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Optimization of the Use of Spherical Targets for Point Cloud Registration Using Monte Carlo Simulation

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Journal of Geodesy and Geoinformation Science 2024年第2期7卷 18-36页

作者： CHAN Ting On XIAO Hang XIA Linyuan LICHTI derek D LI Ming Ho DU Guoming School of Geography and Planning Sun Yat-sen UniversityGuangzhou 510275China Guangdong Provincial Key Laboratory of Urbanization and Geo-Simulation Sun Yat-sen UniversityGuangzhou 510275China Guangdong Provincial Engineering Research Center for Public Security and Disasters Sun Yat-sen UniversityGuangzhou 510275China Department of Geomatics Engineering Schulich School of EngineeringUniversity of CalgaryCalgary AB T2N 1N4Canada

Registrations based on the manual placement of spherical targets are still being employed by many professionals in the ***,the placement of those targets usually relies solely on personal experience without scientific evidence supported by numerical *** paper presents a comprehensive investigation,based on Monte Carlo simulation,into determining the optimal number and positions for efficient target placement in typical scenes consisting of a pair of *** demonstrates new check-up statistical rules and geometrical constraints that can effectively extract and analyze massive simulations of unregistered point clouds and their corresponding *** than 6×10^(7) sets of the registrations were simulated,whereas more than IOO registrations with real data were used to verify the results of *** results indicated that using five spherical targets is the best choice for the registration of a large typical registration site consisting of two vertical facades and a ground,when there is only a box set of spherical targets *** a result,the users can avoid placing extra targets to achieve insignificant improvements in registration *** results also suggest that the higher registration accuracy can be obtained when the ratio between the facade-to-target distance and target-to-scanner distance is approximately 3:***,the targets should be placed closer to the scanner rather than in the middle between the facades and the scanner,contradicting to the traditional thought. besides,the results reveal that the accuracy can be increased by setting the largest projected triangular area of the targets to be large.

关键词： point cloud registration Monte Carlo simulation optimalization spherical target

Plant cell wall-mediated disease resistance:Current understanding and future perspectives

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Molecular Plant 2024年第5期17卷 699-724页

作者： Antonio Molina Lucıa Jorda Miguel angel Torres Marina Martın-Dacal Diego Jose berlanga Patricia Fernandez-Calvo Elena Gomez-Rubio Sonsoles Martın-santamarıa Centro de biotecnología y Genómica de Plantas Universidad Politécnica de Madrid(UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria(INIA/CSIC)Campus de Montegancedo UPMPozuelo de Alarcon(Madrid)Spain Departamento de biotecnologıa-biología Vegetal Escuela Técnica Superior de Ingenierıa AgronomicaAlimentarıa y de BiosistemasUPMMadridSpain Centro de Investigaciones biologicas Margarita Salas Consejo Superior de Investigaciones Científicas(CSIC)Ramiro de Maeztu 928040 MadridSpain Misión biológica de Galicia Consejo Superior de Investigaciones Científicas(CSIC)Campus de Montegancedo UPMPozuelo de Alarcón(Madrid)Spain

beyond their function as structural barriers,plant cell walls are essential elements for the adaptation of plants to environmental *** walls are dynamic structures whose composition and integrity can be altered in response to environmental challenges and developmental *** wall changes are perceived by plant sensors/receptors to trigger adaptative responses during development and upon stress *** cell wall damage caused by pathogen infection,wounding,or other stresses leads to the release of wall molecules,such as carbohydrates(glycans),that function as damage-associated molecular patterns(DAMPs).DAMPs are perceived by the extracellular ectodomains(ECDs)of pattern recognition receptors(PRRs)to activate pattern-triggered immunity(PTI)and disease ***,glycans released from the walls and extracellular layers of microorganisms interacting with plants are recognized as microbe-associated molecular patterns(MAMPs)by specific ECD-PRRs triggering PTI *** number of oligosaccharides DAMPs/MAMPs identified that are perceived by plants has increased in recent ***,the structural mechanisms underlying glycan recognition by plant PRRs remain ***,this knowledge is mainly focused on receptors of the LysM-PRR family,which are involved in the perception of various molecules,such as chitooligosaccharides from fungi and lipo-chitooligosaccharides(i.e.,Nod/MYC factors from bacteria and mycorrhiza,respectively)that trigger differential physiological ***,additional families of plant PRRs have recently been implicated in oligosaccharide/polysaccharide *** include receptor kinases(RKs)with leucine-rich repeat and Malectin domains in their ECDs(LRR-MAL RKs),Catharanthus roseus RECEPTOR-LIKE KINASE 1-LIKE group(CrRLK1L)with Malectin-like domains in their ECDs,as well as wall-associated kinases,lectin-RKs,and *** characterization of structural basis of glycans recogniti

关键词： Arabidopsis thaliana cell wall damage-associated molecular patterns DAMPs disease resistance glycans oligosaccharides pattern-triggered immunity PTl pattern recognition receptor PRRs

Shear behavior of ultrafine magnetite tailings subjected to freeze-thaw cycles

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International Journal of Mining Science and Technology 2019年第4期29卷 609-616页

作者： Chong Wei derek b.Apel Yunhai Zhang School of Mining and Petroleum Engineering University of AlbertaEdmontonAlberta T6G 2R3Canada School of Resources and Safety Engineering Central South UniversityChangsha 410083China

To study the shear behavior of the ultrafine magnetite tailings subjected to freeze-thaw cycles,unconsolidated-undrained shear tests were conducted on ultrafine-grained tailings that were subjected to 1-11 cycles of freeze-thaw and defined as a type of clayey silt under confining pressures of 100,200,and 300 *** the number of freeze-thaw cycles,cooling temperature,initial dry density,and moisture content as the four main influencing factors of shear behavior of the tailings samples,the shear stress-strain curve,compression modulus,failure strength,cohesion,and internal friction angle were *** results show that the freeze-thaw cycle has an obvious weakening effect on the shear behavior of the tailings material,and the shear mechanical parameters are affected by a combination of confining pressure,freeze-thaw cycle condition,and initial physical-mechanical properties of the tailings *** the microstructural analysis of the tailings samples subjected to freeze-thaw cycles,it shows that the freeze-thaw cycle mainly affects the porosity,bound water,and arrangement of the tailings ***,the macroscopic changes in shear strength indexes emerge,and then the stability of the tailings dam will decrease.

关键词： Ultrafine magnetite tailings(UMT) Freeze-thaw cycle Shear behavior Triaxial shear test

Performance evaluation of near real-time condition monitoring in haul trucks

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International Journal of Mining Science and Technology 2020年第6期30卷 909-915页

作者： Hemanth Reddy Alla Robert Hall derek b.Apel University of Alberta Edmonton T6G 2H5Canada

Strategic maintenance plays a key role in ensuring high availability and utilization of the haul trucks,and as equipment began to grow more complex towards the end of the 20th century,there was a need for a proactive maintenance strategy,which led to the development of condition-based *** condition monitoring(RTCM)is the ability to perform condition monitoring in real-time and has the ability to alert maintenance and operations of abnormal *** alarms can be used as an indication leading to a problem,and if a suitable corrective action is initiated in time,it could result in significant savings of equipment downtime and repair *** study aims to compare some maintenance performance indicators prior to and after implementation of RTCM strategy at a mine site using some tests of statistical *** study also indicated the presence of seasonality in the data,and thus the data was deseasonalized and detrended prior to being subjected to the statistical ***,the results indicated that RTCM strategy has proven to be successful in improving the availability for some of the failure categories chosen in this study.

关键词： Haul trucks Real-time condition monitoring Performance indicators

Shear properties of cemented rockfills

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Journal of Rock Mechanics and Geotechnical Engineering 2018年第4期10卷 635-644页

作者： bob A.Lingga derek b.Apel Department of Civil and Environmental Engineering School of Mining and Petroleum University of Alberta

Application of cemented rockfilling to underground mining could not be separated from the corresponding backfill’s shear strength properties. The shear of cemented rockfill(CRF)-rock wall and the shear interaction occurring within CRFs both have some disadvantageous failure chances. In this study,we tried to investigate the complete shear properties of CRFs using direct shear and triaxial tests of cemented granite rockfill. Large-scale triaxial testing was held to accommodate the large CRF *** shear testing on the prepared flat and smooth surfaces was assessed with brief conversions and their corrections were used to approximate the shear strength envelopes of CRF joint interfaces. Two types of CRFs with the same aggregate size and distribution but different unconfined compressive strengths(UCSs) due to different mixture designs indicated insignificant differences between their basic friction angles, and also their asperity inclination angles. Nevertheless, investigation between direct shear test and triaxial test showed that the specimen with higher UCS tended to have a slightly lower friction angle but a higher cohesion than the other one.

关键词： Cemented rockfill (CRF) Shear tests Shear strength Friction angle Cohesion backfill interface

Machine learning methods for rockburst prediction-state-of-the-art review

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International Journal of Mining Science and Technology 2019年第4期29卷 565-570页

作者： Yuanyuan Pu derek b.Apel Victor Liu Hani Mitri School of Mining and Petroleum Engineering University of AlbertaEdmonton T6G 2R3Canada Department of Mining and Materials Engineering McGill UniversityMontreal H3A 2T6Canada

One of the most serious mining disasters in underground mines is rockburst *** can lead to injuries and even fatalities as well as damage to underground openings and mining *** has forced many researchers to investigate alternative methods to predict the potential for rockburst ***,due to the highly complex relation between geological,mechanical and geometric parameters of the mining environment,the traditional mechanics-based prediction methods do not always yield precise *** the emergence of machine learning methods,a breakthrough in the prediction of rockburst occurrence has become possible in recent *** paper presents a state-ofthe-art review of various applications of machine learning methods for the prediction of rockburst ***,existing rockburst prediction methods are introduced,and the limitations of such methods are highlighted.A brief overview of typical machine learning methods and their main features as predictive tools is then *** current applications of machine learning models in rockburst prediction are surveyed,with related mechanisms,technical details and performance analysis.

关键词： Rockburst prediction burst liability Artificial neural network Support vector machine Deep learning

Assessment of digital image correlation method in determining large scale cemented rockfill strains

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International Journal of Mining Science and Technology 2019年第5期29卷 771-776页

作者： bob A.Lingga derek b.Apel Mohammadali Sepehri Yuanyuan Pu School of Mining and Petroleum Engineering University of AlbertaEdmonton T6G 2W2Canada

A conventional contact method(using linear transducers)and a non-contact method are deployed to measure the axial and lateral deformations of large scale cylindrical cemented rockfill *** works incorporating two pinhole cameras to create one stereovision by digital image correlation shows that the non-contact method is as reliable for testing large cylindrical specimens as measurements done by using linear variable displacement transformer and string *** this particular large specimen,the experiment resulted in the acceptable mean difference between lateral strain using both methods is 5.1 percent,and 14.5 percent for the axial *** occurrence is inevitable due to the heterogeneity of the concrete system and the placement of the monitoring point in digital image correlation method,although the comparison of stress-strain relationship in both methods still indicates a *** on the results of the present experiments,the authors recommend the noncontact method for a detailed investigation of the material behavior during the uniaxial compressive strength *** field strain measurement enables this digital method to examine local strains near cracks at any point,a very useful tool for studying material deformation behavior.

关键词： Experimental testing Cemented rockfill Digital image correlation Strain measurement Mine backfill

Evaluation of the performance of yielding rockbolts during rockbursts using numerical modeling method

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International Journal of Coal Science & Technology 2022年第6期9卷 25-50页

作者： Jun Wang derek b.Apel Huawei Xu Chong Wei School of Mining and Petroleum Engineering University of AlbertaT6G 2R3 EdmontonABCanada

Rockburst;Rockburst damage;Yielding rockbolt;Numerical modeling;UDEC;Underground miningThe assessment of yielding rockbolt performance during rockbursts with actual seismic loading is essential for rock-burst supporting *** this paper,two types of yielding rockbolts(D-bolt and Roofex)and the fully resin-grouted rebar bolt are modeled via the"rockbolt"element in universal distinct element code(UDEC)after an exact calibration procedure.A two-dimensional(2D)model of a deep tunnel is built to fully evaluate the performance(e.g.,capacity of energy-absorption and control of rock damage)of yielding and traditional rockbolts based on the simulated *** influence of different rockburst magnitudes is also *** results suggest that the D-bolt can effectively control and mitigate rockburst damage during a weak rockburst because of its high strength and deformation *** Roofex is too"soft"or"smooth"to limit the movement of ejected rocks and restrain the large deformation,although it has an excellent deformation *** resin-grouted rebar bolt can maintain a high axial force level during rockbursts but is easy to break during dynamic shocks,which fails to control rapid rock bulking or *** types of rockbolts cannot control the large deformation and mitigate rockburst damage effectively during violent *** rockburst damage severity can be significantly reduced by additional support with cable *** study highlights the effectiveness of numerical modeling methods in assessing the complex performance of yielding rockbolts during rockbursts,which can provide some references to improve and optimize the design of rock supporting in burst-prone grounds.

关键词： Rockburst Rockburst damage Yielding rockbolt Numerical modeling UDEC Underground mining

Erlotinib inhibits progression to dysplasia in a colitis-associated colon cancer model

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World Journal of Gastroenterology 2011年第44期17卷 4858-4866页

作者： beatriz Pagán angel A Isidro Myrella L Cruz Domenico Coppola Caroline b Appleyard Department of Physiology and Pharmacology Ponce School of Medicine Department of Anatomic Pathology H.Lee Moffitt Cancer Center and Research Institute

AIM:To investigate the role of epidermal growth factor receptor(EGFR) in colitis-associated dysplasia using the EGFR tyrosine kinase inhibitor ***:Sprague-Dawley rats received trinitrobenzene sulfonic acid(TNbS;30 mg in 50% ethanol,ic),followed 6 wk later by reactivation with TNbS(5 mg/kg,iv) for 3 *** induce colitis-associated dysplasia,rats then received TNbS(iv) twice a week for 10 *** group received erlotinib(10 mg/kg,ip) for 1 wk before the start of the reactivation of the colitis and 2 wk after(21 d);the rest received the *** rats were euthanized,the colons were removed and analyzed for damage and expression of the EGFR downstream effectors Erk1/2 and ***:Ninety percent of the vehicle-treated animals had dysplasia in any region of the ***-treated animals had a significant decrease in the incidence of dysplasia compared to vehicle-treated animals in all regions of the colon(50.00% ± 11.47% vs 90.00% ± 10.00% in proximal,P b-treated animals also had reduced cell proliferation,reduced active Erk1/2,and reduced c-Myc in colon epithelium compared with the vehicle-treated *** vitro,erlotinib treatment was shown to markedly decrease c-Myc and pErk1/2 levels in rat epithelial *** of rat epithelial cells was stimulated by epidermal growth factor and inhibited by erlotinib(P b can decrease the development of colitis-associated dysplasia,suggesting a potential therapeutic use for erlotinib in patients with long-standing colitis.

关键词： Animal model Epidermal growth factor receptor Colitis Dysplasia Erlotinib