• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1552-1554
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• 2002

본 논문에서는 실리콘을 기초로 한 포토다이오드를 제작하여 현재 바이오센서에서 이용되고 있는 luminol 화학 발광을 전기적으로 검출하였다. 우선, 실리콘 웨이퍼에 이온주입을 통해 p-n 접합을 형성하고 Al 전극을 형성시켜 포토다이오드를 제작하였다. PDMS을 passivation 막으로 사용하여 horseradish peroxidase(HRP) 농도 변화에 따른 발광의 최적조건과 luminol, HRP가 섞인 용액에 서로 다른 양의 과산화수소를 넣어 발광이 최대로 발생하는 혼합비를 측정하였다. 최종적으로 2mM luminol, 25U HRP 조건 하에서 과산화수소 농도에 따른 화학 발광을 측정하였으며, $10{\mu}M$부터 $500{\mu}M$ 범위의 과산화수소 농도 변화에 따른 포토다이오드의 감도는 단위 면적당 23.429pA/ ${\mu}M$이다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.7 no.2
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• pp.209-218
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• 2003

The analytical studies included nonlinear finite element analysis of split-tee connection details subjected to axial load and lateral load. A three-dimensional model of the connections between CFT columns and H-beams has been developed. Both initial geometrical imperfections and residual stresses are taken into consideration. A geometrically nonlinear load-displacement analysis of the structure containing the imperfection is then performed, using the Riks method. Analytical results are compared with existing experimental results. Extensive parametric analyses are carried out to investigate the relation of the connections between CFT columns and H-beam to various parameters such as the axial load, column width-thickness ratio, and split-tee thickness.

• Journal of Power System Engineering
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• v.9 no.1
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• pp.50-56
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• 2005

The corrosion experiment was performed for 120 hours on the specimens in the natural seawater tank with four steps of the loaded torsional stress. The surface corrosion pattern of SCM440 area was showed global corrosion and narrow pitting, that was cause by galvanic corrosion between friction welded IN713LC and SCM440. But corrosion does not proceeded from IN713LC area. Initially, the average relative electrode potential and corrosion current were decreased suddenly, by and large, it was stabilized gradually tend to decreasing with the elapse of the immersion time. The corrosion rate was decreased by increasing the load stress, but 200 MPa specimen was showed most large value.

• Journal of Welding and Joining
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• v.14 no.3
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• pp.41-47
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• 1996

The spot weldability of coated steels for automobile has been investigated. Coated steels of SPC-Zn DC, SPC Zn-Ni SC, SPC Zn-Ni DC, SPC Zn-Fe DC and OCCS were welded under different conditions of welding current, force and time. Coating thickness at the welded surface was reduced as increased welding current. Tensile shear strength(TSS) and cross tensile strength (CTS) were increased up to expulsion began, then dropped as increased current. Optimum conditions of welding force and time were different, however 200~250kgf and 15~20cycle were optimum for coated SPC (Steel Plate Cold). Weldability lobes were measured for each coated steel and they showed narrow range of working welding current. The organic composite coated steel (OCCS) had the highest current to get $\sqrt5{t}$ nugget size and narrowest working welding current range.

• Journal of Welding and Joining
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• v.12 no.3
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• pp.90-100
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• 1994

In this study the fatigue crack growth behavior was investigated for the surface cracks in aluminum alloy A5083-O plate and its weldment. Several kinds of specimens were tested at room temperature. The Eccentric specimens(E1.0, E2.5) subjected to combined stresses(tension+bending) were tested and the welded specimens with weld toes(TOE1, TOE2) were tested in order to verify the method to consider the stress concentration such as weld toe. It was ascertained that the surface crack growth property in the weld toe could be predicted by the corrected Pang's equation proposed in this study.

• Journal of Welding and Joining
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• v.3 no.2
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• pp.64-73
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• 1985

X선응력측정법은 결정의 각자간 거리를 표점으로 하는 각자변형도를 X선회절현상을 이용하여 직접규정하여 응력을 구하는 것이다. 따라서 비교재의 교정곡선으로 부터 간접적으로 응력을 측 정하는 자기법이나 초음파법 등의 비파괴측정법에 비하여 X 선응력측정법은 잔류응력과 같은 내부응력의 비파괴측정법에 알맞고 지금까지 많은 연구자에 의하여 용접부에 적용시키기 위한 시도가 행해졌었다. 앞서 말한 국제회의에서도 X선응력측정법을 취급한 논문이 6편이고 그 가운 데서 3편이 용접구조물 또는 이음부에 이 방법을 적용한 것이다. 그래서 본고에서는 먼저 용접 잔류응력의 발생기구와 계산법, 측정법에 대하여 기술하겠다. 똔 잔류응력이 용접이음부의 파괴 강도 및 용접균열에 미치는 영향, 용접잔류응력의 대책과 이용법에 대하여 일본에서의 연구를 중심으로 소개하겠다.

• Journal of Welding and Joining
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• v.2 no.1
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• pp.18-24
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• 1984

With the use of a new method the deformation mechanism of high-temperature-brazed joints can be obtained in a very short time. For that purpose a SEM(Scanning Electron Microscope) was equipped with a high temperature tensile testing machine. By means of SEM-investigation the damage behaviour of high-temperature-brazed joints is exa mined at elevated temperature. Based on these it is possible to make a qualification of the influence over single parts on the damage beginning and behaviour in dependence of temperature. This shall be shown exemplarily for the high temperature material NiCr20TiAl (Nimonic 80A).

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.8
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• pp.891-897
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• 2003

In this paper, a circular orthogonal polarizer is newly fabricated and used in a differential detector to reduce the optical noise in a wireless optical interconnection. The orthogonal polarizer is composed of two semicircular polarizers whose transmission axes are orthogonal each other, The orthogonal polarizer is driven by a motor and matched to the signal polarization in order to reduce the optical noise interference. The noise power was reduced by about 20 dB using a differential detector with the orthogonal polarizer.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.677-682
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• 2007

Nonlinear analysis of mixed structures is carried out by utilizing contact elements of a general finite element analysis computer program(ABAQUS). The present analysis focuses on the enhancing behaviors of mixed structure's connection type. Main 2 issues are related with discontinuity which reduce the stiffness of structure and proposing enhanced connection type. To validate the present study approaching 2 way, analytic one and experimental test.

• Journal of Welding and Joining
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• v.1 no.1
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• pp.6-12
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• 1983

탄산가스 아아크 용접법은 다른 용접법에 비해 전자세 용접의 기능, 용접능률의 우수성, 생산적인 측면에서의 뛰어난 경제성으로 인해 중공업 분야에서 그 적용 추세가 증가일로에 있다. 당사( 현대중공업)에서는 1981년에 탄산가스 아아크 용접법이 현장 구조물 시공에 최초로 적용된 이래 꾸준히 증가하여 보편적으로 시용되는 용접법 중위 하나가 되었다. 탄산가스 아아크 용접법의 여러 가지 장점을 적극적으로 이용하기 위해서는 탄산가스 아아크 용접시 발생하는 결함의 원 인을 분석하여 결함을 최소화하는 대책이 강구되어야 한다. 탄산가스 아아크 용접시 발생하는 결함의 빈도를 조사하여, 빈도수가 많은 결함의 원인을 분석하고 그 방지대책을 세우는데 본고의 목적이 있다.