• 한국안전학회지
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• 제7권1호
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• pp.65-72
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• 1992

Objective of this research is to evaluate fracture behaviors of fresh-butt welded metal by the acoustic emission technique. The specimens used are medium carbon steel(SM45C), mild steel (SS41) and stainless steel(SUS304), which have different weldability. The similar welding and dissimilar welding processes are considered, in the former SM45C, SS41 and SUS304 are used, in the later the following metals are used SM45C and SS41, SM45C and SUS304 and SS41 and SUS304. The characteristics of fracture in weld metal are eshmated by the tension test with nominal speciemns, the fracture toughness test with compact tension specimens and fractography analysis. The results of tension test show for base metals and similar welding materials that the yield strength and ultimate strength of similar welding materials are increased, the elongation of those are decreased. The weldability of SUS304 is better than that of SM45C and SS41 In similar welding materials. Mechanical properties of dissimilar welding mateiiths we lower than those of similar welding materials. In dissimilar welding materials, the weldability of SM45C and SUS304 is better than that of SM45C and SS41, and also weidability of SS41 and SUS304 is better than SS41 and SM45C. Comparing mechanical properties with AE counts, it is found that AE conuts appeared on a small before the limit load of elasticity(P$_{e}$), and apper greatly near yield strength region in tension test. These results could contribute to the safety analyses and the evaluation of strength for welding structure.e.

• 한국전기전자재료학회논문지
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• 제35권3호
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• pp.255-263
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• 2022

The subthreshold swing (SS) of an asymmetric junctionless double gate (AJLDG) MOSFET is analyzed by the use of Gaussian function. In the asymmetric structure, the thickness of the top/bottom oxide film and the flat-band voltages of top gate (V_fbf) and bottom gate (V_fbb) could be made differently, so the change in the SS for these factors is analyzed with the projected range and standard projected deviation which are parameters for the Gaussian function. An analytical subthreshold swing model is presented from the Poisson's equation, and it is shown that this model is in a good agreement with the numerical model. As a result, the SS changes linearly according to the geometric mean of the top and bottom oxide film thicknesses, and if the projected range is less than half of the silicon thickness, the SS decreases as the top gate oxide film is smaller. Conversely, if the projected range is bigger than a half of the silicon thickness, the SS decreases as the bottom gate oxide film is smaller. In addition, the SS decreases as V_fbb-V_fbf increases when the projected range is near the top gate, and the SS decreases as V_fbb-V_fbf decreases when the projected range is near the bottom gate. It is necessary that one should pay attention to the selection of the top/bottom oxide thickness and the gate metal in order to reduce the SS when designing an AJLDG MOSFET.

• IMMUNE NETWORK
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• 제19권1호
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• pp.7.1-7.11
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• 2019

Sjögren's syndrome (SS) is a chronic inflammatory autoimmune disorder that affects mainly salivary and lacrimal glands, but its cause remains largely unknown. Clinical data indicating that SS occurs in a substantial proportion of patients with lupus points to common pathogenic mechanisms underlying the two diseases. To address this idea, we asked whether SS develops in the lupus-prone mouse strain sanroque (SAN). Owing to hyper-activation of follicular helper T (Tfh) cells, female SAN mice developed lupus-like symptoms at approximately 20 wk of age but there were no signs of SS at that time. However, symptoms typical of SS were evident at approximately 40 wk of age, as judged by reduced saliva flow rate, sialadenitis, and IgG deposits in the salivary glands. Increases in serum titers of SS-related autoantibodies and numbers of autoantibody-secreting cells in cervical lymph nodes (LNs) preceded the pathologic manifestations of SS and were accompanied by expansion of Tfh cells and their downstream effector cells. Thus, our results suggest that chronic dysregulation of Tfh cells in salivary gland-draining LNs is sufficient to drive the development of SS in lupus-prone mice.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 춘계학술대회 논문집
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• pp.1115-1116
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• 2012

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 추계학술대회 논문집
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• pp.687-688
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• 2012

• 센서학회지
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• 제22권1호
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• pp.84-88
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• 2013

In this paper, the low price signal generator with capability of frequency high-resolution and variable sync pulse has implemented. It fulfils well the requirements for SS-OCT of the frequency resolution less than 1Hz, frequency stability of ${\leq}{\pm}0.5Hz$/10 min and variable sync pulse output timing. Through its performance test applied to wavelength swept laser, 120 nm sweeping range and 10 mW average optical power were obtained. This shows that the realized sine-wave generator can replace the commercial high cost and high performance signal generators employed by current SS-OCT systems.

• 통합자연과학논문집
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• 제9권2호
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• pp.136-143
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• 2016

KiSS1-derived peptide receptor, a GPCR protein, binds with the hormone kiss peptin. They are important in the neuroendocrine regulation of reproduction and in the secretion of gonadotrophin-releasing hormone. Thus, analysing the structural features of the receptor becomes important. However, the three dimensional structure of the protein is unavailable. Hence in this study, we have performed the homology modelling of KiSS1-derived peptide receptor with 5 different templates. 30 models were constructed using two platforms - Easymodeller and ITasser. The optimal models were chosen based on the model validation. Two models were selected after validation. The developed models could provide useful for analysing the structural features of KiSS1-derived peptide receptor and their pathophysiological role in various disorders related to them.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1952_1953
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• 2009

전력선 채널 잡음은 전력선에 연결되어 있는 전기기기들에 의하여 변화하는 특성을 갖으며, 이러한 잡음 특성을 극복하기 위한 한가지 방법으로 DS/SS 방식을 적용하는 방법이 있다. 그러나 저속 DS/SS 전력선 모뎀의 경우 낮은 데이터전송률 때문에, 잡음 특성을 개선하기 위하여 Chip 수가 큰 PN code를 적용하기 어렵다. 따라서 본 논문에서는 전원 전압에 동기되어 잡음의 양이 변화하는 것에 따라 PN code를 변경하는 방법[1]을 적용하고자 하였다. 전력선 채널의 잡음은 비교적 부하가 고정적인 가로등 전력선 채널로 한정하여 잡음을 모델링 하였으며, 전원전압에 맞추어 잡음의 양에 따라 PN code 길이를 변경하는 FSK 방식의 DS/SS 시스템을 구성하여 시뮬레이션 하였다. 시뮬레이션 결과 적용된 시스템이 전력선 채널에서 효과적 성능을 발휘함을 확인하였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1787-1791
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• 2007

For structural design and diagnosis, quantitative relationship between corrosive degradation and variation of mechanical properties such as tensile strength and fatigue strength is needed. But it is difficult to find data associated with corrosive degradation of structural structures. In this study, first of all we established the atmospheric corrosion test procedure. And using specimens of SM490A and SS400 on the atmospheric corrosion test bed, we carried out tensile and fatigue tests at regular intervals. And we studied the effect of post-weld heat treatment on the tensile and fatigue behaviour. It is found fatigue strength decreases as the atmospheric corrosion period increases.

• 한국산업융합학회 논문집
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• 제3권1호
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• pp.77-82
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• 2000

The stereoselective ligand exchange reaction of trans-$[Co(SS-epm)Cl_2]^+$ and racemic propane-1,2-diamine (rac-pn) produces the complex that is identified as $[CO(N)_6]^{3+}$ type of $[Co(SS-epm)(pn)]^{3+}$ by absorption spectrum. It is conceivable that the reaction mechanism involves substitution and isomerization. The calculated and experimentally determined ratios of the complexed enantiomeric substrates at equilibrium were as follows: $[Co(SS-epm)(pn)]^{3+}$,calcd 32 % / 68 %, exptl 19 % / 81 % R-pn / S-pn. It has been shown that the employment of molecular mechanics calculations as a predictive tool may lead to the design of chiral complexes that may be applied to the separation of racemic mixtures of simple bidentate ligands.