• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.102-105
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• 1995

In power system stability analysis, modelling of the synchronous machine is necessary and vary important. In this paper, a synchronous machine is modeled and simulated by using Object-Oriented method. The mathematical equations describing the dynamic behavior of the synchronous machine is represented by block diagram and Objected-Oriented Digital Computer Simulater(ODCS). The developed method is tested for a one-machine-to-infinite-bus system, which is accurate and very useful for a multi-machine system simulation.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.10a
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• pp.365-369
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• 2002

This paper introduces that the machine tools's feed system optimizes by modeling for simulation and adjusting drive control parameter. The first method is frequency response of speed loop with design parameter by use of MATLAB application, in order that other axis can do equal to bandwidth. The second meted uses various sensor for analyzing machine tools's structure and adjustes jirk limitter.

• Journal of the Korea Management Engineers Society
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• v.23 no.4
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• pp.159-164
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• 2018

Human-machine serial systems must be normal in both systems. Though the failure of machine is irreducible by itself, the human errors are of recurring type. When the human performance is described quantitatively, non-homogeneous Poisson Process model of human errors can be developed. And the model parameters can be estimated by maximum likelihood estimation and numerical analysis method. System reliability is obtained by multiplying machine reliability by human reliability.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.708-713
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• 1997

A remote data communication system for monitoring of NC machine fault diagnosis and status is developed. This system communicates with host PC by using dial-up communication method on PSTN. The developed system consists of (1)remote communication module among NC's and host PC using PSTN, (2) 8 channels analog data sensing module, (3) digital I/O module for control of NC machine, (4) communication module between NC machine and remote data communication system using RS-232c, and (5) Software man-machine interface. This system may be applied for remote sensing of the status in Fms. To show the veridity of the developed system, several examples are illustrated.

• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.393-396
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• 2001

According to the development of power electronic element(GTO, IGBT) and material for electrical machines(permanent magnet, super conductor), the technology for electrical machines is nowaday rapidly developing. Here with, a novel electrical machine, based on the new conception of transverse flux configuration leads to a considerable Increase in power density and enables simultaneously high efficiency. The transverse flux machine with PM excitation will be applied to gearless direct drives for railway traction system and magnetic levitation system. The designed and measured performance of transverse machine for railway traction system and magnetic levitation system revealed a great potential of system improvements to reduce linear motor mass and increase efficiency.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.1022-1027
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• 1995

We present a framework of an intelligent design support system for embodiment design of machine tools which can support efficiently and systematically the machine design by utilizing design knowledge such as objects(part), know-how, public, evaluation, and procedures. The design knowledge of machining center has been accumulated through interview with design experts of machine tool companies. The processes of embodiment design of machining center are established. We also introduce a hybrid knowledge representation so that the systm can easily deal with various and complicated design knowledge. The intelligent design system is being developed on the basis of object-oriented programming, and all parts of a design object, machining center, are also classified by the object-oriented modeling. For the demonstration of effectiveness of the suggested system, a structural design system for machine tools is implemented.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.13 no.22
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• pp.71-78
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• 1990

Some problems to assess the safety of automated man-machine system are studied in many ways. The difficulty occurred in this system is the vagueness of human behavior. Fuzzy set theory is used to assess the human behavior in safety analysis. The unsafe behavior listed top 10 in accident statistics would be explained as the factors of human vagueness. Three cases are considered, which consist of man-machine system as man-man, man-machine, machine-machine types. For the design of safe task, using characteristics of work performance, each motion cycle time is required to know the rate of learning. Approach of human behavior to the standard motion means more safe motion. It is important to design the works as to minimize the time performance to the standard motion's, which utilize the control of risk potential with easy. In that process, use of fuzzy set theory is appropriate to analyze the human behavior to identify its vagueness.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.6
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• pp.1431-1440
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• 1993

This paper presents a new NC machine performance test and calibration system. In order to measure NC machine erros in simpler, and less time-comsuming way, some indirect measuring systems such as circular disk system and double ball bar system have been developed instead of laser interferometer. But these indirect measuring systems have shown their limits in identifying each of NC machine error sources in absolute numerical value. Therefore, we developed an unique NC machine error measurement system which provides a simple measuring process like other conventional indirect methods and still can indentify each of NC machine error sources in absolute numerical value.

• Journal of KIBIM
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• v.8 no.1
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• pp.24-32
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• 2018

A construction machine guidance system is an assistance system that helps construction equipment operators dig grounds during excavation work at a construction site. This system has long been applied in the overseas countries of the United States, Japan and Europe. However, the system has not been paid much attention in Korea. The objective of this paper is to present a business model for adopting construction machine guidance systems in Korea and evaluate the effectiveness of applying the system to excavation work. The business model in this study shows a new process of applying construction machine guidance system, business stakeholders and revenues, and suggests the benefits to the business stakeholders. A field test of the construction machine guidance system proves that the system can be applied as a tool that can improve the productivity of excavation work. This productivity improvement consequently demonstrates that the business model in this study is a prospective challenge in improving the effectiveness of excavation work at the construction site.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.86-89
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• 2005

Design and estimation of a spindle system which was composed of grinding spindle and regulating spindle for the centerless grinding of ferrule was performed and prototypes of each spindle were manufactured. Loop stiffness of the spindle system was 130 N/${\mu}m$. Although the value was lower than the target value of 150 N/${\mu}m$, as there included 20% of the safety factor, it was enough to machine the ferrule. Rotational accuracies of each spindle were about 0.2${\mu}m$ at the primary speed of 2,300 rpm(grinding spindle) and 300 rpm(regulating spindle). Temperature rises at the same speed were about $4.4\;\~\;4.7^{\circ}C$ in the case of grinding spindle and $1.8^{\circ}C$in the case of regulating spindle, which were well agreed with the designed value. From these results, it was estimated that the prototype of spindle system had a enough performances for the centerless grinding machine to machine the ferrule.