레이저 가공에서 빔변수가 미치는 영향에 관한 연구

강경구,방세윤,윤경구,황경현,이성국 동국대학교 산업기술연구원 1997 산업기술논문집 Vol.9 No.-

레이저 가공시 조사되는 레이저 빔의 특성을 나타내는 변수 - 예를 들면, 빔의 형상, 초점면과 소재사이의 거리, 빔 강도 분포, 빔의 발산각, 실제 빔이 퍼져가는 양상이 이상적인 Gaussian 빔에 비해 얼마나 큰지를 나타내는 beam quality factor 등 - 이 가공결과에 큰 영향을 미치는 것은 경험적으로 잘 알려져 있다. 특히 원적외선 레이저로 천공, 에칭 또는 엑사이머 레이저로 ablation 가공을 수행할 때는 이러한 빔특성 변수의 영향이 극대화된다. 본 연구에서는 중요한 빔특성 변수의 영향을 가능한 독립시켜 정성적 및 정량적으로 파악하기 위해 연속발진 모드의 레이저빔 사용시 열전도에 의한 손실을 고려하였으며, 문제를 단순화해 빔 또는 가공소재의 상대적인 움직임이 없는 천공 (또는 에칭제거)의 경우에 대하여, 수치모사를 통해 여러 가지 빔 변수의 변화가 가공결과에 미치는 영향을 살펴보았다. 레이저 빔의 초점의 위치를 표면에서 멀리하면 가공깊이는 감소하게 되며, 같은 간격일 때는 소재의 내부에 위치시키는 것이 다소 유리하다. 또한 빔의 발산각이 작고, beam quality factor 값이 1에 가까울수록 깊은 가공을 얻을 수 있음을 파악하였다. In laser machining such as drilling with CO_2 or Nd:YAG laser, and etching or ablation with Excimer laser, one of the most important parameters affecting the machining results is known to be beam characteristics. In this paper a study is performed through a numerical simulation with the appropriate model to investigate the effects of beam parameters qualitatively and quantitatively, especially in the process of laser drilling of ceramics and ceramic composites. Results of different beam conditions reveal that the machined hole becomes deeper as (ⅰ) the beam divergence gets smaller,(ⅱ) beam quality factor approaches unity, and (ⅲ) beam focus lies nearer to the surface of the workpiece.

축구선수의 Detraining과 Retraining이 혈청지질 및 호르몬농도에 미치는 영향

정정화,박재현,채종훈,성혜련,황지인,윤미숙,노금선,윤종관,윤영학,노순덕,정경숙,박일규,김은희,박현태,박상갑 대한스포츠의학회 1999 대한스포츠의학회지 Vol.17 No.1

The purpose of this study was to investigate the effects of detraining and retraining on serum lipid and hormones in soccer players. Subjects were seven male high-school soccer players. V˙O_2max was determined for each subjects by administering a treadmill test(initial speed: 90m/min, grade: 5%, increasing speed per 3 min: 30m/min). Serum lipid(T-C, TG, HDL-C LDL-C) and hormones(epinephrine, norepinephrine, growth hormones, cortisol) were assayed pre and post detraining in 10, 20, 30 days after retraining. The repeated ANOVA was used to determine significant differences. The 0.05 level of significance was as critical level for the study. The results of the study were as follows: 1. V˙O_2max(ml/min) were 3576.3±204.2ml/min pre detraining, 3234.1±198.9 ml/min post detraining. There are significant(p<.05) difference between pre and post detraining. In 10, 20, 30 days after retraining, V˙O_2max(ml/min) were 3601.4±170.9 ml/min. There were significantly(p<.05) increased in retraining periods. 2. V˙O_2max(ml/kg/min) were significantly(p<.05) decreased from 62.3±2.9 ml/kg/min to 55.9±4.7 ml/kg/min in detraining. In 10, 20, 30 days after retraining, V˙O_2max(ml/kg/min) were 62.4±3.4ml/kg/min, 62.7±2.3ml.kg/min, 67.3±7.2ml/kg/min respectively. There were significantly(p<.05) increased in retraining periods. 3. T-C were significantly (p<.05) increased from 166.6±8.5mg/dl to 175.3±10.3 mg/dl in detraining. In 10, 20, 30 days after retraining, T-C were 160.1± 3.2mg/dl, 156.7±3.7mg/dl, 140.3±9.0mg/dl. There were significantly(p<.05) decreased in retraining periods. 4. HDL-C were 61.4±6.6mg/di pre detraining, 5.3±6.6mg/dl post detraining. There are significant(p<.05) difference between pre and post detraining. In 10, 20, 30 days after retraining, HDL-C were 56.9±7.1mg/dl, 56.4±9.2mg/dl, 57.7±9.1mg/dl respectively. There were no significant difference in retraining periods. 5. The hormones(epinephrine. norepinephrine, growth hormone, cortisol) were changed as same patterns. Epinephrine were 26.0±7.0[g/ml pre detraining, 24.6±3.2pg/ml post detraining. In 10, 20, 30 days after retraining, epinephrine were 26.9±5.6pg/ml, 30.6±6.2pg/ml, 29.4±5.6pg/ml respectively. There were no significant difference in retraining periods. In conclusion, HDL-C, epinephrine, norepinephrine, growth hormone and cortisol were decreased, T-C, LDL-C and TG were increased in detraining. But HDL-C, epinephrine, norepinephrine, growth hormone and cortisol were increased, T-C, LDL-C and TG were decreased in retraining.

재정적자 이대로 좋은가?

윤경현 건국대학교 1998 政治論叢 Vol.33 No.-

손마사지가 허혈성 심질환 환자의 불안에 미치는 효과

현경선,이향련,공송심,윤경자,김현섭,김효남,최지원,김운정 성인간호학회 2001 성인간호학회지 Vol.13 No.2

The purpose of this study was to investigate the effect of a hand massage program on anxiety, vital sign and pain in clients with ischemic heart disease. The design utilized for this stuffy was quail-experimental with a nonequivalent control group non-synchronized design The subjects were fifty-four patients, twenty-eight for the experimental and twenty-six for the control group, who were admitted with ischemic heart diease at a cardiac intensive care unfit in K medical center of K university. This study was carried out from May, 1999 to March, 2000. The level of anxiety and pain measured by Visual Analogue Scale, systolic blood pressure, diastolic blood pressure and pulse rate were measured before and after hand massage, the state of Anxiety was measured by the Spielberger (1970) scale at admission and after hand massage for three days. The collected data were processed by using the SPSS PC program and analyzed using χ2-test and t-test. The result of this study are as follows : 1. The scores of VAS anxiety and State of anxiety of the experimental group were lower than those of the control group. 2. The degree of systolic blond pressure, diastolic blood pressure and pulse rate of the experimental group were lower than that of the control group. 3. The score of VAS pain of the experimental group was lower than that of the control group. The results suggested that hand massage can decrease VAS anxiety, State of anxiety, vital signs and VAS pain of patients who were admitted with ischemic heart disease at cardiac intensive care unit Therefore, It Is proposed that hand massage is an appropriate nursing intervention to relieve anxiety of the patients who were admitted with ischemic heart disease at a cardiac intensive care unit.

Cubic B-Spline과 Quintic B-Spline 補間函數의 特性에 관한 硏究

윤경현,金定鐘 慶南大學校 附設 工業技術硏究所 1984 硏究論文集 Vol.2 No.-

本 論文에서는 工學이나 自然科學에서 使用되는 補間函數 中에서 cubic B-spline과 Quintic B-spline의 特性을 硏究하였다. 數直的 列로서f(χ)=cos(2πx)에 대한 각각의 結果를 SHARP-80MB micro computer system으로 비교하였다. Among the varous interpolating polymomials that used in engineering and natural science, we study about the characteristics of cubic B-spline and quintic B-spline interpolating polynomials. As an numerical example, we introduce f(χ)=cos2πx and compared each results with SHARP 80-MB micro computer system.

Candida albicans의 표면 iC3b 수용체 발현 및 혈관 내피세포에 대한 유착

이광훈,윤문수,윤경한,최현주 대한의진균학회 1996 대한의진균학회지 Vol.1 No.1

Background: The adherence of microorganisms to host tissue is an important process in the pathogenesis of fungal infection. A protein that shares antigenic and structural homology with the α-subunit of leukocyte adhesion glycoprotein CD11b/CD18, also known as iC3b receptor, Mo-1 or Mac-1, has been isolated from the surface of C. albicans. Objective: This study was done to observe the changes in the expression of iC3b receptor on C. albicans by glucose or immunosuppressive agents and to elucidate the effect of glucose and anti-iC3b receptor antibodies on adhesion between human dermal microvascular endothelial cells(HDMEC) and C. albicans. Methods: We utilized immunofluorescence study and immunofluorescent flow cytometry and the binding assay of C. albicans to cultured HDMEC in vitro and blocking assay using monoclonal antibody were performed. Results: Immunofluorescence study and immunofluorescent flow cytometric analysis demonstrated surface expression of iC3b receptor on C. albicans The expression of surface iC3b receptor on C. albicans in creased in a dose dependent manner with increasing concentrations of glucose, cyclophosphamide and prednisolone. The adherence of C. albicans to HDMEC correlated positively with glucose levels. The adherence of C. albicans to HDMEC decreased significantly by the treatment with anti-iC3b receptor antibodies. Conclusion: The results suggest that iC3b receptors should be involved in the adherence of C. albicans to vascular endothelial cells and may be involved in the pathogenesis of hematogenous candidiasis.

비만을 동반한 위암 환자에서 두 병을 같이 수술 치료한 경험(증례)

최경현,윤기영,문형환,신연명,서경원,안수미,송윤미,석정희,정경연,이은하 고신대학교의과대학 2008 고신대학교 의과대학 학술지 Vol.23 No.3

Obesity is growing problem in Korea. We had a case of bariatric surgery during gastric cancer operation. Patient was 29 year old Korean lady with early gastric cancer located in the lesser curvature side of the middle 1/3 of the stomach. Her body weight was 89 kg, height 163 cm, and thus body mass index was 33.5 kg/m2. Preoperative blood pressure was 130/90 mmHg, hemoglobin 12.9 g/dL, total lymphocyte count 3,280/mL, serum albumin 4.3 g/dL, CEA 1.1 ng/mL, CA 19-9 9.1 ng/mL, and alpha fetoprotein 2 ng/mL. Another associated disease was right thyroid follicular neoplasm. The chest X-ray was normal. After IM injection of 2,500 units of heparin 30 minutes before the induction of general anesthesia, she received curative subtotal gastrectomy and Roux en Y gastrojejunostomy when a malabsorption loop of 120 cm jejunum was incorporated between the Treitz ligament and the end to side jejuno-jejunostmy site at May 29th 2006. Her postoperative course was uneventful except a minor wound seroma and the elevations of serum amylase(up to 4 folds) and lipase(up to 2 folds). She lost her body weight 9 kg in 5th, 21 kg in 7th, and 27 kg in 10th postoperative months to became 61.5 kg. On follow up exams in July 2008, she gained 4 kg to overcome her weakness and fatigue. From the above result, the incorporation of a malabsorption loop during reconstruction phase of gastric cancer operation was a good option for obese gastric cancer patients especially in cases of early gastric cancer.

광학 마이크로패턴의 광산란 Simulation에 관한 연구

윤철용,현동훈,유경선 한국공작기계학회 2009 한국공작기계학회 춘계학술대회논문집 Vol.2009 No.-

This paper has to gain visual effect as light scattering by various angle and phase using optical micro pattern for metal. Also applying to optical micro pattern for metal surface design by developing optical technology and ultra-precision machining technology.

ATHB12, an ABA-lnducible Homeodomain-Leucine Zipper (HD-Zip) Protein of Arabidopsis, Negatively Regulates the Growth of the Inflorescence Stem by Decreasing the Expression of a Gibberellin 20-Oxidase Gene

Ora Son,허윤선,김윤경,이현정,김성한,김미란,남경희,이명석,김부용,박종범,박정안,이석찬,Atsushi Hanada,Shinjiro Yamaguchi,이인정,김승기,윤대진,Eva So¨derman,천충일 Sookmyung Women's University Research Institute of 2010 여성과 건강 Vol.6 No.1

말티즈개의 구강에서 발생한 골육종

정윤경, 조현예, 이상섭, 김미희, 이계리, 변현섭, 장동우, 안병우 충북대학교 동물의학연구소 2007 Journal of Biomedical and Translational Research Vol.8 No.1

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