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A new approach to learning and recognizing leaf diseases from individual lesions using convolutional neural networks

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Information Processing in Agriculture 2023年第1期10卷 11-27页

作者： lawrence c.ngugi Moataz Abdelwahab Mohammed Abo-Zahhad Department of Electronics and communication Engineering Egypt-Japan University of Science and TechnologyAlexandriaEgypt Department of Electrical and Electronics Engineering Assiut UniversityAssiutEgypt

Leaf disease recognition using image processing and deep learning techniques is currently a vibrant research *** studies have focused on recognizing diseases from images of whole *** approach limits the resulting models’ability to estimate leaf disease severity or identify multiple anomalies occurring on the same *** studies have demonstrated that classifying leaf diseases based on individual lesions greatly enhances disease recognition *** those studies,however,the lesions were laboriously cropped by *** study proposes a semi-automatic algorithm that facilitates the fast and efficient preparation of datasets of individual lesions and leaf image pixel maps to overcome this *** datasets were then used to train and test lesion classifier and semantic segmentation convolutional Neural Network(cNN)models,*** report that GoogLeNet’s disease recognition accuracy improved by more than 15%when diseases were recognized from lesion images compared to when disease recognition was done using images of whole leaves.A cNN model which performs semantic segmentation of both the leaf and lesions in one pass is also proposed in this *** proposed KijaniNet model achieved state-of-the-art segmentation performance in terms of mean Intersection over Union(mIoU)score of 0.8448 and 0.6257 for the leaf and lesion pixel classes,*** terms of mean boundary F1 score,the KijaniNet model attained 0.8241 and 0.7855 for the two pixel classes,***,a fully automatic algorithm for leaf disease recognition from individual lesions is *** algorithm employs the semantic segmentation network cascaded to a GoogLeNet classifier for lesion-wise disease *** proposed fully automatic algorithm outperforms competing methods in terms of its superior segmentation and classification performance despite being trained on a small dataset.

关键词： Deep learning Precision agriculture Leaf disease recognition complex background removal Leaf image segmentation Lesion classification

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Recent advances in image processing techniques for automated leaf pest and disease recognition – A review

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Information Processing in Agriculture 2021年第1期8卷 27-51页

作者： lawrence c.ngugi Moataz Abelwahab Mohammed Abo-Zahhad Department of Electronics and communication Engineering Egypt-Japan University of Science and TechnologyP.O.Box 179New Borg El-Arab CityPostal Code 21934AlexandriaEgypt Department of Electrical and Electronics Engineering Assiut UniversityP.O.Box 71515AssiutEgypt

Fast and accurate plant disease detection is critical to increasing agricultural productivity in a sustainable ***,human experts have been relied upon to diagnose anomalies in plants caused by diseases,pests,nutritional deficiencies or extreme ***,this is expensive,time consuming and in some cases *** counter these challenges,research into the use of image processing techniques for plant disease recognition has become a hot research *** this paper,we provide a comprehensive review of recent studies carried out in the area of crop pest and disease recognition using image processing and machine learning *** hope that this work will be a valuable resource for researchers in this area of crop pest and disease recognition using image processing *** particular,we concentrate on the use of RGB images owing to the low cost and high availability of digital RGB *** report that recent efforts have focused on the use of deep learning instead of training shallow classifiers using handcrafted *** have reported high recognition accuracies on particular datasets but in many cases,the performance of those systems deteriorated significantly when tested on different datasets or in field ***,progress made so far has been *** results showing the leaf disease recognition performance of ten cNN architectures in terms of recognition accuracy,recall,precision,specificity,F1-score,training duration and storage requirements are also ***,recommendations are made on the most suitable architectures to deploy in conventional as well as mobile/embedded computing *** also discuss some of the unresolved challenges that need to be addressed in order to develop practical automatic plant disease recognition systems for use in field conditions.

关键词： Precision agriculture Machine learning Plant disease recognition Image processing convolutional neural networks

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Projective Hilbert modules and sequential approximations

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Science china Mathematics 2025年第1期 137-168页

作者： lawrence G.Brown Huaxin Lin Department of Mathematics Purdue University Department of Mathematics East China Normal University Department of Mathematics University of Oregon Shanghai Institute for Mathematics and Interdisciplinary Sciences

We show that when A is a separable c*-algebra,every countably generated Hilbert A-module is projective（with bounded module maps as morphisms）.We also study the approximate extensions of bounded module *** the case where A is a σ-unital simple c*-algebra with strict comparison,and every strictly positive lower semicontinuous affine function on quasitraces can be realized as the rank of an element in the cuntz semigroup,we show that the cuntz semigroup is equivalent to unitarily equivalent classes of countably generated Hilbert A-modules if and only if A has stable rank one.

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Ideal class groups and their subgroups of real quadratic fields

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Science china Mathematics 1997年第9期40卷 909-916页

作者：张贤科 lawrence c.Washington Department of Mathematics Tsinghua UniversityBeijing 100084China Department of Mathematics University of MarylandCollege ParkMD 20742USA

A necessary and sufficient condition is given for the ideal class group H( m } of a real quadratic field Q (m)to contain a cyclic subgroup of order *** criteria satisfying the condition are also *** eight types of such fields are proved to have this property,*** with m=(zn+t+12)+4t(with t|zn-1),which contains the well-known fields with m=4zn+1 and m=z2n+4 as special cases.

关键词： real quadratic field ideal class group class number.

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Morphology and orientation evolution of cu_(6)Sn_(5)grains on(001)cu and(011)cu single crystal substrates under temperature gradient

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Journal of Materials Science & Technology 2021年第36期95卷 29-39页

作者： Yuanyuan Qiao Xiaoying Liu Ning Zhao lawrence c M Wu chunying Liu Haitao Ma School of Materials Science and Engineering Dalian University of TechnologyDalian 116024China Department of Materials Science and Engineering City University of Hong KongHong Kong Special Administrative RegionChina

The morphology and orientation evolution of cu_(6)Sn_(5)grains formed on(001)cu and(011)cu single crystal substrates under temperature gradient(TG)were *** initial orientated prism-type cu_(6)Sn_(5)grains transformed to non-orientated scallop-type after isothermal ***,the cu_(6)Sn_(5)grains with strong texture were revealed on cold end single crystal cu substrates by imposing *** cu_(6)Sn_(5)grains on(001)cu grew along their c-axis parallel to the substrate and finally merged into one grain to form a fully IMc joint,while those on(011)cu presented a strong texture and merged into a few dominant cu_(6)Sn_(5)grains showing about 30°angle with the *** merging between neighboring cu_(6)Sn_(5)grain pair was attributed to the rapid grain growth and grain boundary ***,a model was put forward to describe the merging *** different morphology and orientation evolutions of the cu_(6)Sn_(5)grains on single crystal and polycrystal cu substrates were revealed based on crystallographic relationship and cu *** method for controlling the morphology and orientation of cu_(6)Sn_(5)grains is really benefitial to solve the reliability problems caused by anisotropy in 3 D packaging.

关键词： 3D packaging Single crystal cu Temperature gradient Orientation Disregistry Grain boundary migration

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Fossil charcoal from the Middle Jurassic of the Ordos Basin,china and its paleoatmospheric implications

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Geoscience Frontiers 2012年第4期3卷 493-502页

作者： lawrence H. Tanner Xin Wang Alesha c. Morabito Department of Biological Sciences Le Moyne College Syracuse NY 13214 USA State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and Palaeontology Chinese Academy of SciencesNanjing 210008 China

The Yah＇an Formation of the Ordos Basin is a sequence of four members, consisting of si- liciclastic sediments deposited in alluvial, lacustrine and mire settings during the Middle Jurassic. Samples collected from Members Two and Four contain abundant blackened plant material identified through standard analytical techniques as fusain （fossil charcoal）. The occurrence of fusain in fluvial sandstones at multiple horizons in the outcrops, combined with the previously reported high concentra- tion of inertinite in the coals of Member One, indicates that paleowildfire was a common occurrence in the Ordos Basin during Yan＇an deposition. Sedimentary evidence from Yan＇an outcrops suggests that the paleoclimate was seasonal during deposition of Members Two through Four, which may have contributed to the wildfire frequency. The presence of fusain in the Yah＇an Formation indicates that atmospheric oxygen levels were clearly above the minimum required for sustained combustion during the Middle Jurassic. This conclusion contradicts previous geochemical models for paleoatmospheric composition, but supports more recent studies.

关键词： Fusain Paleoatmospheric oxygen Wildfire Ordos Basin Yan'an Formation charcoal

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TAAPP: Tiling Array Analysis Pipeline for Prokaryotes

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Genomics, Proteomics & Bioinformatics 2011年第1期9卷 56-62页

作者： Ranjit Kumar Shane c. Burgess Mark L. lawrence Bindu Nanduri college of Veterinary Medicine Mississippi State University Mississippi 39762 USA Institute for Genomics Biocomputing and Biotechnology Mississippi State University Mississippi 39762 USA Mississippi Agriculture and Forestry Experiment Station Mississippi State University Mississippi 39762 USA

High-density tiling arrays provide closer view of transcription than regular microarrays and can also be used for annotating functional elements in genomes. The identified transcripts usually have a complex overlapping architecture when compared to the existing genome annotation. Therefore, there is a need for customized tiling array data analysis tools. Since most of the initial tiling arrays were conducted in eukaryotes, data analysis methods are well suited for eukaryofic genomes. For using whole-genome tiling arrays to identify previously unknown transcriptional elements like small RNA and antisense RNA in prokaryotes, existing data analysis tools need to be tailored for prokaryotic genome architecture. Furthermore, automation of such custom data analysis workflow is necessary for biologists to apply this powerful platform for knowledge discovery. Here we describe TAAPP, a web-based package that consists of two modules for prokaryotic tiling array data analysis. The transcript generation module works on normalized data to generate transcriptionally active regions （TARs）. The feature extraction and annotation module then maps TARs to existing genome annotation. This module further categorizes the transcription profile into potential novel non-coding RNA, antisense RNA, gene expression and operon structures. The implemented workflow is microarray platform independent and is presented as a web-based service. The web interface is freely available for acedemic use at http：//***/TAAPP-HTML/.

关键词： transcriptomics small RNA operon prokaryotes tiling arrays

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Microstructure and mechanical properties of Ti-6Al-4V-5% hydroxyapatite composite fabricated using electron beam powder bed fusion

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Journal of Materials Science & Technology 2019年第2期35卷 309-321页

作者： césar A.Terrazas lawrence E.Murr Diego Bermudez Edel Arrieta David A.Roberson Ryan B.Wicker W.M.Keck center for 3D Innovation The University of Texas at El PasoEl PasoTX 79968USA Department of Mechanical Engineering The University of Texas at El PasoTX 79968USA Department of Metallurgical Materials and Biomedical EngineeringThe University of Texas at El PasoTX 79968USA

A novel, Ti-6 Al-4 V(Ti64)/Hydroxyapatite(HA at 5% by weight concentration) metal/ceramic composite has been fabricated using electron beam powder bed fusion(EPBF) additive manufacturing(AM): specifically, the commercial electron beam melting(EBM?) process. In addition to solid Ti64 and Ti64/5% HA samples, four different unit cell(model) open-cellular mesh structures for the Ti64/5% HA composite were fabricated having densities ranging from 0.68 to 1.12 g/cm^3, and corresponding Young's moduli ranging from 2.9 to 8.0 GPa, and compressive strengths ranging from ~3 to 11 MPa. The solid Ti64/5%HA composite exhibited an optimal tensile strength of 123 MPa, and elongation of 5.5% in contrast to a maximum compressive strength of 875 MPa. Both the solid composite and mesh samples deformed primarily by brittle deformation, with the mesh samples exhibiting erratic, brittle crushing. Solid, EPBF-fabricated Ti64 samples had a Vickers microindentation hardness of 4.1 GPa while the Ti64/5%HA solid composite exhibited a Vickers microindentation hardness of 6.8 GPa. The lowest density Ti64/5%HA composite mesh strut sections had a Vickers microindentation hardness of 7.1 GPa. Optical metallography(OM) and scanning electron microscopy(SEM) analysis showed the HA dispersoids to be highly segregated along domain or grain boundaries, but homogeneously distributed along alpha(hcp) platelet boundaries within these domains in the Ti64 matrix for both the solid and mesh composites. The alpha platelet width varied from ~5 μm in the EPBF-fabricated Ti64 to ~1.1 m for the Ti64/5%HA mesh strut. The precursor HA powder diameter averaged 5 μm, in contrast to the dispersed HA particle diameters in the Ti64/5%HA composite which averaged 0.5 m. This work highlights the use of EPBF AM as a novel process for fabrication of a true composite structure, consisting of a Ti64 matrix and interspersed and exposed HA domains, which to the authors' knowledge has not been reported before. The results also illu

关键词： Hydroxyapatite (HA) Metal-matrix ceramic composites Open-cellular (mesh) structures Electron-beam powder bed fusion (EPBF) Additive manufacturing (AM) Mechanical properties Microstructure characterization

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Bounded type Siegel disks of finite type maps with few singular values Dedicated to the Memory of Professor Lei Tan

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Science china Mathematics 2018年第12期61卷 2139-2156页

作者： Arnaud chéritat Adam lawrence Epstein cNRS Institut de Mathematiques de ToulouseUniversite Paul SabatierToulouse F-31062France Mathematics Institute University of WarwickCoventry CV47ALUK

Let U be an open subset of the Riemann sphere c. We give sufficient conditions for which a finite type map f : U →c with at most three singular values has a Siegel disk compactly contained in U and whose boundary is a quasicircle containing a unique critical point. The main tool is quasiconformal surgery à la Douady-Ghys-Herman-(S′)wia tek. We also give sufficient conditions for which, instead, ? has not compact closure in U. The main tool is the Schwarzian derivative and area inequalities à la Graczyk-(S′)wia tek.

关键词： Siegel disks quasicircles quasiconformal surgery Schwarzian derivative

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Recent research situation in tin dioxide nanomaterials： synthesis, microstructures, and properties

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Frontiers of Materials Science 2013年第3期7卷 203-226页

作者： Zhi-Wen cHEN chan-Hung SHEK c. M. lawrence WU Joseph K. L. LAI Shanghai Applied Radiation Institute School of Environmental and Chemical Engineering Shanghai University Shanghai 200444 China Department of Physics and Materials Science City University of Hong Kong Tat Chee Avenue Kowloon Tong Hong Kong China

This review article summarizes the new research in solid-state physical chemistry understanding of the microstructure characteristics of semiconductor tin oxide thin films made in the last years in our group. The work mainly focuses on the fabrication technology of semiconductor tin oxides thin films by using pulsed laser deposition （PLD） as well as the application of this technology on new micro- and nanostructured materials. It is an interdisciplinary work that integrates the areas of physics, chemistry and materials science.

关键词： tin dioxide thin film synthesis microstructure nanostructure property

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