection Facilities (소방시설의 내진설계를 위한 등재해도 스펙트럼)

  • Kim, Jun-Kyoung;Jeong, Keesin
    • Fire Science and Engineering
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    • v.31 no.1
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    • pp.26-35
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    • 2017
  • Since the Northridge earthquake (1994) and Kobe earthquake (1995), the concept of performance-based design has been actively introduced to design major structures and buildings. Recently, the seismic design code was established for fire protection facilities. Therefore, the important fire protection facilities should be designed and constructed according to the seismic design code. Accordingly, uniform hazard spectra (UHS), with annual exceedance probabilities, corresponding to the performance level, such as operational, immediate occupancy, life safety, and collapse prevention, are required for performance-based design. Using the method of probabilistic seismic hazard analysis (PSHA), the uniform hazard spectra for 5 major cities in Korea with a recurrence period of 500, 1,000, and 2,500 years corresponding to frequencies of (0.5, 1.0, 2.0, 5.0, 10.0)Hz and PGA, were analyzed. The expert panel was comprised of 10 members in seismology and tectonics. The ground motion prediction equations and several seismo tectonic models suggested by 10 expert panel members in seismology and tectonics were used as the input data for uniform hazard spectrum analysis. According to sensitivity analysis, the parameter of spectral ground motion prediction equations has a greater impact on the seismic hazard than seismotectonic models. The resulting uniform hazard spectra showed maximum values of the seismic hazard at a frequency of 10Hz and also showed the shape characteristics, which are similar to previous studies and related technical guides for nuclear facilities.

Interdependence of Corporate Control Mechanisms and Firm Performance in Korea (기업지배구조의 상호관계 및 기업성과에 관한 연구)

  • Cho, Sungbin
    • KDI Journal of Economic Policy
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    • v.28 no.2
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    • pp.131-177
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    • 2006
  • This paper examines a simultaneous determination of corporate control mechanisms, and its effects on firm performance. The corporate control mechanisms considered include the following; insider shareholding, institutional shareholding, the board of directors, dividend policy, and capital structure. This paper applies a simultaneous equation methodology and investigates the interdependence among the corporate control mechanisms. In the first part, the paper finds that firm-level variations of control mechanisms are large across time although average variations are relatively small. These variations are related to one another, which is confirmed by Granger causality test based on dynamic panel autoregression model. More specifically insider shareholding, institutional shareholding and outside director ratio cause each other. With regard to interdependence among the control mechanisms, 2SLS(two stage least squares) regression results show that insider shareholding and institutional shareholding are substitutes while institutional shareholding acts as complements to the ratio of outside members in the board of directors. Then in the second part, the paper examines the relationship between firm performance and corporate governance. Firm performance, measured by Tobin's Q, has a positive association with leverage ratio while that has a negative relation to outside director ratio. This suggests that there may be a room for reforming corporate governance in Korea. Specifically it is necessary to enhance the independence of the outside directors.

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Experimental Study on Rupturing of Artificial Flaw of Pipes for Life Prediction of Underground High Pressure Gas Pipes (지하매설 고압가스배관의 수명예측을 위한 인위결함 배관의 파열실험)

  • Lee, Kyung-eun;Kim, Jeong Hwan;Ha, Yu-jin;Kil, Seong-Hee;Jo, Young-do;Moon, Jong-Sam
    • Journal of the Korean Institute of Gas
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    • v.22 no.5
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    • pp.62-71
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    • 2018
  • According to own investigation conducted by Korea Gas Safety Corporation Gas Safety Research Institute in 2017, the length of underground pipes in domestic high-pressure gas pipelines is approximately 770km, of which 84% is buried in Ulsan and Yeosu industrial complexes. In particular, 56% of underground pipelines have been in operation for more than 20 years. This suggests urgent management of buried high pressure gas pipelines. PHMSA in US and EGIG in Europe, major causes of accidents in buried gas pipelines are reported as third party damage, external corrosion and loss of pipe wall thickness. Therefore, it is important to evaluate whether the defects affect the remaining life of the pipe when defects occur in the pipe. DNV and ASME have evaluated the residual strength of pipelines through the hydraulic rupture test using pipe specimens with artifact flaws. Once the operating pressure is known through the residual strength of the pipe, the wall thickness at the point at which the pipe ruptures is calculated. If we know the accurate rate of corrosion growth, we can predict the remaining life of pipe. In the study, we carried out experiments with A53 Grade.B and A106 Grade.B, which account for 80% of domestic buried pipes. In order to modify the existing model equation, specimens with a defect depth of 80% to 90% was tested, and a formula expressing the relationship between defect and residual strength was made.

The Effects of Franchise Customers' Acquisition Utility and Exchange Utility on Customer Loyalty and Customer Citizenship Behavior (외식 프랜차이즈 고객의 획득효용과 교환효용이 고객충성도와 고객시민행동에 미치는 영향)

  • Kim, Sang-Duck;Im, Hyang-Mi;Seo, Ki-Hong;Yoon, Ok-Sook;Kim, Jong-Hun
    • The Journal of Industrial Distribution & Business
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    • v.10 no.2
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    • pp.39-49
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    • 2019
  • Purpose - Customer loyalty and citizenship behavior are key success factors of franchise system. They make the management of franchisee more effective and efficient. Prior studies, however, mainly dealt with only acquisition utility of customer, such as perceived product/service quality and brand reputation to explain customer loyalty and citizenship behavior, which explains only on one side. We tried to investigate the effect of exchange utility of customer, such as relationship strength and psychological obligation together with the acquisition utility. In addition, we tried to investigate the relationship between customer loyalty and citizenship behavior in franchise context. Research design, data, and methodology - This study used data collected from the dining franchisee managers of 342 franchisors in South Korea. The franchisors consist of more than ten franchisees, the majority of which participated directly in the transaction with franchisor and have worked for more than six months. To test the hypotheses, the study used structural equation model analysis. Results - H1-1, 1-2, 1-3 predicted that acquisition utility would increase customer loyalty to franchisee. In support of H1-1, 1-2, 1-3, the results indicated that acquisition utilities such as perceived product value, perceived service value, and franchise brand reputation had positive effects on customer loyalty. H2-1, 2-2 predicted that exchange utility would increase customer loyalty to franchisee. In support of H2-2, the result indicated that psychological obligation had positive effects on customer loyalty like other acquisition utilities. However, H2-1 was not supported. Relationship strength had no significant effect on customer loyalty. H3 predicted that customer loyalty would increase customer citizenship behavior. In support of H3, the results indicated that customer loyalty had positive effect on customer citizenship behavior. Overall, the evidences generally supported the hypotheses. Conclusion - The results of the study show that not only acquisition utility but also exchange utility increases customer loyalty to franchisee and also show that customer loyalty increases customer citizenship behavior. Interestingly, however, relationship strength has no significant effect on customer loyalty. These results have two implications. The one is that increasing exchange utility can improve customer loyalty as acquisition utility can. The other one is that both of customer utilities can improve customer citizenship via customer loyalty.

The Effect of Perceived Organizational Support on Subjective Career Success: The Mediating Effect of Career Planning (조직지원인식이 주관적 경력성공에 미치는 영향: 경력계획의 매개효과 검증)

  • Kang, Ye-Ji;Lee, Soo-Yeon;Moon, Jin-Hee;Chang, Ji-Hyun
    • Journal of Distribution Science
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    • v.14 no.2
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    • pp.83-92
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    • 2016
  • Purpose - The purpose of this study is to identify the relations among perceived organizational support, career planning, and subjective career success (career satisfaction and job satisfaction). In particular, this study focuses on the mediating effect on the career planning between perceived organization and subjective career success. The target cases are employees of a Korean branch of a global company (A), which operates formal career program to support a career development for employees. Research design, data, and methodology - The data were collected from December, 2014 to March, 2015. 211 out of 300 questionnaires were returned (response rate 70.3%). After the data cleaning, 209 questionnaires were used for the data analysis. These data were analyzed through descriptive statistics, correlation analysis, exploratory factor analysis (EFA), confirmatory factor analysis (CFA), and structural equation modeling (SEM). The whole process of the data analysis was accomplished using the SPSS 21.0 for windows and the AMOS 21 program. Results - The findings of the study are as follows: First, the better the organizational support is perceived, the higher career satisfaction and job satisfaction is. That is, the employees' career and job satisfaction is higher, when they feel themselves received more supporting. Second, perceived organizational support has a positive impact on employees' career planning. This result means that it is important to support employees in their career development. Third, career planning has a positive impact on career satisfaction, but not on job satisfaction. Lastly, it is verified that career planning has a mediating effect between the perceived organizational support and career satisfaction. Not only has the perception of an organizational support a direct impact on career satisfaction, but also an indirect impact through career planning. However, there is not an indirect relationship through career planning, just an direct relationship between the perception of an organizational support and job satisfaction Conclusions - Based on the findings of this study, the major conclusion of the study was as follows: The study provides theoretical values and practical implications for the fact that the differences of the subjective perception about organizational support exist among employees, and the differences have an impact on their career planning as well as subjective career success. Furthermore, some recommendations for workplace were suggested: The companies should support the career development for employees in organization level. Even though employment instability makes individual workers themselves to be responsible for their own career development, it is an important issue in organizational level that employees' career success could have positive effects on organizational development and success, as well. However, there is a limit in the study that analyzing results cannot be generalized due to the data from a single company. Some recommendations for future research are suggested: First, a comparative study should be conducted with other various companies. Second, a hierarchical analyzing model needs to be applied to substantiate how organizational context influences on subjective career success of employees.