检索结果-南通市图书馆

维普期刊数据库博看期刊

radiography Image Classification Using Deep Convolutional Neural Networks

在线全文

学校读者我要写书评

暂无评论

Journal of Computer and Communications 2024年第6期12卷 199-209页

作者： Ahmad Chowdhury Haiyi Zhang Department of Computer Science Acadia University Wolfville Canada

research has shown that chest radiography images of patients with different diseases, such as pneumonia, COVID-19, SArS, pneumothorax, etc., all exhibit some form of abnormality. Several deep learning techniques can be used to identify each of these anomalies in the chest x-ray images. Convolutional neural networks (CNNs) have shown great success in the fields of image recognition and image classification since there are numerous large-scale annotated image datasets available. The classification of medical images, particularly radiographic images, remains one of the biggest hurdles in medical diagnosis because of the restricted availability of annotated medical images. However, such difficulty can be solved by utilizing several deep learning strategies, including data augmentation and transfer learning. The aim was to build a model that would detect abnormalities in chest x-ray images with the highest probability. To do that, different models were built with different features. While making a CNN model, one of the main tasks is to tune the model by changing the hyperparameters and layers so that the model gives out good training and testing results. In our case, three different models were built, and finally, the last one gave out the best-predicted results. From that last model, we got 98% training accuracy, 84% validation, and 81% testing accuracy. The reason behind the final model giving out the best evaluation scores is that it was a well-fitted model. There was no overfitting or underfitting issues. Our aim with this project was to make a tool using the CNN model in r language, which will help detect abnormalities in radiography images. The tool will be able to detect diseases such as Pneumonia, Covid-19, Effusions, Infiltration, Pneumothorax, and others. Because of its high accuracy, this research chose to use supervised multi-class classification techniques as well as Convolutional Neural Networks (CNNs) to classify different chest x-ray images. CNNs are extremely efficient and successful at reducing the n

关键词： CNN radiography Image Classification r Keras Chest X-ray Machine Learning

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

单裂隙类岩石蠕变力学特性及损伤演化规律

应用力学学报 2024年

作者：卢小雨谢雅董春亮张博文李直勇姚孟圆安徽理工大学力物与光电物理学院安徽理工大学土木建筑学院安徽理工大学深部煤矿采动响应与灾害防控国家重点实验室

为探究不同倾角裂隙岩体蠕变损伤演化规律及裂纹扩展特征，采用rDL系列电子蠕变松弛试验机和声发射（acoustic emission，简称AE）监测系统，对0°、30°、60°、90°四种倾角的试件分别开展单轴蠕变试验，分析其不同倾角裂隙试样蠕变... 详细信息

为探究不同倾角裂隙岩体蠕变损伤演化规律及裂纹扩展特征，采用rDL系列电子蠕变松弛试验机和声发射（acoustic emission，简称AE）监测系统，对0°、30°、60°、90°四种倾角的试件分别开展单轴蠕变试验，分析其不同倾角裂隙试样蠕变力学特性和声发射特征。研究结果表明：类岩石破坏强度受裂隙倾角影响较大，倾角为90°的试样破坏强度为0°试样的两倍；裂隙倾角一定时，轴向瞬时应变和蠕变应变随应力水平的增大均呈递增趋势；同一应力水平下的稳态蠕变速率，随裂隙倾角的增加呈现先增大后减小的趋势，30°蠕变速率最大，90°蠕变速率最小；试样的长期强度与裂隙倾角之间呈线性增长趋势；与轴向应变和累计振铃计数相比，声发射b值能够更有效的预测裂隙岩石的失稳破坏；声发射时空分布特征与蠕变三阶段的振铃计数和能量变化趋势较为一致；随着裂隙倾角的增加，rA（aise time/amplitude）呈现先增大后减小的趋势，表明在最后一级应力水平下剪切裂纹较张拉裂纹占比大。

关键词：预制裂隙损伤演化声发射 b值时空分布 r -A (average frequency)值

贝叶斯因子序列分析:实验设计中平衡信息与效率的新方法

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

应用心理学 2024年第2期30卷 158-171页

作者：郑元瑞胡传鹏南京师范大学心理学院南京210097 昆明城市学院教育学院昆明650106

实验设计的关键是平衡信息量与效率。贝叶斯因子序列分析利用贝叶斯因子不断更新证据的特点,通过贝叶斯因子标准和在收集数据过程中的序列分析来平衡信息量与效率。本文展示如何使用开源软件JASP和r实现该分析的三个步骤:确定关键效应... 详细信息

实验设计的关键是平衡信息量与效率。贝叶斯因子序列分析利用贝叶斯因子不断更新证据的特点,通过贝叶斯因子标准和在收集数据过程中的序列分析来平衡信息量与效率。本文展示如何使用开源软件JASP和r实现该分析的三个步骤:确定关键效应、确定停止标准、数据收集中序列分析并决策。该方法考虑现实条件且简单易行,可帮助研究者更有效地进行实验。

关键词：贝叶斯因子序列分析统计检验力实验设计 JASP r

Precipitation behavior of P550 steel for non-magnetic drill collars during isothermal aging at 650–900℃

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel research(International) 2022年第4期29卷 636-646页

作者： Li-wei Xu Huai-bei Zheng Hua-bing Li Zhou-hua Jiang Shu-cai Zhang Jiang-tao Yu Hao Feng Yue Lin School of Metallurgy Northeastern UniversityShenyang 110819LiaoningChina State Key Laboratory of Metal Material for Marine Equipment and Application Anshan 114002LiaoningChina

Precipitation behavior of P550 steel for non-magnetic drill collars was investigated by microstructure characterization as well as thermodynamic calculation.The results demonstrate that the main precipitate formed at 650–900℃was cellular Cr_(2)N,and its precipitation depended heavily on the aging temperature.The most sensitive precipitation temperature of cellular Cr_(2)N was 750℃.At 750℃,the cellular Cr_(2)N exhibited fast-slow precipitation kinetics with the aging time prolonging.The initial precipitation of cellular Cr_(2)N was governed by the short-range intergranular diffusion of Cr.During long-term aging,its growth was controlled by the long-range bulk diffusion of Cr.In addition,cellular Cr_(2)N induced the precipitation of r phase ahead of the cell after long period of aging.Increasing the nitrogen content resulted in the increment of both the nucleation site and the driving force for the cellular Cr_(2)N,which jointly promoted its precipitation.

关键词： P550 steel Non-magnetic drill collar Precipitation behavior Cellular Cr_(2)N r Phase Nitrogen

mrMLM v4.0.2: An r Platform for Multi-locus Genome-wide Association Studies

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Genomics, Proteomics & Bioinformatics 2020年第4期18卷 481-487页

作者： Ya-Wen Zhang Cox Lwaka Tamba Yang-Jun Wen Pei Li Wen-Long ren Yuan-Li Ni Jun Gao Yuan-Ming Zhang Crop Information Center College of Plant Science and TechnologyHuazhong Agricultural UniversityWuhan 430070China Department of Mathematics Egerton UniversityEgerton 536-20115Kenya State Key Laboratory of Crop Genetics and Germplasm Enhancement Nanjing Agricultural UniversityNanjing 210095China Department of Epidemiology and Medical Statistics School of Public HealthNantong UniversityNantong 226019China College of Informatics Huazhong Agricultural UniversityWuhan 430070China

Previous studies have reported that some important loci are missed in single-locus genome-wide association studies(GWAS),especially because of the large phenotypic error in field experiments.To solve this issue,multi-locus GWAS methods have been recommended.However,only a few software packages for multi-locus GWAS are available.Therefore,we developed an r software named mr MLM v4.0.2.This software integrates mr MLM,FASTmr MLM,FASTmr EMMA,p LArm EB,p KWm EB,and ISIS EM-BLASSO methods developed by our lab.There are four components in mr MLM v4.0.2,including dataset input,parameter setting,software running,and result output.The fread function in data.table is used to quickly read datasets,especially big datasets,and the do Parallel package is used to conduct parallel computation using multiple CPUs.In addition,the graphical user interface software mr MLM.GUI v4.0.2,built upon Shiny,is also available.To confirm the correctness of the aforementioned programs,all the methods in mr MLM v4.0.2 and three widely-used methods were used to analyze real and simulated datasets.The results confirm the superior performance of mr MLM v4.0.2 to other methods currently available.False positive rates are effectively controlled,albeit with a less stringent significance threshold.mr MLM v4.0.2 is publicly available at Bio Code(https://***/biocode/tools/BT007077)or r(https://***/web/packages/mr MLM.GUI/index.html)as an open-source software.

关键词： Genome-wide association study Linear mixed model mrMLM Multi-locus genetic model r

GAPIT Version 3: Boosting Power and Accuracy for Genomic Association and Prediction

在线全文

学校读者我要写书评

暂无评论

Genomics, Proteomics & Bioinformatics 2021年第4期19卷 629-640页

作者： Jiabo Wang Zhiwu Zhang Key Laboratory of Qinghai-Tibetan Plateau Animal Genetic resource reservation and Utilization Sichuan Province and Ministry of EducationSouthwest Minzu UniversityChengdu 610041China Department of Crop and Soil Sciences Washington State UniversityPullmanWA 99164USA

Genome-wide association study(GWAS)and genomic prediction/selection(GP/GS)are the two essential enterprises in genomic research.Due to the great magnitude and complexity of genomic and phenotypic data,analytical methods and their associated software packages are frequently advanced.GAPIT is a widely-used genomic association and prediction integrated tool as an r package.The first version was released to the public in 2012 with the implementation of the general linear model(GLM),mixed linear model(MLM),compressed MLM(CMLM),and genomic best linear unbiased prediction(g BLUP).The second version was released in 2016 with several new implementations,including enriched CMLM(ECMLM)and settlement of MLMs under progressively exclusive relationship(SUPEr).All the GWAS methods are based on the single-locus test.For the first time,in the current release of GAPIT,version 3 implemented three multi-locus test methods,including multiple loci mixed model(MLMM),fixed and random model circulating probability unification(Farm CPU),and Bayesian-information and linkage-disequilibrium iteratively nested keyway(BLINK).Additionally,two GP/GS methods were implemented based on CMLM(named compressed BLUP;c BLUP)and SUPEr(named SUPEr BLUP;s BLUP).These new implementations not only boost statistical power for GWAS and prediction accuracy for GP/GS,but also improve computing speed and increase the capacity to analyze big genomic data.Here,we document the current upgrade of GAPIT by describing the selection of the recently developed methods,their implementations,and potential impact.All documents,including source code,user manual,demo data,and tutorials,are freely available at the GAPIT website(http://***/GAPIT).

关键词： GWAS Genomic selection Software r GAPIT

Human antigen r mediated post-transcriptional regulation of inhibitors of apoptosis proteins in pancreatic cancer

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2019年第2期25卷 205-219页

作者： Ausra Lukosiute-Urboniene Aldona Jasukaitiene Giedre Silkuniene Vidmantas Barauskas Antanas Gulbinas Zilvinas Dambrauskas Institute for Digestive System research Lithuanian University of Health Sciences Department of Pediatric Surgery Lithuanian University of Health Sciences Department of Surgery Lithuanian University ofHealth Sciences

AIM To determine the association of human antigen r(Hur) and inhibitors of apoptosis proteins(IAP1, IAP2) and prognosis in pancreatic cancer.METHODS Protein and mrNA expression levels of IAP1, IAP2 and Hur in pancreatic ductal adenocarcinoma(PDAC) were compared with normal pancreatic tissue. The correlations among IAP1/IAP2 and Hur as well as their respective correlations with clinicopathological parameters were analyzed. The Kaplan-Meier method and log-rank tests were used for survival analysis. Immunoprecipitation assay was performed to demonstrate Hur binding to IAP1, IAP2 mrNA. PANC1 cells were transfected with either anti-Hur sirNA or control sirNA for 72 h and quantitative reverse transcription polymerase chain reaction(rT-PCr), western blot analysis was carried out.rESULTS rT-PCr analysis revealed that Hur, IAP1, IAP2 mrNA expression were accordingly 3.3-fold, 5.5-fold and 8.4 higher in the PDAC when compared to normal pancreas(P ression of IAP1 was positively strongly correlated with Hur expression(P r = 0.783). Western blot analysis confirmed rTPCr results. High IAP1 expression, tumor resection status, T stage, lymph-node metastases, tumor differentiation grade, perineural and lymphatic invasion were identified as significant factors for shorter survival in PDAC patients(P r was mainly expressed in the ductal cancer cell's nucleus and less so in cytoplasm. rNA immunoprecipitation analysis confirmed IAP1 and IAP2 post-transcriptional regulation by Hur protein. Following siHur transfection, IAP1 mrNA and protein levels were decreased, however IAP2 expression levels were increased.CONCLUSION Hur mediated overexpression of IAP1 significantly correlates with poor outcomes and early progression of pancreatic cancer. Further studies are needed to assess the underlying mechanisms.

关键词： Pancreatic cancer Inhibitors of apoptosis proteins Human antigen r Posttranscriptional regulation

A facile synthesis of novel optically active r,r-2-(4-(2-(4-(5-chloro-3-halo-pyridin-2-yloxy)-phenoxy)-propionyloxy)-phenoxy)-propionic acid esters using cyanuric chloride as potential herbicide

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2011年第5期22卷 535-538页

作者： Hassan Tajik Akbar Dadras Shokufeh Aghabeygi Department of Chemistry Faculty of SciencesUniversity of GuilanP.O.Box 41335-1914RashtIran Department of Chemistry Islamic Azad University East Tehran BranchP.O.Box 33955-163QiamdashtIran

A facile method for the synthesis of a new series of r,r-2-（4-（2-（4-（5-chloro-3-halopyridin-2-yloxy）-phenoxy）-propionyloxy）-phenoxy） -propionic acid ester derivatives containing a halo-substituted pyridine carrying two r,r chiral centers from（r）-2-（4- hydroxyphenoxy）propionic acid,halopyridines and alcohols using base/cyanuric chloride/catalyst system is reported.Their herbicidal activities against grass weeds and crops selectivity were evaluated.

关键词： Aryloxyphenoxypropionic acid Chiral herbicide Cyanuric chloride Esters r r-Diastereomer

Anisotropic Transport and Magnetic Properties of Charge-Density-Wave Materials rSeTe2（r=La,Ce,Pr,Nd）

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2015年第8期32卷 127-131页

作者：王培培龙雨佳赵凌霄陈栋薛面起陈根富 Institute of Physics and Beijing National Laboratory for Condensed Matter Physics Chinese Academy of Sciences Beijing 100190 Department of Physics Renmin University of China Beijing 100872 Collaborative Innovation Center of Quantum Matter Beijing 100190

Single crystals of rSeTe2 （r =La, Ce, Pr, Nd） are synthesized using LiC1/rbCI flux. Transport and magnetic properties in the directions parallel and perpendicular to the a-c plane are investigated. We find that the resistivity anisotropy P⊥/P∥ lies in the range 486-615 for different compounds at 2K, indicating the highly two-dimensional character. In both the orientations, the charge-density-wave transitions start near Tcow = 284（3）K, 316（3）K, 359（3）K for NdSeTe2, PrSeTe2, CeSeTe2, respectively, with a considerable increase in dc resistivity. While for LaSeTe2, no obvious resistivity anomaly is observed up to 380K. The value of TCDW increases monotonically with the increasing lattice parameters. Below TCDW, slight anomalies can be observed in NdSeTe2, PrSeTe2 and CeSeTe2 with onset temperature at 193（3）K, 161（3）K, 108（3）K, respectively, decreasing as lattice parameters increase. Magnetic susceptibility measurements show that the valence state of rare earth ions are trivalenee in these compounds. Antiferromagnetie-type magnetic order is formed in CeSeTe2 at 2.1 K, while no magnetic transition is observed in PrSeTe2 and NdSeTe2 down to 1.8 K.

关键词： r=La,Ce,Pr,Nd Te CDW Anisotropic Transport and Magnetic Properties of Charge-Density-Wave Materials rSeTe2 r Ce La