• 제목/요약/키워드: estimating

검색결과 9,681건 처리시간 0.034초

운량을 고려한 국내 16개 지역의 일사량 예측방법 (A Study on the Solar Radiation Estimation of 16 Areas in Korea Using Cloud Cover)

  • 조덕기;강용혁
    • 한국태양에너지학회 논문집
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    • 제30권4호
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    • pp.15-21
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    • 2010
  • Radiation data are the best source of information for estimating average incident radiation. Lacking this or data from nearby locations of similar climate, it is possible to use empirical relation ships to estimate radiation from days of cloudiness. It is necessary to estimate the regression coefficients in order to predict the daily global radiation on a horizontal surface. There fore many different equations have proposed to evaluate them for certain areas. In this work a new correlation has been made to predict the solar radiation for 16 different areas over Korea by estimating the regression coefficients taking into account cloud cover. Particularly, the straight line regression model proposed shows reliable results for estimating the global radiation on a horizontal surface with monthly average deviation of -0.26 to +0.53% and each station annual average deviation of -1.61 to +1.7% from measured values.

개구부가 있는 무량판 슬래브의 뚫림전단에 대한 위험단면 결손 산정 (Estimating Ineffective Part of Critical Section for Punching Shear Strength of Flat Slabs with Openings)

  • 하태훈;오보환
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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    • pp.370-373
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    • 2006
  • According to current design provisions for shear strength of reinforced concrete slabs, critical slab sections around columns should be modified in the presence of openings in slabs to consider the effect of openings on the shear strength of slabs. Although the method of estimating the ineffective part of critical section due to openings are explained in codes, the real math for calculating it is somewhat complex and cumbersome. This paper classifies different cases of the location and geometry of columns and openings, respectively, and derives corresponding equations for estimating ineffective part of critical section for each case.

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원전 건설공사 실적공사비 단가 제도 도입을 위한 연구 (A study on application method of "Result unit cost" to Nuclear Power Plant (NPP) construction cost estimating)

  • 박원섭;장경수
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2014년도 춘계 학술논문 발표대회
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    • pp.46-47
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    • 2014
  • Recently, BAI(Board of Audit and Inspection of Korea) has recommended that "Result unit cost" of Korean government apply to national power plant construction project when plant owner corporations estimate budget price for tender. but nuclear industry have difficulties with this suggestion. the purpose of this study is to review the "Result unit cost" and problem with application of NPP construction cost estimating. And proposed the direction of application of "Result unit cost" to NPP construction cost estimating.

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Estimating small area proportions with kernel logistic regressions models

  • Shim, Jooyong;Hwang, Changha
    • Journal of the Korean Data and Information Science Society
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    • 제25권4호
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    • pp.941-949
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    • 2014
  • Unit level logistic regression model with mixed effects has been used for estimating small area proportions, which treats the spatial effects as random effects and assumes linearity between the logistic link and the covariates. However, when the functional form of the relationship between the logistic link and the covariates is not linear, it may lead to biased estimators of the small area proportions. In this paper, we relax the linearity assumption and propose two types of kernel-based logistic regression models for estimating small area proportions. We also demonstrate the efficiency of our propose models using simulated data and real data.

인구구조 상이점에 의해 본 지역별 주택수요예측에 관한 연구 (A Study on the Estimation of the Housing Demand in Different Local Areas in Relation with the Differents of Population Structure)

  • 배정인
    • 한국주거학회논문집
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    • 제6권2호
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    • pp.33-42
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    • 1995
  • At the moment the housing demand needs estimated at the level of provinces and big cities. But at the level of small cities and smaller administrative unit like Goon, it is not, for lack of appropriate estimating method. Therefore it is very much required to develope appropriate estimating method at such levels. This study is an attempt to apply to some local areas the estimating method developed by Professor Miyqke of Japan as is suggested in his article. "How to Estimate the Housing Demand in Relation with the Different of Poulation Structure." The result shows that the applied local areas showed repective characteristics distinguished from one another in the pattern of housing demand, to prove the approprateness of the method when applied to the areas at the level of small cities and Goons.

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케이블 고장 진단을 위한 선형 칼만필터 기반 반사파 계측법 연구 (Fault Diagnosis for Cable Using Reflectometry Based on Linear Kalman Filtering)

  • 이춘구;윤태성;박진배
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2009년도 정보 및 제어 심포지움 논문집
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    • pp.19-21
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    • 2009
  • The reflectometry for locating the fault at a cable is the same as a problem estimating the time delay between the incident and the reflected signals. In this paper, we propose a method for estimating the time delay between the two signals. The proposed method is based on the modeling of the Gaussian enveloped linear chirp signal in the Gaussian noise environment. The phase and the instantaneous frequency of the received signal are estimated by linear Kalman filtering. From the estimated instantaneous frequency, we can measure the time interval between the center frequencies of the incident and the reflected signals. The time interval is the same as the time delay between the incident and the reflected signals. In a simulation assuming that the cable has open fault at the end of the cable, the proposed method showed a good result in estimating the time delay.

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A practical neuro-fuzzy model for estimating modulus of elasticity of concrete

  • Bedirhanoglu, Idris
    • Structural Engineering and Mechanics
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    • 제51권2호
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    • pp.249-265
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    • 2014
  • The mechanical characteristics of materials are very essential in structural analysis for the accuracy of structural calculations. The estimation modulus of elasticity of concrete ($E_c$), one of the most important mechanical characteristics, is a very complex area in terms of analytical models. Many attempts have been made to model the modulus of elasticity through the use of experimental data. In this study, the neuro-fuzzy (NF) technique was investigated in estimating modulus of elasticity of concrete and a new simple NF model by implementing a different NF system approach was proposed. A large experimental database was used during the development stage. Then, NF model results were compared with various experimental data and results from several models available in related research literature. Several statistic measuring parameters were used to evaluate the performance of the NF model comparing to other models. Consequently, it has been observed that NF technique can be successfully used in estimating modulus of elasticity of concrete. It was also discovered that NF model results correlated strongly with experimental data and indicated more reliable outcomes in comparison to the other models.

경제성공학의 한계에 관한 고찰 (A Study on Limiting Factor of Capital Assets Investment Calculation)

  • 김성집
    • 산업경영시스템학회지
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    • 제2권2호
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    • pp.5-10
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    • 1979
  • For investment calculation of capital assets, it is desirable to grasp the limiting factors of its calculation. The limiting factors can be listed as follows; $\circled1$ difficulty in estimating the service life of capital assets. $\circled2$ difficulty in estimating the receipts, and operating and maintenance expenses of the project. $\circled3$ difficulty in determining common Minimum Attractive Rate of Return. $\circled4$ difficulty in estimating the salvage value of the assets. $\circled5$ some limiting factors on present worth calculation of the projects. $\circled6$ Some limiting factors on payout period method of the economic calculation.

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EVALUATION OF TECHNIQUES FOR ESTIMATING MILK PRODUCTION BY SOWS 4. A COMPARISON OF TWO WEIGH-SUCKLE-WEIGH TECHNIQUES (OFFSPRING AND MATERNAL) FOR ESTIMATING MILK PRODUCTION

  • Prawirodigdo, S.;King, R.H.;Hughes, P.E.;Dunkin, A.C.
    • Asian-Australasian Journal of Animal Sciences
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    • 제4권2호
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    • pp.165-168
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    • 1991
  • The maternal weigh-suckle-weigh (WSW) method for estimating milk production of sows was further evaluated by comparing this to the traditional WSW method. Twenty one estimates of hourly milk production were obtained by both methods. Total hourly milk production between the two methods was not significantly different (292.4 vs 303.3 g/h, p > 0.05). Hourly milk production determined by the maternal WSW method was highly correlated with hourly milk production estimates using the traditional WSW method ($R_2$ = 0.94, p < 0.001). When corrections for metabolic and salivary losses were made, the milk production figures for the maternal WSW method were approximately 27% less than those estimated by the traditional WSW method.

배전계통 고장위치 검출방법에 관한 연구 (A Study on the Estimating Locations of Faults on Distribution Power Systems)

  • 김미영;오용택;노대석
    • 대한전기학회논문지:전력기술부문A
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    • 제53권12호
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    • pp.670-677
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    • 2004
  • The Conventional approach for estimating the locations of transmission line shunt faults has been to measure the apparent impedance to the fault from a line terminal and to convert the reactive component of the impedance to line length. But, these methods do not adequately address the problems associated with the fault location on distribution systems. This thesis presents a technique that estimates the location of shunt fault on a radial distribution system that has several single and multiphase laterals. Tapped loads and non-homogenity of the distribution system are take into account. The developed technique, which can handle shunt faults was tested to evaluate its suitability. Results from computer simulation of faults on a model of a 25KV distribution lines like real system are presented. The results approved that the proposed technique works well for estimating the locations of the distribution line shunt faults.