• Composites Research
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• v.24 no.4
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• pp.41-47
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• 2011

This paper deals with anisotropic property and structural analysis for short fiber reinforced plastic composites manufactured by the injection molding process. The common approach for modeling this type of material is the consideration of the material as homogenous and isotropic. However, the common isotropy approach often results in unexpected failure. To overcome this, new structure analysis methodology was developed in order to consider fiber orientation effect using injection mold flow analysis and Halpin-Tsai equations for unidirectional composites and taking an orientation average. The numerical predictions are compared to experimental data for tensile specimen. The predicted mechanical properties agree well with experimental data for fiber orientation and weld line effect. The analysis system was also applied to an automobile part. The proposed anisotropic model predicted different mechanical properties by position of the part and different mechanical performance of the part was changed according to injection gate position.

• Archives of design research
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• v.16 no.3
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• pp.281-290
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• 2003

An educational practice is a communicational course between educator and student with scheme and execution of studying. The communicational contents of the practical course require teaching transmission and recipient process for educator and student as a major knowledges end techniques in order to achieve student's aim. The communication of practical course consists of educators, students, and practical contents, and they also form both meaning objects and mutual relationships for constitution of the practical courses. In order to develop the effective plan for practical process, we have to understand the phenomena of meaning operations which consists in connections of the practical exercise and the meaning object. This study is to approach a phenomenal analysis as respects the meaning operations how forms of tie meaning object exert in the practical course. On the basis of this analysis, we grasp properties of the practical course into the meaning object, and in these connections, suggest the category of cognizance to put execution in the practical course by interpreting factors of the meaning operations.

• Proceedings of the Korea Society of Design Studies Conference
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• 2004.10a
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• pp.234-235
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• 2004

현재 자동차의 변화를 이끄는 흐름에서 가장 핵심이 되고 있는 유형 Sport Utility Vehicle은 전천후 기동성 측면과 Sports성을 중심적인 특성으로 다루고 있다. 그러나 SUV로서 off road 중심의 공간 활용 보다는 실내 공간 중심의 활용이 더욱 중요한 특성으로 자리잡고 있다. 이러한 경향은 주 5일 근무 정착에 따른 여가 시간의 증가와 아울러 보다 다양한 직업과 생활 패턴 등에 따라 더욱 두드러질 것으로 보인다. 이러한 근 미래 변화에 대응하는 방법으로 기존의 SUV type에서 탈피하여 sports성을 반영하는 동시에 보다 utility적 활용 중심의 특성을 가지는 XUV (eXtreme Utility Vehicle)라는 새로운 유형을 2010년 시점의 근 미래 테크놀러지와 조형성의 동향 예측, 사용자 요구점 분석 포지셔닝 등을 통해 제안한다.

• Korean Journal of Head & Neck Oncology
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• v.28 no.2
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• pp.107-113
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• 2012

배 경 편평상피암은 두경부의 악성종양 중 가장 흔하며, 임상적인 경과가 불량하다. 따라서 나쁜 예후를 가지는 환자군을 조기에 선별하여 더 적극적인 치료의 시행을 결정짓는 표지자의 필요성이 대두된다. 우리는 일련의 두경부 편평세포암 검체에서 몇몇 분자 표지자의 예후적 유용성을 평가하고자 하였다. 방 법 23예의 두경부 편평세포암 검체를 대상으로 VEGF, p53, Apaf-1, caspase-9의 발현과 몇몇 임상병리학적 지표들간의 연관성을 면역조직화학염색을 통해 조사하였다. 결 과 환자군은 남성이 더 많았으며 평균연령은 63.7세였다. 1기가 5예, 2기가 2예, 3기가 8예, 4기가 8예였다. 평균생존기간은 37.3개월이었다. VEGF단백 발현은 종양의 크기와 통계적으로 유의한 연관성을 보였다. 이와 더불어 VEGF단백 발현은 병기, 그리고 림프관 침습과 연관적인 경향성을 보였다. 그러나 VEGF단백 발현과 생존기간과는 관련성이 없었다. 또한, Apaf-1과 caspase-9의 단백발현은 다른 임상지표, 환자의 생존기간과는 관련이 없었다. 결 론 VEGF단백 발현은 두경부 편평세포암 환자에서 나쁜 임상경과를 예측할 수 있게 하는 표지자로서의 역할을 할 수 있다. 또한 본 연구는 두경부 편평세포암에서 별로 연구되지 않은 Apaf-1과 caspase-9의 발현상태를 밝힌 점에서 의의가 있다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.4
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• pp.82-91
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• 2003

Experiments to investigate the mixing performance of unlike doublet impinging jets are conducted. Reynolds number of simulants used in this study rages from 1.0 to 1.5 Cold flow test is performed to investigate the hydrodynamic effect and spray of the impinging jets are collected locally and calculated by using Rupe's mixing efficiency equation. Momentum exchanges and relative velocity ratio between two jets are taken as the main parameter to represent the effect of enlargement of the orifice diameter. As diameter ratio increases, the corresponding momentum ratio where maximum mixing efficiency occurs and relative velocity at the maximum mixing efficiency ranges 0.6 to 0.7, respectively. Penetration depth can be taken as a prominent parameter to estimate the mixing efficiency.

• The Journal of the Korea Contents Association
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• v.17 no.6
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• pp.272-286
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• 2017

The division of the South and North of 70 years has occurred in the old generation, but the reunification is now handled by the youth generation. Therefore, it is necessary to train basic human nature as well as learning and research of rational political and economic theory in order for young adolescents as leaders in the unification era to carry out their own duties faithfully and responsibly. In this paper, I rediscover the value of traditional culture in the human nature education that aims for reunification, social and cultural integration, and propose tea culture as contents that can be applied to reunification and the human nature education of youth as reunification culture contents as a concrete program of traditional culture do.

• Journal of Welding and Joining
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• v.33 no.2
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• pp.56-61
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• 2015

IRW(Inverter Resistance Welding) process and DSW(Delta-spot welding) process for dissimilar materials of DP590 and Al5052 were performed to evaluate the welding quality and mechanical properties. IRW experiment was carried out with changing the welding current. The other welding parameters such as pressure force, weld time, squeezing time and holding time were fixed. On the anther hand, DSW experiment was performed using the process tape at welding current of 11.5kA. The other conditions were same as IRW conditions. The various testes such as shear tensile strength, nugget diameters, EDS, SEM and cross-sectional observation for weld zone was performed. As a result, IMC(Inter Metallic Compound) thickness at 11.5kA was thinner than those of 9.5kA and 10.5kA conditions. In addition, thined IMC layer was observed when high electric current apply to the materials(DP590 and Al5052) in a short time throught dissimilar resistance spot welding controling welding conditions. The relationship between the thickeness of IMC and current intensity was after discussed.

• Polymer(Korea)
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• v.26 no.3
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• pp.307-315
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• 2002

Major factors affecting the impact resistance of high impact polystyrene (HIPS), the rubber-toughened grade of polystyrene, are rubber-phase particle size and size distribution, molecular weight, morphology, and degree of grafting. Accordingly, it is important to control or investigate these factors. In this study, the effect of solvent content was analyzed by the morphology and particle size distribution of rubber phase, and final properties in bulk-solution polymerization of HIPS. The prepolymerization time was, first, determined by measuring the evolution of particle size distribution of dispersed phase to explain the phase inversion with time. As the solvent content increased, the size of rubber particle increased and then gradually decreased. Rubber-phase morphology was likely to have higher degree of grafting as the solvent content increased. Rheological and mechanical properties decreased as the solvent content increased because of the decrease of matrix molecular weight due to the chain transfer reaction to solvent and the existence of residual solvent. Nevertheless, the impact resistance seemed to increase when the rubber particle size increased.

• The Korean Journal of Mycology
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• v.30 no.1
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• pp.31-36
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• 2002

Since lectin condense more easily cancer cell than normal cell, it has been investigated very actively. Recently, a lot of researchers gave attention to lectin in natural products especially because lectin has effects on T-cell activation and anticancer activity, and specificity on polysaccharide. The specificity is useful to confirm kind of polysaccharide of the cell surface and to study the polysaccharide. In this research, we purified lectin from shiitake, Lentinula edodes, and then characterized it. The molecular weight of the lectin was 23 kDa, and it was stable only under the $40^{\circ}C$ and in a alkaline solution. As for the specificity of polysaccharide, the lectin had specificity on galactose, fucose, glucose, lactose and N-acetyl-D-galactosamine. In addition, it was confirmed to be a glycoprotein.

• The Journal of the Acoustical Society of Korea
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• v.8 no.5
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• pp.102-112
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• 1989

In this paper, we proposed the study on speaker-independent isolated word recognition for DDD area-name using vector quantization and chose total 146 DDD area-name to recognize words for application of dialing system. We made the codebook using 12th LPC cepstrum coefficients and used the minsum and the minimax method to find the centroid and we applied 3 splitting rule to a codebook generation. The single section and the multi section with time information were used to generate the codebooks and the over-lapped section codebook was used, too. From the experiment result, we proved that the minsum method was better than the minimax method and the evaluation of the system yielded an accuracy of about 90 percents In case of speaker-independent.