• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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• pp.350-358
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• 2009

To enhance the application of the reinforced retaining walls in the railway industry, this paper suggested a type of reinforcement subgrade with short reinforcement and rigid facing. To become popular the reinforced retaining walls in the industry, the deformation of retaining walls should be controlled below some limited level. In this paper, small scale and full scale tests of the proposed retaining walls were performed and their deformation characteristics were evaluated. Even though it has short reinforcement, the rigid type retaining wall had small deformation to the external train loading than the segmental type retaining wall had.

• 펄프종이기술
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• 제37권5호통권113호
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• pp.25-34
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• 2005

The chemical composition of the differentiating xylem of Populus deltoides M. was investigated and compared with that of sapwood. The cell wall polysaccharides were extracted sequentially from adifferentiating xylem and fractionated with gel chromatography. The sugar composition of each fraction was analyzed with G..C and H.P.L.C. The cell wall of the differentiating xylem is rich with the pectin substance and hemicellulose compared with that of sapwood. The water-extracted polysaccharides from the differentiating xylem were composed mainly of xylose and glucose residues. The sugar composition of some of the fractions in the gel filtration of purified $H_{2}O$ polysaccharide suggest that xyloglucan was extracted with $H_{2}O$ from differentiating xylem. Also, we can supposed that the purified $H_{2}O$ polysaccharide might be xyloglucan from the spectrometric data(IR and NMR) of purified $H_{2}O$ polysaccharide.

• 펄프종이기술
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• 제32권5호
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• pp.8-13
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• 2000

X-ray diffraction technique was used to quantify change of cellulose crystallinity during refining. XRD data confirmed that fiber wall delamination was caused by the structural conversion of celluloses which occurred in a liquid medium during refining. The quantified crystallinity of celluloses in pulp fibers was closely associated with the change of fiber wall delamination, which was defined by measurement of fiber wall thickness. In particular, it was well recognized that low intensity beating showed a better response in the change of crystallinity than high intensity one. The decrease o cellulose crystallinity during refining considerably enhanced the improvement of interfiber bonding ability of a dried sheet.

• 한국농촌건축학회논문집
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• 제15권4호
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• pp.17-24
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• 2013

Rural community in Korea being changed to aging community, declining population and income loss by the industrialization and the urbanization. The weak class in rural is confronted with more poorly environment. So it is needed to check the quality of the weak class's house in rural. Basically proposes of this paper is to find ways about rural housing improving and the vitality of rural community. This paper contents rural housing problems through the paper review and house repair characteristics for the weak class. Data for statics analysis were obtained from house repair support program for the weak class in Jeonnam province from 2011 to 2012. The results of this paper are as follow: First, house repair items ranking for the weak class in rural was insulation & heating, toilet, structure, indoor environment, electricity, outside and kitchen & waterproof. This result was reflected that weak class's energy bills is high ratio compared with income. Second, health facilities were improved for the socially disadvantaged's convenience in considering that most of weak class is a senior. Last, most of houses for weak class in rural are old clay wall and block wall. So these houses are reinforced the wall for structural safety.

• Steel and Composite Structures
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• 제20권4호
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• pp.931-950
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• 2016

Ratcheting deformation of pressurized Z2CND18.12N stainless steel $90^{\circ}$ elbow pipe with local wall thinning subjected to constant internal pressure and reversed bending was studied using finite element analysis. Chen-Jiao-Kim (CJK) kinematic hardening model, which was used to simulate ratcheting behavior of pressurized $90^{\circ}$ elbow pipe with local wall thinning at extrados, flanks and intrados, was implemented into finite element software ANSYS. The local wall thinning was located at extrados, flanks and intrados of $90^{\circ}$ elbow pipe, whose geometry was rectangular cross-section. The effect of depth, axial length and circumferential angle of local wall thinning at extrados, flanks and intrados on the ratcheting behaviors of $90^{\circ}$ elbow pipe were studied in this paper. Three-dimensional elastic-plastic analysis with Chen-Jiao-Kim (CJK) kinematic hardening model was carried out to evaluate structural ratcheting behaviors. The results indicated that ratcheting strain was generated mainly along the hoop direction, while axial ratcheting strain was relatively small.

• 농촌계획
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• 제12권2호
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• pp.27-35
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• 2006

The purpose of this paper is to estimate the economic value of Multi-functionality Roles including landscape and so on, which the stone fences in Jejudo possess, using Dichotomous Choice Contingent Valuation Method(DC-CVM). The stone wall is life cultural heritance of Cheju islanders. It has functions like Development of Favorable Landscapes, Maintenance of Cultural Heritage, and Recreation/Relaxation. Expectation from Cheju visitors shows that the existence and inheritance value of the stone wall is higher then we expected. According to the research that we had done from the people that had agreed to contribute the stone wall, the result was that the public commercial value of Cheju tradition stone will increase every yew(2006: 367 billion won, 2011: 437.1 billion won). Therefore, preserving the stone wall that has Multi-functional Roles and values can lead to huge economic value in the future. But farmhouses in the stone wall conservation area are being supported 6 million won every year. This is only 10% of the income that farmhouse ems per year. Thus, stone wall preservation policy and plan that can raise green-tour commercial value of Cheju Island of long-term inside measurement will have to be propelled continuously.

• 한국전산유체공학회지
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• 제17권2호
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• pp.93-99
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• 2012

The present study focuses on the case of developing flow with in a channel containing a long array of sinusoidal waves (2a/${\lambda}$=0.1, ${\lambda}$=h, ${\lambda}$ is the wavelength, 2a is the wave height, h is the mean channel depth) at the bottom wall. The Reynolds number defined with channel height, h and the mean velocity, U, is Re=6,700. The channel is sufficiently long such that transition is completed and the flow is fully developed over the downstream half of the channel. For the case of an incoming steady flow with no resolved turbulence, the instantaneous flow fields in the transition region are characterized by the formation of arrays of highly-organized large-scale hairpin vortices whose dimensions scale with that of the roughness elements. The paper explains the mechanism for the formation of these arrays of hairpin vortices and shows these eddies play the primary role in the formation of the large-scale streaks of high and low velocity over the wavy wall region. The presence of resolved turbulence in the incoming flow, reduces the streamwise distance needed for the streaks to develop over the wavy region, but does not affect qualitatively the transition process. In the fully-developed region, isolated and trains of large-scale hairpins play an important role in the dynamics of the streaks over the wavy wall.

• 대한토목학회논문집
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• 제31권2C호
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• pp.65-74
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• 2011

본 논문에서는 대구경 소일-시멘트 교반체를 보강재로 적용한 토류벽의 굴착 시 거동을 현장 시험시공 결과를 통해 분석하였다. 먼저 대구경 소일-시멘트 교반체 공법에 대한 설명 및 기본 설계개념을 기술하였다. 공법을 9.8 m 굴착 현장에 적용하면서 굴착 단계별 벽체의 거동을 수평변위 및 하중 계측자료를 바탕으로 분석하였으며, 굴착에 의해 발생한 인접지반의 변위를 침하 계측 및 수치해석을 통해 평가하였다. 분석 결과, 대구경 소일-시멘트 교반체로 보강된 벽체는 보강재 길이가 0.45 H (H:벽체 높이) 이상인 경우 변위 및 토압 발생 거동이 소일 네일링과 같은 기존 공법으로 지지된 토류벽과 유사한 것으로 나타났다.

• Journal of Advanced Marine Engineering and Technology
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• 제34권5호
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• pp.718-724
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• 2010

공동수조와 예인수조에서의 프로펠러 단독특성 차이를 보정할 수 있는 위벽효과 연구를 수행하였다. 우선 공동수조의 실험에서 프로펠러의 상류가 아닌 작동 평면 위치에서 계측된 유속을 프로펠러 전진속도로 정의할 경우, 위벽효과의 수정 량 및 단독특성차이가 현저히 줄어드는 것을 확인하였다. 다음으로 양력판 이론에 의한 단독특성 계산을 통해, 프로펠러 평면에서의 위벽효과를 구하고 앞의 결과에 추가적인 보정을 수행하였다. 그 결과, 예인수조에서의 단독특성과 더욱 더 좋은 일치를 보여 주는 것을 확인하였다.

• 한국자동차공학회논문집
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• 제10권4호
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• pp.15-22
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• 2002

As the emission regulations on the automobiles have been increasingly stringent, precise control of air/fuel ration is one of the most important issues on the gasoline engines. Although many researches have been carried out to identify the fuel transport phenomena in the port fuel injection gasolines, mixture preparation in the cylinder has not been fully understood due to the complexity of fuel film behavior, In this paper, the mixture preparation during cold engine start is studied by using a Fast Response Flame ionization Detector.(FRFID) In order to estimate the transportation of injected fuel from the intake port into cylinder, the wall wetting fuel model was used. The two coefficient($\alpha$,$\beta$) of the wall-wetting fuel model was determined from the measured fuel mass that was inducted into the cylinder at the first cycle after injection cut-in. $\alpha$( ratio of directly inducted fuel mass into cylinder from injected fuel mass) and $\beta$ (ratio of indirectly inducted fuel mass into cylinder from wall wetted fuel film on the wall) was increased with increasing cooling water temperature. To reduce a air/fuel ratio fluctuation during cold engine start, the appropriate fuel injection rate was obtained from the wall wetting fuel model. Result of air/fuel ratio control, air/fuel excursion was reduced.