• Journal of the Society of Naval Architects of Korea
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• v.30 no.1
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• pp.134-144
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• 1993

Sandwich plate is consisted of equal two isotropic, thin, stiff and strong sheets of dense material separated symmetrically by an isotropic thick layer which may be much less stiff and strong. This study analyzed the dependency of the natural frequencies and mode shapes of sandwich plates on material properties, thicknesses of faces and cores, and various boundary conditions using Rayleigh-Ritz method. E-glass Woven Roving and another two kinds of materials were selected as a face, P.V.C. and another kinds of materials were selected as a core. Natural frequencies and mode shapes obtained by Rayleigh-Ritz method were compared with F.E.M. solutions using ADINA program.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1991.10a
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• pp.357-365
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• 1991

Military material-supply problem is one of the most important logistic problems under conscription system. Formally, two approaches were followed lowed to this problem. (1) Needs for material per soldier is estimated by past experience. The total demand for the material is estimated by multiplication of this coefficient and the number of soldiers given in the governmental programme. (2) The total demand for the material is estimated by the forcast based on the past statistics. The material supply system based on these estimates, however, relies too much on past statistics ;lack of flexibility is feared to adapt itself to changes in conscription programme, life-time of materials and so on. In this paper, the author has followed new approach : The conscription system itself is a linear input-output system, in which sequences of enlistment and dischargement are regarded as input and output. And the sequencial demands for the material are related by another linear transformation to the former sequences. In this regard z-transformation is applied to construct to transfer functions associated with this system. With these transfer functions, methods are established to determine the material demand corresponding to conscription programme and life-time distribution. Numerical methods by computers are also prepared.

• Computers and Concrete
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• v.3 no.4
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• pp.197-212
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• 2006

Modeling of physically non-linear behavior becomes more and more important for the analysis of SFRC structures in practical applications. From this point of view we will present an effective, three-dimensional constitutive model for SFRC, that is also easy to implement in commercial finite element programs. Additionally, the finite element analysis should only require standard material parameters which can be gained easily from conventional experiments or which are specified in appropriate building codes. Another important point is attaining the material parameters from experimental data. The procedures to determine the material parameters proposed in appropriate codes seem to be only approximations and are unsuitable for precise structural analysis. Therefore a finite element analysis of the test itself is used to get the material parameters. This process is also denoted as inverse analysis. The efficiency of the proposed constitutive model is demonstrated on the basis of numerical examples and their comparison to experimental results. In the framework of material parameter identification the idea of a new, indirect tension testing procedure, the "Modified Tension Test", is adopted and extended to an easy-to-carry-out tension test for steel fiber reinforced concrete specimens.

• Journal of Korea Multimedia Society
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• v.7 no.12
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• pp.1700-1707
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• 2004

Nowaday, market size of digital image in world around is looks to rapidly growth. For this, Texture mapping has traditionally been used to add realism to computer graphics images. Therefore to make our image realistic, we need to give the various kind of objects material parameter and environment lighting. To present the completed marble we use passing back algorithm and combination with channel of a material. In experimental result of this paper that application by passing back algorithm and varying the parameter such as scale, period, distortion, octaves of noise make showing the superiority of optimized rendering of spheres and perfect another marble effects.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.563-566
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• 2006

In this paper, we studied about AGVs modeling and material handling automation simulation using a virtual AGV. The proposed virtual AGV model that operates independently each other is based on a real AGV. Continuous straight-line and workstation model using vector drawing method that could easily, rapidly work system modeling are suggested. Centralized traffic control, which could collision avoidance in intersection and should not stop AGV as possible, and algorithm for detour routing which performs when another AGV is working in pre-routed path are proposed. The traffic control and the algorithm have been proved efficiently by simulation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.127-131
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• 2008

This paper deals with the performance evaluation of piezoelectric unimorph actuator. In the unimorph design, the thickness ratio of substrate to piezoelectric material and the elastic modulus ratio of substrate to piezoelectric material are important parameters. There exists only one structural configuration that satisfies the optimal condition among them, and actuators using that configuration exhibit better actuating displacements. Another design parameter is the piezoelectric coefficient which can be improved due to the induced tensile stress and voltages. The application of the tensile stress to the piezoelectric material makes it get higher piezoelectric coefficient and the total displacement performance of the unimorph actuator is improved. Finally, the piezoelectric actuator system with spring elements is fabricated and it shows higher actuating displacement capability.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.12
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• pp.1341-1346
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• 2004

The OLED research is gone for two directions. One is material development research, and another one is structural improvement part. All two are thing to heighten luminescence efficiency of OLED. n other to improve luminescence efficiency of OLED Electron - hole pairs must consist much more in the device Their profiles are sensitive to mobility velocity of electrons and holes. In this paper, we demonstrate the difference of velocity between hole and electron by experiments, and compare with a data of simulation and experiment changing hole carrier transport layer thickness, so we get the optimal we improve luminescence efficiency. We suggest improving the efficiency of OLEDS would be to balance the injection of electrons and holes into light emission layer of the device. And, we improve understanding of the various luminescence efficiency through experiments and numerical analysis of luminescence efficiency in variable hole carrier transport layer's thickness.

• Journal of the Korea Furniture Society
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• v.24 no.3
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• pp.263-272
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• 2013

This study is the content of the environment-friendly is the tendency of one of postmodernism. Rather than end up post-modernism in the past, such trend has affected many in the design of modern furniture. Appeal to emotion in order to achieve an intimate relationship with the user, especially in the new material, you are the fulfillment of desire more than a simple function. In addition, designers of modern Many or even looking from the re-interpretation of the design past the motif of the design such as the time that post-modernism has arrived. Users who are using the furniture, because there is a tendency to features In addition to the primary that it has, you have to Want the meaning of one another, and to Serve by generating story distance from him this some. In this study, to target households that still is very important in modern design, and a historic of postmodernism the concept with a different meaning functional, the figurative to break free from meaning one-dimensional with the furniture I was analyzed on the basis of the flow.

• Journal of Korean Library and Information Science Society
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• v.28
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• pp.219-262
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• 1998

For many years art libraries have been concerned about the problem resulting from the addition of exhibition catalogs to general art collection. Those who work or research in the art field agree that exhibition catalogs are great value, and in many cases, the essays and documentary material contained in these catalogs may be the only source of information on particular artists. This paper contains two purposes. One is to settle the exhibition catalog as a specific form of publication in the library. In theoretical aspect, this material is handled in definition, form, historical development and the position and specification. Another is to manage exhibition catalog in the library. In practical aspect, this material is handled in aquisition, classification, cataloging and use.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.175-176
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• 2016

In this study, research is in order to prevent the defects that occur when the polished tiles construction. For material to be used when the polishing tile construction, trying to evaluate the shrinkage characteristics when the environmental conditions change. Depending on the material used for the shrinkage characteristics evaluation results, the difference between the change values of the length of the drying shrinkage becomes large. Therefore, there is a need for the construction method with consideration of the characteristics of the materials used.