• 한국생산제조학회지
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• 제23권1호
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• pp.94-101
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• 2014

Recently, in order to reduce the time required to replace an optical jumper cord, many researchers are using a field-installable connector and applying the ferrule polishing method, ferrule mechanical contact method, or ferrule fusion contact method. However, the process of arranging the length of the optical fiber, i.e., inserting the optical fiber into the ferrule by hand and checking its cross section, takes 60% of the time required for the entire process, which increases the overall cost. Therefore, in order to make this task more cost-effective, we will develop an automated inspection system with automatic cross-sectional arrangement of a field-installable connector. This system will be able to decrease the failure rate from 10% to 2% compared with the conventional method when cutting the optical fiber inserted into the ferrule. It will also improve the productivity by decreasing the test time by 28% compared with the conventional method. Our studies showed that it was possible to reduce the production costs and improve the quality of a field-installable connector, and we expect it to dominate the market.

• Restorative Dentistry and Endodontics
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• 제34권4호
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• pp.364-370
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• 2009

본 연구의 목적은 strain gage와 LVDT (linear variable differential transformer) 변위센서를 이용하여 섬유 보강 복합레진에서 섬유의 방향이 복합레진의 중합수축에 미치는 영향을 알아보기 위함이다. 지름 10 mm, 높이 2 mm의 원반 모양 유동성 복합레진 (Aeliteflo A2, Bisco, Inc., IL, USA) 중앙에 유리섬유 (X-80821P Glass Fiber, Bisco, Inc., IL, USA)를 위치시키고, 섬유가 배열된 장축 방향 (longitudinal)과 수직방향 (transversal)의 중합수축량을 strain gage (Linear S-series 350${\Omega}$, CAS, Seoul, Korea)를 이용하여 각각 측정하였다. 사용된 유동성 복합레진 자체의 free 중합수축을 구하기 위해 지름 7 mm, 높이 1 mm의 원반 모양 시편의 수직 방향 (axial) free 중합수축값을 LVDT로 측정하였다. 중합된 시편들을 절단하여 주사전자현미경으로 복합 레진 내부의 섬유배열을 관찰하고 각 군에서 측정된 평균 수축값들을 ANOVA로 비교하였고 Scheffe post-hoc test로 사후 검정하였다 (${\alpha}$=0.05). 섬유가 배열된 평면 상에서 복합레진의 중합수축 (radial shrinkage)은 섬유와 평행한 방향에서 감소하고 섬유와 수직한 방향에서 증가했다 (p<0.05). 본 연구의 결과 섬유 보강 복합레진으로 스플린트나 수복물을 제작할 때 중합수축량은 보강된 섬유의 배열방향에 따라 큰 차이가 남을 알 수 있었다.

• 대한방사선기술학회지:방사선기술과학
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• 제29권4호
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• pp.275-284
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• 2006

본 연구는 X-선을 생쥐 생체에 조사한 후, 방사선 조사선량에 따른 난소조직의 형태적 변화를 Masson's trichrome, 세망섬유 염색법 등의 조직화학반응을 확인한 결과 X-선을 조사한 난소조직은 방사선량이 증가함에 따라 성장 난포의 형태적 변화가 뚜렷하였으며, 특히 과립층세포의 변성에 의한 핵은 응축과 투명대의 변화가 현저하였다. 또한 Masson's trichrome 염색과 세망섬유 염색을 통한 조직화학반응의 결과 과립층세포의 변화와 난포기저막의 변형, 그리고 세망섬유의 비정상적 배열이 확인되었다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 추계 학술논문 발표대회
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• pp.25-26
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• 2018

Various concrete material technologies and new materials have been developed in accordance with the advancement of buildings. As part of these new technologies, light transparent concrete, which was invented by Hungarian architect Aron Losonczi and attracted worldwide attention, has a technique of arranging optical fiber inside concrete and transmitting the light from exterior to concrete to show silhouette inside. However, due to many disadvantages, application to the field was limited and commercialization was not easy. In Korea, Light Emotion Friendly Concrete has been developed for commercialization. In order to solve the degradation of construction performance caused by the arrangement of expensive optical fiber, which is pointed out as a disadvantage of translucent concrete, It converts expensive fiber into low cost acrylic rod, easy to arrange, pre-assembled to form and post-cast. Therefore, this study aims to improve the mechanical properties of LEFC and to derive optimal combination.

• 조명전기설비학회논문지
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• 제17권4호
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• pp.50-56
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• 2003

본 논문에서는 유입변압기 진단을 목적으로 부분방전시 발생하는 여러 가지 물리적 화학적 현상중 초음파를 검출하기 위하여 광섬유 Mach-Zehnder 간섭계를 구성하였다. 구성된 광섬유 센서의 초음파 검출 평가 실험을 실시하고, 절연유 중에 배치한 침-평판전극에 교류 고전압을 인가하여 방전시 발생하는 초음파를 측정하고 퓨리에 변환 및 wavelet 변환을 이용한 데이터 분석 결과를 나타냈다.

• Journal of the Korean Wood Science and Technology
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• 제50권2호
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• pp.134-147
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• 2022

The objective of this study is to determine the effect of fiber direction arrangement and layer composition of hybrid bamboo laminate boards on the physical and mechanical properties. The raw material used was tali bamboo (Gigantochloa apus (J.A. & J.H. Schultes) Kurs) rope in the form of flat sheets (zephyr) and falcata veneer (Paraserianthes falcataria (L) Nielsen). Zephyr bamboo was arranged in three layers using water-based isocyanate polymer (WBPI) with a glue spread rate of 300 g/m². There were variations in the substitution of the core layer with falcata veneers (hybrid) as much as two layers and using a glue spread rate of 170 g/m². The laminated bamboo board was cold-pressed at a pressure of 22.2 kgf/cm² for 1 h, and the physical and mechanical properties were evaluated. The results showed that the arrangement of the fiber direction significantly affected the dimensional stability, modulus of rupture, modulus of elasticity, shear strength, and screw withdrawal strength. However, the composition of the layers had no significant effect on the physical and mechanical properties. The bonding quality of bamboo laminate boards with WBPI was considered to be quite good, as shown by the absence of delamination in all test samples. The bamboo hybrid laminate board can be an alternative based on the physical and mechanical properties that can meet laminated board standards.

• Asian-Australasian Journal of Animal Sciences
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• 제31권5호
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• pp.721-728
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• 2018

Objective: This experiment was conducted to determine the differences in the apparent ileal (AID) and total tract digestibility (ATTD) of nutrients and indispensable amino acids (IAA) in high-fiber diets with wheat middlings, rice bran or alfalfa meal fed to Duroc${\times}$(Landrace${\times}$Yorkshire) (DLY) and Duroc${\times}$ (Berkshire${\times}$Jiaxing) (DBJ) growing barrows. Methods: Eighteen DLY and 18 DBJ growing barrows were randomly allotted to a $2{\times}3$ factorial arrangement involving 2 crossbreeds and 3 high-fiber diets. The experiment lasted 15 d with 10 d for diets adaptation, 3 d for feces collection and 2 d for digesta collection. Three diets were based on corn and soybean meal with 25% wheat middlings, rice bran and alfalfa meal respectively. Results: DBJ had a greater (p<0.05) AID of isoleucine, leucine, lysine, phenylalanine and valine and a lower (p<0.05) AID of methionine than DLY. The hindgut disappearance of acid detergent fiber for DBJ was greater (p<0.05) than DLY. The ATTD of gross energy, dry matter, organic matter, neutral detergent fiber and acid detergent fiber in wheat middlings diet were greater (p<0.05) than in rice bran and alfalfa meal diets. The hindgut disappearance of neutral detergent fiber and acid detergent fiber in wheat middlings diet or rice bran diet were the highest or lowest (p<0.05), and those of alfalfa meal diet were the middle. Barrows fed rice bran diet had a greater (p<0.05) hindgut disappearance of gross energy, dry matter and organic matter and lower hindgut disappearance of neutral detergent fiber and acid detergent fiber than barrows fed alfalfa meal diet Conclusion: DBJ growing barrows showed a significant higher digestibility of fiber in the hindgut and most IAA in the small intestine compared with DLY barrows. The digestibilities of chemical constituents and IAA were affected by the diets formulated with different fiber sources.

• 폴리머
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• 제24권6호
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• pp.860-868
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• 2000

본 연구에서는 섬유등급, 배향각 및 적층방법을 달리하여 제조한 탄소섬유강화 복합재료의 제조변수에 따른 전자파 차폐 특성에 관하여 고찰하였다. 그 결과, 탄소섬유강화 복합재료의 전자파 차폐효과는 섬유의 배향각도에 크게 좌우되었다. 특히 0$^{\circ}$의 배향각에서는 섬유의 등급에 따른 영향을 나타내었으며, 동일한 탄소섬유라 할지라도 배열방향에 따른 전기적 성질의 변화, 즉 전기적 이방성이 클수록 차폐효과는 커졌다. 각각의 적층방법에 따라 제조된 모든 시편은 83~98%의 차폐효과를 나타내었으나, 대칭구조와 비대칭구조에서는 적층각도가 커짐에 따라 차폐효과가 소폭 감소하였다. 그러나 반복구조에서는 위의 두 가지 구조와는 다른 경향을 나타내었으며, 특히 90$^{\circ}$ 반복구조의 경우 측정 주파수 전 영역에 걸쳐 90% 이상의 차폐력을 나타내었다.

• Structural Engineering and Mechanics
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• 제20권6호
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• pp.727-745
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• 2005

The present study is an experimental investigation into the behaviour of high strength concrete square short columns subjected to biaxial bending moments and strengthened by GFRP laminates. The main objectives of the study are: to evaluate the improvement in the structural performance of HSC short square columns subjected to small biaxial eccentricity when strengthened by externally applied FRP laminates, and to investigate the optimum arrangement and amount of FRP laminates to achieve potential enhancement in structural performance especially ductility. The parameters considered in this study are: number of FRP layers and arrangement of wraps. The load eccentricity is kept corresponding to e/t = 0.125 in two perpendicular directions to the columns principal axes, and the wraps are applied in single or double layers (partial or full wrapping). In the present work, test results of five full scale concrete columns are presented and discussed. The study has shown that FRP wraps can be used successfully to enhance the ductility of HSC columns subjected to biaxial bending by 300%.

• 대한본초학회지
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• 제20권4호
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• pp.33-39
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• 2005

Objectives : Because Ligusticum sinense Root as well as those of Angelica tenuissima Root are sole as Gobon(藁本) in domestic markets, morphological characteristics of them are attempted to be distinguished. Methods : The slice of the tested material made by paraffin section technique was colored with Safranine Malachite Green contrast methods, and then observed and photographed by olymphus-BHT. Results : 1. Angelica tenuissima Root has considerable number of thick roots, but Chinese Ligusticum sinense Root and Ligusticum jeholense Root are composed of rhizomes mostly with small roots. 2. Intersection of rhizomes of Angelica tenuissima Root shows a 'V'-like arrangement of xylem vessel. 3. Chinese Ligusticum sinense Root and Ligusticum jeholense Root did not show the 'V'-like arrangement, and sliced fiber bundles were found in xylem. 4. There was no difference between Chinese Ligusticum sinense Root and Ligusticum jeholense Root. Conclusions : In conclusion, Angelica tenuissima Root, Chinese Ligusticum sinense Root, and Ligusticum jeholense Root show characteristic differences in internal forms, so that it is possible to distinguish them with optical microscope.