• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2020년도 학술발표회
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• pp.85-85
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• 2020

South Korea experiences few large scale erosion and sedimentation problems, however, there are numerous local sedimentation problems. A reliable and consistent approach to modelling and management for sediment processes are desirable in the country. In this study, field measurements of sediment concentration from 34 alluvial river basins in South Korea were used with the Modified Einstein Procedure (MEP) to determine the total sediment load at the sampling locations. And then the Flow Duration-Sediment Rating Curve (FD-SRC) method was used to estimate the specific degradation for all gauging stations. The specific degradation of most rivers were found to be typically 50-300 tons/㎢·yr. A model tree data mining technique was applied to develop a model for the specific degradation based on various watershed characteristics of each watershed from GIS analysis. The meaningful parameters are: 1) elevation at the middle relative area of the hypsometric curve [m], 2) percentage of wetland and water [%], 3) percentage of urbanized area [%], and 4) Main stream length [km]. The Root Mean Square Error (RMSE) of existing models is in excess of 1,250 tons/㎢·yr and the RMSE of the proposed model with 6 additional validations decreased to 65 tons/㎢·yr. Erosion loss maps from the Revised Universal Soil Loss Equation (RUSLE), satellite images, and aerial photographs were used to delineate the geospatial features affecting erosion and sedimentation. The results of the geospatial analysis clearly shows that the high risk erosion area (hill slopes and construction sites at urbanized area) and sedimentation features (wetlands and agricultural reservoirs). The result of physiographical analysis also indicates that the watershed morphometric characteristic well explain the sediment transport. Sustainable management with the data mining methodologies and geospatial analysis could be helpful to solve various erosion and sedimentation problems under different conditions.

• 대한토목학회논문집
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• 제29권5A호
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• pp.551-555
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• 2009

본 연구는 도로터널 내 화재시 콘크리트 구조체의 내화성능을 평가하기 위한 기준을 제시하고자 실시하였다. 현재 국내에서는 지형특성 및 환경친화적인 도로건설로 도로 터널의 수가 빠른 속도로 증가하며, 터널연장이 길어짐에 따라 터널 내 화재사고가 갈수록 높아지고 있는 상황이다. 하지만 우리나라에서는 터널 화재에 대한 적합한 시간-온도 곡선을 규정하지 못하고 있는 실정이다. 따라서 본 연구에서는 국내 도로의 통행량, 차량 종류등을 고려한 열방출율을 기초로 외국에서 제시된 시간-온도 곡선을 검토해 보았으며 적합한 설계화재 모델을 적용하였다. 또한 적용된 도로터널의 설계화재모델에 따른 수치해석을 통하여 터널 구조체의 화재시 성능을 검토하였다.

• 지질공학
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• 제30권4호
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• pp.649-661
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• 2020

도로비탈면관리시스템은 전국 도로 비탈면 현황을 파악하고 위험등급을 산정하여 유지대책 선정 및 사전에 비탈면 붕괴를 차단하여 국민의 안전을 도모하기 위해 만들어졌다. 이를 위해 전국 국도에 위치한 깎기비탈면에 대해 기초·정밀조사를 수행하여 데이터베이스를 구축하고 매년 갱신되고 있다. 수집된 데이터는 수치형과 문자형으로 구성되어 있으며, 사면에 대한 객관적인 정보와 전문가의 판단에 의해 결정된 주관적인 정보로 구성되어 있다. 본 연구에서는 도로비탈면관리시스템에서 관리하는 데이터 활용 가능성을 검토하기 위해, 기계학습인 로지스틱 회귀분석을 이용하여 독립적인 정보를 이용한 주관적 정보 예측 모델을 구축하고 검증하였다. 수행결과, 구축된 확률모델을 이용하여 높은 정확도로 주관적 판단이 필요한 정보들을 예측할 수 있음을 확인하였다. 또한, 구축된 모델을 활용하여 새로 수집된 정보와 모델로부터의 예측값을 비교 ? 검토를 통해 고품질의 데이터를 구축할 수 있을 것으로 기대된다.

• 대한토목학회논문집
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• 제13권1호
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• pp.213-220
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• 1993

본 논문에서는 해마다 수 십만 개씩 발생되는 폐타이어의 열적 처리 방법인 건류 소각 처리 방법에서 발생되는 이차 오염 물질을 정량하여 폐타이어의 안전한 최종 처리 방법까지 고찰하였다. 건류-소각처리 방법에서 발생되는 배기 가스에서 이차 독성 오염 물질을 화학 평형 모델을 응용하여 예측하였고 실질적인 잔류 물질인 건류재와 소각재에서 유기성 독성 물질과 중금속을 정량하였다. 건류재에서는 폐타이어의 불완전 연소에 따른 유기성 이차 오염 물질이 다량 포함되어 있는 반면에 소각재에서는 납과 카드뮴과 같은 중금속 화합물의 함량이 높았다. 건류재 및 소각재의 안전한 최종 매립을 위하여는 서로 다른 전처리 방법이 요구된다.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1994년도 춘계공동학술대회논문집; 창원대학교; 08월 09일 Apr. 1994
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• pp.596-605
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• 1994

An efficient measurement and evaluation system for hand tool tasks will provide a practical solution to the problem of designing and evaluating manual tool tasks in the workplace. Few studies on the biomechanical analysis of hand postures and tool handling tasks exist because of the lack of appropriate measurement techniques for hand force. A measurement system for the finger forces and joint angles for analysis of manual tool handling tasks was developed in this study. The measurement system consists of a force sensing glove made from twelve Force Sensitive Resistors and an angle-measuring glove (Cyberglove$\^$TM/, Virtual technologies) with eighteen joint angle sensors. A biomechanical model of the hand using the data from the measurement system was also developed. Systems of computerized procedures were implemented integrating the hand posture measurement system, biomechanical analysis system, and the task analysis system for manual tool handling tasks. The measurement system was useful in providing the hand force data needed for an existing task analysis system used in CTD risk evaluation. It is expected that the hand posture measurement developed in this study will provide an, efficient and cost-effective solution to task analysis of manual tool handling tasks. These tasks are becoming increasingly important areas of occupational health and safety of the country.

• The Journal of Asian Finance, Economics and Business
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• 제7권11호
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• pp.251-257
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• 2020

The study investigates the role of commodity prices and tax purpose recognition on bitcoin prices. Since the introduction of bitcoin in 2008, emphasis has focused on economists, policy-makers and analysts drastically increasing bitcoin's accessibility and commodity values (Dumitrescu & Firică, 2014). This study employs GARCH and EGARCH from ARCH/GARCH family on daily nature data. We measure the volatile behavior of bitcoin by employing auto-regressive conditional heteroscedasticity model with the aim to explore the relationship between major commodities and bitcoin volatility. We focus on major commodities like gold, silver, platinum, and crude oil to be regressed with bitcoin. The daily prices of commodities were retrieved from www.investing.com and bitcoin prices from www.coindesk.com for the period from 29April 2013 to 16 October 2018. Results confirmed the currency's long-term volatile behavior, which is due to its composition and market dynamics, whereas the existence of asymmetric information effect is not confirmed. Tax recognition by other countries may in future help in controlling the volatility as bitcoin is not a country-specific security. But, only silver impacts on volatility in comparison to oil prices and platinum, which is due to its similar features with gold. Eventually, bitcoin can be used for risk diversification and money making.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
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• pp.713-716
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• 2008

본 연구는 도로터널 내 화재시 콘크리트 구조체의 내화성능을 평가하기 위한 기준을 제시하고자 실시하였다. 현재 국내에서는 지형특성 및 환경친화적인 도로건설로 도로 터널의 수가 빠른 속도로 증가하며, 터널연장이 길어짐에 따라 터널 내 화재사고가 갈수록 높아지고 있는 상황이다. 하지만 우리나라에서는 터널 화재에 대한 적합한 시간-온도 곡선을 규정하지 못하고 있는 실정이다. 따라서 본 연구에서는 국내 도로의 통행량, 차량 종류등을 고려한 열방출율을 기초로 외국에서 제시된 시간-온도 곡선을 검토해 보았으며 설계화재 모델을 제시하였다.

• Earthquakes and Structures
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• 제9권5호
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• pp.1069-1089
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• 2015

This paper investigates the limits and efficacies of the Fiber Reinforced Polymer (FRP) material for strengthening mid-rise RC buildings against seismic actions. Turkey, the region of the highest seismic risk in Europe, is chosen as the case-study country, the building stock of which consists in its vast majority of mid-rise RC residential and/or commercial buildings. Strengthening with traditional methods is usually applied in most projects, as ordinary construction materials and no specialized workmanship are required. However, in cases of tight time constraints, architectural limitations, durability issues or higher demand for ductile performance, FRP material is often opted for since the most recent Turkish Earthquake Code allows engineers to employ this advanced-technology product to overcome issues of inadequate ductility or shear capacity of existing RC buildings. The paper compares strengthening of a characteristically typical mid-rise Turkish RC building by two methods, i.e., traditional column jacketing and FRP strengthening, evaluating their effectiveness with respect to the requirements of the Turkish Earthquake Code. The effect of FRP confinement is explicitly taken into account in the numerical model, unlike the common procedure followed according to which the demand on un-strengthened members is established and then mere section analyses are employed to meet the additional demands.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2019년도 학술발표회
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• pp.148-148
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• 2019

The 2006 Millennium Ecosystem Assessment (MA) defines ecosystem services (ES) as "the benefits people obtain from ecosystems". Identifying where ES originates, whom it benefits and how it is changing over a period of time is critical in rapidly developing country like Nepal, where the risk of ES loss is high. In the context of various ecosystem services provided by watershed, this study, particularly deals with water yield, Soil loss and Carbon sequestration computation and evaluation in Bagmati Basin of Nepal. As Bagmati Basin incorporates capital city Kathmandu of nepal, land use change is significant over decades and mapping of ES is crucial for sustainable development of Basin in future. In this regard, the objectives of this study are 1) To compute the total and sub-watershed scale water yield of the basin, 2) Computation of soil loss and sediment retention in the basin, and 3) Computation of carbon sequestration in the basin. Integrated Valuation of Environmental Services and Tradeoffs (InVEST), a popular model for ecosystem service assessment based on Budyko hydrological method is used to compute Ecosystem services. The scenario of ES in two periods of time can be referenced for various approaches of prioritization and incorporation of their value into local and regional decision making for management of basin.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2019년도 학술발표회
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• pp.146-146
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• 2019

The aridity index, which is determined as the ratio of potential evapotranspiration to precipitation, is one of key parameters in drought characterization. Whereas the evaporative index, which is defined as the ratio of actual evapotranspiration to precipitation, represents the fraction of available water consumed by the evapotranspiration process. This study investigates variation of the aridity and evaporative indexes due to climate change during the 21st century in South Korea. Estimations of the aridity and evaporative indexes are obtained using SWAT mode based on ensemble of 13 different GCMs over 5 large basins of South Korea for 2 RCP scenarios (RCP 4.5 and RCP 8.5). The results shows the opposite trends of the two indexes, where the aridity index is projected as always increase, while the evaporative index is expected to decrease in all of 3 future period (2011-1940, 1941-1970, 1971-2099). The estimated results also suggest that land cover influenced significantly evapotranspiration along with the change of climate. The study indicates that South Korea will be facing with a high risk of water scarcity in future due to climate change, which is seriously challenging for water planing and management in the country.