• Journal of Korea Game Society
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• v.9 no.6
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• pp.105-116
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• 2009

The motives of human beings provide reasons to set goals and carry them out. Accordingly, to realize the behaviors of agents similar to human beings, research using motives has been actively conducted. However, it is difficult for this research to cope with unexpected situations in a dynamic environment as does the research in a static environment. Agents can set goals by themselves in the dynamic environment. Furthermore, the goals that are finally selected shall be quickly and definitely set. This study suggests how to determine motives using them in order to enable agents to set goals by themselves. The suggested method compares motives generated by recognizing the environment by phase in real time and identifies the appropriateness of this method. The identified motives are used to set up the goals of agents and to practice the goals. For the appropriateness of the suggested method, the experiment to compare the behaviors of agents with different features in a virtual environment was conducted. The results of the experiment indicate that when several motives are generated, the agents found the most appropriate motive in the present situation. Accordingly, the agents were able to set up optimum goals so that they could cope with dynamic environments using the final motives identified by the determination of motives.

• Computers and Concrete
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• v.20 no.3
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• pp.297-310
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• 2017

A CFD software was used to simulate free surface flow of SCC in the T-Box test. In total, seven simulations were developed to study the effect of rheological parameters on the non-restricted flow performance of SCC in both horizontal and vertical directions. Different suspending fluids having five plastic viscosity values between 10 and 50 Pa.s, three yield stress values between 14 and 75 Pa, one density of $2500kg/m^3$, and one shear elasticity modulus of 100 Pa were considered for suspension of 178 spherical particles of 20-mm diameter and $2500kg/m^3$ density. The results of the simulations are found to correlate well to changes in rheological parameters of the suspending fluid. Plastic viscosity was shown to be the most dominant parameter affecting flowability and dynamic stability compared to the yield stress. A new approach was proposed to evaluate performability of SCC based on a trade-off between flowability and dynamic stability.

• Wind and Structures
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• v.8 no.4
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• pp.251-268
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• 2005

This paper describes the work of the International Association for Wind Engineering Working Group E -Dynamic Response, one of the International Codification Working Groups set up at the Tenth International Conference on Wind Engineering in Copenhagen. Comparisons of gust loading factors and wind-induced responses of major codes and standards are first reviewed, and recent new proposals on 3-D gust loading factor techniques are introduced. Then, the combined effects of along-wind, crosswind and torsional wind load components are discussed, as well as the dynamic characteristics of buildings. Finally, the mathematical forms of along-wind velocity spectra for along-wind response calculation and codification of acceleration criteria are discussed.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1999.11a
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• pp.318-322
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• 1999

An analytical study about dynamic behavior of center pivot rocker arm type valve train system equipped with roller of diesel engine is developed. At first, a mathematical model for the dynamic analysis has been set up using the lumped parameter method. In that model, valve spring is divided as some mass elemehts so as to simulate spring surging, Then, how the design parameters, such as valve mass, rocker arm inertia, valve spring stiffness, and initial load on valve spring, affect valve dynamic behavior especially in the valve close area is scrutinized.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1868-1873
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• 2011

In this paper, a theoretical formulation of a simplified wheel-set model for collision-induced derailments was evaluated by numerical simulations for the wheel-climb derailment and wheel-lift derailment types. The derailment types were classified into the wheel-climb derailment and the wheel-lift derailment according to the friction force direction of the wheel-flange. The wheel-climb derailment type was classified into Climb-up, Climb/Roll-over, and Roll-over-C, and wheel-lift derailment type was classified into Slip-up, Slip/Roll-over and Roll-over-L. To verify the theoretical equations derived for the wheel-climb derailment and the wheel-lift derailment, dynamic simulations using RecurDyn of Functionbay and Ls-Dyna of LSTC were performed and compared for some examples. The derailment predictions of the suggested theoretical formulation were in good agreement with those of the numerical simulations. The direction of the frictional force between the wheel-flange and the rail can be well predicted using the suggested derailment formulation at a initial derailment.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.880-884
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• 1995

Manufacturing environment is getting characterized by unstable market demand,short product life cycle and timebased competition. For adapting this environment,machine tools have to be further versatile functionally in order to reduce part's set-up time. Unlike existing manufacturing systems mainly to focus on part flow, it is important to control tool flow using fast tool change device and tool delivery device in parallel machines consisting of versatile machine tools, because complete operations on a part can be performed on one machine tool in a single machine set-up. In this paper, under dynamic tool allocation strategy to share tools among machine tools, we propose a real-time tool allocation and operation esequence model with an objective of minimizing flow time using autonomy and negotiation of agents in parallel machines

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.12B
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• pp.1051-1059
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• 2003

The key feature of GMPLS is the provision of network resources and the automatic set-up of a path. And the mechanism of protection and restoration of a path is presented when network component fails. This paper suggests CR-LDP Static Detour Mechanism and Dynamic Detour Mechanism. CR-LDP Detours are a mechanism to set up detour paths automatically at every node to protect working path. Hence suggested mechanism performance is compared with existing mechanisms by computer simulation.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2005.11a
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• pp.461-470
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• 2005

A dynamic supply chain that is composed of many different companies with different rent roles and interests allows free joining and secession. Buyers place orders simultaneously and manufacturers should compete each other for the orders. The purpose of our paper is how to find the optimal formation of supply chain ill a global viewpoint while allowing each member company to pursue his local goal The dynamic nature of supply chain formation causes the variation of cost depending on how many orders a manufacturer would accept. We propose a multi-agent based negotiation protocol that efficiently leads to the formation of optimal supply chain without giving up maximization of the individual profit in multi-agent environment of the make-to-order industry. The goal of the negotiation is to form a supply chain to minimize the overall sum of manufacturers' manufacturing cost, and earliness cost and tardiness cost based on SET model. We compare the negotiation protocol with Branch & Bound method. Finally, the validity and performance of buyer's negotiation has been tested experimentally.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.4 s.193
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• pp.84-92
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• 2007

Dynamic process planning requires not only more flexible capabilities of a CAPP system but also higher utility of the generated process plans. In order to meet the requirements, this paper develops an algorithm that can select machines for the machining operations by calculating the machine loads. The developed algorithm is based on the multi-objective genetic algorithm that gives rise to a set of optimal solutions (in general, known as the Pareto-optimal solutions). The objective is to satisfy both the minimization number of part movements and the maximization of machine utilization. The algorithm is characterized by a new and efficient method for nondominated sorting through K-means algorithm, which can speed up the running time, as well as a method of two stages for genetic operations, which can maintain a diverse set of solutions. The performance of the algorithm is evaluated by comparing with another multiple objective genetic algorithm, called NSGA-II and branch and bound algorithm.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.2
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• pp.47-55
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• 2012

This work deals with dynamic analysis of a monorail system with magnetic caterpillar where magnets are embedded inside each articulated element of the caterpillar, augmenting traction force of main rubber wheels to climb up slope up to 15 degree grade. Considerations are first given to determine stiffness of the primary and secondary suspension springs in order for the natural frequencies of car body and bogie associated with vertical, pitch, roll and yaw motion to be within generally accepted range of 1-2 Hz. Equations for calculating magnetic force needed to climb up given slope are derived, and a magnetic caterpillar system for 1/6 scale monorail is designed based on the derivation. To assess the hill climbing ability and cornering stability, and make sure smooth operation of the side and vertical guiding wheels which is critical for safety, a multibody model that takes into account of every component level design characteristics of car, bogie, and caterpillar is set up. Through hill climbing simulation and comparison with measurement of the limit slope, the validity of the analysis and design of the magnetic caterpillar system are demonstrated. Also by studying the curving behavior, maximum curving speed without rollover, functioning of lateral motion constraint system, the effects of geometry of guiding rails are studied.