• 치과방사선
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• 제12권1호
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• pp.115-121
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• 1982

In the study of the focal trough of panoramic radiograph, using the Moritta compony Panex-EC a series of 48 exposures were: taken with the 6-18 brass pins placed in the holes of the plastic model plate, then eveluated by 4 observers. The author analyzed the focal trough defined by the sharpness criteria and calcuated the vertical and horizontal magnification range in the corrected focal trough. The results were as follows; 1. Continuous focal trough was not defined in the anterior region using a very high degree of sharpness. 2. As degree of sharpness used in the analysis became less, focal trough was continuous in the anterior and posterior regions, symmetrized bilaterally, and the widths of the focal trough increased more in the posterior region. e. As sharpness criteria were reduced, the percentage range of image magnification increased on both vertical and horizontal magnification, and especially the percentage range of horizontal magnification was greater than that of vertical magnification.

• 대한족부족관절학회지
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• 제19권4호
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• pp.197-200
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• 2015

The Akin osteotomy is a complimentary procedure in hallux valgus surgery. Surgical techniques may vary depending on the operators or fixation devices. Suture fixation, for which a removal procedure is not necessary, can often be recommended. However, there is a risk of failure due to the thin cortex of the phalanx. We describe a new technique using Ethibond suture fixation in Akin osteotomy, which can lower the risk of phalangeal cortical failure and articular cartilage irritation. First, the Akin osteotomy was performed on the proximal phalanx 5 to 6 mm distal to the first metatarsophalangeal joint. Then bone holes were drilled from dorsum to plantar parallel to osteotomy with the Kirschner wire. The final procedure involved passing the Ethibond sutures connected to a straight needle through the holes and tying it. This fixation method offers an effective and easy technique for performance of Akin osteotomy.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(4)
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• pp.65-68
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• 2002

In an automatic fingerprint recognition system, a thinning process after binarization is commonly used. However it gives rise to spurs and holes often causing many spurious minutiae. Thus, more elaborate postprocessing is urgently needed to remove such spurious minutiae. To overcome this problem, we present a method of extracting minutiae based on horizontal and vertical run-length encoding from a binary fingerprint image without thinning process. Experimental results show that the proposed method for extracting minutiae is fairly reliable and fast, when il is compared to other method adopting a thinning process.

• 치과방사선
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• 제20권1호
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• pp.71-78
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• 1990

저자는 Panelipse Ⅱ의 상층 및 상의 확대변화를 관찰하기 위하여 모형판에 금속구를 위치시켜 3가지 Profile Index에서 각기 20장씩 방사선사진을 촬영하여 관찰한 결과를 다음과 같이 요약할 수 있었다. Profile Index의 증가에 따른 Panelipse Ⅱ 방사선상의 상층에 있어 모양의 변화는 없었고, 폭은 더 넓어졌으며, 회전축중심에서 외측으로 상층은 이동하였다. 방사선상에서 수평 수직확대는 공히 Profile Index가 증가함에 따라 그 범위가 커졌으며 이는 수평확대에 있어 수직확대보다 현저하였다.

• 한국조경학회지
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• 제21권1호
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• pp.13-30
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• 1993

The purpose of this study was to present data to the landscape planning and design through analyzing correlation between visual preference of users and nonusers and the landscape of hole in golf couses. Stimulus objects were selected from the 18 holes in Tae-gu Country Club. Preference value was judged through photo simulation by 35 subjects photographed at Tee and Interpoint (IPI, IP2), and classified into three landscape types and nine landscape components from photo analysis by researcher. For test of difference between groups toward each stimulus, t-test was used, and Duncantest, Correlation analysis for finding out correlation between preference degree and the landscape of each hole. The results of this study were as follows: As a result of analysis of preference value between groups for each hole, it has been shown that there was scarcely difference with each other. Form the relation between preference degree and spacial structure of hole, the holes making up a superior preference group have been shown that the greater part of the holes had a downward slope or a gentle slope mostly and then a visible ratio of fairway was high, and had diversified scenery by a lotus pond, a solitary planting tree, the roll of a fairway, facilities for convenience, etc. The holes making up a low-ranking preference group have been shown that the greater part of the holes had upward slope or a similar slope to it and had characteries of the bad condition of lawn, the nearby factories and odors, the monotonous scenery of a fairway, an unreasonable mixing of holes, etc. From the relation between preference degree and landscape components forming hole, it has been shown that the preference degree between users and nonusers had positive correlation to the occupied ratio of space of landscape components at Tee and Approach. At Tee, it has been shown that the preference degree of two groups were related with a lawn surface of fairway negatively, a lotus pond, a sky positively, and the preference degree of nonusers was related with iron-top for electric transmission positively. At Approach, it has been shown that the preference degree of two groups were related with iron-top for electric transmission negatively, and the preference degree of nonusers was related with a building positively. From the relation between preference degree group to each hole and the occupied ratio of space of landscape types, it has been shown that the constituent ratio of a high-ranking group was 1:2.4:2.2 and a low-ranking group was 1:4.1:5.1 among vertical type, horizontal type and background at Tee, but the constituent ratio of space of a high-ranking group was similar to a low-ranking group at Approach.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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• pp.929-934
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• 2002

Eight full-scale columns were constructed and tested under monotonic axial compression loading to investigate the influence of headed bars on the confinement of the concrete. One column represented a column with no transverse reinforcement and another column had poor detailing and little confinement. A third column contained seismic hoops and crossties, which represented current detailing practice for significant confinement. A fourth column test is conducted to investigate the response with the seismic crossties replaced by headed bars. Two column specimens were constructed and tested with all of the transverse reinforcement provided by headed bars. These six specimens enabled an assesment of the effectiveness of headed bars in confining the concrete. It was found that the use of headed bars improved the confinement of the columns. Two additional specimens were constructed without any transverse reinforcement. These columns were later retrofitted, by drilling horizontal holes in the columns, adding special headed bars (one head fixed and the other head threaded) and then filling the drilled holes with epoxy. These retrofitted specimens with these added headed bars provided insight into the rehabilitation of older structures containing poorly detailed columns. All of the test specimens were instrumented to determine strain localization during failure and to monitor the strain in the longitudinal and transverse reinforcement.

• 천문학회보
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• 제39권2호
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• pp.74.1-74.1
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• 2014

We study a wraping instability of a geometrically thin, non-self-gravitating disk surrounding binary supermassive black holes on a circular orbit. Such a circumbinay disk is subject to not only tidal torques due Line 8 to the binary gravitational potential but also radiative rorques due to radiation emitted from each accretion disk. We find tat a circumbinary disk initially aligned with the binary orbital plane is unstable to radiation-driven warping beyond the marginally stable warping radius, which is sensitive to both the ratio of vertical to horizontal shear viscosities and the mass-to-energy conversion efficiency. As expected, the tidal torques give no contribution to the growth of warping modes but tend to align the circumbinary disk with the orbital plane. Since the tidal torques can suppress the warping modes in the inner part of circumbinary disk, the circumbinaary disk starts to be warped at the radii larger than the marginally stable warping radius. If the warping radius is of the order of 0.1 pc, a resultant semi-major axis is estimated to be of the order of 10-2 pc to 10-4 pc for 107 Msun black hole. We also discuss the posibility that the central objects of observed warped maser disks in active galactic nuclei are binary supermassive black holes with a triple disk: two accretion disks around the individual black holes and one circumbinary disk surrounding them.

• 마이크로전자및패키징학회지
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• 제13권4호
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• pp.45-50
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• 2006

3D package의 SiP에서 구리의 via filling은 매우 중요한 사항으로 package밀도가 높아짐에 따라 via의 크기가 줄어들며 전기도금법을 이용한 via filling이 연구되어왔다. Via filling시 via 내부에 결함이 발생하기 쉬운데 전해액 내에 억제제, 가속제등 첨가제를 첨가하고 펄스-역펄스(PRC)의 전류파형을 인가하여 결함이 없는 via의 filling이 가능하다. 본 연구에서는 건식 식각 방법 중 하나인 DRIE법을 이용하여 깊이 $100{\sim}190\;{\mu}m$, 직경이 각각 $50{\mu}m,\;20{\mu}m$인 2가지 형태의 via을 형성하였다. DRIE로 via가 형성된 Si wafer위에 IMP System으로 Cu의 Si으로 확산을 막기 위한 Ta층과 전해도금의 씨앗층인 Cu층을 형성하였다. Via시편은 직류, 펄스-역펄스의 전류 파형과 억제제, 가속제, 억제제의 첨가제를 모두 사용하여 filling을 시도하였고, 공정 후 via의 단면을 경면 가공하여 SEM으로 관찰하였다.

• Journal of the Optical Society of Korea
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• 제13권4호
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• pp.428-433
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• 2009

A photonic crystal fiber with two large air holes outside the holey cladding region is fabricated to induce an effective long periodic grating (LPG) in the core by an electric arc discharge. We believe that the two large air holes lead to the asymmetric perturbation in the core under the electric arc discharge, thereby introducing the coupling to the first higher-order mode. The transmission characteristics of the PCF with the LPG for the external perturbation such as strain, curvature, and temperature are also investigated. It was found that the shift of resonance peak in the transmission spectrum depends on the bending direction. The curvature of 8.55 $m^{-1}$ results in the center wavelength shifts of 1.8, 4.3, and 11 nm for a vertical, diagonal, and horizontal direction of the curvature to the large air-hole alignment, respectively.

• 한국지반공학회논문집
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• 제21권5호
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• pp.133-142
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• 2005

본 연구는 지난 5년간 개발해온 인홀 발진자를 터널 막장의 강성도 계측에 사용가능하도록 개선하는데 주력하였다. 프로브는 터널의 폭파를 위해 점보드릴로써 천공된 직경 45m의 홀에 맞추기 위하여 소형화되었다. 또한 트리거 시스템은 감속모터를 사용함으로서 편리하게 되었고, 에어 팩킹 시스템은 압축공기 없이 사용하기위한 플레이트 스프링으로 교체하였다. 이러한 개선은 프로브를 터널내부의 환경에 적합하게 만들고 추가되는 비용 없이 실험하기 위함이다. 프로브와 테스트 과정은 암반의 강성을 측정하기 위해 터널의 막장의 수평 홀에 성공적으로 적용되었다. 측정된 전단파 속도는 터널 해석을 위한 암반의 변형 특성을 측정하는 것에 사용될 수 있다.