• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 춘계학술대회 논문집
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• pp.739-742
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• 2000

From the experimental study of W-EDM for alloyed steel, the characteristics such as Hand Drum Form and surface roughness have been observed and evaluated for various conditions. In square hole, the increase of If as to made condition the calculate high value of surface roughness. Also compare dimensionless square hole with circle hole' graph. In circle hole, if a value of surface roughness IP 6 in a side of circle it show a 0.4${\mu}{\textrm}{m}$ and in IP 8, 0.6${\mu}{\textrm}{m}$, in IP 10, 0.7${\mu}{\textrm}{m}$, in IP 12. 0.8${\mu}{\textrm}{m}$ higher than before. This figure show the surface roughness is higher than before, because a table move in either X-axis or Y-axis in square hole, on the contrary, in circle there table move in X-axis and Y-axis at the same time. hand drum form getting small when wire tension increase 1000gf to 1500gf, at the same working conditions. the smaller of off time, the mailer of hand drum form in same condition and same wire tension. but if you compare square hole with circle hole' graph hand drum form displayed in maintained term of working condision, on the contrary, in case of square hole variation of hand drum form is more increase than a grow of IP

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 춘계학술대회논문집 - 한국공작기계학회
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• pp.567-572
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• 2000

From the experimental study of W-EDM for alloyed steel, the characteristics such as Hand Drum Form and surface roughness have been observed and evaluated for various conditions. In square hole, the increase of IP as to made condition, the calculate high value of surface roughness. Also compare dimensionless square hole with circle hole' graph, In circle hole, if a value of surface roughness IP 6 in a side of circle it show a 0.4${\mu}{\textrm}{m}$ and in IP 8, 0.6${\mu}{\textrm}{m}$, in IP 10, 0.7${\mu}{\textrm}{m}$, in IP 12, 0.8${\mu}{\textrm}{m}$ higher than before. This figure show the surface roughness is higher than before, because a table move in either X-axis or Y-axis in square hole, on the contrary, in circle there table move in X-axis and Y-axis at the same time. hand drum form getting small when wire tension increase 1000gf to 1500gf, at the same working conditions. The smaller of off time, the maller of hand drum form in same condition and same wire tension. but if you compare square hole with circle hole' graph, hand drum form displayed in maintained term of working condision, on the contrary, in case of square hole variation of hand drum form is more increase than a grow of IP

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 하계종합학술대회논문집
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• pp.721-724
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• 1998

A circular image in a space don't appear as an exact circular image and appear as an oval in image buffer because distortion of camera lens, number of horizontal pixel of CCD photographing element and unmber of horizontal pixel of image buffer are not in accordance. By using familiar 3-D coordinate, know as circle's diameter, and cicle's center, you correct a pin-hole camera and get an exact circle with reprojection a circle into image buffer, according to a perspective.

• 한국진공학회지
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• 제12권4호
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• pp.288-292
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• 2003

Air hole 구조를 갖는 2차원 고분자 광결정 도파로를 나노 임프린트 방법으로 제작하기 위하여, e-beam lithography와 ICP etching 공정을 이용하여 기둥 구조를 갖는 실리콘 나노 마스터를 제작하였다. Air hole 구조를 갖는 광결정 구조를 얻기 위해, 실리콘 마스터 기둥의 형태를 4각형, 6각형, 12각형 및 원으로 설계하였다. 제작된 기둥의 직경과 구조를 CD-SEM과 SPM-AFM을 이용하여 측정하였으며, dose가 432 $\mu$C/$\textrm{cm}^2$일 때 최적의 dose임을 확인하였다.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제8권1호
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• pp.81-92
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• 2004

Muskhelishvili's complex variable method has been applied to derive exact and closed expressions for Gaursat's functions for the first and second fundamental problems of the infinite plate weakened by a curvilinear hole which is conformally mapped on the domain outside the unit circle by means of rational mapping function. The hole having three poles. The previous work of the authers in this domain is considered as special cases of this work.

• Radiation Oncology Journal
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• 제7권2호
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• pp.299-303
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• 1989

Authors have developed highly reproducible calibration method for the Micro-Selectron HDR Ir-192 system (Nucletron, Motherland). The new jig has a 10cm radius circular hole in the $30cm{\times}30cm{\times}0.2cm$ acrylic plate, and 5F flexible bronchial tubes are attached around the hole. The source moves along the circle in the tubes and the ionization chamber is placed verticaly at the center of the circular hole (center of the jig). Dose distribution near the center was derived theoretically, and measured with the film dosimetry system. Theoretical calculation and measurement show the error margin below $0.1\%$ for 1mm or 2mm position deviation. We have measured at 12 and 24 points of circle with 1, 6, 11 and 21 second dwell time of source in order to calculate the activity of the source. Measurements have been repeated daily for 50 days. The accuracy and the reproducibility are below $1\%$ error margin. The half life of the source from our measurement is estimated $73.4\pm0.4$ days.

• 한국기계가공학회지
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• 제16권5호
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• pp.126-133
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• 2017

This report investigates the stress distribution according to the location and shape change of the circular hole for the lightweight design of the cross beam of a railway passenger car and studies the lightweight design. To design a lightweight cross beam with a circular hole, we selected the non-circular crossbeam as a basic model, examined the stress distribution and displacement by position and determined the location, shape, size and quantity of the hole for light weight. We analyzed the effects of the position and shape of the hole on the maximum equivalent stress and displacement. The influencing factors were set as the design parameters, and the stress value was examined according to the variation of each variable. By considering the stress value according to the change of each variable and selecting the design parameter with the narrowest scattering value of the stress at each position of the hollow cross beam with various hole positions and shapes, we studied a cross beam with a circle hole under identical load condition to have an equal stress distribution to that of a non-circular cross beam.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2007년 추계학술발표대회 개요집
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• pp.218-221
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• 2007

The surface mounting technology of 0402 electric chip part is necessary to fabricate a high density and multi-functional module, but there is a limitation of the technology, like as a bridge and self-alignement. This work estimated SMT processing factors of 0402 chip. To obtain optimum SMT process, we evaluated effects of stencil thickness, shape of hole on printability and mountability. Printability shows best results under the thickness of $80{mu}m$ with circle hole shape and 90% square hole shape. In case of chip mounting process, chip mis-alignment and bridge was occurred rarely in same conditions. In more thin stencil thickness, $50{mu}m$, strength of 1005 chip parts was poor, because of amount of printed solder was insufficient.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권3호
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• pp.1650-1669
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• 2017

In this study, each pixel in an ear is used as a centroid to generate a cake. Subsequently the major axis length of this cake is computed and obtained. This obtained major axis length serves as a feature to recognize an ear. Later, the ear hole is used as a centroid and a 16-circle template is generated to extract the major axis lengths of the ear. The 16-circle template extracted signals are used to recognize an ear. In the next step, a ring-to-line mapping technique is used to map these major axis lengths to several straight-line signals. Next, the complex plane vector computing technique is used to determine the similarity of these major axis lengths, whereby a solution to the image-rotating problem is achieved. The aforementioned extracted signals are also compared to the ones that are extracted from its neighboring pixels, whereby solving the image-shifting problem. The algorithm developed in this study can precisely identify an ear image by solving the image rotation and image shifting problems.

• 대한기계학회논문집A
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• 제36권2호
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• pp.195-201
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• 2012

다양한 소비자의 요구에 따라 가공된 제품을 좀더 신속하고 정확하게 측정할 수 있는 공작기계 내 자동계측장치를 적용하는 사례가 급격히 증가하고 있다. 자동 계측으로 가장 많이 활용되는 접촉식 측정 프로브는 주로 공작물의 가공 원점을 설정하고, 정확한 치수 검사를 통한 불량유무 판정 및 보상가공에 많이 활용된다. 따라서 본 연구에서는 기기상 자동계측장치인 접촉식 측정 프로브를 활용하여 가공된 형상을 신속하고 정확하게 측정하는 방법을 연구하였으며 이를 위하여 가장 많이 활용되는 홀 측정 사이클에 대한 매크로 프로그램을 개발하였다. 또한 측정 시 홀의 진원도 오차에 따라 발생할 수 있는 편심량을 시뮬레이션하여 분석하였으며 본 연구의 신뢰성을 높이기 위하여 기기상에서 개발된 홀 측정 매크로 프로그램을 이용하여 홀플레이트에 대한 측정이 이루어졌으며, 진원도 오차에 따른 편심량을 검증하였다.