• 한국환경복원기술학회지
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• 제8권3호
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• pp.1-12
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• 2005

A study on ecological restoration of landfill slope was conducted in Nanjido to compare immediate and long time effect and supply continuous back data for ecological restoration of landfill slope. As a result, all region constructed by SF and CODRA was effective on improving soil environment and preventing slope erosion. In case of former, by adapting flowers the initial scenery was beautifully built however there was tendency that as time passes the introduced plants were being overtaken by native plants thus it was necessary to select plants which are not being overtaken by native plants. In case of latter, by introducing leguminous plants the natural adaptation of plants were moving smoothly.

• 한국전기전자재료학회논문지
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• 제23권6호
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• pp.471-476
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• 2010

This paper has studied dissymmetrical light distribution design using the secondary optics in the simulation. fundamental Lambertian radiation distribution based on LED has been cut off by the secondary optics, and the first surface slope of lens and second surface slope of total reflection area have been calculated through formula. PMMA (the index of refraction: 1.49361) which is material of lens has been selected. critical angle($42.02993^{\circ}$) between Air and PMMA has been calulated by snell's law, and total reflection angle slope has been selected about $16.67^{\circ}$ to occur the total reflection. when the first surface slope and the second surface slope has been set up, Rays of all total reflection area have generated the total reflection. finally, designed LED Module has been estimated by Korean Industrial Standards for LED safety street lighting. dissymmetrical light distribution have been analyzed with reached effect of road illuminance, and average road illuminance which are each 70.6 lx, 40.35 lx, and 25.88 lx have been satisfied with Korean Industrial Standards for LED safety street lighting.

• 한국농공학회지
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• 제42권6호
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• pp.72-82
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• 2000

Many lot of books introduce the methods to calculate the time of concentration, and these are described as various forms of formulas. There are few formulas appropriate for our basin characteristics Therefone, there are problems to make excessive or less estimation when these formulas are used. To solve these problems, comparison of formulas and sensitivity analysis for them were made with converting parameters. Finally, Time of concentration was estimated to derive Application limits for 3 watersheds by standardized formulas. In the case of input parameters analysis, SCS formula has the highest value by the length, Kerby by the height and SCS by the slope, respectively, while Kraven formula has the lowest value among them. Concerning the relative sensitivity by Taylor series, the time of concentration showed the constant effect while increasing of the length and slope, and the length was more sensitive than the slope in parameters. Finally the standardization formula developed in this study was applied to derive application limits for 3 watersheds(total 17 subbasins). In this case, Rziha(8 subbasins) and SCS(9 subbasins) formulas were the most similar to observed data of total 17 subbasins respectively. Application limits were about 300~500$\textrm{km}^2$ area, 30~60km length and under 0.01 slope for Rziha formula and about 100~200$\textrm{km}^2$ area, 10~30km length, and over 0.01 slope for SCS formula, respectively.

• 한국농촌건축학회논문집
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• 제2권1호
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• pp.101-112
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• 2000

Green environment is most important factor to human being taking a side view of psychological aspect. But, as the civilization progresses rapidly, the green environment decreases. At present, various environmentally friendly methods are developed to prevent the ill effect of the concretes. n this study, Ecostone retaining wall method, which is a kind of environmentally friendly block, are used for verifying the application to the slope stability and protection of rural hosing. In case of rural hosing and structure, the height of the slope is not high and additional loading doesn't act on the slope except the gravity loading of housing and structure. From the result of the stability analysis of Ecostone, 3m to 7m Ecostone retaining wall can have an equivalence capacity comparing with the concrete retaining wall. Therefore, Ecostone method can apply to retaining wall with the structural safety and environmentally friendly aspect using the plants and vegetation.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1543-1546
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• 2008

The purpose of this study was to investigate factors affecting the change of tibial posterior slope and introduce a mathematical model which calculate, through 3-dimensional analysis of the proximal tibia, how the angle of the opening wedge along the anteromedial tibial cortex influences the tibial posterior slope and valgus correction when performing a medial open wedge osteotomy. This mathematical model with navigation system can be guidelines which provide surgeons on preoperative and intraoperative measurements to maintain or correct the tibial slope and to obtain the desired valgus correction of the lower limb during an opening wedge osteotomy.

• Wind and Structures
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• 제25권2호
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• pp.157-176
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• 2017

2-edge box girder bridges have been widely used in civil engineering practice. However, these bridges show weakness in aerodynamic stability. To overcome this weakness, additional attachments, such as fairing and flap, are usually used. These additional attachments can increase the cost and decrease the constructability. Some previous researchers suggested an aerodynamically stabilized 2-edge box girder section, giving a slope to the edge box instead of installing additional attachments. However, their studies are limited to only dynamic stability, even though static aerodynamic coefficients are as important as dynamic stability. In this study, focus was given to the evaluation of static aerodynamic response for a stabilized 2-edge box girder section. For this, the slopes of the edge box were varied from $0^{\circ}$ to $17^{\circ}$ and static coefficients were obtained through a series of wind tunnel tests. The results were then compared with those from computational fluid dynamics (CFD) analysis. From the results, it was found that the drag coefficients generally decreased with the increasing box slope angle, except for the specific box slope range. This range of box slope varied depending on the B/H ratio, and this should be avoided for the practical design of such a bridge, since it results in poor static aerodynamic response.

• 한국산림과학회지
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• 제71권1호
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• pp.50-54
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• 1985

경사면(傾斜面)에 생육(生育)하는 굴참나무, 물참나무, 갈참나무, 떡갈나무 천연림(天然林)의 입목경사도(立木傾斜度)에 미치는 여러 인자(因子)의 영향을 측정(測定) 분석(分析)하였다. 입목경사도(立木傾斜度)에 영향을 미치고 있는 인자(因子)는 수종간(樹種間)의 차(差), 입목경사도(立木傾斜度), 방위(方位)였으며, 입목밀도(立木密度)와 수고(樹高)는 입목경사도(立木傾斜度)와는 상관(相關)이 없었다. 인자(因子) 중 수종간(樹種間)의 차(差)가 입목경사도(立木傾斜度)에 가장 크게 영향을 미쳤으며 다음이 사면경사도(斜面傾斜度)였다. 특히 수종(樹種) 중에서는 물참나무가 모든 사면경사도(斜面傾斜度)에서 가장 기울어지는 양상을 나타내었다.

• 한국지반공학회논문집
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• 제19권2호
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• pp.123-133
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• 2003

사면안정 신뢰성 해석을 통해 다양한 불확실성을 체계적으로 모델링할 수 있는 실용적 인 확률통계 기법을 제시한다. 새로운 제안식은, 지반성질의 확률적 특성화를 위해 공간적 변화와 공간평균으로 인한 분산감소뿐만 아니라 통계 및 측정오차까지도 고려하였다. 지진하중의 불확실성은 인공지진파를 대량으로 생성하고 이를 응답해석에 이용함으로써 반영하였다. 예제 해석결과, 한반도와 같이 지진이 활발하지 않은 지역(중약진 지진대)에서는 일반적 수준의지반성질 변화특성화가 지진위험도 특성화만큼이나 사면 파괴 위험도와 과도한 사면변형 계산값에 영향을 준다는 결론에 도달하였다.

• Geomechanics and Engineering
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• 제28권1호
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• pp.77-87
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• 2022

Many geotechnical analyses require the investigation of water flow within partially saturated soil zone to incorporate the effect of climatic conditions. It is widely understood that the hydraulic properties of the partially saturated soil should be included in the transient seepage analyses. However, the characteristics of dual porosity soils with dual-mode water retention curve are normally modelled using single-mode mathematical equation for simplification of the analysis. In reality, the rainwater flow can be affected significantly by the dual-mode hydraulic properties of the soil. This paper presents the variations of safety factor for dual porosity soil slope with dual-mode water retention curve and dual-mode unsaturated permeability. This paper includes the development of the new dual-mode unsaturated permeability to represent the characteristics of soil with the dual-mode water retention curve. The finite element analyses were conducted to examine the role of dual-mode water retention curve and dual-mode unsaturated permeability on the variations of safety factor under rainfall loading. The results indicate that the safety factor variations of dual porosity soil slope modelled using the dual-mode water retention curve and the unsaturated permeability equation are lower than those of dual porosity slope modelled using single-mode water retention curve and unsaturated permeability equations.

• 한국지반공학회논문집
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• 제23권3호
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• pp.51-59
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• 2007

다양한 불확실성을 체계적으로 반영하는 신뢰성 기반 해석기법을 사면안정 해석의 한 형식으로 제시한다. 통계오차, 공간 변동성, 그리고 공간 평균의 효과를 고려할 수 있는 지반특성 표현식이 사용되었다. 여러 가지 형식의 지반특성 표현식을 이용하여 사면안정 신뢰성 해석을 수행한 결과 통계오차, 공간적 상관성, 그리고 조건부 해석기법을 사용할 경우가 기존의 단순 확률변수 기법에 비해 상당히 작은 파괴확률을 제시한다는 사실이 밝혀졌다. 이 결과는 사면안정 해석에서 공간적 변동성과 통계오차가 합리적으로 고려되어야 한다는 점을 제시한다.