Monte Carlo 시뮬레이션을 이용한 이온 주입시의 점결함 분포의 계산

손명식,이준하,변기량,황호정 중앙대학교 기술과학연구소 1995 기술과학연구소 논문집 Vol.25 No.-

이온 주입시의 점결함 분포를 간접적으로 계산하기 위해 단결정 실리콘에서의 3차원 이온 주입 시뮬레이터인 TRICSI (TRansport Ions in Crystal Slilicon) Monte Carlo 코드를 확장하여 Boron 이온 주입시의 에너지와 dose에 따른 불순물(particle) 및 점결함 분포(point defect)를 계산하였다. 결함 분포는 Modified Kinchin-Pease equation을 단결정 실리콘에 적용하여 displacement damage에 의해 발생한 Frenkel Pair(vacancy-interstitial)분포를 계산하였으며 이온 주입시의 웨이퍼 온도에 의한 Frenkel Pair 소멸 효과는 고려하지 않았다. 계산 결과는 3차원 각면으로의 2차원 투영 불순물 농도로 표현하고 주입된 dose와 에너지에 다른 마스크 주입시의 에너지 및 dose 의존성 도펀트 분포와 이에 따른 damage 분포를 이해하는 데 중요한 정보가 될 것으로 기대된다. We extended our ion implantation simulator, TRICSI (TRansport lons in Crystal Slilicon) Monte Carlo(MC) code, and indirectly calculated particle and its generating point defect distributions depending on energy and dose during boron implantation into <100> single0crystal silicon. The point defect distribution of Frenkel Pair(vacancy-interstitial) was abtained by applying the modified Kinchin-Pease equation, which usually uses in MC simulation in amorphous target, to MC simulation in crystalline silicon. We did not considered the annihilation of Frenkel Pairs due to wafer temperature. The calculated results were projected onto each free-dimensional plane, presented as two-dimensional concentration profile on it. The particle concentration profile was presented with typical open mask structure. We expect that these results help understand the dopant and its generating damage distributions depending on energy and dose during boron implantation.

완전대혈관 전위의 심방내 교정술 후 추적 관찰

김연우,노정일,허준,윤명자,김호성,최정연,윤용수,양세원,이정렬,김용진,노준량 대한순환기학회 1998 Korean Circulation Journal Vol.28 No.5

AN ITERATIVE ROW-ACTION METHOD FOR MULTICOMMODITY TRANSPORTATION PROBLEMS

Ryang, Yong Joon The Kangwon-Kyungki Mathematical Society 1996 한국수학논문집 Vol.4 No.1

The optimization problems with quadratic constraints often appear in various fields such as network flows and computer tomography. In this paper, we propose an algorithm for solving those problems and prove the convergence of the proposed algorithm.

A METHOD USING PARAMETRIC APPROACH WITH QUASINEWTON METHOD FOR CONSTRAINED OPTIMIZATION

Ryang, Yong-Joon,Kim, Won-Serk Korean Mathematical Society 1989 대한수학회보 Vol.26 No.2

This paper proposes a deformation method for solving practical nonlinear programming problems. Utilizing the nonlinear parametric programming technique with Quasi-Newton method [6,7], the method solves the problem by imbedding it into a suitable one-parameter family of problems. The approach discussed in this paper was originally developed with the aim of solving a system of structural optimization problems with frequently appears in various kind of engineering design. It is assumed that we have to solve more than one structural problem of the same type. It an optimal solution of one of these problems is available, then the optimal solutions of thel other problems can be easily obtained by using this known problem and its optimal solution as the initial problem of our parametric method. The method of nonlinear programming does not generally converge to the optimal solution from an arbitrary starting point if the initial estimate is not sufficiently close to the solution. On the other hand, the deformation method described in this paper is advantageous in that it is likely to obtain the optimal solution every if the initial point is not necessarily in a small neighborhood of the solution. the Jacobian matrix of the iteration formula has the special structural features [2, 3]. Sectioon 2 describes nonlinear parametric programming problem imbeded into a one-parameter family of problems. In Section 3 the iteration formulas for one-parameter are developed. Section 4 discusses parametric approach for Quasi-Newton method and gives algorithm for finding the optimal solution.

Optimal Policy for a Regional Water Distribution System

Ryang, Yong-Joon Military Operations Research Society of Korea 1985 한국국방경영분석학회지 Vol.11 No.1

This paper presents optimum policy of water supply distribution of the Osaka Prefecural Waterworks System located in the midwest of Japanese Islands. Owing to the ever increasing demand for water, the Osaka Prefectural Government endeavors to expand potable and industrial water distribution system to satisfy the growing water demand of the constituents under its jurisdiction. In this regard, the paper discusses a problem of establishing an efficient and effective water distribution system. The criteria to be considered are stability of water level at the reservoirs, stability of flow in the network, and the water treatment and distribution cost. These objective functions may be combined to form a multiple objective optimization problem or may be used independently and formulated into single objective optimization problems.

開心手術에 있어서 Epsilon의 術後 止血効果

盧浚亮(Joon Ryang Rho) 대한외과학회 1975 Annals of Surgical Treatment and Research Vol.17 No.2

Initial Growth of Nb on Cu(100) studied by STM and Density Functional Theory

Joon-Hee Lee,Kyung-Deuk Ryang,Chul-Woo Son,In-Whan Lyo,Jin-Ho Kang,Myung-Ho Kang 한국진공학회 2000 한국진공학회 학술발표회초록집 Vol.- No.-

Original Article : Effects of Multicurve RGP Contact Lens Use on Topographic Changes in Keratoconus

( Joon Seo Hwang ),( Jin Hak Lee ),( Won Ryang Wee ),( Mee Kum Kim ) 대한안과학회 2010 Korean Journal of Ophthalmology Vol.24 No.4

Purpose: To evaluate the effects of wearing rigid gas permeable (RGP) contact lenses on the topographic changes in keratoconus. Methods: Seventy-seven keratoconic eyes that wore multicurve RGP contact lenses and 30 keratoconic eyes that wore no contact lenses were retrospectively analyzed. The mean follow-ups were 22.6 and 20.5 months in the lens-wearing and control groups, respectively. Visual acuity, comfort, daily wearing time, and corneal staining were evaluated for both groups. The changes in topographic indices were compared between the lens-wearing and control groups. Results: Multicurve RGP lens corrected logarithm of the minimum angle of resolution visual acuity of the lens-wearing group significantly improved from -0.016±0.065 to -0.032±0.10 at follow-up (p=0.05). In the lens-wearing group with advanced keratoconus, the Sim Kmax, Sim Kmin, apical power, astigmatic index, and anterior elevation significantly decreased from 57.68±4.26 diopter (D), 50.50±2.32 D, 62.79±5.11 D, 7.20±0.55 D and 67.36±16.30 ㎛ to 55.51±4.28 D, 49.62±3.26 D, 60.31±5.41 D, 5.90±0.51 D and 60.61±16.09 ㎛, respectively (paired t-test, p<0.05). The irregularity index of 3 mm did not significantly change. Meanwhile, in the control group, the apical power and irregularity index increased from 55.56±7.25 D and 3.06±1.68 D to 57.11±7.75 D and 3.25±1.71 D, respectively (paired t-test, p=0.008, p=0.01). Conclusions: Properly fitted multicurve RGP contact lenses are not likely to contribute to the progression of keratoconus.

Molecular Investigation of Two Consecutive Nosocomial Clusters of Candida tropicalis Candiduria Using Pulsed-Field Gel Electrophoresis

Joon Rho,Jong Hee Shin,Jeong Won Song,Mi-Ra Park,Seung Jung Kee,Sook Jin Jang,Young Kyu Park,Soon Pal Suh,Dong Wook Ryang 한국미생물학회 2004 The journal of microbiology Vol.42 No.2

Pulsed-field gel electrophoresis (PFGE) typing was applied to the epidemiological investigation of 21 Candida tropicalis isolates collected from urine specimens of 11 patients and one healthcare worker, in an intensive care unit (ICU) over a 4-month period. Seventeen epidemiologically unrelated strains from 14 patients were also tested to determine the discriminatory power of PFGE. PFGE typing consisted of electrophoretic karyotyping (EK) and restriction endonuclease analysis of genomic DNA (REAG), using two restriction enzymes (BssHII and SfiI). The EK pattern was the same in all 38 isolates, while REAG using SfiI separated the isolates into nine types. However, 16 different PFGE types were identified by REAG with BssHII, and the same results were obtained when the results of both REAG tests were combined. In serial urinary isolates from 10 patients, all strains from each patient had the same PFGE pattern. While the epidemiologically unrelated strains from 14 patients consisted of 13 different PFGE types, the 20 isolates from the 11 ICU patients fell into only two PFGE types (types C1 and C2), and these apparently originated from the two different outbreaks. All strains of type C1 (n = 12) were isolated from six patients, between November 1999 and January 2000, and all of the type C2 strains (n=8) were isolated from five patients, during January and February 2000. This study shows two consecutive clusters of C. tropicalis candiduria in an ICU, defined by PFGE typing, and also demonstrates that a PFGE typing method using BssHII is perhaps the most useful method for investigating C. tropicalis candiduria.

Shift of Colorimetric Values in Ishihara Pseudoisochromatic Plates with Plate Aging

( Joon Young Hyon ),( Jin Hak Lee ),( Won Ryang Wee ) 대한안과학회 2005 Korean Journal of Ophthalmology Vol.19 No.2

Purpose: This study aimed to quantify the shift of colorimetric values in the Ishihara pseudoisochromatic test with aging of the plates. Methods: Three sets of Ishihara pseudoisochromatic plates with different published dates (printed in 1971, 1983 and 2001) were tested. Positions matching 32 dots with 13 colors were chosen from each set and the colorimetric values with the CIELAB and HSB/HLS color systems were measured with a spectrophotometer. Lightness (L*), red-green (a*), blue-yellow (b*), chroma, red hue, yellow hue, and green hue values from each set were compared. Results: L* and chroma values were significantly higher in the older versions. The a* values shifted to red (increased a*) and the b* values shifted to yellow (increased b*) with plate aging. Conclusions: Our results showed that the pseudoisochromatic plates had significant changes in color values and a directional shift with aging.