• 한국농공학회지
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• 제18권3호
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• pp.4195-4205
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• 1976

The purpose of this study is to evaluate the existing methods for calculating or estimating the consumptive use (Evaportranspiration) of any agricutural development project area. In determing the consumptive use water in the project area, there will require the best way for estimating irrigation requirement. Many methods for computing the evaportranspiration have been used, each of them with its merits and demerits at home and abroad. Some of these methods are listed as follows: 1.The Penman's formula 2.The B1aney-Criddle method 3.The Munson P.E. Index method 4.The Atmometer method 5.The Texas Water Rights Commission (TWRC) method 6.The Jensen-Haise method 7.The Christiasen method Therefore, the authors will introduce the more widely used method for calculating Consumptive Use by G.H. Hargreaves. The formula is expressed in the form Ep= K·d·T (1.0-0.01·Hn) Hn=1.0+0.4H+0.005H2. This method was adopted for the first time to determine the Irrigation requirements of Ogseo Comprehensive Agricultual Development project (Benefited area:100,500ha) in Korea. This method is presented in somewhat greater detail than the others. Formula is given for the computation of evaportranspiration (with various levels of data availability) Sampel computation of irrigation requirements for Ogseo irrigation project is included. The results and applied materials are summarized as follows. 1. In calculating the Hargreaves formula, the mean temperature relative, humidity, length of day, and percentage of sunshine from three stations of Iri, Jeonju, and Gunsan were used. 2. Monthly evaporation values were calculated by using the formula. 3. Meteological data from the three stations records for the ten years (1963∼1972) were used. 4. The annual irrigation requirements is 1,186mm per hectare, but the case to consider effective rainfall amount takes the annual irrigation demand being 700mm per hectare.

• 한국농공학회지
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• 제25권2호
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• pp.42-53
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• 1983

In Korea, the demand for water is increasing greatly due to Korea's raqid economic progress which is similar to Japan's. A correct estimation of the runoff factors is the question that must be settled first to establish the appropritae plans for water use and water resources. of these plans the estimation of catchment evapotranspiration for every river basin is the subject of the most importance. It is impossible theoretically to measure evapotranspiration directly, because it is an at mospheric translatory phenomenon. Many approaches have been devised to estimate evapotranspiration, but each of these methods estimates from information taken from a specified point, and these methods are considered incomplete for estimating catchment evapotranspiration. In this paper, the seasonal evapotranspiration estimating method that was proposed by Linsly and was applied in the Kamigamo exprimental basin (subjected to Kyoto Univ.) by Takase et al, was used for the Geum river which is the main river in Korea. Conclusion of experiment. 1) The average annual Ec in this river basin from 1966 to 1972 was 470mm. That is considered appropriate since the average value for the six other large river basin in korea was 485mm. 2) The Ec/Ep and Ec/Epm ratios were 0.43 and 0.52, respectively (Ec : estimated evapotranspiration by water balance method, Ep : average pan evaporation, Epm : evaporation by Penman method). The seasonal Ec/Ep ratios were : 0.4 in spring, 0.6 in summer, 0.4 in autumn and 0.2 in winter. These are rather small when compared to Japan's or England's. 3) The reason for this was that the precipitational difference in wet and dry seasons were greater, an there was not sufficient soil moisture harmonize with the evapotranspiration capacity in the dry season, and that evapotranspiration was small due to the numerous barren mountains.

• 한국물환경학회지
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• 제20권4호
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• pp.376-381
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• 2004

The use of electron beam irradiation was investigated to disinfect total coliforms in the secondary sewage treatment effluent. Unchlorinated secondary effluent was irradiated at different dose of 0.2~1.0 kGy by 1 MeV, ELV-4 Model electron beam accelerator. It is interesting to note that a 100 % reduction in total coliforms and total colonies were achieved until a dose of approximately 0.8 kGy. Even at low dose of 0.2 kGy, the total coliforms and total colonies were successfully inactivated to the level of satisfying the new effluent discharge guideline. Besides disinfection of total coliforms, approximately a 50% removal in biochemical oxygen demand was pronounced at a dose of 0.2 kGy. More than 20 % removal in suspended solids and turbidity was also observed at a dose of 1.0 kGy. The application of electron beam irradiation appeared to be one of options to reuse sewage treatment effluent as agricultural or industrial water.

• 한국수자원학회논문집
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• 제32권2호
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• pp.197-210
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• 1999

본 연구는 추계학적 과정을 고려함으로써 연유출의 핵심적 통계치를 한발 확률 분포에 관련된 통계치로 유도하는데 사용하여 재현 기간과 물 수요의 다양한 조합에 대하여 한발 기간과 누가부족유출량을 산정함으로써 한발의 심각성을 검토하였다. 초기 단계에선는 기록기간, 기록의 질을 특정 기준에 적합한 것으로 판정된 우리 나라의 하천 관측 기록의 분석을 실시하고 분석에 의하여 선택된 하천의 연속 한발에 대한 추계학적 형태를 정의하는데 필요한 연유량을 결정하였다. 앞의 연구 결과를 사용하여 연속 이론을 적용함으로써 실제 또는 추정된 연유량 통계치를 최대 한발 사상의 확률 분포와 연관시켰다. 이 결과로 계측 지점에서의 한발 사상에 재현 기간을 부여할 수 있었으며 한발 기록의 확률 평가가 가능하였다.

• 한국수자원학회논문집
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• 제54권11호
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• pp.969-983
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• 2021

수문기상인자 중 하나인 증발산은 수자원 계획 및 관리 시 고려되며, 특히 물수지모형 등 수문모형의 입력자료로 활용된다. FAO56 PM 방법은 기상인자로부터 기준증발산량(reference evapotranspiration, ET₀)을 추정하며, 상대적으로 높은 정확성을 보여준다. 그러나 FAO56 PM 방법은 많은 기상인자가 필요하기 때문에 증발산 추정에 한계가 있다. 이러한 점에서 온도인자 기반의 Hargreaves 식의 매개변수를 Bayesian 모형을 통해 지역적으로 재추정하여 기준증발산량을 산정하였다. 통계 지표(CC, RMSE, IoA)를 활용하여 모형검증을 수행한 결과, 검증 기간에 대해 RMSE는 7.94 ~ 24.91 mm/month에서 6.77 ~ 12.94 mm/month로 기존 Hargreaves 식으로 추정된 증발산량에 비해 정확도가 크게 개선되었다. 본 연구에서는 산정된 기준증발산량을 활용해 증발 요구량(E₀) 기반의 가뭄지수 EDDI (evaporative demand drought index)를 제시하였다. 가뭄지수로서 적용성을 확인하기 위해 강수량 및 SPI와 함께 최근 2014 ~ 2015년, 2018년 가뭄사상을 평가하였다. 한강유역에 위치한 춘천, 홍천의 2018년 가뭄 발생 당시, 주단위 EDDI가 2 이상까지 증가하였으며, 이를 통해 EDDI가 강수부족보다는 폭염에 대한 반응정도가 큰 것을 확인할 수 있었다. 가뭄지수 EDDI는 SPI와 함께 가뭄 분석 및 평가에 대해 활용성이 높은 것으로 사료된다.

• 조명전기설비학회논문지
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• 제24권1호
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• pp.1-8
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• 2010

본 연구는 최근 친수공간 확대로 수중보의 경관조명 수요가 급격히 늘어나고 있으나 현재 사용하는 수중보 조명등의 안전성과 연출효과가 떨어지는 등 문제점이 발생되므로 수중보 조명등을 개선하기 위해 안전성, 에너지 절감, 연출에 대한 유연성에 주관점을 두고 실태조사를 통한 문제점을 도출 분석하여 수중보조명등을 LED몰드 수중등으로 개발하였다. 본 연구의 결과물을 실용화함으로써 수중보 조명은 댐, 분수, 수영장 등 수변공간에 다양하게 확대 적용 가능할 것으로 사료된다.

• 동력기계공학회지
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• 제21권6호
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• pp.62-67
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• 2017

In order to achieve high efficiency of energy use and environment-friendly architectural design, various loads such as cooling, heating and hot water required by the building sector must be accurately predicted. Many studies used dynamic simulation tool to evaluate and analyze building energy performance. However, there are few studies on the comparative analysis of load results by each simulation and the evaluation of simulation characteristics and functions. In this study, the cooling, heating loads and energy demand of the buildings were evaluated using three dynamic simulations for the building with the same input conditions, and the characteristics of each simulation were compared and analyzed through the results. As a result of simulation comparative analysis, cooling, heating load and energy demand was lowest in square type and north-south direction conditions.

• 펄프종이기술
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• 제31권4호
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• pp.23-29
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• 1999

The effect of dilute sulfuric acid treatment was examined to improve recyclability of coated brokes. Turbidity , electric conductivity , and cationic demand of the white water from coated broke prepared from an alkaline base paper was determined. Sulfuric acid treatment was found to be effective in dissolving undisintegrated substances such as binders, pigments, and fibers. The properties of papers prepared by adding the broke to pulp stock up to 30% dry weight were examined . With the increase of broke addition, retention, sizing degree and smoothness were improved ; on the other hand, formation uniformness, air permeability and internal bonding strength were decreased. The extent of improvement by broke addition was greater for the surfuric acid-treated broke than the control broke. It was concluded that the use of coated broke should be limited within 10-15% weight of the product for either type of broke.

• Corrosion Science and Technology
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• 제7권5호
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• pp.288-295
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• 2008

The increase use of natural gas as an energy source has been continuous demand for ever-increasing strength in gas transmission pipeline materials in order to achieve safe and economic transportation of natural gas. In particular, linepipe material for sour gas service primarily needs to have crack resistant property. However, applications of sour linepipes are expanding toward deep water or cold region, which require higher toughness and/or heavier wall thickness as well as higher strength. To improve the crack resistance of linepipe steel in sour environment, low alloy steel are produced by controlled rolling subsequently followed by the accelerated cooling process. This paper summarizes the design concepts for controlling crack resistant property low alloy linepipe steels for sour gas service.

• 한국농촌건축학회논문집
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• 제21권4호
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• pp.45-52
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• 2019

Chemical grouting method is mainly used for construction of dams and reservoirs, stabilization and reinforcement of slopes, reinforcement of soft grounds such as embankments, dredging and landfills, the order of earthquake response method, and the reinforcement of structures. Recently, it is widely applied in construction sites such as highways, airfields, high-speed railways, subsea facilities, port construction works, tunnels, and subway works. As such, the demand for grouting continues to increase. The development of the grouting method was focused on increasing the strength of the ground, and the development of the chemical additives, the injection device, and the stirring device were mainly performed. But ordinary portland cement used for grouting is a product that consumes natural resources such as limestone, generates a large amount of greenhouse gases, consumes a large amount of energy sources, and it is time to develop products and new methods to replace them. In this study, Ordinary Portland Cement and New Grouting Binder (circulating fluidized bed boiler fly and blast furnace slag) were compared and analyzed by the following test. Homo-gel strength and homo-gel time, water quality analysis of the water used and soil contamination process tests of homo-gel samples were performed. In the case of NGB, when Using water is used as the reservoir water, the strength measured smaller than that of the other water. However, it shows about 2.5 times greater than the homo-gel compressive strength applied to OPC (7-day, reservoir water), so there is no problem with water quality when applied.