• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1415-1418
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• 1997

An accurate length measuring system has been develope by a modified Michelson interferometer. A frequency stabilized laser source and a 20 fold frequency interpolation and digitizing circuit were applied to the system. Resolutioin of .lambda./40, 16 nm, was achieved from the discrete length measuring system. In order to obtain a resoltuion of 1.mu.m a decimalizing module was designed for the 0.016.mu.m resolution system. The refractive index of the ambient air was calibrated on the decimalizing module through the Edlen's formula. Performance of the system was evaluated on the machining center in short and long length measruements.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10b
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• pp.530-533
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• 1993

This paper describes a new method of dynamic error compensation, using a digital convolution integrator and two digital low pass filters. In this method, the process of compensation consists of three steps. First, sampling and digitizing of input signal, second, removing the noise in sampled data by the low pass filter and third, making a convolution integral using the output data of low pass filters. This method showed a good experimental result of reducing dynamic error even if there was a slight noise in the input signal. As a result, the detecting time constant of resistance thermo-bulb was improved to about 1/10th.

• Korean Journal of Computational Design and Engineering
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• v.6 no.1
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• pp.40-47
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• 2001

In reverse engineering, existing products are digitized fur the computer modeling. Using the digitized data, surfaces are modeled for new products. However, in the digitizing process measuring errors or deviations can be happened often in practice. Thus, it is important to adjust such errors or deviations during the computer modeling. To adjust the errors, fairing of the modeled surfaces is performed. In this paper, we present a surface fairing algorithm based on various fairness metrics. Fairness metrics can be discrete. We adopt discrete metrics for fairing given 3D point set. The fairness metrics include discrete principal curvatures. In this paper, automatic fairing process is proposed for fairing given 3D point sets for surfaces. The process uses various fairness criteria so that it is adequate to adopt designers'intents.

• Journal of Mechanical Science and Technology
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• v.17 no.4
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• pp.545-561
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• 2003

We use the first-passage-time formulation by Torquato, Kim and Cule ［J. Appl. Phys., Vol. 85, pp. 1560∼1571 (1999) ］, which makes use of the first-passage region in association with the diffusion tracer's Brownian movement, and develop a new efficient Brownian motion simulation method to compute the effective conductivity of digitized composite media. By using the new method, one can remarkably enhance the speed of the Brownian walkers sampling the medium and thus reduce the computation time. In the new method, we specifically choose the first-passage regions such that they coincide with two, four, or eight digitizing units according to the dimensionality of the composite medium and the local configurations around the Brownian walkers. We first obtain explicit solutions for the relevant first-passage-time equations in two-and three-dimensions. We then apply the new method to solve the illustrative benchmark problem of estimating the effective conductivities of the checkerboard-shaped composite media. for both periodic and random configurations. Simulation results show that the new method can reduce the computation time about by an order of magnitude.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1997.10a
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• pp.230-234
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• 1997

Reverse engineering involves digitizing a three-dimensional model or part converting the data to a CAD database description and manufacturing by CNC. Currently, the digitization is done through measurements taken manually by a CMM or touch probe mounted on a CNC machinetool. Some reverse engineering techniques require close integration between the data collection method and the surface-fitting algorithms. Accurate surface data are collected by input to the surface fitting method. This study has been found that both the smoothness of surfaces and accuracy of surface fitting are related with the degree of the interpolated surfaces.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1997.10a
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• pp.207-212
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• 1997

The purpose of this study is the development of CAM system which can cut and measure any shape by machining center and coordinate measuring machine. The overall goal of the CAM system is to achieve the CNC machining, from digitizing through to final cutting. The hardware of the system comprises PC and machining center, CMM. There are three steps in the CNC machining, (1) workpiece measuring on the CMM, (2) geometric modeling by the CAD system, (3) NC commands generation by the tool path compensated for tool nose radius. It is developed a software package, with which can conduct a micro CAM system in the PC without economical burden.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.4
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• pp.303-309
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• 2014

This paper contains how to integrate production resources of 4M1E (Man, Machine, Material, Method and Energy), analyze and collect various type of management information which emphasize the need of a common platform's 4M1E Middleware and Autonomous Configuration. Management efficiency improved by the functionality of integrated management information and digitizing information with standardized data.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.10a
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• pp.417-422
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• 1993

In order to minimize turnaround of machining in FMS lines, CAD/CAM/CAT integrated system called MascCAM was developed. Developing enhanced CAM and inspection modules in the MascCAM environment, 2D came, 2 $^{1}$2/ D prismatic parts and 3D free-formed surfaces were able to be automatically designed, manufactured and inspected on the machine tools by using AutoCAM and Z-map. Introducing Z-map technique, the MascCAM was able to be interfaceed with and CAD system. Developed QPPGT module generates a quick and fool-proof inspection work to users. A vertical and a horizontal machining center equipped with FANUC OMC were used for experiments. Performance of the system was confirmed by a large amount of experiments.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.272-275
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• 2005

The digital map expresses natural topographies and artificial things with 3D position coordinates in the computer such as the road, railway, building, river, mountain, paddy and dryland. Therefore, the digital map is regarded as an important factor in the information-oriented society. However, it is difficult to maintain the most recent topographic information all the times because of restricted budget and time. For that, the efficient method corresponded with the digital map should be presented. This study aims to suggest the way to make an estimate of updating cost for 1:5,000 scale digital map by using remotely sensed data. To predict updating area of the digital map, the screen digitizing method was applied to the overlapped images and digital maps.

• Proceedings of the KIEE Conference
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• 2003.11b
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• pp.83-86
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• 2003

This paper is the research and development including the system design and the prototype system building of the wide-band digital autocorrelation spectrometer system for radio astronomy observation, which will be used as back-end signal processing unit of the Dual channel SIS receiver at Taeduk Radio Astronomy Observatory. So in this paper. we performed development of the high speed digitizing sampler, the circular memory buffer, and the correlator module for the 400MHz wide-band digital autocorrelator.