• Journal of the Korean Chemical Society
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• v.62 no.4
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• pp.269-274
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• 2018

Surface renewable nano-$RuO_2$/poly(methyl methacrylate) polymeric composite pH electrodes were prepared. The composite electrode with 53 wt% of nano-$RuO_2$ showed similar good response characteristics to nano-$IrO_2$ composite electrode reported earlier. It showed response slope of -58.7 mV/pH, response time of <1 s, surface renewability of $-57.0{\pm}0.3mV/pH$ (n=5) and long time stability for a month as well as low interferences but high interferences by electrochemically active species like $I^-$ and $Fe(CN){_6}^{3-}$. However, the response slope and time became worse at higher pH than 9 compared to those of nano-$IrO_2$ composite electrodes possibly due to the difference of physical properties resulting from higher content of nano-$RuO_2$ in polymeric composite matrix.

• Journal of the Korea Society for Simulation
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• v.15 no.1
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• pp.69-75
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• 2006

P2P services occupy more then 50% of the internet traffics. A huge number of query packets are generated since pure P2P based models rely on message flooding for their query mechanisms. In this study, the numbers of query messages generated in the pure P2P and hybrid P2P model are analyzed. The results show that hybrid P2P models also could suffer from message flooding. To reduce the message flooding, this study proposes an interest based clustering mechanism for hybrid P2P services. By applying this clustering algorithm, it could reduce 99.998% of the message flooding. The proposed algorithm also reduces the cost of the joining operations by storing previous supernodes.

• Journal of Digital Convergence
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• v.13 no.5
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• pp.245-250
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• 2015

The P2P technology is becoming a technology for receiving a service, such as the latest YouTube and Facebook. P2P technology can be easily downloaded to a large amount of multimedia content over a distributed environment. However, pictures, music, a large amount of multimedia content such as videos each user is unable to manage the content management operating smoothly because, Song communication processing overhead caused when the reception is likely to remain the problem. In this paper, we propose a convergence content management technique that provides a low communication overhead of the frequency of use of the convergence content when trying to provide a large amount of convergence content to users in a distributed environment. Our method can be used to select the appropriate frequency is high among the shared content on the P2P multimedia environments that are distributed across a frequency of use of the convergence content and provides the service. Experimental evaluation proposed method, the convergence content browsing speed than conventional techniques improved communication about 13.3% and reduced overhead to about 9.5%.

• Koreanishche Zeitschrift fur Deutsche Sprachwissenschaft
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• v.6
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• pp.1-21
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• 2002

'임시복합명사'는 명사 하나 하나의 의미가 개인의 머릿속에 저장되어 있지만, 이들이 결합해서 생긴 단어가 일반적인 언어사전에 등록되어 있지 않고 문맥에 따라 새로운 의미가 형성되어서 결합된 명사를 의미한다. 따라서 이 논문에서는 사전의 목록에 등록되어 있지 않아서 의미적으로 애매한 복합명사들을 '임시복합명사' ad-hoc Nominal-komposita 라고 지칭하였다. 이때 이러한 '임시복합명사'를 생성하는데 있어서 '임시복합명사'를 구성하는 각 요소들은 새로운 복합명사를 만드는데 필요한 '입력'의 역할을 담당한다. 이 논문에서는 '임시복합명사'를 구성하는데 필요한 일종의 다양한 원칙들을 다루어 보았다. 그러한 원칙들은 순수 언어학적인 논거를 바탕으로 '임시복합명사'를 생산하고 해석해 나가는 과정에 대한 타당성을 입증해 주었다. 그러나 일반적인 지식 Weltwissen과 텍스트 문맥에 맞는 구조를 편입함으로써 그 형태와 해석이 가능한 다른 형태의 복합어는 이 논문에서 자세히 다루지 않았다. 이 논문에서 제시된 복합명사의 생성과 해석과정은 대부분의 경우 복합어 고유의 현상만을 설명한 것이 아니라, 일반적으로 복합어를 생산하고 해석하는 과정을 다룬 것이다. 마찬가지로 이 점은 텍스트 문맥과 상관없이 해석이 가능한 복합어 내지는 텍스트 문맥에 따라 해석이 가능한 복합어에서도 똑같이 적용된다. 텍스트의 문맥을 통해서 자체적으로 해석이 가능하지 않은 복합어를 명확하게 의미를 부여하고 해석하는 과정, 예를 들어 의사소통상에서 일반적인 지식을 이용하여 '임시복합어'를 해석하는 과정은 이후의 연구에 다양하게 다루어 질 테마가 될 것임이 분명하다. 또한 '임시복합명사'를 생산하기 위해 이 논문에서 다룬 전제조건들은 또 다른 새로운 복합어를 생산하는데, 예를 들어 명사로부터 파생된 동사들의 복합어를 연구하는데 밑거름이 될 것이다.학의 강력한 연구가 요구된다.에 기대어 텍스트, 문장, 어휘영역 등이 투입되어 적용되었으며, 이에 상응되게 구체적인 몇몇 방안들이 제시되었다. 학습자들이 텍스트를 읽고 중심내용을 찾아내며, 단락을 구획하고 또한 체계를 파악하는데 있어서 어휘연습은 외국어 교수법 측면에서도 매우 관여적이며 시의적절한 과제라 생각된다. Sd 2) PL - Sn - pS: (1) PL[VPL - Sa] - Sn - pS (2) PL[VPL - pS] - Sn - pS (3) PL(VPL - Sa - pS) - Sn - pS 3) PL[VPL - pS) - Sn -Sa $\cdot$ 3가 동사 관용구: (1) PL[VPL - pS] - Sn - Sd - Sa (2) PL[VPL - pS] - Sn - Sa - pS (3) PL[VPL - Sa] - Sn - Sd - pS 이러한 분류가 보여주듯이, 독일어에는 1가, 2가, 3가의 관용구가 있으며, 구조 외적으로 동일한 통사적 결합가를 갖는다 하더라도 구조 내적 성분구조가 다르다는 것을 알 수 있다. 우리는 이 글이 외국어로서의 독일어를 배우는 이들에게 독일어의 관용구를 보다 올바르게 이해할 수 있는 방법론적인 토대를 제공함은 물론, (관용어) 사전에서 외국인 학습자를 고려하여 관용구를 알기 쉽게 기술하는 데 도움을 줄 수 있기를 바란다.되기 시작하면서 남황해 분지는 구조역전의 현상이 일어났으며, 동시에 발해 분지는 인리형 분지로 발달하게 되었다. 따라서, 올리고세 동안 발해 분지에서는 퇴적작용이, 남황해 분지에서는 심한 구조역전에 의한 분지변형이 동시에 일어났다 올리고세 이후 현재까지, 남황해 분지와 발해 분지들은 간헐적인 해침과 함께 광역적 침강을 유지하면서 안정된 대륙 및 대륙붕 지역으로 전이되었다.

• Composites Research
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• v.13 no.6
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• pp.1-8
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• 2000

The fabrication Process of $Al_2O_{3p}$/AC8A composites by pressureless infiltration technique and the effects of additive Mg content and volume fraction of particulate reinforcement on mechanical and wear properties were investigated. It was found that the bending strength decreased with increasing volume fraction of $Al_2O_{3p}$ particles. Whereas hardness increased with volume fraction of $Al_2O_{3p}$ particles. The decrement of strength in case of high volume fraction of $Al_2O_{3p}$ particles was attributed to high porosity level. In terms of additive Mg content, $Al_2O_{3p}$/AC8A composites containing around 5~7wt% of additive Mg indicated the highest strength, and hardness values increased with additive Mg contents. Wear resistance of AC8A alloy were improved by reinforcement of $Al_2O_{3p}$ particles especially at high sliding velocity. Wear property of $Al_2O_{3p}$/AC8A composites and AC8A alloy exhibited different aspects. $Al_2O_{3p}$/AC8A composites indicated more wear loss than AC8A alloy at slow velocity region. However a transition point of wear loss was found at middle velocity region which shows the minimum wear loss and wear loss at high velocity region exhibited almost same value as at slow velocity region, whereas wear loss of AC8A alloy almost linearly increased with sliding velocity. It was found that $Al_2O_{3p}$/AC8A composites containing $Al_2O_{3p}$ volume fraction of 20% exhibited abrasive wear surface regardless of sliding velocity and $Al_2O_{3p}$/AC8A composites containing $Al_2O_{3p}$ volume fraction of 40% showed slightly adhesive wear surface at low sliding velocity, and it progressed to severe wear as increasing the sliding velocity.

• Restorative Dentistry and Endodontics
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• v.35 no.1
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• pp.51-58
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• 2010

Dental composites have improved significantly in physical properties over the past few decades. However, polymerization shrinkage and stress is still the major drawback of composites, limiting its use to selected cases. Much effort has been made to make low shrinking composites to overcome this issue and silorane-based composites have recently been introduced into the market. The aim of this study was to measure the volumetric polymerization shrinkage kinetics of a silorane-based composite and compare it with conventional methacrylate-based composites in order to evaluate its effectiveness in reducing polymerization shrinkage. Five commercial methacrylate-based (Beautifil, Z100, Z250, Z350 and Gradia X) and a silorane-based (P90) composites were investigated. The volumetric change of the composites during light polymerization was detected continuously as buoyancy change in distilled water by means of Archemedes' principle, using a newly made volume shrinkage measurement instrument. The null hypothesis was that there were no differences in polymerization shrinkage, peak polymerization shrinkage rate and peak shrinkage time between the silorane-based composite and methacrylate-based composites. The results were as follows: 1. The shrinkage of silorane-based (P90) composites was the lowest (1.48%), and that of Beautifil composite was the highest (2.80%). There were also significant differences between brands among the methacrylate-based composites. 2. Peak polymerization shrinkage rate was the lowest in P90 (0.13%/s) and the highest in Z100 (0.34%/s). 3. The time to reach peak shrinkage rate of the silorane-based composite (P90) was longer (6.7 s) than those of the methacrylate-based composites (2.4-3.1 s). 4. Peak shrinkage rate showed a strong positive correlation with the product of polymerization shrinkage and the inverse of peak shrinkage time (R = 0.95).

• Journal of Sericultural and Entomological Science
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• v.36 no.2
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• pp.147-151
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• 1994

This study was carried out investigate the characteristics of Habutae and Chiffon woven with silk and polyester(S/P) compound yarn. The S/P compound yarn could be produced by the automatic reeling machine with attachment of air jetting device, polyester yarn guider and tension control apparatus. The surface structure, tensile property and dyeing fastness of S/P compound fabric were examined for the fabric properties. Electron microscopy revealed that most part of S/P compound yarn was well interlaced and some silk part of compound yarn were hidden by polyester on an examination of surface of chiffon fabric. By the one bath and two step dyeing of disperse and acidic dyes, the colour fastness of S/P compound fabrics were 4 grade above. The tenacity and initial modulus of the finished S/P compound fabric were lower than those of grey and degummed fabrics, but reversed in elongation.

• Applied Microscopy
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• v.29 no.3
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• pp.281-289
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• 1999

The stirred and thixoformed $SiC_p/AZ91HP$ Mg composites are studied on the basis of microstructural analysis using transmission electron microscopy (TEM). The products of interfacial reaction are identified as $Mg_2Si$, MgO and $Mg_{17}Al_{12}$ phases and the crystallized phases are found to be orthorhmbic $Al_6Mn$ and decagonal T phases. It is shown that $Mg_2Si$ and $Mg_{17}Al_{12}$ phases are found at the surface of $SiC_p$ and $Al_6Mn$ is found near interface and crystallized on the matrix. Phase identification is carried out by crystallographic work based on primitive cell volume, zero order Laue zone (ZOLZ) patterns and single convergent beam electron diffraction (CBED) patterns containing higher order Laue zone ring from a nanosized region.

• Composites Research
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• v.12 no.3
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• pp.36-44
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• 1999

The fabrication process of $Al_2O_{3p}/Al$ composite by in-situ process was investigated. The effects of processing variables such as addition type and content of Mg, processing temperature and time on the infiltration behavior of molten Al, microstructure and hardness were investigated. When the pure Al was infiltrated into mixtures of Mg and $Al_2O_3l$ powder, processing temperature required to spontaneous infiltration was decreased, and the content of Mg was the most powerful variable for infiltration of molten Al. But when the Al-Mg alloy was infiltrated into $Al_2O_3l$ particles, infiltration ratio indicated nearly same value regardless of Mg content in alloy and processing temperature, and critical processing temperature required to spontaneous infiltration was $800^{\circ}C$. The $Al_2O_{3p}/Al$ composites which were fabricated by mixtures of Mg and $Al_2O_3l$ powders resulted in high hardness value, but hardness values were scattered due to non uniform dispersion of $Al_2O_3l$ particles by excessive reaction of Mg.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.3
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• pp.423-429
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• 2002

Recently, the clinical uses of flowable composite resins have increased because of fast, convenient and excellent accessibility, but little has been reported about physical properties of flowable resins. The purpose of this study was to measure and compare the physical properties(compressive strength, relative flowability, relative radiopacity) of 4 contemporary flowable composite resins(Filtek flow, Tetric Flow, Revolution Palfique Estelite LV high flow). The results were as follows; 1. There were no significant differences between 4 flowable composite resins in compressive strength, but all were lower than that of traditional hybrid composite resin(p<0.001). 2. The relative flowability were increased in order of Palfique Estelite LV high flow, Revolution, Filtek flow, Tetric Flow and sealant(p<0.001), but there were no significant differences between Filtek flow and Tetric Flow. 3. There were significant differences between flowable composite resins in relative radiopacity and they showed similar or higher radiopacity than dentin(p<0.001), especially Tetric Flow and Filtek Flow showed higher radiopacity than enamel(p<0.001). This results suggested that the stress of application area have to be considered since flowable composite resins have lower compressive strength than hybrid composite, and the differences of flowability between these flowable composite resins can be considered when they are selected. All tested flowable composite resins showed optimal radiopacity to ISO's recommend.