• Journal of KSNVE
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• v.8 no.1
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• pp.87-98
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• 1998

A Precise actuator in the pick-up of a DVDR/P(Digital Video Disk Recorder/Player) is required to control position accurately. Therefore, in order to develop a reliable actuator, dynamic characteristics of each part in an actuator should be examined closely. This paper presents systematic design process of an actuator using various analysis methods to confirm fundamental capability and solve performance problems related to dynamic characteristics of an actuator beforehand. Particularly, sensitivity analysis is presented through the program using mass moment of inertia and general equations of rigid body. Through the result of sensitivity analysis, important inferiority causes of actuator are selected and reduced. In the end, dynamic characteristics of manufactured actuators are improved considerably.

• Earthquakes and Structures
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• v.17 no.1
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• pp.39-48
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• 2019

This paper presents an experimental study on a 1/2 scale steel frame with archaized-style under the pseudo-dynamic loading. Four seismic waves, including El Centro wave, Taft wave, Lanzhou wave and Wenchuan wave, were input during the test. The hysteresis characteristic, energy dissipation acceleration response, displacement response, strength, stiffness and strain were analyzed. Based on the experiment, the elastoplastic dynamic time-history analysis was carried out with the software ABAQUS. The stress distribution and failure mode were obtained. The results indicate that the steel frame with archaized-style was in elastic stage when the peak acceleration of input wave was no more than 400 gal. Under Wenchuan wave with peak acceleration of 620 gal, the steel frame enters into the elastoplastic stage, the maximum inter-story drift was 1/203 and the bearing capacity still tended to increase. During the loading process, Dou-Gong yielded first and played the role of the first seismic fortification line, and then beam ends and column bottom ends yielded in turn. The steel frame with archaized-style has good seismic performance and meets the seismic design requirement of Chinese code.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.3
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• pp.339-346
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• 2012

The pre-evaluation of the current-collection performance is an important issue for high-speed railway vehicles. In this paper, using flexible multibody dynamic analysis techniques, a simulation model of the dynamic interaction between the catenary and pantograph is developed. In the analysis model, the pantograph is modeled as a rigid body, and the catenary wire is developed using the absolute nodal coordinate formulation, which can analyze large deformable parts effectively. Moreover, for the representation of the dynamic interaction between these parts, their relative motions are constrained by a sliding joint. Using this analysis model, the contact force and loss of contact can be calculated for a given vehicle speed. The results are evaluated by EN 50318, which is the international standard with regard to analysis model validation. This analysis model may contribute to the evaluation of high-speed railway vehicles that are under development.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.4
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• pp.121-130
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• 2001

For the purpose of optimal control of anti-lock brake systems, precise dynamic characteristics analysis of hydraulic modulator, especially solenoid valve is necessary. However, most of researches so far have dealt with dynamic characteristic analysis of valve itself, and the results have been restrictively applied to the actual ABS modulator, where hydraulic pressure is acting. In this study, mathmatical modeling and experimental analysis were peformed in order to evaluate the valve dynamic characteristics when the hydraulic pressure is applied. High pressure on the master cylinder that affects on the valve dynamic characteristics have been analyzed quantitatively, and performance improvement methods have been suggested through parameter study. Consequently, results of solenoid valve dynamic characteristics analysis derived in the study can be utilized as criteria for the optimal control of anti-lock brake systems.

• Journal of Digital Convergence
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• v.15 no.1
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• pp.163-170
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• 2017

The purposes of this study is to examine the effect of fitness among entrepreneurship, dynamic capabilities and innovation activities on business performance. A survey was conducted and analyzed on small & medium manufacturing companies in Korea with the following result of the study. First, the fitness of entrepreneurship and dynamic capabilities, the fitness of dynamic capabilities and innovation activities, the fitness of entrepreneurship and innovation activities have a significant effect on business performance respectively. Second, the fitness of all the three variables also has a significant positive effect on the performance. Additional path analysis shows that dynamic capabilities and innovation activities have mediating roles between entrepreneurship and business performance. The results imply that not only each of the entrepreneurship, dynamic capabilities, and innovation activities has a positive effect on business performance but also the three factors in harmony have a synergic positive effect on the business performance.

• Structural Engineering and Mechanics
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• v.3 no.4
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• pp.391-410
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• 1995

The application of adaptive finite element method to dynamic problems is investigated. Both the kinetic and strain energy errors induced by space and time discretization were estimated in a consistent manner and controlled by the simultaneous use of the adaptive mesh generation and the automatic time stepping. Also an optimal ratio of spatial discretization error to temporal discretization error was discussed. In this study it was found that the best performance can be obtained when the specified spatial and temporal discretization errors have the same value. Numerical examples are carried out to verify the performance of the procedure.

• Journal of Magnetics
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• v.14 no.4
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• pp.175-180
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• 2009

This paper describes the design and analysis of a tubular linear actuator for intelligent AAP (Active Accelerate Pedal) system. In a driving emergency, the electromagnetic actuator produces an additional pedal force such as the active pedal force and vibration force to release the driver's foot on accelerator pedal. A prior study found that the linear actuator with a ferromagnetic core had a problem in transferring the additional force naturally to a driver due to the cogging force. To reduce the cogging force and obtain higher performance of the AAP system, a coreless tubular linear actuator is suggested. Electromagnetic finite element analysis is executed to analyze and design the coreless tubular actuator, and dynamic analysis is performed to characterize the dynamic performance of the AAP system with the suggested tubular actuator for two types of thrust force.

• Journal of Distribution Science
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• v.20 no.7
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• pp.11-22
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• 2022

Purpose: Since the emergence of the Covid-19 pandemic, almost all the hospitality industry has experienced a decrease in the distribution of room occupancy. Therefore, this study aims to examine how to improve the performance of 5-star hotels in Bali by involving market orientation, revenue management orientation, competitive advantage, dynamic capability, and pricing capability. Research design, data and methodology: This study involved 127 managers in 62 five-star hotels in Bali. Analysis of this study using structural equation modelling (SEM) with SmartPLS software. Results: This study reveals that the performance of five-star hotels in Bali is influenced by factors such as market orientation, revenue management orientation, competitive advantage, dynamic capability, and pricing capability. In addition, revenue management orientation, competitive advantage, and dynamic capability have been shown to mediate the effect of market orientation on the performance of five-star hotels in Bali. Finally, pricing capability has been proven to have not been able to increase the revenue and performance of five-star hotels in Bali. Conclusions: Hotel performance is largely determined by several important factors which include market orientation, revenue management orientation, competitive advantage, dynamic capability, and pricing capability. This study provides important implications for hospitality practitioners to improve the distribution of hotel performance.

• Structural Engineering and Mechanics
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• v.17 no.3_4
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• pp.281-290
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• 2004

A review of current procedures being used in engineering practice to analyze the response of structure/foundation systems subjected separately to different types of dynamic excitation, such as earthquake, sea-wave action, wind, or moving wheel loads, is presented. Separate formulations are given for analyzing systems in the time and frequency domains. Both deterministic and stochastic forms of excitation are treated. A distinction is made between demand and capacity analyses.

• Structural Engineering and Mechanics
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• v.25 no.2
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• pp.201-217
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• 2007

A harmonic type differential quadrature approach for nonlinear dynamic analysis of multi-degree-of-freedom systems has been developed. A series of numerical examples is conducted to assess the performance of the HDQ method in linear and nonlinear dynamic analysis problems. Results are compared with the existing solutions available from other analytical and numerical methods. In all cases, the results obtained are quite accurate.