Ti-6Al-4V 합금의 동적변형특성과 탄도충격성능 : 1. 초고속 폭발충격 특성 1. Ultra-high-speed Exploding Properties

이유환,이동근,이성학,이종수,최준홍,허선무 대한금속재료학회 2003 대한금속·재료학회지 Vol.41 No.10

The effects of microstructural morphology on ultra-high-speed exploding properties of Ti-6Al-4V alloy were investigated in this study. Exploding bridge wire (EBW) test was conducted on equiaxed and bimodal microstructures, which were processed by different heat treatments. From the test, moving velocity of free surface vs time profiles were obtained to measure strength at Hugoniot elastic limit (HEL) and spall strength and to subsequently predict ballistic mass efficiency. The EBW results indicated that impact resistance of the bimodal microstructure was better than that of the equiaxed microstructure when the measured strength at HEL and spall strength were considered. It was also learned from the observation of fractured EBW specimens that fracture occurred by the initiation and propagation of long cracks in the equiaxed microstructure, whereas a number of microcracks were formed and connected each other in a zig-zag pattern to reduce the driving force for crack propagation in the bimodal microstructure. Since the EBW test helped experimentally estimate ultra-high-speed deformation and fracture behavior, it could be effectively used for the prediction of ballistic impact performance.

Ti-6Al-4V 합금의 동적변형특성과 탄도충격성능 : 2. 동적비틀림 특성과 탄도충격성능 2. Dynamic Torsional Properties and Ballistic Performance

이동근,이유환,이성학,이종수,이충열,허선무 대한금속재료학회 2003 대한금속·재료학회지 Vol.41 No.10

The effects of microstructural morphology on dynamic deformation and fracture behavior and ballistic performance of a Ti-6Al-4V alloy were investigated in this study. Ballistic impact tests were conducted on equiaxed and bimodal microstructures, which were processed by different heat treatments, and then the test data were analyzed in relation to microstructures, tensile properties, and dynamic torsional test data. In the impacted region of the equiaxed microstructure, a number of adiabatic shear bands and cracks were observed to be formed along plastic flow lines, and delamination occurred because of cracking along the plastic flow lines or shear bands. In the case of the bimodal microstructure, shear bands were found in limited area near the impacted region without occurring delamination, and their number was fewer than that of the equiaxed microstructure. Thus, ballistic performance of the bimodal microstructure was better than that of the equiaxed microstructure. The ballistic performance of the two microstructures was also discussed by comparing the possibility of adiabatic shear band formation obtained from dynamic torsional test data.

녹비작물재배에 따른 고려인삼의 생육특성

Bong Jae Seong,Sun Ick Kim,Ka Soon Lee,Moo Geun Jee,Hyun Ho Kim,Jun Yeon Won 한국약용작물학회 2016 한국약용작물학술대회 발표집 Vol.2016 No.05

Background : The authors of this study analyzed the effect of the green manures cultivated in the soil of the preparation field in order to select the green manures suitable for ginseng cultivation and the effect of the green manures on the variation of ginseng growth development, the content of crude saponin and yield ability with the aim to use the results as the primary data for improving the quality of ginseng. Methods and Results: To analyze the effect of the application of green manures on the growth of ginseng, the authors cultivated 4 varieties of green manures and installed blue polyethylene sheet and one-layered black polyethylene net+three-layered blue polyethylene net(OBPNTB) and sun-shading material on the managed soil by re-applying green manures and then cultivated ginseng. The results suggested that the growth of ginseng was excellent in the barley+hairy, barely and rye cultivation plot in the plot treated with OBPNTB rather than the cultivation plot teated with Blue polyethylene sheet(BPS) and two-layered blue & two-layered black polyethylene net(TBTBPN), and the growth of leaf length and stalk diameter was excellent in barely + hairy vetch material. For the underground root weight, the growth was the most excellent(30.19g) in the barley+ hairy vetch cultivation plot treated with OBPNTB. For the underground red discoloration and root rot, the incidence rate was the lowest in the plot treated with BPS in which the water leak in a levee was small than in the test plot treated with sun-shading net. For the ginsenoside content in the cultivation plot treated with TBTBPN, the ginsenoid content was the highest in the rey cultivation plot, and it was the highest in the cultivation plot treated with OBPNTB. Conclusion : The results of study suggested rye among green manures is the most suitable for the growth of ginseng; underground growth was the most prominent in the plot treated with sun-shading net material (black 1 + blue 3) and the underground ginsenoside content was the most prominent in the rye cultivation plot and the plot treated with the sun-shading sheet.

단일 밴드 중적외선 영상으로부터 표면온도 추정을 위한 기초연구

박욱 ( Wook Park ),이윤경 ( Yoon Kyung Lee ),원중선 ( Joong Sun Won ),이승근 ( Seung Geun Lee ),김종민 ( Jong Min Kim ) 大韓遠隔探査學會 2008 大韓遠隔探査學會誌 Vol.24 No.2

3~5μm 파장대의 중적외선 영상은 화산 활동이나 산불과 같이 고온 현상을 관측하는데 효과적이다. 그러나 중적외선 영역은 지표의 복사율과 대기의 영향으로 인한 변화가 매우 심하고, 특히 낮 영상의 경우 태양 복사량에 의한 영향도 고려해야 하는 어려움이 있다. 따라서 단일밴드인 중적외선 영상을 이용하여 표면온도를 얻기 위해서는 영상이 취득된 시간과 장소에서 관측된 태양 복사량 및 여러 가지 대기 변수가 필요하다. 이 연구는 기존의 다중밴드 기반의 중적외선 영상 활용방법과 달리 단일 밴드 중적외선 영상을 이용하여 표면온도 측정을 위한 기초연구에 그 목적이 있다. 이를 위하여 MODIS 영상을 대상으로 MODTRAN을 사용하여 중적외선 영역의 대기보정 기법을 적용 한 뒤 복사전달 모델을 이용하여 지표의 온도를 측정하였다. 획득된 온도 영상의 정밀도를 측정하기 위해 기존의 온도 알고리즘인 MODIS Sea Surface Temperature 알고리즘에 의해 얻어진 해수온도와 비교를 통하여 오차 원인에 대해 분석을 실시하였다. 두 결과의 온도 차는 낮 영상의 경우 0.89±0.54℃ 밤 영상의 경우 1.25±0.41℃로 비교적 긍정적인 결과를 보였다. 그러나 낮 영상의 육지의 경우 대기에 의한 영향보다 태양빛의 반사가 주된 오차의 원인이 되며 이는 지표 복사율에 의한 영향이 매우 크게 작용하고 있음을 추정할 수 있다. 이 연구는 현재까지 해수에 대한 적용에 국한된 것으로 육상의 경우 복사율 변화가 매우 크기 때문에 중적외선 단일밴드에 의한 온도추정이 매우 어려울 것으로 예상된다. Middle-infrared (MIR) spectral region between 3.0 and 5.0 μm in wavelength is useful for observing high temperature events such as volcanic activities and forest fire. However, atmospheric effects and sun irradiance in day time has not been well studied for this MIR spectral band. The objectives of this basic study is to evaluate atmospheric effects and eventually to estimate surface temperature from a single channel MIR image, although a typical approach utilize split-window method using more than two channels. Several parameters are involved for the correction including various atmospheric data and sun-irradiance at the area of interest. To evaluate the effect of sun irradiance, MODIS MIR images acquired in day and night times were used for comparison. Atmospheric parameters were modeled by MODTRAN, and applied to a radiative transfer model for estimating the sea surface temperature. MODIS Sea Surface Temperature algorithm based upon multi-channel observation was performed in comparison with results from the radiative transfer model from a single channel. Temperature difference of the two methods was 0.89±0.54℃ and 1.25±0.41℃ from the day-time and night-time images, respectively. It is also shown that the emissivity effect has by more largely influenced on the estimated temperature than atmospheric effects. Although the test results encourage using a single channel MIR observation, it must be noted that the results were obtained from water body not from land surface. Because emissivity greatly varies on land, it is very difficult to retrieval land surface temperature from a single channel MIR data.

蔚山回夜貯水地 富營養化에 關한 調査硏究

李根善 보건장학회 1989 보건장학회보연구논문집 Vol.11 No.-

1996학년도 신입생 성격특성

이선화,정차근 창원대학교 학생생활연구소 1997 학생생활연구 Vol.10 No.-

물-공기 계면에서 긴 사슬 양 말단 작용기 분자인 α,ω-13,16-Dimethyloctacosanedioate Dimethylester(C_30DME)의 거동에 관한 연구

이정근,손대원,이관수,송석호,김현명,정선호 한양대학교 자연과학연구소 2001 自然科學論文集 Vol.20 No.-

물-공기 계면에서 표면압력의 증가에 따른 C30DME 분자의 구조 변화를 살펴보았다. 표면압력(π)-표면적(A) 등온선을 통해 표면적이 줄어들 때 C30DME 분자가 선형으로부터 역 U 자형 구조로 변하는 것을 확인하였다. C30DME의 역 U 자형 구조의 형성을 확인하기 위하여 Surface Plasmon Resonance (SPR)와 ellipsometry를 이용하여 Langmuir-Blodgett (LB) film 의 두께를 측정하였고 이 두께는 C30DME 분자의 역 U 자형 구조의 높이와 일치함을 관찰하였다. 또한 Atomic Force Microscope (AFM)을 이용한 표면 거침도 측정의 결과는 선형으로부터 역 U자형 구조로의 구조적 변화가 불연속이라는 것을 보여주었다. We investigated the conformational change of C30DME molecule with an increase on surface pressure at the air-water interface. The surface pressure (π)-area (A) isotherm indicates that the structure of C30DME changed from linear to reverse U-shape as the surface area was compressed. In order to confirm the formation of reverse U-shape, we examined the thickness of Langmuir-Blodgett (LB) film by a surface plasmon resonance (SPR) and an ellipsometry. The result of surface roughness measurement using an atomic force microscope (AFM) showed that the conformational change from linear to reverse U-shape is discontinuous.

부산 신항만지역의 환경친화적 에너지 수급계획 : 신항만지역의 표준기상데이터 작성 A Study on the Standard Weather Data for Busan Newport Area

이선애,김용경,이정재,조용수,도근영 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.1

Reclamation area has a characteristic nature surroundings than a town-region or a inland area. It has a adverse conditions; low temperature, gale, much sunshine, moistured salt; at climate than inland area. In case propelling development with examining enough topography and climate characteristics of Water Front, climatic environment would grow worth. And it would lead to a rise of energy and maintenance expenses by calculating inaccurate capacity of installed equipments and by occurrence of defects of equipments. On this study, final object is selecting a friendly environment facility system and establishing a accurate energy supply and demand program in grasp of climate characteristic on reclaiming and developing in Busan Newport Area. So we drew up it based on AWS(Automatic Weather System) measure data and standard climate data in Busan Newport Area.

하이브리드 시뮬레이티드 에닐링을 이용한 컨테이너 크레인의 최적제어에 관한 연구

김한근,박선국,강정호,이영진,이권순 慶南專門大學 2000 論文集 Vol.28 No.1

음식물 쓰레기를 이용한 발효사료 연구

강선철,이태근 대구대학교 생명과학연구소 2004 생명과학연구 Vol.3 No.1

Abstract : This study was carried out to establish the process for manufacturing of a fermented fodder using various food waste. The results obtained were as followings; (1) The fermented fodder was made with food waste from university's restaurant. (2) Rice bran, wheat bran and sesame dregs as additives were fitted for the fermentation process of food waste. It was available that amount of additives was 1.7 times of food waste, when the contents of moisture were controled at 30-35%. (3) Machine for fermentation was controlled at 80 , 10rpm, 3 ∼ 4 hours, putted the starter into the fermentor, and then mixed and fermented. (4) Over 3-5 days for fermentation were effective for food waste. (5) It had economic productivity according to raw materials price at that times, and yield of the fermented fodder was 72.8%.