• 한국자동차공학회논문집
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• 제3권5호
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• pp.135-142
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• 1995

This paper presents the effect of the component performance for mat supported monolithic cordierite ceramic underflow catalytic converters to meet the new stringent durability requirements of the world's. These objectives are met by a conceptional system approach of mat mounting material with stainless steel can(shall), and heatshield(cover), which are related to the mat erosion, a main failure pattern of the mat supported monolithic ceramic catalytic converters. In this paper we study the individual component behavior of mat erosion problem, After studying, we obtain the characterics of the component performance for automotive catalytic converters and the overall understanding of design considerations in catalytic converters.

• 한국농공학회논문집
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• 제54권1호
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• pp.99-108
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• 2012

Soil erosion and sediment from agricultural farmland has caused various negative impacts on environment in recent years. The effect of rice straw mat on soil erosion has been investigated by many researchers these days. In this study, the SWAT model was applied to Hongcheon watershed to evaluate SWAT flow and sediment, and the effect of rice straw mat on sediment yield at watershed outlet was evaluated. The Nash-Sutcliffe model efficiency (NSE) and coefficient of determination ($R^2$) values for flow simulation (calibration period) were 0.66 and 0.67, and the NSE values for sediment was 0.90. The calibrated parameters were used to analyze the reduction of sediment yield in the farmland with rice straw mat. Average daily sediment yield without rice straw mat was 49.8 ton/day and sediment yield with rice straw mat was 25.5 ton/day, and the reduction rate was 38.7 %. Also, average daily sediment yield with/without rice straw mat were 97.5 ton/day and 190.7 ton/day during the rainy season (Jun. 2008 - Aug. 2009), with the reduction rate 46.3 %.

• 한국환경복원기술학회지
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• 제7권1호
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• pp.77-84
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• 2004

This study was conducted to suggest vegetation mat forming methods with native wildflowers, introduced wild flower, grasses and native herb plants which can be used for erosion control of the disturbed slopes. The main results are summarized as follows. In forming the vegetation mat at early stage, foreign grasses, native wild plants shows more effective than the other seed mixture types. But, after 12 weeks, using native wild flowers shows more effective than foreign grasses. Also, the mixture of the native grasses and kentucky bluegrasses (seed mixture type F) are the best in ground coverage among the seed mixtures types. In order to restore slopes more naturally, more diverse plants should be used. The native grasses such as Marrubium incisum Bentham, Lutos comiculatus L. var. japonicus Regel, and Artemisia princeps Pampan seems to be useful to forming the vegetation mat, also it will be more easy if mixing with foreign grasses such as Kentucky bluegrass. The mixture of native grasses and introduced wild flowers are not proper in forming the vegetation mat. Also, pot planting of the native grasses are not proper in forming the vegetation mat.

• Ecology and Resilient Infrastructure
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• 제6권4호
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• pp.217-226
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• 2019

본 연구에서는 하천의 하안 경사와 친수시설 유무에 따라 적절한 하안 보호 공법을 유형화하였으며, 특히 기존의 호안 공법으로 하안침식 방지 대책 적용이 적절하지 않은 유형에 대해 적용 가능한 신개념 Eco-hybrid 롤링매트 공법을 제시하였다. Eco-hybrid 롤링매트 공법은 지반과 사면의 교란없이 하천 환경과 생태 조건의 변화를 최소화하는 시공이 가능하고, 하안침식이 발생할 경우 즉각적인으로 호안이나 제방 사면을 보호할 수 있는 경제적이고 효율적인 공법이다. 개발된 Eco-hybrid 롤링매트 공법은 실규모 하천 실험을 통해 공법의 구조 및 시스템, 기능과 효과를 검증하였다. 현장에서 발생할 수 있는 여러 변형 및 부패 테스트를 포함한 실규모 하천 실험 검증을 수행하였으며, 저유속과 고유속 조건에서 롤링매트의 작동과 하안침식 방지 효과를 확인하였다. 하안침식 방지 효과는 유사 농도 분석을 통해 정량적으로 검증하였으며, 실험에 활용한 롤링매트를 기준으로 규격화하여 Eco-hybrid 롤링매트 공법의 제품의 시방 (안)을 제시하였다.

• 한국농공학회논문집
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• 제52권3호
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• pp.97-104
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• 2010

The purpose of this study is to evaluate sediment yield reduction under various field slope conditions with rice straw mat. The Vegetative Filter Strip Model-W (VFSMOD-W) and Soil and Water Assessment Tool (SWAT) were used for simulation of sediment yield reduction effect of rice straw mat. The Universe Soil Loss Equation Practice factor (USLE P factor), being able to reflect simulation of rice straw mat in the agricultural field, were estimated for each slope with VFSMOD-W and measured soil erosion values under 5, 10, and 20 % slopes. Then with the regression equation for slopes, USLE P factor was derived and used as input data for each Hydrological Response Unit (HRU) in the SWAT model. The SWAT Spatially Distributed-HRU (SD-HRU) pre-processor module was utilized, moreover, in order to consider spatial location and topographic features (measured topographic features by field survey) of all HRU within each subwatershed in the study watershed. Result of monthly sediment yield without rice straw mat (Jan. 2000 - Aug. 2007) was 814.72 ton/month, and with rice straw mat (Jan. 2000 - Aug. 2007) was 526.75 ton/month, which was reduced as 35.35 % compared without it. Also, during the rainy season (from Jun. to Sep. 2000 - 2007), when without vs. with rice straw mat, monthly sediment indicated 2,109.54 ton and 1,358.61 ton respectively. It showed about 35.60 % was reduced depending on rice straw mat. As shown in this study, if rice straw mat is used as a Best Management Practice (BMP) in the sloping fields, rainfall-driven sediment yield will be reduced effectively.

• 한국물환경학회지
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• 제30권6호
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• pp.638-646
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• 2014

Soil erosion from agricultural fields leads to various environmental problems weakening the capabilities of flood control and ecosystem in water bodies. Regarding these problems, Ministry of Environment of South-Korea prepared various structural and non-structural best management practices (BMPs) to control soil erosion. However, a lot of efforts are required to monitor and develop BMPs. Thus, modeling techniques have been developed and utilized for these issues. This study estimated the effectiveness of BMPs which are a vegetation mat with infiltration roll and Roll type vegetation channel using Soil and Water Assessment Tool (SWAT) model through the adjustment of the conservation practice factors, P factors, for Universal Soil Loss Equation which were calculated by monitoring data collected at the segment plots. Each BMP was applied to the areas with slopes ranged from 7% to 13% in the Haeanmyeon watershed. As a result of simulation, the vegetation mat with infiltration roll and Roll type vegetation channel showed 55% and 59% efficiency of soil erosion reduction, respectively. Also, Vegetation mat with infiltration roll and Roll type vegetation channel showed each 11.2% and 11.8% efficiency in reduction of sediment discharge. These roll type vegetation channel showed greater efficiency of soil erosion reduction and sediment discharge. Based on these results, if roll type vegetation channel is widely used in agricultural fields, reduction of soil erosion and sediment discharge of greater efficiency would be expected.

• Journal of Advanced Research in Ocean Engineering
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• 제1권1호
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• pp.1-13
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• 2015

Post-Katrina investigations revealed that most earthen levee damage occurred on the levee crest and landward-side slope as a result of either wave overtopping, storm surge overflow, or a combination of both. In this paper, combined wave overtopping and storm surge overflow of a levee embankment strengthened with high performance turf reinforcement mat (HPTRM) system was studied in a purely Lagrangian and meshless approach, two-dimensional smoothed particle hydrodynamics (SPH) model. After the SPH model is calibrated with full-scale overtopping test results, the overtopping discharge, flow thickness, flow velocity, average overtopping velocity, shear stress, and soil erosion rate are calculated. New equations are developed for average overtopping discharge. The shear stresses on landward-side slope are calculated and the characteristics of soil loss are given. Equations are also provided to estimate soil loss rate. The range of the application of these equations is discussed.

• 한국산림과학회지
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• 제27권1호
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• pp.5-14
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• 1975

인공적(人工的)인 땅까기 흙쌓기 비탈면을 포함하는 민둥산 비탈면에서의 토양침식(土壤浸蝕)을 방지(防止)을 지피식생조성(地皮植生造成)을 조기(早期)에 확실(確實)히 달성(達成)할 수 있는 새로운 속성녹화공법(速成綠化工法)으로서 개발(開發)된 거적덮기 공법(工法)에 사용(使用)되는 거적의 적성조립밀도범위(適正組立密度範圍),를 결정(決定)하고 동시(同時)에 각급(各級) 밀도(密度)의 효과(效果)를 시험(試驗)한 결과(結果)는 다음과 같이 요약(要約)될 수 있다. 1. 타표류거수(他表流去水)의 유출율(流出率)에 있어서는 거적의 피복율(被覆率)이 90%구(區)(밀연피복구(密筵被覆區))에서 13.3%로 가장 적고, 70%구(區)(중연피복구(中筵被覆區))에서 14.21%, 그리고 50%구(區)(소연피복구(疎筵被覆區)) 15.57%로 가장 많었으나 이것은 나지구(裸地區)에서의 30.4%에 비(比)하면 매우 효과적(效果的)인 공법(工法)인 것이다. 2. 토사유실량(土砂流失量)에 있어서는 밀연피복구(密筵被覆區)에서 약(約) 1.24 ton/ha, 중연피복구(中筵被覆區)에서 약(約) 1.33 ton/ha, 그리고 소연피복구(疎筵被覆區)에서 약(約) 1.44 ton/ha으로서 이것은 미국농무성(美國農務省)의 기준(基準)(1.8 ton m/ha)에 비교(比較)하면 매우 효과적(效果的)인 공법(工法)인 것이다. 3. 파종후(播種後) 발아생립(發芽生立) 본수(本數)는 밀연피복구(密筵被覆區)에서 80본(本)으로 가장 적고 중연피복구(中筵被覆區)에서 132 본(本), 그리고 소연피복구(疎筵被覆區)에서 121 본(本)이었는데, 밀연피복구(密筵被覆區)에서는 발아후(發芽後) 생육중(生育中)에 피복고사율(被覆枯死率)이 높았다. 4. 유수유토발생(流水流土發生) 및 식생조성효과(植生造成効果)를 종합(綜合)해 볼때에 거적덮기공법(工法)에 사용(使用)되는 거적의 조립밀도(組立密度)는 70%내외(內外)가 적정(適正)할 것이다. 5. 본(本) 공법(工法)은 민둥산비탈면에 대한 속성녹화공법(速成綠化工法)으로서는 가장 효과적(效果的)인 피복공법(被覆工法)으로서, 우리나라의 산지사방행정면(山地砂防行政面)에서 대대적으로 여장(勵將)되어야 할 신공법(新工法)인 것이다.

• 한국환경복원기술학회지
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• 제6권2호
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• pp.78-88
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• 2003

This study was conducted to develop the plant-mat for ecological restoration which was formed as the thin multi-layers of woven nets, soil media, seeds, etc. The experimental site was selected at a slope of 240$m^2$ at the rear of Design College of Sangmyung University and divided into 8 sub-experimental plots (20$m^2$ each) according to mat types. (forest-type and grass-type mats with and without seed attachment, respectively) Also, the existing vegetation plot and the no-treatment plot were included in this experiment for comparison. The experiment construction was conducted on September 3, 2002. Mat covered plots regardless of seed attachment showed nearly no signs of erosion even if rainy season in summer compared to the no-treatment plot. Vegetation monitoring result showed that germination rates were somewhat high in both forest and grass-type mats without seed attachment in the initial germination stage. Although germination rates of seed attached mats were somewhat slower than non-seed attached mats in the germination stage, but over time, it showed a good rooting and shooting environment for germinated tree and grass species because of soil media existence within the mat. This indicates that while non seed-attached mats require follow-up maintenance, seed-attached mats does not require maintenance after rooting and germination.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.203-210
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• 2004

Consolidation properties were analysed by means of depositional environments. Depositional environments including geochemical properties, porewater chemistry, sediment structures, particle size distributions and carbon age dating were analysed using undisturbed samples retrieved successively from a boring hole in the study area. Laboratory oedometer tests and anisotropic consolidated triaxial tests(CKoUC) were performed to examine the overconsolidation phenomenons. Based on the carbon age dating results and profiles of geochemical properties, porewater chemistry, salinity and pH, it was founded that the upper silt/clay complex layer was deposited under marine condition while sand and clay layers were deposited under fluvial condition. Planar laminated structures of silts and clays were dominant in marine deposits. Although there was no clear evidences that geological erosion had been occurred in marine deposits, overconsolidation ratio obtained from oedometer tests were greater than unity. Stress paths of samples behaved similar to those of normally consolidated clays. Data plotted in stress state charts proposed by Burland(1990) and Chandler(2000) showed that the marine deposits were geologically normally consolidated. These apparent overconsolidations can be explained by the fabric and chemical bonding due to the difference of the rate of deposition.