• Title/Summary/Keyword: prediction equations

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Analysis of the Limitations of the Existing Subsidence Prediction Method Based on the Subsidence Measurement Data and Suggestions for Improvement Method Through Weighted Nonlinear Regression Analysis (기존 계측 기반 침하 예측 이론식 한계점 도출 및 가중 비선형 회귀분석을 통한 침하 예측 개선방안 제시)

  • Kwak, Tae-Young;Hong, Seongho;Lee, Ju-Hyung;Woo, Sang-Inn
    • Journal of the Korean Geotechnical Society
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    • v.38 no.12
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    • pp.103-112
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    • 2022
  • The existing subsidence prediction method based on the measurement data were confirmed in this study through literature research. It was confirmed that the hyperbolic method and the Asaoka method showed high accuracy, while the other prediction methods showed significantly low accuracy. Based on the analysis results, the limitations of the existing prediction equations were derived, and the improvement method of the settlement prediction equations was suggested. In this study, a weighted nonlinear regression analysis method that gives higher weight to the later data was proposed to improve the existing hyperbolic method.

Ground-Motion Prediction Equations based on refined data for dynamic time-history analysis

  • Moghaddam, Salar Arian;Ghafory-Ashtiany, Mohsen;Soghrat, Mohammadreza
    • Earthquakes and Structures
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    • v.11 no.5
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    • pp.779-807
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    • 2016
  • Ground Motion Prediction Equations (GMPEs) are essential tools in seismic hazard analysis. With the introduction of probabilistic approaches for the estimation of seismic response of structures, also known as, performance based earthquake engineering framework; new tasks are defined for response spectrum such as the reference criterion for effective structure-specific selection of ground motions for nonlinear time history analysis. One of the recent efforts to introduce a high quality databank of ground motions besides the corresponding selection scheme based on the broadband spectral consistency is the development of SIMBAD (Selected Input Motions for displacement-Based Assessment and Design), which is designed to improve the reliability of spectral values at all natural periods by removing noise with modern proposed approaches. In this paper, a new global GMPE is proposed by using selected ground motions from SIMBAD to improve the reliability of computed spectral shape indicators. To determine regression coefficients, 204 pairs of horizontal components from 35 earthquakes with magnitude ranging from Mw 5 to Mw 7.1 and epicentral distances lower than 40 km selected from SIMBAD are used. The proposed equation is compared with similar models both qualitatively and quantitatively. After the verification of model by several goodness-of-fit measures, the epsilon values as the spectral shape indicator are computed and the validity of available prediction equations for correlation of the pairs of epsilon values is examined. General consistency between predictions by new model and others, especially, in short periods is confirmed, while, at longer periods, there are meaningful differences between normalized residuals and correlation coefficients between pairs of them estimated by new model and those are computed by other empirical equations. A simple collapse assessment example indicate possible improvement in the correlation between collapse capacity and spectral shape indicators (${\varepsilon}$) up to 20% by selection of a more applicable GMPE for calculation of ${\varepsilon}$.

Genetic Studies and Development of Prediction Equations in Jersey${\times}$Sahiwal and Holstein-Friesian${\times}$Sahiwal Half Breds

  • Singh, P.K.;Kumar, Dhirendra;Varma, S.K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.2
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    • pp.179-184
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    • 2005
  • First lactation records (174) of Jersey${\times}$Sahiwal and Holstein Friesian${\times}$Sahiwal half breds under 9 sires maintained at Chandra Shekher Azad University of Agriculture and Technology, Kanpur, Uttar Pradesh, India from 1975-1983, were used to estimate the genetic parameters and to predict herd life milk yield and average milk yield per day of herd life from first lactation traits. The traits included were: age at first calving, first service period, first lactation period, first calving interval, first lactation milk yield, milk yield per day of first calving interval, herd life milk yield, herd life and average milk yield per day of herd life. Most of the production and reproduction traits were found to have positive and significant correlations between them on genetic as well as phenotypic scales. Total twelve regression equations were fitted. The prediction equation of herd life milk yield in both the genetic groups showed linear relationship with AFC, FSP, FLP, FLMY and MY/DCI and was apparent and significant. Similarly, polynomials for milk yield per day of herd life for J${\times}$S and HF${\times}$S half breds also showed linear trend, which was found highly significant. The highest and lowest $R^2$ values were found for FCI and AFC, respectively.

Computation of Dynamic Damping Coefficients for Projectiles using Steady Motions (정상 운동을 이용한 발사체의 동적 감쇠계수 계산)

  • Park,Su-Hyeong;Gwon,Jang-Hyeok
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.31 no.8
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    • pp.19-26
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    • 2003
  • A steady prediction method of dynamic stability derivatives is presented in the unified framework of the unsteady Euler equations. New approach does not require any modification of the governing equations except addition of non-inertial force terms. The present methods are applied to compute the pitch-damping coefficients using the lunar coning and the lunar helical motions in the Cartesian coordinate frame. The results for the ANSR and the Basic Finner are in good agreement with the PNS data, range data, and the results using the unsteady prediction method. The results show that the steady approach using the unified governing equations in the Cartesian coordinate frame can be successfully applied to predict the pitch-damping coefficients.

Incorporating ground motion effects into Sasaki and Tamura prediction equations of liquefaction-induced uplift of underground structures

  • Chou, Jui-Ching;Lin, Der-Guey
    • Geomechanics and Engineering
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    • v.22 no.1
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    • pp.25-33
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    • 2020
  • In metropolitan areas, the quantity and density of the underground structure increase rapidly in recent years. Even though most damage incidents of the underground structure were minor, there were still few incidents causing a great loss in lives and economy. Therefore, the safety evaluation of the underground structure becomes an important issue in the disaster prevention plan. Liquefaction induced uplift is one important factor damaging the underground structure. In order to perform a preliminary evaluation on the safety of the underground structure, simplified prediction equations were introduced to provide a first order estimation of the liquefaction induced uplift. From previous studies, the input motion is a major factor affecting the magnitude of the uplift. However, effects of the input motion were not studied and included in these equations in an appropriate and rational manner. In this article, a numerical simulation approach (FLAC program with UBCSAND model) is adopted to study effects of the input motion on the uplift. Numerical results show that the uplift and the Arias Intensity (Ia) are closely related. A simple modification procedure to include the input motion effects in the Sasaki and Tamura prediction equation is proposed in this article for engineering practices.

A PREDICTION OF BODY WATER COMPARTMENTS OF GROWING CATTLE IN VIVO

  • Sekine, J.;Fujita, K.;Asahida, Y.
    • Asian-Australasian Journal of Animal Sciences
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    • v.5 no.1
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    • pp.7-11
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    • 1992
  • Body water compartments in vivo were determined in Holstein cattle with age ranging from 5 to 521 days to obtain an equation to estimate volumes of body water. Live weight ranged from 47 to 480 kg. Compartments were determined as antipyrine space for total body water (TBW), thiocyanate space for extracellular water (ECW) and Evans blue dye space for plasma water (PW). Body water compartments expressed as a percentage of live weight decreased as age in days increased and significantly correlated with age in days. Regression analyses revealed that prediction equations had low accuracy. Regression equations of body water compartments on live weight (WT, kg) were useful for the prediction of body fluid with a high accuracy. Live weight significantly regressed on age in days (Day), which was inferred to be utilized for estimation of standardized live weight in case animals were emaciated by certain causes such as severe diarrhea or dehydration. In conclusion, following equations were presented to estimate body water compartments of cattle in vivo : TBW in liters = $0.556({\pm}0.007)WT+10$, r = 0.993, $SE{\pm}0.7$ ECW in liters = $0.321({\pm}0.008)WT+10$, r = 0.978, $SE{\pm}0.8$ PW in liters = $0.0502({\pm}0.0012)WT+1.6$, r = 0.0983, $SE{\pm}0.1$ WT (kg) = $0.772({\pm}0.018)Day+24$, r = 0.982, $SE{\pm}2.3$.

Prediction of Effect Zone for Marine Organisms Using Distance Attenuation Equations for Oceanic Noise (수중소음 거리감쇠 특성식을 이용한 해양생물 피해영향범위 예측)

  • Ha, Jeong-Min;Lee, Jong-Myeong;Lee, Jeong-Hoon;Gu, Dong-Sik;Choi, Byeong-Keun
    • Journal of Ocean Engineering and Technology
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    • v.26 no.2
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    • pp.14-19
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    • 2012
  • There are insufficient data to consider the effect zone for the marine life of coastal fisheries, because no standard has been defined for the sound level of marine life. In this study, equations for distance attenuation were used to determine the effect zone for oceanic noises. A reference noise level was divided into 4 parts to consider the characteristics of the fishes, and the effect zone of each reference noise level was determined. To increase the reliability of the effect scope, approximately 100 repetitions of blasting work split into several parts by the boring depth, the sound level of the source caused by an increase in weight, and the effect zone were calculated using the prediction equation. According to the prediction, the maximum distance of the effect zone was 4.92 km.

Nonlinear regression methods and genetic algorithms for estimation of compression index of clays using toughness limit

  • Satoru Shimobe;Eyyub Karakan;Alper Sezer
    • Geomechanics and Engineering
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    • v.37 no.4
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    • pp.371-382
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    • 2024
  • Measurement or prediction of compression index (Cc) of soils is essential for assessment of total and differential settlement of structures. It is a well-known fact that this parameter is controlled by several index identifiers of soil including initial void ratio, Atterberg limits, overconsolidation ratio, specific gravity, etc. Many studies in the past proposed relationships for prediction of Cc based on different index properties. Therefore, this study aims to present a comparison of previously proposed equations for estimation of Cc. Data from literature was compiled, and a total of 90 and 623 test results on remolded and undisturbed specimens were used to question the validity of previously proposed equations. Nevertheless, the modeling ability of 7 and 12 equations for estimation of Cc of remolded and undisturbed soils were questioned by use of compiled data. Moreover, new empirical relationships based on initial void ratio and toughness limit for prediction of Cc was proposed by use of nonlinear multivariable regression and evolutionary based regression analyses. The results are promising-the performances of models established are quite acceptable, which are verified by statistical analyses.

Strength Prediction Equations of High Strength Concrete by Schmidt Hammer Test (슈미트 해머 시험법에 의한 고강도 콘크리트의 강도 추정식)

  • Park Song Chul;Yoo Jae Eun;Kim Min Su;Kwon Young Wung
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.11a
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    • pp.615-618
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    • 2005
  • This study concerns the equation of high strength concrete by schmidt hammer test. There are not only few prediction strength equations of concrete by schmidt hammer test, but also many problems to apply them because of time, cost, easiness, structural damage, reliability and so on. For this study, there performed a series of schmidt hammer test with in existing 1,095days' concrete structures and proposed equations as follows ; Linear: ${\Large f}_{ck}=-45.35+2.44R(r^2=72.7\%)$ Quadratic: ${\Large f}_{ck}=-502.08+24.0R-0.25R^2(r^2=82.4\%)$ here, $f_{ck}$ : Estimated compressive strength of concrete by MPa, R : Rebound index of concrete

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Experimental Study on the Creep Properties of High Strength Concrete (고강도 콘크리트의 크리프 특성에 관한 실험적 연구)

  • Joung, Won-Seoup;Park, Dong-Su;Kwon, Ki-Joo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2010.05a
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    • pp.337-338
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    • 2010
  • In this study, the test results on creep properties of high strength concrete are shown compared with various prediction equations about creep. So in order to investigate the creep properties of high strength concrete, the application possibility of prediction equations about creep is studied compared with the equations in ACI-209 and CEB/FIP-90 for concrete produced using Portland cement.

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