• Wind and Structures
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• 제32권2호
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• pp.115-126
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• 2021

The snow cornice mass on the formation zone had triggered avalanches which led to the loss of human life and property. Snow cornice is formed due to flow separation on the leeward side. Effect of lee slope is more prominent in the formation of snow cornices as compared to the windward slope. The analysis of wind flow pattern has been carried out to evaluate the performance of a jet roof. Computational Fluid Dynamics (CFD) analysis of wind flow over a 2D hill model was carried out using RNG based k-∈ turbulence models available in ANSYS Fluent. Effect of varying leeward hill slope (1:2 to 1:6) on flow separation for the given windward slope was observed and a critical slope of 1:4 was found at which the separation zone ceased to exist. The modification of wind flow over a hill due to the installation of jet roof was simulated. It was observed that jet roof had significantly modified the wind flow pattern around hill ridgeline and ultimately snow cornice formation had mitigated. The results of the wind flow pattern were validated with the wind data collected at the experimental site, Banihal Top (Jammu and Kashmir, India). The wind flow simulation over the hill and mitigation of cornice formation by the jet roof has been explained in the present paper.

• Wind and Structures
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• 제36권2호
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• pp.75-90
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• 2023

Turbulent wind flow over hilly terrains has been extensively investigated in the scientific literature and main findings have been included in technical standards. In particular, turbulent wind flow over nominally two-dimensional hills is often adopted as a benchmark to investigate wind turbine siting, estimate wind loading, and dispersion of particles transported by the wind, such as atmospheric pollutants, wind-driven rain, windblown snow. Windblown sand transport affects human-built structures and natural ecosystems in sandy desert and coastal regions, such as transport infrastructures and coastal sand dunes. Windblown sand transport taking place around any kind of obstacle is rarely in equilibrium conditions. As a result, the modelling of windblown sand transport over complex orographies is fundamental, even if seldomly investigated. In this study, the authors present a wind-sand tunnel test campaign carried out on a nominally two-dimensional sinusoidal hill. A first test is carried out on a flat sand fetch without any obstacle to assess sand transport in open field conditions. Then, a second test is carried out on the hill model to assess the sand flux overcoming the hill and the morphodynamic evolution of the sand sedimenting over its upwind slope. Finally, obtained results are condensed into a dimensionless parameter describing its sedimentation capability and compared with values resulting from other nominally two-dimensional obstacles from the literature.

• Asian-Australasian Journal of Animal Sciences
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• 제14권7호
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• pp.956-959
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• 2001

Three perennial grasses, Napier (Pennisetum purpureum), Andropogan (Andropogan gayanus) and Para (Brachiria mutica), were grown at different hill heights dividing the hill slope into three regions (top, middle and bottom). The first two grasses gave the highest biomass yields (29.9 and 37.6 tonnes/ha/harvest, respectively) followed by Para (20.5 t/ha). No significant (p>0.05) changes in biomass yields of the grasses were found due to differences in hill heights. The grasses were harvested three times in the first year of cultivation. Maize and cowpea as sole crops or their intercrops were cultivated in the plain land and the intercrop gave the highest biomass yield (46.7 t/ha, p<0.05). The biomass produced was successfully ensiled in the underground pits at the hill tops.

• 한국주거학회논문집
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• 제13권2호
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• pp.55-64
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• 2002

This study aims at the suggestion of possibility that a housing density will maintain properly and that an ecological hill housing will recover a rapport with the ground. That is, both residential planning on the hillside and ecological architecture as a concept for development are chosen for study category, and relationship between the hillside and the hill housing is theorized and then propriety is analysed through application of the ecological planning elements. The results of this study are as follows: 1. Now that the hillside is regarded as an idle land that preserves natural environment and maintains ecosystem, it must be developed on the basis of awareness that nature and human beings exist together. 2. Analysis of geographical factors must be advanced because it is inevitable that the development of the hill housing should be performed properly to the geographical characteristics. 3. Planning elements of ecological residential block which are possible for constructing on the hillside can be developed and applied, on the basis of geographical characteristics, by classifying them into two areas; housing estate, building and unit.

• 한국전자통신학회논문지
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• 제7권4호
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• pp.789-796
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• 2012

최적 교정률을 보이는 모듈 순서를 찾는 것이 논문의 목적이다. 한국어 맞춤법 교정기의 성능을 분석하기 위하여 등산법을 실험에서 사용하였다. 주어진 오류어절 집합에 대하여 96.41%의 교정률을 나타낸 모듈순서열을 찾았다. 교정률이 상당히 높기때문에, 등산법이 맞춤법 교정기에 대하여 실용적인 방법임을 보였다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 춘계학술대회 논문집
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• pp.275-280
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• 2004

Shape optimization was performed to obtain the precise shape of cutouts including the internal shape of cutouts in laminated composite plates by three dimensional modeling using solid element. The volume control of the growth-strain method was implemented and the distributed parameter chosen as Tsai-Hill fracture index for shape optimization. The volume control of the growth-strain method makes Tsai-Hill failure index at each element uniform in laminated composites under the initial volume. Then shapes optimized by Tsai-Hill failure index were compared with those of the initial shapes for the various load conditions and cutouts. The following conclusions were obtained in this study. (1) It was found that growth-strain method was applied efficiently to shape optimization of three dimensional cutouts in a laminate composite, (2) The optimal shapes of the various load conditions and cutouts were obtained, (3) The maximum Tsal-Hill failure index was reduced up to 67% when shape optimization was peformed under the initial volume by volume control of growth-strain method.

• 대한기계학회논문집A
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• 제28권9호
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• pp.1337-1343
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• 2004

Shape optimization was performed to obtain a precise shape of cutouts including the internal shape of cutouts in a laminated composite plate by three dimensional modeling using solid element. Volume control of the growth-strain method was implemented and the distributed parameter chosen as Tsai-Hill fracture index for shape optimization. It makes Tsai-Hill failure index at each element uniform in laminated composites under the predetermined volume a designer requires. Shapes optimized by Tsai-Hill failure index were compared with those of the initial shapes for the various load conditions and cutouts. The following conclusions were obtained in this study; (1) It was found that growth-strain method was applied efficiently to shape optimization of three dimensional cutouts in a laminate composite, (2) The optimal shapes of the various load conditions and cutouts were obtained, (3) The maximum Tsai-Hill failure indices of the optimal shapes were remarkably reduced comparing with those of the initial shapes.

• 한국정밀공학회지
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• 제26권6호
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• pp.122-130
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• 2009

The analysis of human movement requires the knowledge of the Hill type muscle parameters, the muscle-tendon and moment arm length change as a function of joint angles. However, values of a subject's muscle parameters are very difficult to identify. It turns out from a sensitivity analysis that the tendon slack length and maximum muscle force are the two critical parameters among the Hill-type muscle model. Therefore, it could be claimed that the variation of the tendon slack length and maximum muscle force from the Delp's reference data will change the muscle characteristics of a subject remarkably. A numeric optimization method to search these tendon parameters specific to a subject is proposed, and the accuracy of the developed algorithm is evaluated through a numerical simulation.

• 대한원격탐사학회지
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• 제1권1호
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• pp.89-97
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• 1985

Hill-Sliding Clustering이라는 다변량 자료의 무감독 분류 방법을 Apple II personal computer의 BASIC언어를 사용한 Algorithm으로 개발하였다. 이 Algorithm으로 다변량 multimode를 갖는 정규 분포 자료에서 사전 지식없이 자료를 집단화하여 구분해 낼 수 있게 되 었다. 한국 연안 지역의 Landsat(지구 자원 탐사 위성)의 다중, Spectrum 영상 자료에 적용한 시 험 결과, 매우 고무적 결론을 얻었다.

• 한국작물학회지
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• 제25권1호
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• pp.87-91
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• 1980

대두의 신육형이 다른 유한형품종 동북태, 수원8003, 광교와 무한형품종 Harosoy, Columbusp Clark 63, Hill을 공시하여 3회 제초. 6적후 1회 제초와 잡초방임 조건에서 잡초와의 경합력에 대한 대두 품종간 차이를 조사하였다. 1. 잡초의 수량은 잡초와의 경합력이 약하였던 대두품종 Columbus, Harosoy와 Hill에서 현저히 높았다. 2. 잡초와의 경합에 의하여 분지수와 협수가 감소되었으며 무한형품종 Columbus ,Harosoy와 Hill에서 그 경향이 현저하였다. 3. 대두의 수량은 잡초방임구에서 잡초에 대한경합력이 약하였던 무한형품종 Columbus는 42%, Harosoy는 39%,Hill은 35% 감수되있으나 유한형품종 수원 8003와 동북태는 수량감소가 적었다.