• 한국컴퓨터그래픽스학회논문지
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• 제4권1호
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• pp.41-46
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• 1998

현재와 같이 그래픽을 기반으로 하는 멀티미디어 환경에서 이미지 데이터의 압축과 재생을 위한 이미지 처리 기법은 생성되는 커다란 크기의 데이터 처리를 고려해야 한다. 이를 위하여 여러 가지 기법이 제안되었고 Wavelet과 JPEG등과 같은 기법으로 바람직한 결과를 얻었다. 본 논문에서는 기존의 supremum metric보다 효과적인 root mean square metric에 대하여 연구하였고 이를 수학적으로 비교, 검증하였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1080-1085
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• 2003

The flow of electrical current through a microscopic actual contact spot between two conductors is influenced by the flow through adjacent contact spots. A smoothed version of this interaction effect is developed and used to predict the contact resistance when the statistical size and spatial distribution of contact spots is known. To illustrate the use of the method, an idealized fractal rough surface is defined using the random midpoint displacement algorithm and the size distribution of contact spots is assumed to be given by the intersection of this surface with a constant height plane. With these assumptions, it is shown that including finer scale detail in the fractal surface, equivalent to reducing the sampling length in the measurement of the surface, causes the predicted resistance to approach the perfect contact limit.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회/대한산업공학회 2005년도 춘계공동학술대회 발표논문
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• pp.1124-1128
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• 2005

In this paper, a plan-coordination architecture is proposed for multi-agent control in the fractal manufacturing system (FrMS). A fractal in FrMS is a set of distributed agents whose goal can be achieved through cooperation, coordination, and negotiation with other agents. Since each agent in the FrMS generates, achieves, and modifies its own plan fragments autonomously during the coordination process with other agents, it is necessary to develop a systematic methodology for the achievement of global plan in the manufacturing system. The heterarchical structure of the FrMS provides a compromised plan-coordination approach, it compromise a centralized plan-generation/execution (which mainly focuses on the maximization of throughput) with a distributed one (which focuses on the autonomy of each module and flexibility of the whole system). Plan-coordinators in lower level fractal independently generate plan fragments according to the global plan of higher level fractal, and plan-coordinators in higher level fractal mediate/coordinate the plan fragments to enhance the global performance of the system. This paper assumes that generation method of the plan fragments and the negotiation policy of the fractal is achieved by a simple process, and we mainly focuses on the information exchanging and distributed decision making process to coordinate the combinations of plan fragments within a limited exchange of information.

• Tribology and Lubricants
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• 제30권6호
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• pp.378-383
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• 2014

This study predicts the of the hysteretic friction of a rubber block sliding on an SMA asphalt road. The friction of filled rubber on a rough surface is primarily determined by two elements:the viscoelasticity of the rubber and the multi-scale perspective asperities of the road. The surface asperities of the substrate exert osillating forces on the rubber surface leading to energy dissipation via the internal friction of the rubber when rubber slides on a hard and rough substrate. This study defines the power spectra at different length scales by using a high-resolution surface profilometer, and uses rubber and road surface samples to conduct friction tests. I consider in detail the case when the substrate surface has a self affine fractal structure. The theory developed by Persson is applied to describe these tests through comparison with the hysteretic friction coefficient relevant to the energy dissipation of the viscoelastic rubber attributable to cyclic deformation. The results showed differences in the absolute values of predicted and measured friction, but with high correlation between these values. Hence, the friction prediction model is an appropriate tool for separating the effects of each factor. Therefore, this model will contribute to clearer understanding of the fundamental principles of rubber friction.