• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.04a
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• pp.416-423
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• 2004

This paper presents the thermal characteristic analysis of a high-speed horizontal machining center with spindle speed of 50,000rpm and feedrate of 120m/fin. The spindle system is designed based on the built-in motor, angular contact ceramic ball bearings, oil-air lubrication and oil-jacket cooling method. The X-axis and Y-axis feeding systems are composed of the linear motors and linear motion guides, and the Z-axis feeding system is composed of the servo-motor, ball screw and linear motion guides. The thermal characteristics such as the temperature distribution, temperature rise, thermal deformation and step response, are estimated based on the finite element model of machining center and the heat generation rates of heat sources related to the machine operation conditions. Especially, the thermal time constant assessed from the step response function is introduced as an index of thermal response characteristics.

• Journal of the Korean Institute of Telematics and Electronics
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• v.6 no.3
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• pp.1-7
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• 1969

The Series RC load is connected with the word line in an attempt to select with high speed the information from the coincident current magnetie memory core. By taking the small time constant of the RC load, the cycle time of the output pulse is shortened by about 2 microseconds to 3 micro seconds. For this purpose, the analytical study are accomplished and the optimum circuit parameters are determined. Furthermore, the thermal problems occuring from the high speed switching of the magnetic memory core have been clarified.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.13 no.5
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• pp.30-37
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• 2004

This paper presents the thermal characteristic analysis of a high-speed horizontal machining center with spindle speed of 50,000rpm and feedrate of 120m／min. The spindle system is designed based on the built-in motor, angular contact ceramic ball bearings, oil-air lubrication and oil-jacket cooling method. The X-axis and Y-axis feeding systems are composed of the linear motors and linear motion guides, and the Z-axis feeding system is composed of the servo-motor, ball screw and linear motion guides. The thermal characteristics such as the temperature distribution, temperature rise, thermal deformation and step response, are estimated based on the finite element model of machining center and the heat generation rates of heat sources related to the machine operation conditions. Especially, the thermal time constant assessed from the step response function is introduced as an index of thermal response characteristics.

• Journal of the Korea Society for Simulation
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• v.29 no.1
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• pp.71-79
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• 2020

As the urbanization trend in modern society continues, the concentration of the population induces the urban problems in the residential area. One of the well-known issues among various urban problems is the garbage problem, which causes deterioration of the residential environment of citizens and directly affects the satisfaction of municipal administration. Such garbage problem cannot be accurately predicted by analyzing the amount of waste emitted from residential areas, but it is necessary to analyze the lifestyle and characteristics of residents living in residential areas. In this study, we propose an agent-based residential modeling and simulation environment using discrete event system formalism to analyze the garbage problem and satisfaction level according to the distribution of residents in the residential area. To model the behavior of the residents, we utilized the Atomic Model to capture the temporal behavior. Also, we used the Coupled Model to model the multi-family and the building to enhance the reusability of the simulation model. Also, this study carried out simulation modeling and simulation for a multi-family residential area. The simulation results of the multi-family housing area show that considering the characteristics of the residents gives better results compared to the simulation results without considering the characteristics.