• 한국도로학회:학술대회논문집
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• 한국도로학회 2010년 추계학술대회 논문집
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• pp.265-270
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• 2010

• 한국ITS학회:학술대회논문집
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• 한국ITS학회 2004년도 제3회 정기총회 및 추계학술대회
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• pp.111-114
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• 2004

• Tribology and Lubricants
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• 제16권2호
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• pp.133-137
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• 2000

A new method to calculate the wear amount using surface profile signal was suggested. It takes advantage of filtering technic to estimate the original surface profile of wear track precisely. The original profile of wear track was estimated by comparing with outside of wear track. The estimated surface profile was well fitted to the original profile assumed unknown.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1999년도 제30회 추계학술대회
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• pp.200-207
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• 1999

A new method for the calculation of a wear amount was suggested. The amount of wear was calculated by the comparison of worn out profile with an estimated original profile. An original profile of wear track was estimated by comparing with outside of wear track. An estimated surface profile was well fitted to the original profile assumed unknown.

• 대한족부족관절학회지
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• 제21권1호
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• pp.7-11
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• 2017

Purpose: We retrospectively analyzed the radiographic and clinical results after the first ray of forefoot osteotomy using low profile wedge plate without additional cancellous bone grafting for pes planus correction. Materials and Methods: Twenty-four patients were enrolled in this study. Medial cuneiform opening wedge osteotomy was performed in 12 patients (Cotton osteotomy, group C) and first metatarsal base osteotomy was performed in 12 patients (group MT). Results: On average, the wedge size was 5.61 mm (5~6 mm). The mean time to radiographic union was 3.18 and 3.27 months in groups C and MT, respectively. Postoperative talonavicular coverage angle, talo-first metatarsal angle (anteroposterior), talo-first metatarsal angle (lateral), talo-calcaneal angle (lateral), medial cuneiform height, and American orthopaedic foot, as well as ankle society midfoot scale were significantly improved in both groups. Nonunion, delayed union or fixation failure was not presented in our series. Conclusion: We have shown that low profile wedge plate was effective in the case of first ray forefoot osteotomy for pes planus correction without any additional cancellous bone grafting.

• 한국전자파학회논문지
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• 제13권7호
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• pp.709-715
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• 2002

본 연구에서는 직접적인 급전방식인 마이크로스트립 급전과 H-shaped 개구 결합 급전을 이용해 마이크로스트립 안테나에서 최대 송수신간 전력간섭을 억제하여 송수신 분리 구현이 가능한 높은 격리도 특성을 가지면서도 최소의 기판 층 사용 및 쉬운 급전을 할 수 있는 새로운 구조의 이중급전 이중편파 안테나를 제시하고 실험을 통한 타당성을 보였다. 제안된 단일 안테나와 1$\times$4 배열 안테나의 측정된 격리도는 -49 dB와 -48 dB이하의 특성을 가졌고, 측정된 임피던스 대역폭(VSWR<1.5)은 중심 주파수 12.5 GHz에서 4 %, 중심 주파수 14.25 GHz에서 2.1 %를 보였으며, 최대 이득은 8.25 dBi와 14.2 dBi로 측정되었다.

• 제어로봇시스템학회논문지
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• 제18권12호
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• pp.1079-1085
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• 2012

For precise motion control, S-curve velocity profile is generally used but it has disadvantage of relatively long calculation time for floating-point arithmetics. In this paper, we present a new generating method for velocity profile to reduce delay time of profile generation so that it overcomes such disadvantage and enhances the efficiency of precise motion control. In this approach, the velocity profile is designed based on the gamma correction expression that is generally used in image processing to obtain a smoother movement without any critical jerk. The proposed velocity profile is designed to support both T-curve and S-curve velocity profile. It can generate precise profile by adding an offset to the velocity profile with decimals under floating point that are not counted during gamma correction arithmetic operation. As a result, the operation time is saved and the efficiency is improved. The proposed method is compared with the existing method that generates velocity profile using ring buffer on a 8-bit low-cost MCU. The result shows that the proposed method has no delay in generating driving profile with good accuracy of each cycle velocity. The significance of the proposed method lies in reduction of the operation time without degrading the motion accuracy. Generated driving signal also shows to verify effectiveness of the proposed method.

• Journal of Chest Surgery
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• 제25권8호
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• pp.863-870
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• 1992

The low profile Ionescu-Shiley pericardial xenograft valve had been initially introduced to have improved hemodynamic performance and expected superior durability, However, subsequent clinical reports and laboratory studies have repeatedly indicated early failure of the valve from mechanical reasons in valve design, A total and consecutive 169 patients underwent isolated MVR with the low profile Ionescu-Shiley valve at Seoul National University Hospital from November 1984 to October 1989 [Group ISLM]. Five patients [3.0%] died within 30 days of surgery, and early survivors were followed up for 734.9 patient-years [Mean$\pm$SD, 4.9$\pm$2.0 years], Late mortality rate was 0.136% /patient-year [pt-yr], Linearized incidences of major complications were: 0.953% embolism /pt-yr; 0.680% bleeding /pt-yr; 0.272% endocarditis /pt-yr; and 0, 408% primary tissue failure [PTF] /pt-yr, The actuarial survival was 99.4$\pm$0.6%, and probabilities of from thromboembolism and from PTF were 90.7$\pm$4.6% and 95.9$\pm$2.6% at 8 years, respectively These results were compared with the clinical data from the 291 patients of isolated MVR with the standard Ionescu-Shiley valve at the same hospital during the period between October 1978 and June 1983 [Group ISUM], Group ISUM included 11% of patients younger than 15 years of age, whereas Group ISLM did no patient of this age. The mean age at the time of surgery was significantly younger in Group ISUM than one in Group ISLM [P<0.001]. Differences were not statistically significant in operative mortality, mean follow-up period and linearized incidences of thromboembolism, bleeding and endocarditis, between two groups, However, the linearized rate of PTF was lower [P<0.001] and probabilities of freedom fro PTF higher [P<0.001] in Group ISLM at least up to postoperative 8 years. While the features of PTF of the standard valve was predominantly degeneration with calcification and stenosis, the ones of the low profile valve was cusp tear and incompetence. It remains, however, to be seen whether the low profile valve fails mostly from mechanical reason, and further follow-up will still be necessary to determine the differences in mode of PTF of two valves.

• 한국전자파학회논문지
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• 제25권1호
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• pp.25-31
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• 2014

본 논문에서는 인체 내 외부간 근거리 통신망인 WBAN(Wireless Body Area Network)에서 인체 부착형 기기간 통신링크를 원활하게 구성하기 위한 변형된 Alford 안테나를 제안하였다. 제안된 안테나는 인체의 영향을 고려해 설계하였으며, ISM(The Industrial, Scientific and Medical, 2.4~2.485 GHz) 대역에서 동작한다. 기존 Alford 루프 안테나는 low-profile인 장점이 있지만, 인체 부착용 시스템의 다른 부품을 설치할 접지면이 존재하지 않고 balanced 급전 구조를 사용하기 때문에 on-body 안테나로 적합하지 않다. 따라서 본 논문에서는 on-body 환경에서 동작할 수 있는 접지면이 포함된 unbalanced 급전 구조를 갖는 안테나를 제안하였다. 또한, 안테나가 인체에 부착되어 안테나 성능에 미치는 영향을 고려하기 위해 모의 인체를 통해 모의실험과 측정을 수행하였다. 제안된 안테나는 모노폴 형태의 방사 패턴을 갖는 low-profile 구조이며, ISM 대역 내에서 10 dB 반사 손실을 만족한다. 안테나는 on-body 통신 환경에 적합한 표면지향성 특성을 갖는다.

• 접착 및 계면
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• 제12권4호
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• pp.144-150
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• 2011

폴리스티렌을 저수축제로 사용하고 Zn-stearate를 이형제로 사용하여 함량변화에 따라 벌크 몰드컴파운드의 표면형태 및 기계적 물성에 미치는 영향을 고찰하였다. XPS, 접촉각 측정기 등을 이용하여 표면과 깊이 방향에 대한 원소함량과 접촉각을 측정하였고, 표면형태는 FESEM을 이용하여 관찰하였으며, 표면조도 측정은 AFM을 이용하였다. 저수축제를 첨가하지 않은 경우에 비교하여 저수축제를 9.0 wt% 첨가하였을 경우에는 체적수축률은 0.35%에서 0.05%로 감소하였으며, 표면조도는 $0.27{\mu}m$에서 $0.12{\mu}m$로 감소하였다. 이형제의 함량을 1.8 wt%에서 3.6 wt%로 증가시켰을 경우에는 이형제가 주로 표면에 존재하고 표면조도를 증가시키는 것을 확인하였다. 저수축제의 함량을 5.0 wt%에서 9.0 wt%로 증가시킴에 따라 굴곡탄성율과 충격강도가 약 30% 감소하였다.