• 제목/요약/키워드: multilinear regression analysis

검색결과 16건 처리시간 0.022초

Strength and toughness prediction of slurry infiltrated fibrous concrete using multilinear regression

  • Shelorkar, Ajay P.;Jadhao, Pradip D.
    • Advances in concrete construction
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    • 제13권 2호
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    • pp.123-132
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    • 2022
  • This paper aims to adapt Multilinear regression (MLR) to predict the strength and toughness of SIFCON containing various pozzolanic materials. Slurry Infiltrated Fibrous Concrete (SIFCON) is one of the most common terms used in concrete manufacturing, known for its benefits such as high ductility, toughness and high ultimate strength. Assessment of compressive strength (CS.), flexural strength (F.S.), splitting tensile strength (STS), dynamic elasticity modulus (DME) and impact energy (I.E.) using the experimental approach is too costly. It is time-consuming, and a slight error can lead to a repeat of the test and, to solve this, alternative methods are used to predict the strength and toughness properties of SIFCON. In the present study, the experimentally investigated SIFCON data about various mix proportions are used to predict the strength and toughness properties using regression analysis-multilinear regression (MLR) models. The input parameters used in regression models are cement, fibre, fly ash, Metakaolin, fine aggregate, blast furnace slag, bottom ash, water-cement ratio, and the strength and toughness properties of SIFCON at 28 days is the output parameter. The models are developed and validated using data obtained from the experimental investigation. The investigations were done on 36 SIFCON mixes, and specimens were cast and tested after 28 days of curing. The MLR model yields correlation between predicted and actual values of the compressive strength (C.S.), flexural strength, splitting tensile strength, dynamic modulus of elasticity and impact energy. R-squared values for the relationship between observed and predicted compressive strength are 0.9548, flexural strength 0.9058, split tensile strength 0.9047, dynamic modulus of elasticity 0.8611 for impact energy 0.8366. This examination shows that the MLR model can predict the strength and toughness properties of SIFCON.

Novel Hilbert spectrum-based seismic intensity parameters interrelated with structural damage

  • Tyrtaiou, Magdalini;Elenas, Anaxagoras
    • Earthquakes and Structures
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    • 제16권2호
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    • pp.197-208
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    • 2019
  • The objective of this study is to propose new seismic intensity parameters based on the Hilbert spectrum and to associate them with the seismic damage potential. In recent years the assessment of even more seismic features derived from the seismic acceleration time-histories was associated with the structural damage. For a better insight into the complex seismic acceleration time-history, Hilbert-Huang Transform (HHT) analysis is utilized for its processing, and the Hilbert spectrum is obtained. New proposed seismic intensity parameters based on the Hilbert spectrum are derived. The aim is to achieve a significant estimation of the seismic damage potential on structures from the proposed new intensity parameters confirmed by statistical methods. Park-Ang overall structural damage index is used to describe the postseismic damage status of structures. Thus, a set of recorded seismic accelerograms from all over the word is applied on a reinforced concrete frame structure, and the Park-Ang indices through nonlinear dynamic analysis are provided and considered subsequently as reference numerical values. Conventional seismic parameters, with well-known seismic structural damage interrelation, are evaluated for the same set of excitations. Statistical procedures, namely correlation study and multilinear regression analysis, are applied on the set of the conventional parameters and the set of proposed new parameters separately, to confirm their interrelation with the seismic structural damage. The regression models are used for the evaluation of the structural damage indices for every set of parameters, respectively. The predicted numerical values of the structural damage indices evaluated from the two sets of seismic intensity parameters are inter-compared with the reference values. The numerical results confirm the ability of the proposed Hilbert spectrum based new seismic intensity parameters to approximate the postseismic structural damage with a smaller Standard Error of Estimation than this accomplished of the conventional ones.

뇌 PET 영상 정량화 및 파라메터영상 구성을 위한 선형분석기법 (Linearized Methods for Quantitative Analysis and Parametric Mapping of Brain PET)

  • 김수진;이재성
    • Nuclear Medicine and Molecular Imaging
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    • 제41권2호
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    • pp.78-84
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    • 2007
  • Quantitative analysis of dynamic brain PET data using a tracer kinetic modeling has played important roles in the investigation of functional and molecular basis of various brain diseases. Parametric imaging of the kinetic parameters (voxel-wise representation of the estimated parameters) has several advantages over the conventional approaches using region of interest (ROI). Therefore, several strategies have been suggested to generate the parametric images with a minimal bias and variability in the parameter estimation. In this paper, we will review the several approaches for parametric imaging with linearized methods which include graphical analysis and mulilinear regression analysis.

Business Cycle and Occupational Accidents in Korea

  • Kim, Dong Koo;Park, Sunyoung
    • Safety and Health at Work
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    • 제11권3호
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    • pp.314-321
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    • 2020
  • Background: Occupational accidents occur for a variety of reasons, such as unsafe behaviors of workers and insufficient safety equipment at the workplace, but there are also various economic and social factors that can impact working conditions and working environment. This study analyzed the relationship between changes in economic factors and the occurrence of occupational accidents in Korea. Methods: Multilinear regression analysis was used as the analysis model. The general to specific method was also used, which consecutively removes statistically insignificant variables from a general model that includes dependent variables and lagged variables of dependent variables. Results: The frequency of occupational accidents was found to have a statistically significant relationship to economic indicators. The monthly number of cases of occupational injury and disease and fatal occupational injuries were found to be closely related to manufacturing capacity utilization, differences in the production index in the services sector, and commencements of building construction. The increase in equipment investment indicators was found to reduce fatal occupational injuries. Conclusion: The results of this study may be used to develop occupational accident trends or leading indicators, which in turn can be used by organizations that manage and monitor occupational accidents toward taking administrative action designed to reduce occupational accidents. The results also imply that short-term and mid- to long-term economic and social changes that can impact workers, workplaces and working conditions, and workplace organizations must be taken into account if more effective government policies are to be established and implemented toward further prevention of occupational accidents.

Leveraging artificial intelligence to assess explosive spalling in fire-exposed RC columns

  • Seitllari, A.;Naser, M.Z.
    • Computers and Concrete
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    • 제24권3호
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    • pp.271-282
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    • 2019
  • Concrete undergoes a series of thermo-based physio-chemical changes once exposed to elevated temperatures. Such changes adversely alter the composition of concrete and oftentimes lead to fire-induced explosive spalling. Spalling is a multidimensional, complex and most of all sophisticated phenomenon with the potential to cause significant damage to fire-exposed concrete structures. Despite past and recent research efforts, we continue to be short of a systematic methodology that is able of accurately assessing the tendency of concrete to spall under fire conditions. In order to bridge this knowledge gap, this study explores integrating novel artificial intelligence (AI) techniques; namely, artificial neural network (ANN), adaptive neuro-fuzzy inference system (ANFIS) and genetic algorithm (GA), together with traditional statistical analysis (multilinear regression (MLR)), to arrive at state-of-the-art procedures to predict occurrence of fire-induced spalling. Through a comprehensive datadriven examination of actual fire tests, this study demonstrates that AI techniques provide attractive tools capable of predicting fire-induced spalling phenomenon with high precision.

근적외분광분석법을 이용한 과산화수소의 농도 측정 (Determination of Hydrogen Peroxide Concentration by Portable Near-Infrared (NIR) System)

  • 임현량;우영아;장수현;김경미;김효진
    • 약학회지
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    • 제46권5호
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    • pp.324-330
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    • 2002
  • This experiment was carried out to determine non-destructively the hydrogen peroxide concentration of 3% antiseptic hydrogen peroxide solutions by portable near-infrared (NIR) system. Hydrogen peroxide standards were prepared ranging from 0 to 25.6 w/w% and the NIR spectra of hydrogen peroxide standard solutions were collected by using a quartz cell in 1 mm pathlength. We found the variation of absorbance band due to OH vibration of hydrogen peroxide depending on the concentration around 1400 nm in the second derivatives spectra. Partial least square regression (PLSR) and multilinear regression (MLR) were explored to develop a calibration model over the spectral range 1100-1720 nm. The model using PLSR was better than that using MLR. The calibration showed good results with a standard error of prediction (SEP) of 0.16%. In order to validate the developed calibration model, routine analyses were performed using commercial antiseptic hydrogen peroxide solutions. The hydrogen peroxide values from the NIR calibration model were compared with the values from a redox titration method. The NIR routine analyses results showed good correlation with those of the redox titration method. This study showed that the rapid and non-destructive determination of hydrogen peroxide in the antiseptic solution was successfully performed by portable NIR system without very harmful solvents.

태양활동극대기를 대비한 태양활동예보 (THE PREDICTION OF SOLAR ACTIVITY FOR SOLAR MAXIMUM)

  • 이진이;장세진;김연한;김갑성
    • 천문학논총
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    • 제14권2호
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    • pp.103-112
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    • 1999
  • We have investigated the solar activity variation with period shorter than 1000 days, through Fourier transformation of solar cycle 21 and 22 data. And real time predictions of the flare maximum intensity have been made by multilinear regression method to allow the use of multivariate vectors of sunspot groups or active region characteristics. In addition, we have examined the evolution of magnetic field and current density in active regions at times before and after flare occurrence, to check short term variability of solar activity. According to our results of calculation, solar activity changes with periods of 27.1, 28.0, 52.1, 156.3, 333.3 days for solar cycle 21 and of 26.5, 27.1, 28.9, 54.1, 154, 176.7, 384.6 days for solar cycle 22. Periodic components of about 27, 28, 53, 155 days are found simultaneously at all of two solar cycles. Finally, from our intensive analysis of solar activity data for three different terms of $1977\~1982,\; 1975\~1998,\;and\;1978\~1982$, we find out that our predictions coincide with observations at hit rate of $76\%,\;63\%$, 59 respectively.

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Assessment of compressive strength of high-performance concrete using soft computing approaches

  • Chukwuemeka Daniel;Jitendra Khatti;Kamaldeep Singh Grover
    • Computers and Concrete
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    • 제33권1호
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    • pp.55-75
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    • 2024
  • The present study introduces an optimum performance soft computing model for predicting the compressive strength of high-performance concrete (HPC) by comparing models based on conventional (kernel-based, covariance function-based, and tree-based), advanced machine (least square support vector machine-LSSVM and minimax probability machine regressor-MPMR), and deep (artificial neural network-ANN) learning approaches using a common database for the first time. A compressive strength database, having results of 1030 concrete samples, has been compiled from the literature and preprocessed. For the purpose of training, testing, and validation of soft computing models, 803, 101, and 101 data points have been selected arbitrarily from preprocessed data points, i.e., 1005. Thirteen performance metrics, including three new metrics, i.e., a20-index, index of agreement, and index of scatter, have been implemented for each model. The performance comparison reveals that the SVM (kernel-based), ET (tree-based), MPMR (advanced), and ANN (deep) models have achieved higher performance in predicting the compressive strength of HPC. From the overall analysis of performance, accuracy, Taylor plot, accuracy metric, regression error characteristics curve, Anderson-Darling, Wilcoxon, Uncertainty, and reliability, it has been observed that model CS4 based on the ensemble tree has been recognized as an optimum performance model with higher performance, i.e., a correlation coefficient of 0.9352, root mean square error of 5.76 MPa, and mean absolute error of 4.1069 MPa. The present study also reveals that multicollinearity affects the prediction accuracy of Gaussian process regression, decision tree, multilinear regression, and adaptive boosting regressor models, novel research in compressive strength prediction of HPC. The cosine sensitivity analysis reveals that the prediction of compressive strength of HPC is highly affected by cement content, fine aggregate, coarse aggregate, and water content.

근적외선 분광분석법을 이용한 음주측정기술 개발에 관한 연구 (Fundamental Investigation of Non-invasive Determination of Alcohol in Blood by Near Infrared Spectrophotometry)

  • 장수현;조창희;우영아;김효진;김영만;이강붕;김영운;박성우
    • 분석과학
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    • 제12권5호
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    • pp.375-381
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    • 1999
  • 본 연구는 기존에 사용되고 있는 음주측정기의 부정확성과 비위생적인 면을 개선하기 위한 비침습적인 알코올 측정기를 개발하기 위해 근적외선분광분석법을 적용하였다. 먼저 근적외선분광분석법으로 혈중 알코올을 측정하기 위한 전 단계로 순수한 알코올을 0.01~0.1%의 농도로 함유한 검체를 측정하였다. MLR(multiple linear regression)방법을 통한 통계적 처리에서 1360, 2256, 2012, 그리고 1358 nm의 네 파장을 선택했을 때 SEC(standard error of calibration)은 0.0039, multiple R은 0.99를 나타냈다. 혈중 알코올 시료 측정시 MLR을 적용했을 때 2266과 2326 nm 파장을 선택했을 경우 가장 유의성 있는 결과를 나타냈다. 또 다른 통계적 방법인 PLSR(partial least squares regression)의 경우 이차 미분 스펙트럼의 1100~1340, 1500~1796, 그리고 2064~2300 nm의 범위에서 4개의 factor를 사용했을 때 0.030의 SEP값을 나타냈다. 이로서 근적외선분광분석법을 이용하여 혈액 중의 알코올을 신속하게 분석할 수 있는 가능성을 제시하였다.

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R718-R744용 캐스케이드 냉동시스템의 최대 성능 예측 (Prediction on Maximum Performance of Cascade Refrigeration System Using R717 and R744)

  • 노건상;손창효
    • 한국산학기술학회논문지
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    • 제10권10호
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    • pp.2565-2571
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    • 2009
  • 본 논문은 시스템의 운전조건하에서 R717-R747용 이원냉동 사이클의 성능 분석에 대한 기초 설계자료를 제공하는 것이다. 본 논문에서 고려한 운전변수는 암모니아 고온사이클과 이산화탄소 저온사이클의 과냉각도, 과열도, 응축과 증발온도이다. 이원 냉동사이클의 성적계수는 과열도가 증가할수록 증가하는 반면, 과냉각도가 증가할수록 감소한다. 그리고, 이원 냉동사이클의 성적계수는 응축온도와 함께 증가하지만, 증발온도와는 반대로 감소한다. 따라서, 과열도, 과냉도, 응축과 증발온도는 본 시스템의 성적계수에 영향을 미치는 것을 알 수 있었고, 최대 성능계수와 최적의 증발온도에 대한 수학 방정식을 개발하기 위해 이러한 변수들을 포함시켜 다중 회귀분석을 통해 제안하였다.