• 한국주조공학회지
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• 제25권5호
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• pp.216-220
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• 2005

High ductility Al-Mg alloys often contain some Mn and Si, however the effects of these minor alloying elements on various properties of alloys have not been fully understood. In this study the castability and mechanical properties of Al-5%Mg alloy were investigated according to the addition of Mn and Si. The fluidity of the alloys was generally increased by increasing Si or Mn contents. The feedability was also increased by increasing Si content, but it was rather decreased by increasing Mn content. Both the tensile strength and the ductility appeared to be deteriorated by Si addition, while they were found to be improved by Mn addition.

• Journal of Astronomy and Space Sciences
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• 제17권2호
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• pp.173-180
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• 2000

아직 잘 연구 되지 않은 식쌍성 V651 Cas의 극심시각을 모두 수집하여 분석하였다. 그 결과, 이 쌍성의 공전주기가 규칙적으로 변화해 왔을 가능성을 발견하였다. 이를 제3천체에 의한 광시간 효과때문으로 가정하여 광시간 궤도요소를 구하였다. 최종적으로 구한 광시간 궤도의 주기, 반-진폭, 그리고 이심율은 각각 $5.^y66,\;0.^d00144$, 그리고 0.92이다. 이 논문에서 제시한 제3천체의 존재 확인을 위하여 극심시각의 많은 관측이 요구된다.

• Journal of Plant Biology
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• 제39권4호
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• pp.279-286
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• 1996

To know the changes of rbcL mRNA level by illumination, Northern hybridization analysis was performed with maize (Zea mays L.cv. Golden X Bantam). The average level of rbcL. mRNA in the light-grown shoots was 3.1 times higher than that of the dark-grown shoots after 6 to 10 growth days. The maximum difference of rbcL mRNA level between the dark-grown and the light-grown shoots was 5.1 folds. These results indicate that accumulation of rbcL mRNAin maize shoots is induced by light. Since the transcriptional DNA binding proteins and their cognate promoter elements, we carried out gel-retardation assays to elucidate the specific binding proteins on the rbcL promoter. It was found that plastid proteins of light-grown shoots bound to the R2 DNA fragment (-33 to -229) and R3 DNA fragment (-230 to -418 from ATG) of the rbcL promoter. From the results of competitive binding assays and heat or protease treatments, it was demonstrated that the bindings were sequence-specific DNA-protein interactions. Therefore, it could be concluded that the rbcL promoter region has at least two specific recognition sites for plastid proteins.

• 디자인학연구
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• 제16권4호
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• pp.243-254
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• 2003

본 연구의 목적은 마리오 보타에 의해 디자인된 천창과 지붕구조를 공간적, 형태적 관점에서, 빛의 연출 관점에서 분석하여 그 특성을 파악하는데 있다. 이 같은 목표에 따라 본 연구에서는 보타의 천창과 지붕구조를 잘 설명해 줄 수 있는 작품 13점을 선정, 디자인 원리에 입각하여 분석하고자 하였다. 본 연구를 통해 파악된 보타의 천창, 지붕구조의 특성은 아래와 같이 정리될 수 있겠다. 첫째, 벽돌과 같이 두터운 재료에 의해 제한되어 비교적 어두운 실내가 되는 보타의 작품에서 천창은 공간을 밝혀주는 주된 채광수단이 된다. 지붕구조는 천창으로부터 유입되는 빛을 효율적으로 분산 할 수 있도록 치밀하게 디자인되었다. 둘째, 그의 작품에서 천창과 지붕구조는 형태를 창조하는 요소로서 역할을 담당한다. 그것들은 작품 외관을 위해 고유한 이미지를 창출하는데 일조하며 실내공간에 형태를 부여하게 된다. 셋째, 천창은 또한 외부의 자연과 대화하는 창으로 실내에 기여한다. 사람들은 실내에서 천창을 통해 시간의 흐름을 감지하게 되며 하늘의 풍경을 감상할 수 있다. 넷째, 천창을 통해 유입되며 지붕구조에 의해 조절되는 빛은 보타의 실내에 특별한 분위기를 연출한다. 위로부터 떨어지는 빛을 갖는 실내에서 사람들은 신비로움과 경건함을 느끼게 된다. 다섯째, 천창은 또한 상징적 의미를 내포한다. 천창은 하늘과 땅 사이의 관계를 상징하기도 하며 교회 작품에서는 성도들에게 하늘나라의 비젼을 보여주기도 한다. 인공조명을 활용하여 단순한 실내를 강조하는 근래의 우리 작가들 작품과 비교할 때 천창과 지붕구조를 적극적으로 기용, 자연광의 이점을 취하며 이들을 조형요소로도 이용하는 보타의 작품은 우리 작가들의 작품과는 다른 또 다른 형식의 디자인을 제안하고 있다.

• 전기학회논문지
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• 제57권6호
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• pp.1116-1122
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• 2008

Since conventional methods for measuring stride length(distance) are many weaknesses, optical methods have been developed to measure stride length(distance) of human pedestrians. IR(Infrared) elements and Power LED(Light Emitting Diode) with two types of lens were used to correlate detected light intensity with stride length(distance). The suggested methods in this study are simple, convenient, and cost effective. The results can be used to analyze walking patterns of normal and disabled men, and to monitor the recovering processes of the disabled patients.

• 한국군사과학기술학회지
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• 제19권6호
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• pp.769-778
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• 2016

Technical approach on the modeling, simulation and experimentation methods, which are applied for developing a constructive simulation and engagement experimentation software for supporting light weight torpedo operational tactics study, is introduced. Conceptual modeling for the weapon engagement and simulation entities, mathematical models for the simulation elements, approach for the design of experimentations are described, and screen shots of the software are also presented as some example results of experimentation and analysis. It is found that the simulation and experimentation results are useful to support and fulfill the mission needs and requests. As a consequence, the technical approach is rated to be appropriate to accomplish the dedicated purpose of the simulation and experiments.

• Journal of Astronomy and Space Sciences
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• 제6권2호
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• pp.119-125
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• 1989

UBV observations of the primary eclipse of Algol-type long period eclipsing binary AY Persei have been successfully made using the 61-cm reflector at the Ilsan Station of Yonsei University Observatory in September and October, 1989. These light curves furnish ones to deduce following results; (1) the total duration of the eclipse lasted for about 0.066(0.78 days) with no clear evidence of the existence of the totality, (2) the depths of mid-eclipse of $0^m.91$ and $1^m.07$ for V and B, respectively, (3) two times of minimum light, JD2447820.203 and JD 2447820.200 for V and B, respectively, and (4) no period variation with the improved light elements, Min I =JD2427152.237+$11^d.776620e$, $pm$10 $pm$4 are made.

• Journal of Astronomy and Space Sciences
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• 제6권2호
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• pp.109-117
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• 1989

A total of 266 photoelectric observations(91 in V, 93 in B, and 82 in U) for an eclipsing binary, ZZ Cnc, has been secured by using the 61-cm reflector and an uncooled iP21 photomultiplier phototube of Yonsei University Observatory during 4 years from March 1984 to May 1988. One time of minimum light, JD 2446887.534 is obtained. Although Kim et al.(1988) suggested the possibility of the period change, the present study shows that the orbital period of ZZ Cnc should be constant. According in a reasonable interpretation of the eclipse light curves. Min I = JD Hel 2446887.574+25d.5944E $pm$2 $pm$2 may be useflul as new light elements for future observations.

• 한국기계가공학회지
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• 제11권5호
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• pp.76-81
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• 2012

The continuing demand for increasingly slimmer and brighter liquid crystal display(LCD) panels has led to an increased focus on the role of the light guide panels(LGPs) or optical films that are used to obtain diffuse, uniform light from the backlight unit(BLU). And the most basic process in the production of such BLU components is the micromachining. LCD BLUs comprise various optical elements such as a LGP, diffuser sheet, prism sheet, and protector sheet with micro patterns. High aspect ratio patterns are required to reduce the number of sheets and enhance light efficiency, but there is a limit to the aspect ratio achievable for a given material and cutting tool. Therefore, this study comprised a series of experimental evaluations conducted to determine the machining feasibility in microcutting various aspect ratio patterns on electroless nickel plated die materials when using single-crystal diamond tools. Cutting performance was evaluated at various cutting speeds and depths of cut using different machining methods and machine tools.

• Journal of the Optical Society of Korea
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• 제18권4호
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• pp.345-349
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• 2014

A direct-lit color-matching liquid crystal display using a lenticular lens array with grouped lens elements that image linear RGB light sources on the RGB subpixels of a color filter to enhance transmittance is designed, simulated, and fabricated. The RGB LED linear light sources were fabricated using small RGB LEDs in a linear array arrangement, and the lenticular lens array consisted of eight units of the same structure with a gap of 2.19 mm. The optical transmittance of the liquid crystal panel was improved by as much as 240% due to the color matching.