적응 루프법을 이용한 진화적 구조 위상 최적설계

황승민,박재용,임민규,오영규,한석영 한국공작기계학회 2009 한국공작기계학회 춘계학술대회논문집 Vol.2009 No.-

This paper presents a reliability-based topology optimization (RBTO) using bi-directional evolutionary structural optimization (BESO). Topology optimization is formulated as volume minimization problem with probabilistic displacement constraint. Young's modulus, external load and thickness are considered as uncertain variables. In order to compute reliability index, four methods, i.e., RIA, PMA, SLSV and ADL(adaptive-loop), are used. Reliability-based topology optimization design process is conducted to obtain optimal topology satisfying displacement and reliability index constraints with the above four methods, and then each result is compared with respect to numerical stability and computing time.

응력 제한조건하의 신뢰성 기반 형상 최적설계

오영규(Young-kyu Oh),박재용(Jae-kyu Oh),임민규(Min-gyu Im),박재용(Jae-yong Park),한석영(Seog-young Han) 한국생산제조학회 2010 한국생산제조학회지 Vol.19 No.4

The objective of this study is to integrate reliability analysis into shape optimization problem using the evolutionary structural optimization (ESO) in the application example. Reliability-based shape optimization is formulated as volume minimization problem with probabilistic stress constraint under minimization max. von Mises stress and allow stress. Young's modulus, external load and thickness are considered as uncertain variables. In order to compute reliability index, four methods, i.e., reliability index approach (RIA), performance measure approach (PMA), single-loop single￢vector (SLSV) and adaptive-loop (ADL), are used. Reliability-based shape optimization design process is conducted to obtain optimal shape satisfying max. von Mises stress and reliability index constraints with the above four methods, and then each result is compared with respect to numerical stability and computing time.

순차적 크리깅기법을 이용한 미소혼합기의 최적화

박재용,유진식,황승민,임민규,오영규,김용대,한석영,맹주성 한국공작기계학회 2008 한국공작기계학회 추계학술대회논문집 Vol.2008 No.-

An active micro-mixer, which is composed of an oscillating micro-stirrer in the micro-channel to provide effective mixing was optimized. The effects of molecular diffusion and disturbance by the stirrer were considered with regard to two types of mixer models: the simple straight micro-channel and micro-channel with an oscillating stirrer. Two types of mixer models were studied by analyzing mixing behaviors such as their interaction after the stirrer. The mixing was calculated by Lattice Boltzmann methods using the D2Q9 model. In this study, the time-averaged mixing index formula was used to estimate the mixing performance of time-dependent flow. The mixing indices of the two models were compared. From the results, it was found that the mixer with an oscillating stirrer was much more enhanced' and stabilized. Therefore, an approximate optimization of an active micro-mixer with an oscillating stirrer was performed using Kriging method with OLHD (Optimal Latin Hypercube Design) in order to determine the optimal design variables. The design parameters were established as the frequency, the length and the angle of the stirrer. The optimal values were obtained as 1.5754, 0.803D and ±45°, respectively. It was found that the mixing index of the optimal design increased by 83.36% compared with that of the original design.

Mini-implant를 이용한 III급 부정교합 환자의 협진 치료 : 문제중심의 교정치료

임동혁,김영신,조민아,김기성,양성은 대한치과교정학회 2007 대한치과교정학회지 Vol.37 No.4

자폐적 행동 양상을 보이는 아동과 어머니간의 애착 발달에 관한 분석적 연구

임숙빈,주세진,오민자,권미경,곽은영 대한간호학회정신간호학회 1994 정신간호학회지 Vol.3 No.1

This study was conducted to examine the feature of attachment and the main factors of attachment development between autistic child and his or her mother. Data was collected at Day Care Center for Children with Developmental Disorder in S National University Hospital through nurses's in S National University Hospital through nurses's participating observation, interview with the mothers, and review of nursing records, from April 2 to June 30, 1994. The subjects were all 6 children, one was a girl, the others were boys, and their mothers who participate at the sensory-integrative play for attachment promotion served at this center. Content analysis was done for data analysis. First, all data were categorized by main concepts, reciprocity and affect. Then these wee analyzd and discussed on the aspects of specificity, proximity, synchrony, joint attention, strong affect, emotional availability which were chosen as the components of attachment through literature review. The results of this study were summarized as follows : all subjects were underdeveloped, unstable and showed different level of mother-child attachment. But during the program their attachment behaviors improved little by little. The behaviors which represented specificity, proximity, and strong affect were increased considerably, on the other hand the behaviors which represented joint attention and emotional availability were scarce. The more mother and child had contact and interacted merrily, the more their attachment behaviors developed. Another important factors of attachment development in these cases were mother and child's each characteristics. Especially the child's autistic peculiarity, such as indifference, severe resistance, distracterbility, stereotype tendency, physical condition were major barriers of maintatining the mother-child interaction. Also mother's attitude to her child, raring skill and physical condition were influencing factors. A few mothers who were anxious and stubborn had much more difficulty to adjust to their children. The mother who had experienced happiness with her child, especially if the mother experienced more fun at the play by herself became more positive, active and flexible, and that mother-child interaction maintained much longer and improved. It was more critical to help them enjoy their interaction. Thus nurses had to plan and intervene more joyful and various play, and consider mother's need in addition to child's need. And The program should be strengthened to support the mother emotionally to maximize the therapeutic effect.

감성돔(Acanthopagrus schlegeli) 유래의 주화세포의 확립과 확립된 세포의 특성

임은영,강민수,오명주,정태성,정성주 한국어병학회 2003 한국어병학회지 Vol.16 No.3

감성돔 (Acanthopagrus schlegeli)의 비장에서 주화세포인 BSBS를 확립하고 세포의 특성을 검사하였다. BSBS세포는 60회 이상의 계대배양이 가능하였고 형태학적으로는 상피성 세포였다. 세포는 20℃, 10%의 FBS가 든 L-15배지에서 배양하는 조건에서 잘 자랐다. BSBS세포는 해양버나바이러스 (MABY Y-6), 잉어의 봄바이러스병바이러스 (SVCV), 넙치의 랍도바이스(HIRRV)와 연어바이러스 (CSV)를 접종했을 때 세포변성효과가 나타났다. 새로 확립된 주화세포는 앞으로 많은 바이러스병의 연구에 유용하게 사용할 수 있을 것으로 생각된다. A stable cell line, BSBS (black seabream spleen), was established from the cells in spleen of black seabream, Acanthopagrus schlegeli, and characterized. Subculture maintained more than 60 passages and mophologically, BSBS cell was epithelioid cell. The cells grew optimally at 20℃ in Leibovitz's L-15 medium supplemented with 10% fetal bovine serum with incubation temperature of 20℃. BSBS cells supported the growth of marine birnavirus (MABV Y-6), chum salmon reovirus (CSV), spring viremia of carp virus (SVCV) and hirame rhabdovirus (HIRRV). Thus, the new cell line may be useful for studying wide range of fish viruses.

신뢰성 지수에 의한 위상최적화

임민규,박재용,황승민,오영규,박재용,한석영 한국공작기계학회 2009 한국공작기계학회 춘계학술대회논문집 Vol.2009 No.-

The objective of this work is to integrate reliability analysis into topology optimization problems. The reliability index determines design domain and uncertainty value. The elemental sensitivity numbers are calculated from finite element analysis and then converted to the nodal sensitivity numbers in the design domain. A mesh-independency filter using nodal variables is introduced to determine the addition of elements and eliminate unnecessary structural details below a certain length scale in the design. To further enhance the convergence of the optimization process, the accuracy of elemental sensitivity numbers is improved by its historical information. Application of the RBTO model gives a different topology relative to DTO. It is found that the RBTO model yields more reliable optimal topologies than those produced by DTO.

Carbamazepine Degradation by Photolysis and Titanium Dioxide Photocatalysis

Im, Jong-Kwon,Son, Hyun-Seok,Kang, Young-Min,Zoh, Kyung-Duk Wiley (John WileySons) 2012 Water environment research Vol.84 No.7

<P>We investigated the degradation of carbamazepine by photolysis/ultraviolet (UV)-C only and titanium dioxide photocatalysis. The degradation of carbamazepine by UV-only and titanium-dioxide-only (adsorption) reactions were inefficient, however, complete degradation of carbamazepine was observed by titanium dioxide photocatalysis within 30 min. The rate of degradation increased as initial carbamazepine concentration decreased, and the removal kinetics fit well with the Langmuir-Hinshelwood model. The addition of methanol, a radical scavenger, decreased carbamazepine removal, suggesting that the hydroxide radical played an important role during carbamazepine degradation. The addition of oxygen during titanium dioxide photocatalysis accelerated hydroxide radical production, thus improving mineralization activity. The photocatalytic degradation was more efficient at a higher pH, whereas the removal of carbamazepine and acridine (a major intermediate) were more efficient under aerobic conditions. The mineralization of carbamazepine during photocatalysis produced various ionic by-products such as ammonium and nitrate by way of nitrogen dioxide.</P>

당뇨병환자에서 게이트심장혈액풀신티그라피를 이용한 심기능 평가

윤상임,송치운,이진홍,안미애,성기양,송민호,이강욱,신영태,김영건,노흥규 충남대학교 의과대학 지역사회의학연구소 1993 충남의대잡지 Vol.20 No.2

Major cardiovascular complications of diabetes are coronary atherosclerosis, diabetic dilated cardiomyopathy, autonomic neuropathy and those are major causes of morbidity and mortality in diabetic patients. Gated blood pool heart scan is noninvasive and useful method for evaluation of functional status of heart in diabetics. We evaluated 52 patients with diabetes and divided 3 groups. Group 1 were 11 patients without proteinuria or with proteinuria less than 550mng during 24 hours. Group 2 were 9 patients with proteinuria more than 550mg during 24 hours and group 3 were 32 patients with endstage renal diasese due to diabetes. We performed 99mTc-HSA cardiac gated blood pool scan and used left ventricular ejection fraction(LVEF), peak ejection rate(PEF) to indices of LV systolic function and peak filling rate(PER) to index of LV diastolic function. The results were follows : 1) LVEF, PER were significantly lower in diabetics with ESRD than diabetics without ESRD, but there were no significant difference between normal controls and diabetics without ESRD 2) PFR was significantly lower in diabetics than normal controls, but there were no significant differences in diabetics with or without nephropathy. 3) There were negative correlation between PER, PFR and duration of diabetes. On the basis of results, PFR is a LV functional index of GBPS which can disclose early change of LV dysfunction in patients with diabetes.

일개 제빵회사 근로자의 제빵공 천식 유병률

김정민,권영준,주영수,임형준,이태경,강혜련,백도명 大韓産業醫學會 2008 대한직업환경의학회지 Vol.20 No.3

목적: 일개 제빵회사에서 제빵공 천식 유병률을 조사하여 제빵공 천식으로 인한 국내 질병부담을 파악하는데 기초자료를 제공하고자 하였다. 방법: 일개 제빵회사의 생산관련 근로자 596명에서 수습기간(3개월) 중이거나 참여를 거부한 216명을 제외하고,380명을 연구대상으로 하였다. 밀가루분진 노출형태에 따라 직접노출군과 간접노출군으로 직무 카테고리를 분류하고,설문조사는 ISAAC 설문항목에 직업력 등을 추가한 설문지를 사용하였다. 설문조사에서 천식이나 알레르기병과 관련된 증상이나 병력이 전혀 없는 간접노출군은 임상검사대상에서 제외하였다. 임상검사대상 233명에게 피부단자검사,혈청 특이 IgE 항체검사,산업의학 전문의와의 면담을 시행하였고,면담에서 천식이나 알레르기비염과 관련된 증상이나 병력이 확인된 31명을 연속적 PEFR 측정대상으로 하였다. PEFR 변동률로써 메타콜린 기관지유발검사대상을 선정하였고,메타콜린 기관 지유발검사에서 기관지과민성이 확인된 경우에 특이 기관지유발검사를 시행하였다. 제빵공 천식은 특이 기관지유 발검사에서 천식반응이 확인된 경우로 정의하였다. 결과: 연구대상의 밀가루 민감화율은 21.0%(직접노출군 25.9%,간접노출군 13.3%), 제빵공 천식 유병률은 3.2%(직접노출군 5.1%,간접노출군 1.8%)였다. 직접 노출군이 간접노출군에 비해 밀가루에 민감화될 위험이 높았으며(OR 2.15,95% CI=1.03∼4.51), 제빵공 천식에 이환될 위험은 통계적으로 유의하지 않았다(PR 2.52,95% CI=O.78∼8.18). 밀가루에 민감화된 군이 그렇지 않은 군에 비해 제빵공 천식에 이환될 위험이 매우 높았다(PR 38.63, 95% CI=6.14∼243.22). 결론: 이번 연구결과는 직업적으로 밀가루에 노출되는 국내 근로자에서 제빵공 천식이 적지 않을 것임을 시사하고 있다. 향후 제빵공 천식으로 인한 질병부담을 보다 정확히 파악하기 위해서는 국내에서 연구된 바 없는 밀가루 취급 사업장(제분회사 등)에 대한 연구가 필요하며,근로자의 건강과 사회경제적 위치를 보호하기 위한 체계적인 연구도 요구된다. Objectives: To determine the prevalence of baker's asthma due to flour dust in an industrial bakery in Korea. Methods: Of the 596 active workers, 380 were allocated to a category of either direct exposure (DE) or indirect exposure (IE) to flour dust and completed a modified ISAAC questionnaire. Of the 380 participants, 233 were screened by an occupational physician interview, a skin prick test, and an ELISA for serum-specific IgE antibodies to wheat flour extracts. Selected workers received serial monitoring of peak expiratory flow rate (PEFR), and positive PEFR respondents received a methacholine challenge test. The diagnosis of baker's asthma was confirmed by a specific inhalation challenge with wheat flour extracts. Results: The prevalence of sensitization to wheat flour and baker's asthma was 21.0% (25.9% DE, 13.3% IE) and 3.2% (5.1 % DE, 1.8% IE), respectively. DE had an increased risk of sensitization to wheat flour (OR 2.15, 95% CI = 1.03∼4.51). Sensitization to wheat flour and the prevalence of baker's asthma correlated significantly (PR 38.63, 95% CI = 6.14∼243.22). Conclusions: These findings indicate a considerable prevalence of baker's asthma among flour-exposed workers in Korea. Future studies will be required to survey the situation in flour mill companies and seek ways to protect the health and socioeconomic position of flour industry workers.