• Smart Structures and Systems
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• v.26 no.2
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• pp.185-193
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• 2020

Nonlinear vibration of sandwich plate with functionally graded material (FGM) core and carbon nano tubes reinforced (CNTs) nano-composite layers by considering temperature-dependent material properties are studied in this paper. Base on Classical plate theory (CPT), the governing partial differential equations of motion for sandwich plate are derived using Hamilton principle. The Galerkin procedure and multiple scales perturbation method are used to find relation between nonlinear frequency and amplitude of vibration response. The dynamic responses of the sandwich plate are also investigated in both time and frequency domains. Then, the effects of nonlinearity, excitation, power law index of FG core, volume fraction of carbon nanotube, the function of material variations of FG core, temperature changes, scale transformation parameter and damping factor on the frequency responses are investigated.

• Asia pacific journal of information systems
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• v.26 no.4
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• pp.509-525
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• 2016

According to the dynamic changes in the business environment, the structural transformation of firms has had an observable trend. An increasingly large number of firms have been transforming into either project-based organizations or project expert groups. This study aims to investigate the antecedents required for the optimal level of empowerment with consideration of the project-based team environmental nature and job characteristic. Three factors are applied to measure the significant effects on psychological empowerment as the result variables. To determine the antecedents and consequent factors of psychological empowerment, employees' interviews and precedent studies are used. For the empirical study, four determinants of empowerment variables are modeled into a second-order reflective construct. This study finds that psychological empowerment significantly affects performance. Therefore, this study can serve as a guideline for development and operating methods for project success.

• Journal of Mechanical Science and Technology
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• v.19 no.spc1
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• pp.237-254
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• 2005

The vast mechanical systems could be classified as closed loop system, open loop system and open & closed (switching) system. In the closed loop system, the kinematics and dynamics of 3-D mechanisms will be reviewed and closed form solutions using the direction cosine matrix method and reflection transformation method will be introduced. In the open loop system, kinematic & dynamic analysis methods regarding the redundant system which has more degrees of freedom in joint space than those of task space are reviewed and discussed. Finally, switching system which changes its phase between closed and open loop motion is investigated with the principle of dynamical balance. Among switching systems, the human gait in biomechanics and humanoid in robotics are presented.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.280-285
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• 2000

A viscoelastic constitutive equation of rubber that is under small oscillatory load superimposed on large static deformation is proposed. The proposed model is derived through linearization of Simo's viscoelastic constitutive model and reference configuration transformation. The proposed constitutive equation is extended to a generalized viscoelastic constitutive equation that includes widely used Mormin's model as a special case using objective stress increment. Static deformation correction factor is introduced to consider the influence of Pre-strain on the relaxation function. The proposed constitutive model is tested fer dynamic behavior of rubber specimens with different carbon black contents. It is concluded from the test that the viscoelastic constitutive equation for filled rubber must include the influence of the static deformation on the time effects. The suggested constitutive equation with static deformation correction factor shows good agreement with test values.

• Journal of Korea Multimedia Society
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• v.18 no.3
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• pp.419-428
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• 2015

Stone is a hybrid genre movie in which two different film genres coexist; one is a gangster movie, the other Baduk movie. This film deals with a relationship between an old gangster boss and a young Baduk player. The coexistence of two different worlds becomes a reason for a unique ambiance of this film, because Stone is dynamic and brutal as much as static and meditative. Firstly, this article aims to analyze the narrative structure and characters of this film comparing with conventions of gangster movie genre, especially 'jopok film' of Korean cinema. Secondly, we examine characters of this film and their relationship. Since the economic crisis under the IMF structure, a great part of korean gangster movie has represented the weakness of the fatherhood and the disorganization of family. However, in Stone, the friendship between two heroes, Namhae and Minsu, turns to a father-son relationship. In this way, Stone transformed conventions of film genre.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.315-319
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• 2003

This paper presents modeling and analysis of static and dynamic characteristics in PWM Boost AC-AC converter used for input voltage sag compensation of custom power. Especially, using circuit DQ transformation technique, an equivalent circuit in fundamental frequency domain is obtained which has all the system characteristics. Moreover, voltage gain and input power factor is analytically induced and linearized state equation at the specific operating point is given. Finally, simulation results show the validity of the proposed modelling and analyses.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1413-1415
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• 2002

The Displacement current measurement system used in this experiment because detecting the dynamic behavior of monolayers at the air-water interface is possible. It basically consists of a film balance, a pair of electrodes connected to each other through a sensitive ammeter. Here, one electrode is suspended in air and the other electrode is placed in the water. PBLG phase transformation measured by Maxwell-displacement-current-measurement method in surface of the water. Measured (surfacc pressure, displacement current and dipole moment) of monolayers of PBLG on the water surface. We measured displacement current that occur when changed temperature(15, 20, 25$^{\circ}$ ) and the compression speed(30, 40, 50(mm/min)). From the result, it is known that curren generated in the range of high surface pressur compression velocity and temperature become faste.

• Management Science and Financial Engineering
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• v.9 no.2
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• pp.21-45
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• 2003

Various organizational factors effect successful implementation of IT enabled business transformation. Among them, the most critical success factor is deemed to overcoming change management problem. Lots of studies have been made on implementation methodologies and business process formalizations to encourage organizational members to accept new business process changes. However, the logic of process redesign still depends on qualitative problem solving techniques mostly depending on basically human intuition such as brainstorming, cause-and-effect analysis, and so on. In this paper, we develop algorithmic procedure applicable to designing various business process changes such as process automation, business process resequencing, and more radical process integration. The framework is employed from dynamic programming approach in the literature, which is based on the decision making paradigm of organizations to abstract business processes as quantitative decision models. As such, our research can fill the gap of limited development of theory based analytic methodologies for business process design, by providing objective rationale to reach the consensus among the organizational members including senior management.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.395-400
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• 2003

Power steering oil pump is generally used to support the power to steering system of most kinds of vehicle. The noise caused by power steering ell pump make passenger to be uncomfortable, because its frequency is higher than that is produced by engine. In this paper, the field test of real car was carried out to analyze the phenomenon of the pump noise, and the lab test was also performed to survey the dynamic characteristics of pump assembly. The results of the series of tests show that frequency range of 600-800㎐ should be dealt with to reduce the pump noise. After four cases of design changes were carried out to actually reduce the noise and tested in condition of partial assembly. Some improvement can be gotten from a certain design change.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.10
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• pp.983-989
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• 2004

In this paper, a modeling method for the vibration analysis of rotating structures employing multi-reference frames is presented. The geometric stiffening effect that results from centrifugal inertia force is considered. In most previous studies single reference frame has been employed for the analysis. In the present study, a modeling method employing multi-reference frames is presented, and the effects of employing multi-reference frames on the analysis accuracy are investigated through solving numerical examples.