저압 MOCVD법에 의한 (100)-GaAs 기판 위의 Ga_xIn(1-x)P 성장과 특성

전성란,손성진,조금재,박순규,김영기 全北大學校 基礎科學硏究所 1994 基礎科學 Vol.17 No.-

x??0.51인 Ga_xIn_(1-x)P 에피층을 저압 MOCVD 성장법으로 TEGa(triethylgallium), TMIn(trimethylindium) 등의 MO(metalorganic) 원료와 PH_3(phosphine)를 사용하여 GaAs(100) 기판 위에 성장하였다. 성장조건에 의한 표면 morphology, 결정결함, 성분비, PL spectra, 운반자 농도와 이동도 및 DLTS spectra와 같은 성장층의 특성을 관찰하였다. 650℃의 성장온도와 V/Ⅲ 비, 즉 TEGa와 TMIn 두 원료의 유량에 대한 PH_3의 유량비가 160∼220일 때 가장 좋은 성장표면을 나타내었다. 성장률은 PH_3의 유량변화에 아무런 영향을 받지 않음을 알 수 있었다. Ga_0.51In_0.49P 에피층과 기판의 격자상수 차에 의한 격자 부정합 Δa_⊥/a_0은 약 (3.7∼8.9)×10 exp (-4)이었으며 실온과 5K에서 에피층의 PL 피크 에너지는 각각 1.85 eV와 1.9 eV였다. 성장층의 운반자 농도와 이동도는 V/Ⅲ 비에 따라 달라지는데 그 비가 120에서 220으로 증가함에 따라 농도는 1.8×10 exp (16) ㎝^-3에서 8.2×10 exp (16) ㎝^-3로 증가하였고 이동도는 1010 ㎝/V·sec에서 366 ㎝/V·sec로 감소하였다. Epitaxial layers of Ga_xIn_(1-x)P with x??0.51 were grown on the GaAs substrates oriented 2℃ off (100) toward <110> by low pressure MOCVD growth technique using triethylgallium (TEGa), trimethylindium (TMIn) and phosphine (PH_3). Surface morphology, crystal defects, composition, photoluminescence spectra, carrier concentration and DLTS spectra of the grown layers were investigated. Good quality epilayers with featureless surface were obtained at growth temperature of 650℃ and V/Ⅲ ratio, i.e., PH_3 flow rate divided by the sum of TEGa and TMIn flow rates, of 160 to 220. The growth rate turned out to have no dependence on phosphine flow rate. The lattice mismatchs Δa_⊥/a_0 between grown Ga_0.51In_0.49P epilayer and GaAs substrate were (3.7∼8.9)×10 exp (-4) and the PL peak energies of the epitaxial layer at room temperature and 5K were 1.85 eV and 1.9 eV, respectively. With increasing V/Ⅲ ratio i.e., phosphine flow rate, from 120 to 220, the carrier density and mobility of undoped epitaxial layers increased from 1.8×10 exp (16) to 8.2×10 exp (16) ㎝^-3 and decreased from 1010 to 366 ㎝/V·sec, respectively.

창작무용 수업에 있어서 협동학습과 경쟁학습이 중학생의 학업성취도에 미치는 영향

전향원,기한준,김성곤 한국스포츠리서치 2004 한국 스포츠 리서치 Vol.15 No.3

The purpose of this study was to analyze effects on academic achievements in compare with cooperative and competitive learning models of the creative dance instruction The Experiment was performed in instruction of 12. sessions, In this experiment was participated 74 middle school students, It was divided into cooperative group(n=39) and competitive group(n=35), Each group was recognized small group of 5-6 students and was given an individual role to each others. The measuring tools used in pre-test and post-test was an academic achievement testing sheet, That was conducted by creative ability evaluation standards. The results of this study was as followings Cooperative learning model in creative dance instruction was more effective for learner's academic achievements than competitive learning model, That is, it was more effective for originality, composition and continuity among sub-factors of academic achievements, In conclusion concrete methods to activate creative dance instruction which is in the important position in educational dance of the 7th curriculum can be found in cooperative learning model.

개에서 말기 외이염의 내과적 치료 증례

전민경,윤기영,최호정,정성목,송근호,이영원,박성준 忠南大學校 獸醫科大學 附設 動物醫科學硏究所 2008 動物醫科學硏究誌 Vol.15 No.1

A 8-year-o1d castrated male Shit-tzu dog was presented with chronic, severe and recurrent bilateral otitis externa. Clinical signs were stenosis, swelling, severe discharges from external auditory canal and pruritus of the ear. A diagnosis of the patient was made based on history, Physical examination, otoscopic examination, cytological examination and radiography. The dog was diagnosed to end-stage otitis externa and followed by treatment with systemic cyclosporine administration and topical solution. Clinical symptoms were resolved after 4 weeks cyclosporine therapy.

관상동맥질환자에서 경흉부 도플러 심초음파를 이용한 좌심실 확장기 기능의 평가 : 좌심실 확장기 장애 형태에 따른 분류

전희경,윤호중,유기동,박지원,전두수,정욱성,채장성,김재형,최규보,홍순조 대한순환기학회 1998 Korean Circulation Journal Vol.28 No.1

演習林 木本植物 調査에 관한 硏究

李命器,全哲,吳正壽,金成柱 圓光大學校大學院 1987 論文集 Vol.1 No.-

1. The tree grown in the university forest consisted of 54 families, 69 genera, 167 species, 15 varieties, 2 forma, so that the totaling were 185 taxa. 2. At a height of 500 meters over, the forest mostly consisted of Quercus variabilis forest. 3. We need to collect cork from Quercus variabilis growned massively and have enlarged artificial reproduction than now. 4. Cryptomeria japonica forest area that artificially reproducted at 11 block is a model managed forest. 5. According to the results, because the species defined the temperate zone, it is not suitable for the practice of students. Therefore, we need the positive act of university so that the forest species obtain the other forest zone.

超音波의 水處理 適用 可能性을 위한 實驗的 硏究

김성동,김전희,염승렬,백순기 동신대학교 환경연구소 1997 환경연구 Vol.2 No.1

BOD, 질소, 인 등이 다량으로 함유된 고농도 유기성 폐수는 BOB, 인, 질소 등 일부 오염물질의 농도가 현저하게 높거나 C/N비의 균형이 좋지 않은 특성 때문에 처리가 곤란할 뿐만아니라, 적정한 처리공정을 도입하는 것 또한 어려운 실정이다. 이에 따라 고농도 유기성 폐수 배출시설중 화학공장의 폐수를 처리대상 폐수로하여, 각각의 공정에서 배출되는 다른 성상의 폐수를 합한 원폐수를 초음파를 이용하여 무화(霧化 : fogginess)시킨 후 무화 전후의 BOD, COD, SS, N-H과중금속의 제거율을 분석한 결과, BOD, 55, N-H의 제거율은 높았으며 중금속의 제거에는 영향을 미치지 않는 것으로 나타났다. High concentration organic wastewater has been discharged out of industries. These industries are food industries, chemical industries, fiber industries, spinning factories, paper mill manufactories or night soil and stock breeding. Its wastewater was treated to fogginess using Ultrasonic Wave. Due to development of wastewater treatment technique, it is investigated by technique previous to the treatment. Acording to fogginess frequency, it was analysised variation of pollutants concentration. The conclusions are as fallows. Most pollutants were removed by fogginess using Ultrasonic Wave, while heavy metals were not removed Removal effect of BOD, COD, SS, N-H, T-N, T-P developed a tendency to decrease according to frequency.

초경 Step Drill의 절삭성에 관한 연구

변상기,장성규,이충엽,전언찬 동아대학교 공과대학부설 생산기술연구소 1997 生産技術硏究所硏究論文集 Vol.2 No.2

Cuttingability of carbide step drill is highly progressing the step drill with more then twice diameter rate is so difficult in regrinding and very easy to damage during machining. As the machining of step drill for blind hole is occur to breakage at small diameter position, so it is very difficult to machining. In this experiments, we investigate roundness and surface roughness by machining distance and were identified that the first distance, 5∼10m, was fine with 7㎛ but the around of 15m was happened so much alternation. And we were identified that after 20m was happend stable machining. The surface roughness was happened the same conditions. So application of step drill, we think that the selection of cutting conditions need lots consideration and the study of step drill's diameter ratio is carried out.

초경 드릴의 절삭 성능에 관한 실험적 평가 연구

장성규,변상기,이승수,김현수,전언찬 동아대학교 공과대학부설 생산기술연구소 1997 生産技術硏究所硏究論文集 Vol.2 No.1

Among the cutting process, recently hole processing in one of extensive using. This study, we made use of the 3 point edge drill. Regarding the cutting efficiency, we investigated the shape of cutting hole and studied cutting hole, a slope of center shaft, roundness and surface roughness. By using carbide 3 point cutting edge, compare with 2 cutting edge, it is possible that high precision drill processing and near the hole, at extremely limited area, quantity of magnification is a little big. After 15m cutting distance, a gradient of center shaft values was fixed 22㎛. It is necessary that a sufficient consideration concerned with jig intensity of workpiece, cutting conditions etc.

양측 하악과두 골절에 대한 관혈적 정보술후 나타난 근약화와 시력장애 : 증례보고

정기훈,신용길,김태열,신재명,윤규호,전인성 대한악안면성형재건외과학회 2000 Maxillofacial Plastic Reconstructive Surgery Vol.22 No.6

The condylar fracture show high occurrence rate in the following of symphysis and angle, because it is easy to have concentration of outer pressure due to its long and narrow anatomical shape and mouth opened state when trauma is attacked. For the clinical findings, there are trismus, opening deviation, mal-occlusion and open bite The classification of condylar fracture is varied due to the location of condylar bone fragment, fracture site. There are conservative and surgical methods for treatment modalities. Because of many advantages, conservative method is widely used it has no particular limits of treatment adjustment but the cases of absolutely surgical correction indication are easily found in clinical experience. Although many methods are suggested for treatments of condylar fracture, there are no particular surgical methods for precise reduction due to difficult accessibility in high condylar neck fracture. For precise reduction of condyle, we used Nam's method. However, in Nam's method, because condyle is fixed when once it is kept off externally reduced in avascular state, so complication such as condyle resorption is pointed out as a problem. In our clinic, we obtained some knowledge by treating a patient who had muscle weakness and vision disorder after temporary airway obstruction follownig the both condylar fracure operated using Nam's method, so here we reported the case with a study of documents.

기판 레벨 플립칩의 반복 굽힘 시험기의 개발

이용성,정종설,신기훈,정성균 한국공작기계학회 2007 한국공작기계학회 추계학술대회논문집 Vol.2007 No.-

Circuit board assemblies experience various mechanical loadings during assembly and in actual use. The repeated cyclic bending can cause electrical failures due to circuit board cracks, solder interconnects cracks, and the component cracks. This paper presents a cylic bending tester developed especially for evaluating the reliability of board level flip chips under the repeated cyclic bending. The tester employs the concept of 4-point bending test and complies to JEDEC standard No. 22B113 that is intended to evaluate and compare the performance of surface mount electronic components in an accelerated test environment. The performance of the tester will be estimated through the cross check of the test results in the future work.