• Food Science of Animal Resources
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• v.26 no.2
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• pp.263-268
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• 2006

Probiotics including Lactobacillus acidophilus, refer to a group of nonpathogenic organisms that protect the human host against gastrointestinal(GI) infections by pathogenic bacteria such as Shiga toxin-producing E. coli(STEC). In the study, the inhibitory effects of STEC ATCC 43894 adhesion by L. acidophilus A4 was investigated on the HT-29 epithelial cells. Specific proteins regulated by cell Iysates of L. acidophilus A4 on STEC ATCC 43894 were also characterized by proteomic analysis. Both cell mass and Iysate of L. acidophilus A4 have exhibited the profound inhibitory activity on the HT-29 cells(about 1.5 log scale reduction). Two-dimensional gel electrophoresis(2-DE) revealed seven proteins that were up-regulated by cell Iysates of L. acidophilus A4 and three proteins that were down-regulated. In addition, three protein spots were only detected in the presence of cell Iysates. These results suggest that inhibitory effects of STEC adhesion by L. acidophilus may be due to the regulation of specific protein of STEC.

• Journal of the Korea Concrete Institute
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• v.23 no.3
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• pp.339-346
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• 2011

The effects of mineral admixtures on the bonding properties of cement mortar to polyolefin based synthetic fiber were evaluated. The mineral admixtures consisted of 0%, 5%, 10%, and 15% fly ash, blast furnace slag, and metakaolin in cement. Bond interactions between the cement mortar and the polyolefin based synthetic fiber were determined by Dog-bone bond tests. Bond tests of the polyolefin based synthetic fiber showed an increase in pullout load with the strength of the cement mortar. Also, the interface toughness of polyolefin based synthetic fiber in cement mortar increased as the fly ash, blast furnace slag, and metakaolin contents increased. The microstructure of polyolefin based synthetic fiber surface was examined after the pullout test to analyze the frictional resistant force according to the replacement ratio of fly ash, blast furnace slag, and metakaolin during the pullout process of polyolefin based synthetic fiber in cement mortar. The scratched of polyolefin based synthetic fibers increased with the replacement ratio of fly ash, blast furnace slag, and metakaolin. Also, the interface toughness was enhanced by adhesion forces induced by the fly ash, blast furnace slag, and metakaolin.

• 한국HCI학회:학술대회논문집
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• 2007.02a
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• pp.553-560
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• 2007

본 논문에서는 양손의 터치를 인식하여 실시간 상호작용이 가능한 테이블 탑 디스플레이 시스템 및 구현 알고리즘에 대해 기술한다. 제안하는 시스템은 FTIR(Frustrated Total Internal Reflection) 메커니즘을 기반으로 제작되었으며 multi-touch, multi-user 방식의 손 제스처 입력이 가능하다. 시스템은 크게 영상 투영을 위한 빔-프로젝터, 적외선 LED를 부착한 아크릴 스크린, Diffuser 그리고 영상을 획득하기 위한 적외선 카메라로 구성되어 있다. 시스템 제어에 필요한 제스처 명령어 종류는 상호작용 테이블에서의 입력과 출력의 자유도를 분석하고 편리함, 의사소통, 항상성, 완벽함의 정도를 고려하여 규정하였다. 규정된 제스처는 사용자가 상호작용을 위해 스크린에 접촉한 손가락의 개수, 위치, 그리고 움직임 변화를 기준으로 세분화된다. 적외선 카메라를 통해 입력받은 영상은 잡음제거 및 손가락 영역 탐색을 위해 간단한 모폴로지 기법이 적용된 후 인식과정에 들어간다. 인식 과정에서는 입력 받은 제스처 명령어들을 미리 정의해놓은 손 제스처 모델과 비교하여 인식을 행한다. 세부적으로는 먼저 스크린에 접촉된 손가락의 개수를 파악하고 그 영역을 결정하며 그 후 그 영역들의 중심점을 추출하여 그들의 각도 및 유클리디언 거리를 계산한다. 그리고 나서 멀티터치 포인트의 위치 변화값을 미리 정의해둔 모델의 정보와 비교를 한다. 본 논문에서 제안하는 시스템의 효율성은 Google-earth를 제어하는 것을 통해 입증될 수 있다.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.450-453
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• 2011

압출공법(incremental launching method)은 교대 배후에 거더 제작장소를 설치하고, 콘크리트를 이어쳐서 교량거더를 제작하고, 이것을 잭(jack)으로 밀어내는 가설방법이다. 이 공법에 의해 시공되는 교량의 상부단면은 시공 중에 지간의 중앙부와 지점부에 일시적이나마 모두 위치하게 된다. 따라서 단면들은 자중에 의해 발생되는 최대 정모멘트와 최대 부모멘트, 그리고 최대 전단력을 모두 경험하게 되는 구조적 특성을 가지고 있다. 한편 거더의 캔틸레버 작용을 감소시키기 위하여 거더의 선단에 압출추진코(launching nose)를 부착시킨다. 상부단면에 발생하는 이 일시적인 응력의 크기는 압출추진코의 단면특성에 따라 달라진다. 본 논문에서는 압출추진코와 상부단면의 상호작용에 관한 해석식의 정확성을 유지하고, 활용도를 높이기 위해서 압출추진코를 유사등단면(강성;등단면, 중량;변단면)으로 가정하여 단순화된 해석식을 제안하였고, 압출추진코의 단면이 등단면으로 가정한 기존 해석식의 정확성을 향상시키기 위해서 다이아프램의 중량을 집중하중으로 치환시켜 변형된 등단면 해석식을 제안하였다. 그리고 제안된 2개의 해석식의 정확성과 활용성을 판단하기 위해 실제 ILM교량 설계자료들을 통해 전산구조해석 프로그램과, 기존 해석식들과 비교 분석 하였다.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.41-41
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• 2010

상온에 준하는 저온의 플라즈마를 발생시키는 장치들이 개발되면서, 저온 플라즈마와 생체조직간의 상호작용에 대한 연구가 큰 관심을 끌고 있다. 플라즈마에서 발생되는 다량의 이온과 활성종, 그리고 UV 등이 박테리아나 세포들과 작용함으로 해서 암세포 사멸, 치아 미백, 박테리아 살균/멸균, 지혈등의 효과들이 나타나고 있으며, 이러한 효과들을 극대화할 수 있는 장치 개발과 플라즈마와 생체조직간의 상호작용 메카니즘을 규명하는 것이 중요한 이슈가 되고 있다. 나노 금입자를 암세포의 막단백질인 FAK의 항체와 결합시킨 중합체를 만들어서, 암세포 표면에 나노 금입자붙이고, 플라즈마를 조사했을 때, 나노 금입자가 부착되지 않았을 경우에 비해서, 5배이상 사멸률이 증가하였다.[1] 변색된 치아에 미백제의 주성분인 과산화수소를 도포하고, 10분간 플라즈마를 조사하게 되면, 과산화수소만 도포했을 때에 비해, 치아 표면의 색이 3배이상 밝아지는 것을 관찰할 수 있었다. 과산화수소를 플라즈마에 노출시켰을 때, 활성종인 OH의 생성이 2배이상 증가하였고, 플라즈마에 의한 OH 생성의 촉진이 치아 미백효과가 증대되는 주된 요인인 것으로 추측된다.[2] 플라즈마에서 발생되는 O, $O_3$와 같은 활성종들은 살균력이 뛰어나기 때문에, 저온 플라즈마를 의료기구의 소독/멸균에 응용할 가능성이 아주 크다. 대장균이나 구강 세균이 플라즈마 처리로 5분이내에 멸균되는 것을 확인하였고, 핸드피스와 같은 의료기구를 오염시켜서 멸균 테스트를 수행하고 있다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.8
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• pp.3334-3338
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• 2012

This work has been performed to evaluate the strength of fixtures, which were attached to outer surface of propeller flask to prevent transient movement during filling and cooling stages at Ni-Al-Bronze casting of large marine propellers. Experimental work was carried out to evaluate forces exerted on flask fixtures by measuring strain changes of fixtures due to thermal expansion and contraction during casting processes. Numerical analyses were also made to verify the experimental results and finally to evaluate the validity of arrangement of flask fixtures for casting of marine propellers.

• Journal of Korean Society of Steel Construction
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• v.18 no.4
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• pp.405-416
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• 2006

In composite girders with steel embedded in concrete as preflex beams, horseshoe connectors and bar connectors are commonly used to achieve composite action. Considering the requirements on the concrete cover in the thin concrete part surrounding a steel member, it has limitations with respect to the use of stud shear connectors, and significant bond and friction resistance can be generated. High horizontal shear strength between the casing concrete and the steel section is needed to introduce prestress to the concrete section in the form of preflex beams.In this paper, experiments on the evaluation of the static strength of horseshoe connectors and bar connectors were conducted and the effects of bonds were also considered. Based on the test results, current design codes were estimated and more general design guidelines that consider the design concept of Eurocode were proposed for the connectors. A strength evaluation according to failure and compared with the test results.

• The Korean Journal of Malacology
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• v.32 no.1
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• pp.17-23
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• 2016

Ultrastructural studies of oocyte development and vitellogenesis associated with the follicle cells in female Phacosoma japonicus were investigated by electron microscope observations. Vitelloogenesis in the oocytes occured by way of endogenous autosynthesis and exogenous heterosynthesis: vitellogenesis occurred through a process of endogenous autosynthesis, which involves a combined activity of the Golgi complex, rough endoplasmic reticulum, and mitochondria. However, the process of exogenous heterosynthesis involved endocytotic incorporation of extraovarian precursors into the basal region of the early vitellogenic oocytes. In this study, follicle cells, which attached to the previtellogenic and vitellogenic oocytes, were easily found. In particular, the follicle cells were involved in the development of previtellogenic oocytes by the supply of nutrients, and vitellogenesis in the early and late vitellogenic oocytes by endocytosis of yolk precursors. The functions of follicle cells, which attached to mature oocytes, accumulate reserves of lipid granules and glycogen particles for vitellogesis in the cytoplasm of the follicle cells.

• Microbiology and Biotechnology Letters
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• v.14 no.6
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• pp.473-478
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• 1986

In order to elucidate the patterns of natural oils and fats assimilation by microorganisms, lipases properties of yeast and bacterium strain, Torulopsis candia Y-128 and Acinetobacter calcoaceticus KB-2, which could assimilate palm oil efficiently, were investigated. T candida Y-128 attached palm oil droplets directly, and assimilated unsaturated fatty acid more easily than saturated acids liberated by the action of its lipase. Lipase of A. calcoaceticus KB-2 was extracellular and appeared quickly from the beginning of log phase of growth, whereas lipase of f candida Y-128 appealed intracellular. The lipases of two strains seem to be only enough to utilize the lipid materials for their own growth, without accumulation of lipases in the culture broth. Lipases of the strains have 1 (3-)-positional specificities on triglycerides. The patterns of palm oil assimilation showed that two strains attached droplets of lipid materials directly and split off fatty acids at 1 (3-)-position of triglycerides first, and assimilated the reaction products via fatty acids metabolic pathway.

• Korean Journal of Applied Biomechanics
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• v.19 no.2
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• pp.257-264
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• 2009

The purpose of this study was to investigate the lower extremity kinematics and muscle activities of adductor longus(AL), gluteus medius(GME), gluteus maximus(GMA), biceps femoris(BF), rectus femoris(RF), gastrocnemius(GA), and tibialis anterior(TA) using three dimensional and Noraxon 8 channels EMG system during turn 0, 60, 90 and 120 degrees in patients with Parkinson's disease. Seven parkinson's patients and five healthy subjects were participated in the study. Participants with Parkinson's disease demonstrated significant differences in reduction of stride length and stride width. Also, they showed ill difference in muscle activities. The strength and balance of the lower extremity muscles may help to improve cutting movement and to prevent falling in parkinson's patients.