• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.56.1-56
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• 2001

Initial attitude error is one of the large error sources in the navigation errors of SDINS. And it is important to decide the initial attitude of SDINS. The method, like a self-alignment or a transfer alignment method, is required to a precise INS. If we do not have a precise INS, we should get large attitude error. After performing the initial alignment, a vehicle has the initial attitude error. Therefore, it results in navigation error due to the initial attitude error. But, if we use position information during flight, we could estimate and compensate a vehicle attitude error. So, we can maintain a precise attitude in spite of existing the initial attitude error. Using the uplinked position information from a land-based radar system, the new algorithm estimates the attitude of the SDINS during flight ...

• Journal of the Korean Society for Precision Engineering
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• v.17 no.5
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• pp.55-62
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• 2000

In this paper, an algorithm for determining the optimal resolution has been described for measuring the actual length of circular objects. As the resolution gets higher, the measurement error in general becomes smaller because of the reduced distance per pixel. However, the higher resolution makes circular objects enlarged, which may produce an ill-conditioned system. That is, a small error in the boundary positions may result in a large error in the analysis of the circular objects. Taking this fact into account, a new measure is proposed to determine the optimal resolution. The actual errors have been calculated with various resolutions and the resolution with the minimum error has been decided as the optimal resolution. The analysis using various circles with different sizes indicates that the minimum measurement error is obtained when the whole circle appears in the screen as large as possible, regardless of the size of circle. The experimental results using real images have verified the validity of our analysis.

• Journal of the Korea Safety Management & Science
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• v.8 no.1
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• pp.17-26
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• 2006

Basis frame-work's base in a semiconductor industry have gas, chemical, electricity and various facilities in bring to it. That it is a foundation by fire, power failure, blast, spill of toxicant huge by large size accident human and physical loss and damage because it can bring this efficient, connect with each kind mechanical, physical thing to prevent usefully need that control finding achievement factor of human factor of human action. Large size accident in a semiconductor industry to machine and human and it is involved that present, in system by safety interlock defect of machine is conclusion for error of behaviour. What is not construing in this study, do safety in a semiconductor industry to do improvement. Control human error analyzes in human control with and considers mechanical element and several elements. Also, apply achievement factor using O'conner Model by control method of human error. In analyze by failure mode effect using actuality example.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.8
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• pp.721-728
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• 2014

In this paper, it is proposed a method of optimizing path parameters for large-area laser processing. On-the-fly system is necessary for large-area laser processing of uniform quality. It is developed a MOTF(Marking On-The-Fly) board for synchronizing the stage and scanner. And it is introduced the change of the error due to the change of parameters and algorithm for large-area laser processing. This algorithm automatically generates stage path and a velocity profile using acceleration and deceleration parameters. Since this method doesn't use a G-code, even if without expert knowledge, it has an advantage that can be accessed easily. Angle of one of the square of $350{\times}350mm$ was changed from $50^{\circ}$ to $80^{\circ}$ and analyzed the error corresponding to the value of Ta. It is calculated the value of Ta of the best with a precision of 20um through measurement of accuracy according to the Ta of each angle near the edge.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.8
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• pp.1691-1697
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• 1997

This paper presents a new motion compensated error coding method suitable for region based image coding system. Compared with block based conding, the region based coding improves subjective quality as it estimates and compensates 2D (or 3D) translantional, rotational, and scaling motion for each regions. although the region based coding has this advantage, its merit is reduced as bock-DCT (2D-DCT) is used to encode motion-compensated error. To overcome this problem, a new region adaptive motion compensated error coding technique which improver subjective and objective quality in the region boundary is proposed in this paper. In the proposed method, regions with large error are estimated using contour of the regions and contrast between the regions. The regions estiated as those with large error are coded by arbitrarily shaped image segment coding method. The mask information of the coded regions is not transmitted because it is estimated as the same algorithm in the encoder and the decoder. The proposed region adaptive motion conpensated error coding method improves about 0.5dB when it is compared with conventional block based method.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.9 s.174
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• pp.69-76
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• 2005

The laser interferometer system such as HP5529A is one of the most powerful equipment fur measurement of the straightness error in precision stages. The straightness measurement system, HP5529A is composed of a Wollaston prism and a reflector. In this system, the straightness error is defined as relative lateral motion change between the prism and the reflector and computed from optical path difference of two polarized laser beams between these optics. However, rotating motion of the prism or the reflector used as a moving optic causes unwanted straightness error. In this paper, a compensation method is proposed for removing the unwanted straightness error generated by rotating the moving optic and an experiment is carried out for theoretical verification. The result shows that the unwanted straightness error becomes very large when the reflector is used as the moving optic and the distance between the reflector and the prism is far. Therefore, the prism must be generally used as the moving optic instead of the reflector so as to reduce the measurement error. Nevertheless, the measurement error must be compensated because it's not a negligible error if a rotating angle of the prism is large. In case the reflector must be used as the moving optic, which is unavoidable when the squareness error is measured between two axes, this compensation method can be applied and produces a better result.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1051-1054
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• 2003

For micro-weighing, null balance method is widely used in the precision industrial fields, such as biomedicine, semiconductor, chemistry and so on. In order to obtain high resolution and large measurement range simultaneously, the mechanism should be analyzed and optimized. However, large measurement error can be generated according to the mass loading position and this error is called as a corner loading error. The corner loading error is caused by the parallelism error of a Roberval mechanism used to minimize it. The corner loading error is one of the most dominant error sources that should be removed. It is possible to design that the mechanism has no corner loading error theoretically, but the mechanism of the micro weighing device is very difficult to be realized as original design due to assembling and manufacturing error. For the required specification of the device, the precise manufacturing technique under a few $\mu\textrm{m}$ is required for the realization of the design. In this paper, the effects of the parallelism error are analyzed by using Lagrange method and verified by experiment. Also, the compensation mechanism is proposed and the corner loading error is reduced by restoring tile parallelism.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.1031-1032
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• 2009

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.3
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• pp.111-120
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• 2004

This paper proposes a vector error diffusion method for smear artifact reduction in the boundary region. This artifact mainly results from a large accumulation of quantization errors. In particular, color bands with a smear artifact, the width of a few pixels appear along the edges. Accordingly, to reduce this artifact, the proposed halftoning process excludes the large accumulated Quantization error by comparing the vector norms and vector angles between the error-corrected vector and eight primary color patches. When the vector norm of the error corrected vector is larger than those of eight primary color patches, the quantization error vector is excluded from the quantization error distribution process. In addition, the quantization error is also excluded when the angle between eight primary color patches and error corrected vector is large. As a result, the proposed method enables a visually pleasing halftone pattern to be generated by all three color separations into account in a device- independent color space and reduces smear artifact in the boundary regions.

• Bulletin of the Korean Space Science Society
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• 2003.10a
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• pp.27-27
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• 2003

The Automated Quantitative Knife-Edge Test (AQuaKET) method was developed for testing the surface profiles of large optics with high accuracy. Testing with the required accuracy of very large telescope is not an easy job to achieve, as it is a nano-technology. There are lots of possible error sources which can occur during the measurements and in the data processing of the AQuaKET. The error sources can be categorized into 5 areas: optics, mechanics, electronics, numerical processes, and system. In this paper, possible error sources in Optics are discussed, which are intensity variation of the light source, diffraction effects, and parallax effect. In this talk, those possible error sources in optics are presented and discussed.