• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1446-1449
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• 2008

Immune system is composed of multiple cells with distinct functions, and immune responses are orchestrated by complex and dynamic cell-cell interactions. Therefore, each cell behavior and function should be understood under right spatio-temporal context. Studying such complexity and dynamics has been challenging with conventional biological tools. Recent development of new technologies such as state of art imaging instruments and microfabrication techniques compatible with biological systems have provided many exciting opportunities to dissect complex and dynamic immune cell interactions; new microscopy techniques enable us to observe stunning dynamics of immune system in real time. Microfabrication permits us to manipulate microenvironments governing molecular/cellular dynamics of immune cells to study detailed mechanisms of phenomena observed by microscopy. Also, microfabrication can be used to engineer microenvironments optimal for specific imaging techniques. In this presentation, I am going to present an example of how these two techniques can be combined to tackle challenging problems in immunology. Obviously, this strategy can readily be applied to many different fields of biology other than immunology.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.842-846
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• 1996

Leaf springs are widely used as a major suspension component in many commercial vehicles, such as buses, trucks, etc. They have a complex dynamic behavior due to the geometric nonlinear and the contact mechanism between the leaves. The interface conditions between the leaves play a significant role in the global behavior of the comfort and ride of the vehicle system. The paper concentrates on modeling leaf springs and contact frictions between the leaves using a nonlinear finite element approach. A nonlinear load-displacement hysteresis curve for the leaf spring is simulated and its results are compared with test results.

• East Asian mathematical journal
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• v.31 no.3
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• pp.351-356
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• 2015

In this paper, we study holomorphic discs in a domain with a plurisubharmonic peak function at a boundary point. The aim is to describe boundary behavior of holomorphic discs in convex finite type domains in the complex Euclidean space in term of a special local neigh-borhood system at a boundary point.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.04a
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• pp.398-405
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• 2001

Upper wall-lower frame(complex building) can be divided into three partition, namely, upper wall, lower frame, and transfer system which link two partitions. The purpose of this study is to investigate the elasto-plastic response characteristics of structures with variation in the stories of lower frame of complex buildings. The conclusions of this study was following; 1) In the push-over analysis for vertically irregular building, the distribution of lateral forces is judged which consider the effects of higher mode. 2) In proportion as the stories of lower frame increase inter-story displacement of lower frame increased, but that of upper wall decreased. 3) The appearance of yielding hinge with variations in the lower stories of complex buildings differed in lower frame of each model, but was almost the same in upper wall.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.3
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• pp.33-45
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• 1997

In this paper, we propsoe a new method of th ecommunication system for cooperative behaviors and works in collective autonomous mobile robots. A communication function among the collective robots is essential to intelligent cooperative works. In genral, global communication is effective for small number of robots. However when the number of robot goes on increasing, this becomes difficult to be realized because of limited communication capacity and increasing amount of information to handle. And also the problems such as communciation interfeence and improper message transmission occur. So we propose local communication system based on infrared sensor to realize the cooperative behavior among robots as the solution of above problem. It is possible to prevent overflow of information and exchange of complex information by fusion sign board model which transmits the information to unspecified robots and message passing model which communicate a specific robot. And we formularize optimal communication range by analysis of information propagation mechanism from the proposed comunication system. At last we verify the effectiveness of the proposed communication system from example of cooperative works.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.59.5-59
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• 2001

Multi-agent robot system is the system which executes by cooperating with each robots and controlling several robots. Capability and function of each robot must be considered for cooperation behavior. Furthermore, it is necessary to analyze the given environment and to replace complex task with some simple tasks. Analysis of the given environment and role assignment for the given tasks are composed of discret event. In this paper, the hierarchical controller for multi-agent robot system using the petri-net state diagram is proposed. The proposed modeling method is implemented for soccer robot system. The effectiveness of proposed modeling method is shown through experiment.

• International Journal of Computer Science & Network Security
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• v.23 no.5
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• pp.21-32
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• 2023

The design of complex man-made systems mostly involves a conceptual modeling phase; therefore, it is important to ensure an appropriate analysis method for these models. A key concept for such analysis is the development of a diagramming technique (e.g., UML) because diagrams can describe entities and processes and emphasize important aspects of the systems being described. The analysis also includes an examination of ontological concepts such as states and events, which are used as a basis for the modeling process. Studying fundamental concepts allows us to understand more deeply the relationship between these concepts and modeling frameworks. In this paper, we critically analyze the classic definition of a state utilizing the Thinging machine (TM) model. States in state machine diagrams are considered the appropriate basis for modeling system behavioral aspects. Despite its wide application in hardware design, the integration of a state machine model into a software system's modeling requirements increased the difficulty of graphical representation (e.g., integration between structural and behavioral diagrams). To understand such a problem, in this paper, we project (create an equivalent representation of) states in TM machines. As a case study, we re-modeled a state machine of an assembly line system in a TM. Additionally, we added possible triggers (transitions) of the given states to the TM representation. The outcome is a complicated picture of assembly line behavior. Therefore, as an alternative solution, we re-modeled the assembly line based solely on the TM. This new model presents a clear contrast between state-based modeling of assembly line behavior and the TM approach. The TM modeling seems more systematic than its counterpart, the state machine, and its notions are well defined. In a TM, states are just compound events. A model of a more complex system than the one in the assembly line has strengthened such a conclusion.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.61-64
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• 2006

A common form of construction for apartment buildings consists of walls and coupling element. But, the structural behavior of coupling element are very complex and affected by the properties of coupling element. The propose of this paper is to evaluation the behavior of coupling element in wall-dominant system. An 1/2 scale three specimens was constructed and under cyclic loads. The specimen was consisted of opening walls and coupling element as well as floor slabs. From the result of this study, in coupling slabs, the stresses were not uniform across the width. And the effective width of coupling slabs was found smaller than the that of predicted from previous studies.

• Journal of the Korean Society of Safety
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• v.15 no.1
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• pp.1-10
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• 2000

This paper deals with rocking response behavior of rigid block structure subjected to horizontal excitation. A strict consideration of impact and sliding between the block and base is essential to investigate the rocking vibration characteristics because the rocking behavior were greatly influenced by the impact and sliding motion. Therefore, not only restitution coefficient between the block and base but also the energy dissipation rate which is associated with sliding motion, and the static and kinetic friction coefficient between those should be included in the modeling of rocking system. The analytic program was developed to be able to simulate the experimental responses of the block subjected to horizontal sinusoidal excitations. By using this program, rocking responses were numerically calculated by the nonlinear equations for rocking system. From the response simulation and rocking vibration experiment, the following results were obtained. The rocking responses are affected by the impact motion due to energy dissipation and friction and provide very complex behavior. The toppling condition of the block is also influenced by the impact motion and sliding motion.

• Journal of the Korean Society of Safety
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• v.14 no.4
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• pp.3-12
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• 1999

This research concentrates on the influence of non-linearities associated with impact for the nonlinear rocking behavior of rigid block subjected to one dimensional sinusoidal excitation of horizontal direction. The transition of two governing rocking equations, the abrupt reduction in the kinetic energy associated with impact, and sliding motion of block. In this study, two type of rocking vibration system are considered. One is the undamped rocking vibration system, disregarding energy dissipation at impact and the other is the damped rocking system, including energy dissipation and sliding motion. The response analysis using non-dimensional rocking equation is carried out for the change of excitation parameters and friction coefficient. The chaos responses were discovered in the wide response region, particularly, for the case of high excitation amplitude and their chaos characteristics were examined by the time history, Poincare map, power spectra and Lyapunov Exponent of rocking responses. The complex behavior of chaos response, in the phase space, were illustrated by Poincare map. The bifurcation diagram and Poincare map were shown to be effective in order to understand chaos of rocking system.