• 전자공학회논문지B
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• 제33B권2호
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• pp.56-64
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• 1996

In the previous paper of this study, an incoherent intensity pattern of a conducting cylinder is obtained by averaging out the multi-frequency intensities of the time-harmonic fields scattered from this cylinder. in this paper, an incoherent imaging of a conducting cylinder is obtained via the back-projection of the incoherent intensity patterns calculated from the circular rotational measurement configuration. This imaging method is vlaidated by imaging a conducting circular and a conducting elliptic cylinder and the measurement conditions to get better image are investigated.

• Interaction and multiscale mechanics
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• 제6권2호
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• pp.211-235
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• 2013

An incompressible smoothed particle hydrodynamics (ISPH) method based on the incremental pressure projection method is developed in this study. The Rayleigh-B$\acute{e}$nard convection in a square enclosure is used as a validation case and the results obtained by the proposed ISPH model are compared to the benchmark solutions. The comparison shows that the established ISPH method has a good performance in terms of accuracy. Subsequently, the proposed ISPH method is employed to simulate natural convection from a heated cylinder in a square enclosure. It shows that the predictions obtained by the ISPH method are in good agreements with the results obtained by previous studies using alternative numerical methods. A rotating and heated cylinder is also considered to study the effect of the rotation on the heat transfer process in the enclosure space. The numerical results show that for a square enclosure at, the addition of kinetic energy in the form of rotation does not enhance the heat transfer process. The method is also applied to simulate forced convection from a circular cylinder in an unbounded uniform flow. In terms of results, it turns out that the proposed ISPH model is capable to simulate heat transfer problems with the complex and moving boundaries.

• 전자공학회논문지D
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• 제35D권1호
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• pp.1-7
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• 1998

In this paper, an incoherent imaging of a conducting cylinder illuminated by the single-frequency time-harmonic plane wave is obtained via the back-projections of the intensity patterns of the forward total electric field scattered from this object in the circular rotational measurement configuration. The pheonmenon that interference fringes generated in the itesity patterns is removed in the back-projection process is interpreted numerically. This imaging method is validated by imagining conducting circular cylinders and the conditions to ge beter image are investigated.

• 전자공학회논문지A
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• 제29A권2호
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• pp.1-7
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• 1992

A consideration for image improvement under the Born approximation in the microwave diffraction tomography is suggested by using a projection function. The limiting factors in the degrading reconstructed image due to Born approximation are identified in terms of projection function and its modification is suggested to improve the degraded image based upon the Born approximation. In order to verify the proposed method, the reconstructed images are shown by computer simulation from the back-scattered data of angular and frequency diversity for squared dielectric cylinder with a various relative dielectric constant. From simulation results, it was shown that the proposed method can lead to a fairly good improved image for a severe degraded one irrespective of homogeneous and inhomogeneous dielectric object. In the future, the analysis on the limitation of this method should be considered and performed by means of more quantitative method.

• 한국자동차공학회논문집
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• 제7권8호
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• pp.99-106
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• 1999

The present study deals with the effect of combustion chamber shape on in-cylinder soot oxidation characteristics of a D.I . diesel engine. The analysed combustion chambers were a toroidal and a reentrant with a projection(Complex). The two-color method was used to measure in-cylinder flame temperature and KL value which is approximately proportional to the soot amount along the optical path. In addition, heat release rate was calculated from the in-cylinder pressure data. From these investigations , the soot oxidation of the reentrant and the complex which were strengthen squish flows went worse in late combustion period under heavy-load operation compared to that of the toroidal at retarded fuel injection timing . It might be the cause of the flame holding that squish lip depress the outflow of flame from the bowl to the entire combustion space.

• Archives of Plastic Surgery
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• 제41권2호
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• pp.158-162
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• 2014

Background Loss of nipple projection is a common problem following nipple reconstruction. The aim of this study was to demonstrate that the use of a tightly rolled dermal graft is effective in the long-term maintenance of nipple projection. Methods Nipple reconstruction was performed using the C-V flap technique. A dermal graft was harvested from the dog-ear portion of previous scars. The graft was rolled tightly into a compact cylinder and used to augment the nipple reconstruction. Postoperatively, stacked Allevyn dressing was used for protecting the nipple from compression for a minimum of two months. Nipple projection was measured at the time of surgery and at 12 months postoperatively. Results Forty nipple reconstructions were performed using this technique. There were 19 transverse rectus abdominis musculocutaneous (TRAM) flaps, 10 latissimus dorsi (LD) flaps, and 11 tissue-expanded breast mounds. At one year, the mean projection was 0.80 cm (range, 0.62-1.22 cm). The twelve-month average maintenance of nipple projection was 70.2% for the TRAM flap group, 76.3% for the LD flap group, and 61.8% for the tissue-expanded group. In two patients with previous irradiation of the reconstructed breasts, relatively poor maintenance of nipple projection was noted (45.7%). No complications were noted, and all of the donor sites healed well primarily. Conclusions Our results demonstrated that the use of a C-V flap with a tightly rolled dermal graft for nipple reconstruction improves the long-term maintenance of nipple projection. Its advantages include reproducibility, technical simplicity, cost-effectiveness, and minimal donor site morbidity.

• 대한기계학회논문집
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• 제10권3호
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• pp.305-315
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• 1986

본 연구에서는 가변 기통 엔진의 동특성을 규명하기 위해 세곳으로 지지되는 직렬 4기통 디이젤 엔진에 대한 3자유도 모델을 설정하였고, 이 모델에서 각 마운트의 위치와 경사각 및 방진고무의 크기를 변경시킬 때의 최적화 문제를 컴퓨터 시뮬레이션 으로 고찰하였다.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2010년도 춘계학술발표대회 초록집
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• pp.48-48
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• 2010

소형 공조장치용 냉매 압축기 부품인 기계식 제어 밸브는 에어컨 컴프레서의 핵심부품이고 년간 수백만 개가 국내에 수입된다. 이를 국산화 하기 위하여 진공로 속에서의 브레이징 공정이 수반되는 외국제품의 제조공정을 탈피하여 진공 속에서 DC 프로젝션 용접을 수행하는 기법을 개발하였다. 실린더 형상의 캡과 케이스를 맞대고 그 사이에 박판을 삽입한 상태에서 butt welding 방식으로 진행되는 본 공정에서는, 생산성이 높고 서보가압 장치를 사용하여 soft touch 를 구현하므로 프로젝션이 손상되지 않은 상태에서 통전이 시작되고 2 단 가압 및 프로파일 가압이 가능하므로 링(ring)형상의 너깃이 축대칭으로 안정적으로 형성되기 때문에 실린더 내부의 밀봉성능이 우수함을 확인하였다. 진공로 속에서 본 가압장치를 설치하여 간편한 방법으로 실린더 내부의 진공상태를 유지할 수 있기 때문에 진공로 속에서의 브레이징 공정이 적용되는 외국제품보다 생산성이 월등함을 알 수 있다. 본 연구에서 개발된 링 프로젝션(ring projection) 용접기법은 초소형 및 소형 실린더 형상의 부품 내부를 진공으로 유지해야 하는 산업현장에서 당장 적용될 수 있는 혁신적인 용접공정이라 판단된다.

• Applied Microscopy
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• 제27권2호
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• pp.111-120
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• 1997

Cylinder-like crystals of $Ca^{2+}-ATPase$ provide views parallel to the lamellar plane, from which parameters of lamellar stacking can be directly measured. These parameters were measured using different preparation methods. Assuming that molecular packing is the same, data from lamellar plane could supplement those obtained by tilting large, thin plate-like crystals. However, base on data obtained .by electron microscopy and x-ray powder patterns, the plate-like crystal may have another scheme for stacking the lamellar. The projection map (h, 0, 1) from cylinder-like crystals using cryoelectron microscopy suggest the lamellar spacing can be variable.

• 한국콘텐츠학회논문지
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• 제9권4호
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• pp.34-44
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• 2009

여러 시점에서 계측한 3차원 데이터의 통합은 3차원 모델링에 매우 중요한 기술이다. 기존의 표면통합 방법은 잡음에 민감하고 표면을 구성하는 정점들을 수정하기 때문에 응용에 따라 적합하지 않다. 본 논문에서는 표면의 지역적 지형을 이용하는 표면통합 방법을 제안한다. 제안하는 방법은 먼저 인접한 표면사이에서 일정 지형적 조건을 만족하는 외곽 정점의 쌍 즉, 대응정점들을 찾는다. 모든 대응정점들을 찾은 후 각 대응정점 별로 해당지역에 적합한 2차원평면을 구하여 대응정점과 그 주변 외곽정점들을 투영한다. 투영된 정점들을 연결하여 얻은 다각형을 삼각형 단위로 분할하여 인접한 표면 사이에 삽입함으로써 표면을 통합한다. 제안하는 방법은 지역적 지형을 이용하기 때문에 강건하고 표면의 정점을 수정하지 않기 때문에 간단하다. 본 논문에서는 또한 질감통합을 위해 원통투영(cylinder projection)을 통해 얻은 질감영상들을 얼굴 객체의 특성을 고려하여 구한 구분선을 따라 통합한다. 제안하는 질감통합 방법은 빠르다는 장점을 갖는다. 실세계 얼굴 객체에 대한 실험과 기존방법과의 비교를 통해 제안하는 방법의 간단함과 강건성을 보인다.