• Journal of Biosystems Engineering
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• v.14 no.2
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• pp.67-79
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• 1989

This study was conducted to investigate the applicability of true model theory for pull prediction in a powered lugged wheel-soil system and to examine the possibility of using principles of similitude in investigating the dimensions of soil parameters pertinent to a powered lugged wheel-soil system concerning the pull prediction. The following conclusions were derived from the study; 1) The pull of prototype wheels proved to be predicted by those of the model wheels for the range of the dynamic weight tested. The pull curves of models and prototype were respectively very similar in the shape. From this basic knowledge, it was enabled to apply the similitude theory to the performance prediction of the true model. 2) A conditional equation which can be used for the prediction of pull of prototype by model test was derived as follows. $n_f=n_1^{-b}$ where $n_f$ : force scale = $w/w_m$ $n_1$ : length scale = ${\ell}/{\ell}_m$ b : exponent on the length dimension of the soil property ${\alpha}$ The range of the numerical value of b, which was determined by the least square method, was found to be -2.0~-2.6. 3) Considering a relatively wide variation of b values in the pull prediction, b is considered to be a function of many variales. Thus it was concluded that there are several soil properties which are pertinent to the powered lugged-wheel-soil system concerning the pull prediction, and these soil properties may have the different effects on the pull of model and protytype wheels, to give the different dimension on the soil parameters.

• Journal of Korean Tunnelling and Underground Space Association
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• v.9 no.4
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• pp.343-349
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• 2007

The reduced scale fire test provides basic data but it is not enough to analysis real fire problem directly because there is no exact analogy theory between a real fire and the reduced scale model. Therefore we have developed the large scale calorimeter in order to the real scale fire test. This advanced large scale calorimeter used for physical properties such as a heat release rate, based upon consumption of $O_2$ method. Using this large scale calorimeter, we cameo out the real scale vehicle fire test in order to evaluation for heat release rate. We obtained the calculated result for HRR $2.3{\sim}3.4\;MW$ and this result is very similar to the PIARC candidate HRR. It is approve that this facility has the reliability and it is capable of applying to the advance fire research in the future.

• Journal of Korean Society of Steel Construction
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• v.13 no.2
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• pp.211-221
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• 2001

The dynamic force estimation and strength design of KALES(Korea Accelerated Loading and Environmental Simulator) are studied. The KALES is continuously rotating the test track and subjected to the dynamic or impact forces during operation since the track is composed of straight and curved line. To estimate the dynamic equation for the model car which was already made is derived with analytical and experimental techniques. Using similarity relationships between the model car and KALES, the dynamic force and stability properties for KALES can be predicted. The stress analysis and fatigue life estimation of KALES is also estimated with the calculated dynamic load. From the stress analysis and fatigue life estimation results, it was found that the design of KALES is safe.

• Informatization Policy
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• v.20 no.4
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• pp.23-50
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• 2013

The main purpose of this study is to empirically examine and to develop the optimal model about an influential relationship between the types of source-based trust and knowledge sharing of local government officials. Procedural and distributive justice-based calculative trust in organization, cognition-based trust in organization, cognition-based trust in supervisor, cognition-based trust in coworkers, and emotion-based trust in coworkers were set up as independent variables of this research model, and sharing of tacit knowledge and explicit knowledge based on the knowledge content as dependent variables. The research results shows that the suitability of each model has approximate value to the required level, and that emotion-based trust in coworkers significantly affects knowledge sharing for both the individual and integrated factors in hypothetical influential relationship. This study is expected to help to enable knowledge sharing in various situations by dividing the concepts of trust that affect knowledge sharing into a few types, and deriving the influential model of knowledge sharing by types.

• The Journal of the Acoustical Society of Korea
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• v.39 no.2
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• pp.77-86
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• 2020

In this study, the Eulerian/Lagrangian one-way coupling method is proposed to predict flow noise due to Blade-Tip Vortex Cavitation (BTVC). The proposed method consists of four sequential steps: flow field simulation using Computational Fluid Dynamics (CFD) techniques, reconstruction of wing-tip vortex using vortex model, generation of BTVC using bubble dynamics model and acoustic wave prediction using the acoustic analogy. Because the CFD prediction of tip vortex structure generally suffers from severe under-prediction of its strength along the steamwise direction due to the intrinsic numerical damping of CFD schemes and excessive turbulence intensity, the wing-tip vortex along the freestream direction is regenerated by using the vortex modeling. Then, the bubble dynamics model based on the Rayleigh-Plesset equation was employed to simulate the generation and variation of BTVC. Finally, the flow noise due to BTVC is predicted by modeling each of spherical bubbles as a monople source whose strength is proportional to the rate of time-variation of bubble volume. The validity of the proposed numerical methods is confirmed by comparing the predicted results with the measured data.

• Journal of Digital Convergence
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• v.16 no.4
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• pp.69-77
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• 2018

In this study, we examine the relationship between shared leadership and innovation behaviors of the members, and try to understand what moderate effect trust in these relationships. To do this, we set up research models and hypotheses that shared leadership will influence innovative behavior through literature review. We also added the moderating effect of Trust on the relationship between these variables. For the empirical analysis, a questionnaire survey was conducted for corporate member in Daegu and Kyungbuk area. Multiple regression analysis and hierarchical regression analysis were conducted to test hypotheses. As a result, Shared leadership has a significant effect on innovation behavior. In particular, trust among members has been shown to regulate the relationship between shared leadership and innovation behavior. The results of this study will be applied to the strategic human resources management of major organizations.

• Journal of the Korea Convergence Society
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• v.10 no.12
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• pp.191-197
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• 2019

This study aimed to provide the basic data necessary for lowering the academic and job stress and turnover rate of male dental hygienists in the future, by understanding the academic and job stress factors of male dental hygienists. As the research method, this study conducted the one-to-one interview with five male dental hygienists with career experiences for 1-5 years at dental hospital and dental clinic, and the interview took about an hour. In the results of this study, the main academic stress factors were interpersonal relationship and too much assignment while the main job stress factors were communication problems with female staffs and director, and anxiety about the future. They relieved their stress through meeting with friends, relaxation, and hobbies. Based on such results of this study, it would be necessary to suggest the measures for improving the interpersonal relationship in academic life of male dental hygienists, providing information about employment, and also finding the future-oriented goals and confidence in the profession as a male dental hygienist.

• The Journal of the Korea Contents Association
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• v.8 no.4
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• pp.255-263
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• 2008

The purpose of this treatise is to evaluate impact of education and training of travel industry's employees upon their job satisfaction and to seek for improving efficiency of such education and training and measures for personnel management. It is also to evaluate impact of education and training of travel industry's employees upon their job performance. Moreover it is attempted to make suggestions for emphasizing importance of developing potentiality of travel industry's employees and suggestions for enhancing job satisfaction of employees. Review on outcome of education and training of travel industry's employees revealed that improvement of their job satisfaction depends on contents of education and training and motivation for it, desire and ability for achievement. Also it depends on support from their superiors or colleagues and existence of environmental atmosphere. In future it is necessary to develop diverse education and training programs for the employees and not only travel industry but also competent government agencies should make long-term investment and support for fostering excellent employees in future.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.7 no.3
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• pp.27-37
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• 2012

The purpose of this study is to review the effect of internal marketing on job satisfaction in food service industry. In order to verify and achieve the purposes mentioned above, questionnaire data are gathered and analysed from 438 employees and their superiors for measuring employees' service quality fromKangwon province. Multiple regression is applied to test the proposed 2 hypotheses: the relationship between internal marketing and intrinsic job satisfaction, and the relationship between internal marketing and extrinsic job satisfaction. Empirical survey's findings are as follows; First, management support, internal communication and employment security have positive relationships with intrinsic job satisfaction. Second, management support, training & education has positive effect on extrinsic job satisfaction and employment security have positive relationships with extrinsic job satisfaction.

• Journal of Korean Tunnelling and Underground Space Association
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• v.8 no.1
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• pp.53-63
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• 2006

The objective of this study is to analyze the smoke movement and the smoke extraction efficiency using by the partial extraction system for case of tunnel fire. Based on Froude modeling and isothermal model, the 1/20 scaled model tunnel (12m long) was constructed. In the case of the upper critical velocity in the main tunnel, the smoke extraction efficiency shows almost same between group damper and distributed damper. Finally, if the fire occurs on a traffic Jam in a tunnel, it is proposed that the open dampers in partial gallery extract smoke from the main tunnel without jet fan operation. Then, after the passengers have escaped the tunnel, the jet fans work on. On the other hand, If the traffic is uncongested in the tunnel, the jet fans (smoke control system) and partial extraction system (smoke exhaust system) are operated at once in tunnel fire.