• 임산에너지
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• 제20권1호
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• pp.62-72
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• 2001

목재의 알칼리 팽윤특성을ㄹ 해명하기 위해 국내산 주요 침·활엽수 4수종의 주요 구성요소의 알칼리 팽윤 거동을 횡단면 절편을 이용하여 조사하였다. 그 결과, 일본잎갈나무의 가도관 직경은 잣나무보다 크게 팽윤하였으며, 가도관의 벽두께는 10% 이상의 알칼리 수용액에 처리시 높은 팽윤율을 나타냈다. 알칼리 처리에 의해 도관의 직경은 방사방향으로 수축하였고, 접선방향으로 다소 팽윤하였다. 목섬유의 세코벽두께는 5%의 알칼리처리에서도 수분팽윤에 비해 3배 이상의 높은 팽윤성을 나타앴고, 알칼리 처리후 일본잎갈나무의 가도관 직경, 목섬유 직경 및 세포벽두께는 거의 등방적인 수축현상을 보여주었다. 또한 미처리 시료에 비해 머서화 처리 구성요소의 세포직경은 수축되었고, 세포벽은 팽윤되었다. 알칼리처리 과정에서 셀룰로오스 결정형의 변화는 없었지만 상대결정화도와 미결정의 폭이 다소 증가되었다. 결론적으로 알칼리의 농도, 수종, 세포의 종류가 목재의 알칼리 팽윤 특성에 크게 관여하는 것으로 생각되었다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1859-1864
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• 2004

An effective methodology is reported for the optimal design of multisite batch production/transportation and storage networks under uncertain demand forecasting. We assume that any given storage unit can store one material type which can be purchased from suppliers, internally produced, internally consumed, transported to or from other plant sites and/or sold to customers. We further assume that a storage unit is connected to all processing and transportation stages that consume/produce or move the material to which that storage unit is dedicated. Each processing stage transforms a set of feedstock materials or intermediates into a set of products with constant conversion factors. A batch transportation process can transfer one material or multiple materials at once between plant sites. The objective for optimization is to minimize the probability averaged total cost composed of raw material procurement, processing setup, transportation setup and inventory holding costs as well as the capital costs of processing stages and storage units. A novel production and inventory analysis formulation, the PSW(Periodic Square Wave) model, provides useful expressions for the upper/lower bounds and average level of the storage inventory. The expressions for the Kuhn-Tucker conditions of the optimization problem can be reduced to two sub-problems. The first yields analytical solutions for determining lot sizes while the second is a separable concave minimization network flow subproblem whose solution yields the average material flow rates through the networks for the given demand forecast scenario. The result of this study will contribute to the optimal design and operation of large-scale supply chain system.

• 한국전기전자재료학회논문지
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• 제30권6호
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• pp.349-355
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• 2017

Zinc sulphide (ZnS) nanoparticles were fabricated by hydrothermal synthesis at $180^{\circ}C$ for 12 h. Two kinds of ZnS powder (hydrothermal synthesized ZnS and commercial ZnS) were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM) for phase and microstructure, respectively. The XRD patterns showed that all ZnS nanoparticles have a sphalerite (cubic) structure. The nanoparticles of two different ZnS powders were sintered by spark plasma sintering. The sintered ZnS were analyzed by XRD, SEM, and FT-IR. We found that the transmittance of the infrared region is highly dependent on the density and crystal structure of sintered ZnS and the purity of the starting ZnS powder.

• 한국축산식품학회지
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• 제30권1호
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• pp.20-27
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• 2010

Deer velvet antler was subjected to the extraction process using boiling water at three different temperatures (100, 110 and $120^{\circ}C$) and 70% ethanol solution. Functional components such as uronic acid, sulfated-glycosaminoglycans (sulfated-GAGs) and sialic acid in the extracts were analyzed, and their antioxidant activities were investigated using several in vitro models. Uronic acid and sulfated-GAGs content of each extract significantly decreased with increasing extraction temperature (p<0.05), while the residues obtained from the upper and middle part of the antler had a higher uronic acid content than the residues obtained from the base section. Sialic acid contents were highest in compounds extracted at $110^{\circ}C$, followed by 120 and $100^{\circ}C$. The 70% ethanol extracts also had a high levels of uronic acid content, but not for sulfated-GAGs and sialic acid. All extracts showed good antioxidant ability in a dose-dependant manner, with the $100^{\circ}C$ residue exhibiting the strongest activity compared to the 110 and $120^{\circ}C$ extracts. In relation to the hydroxyl radical scavenging activity and reduction power, the 70% ethanol extract exhibited the strongest activity. Furthermore, the velvet antler extracts inhibited apoptosis in hydrogen peroxide-induced PC-12 cells.

• 한국디지털건축인테리어학회논문집
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• 제5권1호
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• pp.9-16
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• 2005

In Interior design, light is the most important factor in deciding color, texture and illumination level which are the basic factors of spatial design. To apply rendering technologies on prediction of illuminating effect, it is important to understand and analyse the basic properties of the illumination models that are local illumination model and global illumination model. The illumination models in computer graphics express the factors which determine the surface color, texture and light distribution through the reflection. The purpose of this study is to propose the best way of shading algorithm in interior space provided by the computer, based on the experimental analysis that 5 shading methods are applied to the interior space. The results of this study were as followed. 1) Local illumination models that are Lambert shading, Ground shading and Phong shading are not suitable to the prediction of interior illumination effect. 2) Ray tracing that is global illumination model could be adopted to interior illumination effects. Ray tracing is a very versatile algorithm because of the large range of lighting effects it can model. 3) Neither radiality nor ray tracing offers a complete solution for simulating all interior illumination effects. 4) Radiosity excels at rendering diffuse-to-diffuse inter-reflections and ray tracing excels at rendering specular reflections. By merging both shading techniques, that offers the best of both. Using computer technologies to simulate lighting in preliminary design stage which will provide information for designers and occupants to determine the effect of using artificial light sources at each stage of their design process. Further study in illumination analysis, prediction of illumination effect, and lighting calculation is required as computer media expands.

• 가정과삶의질연구
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• 제10권1호통권19호
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• pp.139-156
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• 1992

The purpose of this study is to provide basic data for the solution of occupant problems related to the house purchasing. For the purpose, the content of problems and actual conditions of house purchasing are examined. Also the structural analysis of occupant's evaluation of housing purchasing is executed. For these purposes, a survey was conducted using questionnaires. Data analysis was conducted from 263 house owners in Seoul. Major findings of this study can be summarized as follows ; 1) The frequency and the contend of occupation's problems with house purchasing are studied. The rate of housing problem occurrence is 71.2%, so the majority of respondents experience problems. The most common problems are the difference from supplier's description(53.2%). The rate of housing problems occurrence is qenerally high with the houses of mult-housedhold houses and mult-family houses type. 2) There is a significant difference in housing satisfaction extend according to the existence of an housing problem experience. Therefore, it can be inferred that experience of housing problem has an important effects upon the housing satasfaction extent. 3) Occupants' countermoves to the housing problems are examined. Occupants make active regotiation with house suppliers only on the direct damages such as an economical loss or a living difficulty. However, they usually make no countermove at all on the other indirect troubles. House suppliers make correction only when occupants' countermove actively, but refuse to do when occupant's reactions are not active. 4) As a means of countermove, most occupants depend on direct personal regotiation with house suppliers. The rate of using a specialist or public and private consultant is extremely low. 5) Problems with house purchasing and the countermove process of both occupant and house supplier are displayed in the figure(Fig. 4-4).

• 한국염색가공학회지
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• 제32권2호
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• pp.111-120
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• 2020

In this study, lignin/chlorinated poly(vinyl chloride)(CPVC) blended fibers have been produced for the development of low-cost carbon fiber. Carbon fiber manufacturing was accomplished through stabilization and carbonization process. The lignin/CPVC blended fibers were prepared by wet spinning method. Dimethylacetamid e(DMAc) and cychlohexanone in a ratio of 5:1(wt%) was employed as co-solvent. The ratio of lignin/CPVC was prepared at 0/10, 1/9, 2/8, 3/7, 4/6, and 5/5(wt%). The spinning solution was extruded at a rate of 0.1 to 0.4ml/min according to the blending ratio. The speed of the rollers was the same for all ratios(draw ratio=1). Analysis of fiber cross-section by scanning eletron microscopy(SEM) showed that as the lignin ratio increased in the same coagulation bath and distilled water, the pore size of the spinning fiber decreased. Therefore, the highest tensile strength of the blending fibers was 6.3±1.2MPa at the 5/5 ratio. The carbon fiber also showed the best tensile strength of 120.78±2.43MPa at 5/5 ratio.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2014년도 하계학술대회
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• pp.157-159
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• 2014

In this paper, we introduce SlimSRP, an ultra-low-power digital signal processor (DSP) solution for mobile audio and voice applications. So far, application processors (APs) have taken charge of all the tasks in mobile devices. However, they have suffered from short battery life problems to deal with complex usage scenarios, such as always-on voice trigger with continuous audio playback. From extensive analysis of audio and voice application characteristics, SlimSRP is designed to relive the performance and power burden of APs. It employs three-issue VLIW architecture, and the major low-power and high-performance techniques include: (1) an optimized register-file architecture friendly for constants generation, (2) a powerful instruction set to reduce the number of register file accesses and (3) a unique instruction compression scheme that contributes to saved memory size and reduced cache miss. An implementation of SlimSRP runs at up to 200MHz and the logic occupies 95K NAND2 gates in Samsung 28LPP process. The experimental results demonstrate that a MP3 decoder application with a 128kbps 44.1kHz input can run at 5.1MHz and the logic consumes only 22uW/MHz.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2010년도 추계학술발표논문집 1부
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• pp.110-114
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• 2010

Li-incorporated mesoporous $TiO_2$ materials with various pore-sized istributions were synthesized by using triblockcopolymers via a sol-gel process in a queous solution. The properties of the se materials were characterized by HR-TEM, XRD, and BET analysis. All particles have spherical morphology with a diameterrange of $1-3{\mu}m$. The mesoporous $TiO_2$ materials calcined at $400^{\circ}C$ and their specific surface area, average pore size and crystallite sizes were 210 $m^2g^{-1}$, 6.4 nm and 8.8 nm respectively. The Li-incorporated mesoporous $TiO_2$ were tested for $CO_2$ adsorption and its adsorption capacity is 90mg/g. The Li-incorporated mesoporous $TiO_2$ ar eobserved to be thermally stable, recyclable and greens or bent for $CO_2$ capture. The effect of bimetallic $ZrLiTiO_2$ is also studied for $CO_2$ adsorption.

• Rapid Communication in Photoscience
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• 제3권4호
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• pp.70-72
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• 2014

Visible-light irradiation of MeCN solution containing di(hydroxo)metallo(tetraphenyl)porphyrin complex $(tppM(OH)_2$: 1a; $M=Sb(V)^+Br^-$, 1b; $M=P(V)^+Cl^-$, 1c; M=Ge(IV)) and 2-mercaptoethanol (2-ME) as a substrate under aerated condition gave bis(2-hydroxyethyl)disulfide (2-HEDS) as an oxidative product of 2-ME. It is indicated that the oxidation of 2-ME should proceed with a photocatalytic process by 1, because the turn over number (TON) for the formation of 2-HEDS was over unit. The TON was determined to be 642 as a maximum value when 1a was used as a sensitizer. The formation of 2-HDES was extremely slow under argon atmosphere. The fluorescence of 1 was not quenched by 2-ME at all, and the free energy change (${\Delta}G$) with electron transfer (ET) from 2-ME to excited triplet state of $1(^31^*)$ was estimated as a negative value. The quenching rate constant ($k_r$) of $^31^*$ by 2-ME, obtained by the kinetics for the formation of 2-HEDS, strongly depends on ${\Delta}G$. These findings indicate that 1-sensitized oxidation was initiated by photoinduced ET from 2-ME to $^31^*$ to generate both radical cation of 2-ME ($2-ME^{+\bulle}$) and porphyrin radical anion ($1^{-\bulle}$), resulting that the formation of 2-HEDS can be proceeded by the dimerization of $2-ME^{+\bulle}$, and through a catalytic cycle due to returning to 1 by the ET from $1^{-\bulle}$ to molecular oxygen.