• Proceedings of the Korean Information Science Society Conference
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• 2002.04a
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• pp.475-477
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• 2002

Mobile ad hoc network은 관리나 표준화된 지원 서비스 없이 무선 이동 노드들만으로 구성되는 임시적인 망이다. Mobile ad hoc network에서는 노드들의 이동성으로 인해 각각의 노드들이 경로를 결정하고, 경로가 무효화되었을 때 빠르고 효과적으로 복구하는 것이 중요하다. 본 논문에서는 On-Demand 방식의 대표적인 프로토콜인 AODV에서 경로 설정 과정과 경로 파손이 발생했을 때 경로 재설정 과정을 알아보고, 액티브 경로의 길이가 망의 직경에 가깝게 확장되어 졌을 경우에 경로 설정 과정에서 흡수를 이용해 mark-up 한 노드들과 RREP 전송과정에서 mark-up한 노드에 의한 부분적인 다중 경로를 설정함으로서 보다 효과적이긴 신뢰성 있는 새로운 경로 재설정 기법을 제안한다.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.6 s.183
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• pp.187-195
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• 2006

FDM, SLS, and EOS processes are the layered manufacturing processes far functional prototypes. In this paper, bench mark tests of those processes were carried out using various materials. The test includes mechanical properties, such as tensile and compressive strengths, hardness, impact strength, and heat resistance, and surface roughness, shape and dimensional accuracy, manufacturing time, and manufacturing costs. It is verified that SLS method is advantageous in surface roughness and manufacturing time, EOS method in shape accuracy, and FDM method is great in manufacturing costs.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1804_1805
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• 2009

최근 여러 산업 분야에서는 품질의 향상과 생산성을 높이기 위해 자동화 검사 장치 개발이 활발하게 연구 되고 있다. 본 연구에서는 비전을 이용한 신뢰도 높은 슬라브(Slab) 표면 검사 자동화 알고리즘의 전처리 단계인 오실레이션 마크(Oscillation mark) 검출을 목표로 한다. 슬라브 영상의 경우 조업시에 발생하는 산화 물질인 스케일(Scale)이 영상 전체에 분포하고 있으며, 이러한 스케일은 형태적 특징 및 밝기 특징이 일정치 않기 때문에 오실레이션 마크 검출 성능을 저하 시킨다. 따라서 스케일의 영향을 최소화 하고 효과적으로 오실레이션 마크를 검출하기 위해 가버 필터(Gabor filter)와 수직 투영 프로파일(Vertical projection profile)을 이용한 노이즈 제거 방법을 사용한다.

• Journal of Korean Institute of Industrial Engineers
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• v.27 no.3
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• pp.305-314
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• 2001

In this paper, we construct an automatic evaluation system of psychological feeling for corporate identity (CI) symbol mark based on a fuzzy neural network technique. The system is modelled by trainable fuzzy inference rules with several input variables (qualitative and quantitative design components of CI symbol mark) and a single output variable (consumer's feeling). The back propagation learning algorithm, which is a conventional learning method of multilayer feedforward neural networks, is used for parameter identification of the fuzzy inference system. The learning ability to train data and the generalization ability to test data are evaluated for the proposed evaluation system by computer simulations.

• Communications for Statistical Applications and Methods
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• v.10 no.3
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• pp.919-930
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• 2003

Mark-Recapture method for open population commonly use Jolly-Seber method. This method assumes that all animals are equally likely to be caught in each sample (the equal catchability). This objects are making introduction of Mark-Recapture method for open population and using the robust design that combine a open population method with close population method to solve upper problems. Then population growth rate estimators that are derived Pollock's Jolly-Seber parameters and Kendall's Jolly-Seber parameters are estimated.

• Nuclear Engineering and Technology
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• v.11 no.1
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• pp.21-27
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• 1979

The relative reaction rates were measured in the TRIGA Mark II reactor core and analyzed to obtain the neutron spectrum parameters; relative neutron temperature T$^{n}$ and epithermal index (equation omitted) Measurements were made with the central thimble and the F2 position containing the light water. The relative neutron temperature was represented by the activation ratio of Lu-Mn, and the epithermal index was measured by Au-Mn foil activation. The multichannel analyzer was used to measure the relative ${\gamma}$-rays of the detector foils. The results were compared with the calculated values.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.150.5-150
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• 2001

This paper deals with a modified repetitive control method for compensating automatic gauge control (AGC) to reduce the effect of skid mark which directly influence the quality of products in plate mill process. Since the skid mark on the plate have thermal difference, it makes a different stretching rate and deflection of thickness. Firstly, the (AGC) system and the plate mill process are described by considering function in each control levels. The skid mark of the plate in practical control fields is shown. Also, its frequency variation is given by on-line FFT analysis method. Secondly, a key idea of the modified repetitive control method with time varying period disturbance is represented and compared with standard repetitive control method. Lastly, in simulation ...

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.6
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• pp.1483-1495
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• 1994

A quantitative analysis of a surface roughness for a precision machining of a sculptured surface in milling process is treated under superposition theory in this paper. The geometrical surface rouhgness is calculated as a function of feed per tooth, path interval, radii of tool and cutting edge, and radii of curvatures of workiece. Through machining experiments in a 3-axis machining center, we confirmed the adequacy of the adequacy of the analysis. While cutter mark is neglegible in ball endmilling, it is significant in flat endmilling. When feed per tooth is very small, flat endmilling gives superior finish to ball endmilling. In flat endmilling, cutting condition and cutter path should be strategically chosen to balance the cutter mark height and cusp height.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1994.04a
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• pp.42-48
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• 1994

This paper presents the navigation method for a mobile robot which uses a single camera and fluorescent lamp as a guide mark, projected on a convex mirror. The current position and heading direction of the mobile robot are obtained from the image of the guide mark. While the mobile robot travels to a goal position, the current position and heading direction of the mobile robot are updated continuously and the desired path and actual moving path are displayed on the monitor screen in real time. This proposed method eliminates the need to rotate the camera to track the guide mark, since a panoramic view of the surrounding area is available from the convex mirror, and natural guide marks such as usual florescent lamp on the ceiling or door frame can be used for navigation.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.11
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• pp.77-84
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• 2009

Alignment error of the BGA lithography equipment is mainly caused by the dimensional change of the BGA panel which is generated during the manufacturing processes. To minimize the alignment error, 'mark alignment' algorithm in place of 'center alignment' algorithm was proposed and the optimal solution for the algorithm was derived by simple analytic form. The developed algorithm distributes evenly the alignment error over the whole panel which was evaluated by the numerical simulation. Finally, the developed algorithm was implemented to the controller of the lithography equipment and the alignment error was measured at the fiducial mark location. From the measurement, it is also concluded that the developed alignment algorithm be effective to reduce the maximum value of alignment error.