• 한국자동차공학회논문집
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• 제4권4호
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• pp.147-155
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• 1996

The purpose of present paper is to estimate the static and fatigue bending strengths of CFRP(carbon fiber reinforced plastic) laminates having impact damage(FOD). The specimens which are formed with the different stacking composition, EPOXY and PEEK matirx and orthotropic and quasi-isotropic laminated plates, are prepared for this experiment. A steel ball is impacted on CFRP laminates, generating impact damages, and the three-point fatigue bending test is carried out by using the impacted laminates to investigate the influence of the stackin composition on the fatigue strength of CFRP laminates.

• 분석과학
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• 제5권2호
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• pp.203-211
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• 1992

Ni-36.5at.%Al 합금에서 결정립계에서의 scavenging 원소로 알려진 V를 첨가하여 이 합금의 파괴거동 및 마르텐사이트 미세조직에 미치는 V의 영향에 대해 조사하였다. 시편의 파단면은 주사전자현미경으로 관찰하였고 EDX spectrometer를 사용하여 파단면의 조성을 분석하였으며 투과전자현미경으로 마르텐사이트 내부조직의 변화에 대해 조사하였다. V의 첨가로 입계파괴에서 입내파괴로 파괴 모드의 변화를 나타내었으며 EDX spectrometer로 분석한 결과 입내에 비해 입계에 Al의 함량이 상대적으로 증가되는 양상을 보여 주었다. Ni-36.5at.%Al 합금의 경우 마르텐사이트 플레이트는 내부쌍정으로 이루어져 있으나 V의 첨가에 따라 twinned 마르텐사이트 조직은 사라지며 stacking fault와 고밀도의 전위를 가진 modulated 조직이 점차 지배적으로 형성되는 것이 관찰되었다. Stacking fault를 분석한 결과 Al과 V의 치환에 따른 extrinsic fault였으며 high-energy 상태인 이 stacking fault가 있는 부위에 유해 원소인 S가 편석됨으로써 결정립계에서의 파괴를 줄일 수 있었다.

• 한국실내디자인학회논문집
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• 제26권6호
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• pp.62-70
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• 2017

This study has a purpose that definitize correlationship of spatial structure and sales strategies in mixed-use complexes which established in Korea since year 2000. For this purpose, this study tries to analysis spatial structure of mixed-use facilities through space syntax theory and makes an typological categorization based on their space composition. As a result of categorization, Korean mixed-use facilities can be classed as three types. First type is integrated stacking type. Second one is parallel connecting type. Third type is room to room type. According to differences between categories, their spatial structures show different meaning with different sales strategies. Integrated stacking type sales luxury brands and expensive stuffs and it also has deep and complicated structure. That means theses spaces usually make a strategy of exclusion. Parallel connecting type sales special categories and it also has shallow and easy spatial structure. That means these facilities want to make a smooth connection between apposed volumes. Room to room type sales cheap and fancy objects and it also has simple and shallow structure. That means simple spatial structure can be lead contact customer to stuffs. These results mean spatial structure have a effect on design of sales space.

• Advances in materials Research
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• 제12권1호
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• pp.67-81
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• 2023

Basalt and poly-ester fibers along with epoxy resin were used to produce inter-ply, intra-ply and functionally gradient hybrid composites. In all of the composites, the relative content of basalt fiber to poly-ester fiber was equal to 50 percent. The flexural and charpy impact properties of the hybrid composites are presented with particular regard to the effects of the hybrid types, stacking sequence of the plies, loading direction and loading speed. The results show that with properly choosing the composition and the stacking sequence of the plies; the inter-ply hybrid composites can achieve better flexural strength and impact absorption energy compared to the intra-ply and functionally gradient composites. The flexural strength and impact absorption energy of the functionally gradient hybrid composites is comparable to, or higher than the intra-ply sample. Also, by increasing the loading speed, the flexural strength increases while the flexural modulus does not have any special trend.

• 한국세라믹학회지
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• 제29권9호
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• pp.695-704
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• 1992

In (Pb, La)(Zr, Ti)O3 ceramic system, the functionally gradient material (FGM) was developed, and its processing and properties were investigated. The FGMs were successfully prepared through doctor blade method with acrylic binder system as well as mold stacking press method. The ultrasonic treatment was very effective for particle dispersion in slurry, and it lead to form clack-free green films. The strain-voltage characteristics of the FGM system was significantly improved which fabricated between a high piezoelectric-low dielectric and a low piezoelectric-high dielectric composition layer.

• 한국안전학회지
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• 제12권2호
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• pp.27-36
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• 1997

This paper evaluates the static and fatigue bending strengths of CFRP (carbon fiber reinforced plastic) laminates subjected to hygrothermals. The specimens which had different stacking composition, orthotropic and quasi-isotropic laminated plates, were prepared for this experiment. A steel ball launched by the air gun collides against CFRP laminates to generate impact damages, and the 3-point fatigue bending test is carried out by using the impacted laminates to investigate the influence of hygrothermals on the effect on the residual bending fatigue strength of CFRP laminates.

• 한국토양비료학회지
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• 제16권3호
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• pp.223-227
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• 1983

볏짚퇴비(堆肥) 제조시(製造時) 염기치환용량(鹽基置渙容量)이 큰 Zeolite를 첨가(添加)하여 퇴적기간중(堆積期間中) 각종양분(各種養分)의 함량(含量) 및 퇴비성상(堆肥性狀)의 변화(變化)를 조사(調査)한 결과(結果)는 다음과 같다. 1. 퇴비(堆肥) 제조시(製造時) Zeolite를 첨가(添加)하여 줌으로써 무첨가(無添加)에 비(比)하여 부숙온도(腐熟溫度)가 현저(顯著)히 높게 유지(維持)되는 경향(傾向)이었다. 2. 퇴적기간중(堆積期間中) $NH_4-N$, $P_2O_5$ 및 $SiO_2$ 함량(含量)은 Zeolite, 계분(鷄糞), 요소등(尿素等)의 첨가(添加)로 증가(增加)되었으며 부숙(腐熟)이 진전(進展)됨에 따라 증가폭(增加幅)이 더 큰 것으로 보아 Zeolite의 양분류실효과(養分流失效果)과 있었던 것으로 사료(思料)된다. 3. 계분(鷄糞), 요소등(尿素等)과 함께 Zeolite를 첨가(添加)하였을 때 퇴적후(堆積後) 30일(日)에 C/N율(率)이 21.7~25.0 이었고, Zeolite 무첨가시(無添加時)는 준적후(准積後) 60일(日)에야 C/N율(率)이 21.3~24.8로써 속성퇴비제조(速成堆肥製造)와 양분(養分)의 유실방지(流失防止)를 위(爲)한 Zeolite의 효과(效果)가 인정(認定)되었다. 4. 퇴적후(堆積後) 90일(日)의 C/N율(率)과 용적감소율(容積減少率)과는 부(負)의 유의상관(有意相關)이 인정(認定)되었다.

• KIEE International Transactions on Electrophysics and Applications
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• 제11C권3호
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• pp.91-95
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• 2001

Reflective holographic polymer dispersed liquid crystal(HPDLC) device has a multilayer structure consisting of alternate layers of polymer and liquid crystal droplets. Periodic modulation of a refractive index reflects light of a specific wavelength in accordance with Braggs law. Samples cured isotropically were illuminated with an Argon-ion lase at 514nm. We optimized the reflcetion efficiency of HPDLC as a function of monomer functionality, LC composition and irradiation intensity. The properties of the HPDLC films were observed by UV-visible spectroscopy. We found that the maximum reflection efficiency depends on the monomer functionality, LC composition, and laser intensity. We expect these films could be used in full-color reflective display by stacking them to obtain a mixture of colors.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2005년도 춘계학술발표대회 논문집
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• pp.141-145
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• 2005

Since the electromagnetic properties of fiber reinforced polymeric laminate composite can be tailored effectively by adjusting its composition and regulating the stacking sequence, it is plausible material for fabricating the radar absorbing structures (RAS) of desired performance. In order to design the effective electromagnetic wave (EM) absorber with the fiber reinforced polymeric laminate composite, its electromagnetic characteristics should be available and could be regulated easily in the target frequency bands. In this study, dielectric characteristics of the E-glass/epoxy laminate composites were measured by the free space method in the X-band frequency range ($8.2\;{\sim}\;12.4\;GHz$). In order to describe the dielectric behavior of laminate composites of arbitrary stacking sequences, the equivalent circuit model and the laminating equations for estimating dielectric properties were proposed, and experimentally verified. From the comparison of the predicted and measured data, the proposed method predicted well the experimentally measured data.

• 한국세라믹학회지
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• 제44권7호
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• pp.349-353
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• 2007

2D SiC fiber-SiC (SiC/SiC) composites were fabricated via slurry infiltration and a stacking process. The effects of the additive composition and content in SiC slurries and the effect of the sintering time on the sintered density and strength of SiC/SiC composites were investigated. A slurry containing $Al_2O_3-Y_2O_3-MgO$ (AYM) additives led to a higher strength compared to a slurry containing $Al_2O_3-Y_2O_3-CaO$ (AYC) additives. The sintered density increased as the sintering time increased and showed a maximum (>98%) at 4 h. In contrast, the flexural strength increased as the sintering time increased and showed a maximum (615 MPa) at 6 h. The relative density and flexural strength increased as the additive content increased.