• 전기의세계
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• v.20 no.1
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• pp.19-23
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• 1971

In testing the moving balance of a rotor instead of strobotron system here to for in use, making the pick up touch the rotor without putting the subject on the testing table, we can observe both the corrected original point and its unbalance point which appeared on the Braun tube screen with naked eyes. Then we can do our correcting job with rapidity.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.5
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• pp.7-14
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• 2008

• Journal of the Korean Society for Precision Engineering
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• v.18 no.6
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• pp.133-140
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• 2001

This paper suggests another system for a cutting force measuring tool in a milling process. Generally, tool dynamometer is taken into account for the most appropriate cutting force measuring tool in the analysis of cutting mechanism. However, high price and limited space make it difficult to be in-situ system for controllable milling process. Although an alternative method using AC current of servo-motor has been suggested, it is unsuitable for cutting force control because of small upper frequency limit and noise. The cutting force measuring system is composed of two load cells placed between the moving table bracket and the nut flange part of ballscrew. It has many advantages such as low cost and wide range measurement than tool dynamometer because of the built-in moving table and the low cost load cell. The static and dynamic model of the measuring system using imbeded load cell is introduced. Various Experiments are carried out to validate both models. By comparing the cutting forces from a series of end milling experiments on the tool dynamometer and the system developed in this paper, the accuracy of the cutting force measuring system is verified. Upper frequency limit is measured by the experiment of dynamic characteristics.

• Journal of the Korea Society of Computer and Information
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• v.12 no.6
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• pp.251-259
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• 2007

A Bluetooth ad hoc network can be formed by interconnecting piconets into scatternet. Many algorithms of scatternet formation have been proposed so far. However, these have a problem that takes a long time to reform scatternet, especially for the case of master moving out. In this paper we propose a Fast-Recovery algorithm. which aims at reducing the time of scatternet reformation owing to master moving out. In the algorithm, we select a slave with the weigh similar to its master as Sub-Master from a piconet device table created by the master When a master leaves its piconet is detected by its slaves, the Sub-Master becomes the new master of the piconet instead of the old and directly connect to other slaves and bridge(s) through piconet device table in page state.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.7
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• pp.125-132
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• 2002

This paper shows an experimental magnetic levitation table using one degree-of-freedom active control. The magnetic levitation table using repulsions of permanent magnets was theoretically presented already. Thus the objective of this paper is to prove stable levitation with only one degree-of-freedom active control experimentally. For the design of the system, at first, permanent magnets are selected. Secondly, the spring constants of the virtual spring are obtained by simulation. Thirdly, the moving magnets are arranged using a stable layout relation. Fourthly, a linear voice coil motor is designed. Finally, the magnetic levitation system is manufactured. The phenomenon of stable levitation in the manufactured table is proven by means of dynamic time and frequency responses. The differences between the theoretical natural frequencies and experimental ones are analyzed. Also, stable range in the control direction is shown experimentally.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37C no.10
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• pp.859-869
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• 2012

In this paper, a new method to efficiently generate the 3-D(three-dimensional) video holograms for 3-D moving scenes, which is called here the TSR-N-LUT method, is proposed by the combined use of temporal-spatial redundancy(TSR) of 3-D video images and novel look-up table(N-LUT) technique. That is, in the proposed scheme, with the differential pulse code modulation (DPCM) algorithm, temporally redundancy redundant data in the inter-frame of a 3-D video images are removed between the frames, and then inter-line redundant data in the inter-frame of 3-D video images are also removed by using the DPCM method between the lines. Experimental results show that the proposed method could reduced the number of calculated object points and the calculation time of one object point by 23.72% and 19.55%, respectively on the average compared to the conventional method. Good experimental results with 3-D test moving pictures finally confirmed the feasibility of the proposed method to the fast generation of CGH patterns of the 3-D video images.

• Journal of the Korean Data and Information Science Society
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• v.8 no.2
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• pp.153-161
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• 1997

A Korean exporience life table(male) is constructed by using a mixture of weighted moving average(WMA) model and Gompertz' parametric survival model based on 25,000,000 insured of major 6 life insurance companies from 1988 to 1992. The graduated values are taken as those which minimize the composite measure of fittness and smoothness. Moreover, we propose closed form estimators for three parameters of Gompertz' model.

• International Journal of Safety
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• v.9 no.1
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• pp.54-57
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• 2010

The LHP uses the capillary head instead of the mechanical pump to transfer the fluid. It does not have any moving parts and transfer the fluid by the capillary head between the vapor and liquid interface of the wick like a heat pipe (HP). Moreover, vapor and liquid flows in the same direction. It can reduce the loss of the pressure in the wick (very short wick in the evaporator) and can transfer large heat over long distance compared with HP. It is necessary that we do the hazard analysis that is a part of the safety design, for the benefit of eliminating and inhibit the hazard. In this paper, we describe the hazard analysis of LHP.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.295-295
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• 2000

In this paper, the measurement algorithm of PCB alignment error is developed using image processing. The X-Y-$\theta$ table correcting PCB alignment error is driven by drive module based on microprocessor according to calculation results obtained through image processing procedure. In order to recognize the X-Y-$\theta$ position errors, two fiducial points are marked on PCB and two cameras of ultraviolet rays types are used for detection of the points to capture exactly fiducial points under disturbance of illumination change. Through application for a practical screen printer, the precision control using the developed position control system can be realized about 2.5${\mu}{\textrm}{m}$ in table moving range and 8${\mu}{\textrm}{m}$ in camera processing precision.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.26 no.2
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• pp.257-261
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• 2017

Drilling file is medical mini-drill which is made of Ni-Ti material and has tapered shape. It's for removing teeth nervine which helps the endodontic treatment. All files, saled at domestic market, are imported from U.S. and Europe. Also they have low manufacturing efficiency and high price because it is made by universal 5 axis CNC grinding machine. To solve these problem, 3 axis CNC table, controllable tilting angle spindle and helix angle moving table are devised. To confirm divised CNC grinding machine's manufacturing accuracy, conveying amount and finish product size measurement expreiment has been practiced. Also to automate all manufacturing processes, automatic mechanism is designed.