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THE ANALYSIS OF SELECTED PARAMETERS OF BLAST FURNACE OPERATION

METALURGIJA 2019年第3-4期58卷 287-290页

作者： Kardas, E. Prusak, R. Czestochowa Tech Univ Fac Prod Engn & Mat Technol Czestochowa Poland

The paper presents results of the analysis of selected parameters of blast furnace operation and the influence of various factors on them. The study was carried out in cooperation with a Blast-Furnace Department of a Polish steelworks and was based on the results coming from this Department. The analysis covers the period of one calendar year.

关键词： blast furnace pig iron effectiveness productions linear regression method

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Research on Municipal Financing Based on linear regression to Promote Urban Competitiveness

Research on Municipal Financing Based on Linear Regression t...

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International Conference on Economic Management and Model Engineering (ICEMME)

作者： Li, Bahao Jiujiang Univ Sch Econ & Management Jiujiang Peoples R China

ISBN: (纸本)9781728155883

With the development of economic globalization and regional integration, the development of countries, regions, and cities is continuously accelerating. At the same time, it also means that competitions between countries, regions and cities are becoming increasingly fierce. Today, improving the competitiveness of cities has become the main goal of a country. The economic competition between countries is now specifically represented by city-level competition. If a country does not have a city that can be listed as a first-class economic zone in the world, then there is no way for the country to lead in the economic wave. Urban competitiveness determines the resources, capabilities and rights that cities can get, and the improvement of urban competitiveness cannot be achieved without the help of municipal financing. Municipal financing is in a severe situation now. If we want to achieve the sustainable development goal of the city, we need insight capital as a necessary input basis, that is, municipal financing of the city is an important influencing factor to guarantee the constant improvement of urban competitiveness and realize city's sustainable development. At the same time, the local government is the government entity that closely manages the city. The municipal government plays a decisive role in public services, education, business environment, and affecting the quality of local life. However, today's municipal financing has many shortcomings in terms of resources, capabilities, and rights, which limit local empiricism to provide cities with the development momentum they need. Therefore, improving the financial status of municipalities and promoting the development of municipal financing are vital to urban development. This article will analyze the impact of municipal financing on promoting urban competitiveness, and explore the relationship between municipal financing and urban competitiveness by establishing a multiple linear regression model.

关键词： linear regression method municipal financing urban competitiveness improvement economic model

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Precipitation variability and its trend detection for monitoring of drought hazard in northern mountainous region of Pakistan

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ARABIAN JOURNAL OF GEOSCIENCES 2020年第15期13卷 698-698页

作者： Khan, Imran Waqas, Tahir Samiullah Ullah, Safi Univ Peshawar Ctr Disaster Preparedness & Management CDPM Peshawar Pakistan Univ Peshawar Natl Ctr Excellence Geol Peshawar Pakistan Univ Peshawar Dept Geog Peshawar Pakistan Nanjing Univ Informat Sci & Technol NUIST Sch Atmospher Sci Nanjing 210044 Peoples R China

The Standardized Precipitation Index (SPI) is a powerful tool, requiring only precipitation data for calculating the intensity, duration, magnitude, severity and frequency of drought. Moreover, it provides helpful coverage of drought impacts on multi time scales. In this study, the SPI technique was applied to the dataset of 30 years (1986-2015) to detect drought condition in Northern Pakistan, which is a frequent drought-hit area. The coefficient of variability (CV) was used to analyze precipitation trend, while linear regression model was adopted to detect trend. The detected precipitation variability was spatially interpolated by applying the Inverse Distance Weighted (IDW) technique. It is evident from the analysis that there is great variability in precipitation pattern and trend in the study area. During the winter season, a positive trend in the precipitation variability was detected in the Himalaya and Karakorum region. In the Hindukush region, only Pattan weather station has observed a positive variability trend. In contrast to winter variability, pre-monsoon season has observed an increased variability in the Hindukush region, while the Karakorum and Himalayas regions observed a negative trend. The monsoon season has observed a decreased variation in precipitation throughout the study area except for Pattan. In post-monsoon, Skardu weather station of Himalayas, Gupis and Bunji of Karakorum region and Pattan of Hindukush region have witnessed increased precipitation variability. The meteorological stations of Karakoram and Himalaya have noticed a negative trend of precipitation variability, while in the Hindukush region, all the meteorological stations have witnessed a positive trend of variability except Saidu Sharif and Dir stations. The results of SPI also indicated a drought condition in the study area. Similarly, the SPI results of all return periods have shown a significant drought condition in the Himalayas followed by-in terms of frequency and magni

关键词： SPI linear regression method Drought hazard MRP Pakistan

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Accurate estimation of soil shear strength parameters

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Journal of Central South University 2019年第4期26卷 1000-1010页

作者： CHEN Li-hong LI Xu XU Yao CHEN Zu-yu DENG Gang Department of Civil Engineering Beijing Jiaotong University China Institute of Water Resources and Hydropower Research

The cost and safety of geotechnical engineering are highly depending on the accuracy of soil shear strength *** are three methods often used to estimate soil shear strength parameters,i.e.,moment method,3-sigma rule and linear regression *** this study,the accuracy of these three methods is *** linear regression method(LRM)can only offer the mean of shear strength *** engineers misuse the standard error of shear strength indexes as the standard *** misuse may highly underestimate the uncertainty and induce high risk to the geotechnical design.A modified LRM is proposed to determine both the mean and variance of shear strength *** moment method,three-sigma rule and LRM are used to analyze the tri-axial test data in Xiaolangdi Hydraulic Project and three numerical shear strength *** results demonstrate that:1)The modified LRM can offer the most accurate estimation to shear strength parameters;2)A dimensionless formula is much preferred in LRM rather than a dimensional *** stress ratio formula is much better than stress relation in the shear strength parameter *** proposed method is applicable to shear strength parameter analysis for tri-axial test data,direct shear test and the un-drained shear strength test of stratified clay.

关键词： linear regression method shear strength index tri-axial test reliability analysis data analysis uncertainty

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Data-driven horticultural crop model for optimal fertigation management -a methodology description

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IFAC-PapersOnLine 2018年第17期51卷 472-476页

作者： Dong, Qiaoxue Sun, Qingnan Hu, Yajing Xu, Yun Qu, Mei Ministry of Agriculture China Agricultural University Beijing100083 China College of horticulture China Agricultural university Beijing Key Laboratory of Growth and Development Regulation for protected Vegetable Crops Beijing100193 China

Fertigation has been proved a good agricultural practice for greenhouse crop production with respect to the efficiency of water and fertilizer use. but the frequency of irrigation and N fertilization, as well as their quantity, has important effects on crop's high yield and quality. To further save the irrigation water and N fertilizer application meanwhile ensuring the maximum productivity, the rational fertigation management is indispensable. Crop growth model provide a useful tool to help determine optimal management practices. This paper illustrates the basic methodological approaches and structure for optimal fertigation management by using a data-driven model. The data-driven model is derived from the given data and nonlinear regression method is applied to set up the model. The model parameters are identified by ordinary least square method. After the model's evaluation, a osculating value method is proposed to optimize the fertigation management combined with the data-driven model. The modeling and optimization algorithms, as well as the input and output interface, are implemented in standard c language, which is easy to be integrated into smart device like fertigation machine, to enhance the intelligence of device or controller. The experimental data from four crops including tomato, cucumber, sweet pepper, and strawberry were collected to assess the performance index of above methodology approaches, the preliminary results show that the system framework and the methodology adopted can be used to help farmer-level fertigation management as an alternative tool. © 2018

关键词： Information management Agricultural robots C (programming language) Crops Cultivation Identification (control systems) Irrigation Least squares approximations Modeling languages Nitrogen fertilizers Optimization regression analysis Structural optimization Data driven model Fertigations Good agricultural practices Greenhouse crop production Modeling and optimization Non linear regression method Ordinary least square methods Sustainable production

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EVALUATION OF A regression PREDICTION MODEL FOR SURFACE ROUGHNESS OF WOOD-POLYETHYLENE COMPOSITE (WPC)

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SURFACE REVIEW AND LETTERS 2017年第Sup2期24卷 1850033-1850033页

作者： Shi, Wenyong Ma, Yan Yang, Chunmei Jiang, Bin Li, Zhe Harbin Univ Sci & Technol Div Grad Harbin 150080 Heilongjiang Peoples R China Harbin Engn Univ Minist Educ Key Lab Superlight Mat & Surface Technol Harbin 150001 Heilongjiang Peoples R China Northeast Forestry Univ Forest Woodworking Machinery Res & Dev Ctr Harbin 150040 Heilongjiang Peoples R China Harbin Univ Sci & Technol Sch Mech Engn Harbin 150080 Heilongjiang Peoples R China

Milling processing is an important way to obtain wood-polyethylene composite (WPC) end products. In order to improve the processing efficiency and surface quality of WPC and meet the practical application requirements, this paper focussed on morphology and roughness of the WPC-milled surface and studied surface quality changes under different cutting parameters and milling methods through multi-parameters milling experiments. The milling surface morphology and roughness of WPC were analyzed and measured during cut-in, cutting and cut-out sections. It also revealed the affect rule of different cutting parameters and milling methods on milled surface morphology and roughness. The results show that the milling surface roughness of WPC products with wood powder content of 70% is significantly larger than the one whose wood powder content is 60%, and defects such as holes are also relatively more. Finally, a surface roughness prediction model was established based on the mathematical regression method and its multi-factor simulation was carried out. A comparative analysis of predictive and experimental values was performed to verify the reliability of the model. It could also provide theoretical guidance and technical guarantee for high processing quality of WPC milling and cutting.

关键词： Wood-polyethylene composite (WPC) milling surface roughness linear regression method

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Variability of Spatially Grid-Distributed Precipitation over the Huaihe River Basin in China

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WATER 2017年第7期9卷 489-489页

作者： Yu, Zhi-Lei Yan, Deng-Hua Ni, Guang-Heng Do, Pierre Yan, Deng-Ming Cai, Si-Yu Qin, Tian-Ling Weng, Bai-Sha Yang, Mei-Jian Tsinghua Univ THU Dept Hydraul Engn Beijing 100084 Peoples R China China Inst Water Resources & Hydropower Res IWHR State Key Lab Simulat & Regulat Water Cycle River Beijing 100038 Peoples R China IWHR Dept Water Resources Beijing 100038 Peoples R China Donghua Univ Coll Environm Sci & Engn Shanghai 201620 Peoples R China Univ Connecticut Dept Civil & Environm Engn Storrs CT 06269 USA

This study investigates spatial characteristics of annual and decadal precipitation in the Huaihe River basin. Daily precipitation data, obtained from meteorological gauges, are analyzed for a 51-year period, from 1961 to 2011. Precipitation is analyzed in grids (5 km(2)) with respect to temporal variability. The spatial distribution and intensity of annual rainfall (mm/10 year), determined by the linear regression method, reveals a slight increase of 3 mm/10 year over the basin. However, the trend did not present a significant change at 95% significance level in the most of basin. Precipitation is mostly increasing for each ten-year periods during the total 51 years. The annual precipitation randomicity was calculated from the non-uniform coefficient Cv (coefficient of variation) test and showed a significant non-uniform spatial distribution, indicating that randomicity of annual rainfall was the moderate variability. The Pettitt test determined that the abrupt change points occurred mainly in 1965, 1975 and 2002. Wavelet analysis showed that cyclic variations appeared almost every 5 to 10 years, accounting for 36% of the basin area. Meanwhile, these cycles tended to be delimited by the abrupt change points. This study aims to provide insights for water resources management, mitigation of climate change effects and water supply in the Huaihe River basin and surrounding watersheds.

关键词： wtershed hydrology grid-distributed precipitation Huaihe River basin linear regression method coefficient of variation Pettitt test wavelet analysis

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Computational aerodynamic modeling for flight dynamics simulation of ram-air parachutes

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AEROSPACE SCIENCE AND TECHNOLOGY 2016年 54卷 286-301页

作者： Ghoreyshi, Mehdi Bergeron, Keith Jirasek, Adam Seidel, Juergen Lofthouse, Andrew J. Cummings, Russell M. US Air Force Acad High Performance Comp Res Ctr Colorado Springs CO 80840 USA US Army Natick Res Ctr Dev & Engn Natick MA 01760 USA

This work presents a step toward bridging the gap between flight dynamics simulation of ram-air parachutes and high-fidelity computational fluid dynamics. Today's parachute design codes mainly rely on the empirical or semi-empirical methods generated from wind tunnel experiments and drop tests. The outcome of this study will hopefully help to reduce the cost of experiments and drop testing in the design of future canopies and to better understand the aerodynamic characteristics of these geometries. In this work, the parachute geometries were modeled as rigid rectangular wings with an aspect ratio of two and zero anhedral angle. The wings have seven opening cells and the trailing edge is deflected or not deflected. To validate computational methods, the aerodynamic predictions of similar wings, but with closed and round inlets, are compared with experimental data available from the Subsonic Wind Tunnel at United States Air Force Academy. Total lift and drag force coefficients were measured at a Reynolds number of 1.4 million. The results show that computational predictions of fine (closed-inlet) grids match the experimental data very well up to the stall angle. Both experiments and simulations show that closed wings have sharp stalling characteristics. The aerodynamics of closed wings up to stall can be approximated by linear functions and their derivatives. The closed wings show a negative static stability with respect to changes in the angle of attack. The open wings, on other hand, have positive static stability in the longitudinal and lateral directions. The open wings exhibit highly nonlinear unsteady aerodynamic characteristics;they also stall earlier and have higher drag values than the closed wings. The aerodynamic derivatives of open and closed wings were estimated using a linear regression method and training data simulated in small-amplitude oscillations in pitch, yaw, and roll directions. While the open wings have large oscillations in aerodynamic coeffic

关键词： Ram-air parachutes linear regression method Dynamic derivatives

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Both-branch amphiphilic polymer oil displacing system: Molecular weight, surfactant interactions and enhanced oil recovery performance

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COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS 2016年 509卷 440-448页

作者： Ji, Yanfeng Wang, Duanping Cao, Xulong Guo, Lanlei Zhu, Yangwen Sinopec Shengli Oilfield Co Ltd Explorat & Dev Res Inst Dongying 257000 Peoples R China

Hydrophobically modified polyacrylamidepolymers were synthesized by an aqueous micellar copolymerization, the N-benzyl-N-n-hexadecyl acrylamide being used as hydrophobic comonomer. The effect of the molecular weight (MW) and surfactant interactions on the rheological properties and oil-water interfacial activity were studied. The results indicate that increasing MW, the critical aggregation concentration of amphiphilic polymer will be decreased, and the network structural strength increased, which was measured by fluorescent probes, DLS and electron microscope. Mixing with the surfactant, sodium dodecyl sulfate (SDS), the solution viscosity increased at first and decreased later on with increasing the ratio of SDS concentration, and the dynamic interfacial tension between oil and water can be reduced by two orders of magnitude compared to the polymer solution only. The result of enhance oil recovery performance of the polymer/surfactant compound system is that it can significantly reduce the residual oil saturation due to the synergistic effect of the increasing viscosity and surface activity. The overall recovery efficiency was raised by 10-25% OOIP compared to the baseline polymers. (C) 2016 Elsevier B.V. All rights reserved.

关键词： Both-branch amphiphilic polymer Polymer/surfactant compound system Aggregation behavior linear regression method Dynamic interfacial tension Enhanced oil recovery

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Energy estimation models for video decoders: reconfigurable video coding-CAL case-study

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IET COMPUTERS AND DIGITAL TECHNIQUES 2015年第1期9卷 3-15页

作者： Ren, Rong Juarez, Eduardo Sanz, Cesar Raulet, Mickael Pescador, Fernando Univ Politecn Madrid Res Ctr Software Technol & Multimedia Syst CITSEM ES-28031 Madrid Spain CNRS UMR 6164 IETR INSA F-35043 Rennes France

In this study, a platform-independent energy estimation methodology is proposed to estimate the energy consumption of reconfigurable video coding (RVC)-CAL video codec specifications. This methodology is based on the performance monitoring counters (PMCs) of embedded platforms and demonstrates its portability, simplicity and accuracy for on-line estimation. It has two off-line procedure stages: the former, which automatically identifies the most appropriate PMCs with no specific detailed knowledge of the employed platform, and the latter, which trains the model using either a linear regression or a multivariable adaptive regression splines (MARS) method. Experimenting on an RVC-CAL decoder, the proposed PMC-driven model can achieve an average estimation error <10%. In addition, the maximal model computation overhead is 4.04%. The results show that the training video sequence has significant influence on the model accuracy. An experimental metric is introduced to achieve more stable accurate models based on a combination of training sequences. Furthermore, a comparison demonstrates better predictive ability of MARS techniques in scenarios with multi-core platforms. Finally, the experimental results show a good potential of energy efficiency improvement when the estimation model is combined into the RVC framework. In two different scenarios, the battery lifetime is increased 5.16% and 20.9%, respectively.

关键词： video coding video codecs regression analysis splines (mathematics) image sequences decoding platform-independent energy estimation methodology video decoders reconfigurable video coding performance monitoring counters energy consumption online estimation offline procedure stages linear regression method multivariable adaptive regression splines method MARS method RVC-CAL video codec specifications PMC-driven model accuracy model training video sequence predictive ability piecewise modelling techniques multicore platforms energy efficiency improvement

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