• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.34 no.4
• /
• pp.467-474
• /
• 2010

Stainless steel sheets are widely used as the structural material for railroad cars and commercial vehicles. Structures made of stainless steel sheets are commonly fabricated by gas welding, For the fatigue design of gas welded joints such as fillet joints, it is necessary to obtain design information of the stress distribution at the weldment as well as the fatigue strength of the gas-welded joints. Further, the influence of the geometrical parameters of gas-welded joints on stress distribution and fatigue strength must be evaluated. in this study, ${\Delta}P-N_f$ curves were obtained by fatigue tests. and, the ${\Delta}P-N_f$ curves were rearranged on the basis of the ${\Delta}{\sigma}-N_f$ relation for the hot-spot stresses at the gas-welded joints. These results, were used for conducting an accelerated life test(ALT) From the experiment results, an acceleration model was derived and factors were estimated. The objective is to obtain the information required for the analysis of the fatigue lifetime of fillet welded joints and for data analysis by the statistic reliability method to save time and cost and to develop optimum accelerated life prediction plans.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.9 no.2
• /
• pp.205-217
• /
• 2007

The behavior characteristics of underground structures are reported as they are not affected by their dynamic characteristics such as surface structures, but by dynamic characteristics of soil and rock surrounding the underground structures. Therefore, dynamic behavior of surrounding soil and rock dominates the dynamic behavior of the underground structure. The purpose of this paper is to analyze the dynamic response (longitudinal deformation and ovaling deformation) of the underground structure under earthquake loading. The dynamic responses of the underground structures were evaluated with varying earthquake conditions, soil conditions, and structural conditions using conventional closed-form solution of seismic behavior of underground structure. In addition, shaking table tests were conducted to simulate the earthquake loading and the dynamic behavior of the model was analyzed.

• Journal of Distribution Science
• /
• v.16 no.1
• /
• pp.37-46
• /
• 2018

Purpose - This study is to investigate the effects of consumption motives of restaurant customers on the perception of the importance of restaurant attributes, and to determine the influence of the consumption motives on the empirical and functional attributes between Vietnam and Korea. Research design, data, and methodology - Questionnaire items from previous studies were revised to fit the research purpose of the present study. From August 1 to August 25, 2017, questionnaires were simultaneously administered in Korea and Vietnam using both on-line and off-line survey methods (including SNS and e-mail). With 381 surveyed questionnaires in Vietnam(219) and Korea(162), this study was conducted by using SPSS 22.0 to verify the reliability and validity of the measured variables. Structural equation model (SEM) was employed as a statistical method for the hypotheses test of this study. Results - The results showed that hedonic eating-out motive has more influence on the importance of empirical attribute than that of functional attribute in restaurant. In addition, utilitarian eating-out motive has more influence on functional attributes than empirical attributes. However, these relationships showed the difference between countries in Vietnam and Korea. As for in Korea, consumers' hedonic and utilitarian motives of eating-out were more influential on experimental and functional attributes. Conclusions - This study analyzed the influence on the importance of the eating-out motives of restaurant attributes and how this differed between Vietnamese and Korean.

• Journal of Information Technology Services
• /
• v.9 no.1
• /
• pp.27-42
• /
• 2010

Recently, many organizations are actively adopting Enterprise Architecture (EA) as a methodology to manage IT assets and build IT-based business system. However, most existing studies on EA have focused on the adoption stage of EA. Now the research concerning effective management and utilization of EA after adopting EA is keenly required. This study intended to empirically examine how the role of EA operating unit and the EA utilization capability of organizational members impact on EA performance at the post-adoption stage of EA. Based on Resource Based View (RBV), this study proposed the model and the hypotheses describing that the impact of the role of EA operating unit on EA performance is mediated by the EA utilization capability of organizational members. In order to test the hypotheses, the field survey whose respondents were seventy four Korean public agencies which have adopted EA was conducted by means of questionnaire. Data analysis was done with partial least square (PLS), which is a structural equation modeling (SEM) technique that uses a component-based approach to estimation. The results of the empirical analyses showed that the organizational operation ability of EA operating unit significantly influenced EA performance via the EA utilization capability of organizational members, but that EA education and training performed by EA operating unit did not. The results of this study provided a lot of theoretical and practical implications regarding EA management activities at the post-adoption stage of EA to enhance EA performance.

• Journal of Distribution Research
• /
• v.9 no.2
• /
• pp.75-99
• /
• 2004

The primary purpose of this research is to develop and test a model that explains the process of how trust in a supplier firm and salesperson through relational commitment influence buyer's positive and desirable behavior. In order to do so, we are empirically to examine how a supplier firm and salesperson trust can reinforce buyer's relational commitment leading to relational citizenship behavior using over 138 buying firms, Through structural equation modeling, we find that trust in a supplier firm and salesperson influence the relational commitment and relational commitment enhance relational citizenship behavior. However, trust in a supplier firm is unrelated to the buying firm's relational citizenship behavior whereas trust in salesperson has direct effect on relational citizenship behavior. Finally, we discuss several theoretical and practical implications, and suggest limitations for the research and future research issue.

• Tribology and Lubricants
• /
• v.32 no.4
• /
• pp.113-118
• /
• 2016

As an economic, high quality, and highly reliable gear with low noise and low vibration is demanded, an overall finite element analysis regarding a gear is required. Also, an infrared thermography test, which is a quantitative testing technique, is demanded for safety and longer lifespan of gear products. In order to manufacture a gear product or to determine safety of a gear being used, it is necessary to precisely determine ingredients of a material constituting a gear and detect any internal defect. This study aims to realize a design that minimizes the spur gear displacement with respect to power during its rotation and ensures the spur gear control capacity by using a 3D model and the midasNFX program. This facilitates the assessment of the possibility of cracking by evaluating the stress intensity and focusing on the integrity of the spur gear. We prepare the specimen of the spur gear based on the possibility of cranking as per the result of the structural interpretation from an infrared ray thermal measuring technique. After cooling the spur gear, we perform experiments using thermography and halogen lamps and analyze the temperature data according to the results of the experiment. In the experiment which we use thermography after cooling, we find a rise in the temperature of the room. As a result, the defective part show temperatures lower than their surroundings while the normal parts have temperatures higher than the defective parts. Therefore, it possible to precisely identify defective part owing to its low temperature.

• Korean Journal of Health Education and Promotion
• /
• v.25 no.2
• /
• pp.61-72
• /
• 2008

Objectives: This study was conducted to examine the relationships among body image, self-esteem and sociability according to perception of body shape and obesity level. Methods: The subjects in this study were 325 elementary school youngsters in their sixth year. A survey was conducted, and one-way ANOVA, Scheffe test, Pearson's correlation analysis and path analysis were used for data analysis. Results: Normal weight group accounted for 43.4%, under weight group 34.8% and obesity group 21.8%. In underweight group, 53.1% of the subjects perceived their body was normal or fatty while 17% of subjects in normal group perceived their body was fatty. There were significant differences in body image according to the perception of body shape by grade(F=15.90, p=.000) and to the level of obesity(F=6.18, p=.002). There was a significant difference in self-esteem according to the perception of body shape by grade(F=3.17, p=.430). There was a significant difference in sociability according to the level of obesity(F=3.48, p=.032). There was significantly strong positive correlation among their body image, self-esteem and sociability. A structural equation model was tested and fitted the data well. Conclusions: This study suggested that health education is needed to establish the correct body image from the elementary school periods by school health educators. The right body image is more important than anything else to improve self-esteem and sociability.

• Structural Engineering and Mechanics
• /
• v.66 no.2
• /
• pp.273-283
• /
• 2018

Currently, the dynamic amplification effect of suction is described using the wind vibration coefficient (WVC) of external loads. In other words, it is proposed that the fluctuating characteristics of suction are equivalent to external loads. This is, however, not generally valid. Meanwhile, the effects of the ventilation rate of louver on suction and its WV are considered. To systematically analyze the effects of the ventilation rate of louver on the multi-dimensional WVC of ultra-large cooling towers under suctions, the 210 m ultra-large cooling tower under construction was studied. First, simultaneous rigid pressure measurement wind tunnel tests were executed to obtain the time history of fluctuating wind loads on the external surface and the internal surface of the cooling tower at different ventilation rates (0%, 15%, 30%, and 100%). Based on that, the average values and distributions of fluctuating wind pressures on external and internal surfaces were obtained and compared with each other; a tower/pillar/circular foundation integrated simulation model was developed using the finite element method and complete transient time domain dynamics of external loads and four different suctions of this cooling tower were calculated. Moreover, 1D, 2D, and 3D distributions of WVCs under external loads and suctions at different ventilation rates were obtained and compared with each other. The WVCs of the cooling tower corresponding to four typical response targets (i.e., radial displacement, meridional force, Von Mises stress, and circumferential bending moment) were discussed. Value determination and 2D evaluation of the WVCs of external loads and suctions of this large cooling tower at different ventilation rates were proposed. This study provides references to precise prediction and value determination of WVC of ultra-large cooling towers.

• Journal of Korea Port Economic Association
• /
• v.27 no.3
• /
• pp.13-39
• /
• 2011

Many previous studies on the subject of supply chain have consistently claimed that they need collaboration among the partners of supply chains in order to enhance supply chain performance. The purpose of research is to examine the causal linkages among relational characteristics, collaboration, performance in the logistics firm and this research focuses on two types collaboration(operational collaboration and strategic collaboration) as the mediation variable between relational characteristics and supply chain performance. To test the above research questions, we collected data from logistics firm(N=164). The proposed structural model was tested using the PLS(Partial Least Square) statistical program. The research results are as follows. Trust, and information sharing have positive influences on operational collaboration, and operational collaboration have also positive influences on supply chain performance. Duration and information sharing have positive influences on strategic collaboration. However, strategic collaboration has non-positive influences on supply chain performance. The effect of relational characteristics on supply chain performance is mediated by operational collaboration.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.35 no.3
• /
• pp.87-94
• /
• 2012

This study investigates the relationship among locus of control, organizational justice, and job satisfaction. First, this study examines the conceptual structures of organizational justice through field study. Second, organizational justice influences job satisfaction. Third, locus of control influences organizational justice. Literature review identified four factors of organizational justice - distributive, procedural, interpersonal, and informational justice. These identified determinants are expected to have significant relationships with locus of control and job satisfaction. Questionnaires were distributed to 500 members of a manufacturing companies. Among returned questionnaires, 357 samples were used for empirical study. Structural equation analyses based on PLS (partial least square) method were employed to test the hypotheses and the model. The overall adequacy of fit was found to be acceptable. Confirmatory factor analyses supported a 4-factor structure of organizational justice. Distributive, procedural, interpersonal, and informational justice had significant positive effects on job satisfaction. In addition, the effects of locus of control had significant positive effects on organizational justice factors. The results of this study suggest that interpersonal and informational justice should be regarded as important factors of organizational justice to analyze the relationships between locus of control and job satisfaction as well as the relationships among the justice constructs.