• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2000년도 춘계학술발표대회 논문집
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• pp.109-115
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• 2000

In the present study, (10%$Al_2O_3$+5%Si)/AZ91 Mg hybrid composite was fabricated using the squeeze casting method. During squeeze casting, molten Mg was infiltrated into the preform of 10%$Al_2O_3$+5%Si and reaction product of $Mg_2Si$ intermetallic compound was formed by the reaction between molten Mg and Si powder. Microstructure has been observed and mechanical properties were evaluated for the reaction squeeze cast (RSC) hybrid composite. It was found that Si powder totally reacted with molten Mg to form $Mg_2Si$. Reinforcement ($Al_2O_3$) and the reaction product ($Mg_2Si$) are fairly uniformly distributed in Mg matrix for the squeeze cast hybrid composite. Mechanical properties were improved with hybridization of reinforcements, namely higher hardness and enhanced wear resistance comparing squeeze cast (15%$Al_2O_3$)/AZ91 Mg composite.

• 한국주조공학회지
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• 제20권1호
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• pp.13-20
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• 2000

In the present study,($10%Al_2O_3+5%Si$)/AZ91 Mg hybrid composite was fabricated using the squeeze casting method. During squeeze casting, Molten Mg was infiltrated into the preform of $10%Al_2O_3+5%Si$ and reaction product of $Mg_2Si$ intermetallic compound was formed by the reaction between molten Mg and Si Powder. Microstructure has been observed and mechanical properties were evaluated for the reaction squeeze cast(RSC) hybrid composite. It was found that Si powder totally reacted with molten Mg to form $Mg_2Si$. Reinforcement($Al_2O_3$) and the reaction product ($Mg_2Si$) are fairly uniformly distributed in Mg Matrix for the squeeze cast hybrid composite. Mechanical Properties were improved with hybridization of reinforcements, namely higher hardness and enhanced wear resistance comparing squeeze cast($15%Al_2O_3$)/AZ91 Mg composite.

• 한국분말재료학회지
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• 제18권1호
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• pp.24-28
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• 2011

Effect of Cu content on microstructural and magnetic properties of a $(Nd_{26.06},Dy_{6.51})Fe_{bal.}$ $Cu_xB_{0.97}$(wt.%), (x = 0.2, 0.3, 0.4, 0.5) strip-cast was studied. The average inter-lamellar spacing in the free surface and wheel side of the strip cast increased as the Cu content increases. The grain uniformity, the grain alignment, and (00L) texture of the strip cast increased with Cu contents up to 0.4 wt.%. These microstructural changes were attributed to the decrease of the effective cooling rate of the melted alloy caused by the decrease of the melting temperature of resulting from Cu addition. Coercivity and remanence were increased because of the grain alignment and (00L) texture improvement with Cu contents up to 0.4 wt.%.

• 한국지진공학회논문집
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• 제25권5호
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• pp.213-221
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• 2021

Many Korean domestic masonry structures constructed since 1970 have been found to be vulnerable to earthquakes because they lack efficient lateral force resistance. Many studies have shown that the brick and mortar suddenly experience brittle fracture and out-of-plane collapse when they reach the inelastic range. This study evaluated the seismic retrofitting of non-reinforced masonry with Hybrid Super Coating (HSC) and Cast, manufactured using glass fiber. Four types of specimen original specimen (BR-OR), one layered HSC (BR-HS-O), two-layered HSC (BR-HS-B), one layered HSC, and Cast (BR-CT-HS-O) were constructed and analyzed using compression, flexural tensile, diagonal compression, and triplet tests. The specimen responses were presented and discussed in load-displacement curves, maximum strength, and crack propagation. The compressive strength of the retrofit specimens slightly increased, while the flexural tensile strength of the retrofit specimens increased significantly. In addition, the HSC and Cast also produced a considerable increase in the ductile response of specimens before failure. Diagonal compression test results showed that HSC delayed brittle cracks between the mortar and bricks and resulted in larger displacement before failure than the original brick. The triplet test results confirmed that the bonding strength of the retrofit specimens also increased. The application of HSC and Cast was found to restrain the occurrence of brittle failure effectively and delayed the collapse of masonry wall structures.

• 한국산학기술학회논문지
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• 제16권3호
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• pp.2279-2286
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• 2015

GFRP 판을 영구 거푸집 및 주요 인장 보강재로 활용한 GFRP-콘크리트 하이브리드 구조의 활용에 대해 최근 활발하게 연구가 이루어지고 있다. GFRP 판과 콘크리트 하이브리드 구조의 거동을 이해하기 위해서는 GFRP 판과 현장타설 고강도콘크리트 사이의 정량적인 국부 부착슬립모델이 필요하다. 본 연구에서는 이러한 하이브리드 구조에 간단하게 적용할 수 있는 2중 직선 단순 부착슬립관계를 제안하고자 한다. 본 연구에서 제안된 단순 부착슬립관계의 최대 평균 부착응력은 3.29MPa이며, 초기 기울기는 35.66MPa/mm, 총 슬립은 0.23mm이고 계면 파괴에너지는 0.37kN/m로 나타났다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권3호
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• pp.1035-1056
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• 2015

The efficiency of live Peer-to-Peer (P2P) streaming protocols depends on the appropriateness and the management abilities of their underlying overlay multicast. While a tree overlay structure confines transmission delays efficiently by maintaining deterministic delivery paths, an overlay mesh structure provides adequate resiliency to peers dynamics and easy maintenance. On the other hand, content freshness, playback fluidity and streaming continuity are still challenging issues that require viable solutions. In this paper, we propose a Hybrid Live P2P Streaming Protocol (HLPSP) based on a hybrid overlay multicast that integrates the efficiency of both the tree and mesh structures. Extensive simulations using OMNET++ are conducted to investigate the efficiency of HLPSP in terms of relevant performance metrics, and position HLPSP with respect to DenaCast the enhanced version of the well-known CoolStreaming protocol. Simulation results show that HLPSP outperforms DenaCast in terms of startup delay, end-to-end delay, play-back delay and data loss.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 봄 학술발표회논문집(II)
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• pp.487-492
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• 1998

The purpose of this study is to investigate the external joints flexural of hybrid system(RPC) which is consist of precast concrete slabs and cast in site concrete walls. The external joint's specimens were prepared by types of joint detail and were tested under cyclic load which used yielding displacement. The results of external joints of hybrid system showed that the strength capacity of RPC is little different than RC and that the energy dissipation capacity of RPC is similar to RC.

• Restorative Dentistry and Endodontics
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• 제26권1호
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• pp.51-63
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• 2001

In order to know the effect of dentin bonding agents on the restoration of cervical abrasion, Scotchbond Multipurpose Single Bond and Clearfil Liner Bond 2 were used in 51 teeth with abrasion lesion and normal teeth. The surface structure and dentinal tubules of acid etched dentin and resin replica were examined using scanning electron microscopy. The interfacial morphology between dentin and adhesives was investigated by confocal laser scanning microscopy. Following results were obtained. 1. The hybrid layer and resin tag of the dentin showing cross-sectional surface of dentinal tubules are thicker and longer than those of dentin showing oblique surface of dentinal tubules. 2. The sclerotic cast was frequently observed in dentinal tubule, and the cast looked like cuboidal or rhomboidal-shaped crystals clumped from outer side to inner side. 3. The formation of hybrid layer and resin tag was the most prominent in Scotchbond Multipurpose group, whereas Clearfil Liner Bond 2 group showed very poor formation. The formation of hybrid layer and resin tag in Single Bond group was less than Scotchbond Multipurpose group.

• Advances in concrete construction
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• 제8권1호
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• pp.9-19
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• 2019

This paper describes an experimental investigation on hybrid fiber reinforced concrete (HYFRC) beams. And the main aim of this present paper is to examine the dynamic characteristics and damage evaluation of undamaged and damaged HYFRC beams under free-free constraints. In this experimental work, totally four RC beams were cast and analyzed in order to evaluate the dynamic behavior as well as static load behavior of HYFRCs. Hybrid fiber reinforced concrete beams have been cast by incorporating two different fibers such as steel and polypropylene (PP). Damage of HYFRC beams was obtained by cracking of concrete for one of the beams in each set under four-point bending tests with different percentage variation of damage levels as 50%, 70% and 90% of maximum ultimate load. And the main dynamic characteristics such as damping, fundamental natural frequencies, mode shapes and frequency response function at each and every damage level has been assessed by means of non-destructive technique (NDT) with hammer excitation. The fundamental natural frequency and damping values obtained through dynamic tests for HYFRC beams were compared with control (reference) RC beam at each level of damage which has been acquired through static tests. The static experimental test results emphasize that the HYFRC beam has attained higher ultimate load as compared with control reinforced concrete beam.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.1115-1118
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• 2006

Using a thermally-crosslinkable organosiloxane-based organic-inorganic hybrid material, solution processable gate dielectric layer for organic thin-film transistors (OTFTs) have been fabricated. The hybrid dielectrics are synthesized by the sol-gel process, followed by the heat-treatment at $190{\bullet}\;.{\bullet}$ To investigate the electrical property of hybrid dielectric, leakage current behavior and capacitance were measured. To fabricate coplanar-type OTFTs, Au/Cr electrode was deposited onto the heavily doped silicon substrate with the organic-inorganic hybrid dielectric layer and then ${\alpha},{\omega}-dihexylquaterthiophene$ was drop-cast between source and drain electrical performance of the fabricated transistor.