• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2003.09a
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• pp.461-466
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• 2003

The rockfall protection fences are installed to reduce rockfall damage in roads side slopes. The energy absorbing capacity of widely used rockfall protection fences is about 50kJ. But in many cases, rockfall protection fences are easily damaged even by a low level of rockfall energy. The objective of this paper is to verify the energy absorbing capacity of rockfall protection fences and investigate the behavior of them by rockfall. The LS-DYNA3D, a finite elements analysis program for dynamic movement of three dimensional objects, is used to perform the numerical simulations In the result, it is shown that rockfall protection fences absorb half of standard absorbing energy or less than it. It is inadquate for the rockfall protection fences to perform the principal function. To improve the performance of the fences, new rockfall proctection fence is proposed and numerical simulation is performed.

• Current Photovoltaic Research
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• v.10 no.4
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• pp.116-120
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• 2022

Solar energy is rapidly being utilized to generate power in Europe and other countries, but the environmental effect of building and operating solar farms is not fully understood. The building of a solar park demands the removal of certain vegetation and the leveling of the land. Solar energy infrastructure may involve considerable landscape change, altering soil biological processes and influencing hydrologic, carbon and vegetative dynamics. To rebuild the solar PV facilities soils, inherent plant fields might require to be re-established. Within the scope of this research, we presented an analysis of the effects that were caused by the solar farm.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.11a
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• pp.866-867
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• 2023

기존의 무인 경로 로봇 시스템은 지형 제약과 높은 가격으로 인해 범용성에 한계를 갖는다. 이러한 한계를 극복하기 위해 철조망 위를 자율 주행하는 로봇 시스템(FPS, Fence Patrol System)을 소개하고, 하드웨어와 소프트웨어 측면에서 FPS 의 시스템 작동 원리를 설명한다. FPS 는 철조망 위에서 진동이 감지된 지역으로 이동해 객체를 탐지하고 추적하면서 관리자에게 전송한다. FPS 는 다양한 폭을 갖는 철조망 위에서 주행이 가능하고 완만한 곡률이 있는 철조망도 주행할 수 있도록 설계되었다. 이를 통해 지상 무인 경계 시스템의 한계를 해결하고 다양한 분야에 활용될 것으로 기대한다.

• The Journal of the Convergence on Culture Technology
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• v.4 no.3
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• pp.227-233
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• 2018

In recent years, connected car, which has sensors and computers attached to vehicles used to detect the surrounding environment, has been actively studied. However, in order to configure the connected car environment, various sensors and roadside equipments are required to detect the surrounding environment of the vehicle, and also communication techniques for transmitting the collected data are in demands. Therefore, in this paper, the mobile virtual fence that collects and communicates the data of the surrounding environment through the sensor mounted on the mobile device is applied to the vehicles that were released before the connected car service environment was constructed, We propose a mechanism to receive the service and show the possibility through experiment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.1
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• pp.755-761
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• 2015

Temporary fencing is a mandatory installation in construction sites because of environmental regulations and pedestrian safety. Contractors are responsible for the structural integrity of frames. The fence frame composed of a ledger and post is very weak in the out-of-plane direction, which is normally reinforced by diagonal bracing with a sub post. In this study, the location of lateral bracing for the main post was investigated analytically. Three types of frame were suggested and their performance was compared in terms of the maximum moment and deflection. A construction site may be located at city centers or crowed areas, and a contingent accident should be considered. The EOD type was found to be most efficient among the three frames suggested.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.12
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• pp.6504-6513
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• 2013

The result can be summarized as follows. First, the following periodically changing characteristics were examined:roof form(gambrel/hipped-flat-gable), structure of roof and wall(wood-framed-cement masonry-RC-Light iron framed), roof material(thatched-tiled-slate-cement/steel sheet-asphalt/sandwich panel/mortar water-proofing), wall material(clay plaster/lime plastered-dressing tile/bricks-painting on the cement plastering-native stone dressing/siding/tile), fence material(masonry of stone and cement bricks), and courtyard materials(clay and concrete). Secondly, the regionally changing characteristics of those elements, rural housing structure, roof form, roof structure material, wall finishing material, fence and courtyard material in the outer space, differed according to the location of rural housing, i.e.north, middle, south region. The changing characteristics of both the roof structure and wall structure are similar to those of the three regions.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.05a
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• pp.303-307
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• 2009

Secondary flow losses can be as high as $30{\sim}50%$ of the total aerodynamic losses generated in the cascade of a turbine. Therefore, these are important part for improving a turbine efficiency. As well, many studies have been performed to decrease the secondary flow losses. The present study deals with the leading edge fences on a wing-body to decrease a horseshoe vortex, one of the factors to generate the secondary flow losses, and optimizes the shape of leading-edge fence with the shape factors, such as the installed height, length, width, and thickness of the fence as the design variables. The study was investigated using $FLUENT^{TM}$ and $iSIGHT^{TM}$. Total pressure loss coefficient was improved about 7.5 % than the baseline case.

• Wind and Structures
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• v.22 no.5
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• pp.555-571
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• 2016

A hanging-type sand-retaining wall is a very common sand-blocking fence structure used to prevent sand movement. This type of wall is widely used along the Qinghai-Tibet and Gobi desert railways in Xinjiang, Western China. To analyze the characteristics of wind-sand flow fields under the effect of such a sand fence structure, a wind tunnel test and a field test were carried out. The wind tunnel test showed the zoning characteristics of the flow fields under the effect of the hanging-type sand-retaining wall, and the field test provided the sediment transport data for effective wind-proof interval and the sand resistance data in the front and behind the sand-retaining wall. The consistency of the wind-sand flow fields with the spatial distribution characteristic of wind-carried sand motion was verified by the correspondences of the acceleration zone in the flow field and the negative elevation points of the percentage variations of the sand collection rate. The spatial distribution characteristic of the field sand collection data further showed the spatial structural characteristic of the sandy air currents under the action of the hanging-type sand-retaining wall and the sand resistance characteristic of the sand-retaining wall. This systematic study on the wind-sand flow fields under the control of the hanging-type sand-retaining wall provides a theoretical basis for the rational layout of sand control engineering systems and the efficient utilization of a hanging-type sand-retaining wall.

• Asian Journal of Turfgrass Science
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• v.7 no.1
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• pp.19-30
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• 1993

Experiments were conducted to investigate propagation, shade tolerance, cold resistance and growth rate of evergreen ground cover plants ; Vinca minor K , Ajuga reptans L., Ophiopogon japonicus ker. f nanus hort , and Hedera helix.. The results were as follows : 1.It is convenient to use the growing case for rice seed to grow and transplant Vinca minor seed-ling. The most proper density of transplanting Vinea was 180 plants per 1m$^2$. At the end of growing season, the coverage came up to 90% The rooting ability of Hedera helix was best to cut from April to May (temperature 15~23˚C). The seedling length of Parthenocissus quinguefohlia were irregular and ranged from 5 cm of 200cm. 2. Ajuga reptans L., Ophiopogon j. and Vinca minor L. grew better under 50% light intensity than full sunlight. Particularly, under full sunlight and aestival high temperature, there were a few withering plants in Ajuga reptans L. , and V Vilica minor L. 3. Of Vinca minor K., Ajuga reptans L. , Ophiopogon japonicus ker. f. nanus hort. and Hedera helix. acclimatized in open field, where temperature was from -7~8˚C. There were few plants had damage in low temperature incubator to -16˚C after field acclimatization. 4.Tendrils of Parthenocissus quinguefolia strongly clung to the wire netting stone fence but intruded into the gap and cranny of the precast concrete fence and so clung to, so that it needed to install the bending net on the precast concrete fence.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.24 no.2
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• pp.71-84
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• 2021

Restoration of DMZ has come up with the discussion on the peaceful use of the DMZ and the conservation plan of the army. In this study, we aim to identify soil characteristics of 108 sites to figure out environmental conditions around the iron fence of DMZ where vegetation has been removed repeatedly. Based on the soil characteristics and climate variables, hierarchy clustering was performed to categorize sites. As a result, we categorized 108 sites into 4 types: middle elevation region, lowland, East coast lowland, other areas. Group of 'other area' is only high in nutrient and clay proportion. Others are in igneous rock and metamorphic rocks with a high proportion of sand and lower nutrients than the optimum range of growth in Korean forest soil. The middle elevation region has a high altitude, low temperature. The east coast lowland has a high temperature in January and low precipitation. The lowland has a low altitude and high temperature. This category provides the environmental condition around the DMZ fence and can be used to select plants for restoration. The restoration project around the DMZ iron fence should satisfy the security of military plans, which means that functional restoration is prior to ecological restoration such as vegetation management under a power line. Additionally, improvement of soil quality and surface stability through restoration projects is required to enhance the resilience of the ecosystem in DMZ.