• Composites Research
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• v.20 no.3
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• pp.37-42
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• 2007

Tensile residual stress is occurred by difference of coefficients of thermal expansion between fiber and matrix is one of the serious problems in metal matrix composite(MMC). TiNi alloy fiber was used to solve the problem of the tensile residual stress as the reinforced material. TiNi alloy fiber improves the tensile strength of composite with occurring of compressive residual stress in the matrix by its shape memory effect. A hot press method was used to create the optimal fabrication condition for a Shape Memory Alloy(SMA) composite. The bonding effect of the matrix and the reinforcement within the SMA composite by the hot press method was strengthened by cold rolling. In addition, acoustic emission technique was used to quantify the microscopic damage behavior of cold rolled TiNi/A16061 shape memory alloy composite at low temperature. The damage degree for the specimen that underwent thermal shock cycles was also discussed.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.23 no.6 s.165
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• pp.943-951
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• 1999

The welded structure unnecessarily remains residual stress due to the very high heating of local region and lastly cooling. The residual stress sometimes causes fracture initiation of welded structures. In this paper, distribution and magnitude of tensile and compressive residual stresses in the TIG(Tungsten Inert Gas) welded aluminum alloy such as Al5083-H112 are measured by using the hole-drilling method. Furthermore, the effects of residual stresses in the TIG welded aluminum CCT(Center Crack Tension) and SEN(Single Edge Notched) Specimens on the fatigue crack propagation behavior are analyzed. The fatigue cracks initiated at residual stresses region are influnced by tensile and compressive residual stresses. However, the effects are found to be released fast for both cases according to the cyclic loads and extension of crack length.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2016.06a
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• pp.250-252
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• 2016

본 논문에서는 과거와 현재지도를 자연스럽게 융합하여 살펴볼 수 있는 열 적외선 영상 기반 지도 조작 인터페이스 시스템을 제안한다. 이 시스템은 두 지도의 융합과 손가락 터치 검출로 구성되어 있다. 두 지도의 융합은 호모그래피 방법을 사용하여 과거지도를 워핑하고 이를 현재지도 위에 중첩하였다. 손가락 터치 검출은 열 적외선 카메라를 사용하여 손가락 접촉 후 생기는 잔류 열을 검출하였다. 손가락 접촉 위치는 검출된 잔류열을 이용하여 계산하였다. 현재 위성지도에서 특정 위치에 손가락을 터치하면 접촉한 위치를 계산하고 과거지도를 프로젝터로 투사하여 지도 조작이 가능하게 하였다. 제안하는 방법을 통해 구현된 인터페이스 시스템은 손가락 터치로 과거지도와 현재지도를 이해하는데 효과적으로 활용 될 수 있을 것으로 예상된다.

• Journal of Welding and Joining
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• v.16 no.5
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• pp.67-75
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• 1998

This study aimed at he experimental and finite element analytic investigation of the effect of preheating on he residual stress of weldment. In this study, an autogenous arc welding was used on type 304 stainless steel and MARC as F.E.M. common code was utilized in analysis The analyses include transient and moving heat source and thermal properties as function of temperature. During welding, the thermal cycles of four locations in the weldment were recorded to investigate of the behavior of thermal stress and residual stress. The experimental and analytic results had good coincidence and show that there are two factors influencing the formation of welding residual stress in preheat process. One is the elevation of welding equilibrium temperature and the other is the increase of amount of heat input. The former decrease welding residual stress and the latter increase welding residual stress. Therefore, the cumulative effects result in the welding residual stress not being improved significantly with preheating in 304 stainless steel.

• Journal of Welding and Joining
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• v.8 no.4
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• pp.76-82
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• 1990

Lots of research works have been done to improve the accuracy of the hole drilling method to measure residual stress by many investigators. In this study, first, size effect of specimen was analyzed based on the solution of hole in a strip under tension. If the ratio of hole diameter tothe strip width is less than 0.2, the stress distribution around hold may be given from the solution of hole in an infinite plate. Second, the residual stress above $0.6{\sigma}_y$(yield stress) may be measured less than the actual stress by 10-15 percent. Third, eccentricity of hole relative to the rosette center effects on the accuracy of residual stress measurements by 10 percent. The error due to eccentricity of hole can be corrected by the iteration method or the direct method.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.23 no.7 s.166
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• pp.1085-1093
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• 1999

Thickness effects of coupling agent on residual bending stress were investigated in $Polyimide/SiO_2$ joints during thermal cycling. Thickness and peel strength of $\gamma$-APS coupling agent were measured and correlated with solution concentration and residual bending stress. The variation of residual bending stress with temperature was also measured for various thicknesses of the coupling agent. Finite element results were compared with experimental data for residual bending stress in $Polyimide/SiO_2$ joints.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.311-316
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• 2008

Thick-walled cylinders, such as a cannon or nuclear reactor, are autofrettaged to induce advantageous residual stresses into pressure vessels and to increase operating pressure and the fatigue lifetimes. As the autofrettage level increases, the magnitude of compressive residual stress at the bore also increases. The purpose of the present paper is to predict the accurate residual stress of SCM440 high strength steel using the Kendall model which was adopted by ASME Code. Hydraulic pressure process was applied and thick-walled cylinders were autofrettaged up to 30% overstrain levels. Electro polishing was performed to get more accurate data. Residual stresses were measured by X-ray diffraction method. The autofrettaged surface which was plastically deformed analyzed using a scanning electron microscope(SEM). Although there were some differences in measured residual stress and numerical, there is a tendency to agree.

• The Journal of the Korea Contents Association
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• v.16 no.3
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• pp.328-334
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• 2016

This research is studied the systemic production method of missing teeth and ridge lap type pontic for the maintenance and restoration of normal function of the surrounding tissue as the goal of prosthetic treatment. According to the dentists' opinions, with the illustrated design criteria that pontic has to be equipped, inflammation, periodontal disease, food residues, and self-cleaning effect are obtained a better result than the conventional production method. The pontic production method presented in this paper is considered good enough to be applied to a clinically.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.3
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• pp.204-209
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• 2004

Using STD11 and STS3 as a mold set, accuracy of a mold product could be improved by heat treatment. Results of Charpy impact test and measurement of retained austenite in STS3 and STD11, STD11 was superior than STS3 in effect of sub-zero treatment and stability of working and measure. Decrease of retain austenite by sub-zero treatment in STS3 did not occured.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.457-458
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• 2000

Pefloxacine(PFX)은 기존 quinolone계 항균제의 단점을 보완한 fluoroquinolone계열의 합성 항균제로서 그람양성균과 그람음성균에 대해서도 살균효과가 뛰어날 뿐 아니라 내성균 출현 가능성이 비교적 낮은 장점이 있는 항균제로 보고되고 있다. 이러한 약리학적 특성 때문에 우리 나라에서도 양식어류 세균성 질병 치료제로 최근 사용량이 증가하고 있으나 현재까지도 어류를 대상으로 한 체내잔류 PFX의 정량분석방범과 PFX의 흡수, 분포, 해설 등 실제 약제 사용방법 설정에 필수적인 임상동태에 관해서는 연구가 되어 있지 않은 실정이다. 따라서 본 연구는 양식어류에 대한 PFX의 효과적인 사용방법을 확립하기 위하여 고속액체크로마토그라피(HPLC)를 사용하여 실험조건의 특이성 등을 검토하여 어체내 잔류 PFX의 최적 분석조건을 설정하였다. 그리고 주요 양식어류를 대상으로 PFX를 경구 투여한 후 시간경과에 따라 혈액을 채취하여 혈종에서의 약물동태학적 Parameter를 조사하였다. (중략)