• 제목/요약/키워드: Evaluation Equation

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논 물꼬관리 기법 적용에 따른 원단위 삭감부하량 산정식 평가 (Assessing the Unit Load Reduction Equation of Drainage Outlet Raising Management in Paddy Fields)

  • 김동현;오흥근;장태일;함종화
    • 한국농공학회논문집
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    • 제65권2호
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    • pp.35-45
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    • 2023
  • The DOR (Drainage outlet raising) in the paddy field has been suggested as one of the most important best management practices for the TMDL (Total maximum daily load) management in the technical guidelines by the NIER (National institute of environmental research). However, this method is underestimated and is not well adopted by local governments for the TMDL. The purpose of this study is to evaluate the unit load reduction equation according to the application of DOR in order to expand this equation. The original equation in the guideline was derived using the HSPF (Hydrological Simulation Program-Fortran) model for 1 year in Changnyeong. We analyzed the reduction effect of the original equation application by collecting additional long-term monitoring data from the Buan, Icheon, Iksan, and Jeonju. When comparing the reduction loads between the original equation and monitoring results, the evaluation results of the original equation were 11% of the monitoring analysis results, which was underestimated. This means that the original equation needs to be improved. For assessing the equation, the HSPF Paddy-RCH model was established according to the NI ER guideline and evaluated for applicability. The performance results of the model showed a reasonable range by the statistical criteria. Modified equations 1 and 2 were proposed based on the monitoring and modeling results. Modified equation 1 was the method of modifying the original equation's main factors, and modified equation 2 was the method of applying the non-point pollution reduction efficiency according to the rainfall class using the long-term modeling results. At the level of 58.6~64.6% of monitoring data, the difference between them could be further reduced compared to the original equation. The suggested approach will be more reasonable and practicable for decision-makers and will contribute to the TMDL management plans.

비부착 긴장재의 응력을 평가하기 위해 제안된 설계식의 타당성검증 (Verification of Proposed Design Equation for Stress Evaluation of Unbonded Tendons)

  • 임재형;문정호;이리형
    • 콘크리트학회지
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    • 제11권2호
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    • pp.127-137
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    • 1999
  • 본 연구와 관련한 이전의 연구에서는 본 연구자들이 제안한 설계식의 타당성을 검증하기 위하여 선정된 변수별로 실험체를 제작하여 실험을 실시하였고 실험결과를 분석하였다. 본 연구에서는 실험결과에 대하여 본 연구자들이 제안한 설계식과 기존의 설계식들에 의한 해석결과를 비교분석하여 본 연구자들의 설계식의 타당성을 검증하였다. 사용된 기존의 설계식은 현행의 ACI 규준식, AASHTO LRFO 규준시, 변형도 적합조건에 의한 해석식, Harajli/Kanj의 설계식, Chakrabarti의 설계식 등이다. 비교${\cdot}$분석결과에 의하면 본 연구자득이 제안한 설계식이 비부착 긴장재의 응력을 평가하는데 보다 적절한 방법임을 증명하였다.

SEA에 기초를 둔 손실계수를 이용한 결합계수의 평가 (Coupling loss factor evaluation using loss factor based on the SEA)

  • 안병하;황선웅;김영종
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1997년도 추계학술대회 논문집
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    • pp.568-571
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    • 1997
  • The overall aim of this paper is to determine coupling loss factor using loss factor and structural loss factor. For this purpose, two kinds of loss factor were adopted. One is loss factor of each sub structure, another is structural loss factor based on the complex welded or assembled structure. Using these two parameters, it is possible to derive the coupling loss factor which represent characteristic condition of SEA theory. Coupling loss factor of conjunction in complex structure was expressed as power balance equation. The derived equation for a coupling loss factor has been simplified on the assumption of one directional power flow between two sub structures. Using these conditions, it is possible to find the coupling loss factor equation. The comparison between theory of power transmission on conjunction and above equation, show a good agreement in simple beam structure. To check the effectiveness of above equation, it was adopted rotary compressor. Rotary compressor has three main conjunctions between shell and internal vibration part. This equation was applied to find out the optimum welding point with respect to reduce the noise propagation. It shows the effective tool to evaluate the coupling loss factor in complex structure.

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준설매립지반의 액상화 간편예측 개선에 관한 연구 (Improvement Scheme of Simplified Liquefaction Potential Evaluation for a Dredged and Reclaimed Ground)

  • 정민형;김주현;정상국;이송
    • 한국지반공학회논문집
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    • 제23권8호
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    • pp.47-57
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    • 2007
  • 본 연구는 사질토로 준설매립된 지반의 액상화 평가를 위해 반드시 요구되는 초기 밀도특성을 분석하였고, 국내 내진 설계기준에서 제시한 SPT-N을 이용한 액상화 간편예측 방법의 문제점을 분석하여 개선방안을 제시하였다. 기존 시공사례를 토대로 매립 직후 준설매립지반의 밀도특성을 분석한 결과, 상대밀도와 초기 N값은 대체로 각각 $40{\sim}50%,\;5{\sim}8$의 범위에 분포하였다. 액상화 간편예측에 있어서 유효상재압 보정의 Liao & whitman식은 항상 지진에 취약한 상부층이 하부층보다 액상화 저항응력이 크게 산정되어 Skempton식의 적용이 추천된다. 또한, 설계단계에서 준설매립 지반의 심도별 N값을 산정할 경우에는, 유효응력에 따른 N값의 변화를 나타내는 누승함수 $N=1.35{\sigma}^{'0.75}$를 이용하여 액상화 간편예측을 실시할 것을 추천한다.

특허의 내적.외적 가치산정요인을 고려한 입체적 특허평가모델: 아레니우스 화학반응속도론 기반의 특허수명예측 (A three-dimensional patent evaluation model that considers the factors for calculating the internal and external value of a patent: Arrhenius chemical reaction kinetics-based patent lifespan prediction)

  • 최용묵;이재원;조대명
    • 디지털융복합연구
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    • 제19권6호
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    • pp.113-132
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    • 2021
  • 특허수명은 특허가치를 평가하는 척도로 사용되어 왔다. 본 연구에서는 특허수명을 예측하여 개별특허의 가치를 평가함에 있어, 특허의 내적가치요소와 외적가치요소를 하나의 모델로 평가하기 위하여 화학반응속도 추정식으로 널리 알려진 아레니우스식을 사용한 새로운 평가모델을 제시하였다. 한국의 소멸된 특허데이터를 활용하여 평가모델의 성능을 검증하였으며, 선행연구에서 특허평가모델로 사용되었던 SVM, Logistic reg., ANN 모델과 성능을 비교하였다. 결과적으로, 제안한 평가모델이 다른 모델 보다 정확도가 높았으며, 특허권자의 특성을 고려한 상대체감비용지수 반영 시 여러 평가모델에서 정확도가 상승하는 경향을 보였다. 또한, 특허의 예측수명등급과 특허의 실제수명과는 강한 상관관계가 있었다. 이러한 평가모델은 대량의 특허를 객관적으로 신속하게 평가할 수 있으며 특허의 유지여부에 대한 의사결정 혹은 기술거래나 평가에 활용할 수 있다. 특히, 평가목적에 따라 특허만을 평가하거나 사업화주체나 기술적 특성을 고려한 평가가 필요한 경우에 각각 사용될 수 있다.

새마을열차 환경소음 예측식 성능 비교에 관한 연구 (Put English Title Here)

  • 조준호;고효인;김재철
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2007년도 추계학술대회논문집
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    • pp.105-108
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    • 2007
  • Recently, due to the high interests for well being life, claims about noise ad vibration are increased very rapidly. Therefore more reliable and exact evaluation of noise impact has been required. Until now in Korea, only one prediction equation for the assessment of railway environmental noise was used. But that equation has many limits and weak points because of the update was not performed from 1993. So in this study, the performance of another equation proposed by authors was compared to the former. As a result, proposed prediction equation may be used to evaluate the impact of railway noise in the future.

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CFDS기법을 이용한 난류 유동장 해석 (Turbulent flow fields analysis using CFDS scheme)

  • 문성목;이정상;김종암;노오현;홍승규
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2001년도 춘계 학술대회논문집
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    • pp.51-59
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    • 2001
  • An evaluation of one zero-equation and two one-equation eddy viscosity-transport turbulence closure models as implemented CFDS(Characteristic Flux Difference Splitting ) code is presented herein. Comparisons of Baldwin-Lomax model as zero-equation and Baldwin-Barth and Spalart-Allmaras model as one-equation are presented for three test cases, first inlvolving the 3 dimensional supersonic flow at M=1.98 over tangent ogive cylinder, second involving the 2 dimensional transonic flow at M=0.79 over RAE 2822 airfoil, third involving the 3 dimensional transonic flow at M=0.84 over ONERA M6 wing. The numerical results of CFDS code will also examined through direct comparison with experimental data.

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유압 서보 제어계에서 밸브 선형화 방정식의 오차 평가 (Error Evaluation of the Linearized Equation of Servo Valve in Hydraulic Control Systems)

  • 김태형;이일영
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 추계학술대회논문집A
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    • pp.501-506
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    • 2001
  • In the procedure of the hydraulic control system analysis, a linearized approximate equation described by the first order term of Taylor's series has been widely used. Such a linearized equation is effective just near the operating point. In this study, the authors estimate computational errors in the process of applying the existing linearized equation stated above. For evaluating the computational accuracy in practical applications of the linearized equations, dynamic behaviors of hydraulic control systems are investigated through simulations with several kinds of representative hydraulic systems and the linearized equations suggested in this study.

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비부착 포스트텐션 정착구역 설계를 위한 파열력 산정 방법 (Bursting Force Equation for Design in Unbonded Post-Tensioned Anchorage Zone)

  • 노경민;이영학
    • 대한건축학회논문집:구조계
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    • 제34권12호
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    • pp.21-26
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    • 2018
  • For evaluating equations of bursting force in different codes, comparative study of the formulas was conducted. Because the equations does not consider variables such as shape of anchorages and duct, a relation between the bursting forces and the variables has to be analyzed. In this paper, the bursting forces equation was proposed by finite element analysis. As evaluation through comparison of the proposed equation with the previous ones and an experiment, it was figured out that bursting force computed by the proposed equation could be used for design of reinforcement in the anchorage zone.