• Proceedings of the KSME Conference
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• 2008.11a
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• pp.865-869
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• 2008

Juryeonggu is a Cuboctahedral die that had used in ancient Korea. This Cuboctahedral is consisted of different two penal servitudes of 14 facepieces, but the probability distribution can appear equally so it can be usable as a die. In this paper, achieved research study about probability of a Cuboctahedral die that have quadrilateral and triangle preferentially to search Juryeonggu's probability calculation method. First, confirmed probability distribution through Multibody-dynamics analysis and verified probability distribution through several experiments. Finally, with this simulation data, achieved theoretical analysis about Cuboctahedral die occurrence probability by using the residual momentum energy.

• International Journal of Precision Engineering and Manufacturing
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• v.5 no.4
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• pp.43-49
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• 2004

A spring-actuated linkage system is used to satisfy the desired opening and closing characteristics of the electric contacts of a vacuum circuit breaker. If the type of a circuit breaker and the structure of the linkage system are predetermined, then design parameters such as stiffness, free length and attachment points of the spring become the important issues. In this paper, based on the energy conservation, the total system energy is constant throughout the operating range of the mechanism; a systematic procedure to optimize the spring design parameters is developed and applied to a simplified mechanism of a circuit breaker. The developed procedure is converted to the environment of the multi-body dynamics program, ADAMS for an in-depth consideration of the complex dynamics of a circuit breaker mechanism.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.1093-1098
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• 2002

Dynamic behaviors of the Korean High-speed Train(KHST) have been analyzed to investigate the performance on the stability, the safety and the ride comfort. Multi-body dynamics analysis program using Recursive method, called RecurDyn, have been employed in the numerical simulation. To model the wheel-rail contact, the RecurDyn uses its built-in module which uses the square root creep law. The accuracy of the rail module in RecurDyn. however, decreases in the analysis of flange contact because it linearizes the shape of the wheel and rail. To solve this problem, a nonlinear contact theory have been developed that considers the profiles of the wheel and rail. The results show that the KHST still needs more stability. The problem should be solved by the examinations of module and modeling.

• Journal of Information Technology Applications and Management
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• v.24 no.2
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• pp.81-96
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• 2017

Forecasting long-term mobile service demand is inevitable to establish an effective frequency management policy despite the lack of reliability of forecast results. The statistical forecasting method has limitations in analyzing how the forecasting result changes when the scenario for various drivers such as consumer usage pattern or market structure for mobile communication service is changed. In this study, we propose a dynamic model of the mobile communication service market using system dynamics technique and forecast the future demand for long-term mobile communication subscriber based on the dynamic model, and also experiment on the change pattern of subscriber demand under various scenarios.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.711-712
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• 2010

In the present work, the dynamic characteristics of variable nozzles are described. Variable nozzles are used to enhance the effectiveness of aircraft engines at various altitudes. The dynamic characteristics of variable nozzle mechanism including flaps are analyzed by a multi-body dynamics analysis software, RecurDyn.

• Wind and Structures
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• v.3 no.4
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• pp.221-241
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• 2000

Structural dynamics usually applies modal transformation rules aimed at de-coupling and/or minimizing the equations of motion. Proper orthogonal decomposition provides mathematical and conceptual tools to define suitable transformed spaces where a multi-variate and/or multi-dimensional random process is represented as a linear combination of one-variate and one-dimensional uncorrelated processes. Double modal transformation is the joint application of modal analysis and proper orthogonal decomposition applied to the loading process. By adopting this method the structural response is expressed as a double series expansion in which structural and loading mode contributions are superimposed. The simultaneous use of the structural modal truncation, the loading modal truncation and the cross-modal orthogonality property leads to efficient solutions that take into account only a few structural and loading modes. In addition the physical mechanisms of the dynamic response are clarified and interpreted.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.3
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• pp.132-138
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• 2004

In a vacuum circuit breaker mechanism, a spring-actuated linkage system is used to satisfy the desired opening and closing characteristics of electric contacts. If the type and structure of the linkage system required to the circuit breaker is predetermined, the stiffness, free length and attachment points of a spring become the important design parameters. In this paper, based on the energy conservation that the total system energy is constant throughout the operating range of the mechanism, a systematic procedure for optimizing the spring design parameters is developed and applied to the simplified mechanism of a circuit breaker. Then, in order to consider the complex dynamics of the circuit breaker mechanism rather well, the developed procedure is converted to the environment of a multi-body dynamics program ADAMS.

• Iberoamérica
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• v.12 no.1
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• pp.407-439
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• 2010

Growth of researches addressing cross-culture in international business is exponential. This article reviews the extant researches around the national culture and describes the various conceptualization of culture through discussion of some of popular models of national culture. This article presented some of the most important issues in international business surrounding globalization, especially convergence and divergence of cultures and cultural changes. Global rapid changes in international business environment request the reconsideration of the assumption of cultural stability and the simple view of culture, which tends to examine the static influence of a few cultural factors in isolation form other cultural factors and contextual elements. This paper identifies a valid cultural grouping and proposes the following typology of the possible methodologies in international business; Ethnological description, Use of proxies, Direct values inference, and Indirect values inference. Rather than selecting a single methodology, it appears to be more appropriate to use multi-method in the cross-cultural international business research. It has been shown that cultural change is intertwined with socioeconomic-institutional variables, and that these variables may also add to determine culture contemporarily. This paper also explained the dynamics of culture as multi-level, multi-layer constructs. According to this model, we may understand how the dynamic nature of culture conveys the top-down-bottom-up processes where one cultural level affects changes in other level of culture.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.3
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• pp.115-121
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• 2016

A mackerel grader is a machine for sorting mackerel according to size. In this study, the dynamic deflection and optimal sorting simulation of a mackerel grader was carried out by using multi-body dynamics. To analyze the dynamic deflection of the roller, RecurDyn, a multi-body dynamics analysis program, was used. The dynamic deflection of the roller pipe was analyzed according to the inclination of the roller pipe. When the inclination of the roller pipe was 30 degrees, the roller indicated the maximum deflection of about 6.3 mm at the center of the mass. To simulate the mackerel sorting, the mackerel grader machine was modeled, and the contact simulation between the mackerel model and the rotating roller pipe was carried out. When the inclination of the roller frame was 7 degrees, the mackerel grader indicated optimal sorting performance.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.9
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• pp.915-921
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• 2013

Most of large scale solar panel handling robots adopt the timing-belt drive system for its driveline because of the simplicity and the easiness of implementation. The vibration caused by the flexure of the timing belt would increase as the size and the weight of the panel that the robot handles increase and the vibration would deteriorate the precision and/or productivity of the whole robot system. For the development of a proper control system and for the improvement of the design of the robot it is important to estimate the oscillatory response of the robot system including the flexible drive system properly. In this paper a flexible multi-body dynamics model of a large-scale solar-panel-handling robot with the flexible timing-belt drive system is developed using a generic multi-body dynamics analysis program, RecurDyn.