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148篇 您的检索式:作者名="Haijian"
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1Failure mechanism and stability control of a large section of very soft roadway surrounding rock shear slip显示文摘The measured data and simulation test phenomenon of surrounding rock deformation and failure at the project site indicate that shear failure which firstly occurs in surrounding rock, block slip and second shear failure are the root cause of deformation and damage of supporting structure of the surrounding rock at a large scale. We derived limit load of surrounding rock shear slip failure and reasonable support resistance of given load by means of shear slip line field theory, discussed the main factors which influence the limit load of surrounding rock. Shear slip line field and limit load of circular tunnel surrounding rock were obtained by means of physical simulation test, which agreed well with the theoretical analysis results. Based on the theoretical analysis and physical simulation test, the cause deformation and failure at large scale of Xinshanghai No. 1 coal mine big section ingate was analyzed, and the shear failure resistance and block slip in surrounding rock were proposed as the core technical supporting ideas. Proper range of supporting resistance which came from calculation was suggested. The support scheme which is mainly composed of large grouting anchor, sprayed anchor net support technique and full-face grille concrete finally ended the dilemma of repeated failure and mending of ingate and created critical conditions for smooth production in the coal mine.Meng Bo Jing Hongwen Chen Kunfu Su Haijian 2013International Journal of Mining Science and Technology2013,23,1:22
2Historical trends of heavy metal contamination and their sources in lacustrine sediment from Xijiu Lake,Taihu Lake Catchment,China显示文摘Concentrations of Cd,Cr,Cu,Pb,Zn and Hg in Xijiu Lake sediment from the Taihu Lake catchment,China,were analyzed.Their contamination state was investigated based on the geoaccumulation index and enrichment factors.Statistical analysis was used to differentiate the anthropogenic versus natural sources of heavy metals (HMs),and the anthropogenic accumulation fluxes were calculated to quantify anthropogenic contribution to HMs.The results indicated that the lake sediment had been heavily contaminated by Cd,enrichment of Zn and Hg was at a relatively high level,while that of Cu and Pb was in the lower-to-moderate level and Cr was in the low enrichment level.Sources of Cr in the sediment were mainly from natural inputs,while other metals,especially Cd,were predominantly derived from anthropogenic sources.In the past century,anthropogenic accumulation fluxes of Pb,Zn and Hg increased by 0.1-47.3 mg/(cm2·yr),2.4-398.1 mg/(cm2·yr),and 3.7-110.3 ng/(m2·yr),respectively,accounting for most inputs of HMs entering the sediment.The contamination state of HMs varied with industrial development of the catchment,which demonstrated that contamination started in the early 20th century,reached the maximal level between the mid-1970s and mid-1990s,and decreased a little after the implementation of constraints on high contamination industries,although the contamination of some HMs,such as Cd,Zn and Hg,is still at high levels.Haijian Bing Yanhong Wu Zhaobin Sun Shuchun Yao 2011Journal of Environmental Sciences2011,23,10:18
3Physical and mechanical properties of sandstone containing a single fissure after exposure to high temperatures显示文摘In order to investigate the physical and mechanical properties of sandstone containing fissures after exposure to high temperatures,fissures with different angles α were prefabricated in the plate sandstone samples,and the processed samples were then heated at 5 different temperatures.Indoor uniaxial compression was conducted to analyze the change rules of physical properties of sandstone after exposure to high temperature,and the deformation,strength and failure characteristics of sandstone containing fissures.The results show that,with increasing temperature,the volume of sandstone increases gradually while the quality and density decrease gradually,and the color of sandstone remains basically unchanged while the brightness increases markedly when the temperature is higher than 585 ℃;the peak strength of sandstone containing fissures first decreases then increases when the temperature is between 25℃and 400℃.The peak strain of sandstone containing fissures increases gradually while the average modulus decreases gradually with increasing temperature,and the mechanical properties of sandstone show obvious deterioration after 400 ℃.The peak strain of sandstone containing fissures increases gradually while the average modulus decreases gradually with increasing temperature;with increasing angle αof the fissure,the evolution characteristics of the macro-mechanical parameters of sandstone are closely related to the their own mechanical properties.When the temperature is 800 ℃,the correlation between the peak strength and average modulus of sandstone and the angle α of the fissure is obviously weakened.The failure modes of sandstone containing fissures after high temperature exposure are of three different kinds including:tensile crack failure,tensile and shear cracks mixed failure,and shear crack failure.Tensile and shear crack mixed failure occur mainly at low temperatures and small angles;tensile crack failure occurs at high temperatures and large angles.Zhu Tantan Jing Hongwen Su Haijian Yin Qian Du Mingrui Han Guansheng 2016International Journal of Mining Science and Technology2016,26,2:15
4Assessment of heavy metal enrichment and its human impact in lacustrine sediments from four lakes in the mid-low reaches of the Yangtze River, China显示文摘Sediments from four lakes in the mid-low reaches of the Yangtze River, Taibai Lake, Longgan Lake, Chaohu Lake and Xijiu Lake, were chosen to evaluate their enrichment state and history. The state of heavy metal enrichment was at a low level in the sediment of Taibai Lake and Longgan Lake. The enrichment state of Co, Cr and Ni was also low in the sediment of Chaohu Lake and Xijiu Lake, while Cu, Pb and Zn enrichment reached a higher level. Mass accumulation fluxes were calculated to quantitatively evaluate the anthropogenic contribution to heavy metals in the sediment. The anthropogenic accumulation fluxes were lower in the sediment of Taibai Lake and Longgan Lake compared with the other two lakes, where heavy metals, especially Cu, Pb and Zn, were mainly from anthropogenic sources. Heavy metal accumulation did not vary greatly in the sediment of Taibai Lake and Longgan Lake, while that in Chaohu Lake and Xijiu Lake increased since the 1950s and substantially increased since the 1980s, although a decrease occurred since 2000 AD in Xijiu Lake. Heavy metal enrichment was strongly related to human activities in the catchment. The development of urbanization and industrialization was much more rapid in the catchments of Chaohu Lake and Xijiu Lake than of the other two lakes, and thus large amounts of anthropogenically sourced heavy metals were discharged into the lakes, which resulted in a higher contamination risk. However, human activities in the Longgan Lake and Taibai Lake catchments mainly involved agriculture, which contributed a relatively small portion of heavy metals to the lakes.Haijian Bing Yanhong Wu Enfeng Liu Xiangdong Yang 2013Journal of Environmental Sciences2013,25,7:14
5Transforming bacterial disease surveillance and investigation using whole-genome sequence to probe the trace显示文摘二十年后来过去了第一细菌的整个染色体的定序,它为微生物引起的染色体提供新机会。因而,可观的基因差异由细菌的染色体编码了,在在一样的种类之中,种类被揭示了。在最近的年里,染色体定序技术和生物信息学很快发展了,它导致了转变并且为在传染疾病流行病的解剖使用的细菌的染色体比较帮助了策略和方法论的应用程序。细菌的整个染色体的定序并且生物信息的计算允许 genotyping 在疾病控制满足流行病学的学习的要求。在这评论,我们构画出意义并且总结细菌的染色体在细菌的疾病控制和预防的上下文定序的角色。我们讨论细菌的染色体在爆发察觉,跟踪的来源,传播模式发现,和新流行克隆定序的应用程序鉴定。染色体在传染疾病监视网络定序并且数据分享的宽应用程序将更加支持爆发察觉和早警告阻止细菌的疾病的传播。Biao Kan Haijian Zhou Pengcheng Du Wen Zhang Xin Lu Tian Qin Jianguo Xu 2018Frontiers of Medicine2018,12,1:11
6Fracture evolution characteristics of sandstone containing double fissures and a single circular hole under uniaxial compression显示文摘The uniaxial compression experiments on the sandstone samples containing double fissures and a single circular hole were carried out by using electro-hydraulic servo universal testing machine to investigate the effect of rock bridge angle β and fissure angle α on mechanical properties and evolution characteristics of cracks.The results show that the peak strength,peak strain and elastic modulus of defected specimens decrease comparing with those for intact sample,and show a decreased trend firstly and then increase with β changing from 0° to 90°.The peak strength and elastic modulus achieve the minimum value as the rock bridge angle is 60°,while the peak strain reaches the minimum value with the rock bridge angle of 45°.The crack initiation of tested rock samples occurs firstly in stress concentration areas at tips of prefabricated fissures under uniaxial compression,and then propagates constantly and coalescences with the prefabricated hole.Some secondary cracks initiate and propagate as well until buckling failure happens.The rock bridge angle has a great influence on crack initiation,coalescence,final failure mode,crack initiation stress and transfixion stress.The peak strength varies significantly,while the elastic modulus and peak strain change slightly,and the failure modes are also different due to the influence of fissure angle.Chen Minliang Jing Hongwen Ma Xiujun Su Haijian Du Mingrui Zhu Tantan 2017International Journal of Mining Science and Technology2017,27,3:11
7Nucleocytoplasmic Trafficking of the Arabidopsis WD40 Repeat Protein XIW1 Regulates ABI5 Stability and Abscisic Acid Responses显示文摘WD40 repeat-containing proteins(WD40 proteins)serve as versatile scaffolds for protein-protein interac-tions,modulating a variety of cellular processes such as plant stress and hormone responses.Here we report the identification of a WD40 protein,XIW1(for XPO1-interacting WD40 protein 1),which positively regulates the abscisic acid(ABA)response in Arabidopsis.XIW1 is located in the cytoplasm and nucleus.We found that it interacts with the nuclear transport receptor XPO1 and is exported by XPO1 from the nucleus.Mutation of XIW1 reduces the induction of ABA-responsive genes and the accumulation of ABA Insensitive 5(ABI5),causing mutant plants with ABA-insensitive phenotypes during seed germination and seedling growth,and decreased drought stress resistance.ABA treatment upregulates the expression of XIW1,and both ABA and abiotic stresses promote XIW1 accumulation in the nucleus,where it interacts with ABI5.Loss of XIW1 function results in rapid proteasomal degradation of ABI5.Taken together,these findings suggest that XIW1 is a nucleocytoplasmic shuttling protein and plays a positive role in ABA responses by interacting with and maintaining the stability of ABI5 in the nucleus.Xuezhong XU Wang Wan Guobin Jiang Yue Xi Haijian Huang Jiajia Cai Yanan Chang Cheng-Guo Duan Satendra KMangrauthia Xinxiang Peng Jian-Kang Zhu Guohui Zhu 2019Molecular Plant2019,12,12:8
8An analytical solution to contaminant advection and dispersion through a GCL/AL liner system显示文摘An one-dimensional model for contaminant advection and dispersion through a GCL/AL liner system was developed to analyze the equivalence between a GCL(geosynthetic clay liner) and a CCL(compacted clay liner).The continuity of contaminant concentration and flux at the interface between the GCL and the underlying attenuation liner(AL) are obeyed in the model,and background concentrations in the soil liner are also considered.Based on the assumption that contaminant transport through a GCL was a steady state process,an analytical solution was obtained.Increasing the leachate head from 0.3 m to 10 m results in a reduction of the breakthrough time of benzene by a factor of 2.7.The breakthrough time of benzene increases by a factor of 7.0 when the hydraulic conductivity of GCL decreases by one order of magnitude.The breakthrough curves are more sensitive to the hydraulic conductivities of the GCL and AL(attenuation layer) than to the thickness of the AL.The standard 75 cm CCL can be replaced by a combination of a GCL and a 1.0-4.0 m thickness of AL.The proposed method can be used for preliminary design of GCL composite liners,assessing the equivalence between GCL and CCL,preliminary design of a remediation method for contaminated soils,and evaluating experimental results.XIE HaiJian LOU ZhangHua CHEN YunMin JIN AiMin CHEN PeiXiong 2011Chinese Science Bulletin2011,56,8:8
9Nucleation mechanisms of dynamic recrystallization in Inconel 625 superalloy deformed with different strain rates显示文摘The effects of strain rates on the hot working characteristics and nucleation mechanisms of dynamic recrystallization (DRX) were studied by optical microscopy and electron backscatter diffraction (EBSD) technique. Hot compression tests were conducted using a Gleeble-1500 simulator at a true strain of 0.7 in the temperature range of 1000 to 1150 °C and strain rate range of 0.01 to 10.00 s-1. It is found that the size and volume fraction of the DRX grains in hot-deformed Inconel 625 superalloy firstly decrease and then increase with increasing strain rate. Meanwhile, the nucleation mechanism of DRX is closely related to the deformation strain rate due to the deformation thermal effect. The discontinuous DRX (DDRX) with bulging of original grain boundaries is the primary nucleation mechanism of DRX, while the continuous DRX (CDRX) with progressive subgrain rotation acts as a secondary nucleation mechanism. The twinning formation can activate the nucleation of DRX. The effects of bulging of original grain boundaries and twinning formation are firstly gradually weakened and then strengthened with the increasing strain rate due to the deformation thermal effect. On the contrary, the effect of subgrain rotation is firstly gradually strengthened and then weakened with the increasing strain rate.Guo, Qingmiao Li, Defu Peng, Haijian Guo, Shengli Hu, Jie Du, Peng 2012Rare Metals2012,31,3:8
10Analysis of diffusion-adsorption equivalency of landfill liner systems for organic contaminants显示文摘The equivalence between multilayered barriers regarding diffusion and adsorption was studied. The bottom boundary of the liner system is defined by assuming concentration continuous and flux continuous conditions of the contaminant between the bottom liner layer and the underlying soil. Five different liner systems were compared in terms of solute breakthrough time. The results of the analysis showed that breakthrough time of the hydrophobic organic compounds for a 2-meter-thick compacted clay liner (CCL) could be 3-4 orders of magnitude is greater than the breakthrough time for a geosynthetic clay liner (GCL) composite liner. The GM/GCL and GM/CCL composite liner systems provide a better diffusion barrier for the hydrophilic organic compounds than that for the hydrophobic compounds due to their different Henry's coeffcient. The calculated breakthrough times of the organic contaminants for the Chinese standard liner systems were found to be generally greater than those for the GCL alternatives, for the specific conditions examined. If the distribution coeffcient increases to 2.8 for the hydrophobic compounds or 1.0 for the hydrophilic compounds, the thickness of the attenuation layer needed to achieve the same breakthrough time as the standard liner systems can be reduced by a factor of about 1.9-2.4. As far as diffusive and adsorption contaminant transport are concerned, GM or GCL is less effective than CCL.XIE Haijian, CHEN Yunmin, KE Han, TANG Xiaowu, CHEN Renpeng MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Zhejiang University, Hangzhou 310027, China. 2009Journal of Environmental Sciences2009,21,4:8
11Strength and deformation behaviors of bedded rock mass under bolt reinforcement显示文摘The mechanism of bolt support is an important topic in mining engineering and slope treatment. The artificial material and loading system were self-developed to study the influence of bedding cohesion and bolt number on the anchoring behavior of bedded rock mass. The results show that, both peak strength and elasticity modulus increase gradually with the increase of bedding cohesion and bolt number. The axial stress–strain curve of bedded rock mass under the reinforcement of bolts presents the features of strain-softening and secondary strengthening. Finally, anchoring behavior of bedded rock mass with different bolt numbers was simulated by using FLAC3 D numerical program and the results were compared with the experimental results. This study can provide certain bases to the stability control and support design of bedded rock mass in roadway.Wenxin Zhu Hongwen Jing Lijun Yang Bing Pan Haijian Su 2018International Journal of Mining Science and Technology2018,28,4:7
12Soil phosphorus bioavailability assessed by XANES and Hedley sequential fractionation technique in a glacier foreland chronosequence in Gongga Mountain, Southwestern China显示文摘The primary productivity of terrestrial ecosystems is influenced by soil phosphorus bioavailability, which depends largely on chemical fractions of phosphorus. The sequential fractionation technique developed by Hedley et al. or its subsequent modification is a well-known method to determine soil phosphorus forms. Hedley sequential fractionation technique separates the phosphorus into fractions based on their different chemical solubilities in extractants with certain chemical properties. Recently, synchrotron-based X-ray absorption near edge structure(XANES) spectroscopy has been employed to measure soil phosphorus species directly and non-invasively. The XANES method provides information concerning local structure and chemical information of target elements at a molecular level. Thus, it can distinguish phosphorus fractions bound by metal oxides or hydroxides(such as Fe, Al, and Ca). In this present work, the phosphorus speciation of topsoil along a glacial foreland chronosequence in Gongga Mountain is determined using these two methods. The changes in soil phosphorus bioavailability along the 120-year-old chronosequence are assessed based on comparisons of the results obtained by these two methods. The results indicate that Hedley sequential fractionation technique shows a greater ability to determine soil bioavailable phosphorus(Resin-P and NaCHO3-P), while XANES is effective in distinguishing phosphorus bound by metal compounds. In the chronosequence, Ca- and Al-bound phosphorus were derived mainly from primary minerals, whose phosphorus contents decreased within 120 years of moraine weathering and soil development. The content of soil bioavailable phosphorus increased rapidly after 30 years since deglaciation. The increasing phosphorus bioavailability promoted the colonizing and primary succession vegetation.WU YanHong Jrg PRIETZEL ZHOU Jun BING HaiJian LUO Ji YU Dong SUN ShouQin LIANG JianHong SUN HongYang 2014Science China Earth Sciences2014,57,8:6
13A review:Modification strategies of nickel-rich layer structure cathode(Ni≥0.8)materials for lithium ion power batteries显示文摘Lithium ion power batteries have undoubtedly become one of the most promising rechargeable batteries at present;nonetheless,they still suffer from the challenges such as requirement of even higher energy density and capacity retention.Nickel-rich layer oxides(Ni≥0.8)become ideal cathode materials to achieve the high specific capacity.Integration of optimization of synthesis process and modification of crystal structure to suppress the capacity fading can obviously improve the performance of the lithium ion batteries.This review presents the recent modification strategies of the nickel-rich layered oxide materials.Unlike in previous reviews and related papers,the specific mechanism about each type of the modification strategies is specially discussed in detail,which is mainly about inhibiting the anisotropic lattice strain and adjusting the cation mixing degree to maintain crystal structure.Based on the recent progress,the prospects and challenges of the modified nickel-rich layer cathodes to upgrade the property of lithium ion batteries are also comprehensively analyzed,and the potential applications in the field of plug-in hybrid vehicles and electric vehicles are further discussed.Haijian Lv Chunli Li Zhikun Zhao Borong Wu Daobin Mu 2021Journal of Energy Chemistry2021,30,9:6
14Experimental and numerical investigations on the tensile mechanical behavior of marbles containing dynamic damage显示文摘To investigate the degradation mechanism of static tensile mechanical behaviors of marble containing dynamic damage,multiple impact loading tests were performed on the disc marble samples,and then static Brazilian tests were conducted for the damaged samples.Besides,coupling modeling technology of finite difference method(FDM)—discrete element method(DEM)was used to carry out the numerical investigation.The results show that after multiple impacts,more white patches appear on the surface,and some microcracks,macro-fractures as well as pulverized grains are found by optical microscopic.The static tensile strength decreases with the increase of the dynamic damage variable characterized by the ultrasonic wave velocity of sample.The interaction between grains in the damaged sample becomes intense in the subsequent static loading process,causing a relatively large strain.The volume of the fragments falling off around the loading points becomes larger as impact number increases.As the dynamic damage increases,the absorbed energy of sample during the static loading first decreases and then tends to be stable.Both the stress concentration and the breakage of the force chains are the root causes of the degradation of the static tensile strength.Tao Zhang Liyuan Yu Haijian Su Qiang Zhang Shaobo Chai 2022International Journal of Mining Science and Technology2022,32,1:5
15Strength and deformation behaviors of veined marble specimens after vacuum heat treatment under conventional triaxial compression显示文摘The mechanical behaviors of rocks affected by high temperature and stress are generally believed to be significant for the stability of certain projects involving rocks, such as nuclear waste storage and geothermal resource exploitation. In this paper, veined marble specimens were treated to high temperature treatment and then used in conventional triaxial compression tests to investigate the effect of temperature, confining pressure, and vein angle on strength and deformation behaviors. The results show that the strength and deformation parameters of the veined marble specimens changed with the temperature, presenting a critical temperature of 600℃. The triaxial compression strength of a horizontal vein(β = 90°) is obviously larger than that of a vertical vein(β = 0°). The triaxial compression strength,elasticity modulus, and secant modulus have an approximately linear relation to the confining pressure. Finally,Mohr–Coulomb and Hoek–Brown criteria were respectively used to analyze the effect of confining pressure on triaxial compression strength.Haijian Su Hongwen Jing Qian Yin Liyuan Yu Yingchao Wang Xingjie Wu 2017Acta Mechanica Sinica2017,33,5:5
16Geochronology of recent lake sediments from Longgan Lake,middle reach of the Yangtze River,influenced by disturbance of human activities显示文摘The impacts of human activities in Longgan Lake region on the distribution of 210Pb in lake sediment made it difficult to establish geochronological sequence. However, environmental proxies recorded these human activities and could be used as time marker to check 210Pb dating results. Based on the analysis of 210Pbexc distribution in cores LS-1 and LGL-1, and in combination with the human activities records in grain-size and element concentration, the sedimentation rates in the upper layers of these two cores were determined to be 0.19 and 0.23 cm/a respectively. The MAR (mass accumulation rates) of these two cores demonstrated that natural condition, such as precipitation and runoffs, led to the variation of MAR before human disturbance, and human activities controlled the sedimentary processes afterwards, which obviously reduced the particles influx into the lakes. During 1940s when human activity had not changed the water system within the catchment, 210Pb activity was abnormally strong in lakes along middle to lower reaches of the Yangtze River, which might be attributed to less precipitation and can be used as a time marker for geochronological research.WU YanHong LIU EnFeng BING HaiJian YANG XiangDong XUE Bin XIA WeiLan 2010Science China Earth Sciences2010,53,8:4
17Mechanical properties of irradiated multi-phase polycrystalline BCC materials显示文摘Structure materials under severe irradiations in nuclear environments are known to degrade because of irradiation hardening and loss of ductility,resulting from irradiation-induced defects such as vacancies,interstitials and dislocation loops,etc.In this paper,we develop an elastic-viscoplastic model for irradiated multi-phase polycrystalline BCC materials in which the mechanical behaviors of individual grains and polycrystalline aggregates are both explored.At the microscopic grain scale,we use the internal variable model and propose a new tensorial damage descriptor to represent the geometry character of the defect loop,which facilitates the analysis of the defect loop evolutions and dislocation-defect interactions.At the macroscopic polycrystal scale,the self-consistent scheme is extended to consider the multiphase problem and used to bridge the individual grain behavior to polycrystal properties.Based on the proposed model,we found that the work-hardening coefficient decreases with the increase of irradiation-induced defect loops,and the orientation/loading dependence of mechanical properties is mainly attributed to the different Schmid factors.At the polycrystalline scale,numerical results for pure Fe match well with the irradiation experiment data.The model is further extended to predict the hardening effect of dispersoids in oxide-dispersed strengthened steels by the considering the Orowan bowing.The influences of grain size and irradiation are found to compete to dominate the strengthening behaviors of materials.Dingkun Song Xiazi Xiao Jianming Xue Haijian Chu Huiling Duan 2015Acta Mechanica Sinica2015,31,2:4
18A Classification–Detection Approach of COVID-19 Based on Chest X-ray and CT by Using Keras Pre-Trained Deep Learning Models显示文摘The Coronavirus Disease 2019(COVID-19)is wreaking havoc around the world,bring out that the enormous pressure on national health and medical staff systems.One of the most effective and critical steps in the fight against COVID-19,is to examine the patient’s lungs based on the Chest X-ray and CT generated by radiation imaging.In this paper,five keras-related deep learning models:ResNet50,InceptionResNetV2,Xception,transfer learning and pre-trained VGGNet16 is applied to formulate an classification-detection approaches of COVID-19.Two benchmark methods SVM(Support Vector Machine),CNN(Conventional Neural Networks)are provided to compare with the classification-detection approaches based on the performance indicators,i.e.,precision,recall,F1 scores,confusion matrix,classification accuracy and three types of AUC(Area Under Curve).The highest classification accuracy derived by classification-detection based on 5857 Chest X-rays and 767 Chest CTs are respectively 84%and 75%,which shows that the keras-related deep learning approaches facilitate accurate and effective COVID-19-assisted detection.Xing Deng Haijian Shao Liang Shi Xia Wang Tongling Xie 2020Computer Modeling in Engineering & Sciences2020,,11:4
19AdaBoosting Neural Network for Short-Term Wind Speed Forecasting Based on Seasonal Characteristics Analysis and Lag Space Estimation显示文摘High accurary in wind speed forcasting remains hard to achieve due to wind’s random distribution nature and its seasonal characteristics.Randomness,intermittent and nonstationary usually cause the portion problem of the wind speed forecasting.Seasonal characteristics of wind speed means that its feature distribution is inconsistent.This typically results that the persistence of excitation for modeling can not be guaranteed,and may severely reduce the possibilities of high precise forecasting model.In this paper,we proposed two effective solutions to solve the problems caused by the randomness and seasonal characteristics of the wind speed.(1)Wavelet analysis is used to extract the robust components of time series and reduce the influence of randomness.(2)Based on the energy distribution about the extracted amplitude and associated frequency,seasonal characteristics of wind speed are analyzed based on self-similarity in periodogram under scales range generated by wavelet transformation.Thus,the original dataset is reasonably divided into subsest which can effectively reflect the seasonal distribution characteristics of wind speed.In addition,two strategies are given to optimal model structure and improve the forecasting accuracy:(1)The forecasting model’s lag space is approximately estimated by the Lipschitz quotient to improve the generality ability of the feedforward neural network.(2)The forecasting accuracy and model robustness are further improved by the wavelet decomposition combined with AdaBoosting neural network.Finally,experimental evaluation based on the dataset from National Renewable Energy Laboratory(NREL)is given to demonstrate the performance of the proposed approach.Haijian Shao Xing Deng 2018Computer Modeling in Engineering & Sciences2018,,3:4
20Cucumber appearance quality detection under complex background based on image processing显示文摘Cucumber fruit appearance quality is an important basis of growth status.In order to improve the quality detection accuracy and processing efficiency of cucumber color image under complicated background,an improved GrabCut algorithm was proposed to extract the cucumber boundary.Firstly,including pixel size normalization,rectangular box set and scale image resolution,pretreatments of cucumber image were adopted to reduce the iteration times and operation time of GrabCut algorithm.Then,the Gaussian mixture model was chosen to find out the possible prospect of target region and background region in the preprocessed rectangular frame on the preliminary modeling.Meanwhile,by the optimization of K-means cluster to the initial GMM model,the effective target area was extracted.Finally,the whole image noise and serrated boundary was removed by morphological operations to segment the outline of the complete target prospects with appropriate structure size.And then the cucumber appearance quality detection instrument was designed to extract the texture and shape features exactly,so that it could obtain cucumber appearance quality and evaluate its growth effectively.With the segmentation experiments by almost 300 cucumber original images from greenhouse in Shandong Province,the results showed that the improved GrabCut algorithm could effectively extract the complete and smooth boundary of cucumber.With relatively high segmentation evaluation index,the precision was 93.88%,the recall rate was 99.35%,the F-Measure reached 96.53%,and the misclassification error was controlled at minimum 5.84%.The average running time was shortened to 1.4023 s.The comparison results showed that the improved GrabCut algorithm was the best,followed by the SLIC and traditional GrabCut method.Cucumber appearance quality detection instrument could also extract more accurate feature parameters.And it could meet the basic growth condition assessment by automatic image processing.Haijian Ye Chengqi Liu Peiyun Niu 2018International Journal of Agricultural and Biological Engineering2018,11,4:4
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