• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.597-602
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• 2006

In this paper, a proper support tuning method is established by identifying the dynamic characteristics of the machine, the floor. and the inertia force. Also, the limitation of a passive isolation is presented. To simplify the dynamic analysis and to establish a proper design method for supporting system, each of the machine and the floor is modeled as a single degree of freedom spring-mass-damper system under careful investigation of the dynamic characteristics of each system and appropriate assumptions. Then, the dynamic behavior of a 2DOF system and the effect of the mass and the damping are investigated. Also, the characteristics of motion profiles are investigated. In addition, a quasi-static analysis on the transmitted force through support is performed and related tests are performed.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.1299-1306
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• 2005

The introduction of geodetic methods of absolute displacement monitoring in tunnels has improved the value of the measurements significantly. By using this method, structurally controlled behavior and influences of an anisotropic rock mass can be determined and the excavation and support adjusted accordingly. In this study cases of tunnel monitoring in anisotropic/heterogeneous rock masses are analyzed, and various anisotrpic behavior of tunnel can be estimated. Because rock anisotropy and heterogeneity can have great influence on tunnel behavior, tunnel design considering rock anisotropy and heterogeneity is needed. Also under construction, feedback must be performed by using face mapping and monitoring to prevent over-deformation and tunnel collapse.

• Structural Engineering and Mechanics
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• v.5 no.5
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• pp.507-521
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• 1997

The ultimate behavior of a reinforced concrete hyperbolic paraboloid saddle shell under uniformly distributed vertical load is investigated using an inelastic, large displacement finite-element program originally developed at North Carolina State University. Unlike with the author's previous study which shows that the saddle shell possesses a tremendous capacity to redistribute the stresses, introducing tension stiffening in the model the cracks developed are no longer through cracks and formed as primarily bending cracks. Even though with small tension stiffening effect, the behavior of the shell is changed markedly from the one without tension stiffening effect. The load-deflection curves are straight and the slope of the curves is quite steep and remains unchanged with varying the tension stiffening parameters. The failure of the shell took place quite suddenly in a cantilever mode initiated by a formation of yield lines in a direction parallel to the support-to-support diagonal. The higher the tension stiffening parameters the higher is the ultimate load. The present study shows that the ultimate behavior of the shell primarily depends on the concrete tensile characteristics, such as tensile strength (before cracking) and the effective tension stiffening (after cracking). As the concrete characteristics would vary over the life of the shell, a degree of uncertainty is involved in deciding a specified ultimate strength of the saddle shell studied. By the present study, however, the overload factors based on ACI 318-95 are larger than unity for all the cases studied except that the tension stiffening parameter is weak by 3 with and without the large displacement effect, which shows that the Lin-Scordelis saddle shell studied here is at least safe.

• The Journal of the Korea Contents Association
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• v.20 no.4
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• pp.686-701
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• 2020

The purpose of this study is to find out how employee's gratitude disposition affects Organizational Citizenship Behavior(OCB) and empirically validating multiple mediation effect of perceived organizational support(POS) and job satisfaction. For this study, an online survey has been conducted on office workers to analyze 380 sets of answers, reviewed reliability and validity through CFA and used SPSS 25.0, AMOS 25.0, Macro Process 3.0, a bootstrap method to test hypothesis. As a result, it is verified that an employee's gratitude disposition positively affects OCB, POS and job satisfaction and that there exists a multiple mediation effect of POS and job satisfaction. In this study, it is validated that an employee's gratitude disposition has a positive influence on OCB and an employee's gratitude disposition, an individual trait, is a related antecedent variable of POS. The result of this study is meaningful that it suggests boosting gratitude disposition, a positive psychological factor, in an organization can positively affect employees' job attitude and organization effectiveness.

• Journal of the Korean Home Economics Association
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• v.44 no.1 s.215
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• pp.59-74
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• 2006

As an exploratory inquiry prior to developing a measure to assess Korean families with adolescents' family resilience, this study examined the construct validity of the family resilience measures that were developed in the U. S. Iowa Youth and Families Project(Conger & Elder, 1994): emotional support between spouses, problem solving style between spouses, and parenting behavior. The participants were 277 pairs of middle aged, middle class husbands and wives (554 individuals) who were the parents of first graders in middle schools in the metropolitan areas around Seoul. The results of exploratory and confirmatory factor analysis supported the construct validity, indicating that emotional support, problem solving style, and parenting behavior may be used as measures to assess Korean family resilience. However, further tests of convergent validity using various assessment methods and analytical procedures are needed to ensure the construct validity of family resilience measures.

• 대한예방의학회:학술대회논문집
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• 2002.10a
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• pp.390-391
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• 2002

• Proceedings of the Korean Geotechical Society Conference
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• 2005.10a
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• pp.49-83
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• 2005

ESCP Project showed an urban excavation case and introduced design method for case of Soil-Structure behavior in urban excavation. In this case, a retaining structures design to analysis the behavior of retaining wall and adjacent structures in urban excavations was applied by using a Elasto-plastic beam and limit Equilibrium analysis and soil-structure interaction analysis. Reliable design of earth retaining structures and the ground adjacent to braced wall in urban excavation are often difficult due to many variable factors. The ground settlement and the damage of adjacent structures in urban excavation has been an imprtant issue. Therefore, the stability of the adjacent structures must be secured with the excavation support and research on the protection of adjacent structure is necessary.

• Journal of the Korean Data and Information Science Society
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• v.14 no.4
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• pp.845-852
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• 2003

Forecasting exchange rate movements is a challenging task since exchange rates impact world economy and determine value of international investments. In particular, Korean-U.S. exchange rate behavior is very important because of strong Korean and U.S. trading relationship. Neural networks models have been used for short-term prediction of exchange rate movements. Least squares support vector machine (LS-SVM) is used widely in real-world regression tasks. This paper describes the use of LS-SVM for short-term and long-term prediction of Korean-U.S. exchange rate.

• Journal of the Korean Institute of Intelligent Systems
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• v.18 no.5
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• pp.712-717
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• 2008

In swarm robot systems, each robot must act by itself according to the its states and environments, and if necessary, must cooperate with other robots in order to carry out a given task. Therefore it is essential that each robot has both learning and evolution ability to adapt the dynamic environments. In this paper, reinforcement learning method with SVM based on structural risk minimization and distributed genetic algorithms is proposed for behavior learning and evolution of collective autonomous mobile robots. By distributed genetic algorithm exchanging the chromosome acquired under different environments by communication each robot can improve its behavior ability. Specially, in order to improve the performance of evolution, selective crossover using the characteristic of reinforcement learning that basis of SVM is adopted in this paper.

• Journal of Distribution Science
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• v.17 no.8
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• pp.57-66
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• 2019

Purpose - The purpose of this study is to elucidate the perception differences between CEOs and employees, and to derive a plan for improving performance by using theory of planned behavior (TPB) to enhance the competitiveness of SMEs exposed to various difficulties until recently. Research design, data and methodology - A total of 238 valid questionnaires were collected for CEOs and members of SMEs. In order to clarify the difference of perception, independent sample t-test and multi-group analysis using AMOS were conducted. Simple regression analysis and structural equation were used to confirm whether the theory of planned behavior was applied at the level of SME. Results - The CEO group is more aware of company's ethical responsibility activities and organizational support than the group of employees, and collectivism contributes more to organizational development than individualism tendency. Also, the theory of planned behavior is applied to the SME level as well. Conclusion - This study suggest that CEOs need to accept the pluralism of their members for the development of SMEs. In addition, it is necessary to form a consensus on ethical responsibility activities that corporations are performing by supporting diverse strategies and members' participation in management decision-making.