• Journal of the Korean Society of Manufacturing Process Engineers
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• v.8 no.4
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• pp.41-47
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• 2009

This research deals with evaluation of machining accuracy for Parallel Kinematic Machine Tool(PKMT) applied parallel type robot system with high precision and stiffness. For this purpose, machine simulation is carried out to foreknow collision and interference between workpiece and tool. Furthermore, on the basis of machine simulation data, PKMT is manufactured. Machining accuracy such as cylindricity straightness, squareness, parallelism circularity, concentricity pitch error and yaw error, is measured by using coordinate measuring machine. Test piece for evaluation of machining accuracy is designed and manufactured under the standard of ISO 10791-7.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.153-154
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• 2006

Development of sorting machine for photo diode and its control system is addressed. The sorting machine for optical communication device requires high positional precision because the alignment is one of the most important point in the sorting process. This sorting method describes how to detect the target chip's angle and position from the wafer. The machine vision system is used for the feedback control. This sorting machine is implemented by motion controller, machine vision and various solenoid valve and is interfaced with RS-232c, GPIB and PCI communication. This system gets the position accuracy within $1{\mu}m$ with our experiments.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.11
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• pp.30-35
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• 2021

In this study, a machine simulation system was built using the actual scale of an AC-type 5-axis machine tool for mold surface machining that can be used in applications, such as, modeling and machine building, stroke, and collision detection. The validity of the 5-axis machine simulation system was verified by performing tool path generation, post-processing, machine simulation, prototype motion simulation, and an actual cutting experiment. This entire process was intended to activate the 5-axis machining in mold surface machining.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.1
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• pp.229-239
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• 2003

The design process of machine tools is regarded as a sequential, discrete, and inefficient works as it requires various kinds of design tools and many working hours. This paper describes an integrated design system embedding a design methodology that can support efficiently and systematically the conceptual structural design of machine tools. The system is a knowledge-based design system and has four machine-tool-specific functional modules including configuration design, configuration analysis, structure design, and structural analysis support module. Through the configuration design and analysis module, a machine configuration appropriate for design requirements is selected, and then the arrangement of ribs fer each structural part is decided in the structure design module. Also, the structural analysis support module is used to evaluate design result by utilizing structural analysis software, ANSYS. The system is applied to design of a tapping machine, and shows that the machine structure can be designed fast and conveniently by processing each design step interactively.

• IE interfaces
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• v.12 no.4
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• pp.532-539
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• 1999

The first step to design a cellular manufacturing system is to make part-families and machine-cells. This process is called the machine-part grouping. This paper considers a machine-cell size when grouping machine-cells. By considering a machine-cell size, an unrealistically big size of machine-cell which may be caused by the chaining effect can be avoid. A heuristic algorithm which minimizes the number of inter-cell movement of parts considering a machine-cell size is presented. The effectiveness and performance of the proposed heuristic algorithm are compared with those of several heuristic algorithms previously reported. The comparison shows that the proposed heuristic algorithm is efficient and reliable in minimizing the number of inter-cell movement of parts and also prevents the chaining effect.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1852-1857
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• 2003

This study is concerned about the development of three-dimensional bending machine for heat exchanger. Recently, three-dimensional bending is required for various heat exchanger. The purpose of this study is design of three-dimensional bending machine by analysis of bending process and structural analysis simulation. The analysis is carried out by FEM simulation using DEFORM and CATIA V5 software. The copper-tube is modeled by shell elements and the machine is modeled by placing proper shell and solid finite elements and fictitious mass properties to represent the real one. The final results of analysis are applied to the design of three-dimensional bending machine and the machine is successfully developed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.1134-1139
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• 2003

Vibration problems are an intrinsic characteristic in a washing machine owing to rotation working mechanism. Therefore, a right comprehension of working principle and the analysis on dynamic behavior of a washing machine is essential to design anti-vibration or vibration reduction. In this paper, we choose two kinds of a washing machine: a suspension type pulsator/drum type washing machine. Each the structure and working principle of a washing machine is discussed briefly and the dynamic behavior of it is investigated, then, the vibration detection problems of transient or excessive vibration is tented in each category. Some vibration experimented results in a washing machine are presented also.

• Journal of the Korea Safety Management & Science
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• v.23 no.3
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• pp.27-33
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• 2021

The purpose of this study is to present a novel indicator for analyzing machine failure based on its idle time and productivity. Existing machine repair plan was limited to machine experts from its manufacturing industries. This study evaluates the repair status of machines and extracts machines that need improvement. In this study, F-RPN was calculated using the etching process data provided by the 2018 PHM Data Challenge. Each S(S: Severity), O(O: Occurence), D(D: Detection) is divided into the idle time of the machine, the number of fault data, and the failure rate, respectively. The repair status of machine is quantified through the F-RPN calculated by multiplying S, O, and D. This study conducts a case study of machine in a semiconductor etching process. The process capability index has the disadvantage of not being able to divide the values outside the range. The performance of this index declines when the manufacturing process is under control, hereby introducing F-RPN to evaluate machine status that are difficult to distinguish by process capability index.

• Proceedings of the Technology Innovation Conference
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• 1996.12a
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• pp.154-178
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• 1996

This paper applies the technology-gap trade theory to explaining radical changes in the competitive positions of countries in world machine tool markets over the last three decades. It develops the notion that the innovation gaps in machine tools among countries led to the inter-country differences in the competitive performance in the sector as well as in its user sectors. Since competitive advantage largely depends on a capability to improve, create and apply technology to market competition, a higher innovative performance in one country than another is closely related to a higher innovative performance. A higher innovative performance in machine tools is also associated with a higher competitive performance of the large areas of its user sectors, due to sectoral interdependences and externalities generated by machine tool innovations. The results of empirical investigation through a panel data analysis show that the international gaps in machine tool innovations appeared to have a positive significant relationship with the differences in the export performance of both the machine tool sector and its user sector across countries.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.3
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• pp.357-360
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• 2011

Machine tools of Gantry type have been performing machine work as a moving machinery. In a large machine tools, the machinery is moving with bed and it is structurally unstable. When the objects are processed, machine tools gets loads in the direction of Z-axis. In other words, the machine tools which become bigger was performed by the trend of complexation. It made that the increased machine weight can't be passed over. In order to enhance manufacturing precision, it needs to compensate Z-axis deflection of weight for machine tools. In this paper, Machine tools of Gantry type were miniaturized and deflection was measured by LVDT sensors. When deflection was measured, block mass weighted 50kg is moving on particular distance. Then, the displacement of fixed point and moving point is measured by recording telemeter.