Quantitative Analysis on Air-Dispensing Parameters for Manufacturing Dome Lenses of Chip-on-Board LED System

Jeon, Eun-Chae,Lee, Je-Ryung,Je, Tae-Jin,Choi, Doo-Sun,Ham, Young-Bog,Lee, Eung-Sug,Choi, Sang-Kyu,Kim, Hwi Korean Society for Precision Engineering 2014 International Journal of Precision Engineering and Vol.15 No.11

A COB(chip-on-board) LED(light emitting diode) system has advantages such as low cost and good heat dissipation. LED chips are bonded on PCB(printed circuit board) directly without packaging process in case of COB LED systems. Dome lenses made of polymeric resin are generally covered on the bonded LED chips by air dispensing for preventing mechanical damage and making white light. However, it is hard to control the shape of dome lenses precisely due to viscosity of the polymeric resin. We analyzed the relationship of the shape of dome lenses and experimental conditions of the air dispensing in this study. We introduced a new parameter, air pressure * dispensing time, whose physical meaning is impulse per unit area, and obtained much clear relationship of dispensing parameters and shape parameters of the dome lens. This relationship was similar to viscoelastic behavior. The aspect ratio (height over diameter) was increased as the new parameter increased, and was converged to a certain value. The maximum aspect ratio could be calculated by Young's equation of contact angle.

혼합방식을 사용한 OFDM의 PAR 경감방식의 성능 해석

장은영,전제훈,김성곤,변건식 동아대학교 정보기술연구소 2003 情報技術硏究所論文誌 Vol.10 No.2

OFDM should be used for the fourth generation communication for high speed communication. Because of high spectral efficiency and high tolerance to fading channel, OFDM is applied to many high speed wire and wireless communication such as DAB(Digital Audio Broadcast), DVB(Digita1 Video Broadcast), IMT 2000 etc. Inter-modulation, however, is derived from PAR(Peak to Average Power Ratio) of OFDM signals. The paper describes PTS(Partia1 Transmit Sequence) and SLM(Se1ect Mapping) of an existing methods which can reduce PAR. And then this papers proposed the new method that is called "Combine method". The method proposed in this paper is to combine PTS and SLM. As a result of the simulation, Combine PAR method is better than the existing methods.

30% 과산화수소를 함유한 전문가 미백제의 효용성 평가

김신영,박재억,김창현,양성은 大韓齒科保存學會 2010 Restorative Dentistry & Endodontics Vol.35 No.1

30% 과산화수소를 함유한 전문가 미백제인 레메화이트(Remewhite, Remedent Inc., Deurle, Belgium)를 시험군 피험자 31명, 시험용 미백제에서 과산화수소를 제외한 동일한 제재를 대조약으로 대조군 피험자 31명에게 1일 3회씩, 2차례에 걸쳐서 시행하였다. 미백의 임상적 효용성은 Colorimeter, Vitapan classical shade guide를 이용하여 전체 색변화량(□E*)을 측정하였다. 14주 후와 26주 후의 색변화량을 측정하여 군 간 색변화량을 비교하였고, 각 군 내에서의 색변화량도 비교하여 다음과 같은 결론을 얻었다. 1. Colohmeter를 이용한 평가시에 시험군에서 전체 색변화량(□E*)은 대조군에 비해 통계적으로 유의한 차이를 보였고, Vitapan classical shade guide를 이용한 평가시에는 통계적으로 유의한 차이를 나타내지 않았다(p < 0.05). 2. 시간이 지남에 따라 색 복원 현상이 나타남에도 불구하고 미백 시행 14주 후와 26주 후에도 미백의 효과가 유지된다고 할수 있다. 3. Colohmeter를 이용한 평가시에 Vitapan classical shade guide를 이용한 평가시보다 작은 색변화량을 더 정확하게 측정할 수 있다. This study evaluated the efficacy of an office bleaching gel (RemeWhite, Remedent Inc., Deurle, Belgium) containing 30% hydrogen peroxide. 31 volunteers were recieved office bleaching with the RemeWhite for 3 times at one visit, total 2 visits. As control group, the same gel in which hydrogen peroxide was not included was applied to 31 volunteers with the same protocol. The shade change (□E*, color difference) of 12 anterior teeth was measured using Colorimerter and Vitapan classical shade guide. The shade change of overall teeth in the experimental group was significantly greater than that in the control group which was measured using Colorimeter. There was also a significant difference between baseline and 14 weeks or 26 weeks though color rebounding phenomenon occurred as time went by. Small shade change difference can be measured accurately using Colorimeter than using Vitapan classical shade guide.

소아 신경심장성 실신환자에서 비정상적 심박수 프랙탈 상관에 대한 연구

김경용,주은영,염명걸,오재원,김창렬,김남수,이철범,노정일 대한소아과학회 2002 小兒科 Vol.45 No.9

수입각증후군에 의한 급성 복증 1례

정은욱,지삼룡,이영태,박지훈,김동기,제인수,채두근,박성재,박은택,이연재,이상혁,설상영,정정명 白中央醫療院 2005 仁濟醫學 Vol.26 No.1

Afferent loop syndrome is an uncommon complication of a gastrectomy and Billroth Ⅱ reconstruction. It may cause symtoms at any time from the first postoperative day to many years after the gastrectomy. Afferent loop syndrome is characterized by abdominal pain, vomiting and elevation of serum amylase. Thus, it is difficult to differentiate afferent loop syndrome from other cause of acute pancreatitis. However, the history of gastrectomy can be an important clue for diagnosing afferent loop syndrome. We experienced one case of chronic afferent loop syndrome with acute pancreatitis. After appropriate management, the abdominal pain disappeared and serum amylase level decreased. We report this case with a review of relevant literatures.

Preparation and Properties of Thermoplastic Polyurethane Elastomers

허재호,김태우,김은영,김한도 釜山大學校 1996 生産技術硏究所論文集 Vol.51 No.-

Isophorone diisocyanate (IPDI), 1,4-butanediol 및 polpropylene glycol로부터 2단계 중합 방법을 통하여 일련의 폴리우레탄 탄성체를 제조하였다. 이 폴리 우레탄은 IPDI와 1,4-butanediol로 구성된 경질 시그먼트와 PPG로 구성된 경질 시그먼트로 구성되어 있으며, 경질 시그먼트의 블록 길이와 함량을 변화시켰다. 경질 시그먼트의 함량(37.8∼66.7 wt%)에 따른 전이온도, 인장강도, 인장회복력, 경도 등을 조사하였다. A series of thermoplastic polyurethane elastomer were prepared via a two-step polymerization process using isophorone diisocyanate(IPDI), 14-butanediol as hard segment, and polypropylene glycol(PPG, Mw 3000) to give a soft segment. Hard block segment length and content(37.8∼66.7 wt%) were varied. The effects of hard-segment content, heat treatment on properties such as almost plateau modulus, glass transition temperature, hardness, tensile strength, and tensile retraction were investigated.

공황장애환자에서 광장공포증 동반여부에 따른 스트레스대처방식의 차이

최은영,제영묘,이대수,정영인 대한생물치료정신의학회 2001 생물치료정신의학 Vol.7 No.1

In an attempt to know the factors affecting the development of agoraphobia following panic attacks, the author investigated whether there are differences between coping strategies of panic disorder with and without ago-raphobia. Thirty-seven patients meeting the criteria of DSM-IV panic disorder were divided into 2 subgroups, one group with agoraphobia, another without agoraphobia. Questionaires for the severity of panic symptoms, and of anticipating anxiety for panic attacks, multidimensional coping scale for stress were administered to panic subjects. The results were summarized as follows. 1) Group of panic disorder with agoraphobia complaints trembling or shaking more than group of panic disorder without agoraphobia. 2) There was no differences of degree for the severity of anticipating anxiety between two groups. 3) Group of Panic disorder with agoraphobia had higher score on BDI than Group of panic disorder without agoraphobia. 4) Group of panic disorder with agoraphobia had lower score on active coping, positive interpretation, acceptance than group of panic disorder without agoraphobia, and the differences of these strategies between two groups were not correlated with the score on BDI at the time of investigation. In conclusion, these results suggest that the coping strategies for stress may be a predictor of agoraphobia in patients with panic disorder.

결정형 규산분진에 폭로된 섬유모세포의 자가증식 : Evaluation by H₂O₂and PDGF-AA 와 TGFβ

안병용,김경아,문제혁,정진숙,김은경,임영 대한산업의학회 2000 대한직업환경의학회지 Vol.12 No.2

Objectives : The aim of this study is to find out the activity of autoproliferation of rat fibroblast exposed to crystalline silica and the role of mediators secreted from rat fibroblast. Methods : The effect of α-quartz on production of growth factor (platelet-derived growth factor-AA and transforming growth factorβ) from rat fibroblasts were evaluated by ELISA and immunocytochemical analysis. Gene expression of these growth factors in rat fibrobast exposed to crystalline silica was evaluated by RT-PCR. Furthermore, fibroblast proliferation by culture supernatant of rat fibroblast was assayed by the neutral red test. Results : The amounts of H2O2 and growth factors synthesized in rat fibroblasts were significantly increased by the stimulation of crystalline silica (α-quartz) , which showed the dose-dependent manner to the concentration of α-quartz with the maximum response at the dosage of 100 ㎍/㎠. The result of RT-PCR demonstrated that α-quartz induced gene expression of PDGF-AA and TGFβ in rat fibroblast. We also found that supernatant of α-quartz-cocultured rat fibroblast induced a significant proliferation of fibroblast. Conclusion : Crystalline silica directly induce functional change In fibroblast such as increased release of reactive oxygen species and growth factors. The products of these functional change promote fibroblast proliferation via autocrine loop.

국내육성 오차드그라스 품종들의 캘러스 형성율 및 식물체 재분화 효율

김기용,강경민,배은경,이인애,임용우,최기준,박근제,손대영,조진기 Plant molecular biology and biotechnology research 2003 Plant molecular biology and biotechnology research Vol.2003 No.-

Comparisons of callus formation ratios from seed explants, callus sizes, regeneration ratios from callus and regeneration efficiency for 4 orchardgrass (Dactylis glomerata L.) varieties (Three were developed in Korea and one was imported from foreign nation) are as follows; Jangbeol 102 (67.0%) has the highest callus formation ratio in 4 weeks incubated callus after bedding the seed explants, but Potomac (68.4%) has the highest ratio in 6-seek callus. Potomac (3.93cm) has the highest callus size in 4-week callus, but Jangbeol 101 (4.32cm) has the highest size in 6-week callus. Jangbeol 101 (17.7%) has the highest plant regeneration ratio in 4-week callus, but Potomac (37.4%) has the highest raion in 6-week callus. Jangbeol 102 (11.5%) has the highest plant regeneration efficiency in 4-week callus, but Potomac (25.6%) has the highest efficiency in 6-week callus.

폐경기 여성의 운동형태가 골밀도에 미치는 영향

김은경,이계영,이삼준,심영제 한국스포츠리서치 2004 한국 스포츠 리서치 Vol.15 No.6

The relationship of bone mineral density and type of physical exercise was studied in 36 Postmenoposal Women(age 48-57). The exercise group consisted of Weight training([ =9), Aerobic dance(N=8), Swimming(N=9) and the control group consisted of 10 women. Bone mineral density was measured Lumber(L2-L4), Femur neck, Ward's triangle bone density. The results statstically analyzed on these data were summarized as follows: first, Lumber (L2-L4) bone density, Femoral neck bone density, Ward's triangle bone density in Weight training group was significantly higher than in Swimming group and Control group. Secondly, Lumber(L2-L4) bone density, Femoral neck bone density, Ward's triangle bone density in Aerobic dance group was significantly higher than in Swimming group and control group. Thirdly, No significant difference were round for Lumber(L2-L4) bone density, Femoral neck bone density in Weight training group and Aerobic dance group.