• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.6
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• pp.30-36
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• 2014

Many different cells types have been found to be highly sensitive to mechanical force imposed by their surroundings. The cellular response to external mechanical forces has very important effects on numerous biological phenomena. In spite of its importance in biological processes, the cell adhesion force remains difficult to measure quantitatively at the cellular level. In this paper, to enhance quantitative measurements of cell adhesive interactions, a new attaching system and a method in which a glass bead can be attached to an AFM cantilever was designed and fabricated, and the degree of range displacement was controlled in the system. In an experiment, the movement of the stage in the attaching system and the attaching process were measured. The effectiveness of this system was confirmed as well in the experiment. In addition, through a commercial AFM system, the spring constant of the modified AFM probe could be measured.

• Journal of the Korean School Mathematics Society
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• v.7 no.1
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• pp.103-120
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• 2004

Today most of Korean students have no interest in mathematics and lack of confidence in it due to the burden of the college entrance examination, which often results in a failure or a dropout in mathematics in school. Therefore there is a need to diagnose the true causes and to find out a solution. As one of these solutions this study has developed and applied a learning model based upon cooperative group activities for the improvement of mathematical power to classroom. For developing this learning model a variety of research methods are used; questionnaires, observation, and analysis of the interview materials. After the application of this learning model, a lot of positive results in mathematics class have been observed.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.185-190
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• 2005

The shot peening process is often used to improve fatigue properties of metal parts. Among them, It is the most use in an auto-component. In order to achieve optimum, repeatable and reliable fatigue enhancement from the shot peening process, the important shot peening parameters must be controlled. In this paper, the optimum peening intensity (Almen intensity) condition is investigated by experiment. The Spur Gear steel was used to investigate shot peening effects. The fatigue life at $\sigma_a=1,050$ and $\sigma_a=1,250MPa$ first gently increases, then drops gently as peening intensity increases compared with unpeened specimen. Experimental results show that the optimum peening intensity range is $0.391\~0.434mmA$..So the fatigue strength and fatigue life have been tremendously increased by optimum-peening treatment. However, the fatigue strength and fatigue life have been decreased by over peeing.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.16 no.2
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• pp.196-201
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• 1994

One case of an unusual form of carcinoma involving the submucosal gland and duct of tongue was reported and reviewed. According to Gerughty et al(1968) four distinct component parts were classified : ductal carcinoma in situ(involvement of the ductal epithelium by in situ carcinomatous changes), squamous cell carcinoma, and a mixed carcinoma(combination of glandular and squamous characteristics and occasionally consisted of large nests composed of "glassy" cell). This tumor was fond to be extremely aggressive and highly malignant. The histopathologic features and the clinical behavior of this tumor were sufficiently distinctive to warrant the designation adenosquamous carcinoma : exhibit concomitant glandular and squamous neoplasm. The mode of therapy was evaluated and the treatment of choice appears to be radical surgery. So, we has done the radical neck dissection and partial glossectomy. However, the limited number of cases indicated that collection and subsequent analysis of additional cases must be performed before any definitive conclusion can be drawn.

• Journal of the Korean Magnetics Society
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• v.9 no.2
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• pp.85-90
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• 1999

The ferromagnetic resonance study of the magnetostatic wave modes for an YIG thin film, grown by a liquid phase epitaxy method, was performed by an FMR spectrometer at room temperature. The magnetostatic surface wave and backward volume wave modes show periodic excitations in parallel configuration, whereas the complex spectra were observed in perpendicular configuration. The resonance spectra in parallel configuration can be well explained by the Walker and Damon-Eshbach theory. The peak-peak line width of uniform mode was 0.4 Oe. The saturation magnetization $M_s$ of the YIG thin film was calculated as 137 emu/㎤. In order to know the dependence of the magnetostatic modes as a function of the saturation magnetization and the thickness, the (1,1) and (3,1) modes of the magnetostatic backward volume wave were compared and theoretically calculated.

• Journal of Periodontal and Implant Science
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• v.27 no.3
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• pp.515-524
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• 1997

헤민과 메나디온 제한에 의한 Porphyromonas gingivalis(P. gingivalis) W50의 병독력의 변화를 검색하고자, 실험관내 병독력을 NIH 3T3 세포의 세포활성 변화로 관찰하였고, 생체내 병독력은 배양상청액을 ICR mouse 피하조직에 주사한 후의 염증반응을 관찰하였다. 헤민 존재 하에 배양한 P. gingivalis W50 배양상청액에 의한 mouse 3T3 세포의 세포활성은 헤민과 메나디온 없이 배양한 세포의 활성보다 낮았다. 헤민과 메나디온을 첨가하지 않고 배양한 세균의 생체내 병독력은 중등도의 염증세포 침윤과 울혈에 의한 출혈, 미약한 세포간질의 부종과 근육 파괴를 보였다. 메나디온 존재 하에서 배양한 세균은 미약한 염증세포의 침윤, 울혈에 의한 출혈 및 근육의 파괴가 관찰되었다. 헤민 존재하에서 중등도의 울혈에 의한 출혈, 미약한 세포간질의 부종, 염증세포의 침윤 및 근육파괴가 관찰되었다. 헤민과 메나디온 존재 하에서 배양한 세균은 심한 염증세포의 침윤과 중등도의 세포간질의 부종 및 울혈에 의한 출혈을 보였다. 이상의 연구 결과 P. gingivalis W50 배양 상층액의 병독력은 헤민에 의하여 영향을 받는 것으로 생각된다.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.6
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• pp.105-112
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• 2013

Turbopump is typically an assembly of rotors and casings, and there are a number of joints between them. Every joint should be leak-proof, so there is always a seal to accomplish the goal. Among various seals, metal seals are advantageous in that they are robust at high pressure, and at wide range of temperature. In this study, flange joints using conical seal made of stainless steel, solid flat metal seal made of copper and metal C seal made of Inconel 718 were structurally designed and analyzed, considering both initial tightening and operating conditions.

• Journal of Aerospace System Engineering
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• v.11 no.6
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• pp.76-83
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• 2017

The MIL-STD-1553 standard has been used for over 40 years as a data bus technology for high-reliability mobile systems. However, 1 Mbps transmission speed is absolutely insufficient to implement sensor data convergence, which is an essential requirement of modern aerospace systems. In this paper, we analyze the hierarchical structure of the MIL-STD-1553B version specification and describe several methods to increase the transmission speed without losing the advantages of the existing MIL-STD-1553 bus. In addition, we analyzed the R & D cases of the high-speed MIL-STD-1553 technology, which have been conducted in leading aerospace countries.

• Journal of the Society of Naval Architects of Korea
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• v.36 no.4
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• pp.128-136
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• 1999

This paper suggests a new object-oriented methodology, ESBD(Evolutionary Simulation Based Design), for the development of an automated manufacturing system in shipbuilding. The target system, AHMS(Automated Hull-piece Manufacturing System), is a virtualized and distributed system controlling the manufacturing processes of storing, surface-pretreatment, cutting, 1st and 2nd curvature generation of material plates. The control and product-flow simulation is applied for the real-time product monitoring and product data management(PDM). The prototype system of AHMS also outlines the layout of the new automated factory.

• Journal of the KSME
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• v.31 no.4
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• pp.332-340
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• 1991

본 글에서는 속이 찬 실린더(solid cylinder)에서의 비대칭 탄성파전파 문제를 풀기 위한 해석적 방법의 일부를 소개하고자 한다. 속이찬 실린더에 있어서는 측면벽의 경계조건에 상관없이 평 판에서의 Fourier 시리즈와 유사한 단순해가 존재하지 않는다고 밝혀져 왔다(1). 그러나 최근 발표된 본인의 논문(2)에서 지적된 것처럼, 매우 특별한 측면 경계조건을 갖는 경우에만 정해가 존재한다. 특히 탄성파전파에 관한 한, 이러한 정해는 물리적으로 볼 때 팽창파(dilatational wave)와 전단파(shear wave)가 서로 얽히지 않는 상태에 해당되기 때문에, 소위 "비혼합 해(uncoupled solution)"라 불린다. 이 "비혼합해(uncoupled solution)"의 실제 사용 예를 들면, 상술된 바와 같이 일반적인 측면 경계조건을 갖는 속이 찬 실린더 문제를 풀기 위한 시도함 수(trial function)로 사용될 수 있을 것이다. 주지하는 바와 같이 자유측면벽(traction-free cylindrical wall)을 갖는 속이 찬 실린더는 공학적으로 매우 중요한 구조요소이다. 이 경우에는 측면벽의 경계조건으로 말미암아, 해가 정해의 형태로 존재하지 않는다. 특히 이 구조물에서의 탄성파전파 문제를 다루고자 할 때, 먼저 분산관계식(dispersion relation)을 구한 다음, 이를 이 용해 경계문제를 푸는 것이 상용적으로 사용되는 방법이다. 이 분산 관계식은 파장과 주파수 와의 관계를 나타내는 것으로, 그 복잡성으로 말미암아 이 식을 사용되는 수치해법으로 정확하게 구하는 것은 거의 불가능하다. 따라서, 본 글에서는 특별한 측면벽을 갖는 속이 찬 실린더의 비혼합해를 활용하여 자유측면벽을 갖는 속이 찬 실린더의 분산관계식(pochhammer의 분산관 계식이라 불린다)을 구하는 법을 설명하고자 한다. 이를 위해 비혼합해가 존재하는 측면경계조 건에 대해 먼저 살펴보고자 한다.조 건에 대해 먼저 살펴보고자 한다.