• 한국인쇄학회지
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• 제30권2호
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• pp.59-68
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• 2012

As one of the eletronic device industries has been developed by using a recent printing method, the consumption of Ag paste has been on the rise as well. The printing method has simple processes in comparison with other methods. Also it enables to be large-scaled and to lower price ranges. If UV curing system would be applied to the printing method, energy consumption and dangerousness from curing system can be minimized in a short period of time so that its method can be more eco-friendly. This study conducted an experiment in order to make UV curing Ag paste which is feasible to implement micro patterns with different dispersing agents. The purpose of the study is to analysis the suitable printability for micro pattern and to test dispersibility, hardening properties, conductivity and adhesive stength by measuring viscosity, TI(thixotropy index), G', G", $tan{\delta}$(G"/G') after making paste. We have experimented with four dispersing agents. After We did an analysis of characteristic of rheology, conductivity and adhesive stength, etc, We confirmed that the paste added FP 3060 has excellent dispersibility, conductivity and adhesive stength. If the paste has excellent dispersibility, we will expect that micro pattern is made by that.

• 한국강구조학회 논문집
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• 제14권3호
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• pp.453-461
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• 2002

본 연구에서는 고강도 강재인 SM570강재와 POSTEN80강재로 제작된 하중비전달형 십자용접연결부의 피로특성을 평가하는 것으로 대상강재의 피로강도, 피로균열의 발생과 진전, 판두께효과, 정적강도와 피로강도와의 관계를 기존의 연구결과와 비교, 분석하였다. SM570강재와 POSTEN80강재의 피로강도는 설계지침에 제시된 등급보다 높은 것으로 나타났으며 판두께효과 및 일부의 경우에 있어 정적 강도 의존성을 확인하였다.

• 레미콘
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• 7호통권72호
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• pp.29-41
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• 2002

The purpose of this study is to investigarte the mix design method and the mechanical properties of High stength Lightweight Concrete (HSLC). In the experment, concrete mixing was conducted to select the optimum mix design for HSLC in laboratory. Also, concrete mixing in ready mix design. As a result, it is possible to establish the mix design of HSLC according to the using these experimental results ;the estimate equation for unit weight of HSLC. the relationship between W/C and compressive strength of HSLC and the fluidity of HSLC in the view of workability

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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• pp.429-432
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• 2006

The shrinkage mechanism of high strength concrete is different from that of normal concrete. The shrinkage of normal concrete is subjected to evaporate moisture in concrete, but most shrinkage in high strength concrete is caused by chemical reaction. To analyze shrinkage of concrete exactly, it is necessary to divide drying shrinkage with autogenous shrinkage in terms of degree of hydration, especially in concrete with low W/C ratio. The proposed method can provide a rational basis for prediction of shrinkage in high strength concrete structure.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 추계학술대회 논문집 학회본부
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• pp.189-192
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• 1991

This paper presents a modular structure design of analog Hopfield neural network. Each multiplier consists of four MOS transistors which are connected to an op-amp at the front end of a neuron. A pair of MOS transistor is used in order to maintain linear operation of the synapse and can produce positive or negative synaptic weight. This architecture can be expandable to any size neural network by forming tree structure. By altering the connections, other nework paradigms can also be implemented using this basic modules. The stength of this approach is the expandability and the general applicability. The layout design of a four-neuron fully connected feedback neural network is presented and is simulated using SPICE. The network shows correct retrival of distorted patterns.

• 터널과지하공간
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• 제3권2호
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• pp.132-141
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• 1993

Laboratory and field tests were performed to find out the effectiveness of ground improvement by grouting for an urban subway tunnel that was excavated in weak rock by the NATM. Field measurements were carried out to monitor the behavior of rock mass around the tunnel and to ensure the validity of the current design of the distance form the measuring points to the tunnel face. The final converged displacement and the peroid were predicted using the gamma function. It was found that the ground improvement in terms of reduced permeability and increased stength in the self-supportability of the excavation face enabled the NATM applied in poor gorund. As the result of applying the gamma function to the predicting of displacement, the final displacement including the preceding one and the converged period could be approximately predicted at the early excavation stage.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1995년도 봄 학술발표회 논문집
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• pp.331-338
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• 1995

Results of an experimental of the shear and flexures strength of doubly reinforced concrete beams were summarized. A total of 24 beams was tested; 4 without web reinforcement and 20 with web reinforcement in the form of vertical stirrups. Main variables were compressive strength of concrete which was 26.88MPa and 63.4MPa, spacing of stirrups which was no-stirrups, 200, 150, 120, 100 and 90mm. Tests results were compared with stength predicted using the equations of ACI 318-89. The shear reinforcement ratio of the beams, which failed simultaneously under both flexures and shear, were 0.66pvmax for low strength concrete beams and 0.56pvmax for high strength concrete beams, respectively. Thus, ACI equations for shear reinforcement were very conservative.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2005년도 추계 학술대회논문집
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• pp.141-144
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• 2005

The fluid-structure interaction analysis such as a static aeroelastic analysis requires the result of each analysis as an input to other analysis. Usually the grids for the fluid analysis and the structural analysis are different, so the results should be transformed properly for each other. The Infinite Plate Spline(IPS) and the Thin Plate Spline(TPS) are used in interpolating the displacement and the pressure. In this study, such interpolation methods are compared with kriging which provides a precise response surface. The static aeroelastic analysis is performed for the supersonic flow field with shock waves and the pressure field is interpolated by the TPS and kriging. The TPS shows tendency to weaken the shock stength, whereas kriging preserves the shock strength.

• 열처리공학회지
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• 제17권2호
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• pp.73-77
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• 2004

The efforts which increase the strength of the auto-body structure and decrease its weight lead to develop a new concept of part production systems, such as Post-Form Strengthening by induction heat treatment. In this study, several cold and hot-rolled sheet steels were used to find out optimum induction heat treatment conditions. After induction heat treatment, strength of heat-treated sheet steels was increased significantly compared with that of as-rolled steels. From these results, auto-body structure which has more light and safe has been made by using this induction hardening method.

• 경영과학
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• 제16권1호
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• pp.173-186
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• 1999

Recently many firms are introducing the cellular manufacturing system(CMS) as a means of achieving manufacturing efficiencies. However, most of the research on CMS was mainly for determining the cell formation problems. Since the goal of the CMS is not only a increase production efficiencies, but also to enhance the competitive stength of a firm, it would be reasonable to assume CMS as a business reengineering module rather than an independent technique. The purpose of this study is to align the CMS with reengineering, to present an integrated methodology for constructing the CMS, and to apply the CMS to a firm and verify it. The paper concludes with a brief description of the lessons learend by the CMS project and the limitations of the research are described.