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组织多普勒超声心脏图像的动态三维重建 被引量:2
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作者 何爱军 郑昌琼 +3 位作者 汪天富 李德玉 尹立雪 郑翊 《生物医学工程学杂志》 EI CAS CSCD 北大核心 2005年第3期570-574,共5页
传统的超声心脏图像三维重建技术只限于描述三维及动态三维解剖结构,不能对心脏动态功能做出准确有效的评价。本研究将建立组织多普勒超声心脏图像的动态三维重建方法,通过超声医学图像三维重建技术和组织多普勒超声成像技术的结合,重... 传统的超声心脏图像三维重建技术只限于描述三维及动态三维解剖结构,不能对心脏动态功能做出准确有效的评价。本研究将建立组织多普勒超声心脏图像的动态三维重建方法,通过超声医学图像三维重建技术和组织多普勒超声成像技术的结合,重建心脏运动的动态三维加速度场,为心脏功能的准确评价提供一条新的途径。论文解决了加速度矢量场重建过程中关键的矢量插值和融合显像的问题,从组织多普勒加速度图像中分别重建心肌运动三维加速度场和三维解剖结构,并进行融合显像。试验结果证明了二者之间相对空间位置正确,该方法可以为心脏疾病的诊断和心脏功能的评价提供更多信息,在心脏靶点起搏和心内消融等领域有潜在的应用价值。 展开更多
关键词 组织多普勒超声心脏图像 动态三维重建 心脏疾病 心内消融
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Distribution of Debris Flows in Glacier National Park,Montana,U.S.A. 被引量:2
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作者 WILKERSON Forrest D. +1 位作者 SCHMID Ginger L. 《Journal of Mountain Science》 SCIE CSCD 2008年第4期318-326,共9页
The spectacular scenery of Glacier National Park is the result of glacial erosion as well as post-glacial mass wasting processes. Debris flow magnitude and frequency have been established through extensive fieldwork a... The spectacular scenery of Glacier National Park is the result of glacial erosion as well as post-glacial mass wasting processes. Debris flow magnitude and frequency have been established through extensive fieldwork across seven separate drainage basins in the eastern portion of the park. This paper summarizes the investigation of the hypotheses that debris flow distribution in the Glacier National Park, east of the Continental Divide is (a) not random; and Co) concentrated adjacent to the Continental Divide. The location of 2317 debris flows were identified and mapped from sixty-three 1-m resolution Digital Orthophoto Quarter Quadrangles and their spatial distribution was then analyzed using ArcView Spatial Analyst GIS software. The GIS analysis showed that the debris flows are not randomly distributed nor are they concentrated directly adjacent to the Divide. While the Continental Divide provides orographic enhancement of precipitation directly adjacent to the Divide, the debris flows are not concentrated there due to a lack of available weathered regolith. The most recent Little Ice Age glaciation removed the debris directly adjacent to the Divide, and without an adequate debris supply, these steep slopes experience few debris flows. Both abundant water and an adequate debris supply are necessary to initiate slope failure, resulting in a clustering of debris flows at the break in slope where valley walls contact talus slopes. A variety of summer storm and antecedent moisture conditions initiate slope failures in the Glacier National Park, with no distinct meteorological threshold. With over two million visitorsevery year, and millions of dollars of park infrastructure at risk, identifying the hazard of debris flows is essential to future park management plans. 展开更多
关键词 Debris flows remote sensing GIS GlacierNational Park USA
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Mercury concentrations in blood and feathers of nestling Bald Eagles in coastal and inland Virginia 被引量:2
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作者 David E.Kramar Bill Carstensen +1 位作者 Steve Prisley Jim Campbell 《Avian Research》 CSCD 2019年第1期36-42,共7页
Background:Mercury(Hg) and methylmercury are widely considered significant issues for wildlife,and in particular,piscivorous birds due to their widespread availability and neurotoxic properties.Whereas a substantial n... Background:Mercury(Hg) and methylmercury are widely considered significant issues for wildlife,and in particular,piscivorous birds due to their widespread availability and neurotoxic properties.Whereas a substantial number of studies of Hg contamination of Bald Eagles(Haliaeetus leucocephalus) have been conducted throughout the east coast of the United States,little has been done that directly addresses Hg contamination in Bald Eagles in Virginia,particularly the inland population.Methods:We collected blood and feather samples from nestling Bald Eagles in the coastal plain,piedmont,and western regions of Virginia in an effort to determine which areas of the state were more likely to contain populations showing evidence of Hg toxicity.We analyzed the samples for total Hg using a Milestone DMA-80.Results:Samples collected from individuals located in the coastal region exhibited low concentrations of Hg compared to those further inland located on freshwater rivers and reservoirs.Samples collected from the inland population exhibited levels in some areas that are approaching what may be considered to be sub-lethal to avian health(blood:mean 0.324 mg/kg,SE = 0.13,range = 0.06-0.97 mg/kg;feather:mean = 8.433 mg/kg,SE = 0.3,range = 3.811-21.14 mg/kg).Conclusions:Even after accounting for known point-sources of Hg,the inland eagle population in Virginia is susceptible to concentrations of Hg that are significantly higher than their coastal counterparts.Moreover,several locations besides those currently known to be impacted by point-sources are exhibiting concentrations that are approaching a sub-lethal level. 展开更多
关键词 Bald EAGLE Haliaeetus leucocephalus MERCURY Methyl-mercury VIRGINIA
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Identification of the amino acid involved in the regulation of bacterial pyruvate, orthophosphate dikinase and phosphoenolpyruvate synthetase 被引量:1
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作者 Rebecca Tolentino Chris Chastain Jim Burnell 《Advances in Biological Chemistry》 2013年第3期12-21,共10页
Pyruvate, orthophosphate dikinase (PPDK) and phosphoenolpyruvate synthetase (PEPS) catalyze the conversion of pyruvate to phosphoenolpyruvate (PEP). Both are regulated by a phosphorylation-dephosphorylation mechanism ... Pyruvate, orthophosphate dikinase (PPDK) and phosphoenolpyruvate synthetase (PEPS) catalyze the conversion of pyruvate to phosphoenolpyruvate (PEP). Both are regulated by a phosphorylation-dephosphorylation mechanism involving a bifunctional serine/ threonine kinase and a pyrophosphorylase (PPDK regulatory protein, PDRP, and PEPS regulatory protein, PSRP, respectively). In plants the regulatory mechanism involves phosphorylation of a threonine residue that is separated by a single amino acid from the histidine residue that forms a phosphorylated intermediate during catalysis. Using antibodies, we demonstrated that the regulation of both Listeria monocytogenes PPDK and Escherichia coli PEP synthetase involves the phosphorylation of a threonine residue located close to the catalytic histidine residue. The amino acid located between the regulatory threonine and the catalytic histidine is highly conserved being serine in PPDK and cysteine in PEPS. Using site-directed mutagenesis we have shown that both PPDK and PEPS in which the serine and cysteine residues, respectively, were substituted with an alanine the enzymes could be regulated indicating that the serine and cysteine residues, respectively, are not essential for regulation. We also demonstrated that altering the intermediate amino acid did not alter the specificity of the regulatory proteins for their protein substrates. 展开更多
关键词 Escherichia Coli Listeria MONOCYTOGENES Enzyme REGULATION Phosphoryla-tion/Dephosphorylation PYRUVATE Orthophosphate Dikinase PEP SYNTHETASE
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Combining Agronomic and Pest Studies to Identify Vegetable Soybean Genotypes Suitable for Commercial Edamame Production in the Mid-Atlantic U.S. 被引量:1
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作者 Nick Lord Thomas Kuhar +7 位作者 Steve Rideout Kemper Sutton Adam Alford Xiaoying Li Xingbo Wu Mark Reiter Helene Doughty Bo Zhang 《Agricultural Sciences》 2021年第7期738-754,共17页
Currently, domestic production of vegetable soybean (aka “edamame”) lags well behind consumer demand, with approximately 70% of U.S.-consumed edamame imported each year. A major barrier for growth of the U.S. edamam... Currently, domestic production of vegetable soybean (aka “edamame”) lags well behind consumer demand, with approximately 70% of U.S.-consumed edamame imported each year. A major barrier for growth of the U.S. edamame industry is an overall lack of varieties with adequate consumer acceptability and adaption to the U.S. climate and environment. In this study, we evaluated eleven vegetable soybean genotypes (including one commercial check) for differences in yield, pod size, and resistance to local insect, bacterial, and fungal pressures in order to identify genotypes with the greatest potential for use in commercial edamame production. Although there were variations in average pod length (42.1 - 53.6 mm), width (10.9 - 12.7 mm), and thickness (6.29 - 7.34 mm) among the genotypes, only pod length showed statistical significance. In addition, genotype significantly affected fresh pod yield. The prevalence of specific insect pests varied by location and year and included soybean aphid, potato leafhopper, Mexican bean beetle, as well as a complex of stink bugs and lepidopteran larvae. For each of these insect pests, significant differences were observed. Some plant diseases observed on the edamame genotypes included: downy mildew, bacterial pustule, Fusarium pod rot, Cercospora blight and purple seed stain, and damping off. In 2018, in Whitethorne, VA, soybean downy mildew was quite prevalent and disease symptoms varied considerably. Overall, genotypes V16-0524 and R15-10280 showed particularly favorable yield, and resilience to native pests compared to the commercial check, UA-Kirksey. The genotypes V16-0524 and R15-10280 showed strong potential to increase the availability of varieties that can be used for commercial edamame production in the Mid-Atlantic region. 展开更多
关键词 Edamame GENOTYPES PESTS Agronomics Breeding
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CONVERGENCE OF HYBRID VISCOSITY AND STEEPEST-DESCENT METHODS FOR PSEUDOCONTRACTIVE MAPPINGS AND NONLINEAR HAMMERSTEIN EQUATIONS
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作者 Yekini SHEHU Olaniyi.S.IYIOLA 《Acta Mathematica Scientia》 SCIE CSCD 2018年第2期610-626,共17页
In this article, we first introduce an iterative method based on the hybrid viscos- ity approximation method and the hybrid steepest-descent method for finding a fixed point of a Lipschitz pseudocontractive mapping (... In this article, we first introduce an iterative method based on the hybrid viscos- ity approximation method and the hybrid steepest-descent method for finding a fixed point of a Lipschitz pseudocontractive mapping (assuming existence) and prove that our proposed scheme has strong convergence under some mild conditions imposed on algorithm parameters in real Hilbert spaces. Next, we introduce a new iterative method for a solution of a non- linear integral equation of Hammerstein type and obtain strong convergence in real Hilbert spaces. Our results presented in this article generalize and extend the corresponding results on Lipschitz pseudocontractive mapping and nonlinear integral equation of Hammerstein type reported by some authors recently. We compare our iterative scheme numerically with other iterative scheme for solving non-linear integral equation of Hammerstein type to verify the efficiency and implementation of our new method. 展开更多
关键词 Lipschitz pseudocontractive mapping monotone operators equations of Hammerstein type strong convergence Hilbert spaces
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Surface Macrofabric of Boulder Dominated Desert Mountain Slopes, California, USA
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作者 Donald A. FRIEND 《Journal of Mountain Science》 SCIE CSCD 2005年第3期181-192,共12页
Rhyolite domes formed over a million year continuum in eastern California are used to study boulder dominated slopes. Slopes in this study are steep (-25°to-35°) and are made of coarse boulder sized blocks... Rhyolite domes formed over a million year continuum in eastern California are used to study boulder dominated slopes. Slopes in this study are steep (-25°to-35°) and are made of coarse boulder sized blocks. These slopes include well varnished vertically oriented colluvial deposits that have been likened to relict periglacial stone stripes, or as indicated in this study, are the result of ongoing desert slope processes. The deposits are common throughout the arid southwestern US, but their morphometric character, fabric, and rates of formation have not been assessed systematically. Results indicate that boulder deposits examined here are remnant from the original surface formed during volcanic eruption and that these boulder slope deposits evolve slowly. Grain size, grain shape and grain angularity do not change significantly from genesis to -0.6 Ma; trends in the data change markedly after that time. Mean eigenvectors indicate a fabric oriented downhill, parallel to the slope, consistent with the visual impression that long thin to plate-like rocks orient themselves similarly; however, fabric is actually randomly dispersed, similar to that at slope genesis, as indicated by the eigenvalue analysis resultants of C and K. Interestingly, grainsremain or become more angular over the million-year time scale of the study as they decrease in size, indicating active in situ weathering processes on individual grains; this result is counter to the common assumption that as grains weather they become more rounded over time. 展开更多
关键词 Boulder-fields desert-slopes macrofabric
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A Brief Overview of Amblyaudia
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作者 RaeLynn J. Lamminen Daniel Houlihan 《Health》 2015年第8期927-933,共7页
Amblyaudia, a recent subcategory of auditory processing disorder, is characterized by asymmetrical auditory processing of an individual’s ears. Amblyaudia can result in speech comprehension difficulties, reading diff... Amblyaudia, a recent subcategory of auditory processing disorder, is characterized by asymmetrical auditory processing of an individual’s ears. Amblyaudia can result in speech comprehension difficulties, reading difficulties, information processing deficits, and inattention. These difficulties can be mistakenly attributed to Attention Deficit Hyperactivity Disorder (ADHD), Specific Learning Disorders (SLD), depression, anxiety disorders, and communication disorders. Unfortunately, traditional hearing tests do not place the two ears in competition and cannot detect asymmetry. Therefore, students who exhibit these difficulties and have normal performance on traditional hearing tests should be also evaluated for amblyaudia with dichotic listening tests. Amblyaudia can be addressed through dichotic listening tasks that strengthen the non-dominant ear, as well as minor adjustments to the classroom environment. This paper will examine the current literature on amblyaudia and provide a brief overview of the causes, diagnosis, treatments, and prognosis. 展开更多
关键词 Amblyaudia AUDITORY Processing DISORDER OTITIS MEDIA
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Dietary analysis of Homonota darwini (Squamata:Gekkonidae) in Northern Patagonia
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作者 Marcelo E.KUN Carla PIANTONI +1 位作者 John D.KRENZ Nora R.IBARGüENGOYTíA 《Current Zoology》 SCIE CAS CSCD 北大核心 2010年第4期406-410,共5页
Our study investigated the diet of the southernmost gecko in the world, Homonota darwini. Fifty-three specimens were captured during spring and summer in four locations in Patagonia, Argentina. The stomach contents of... Our study investigated the diet of the southernmost gecko in the world, Homonota darwini. Fifty-three specimens were captured during spring and summer in four locations in Patagonia, Argentina. The stomach contents of the specimens were identified, and we tbund that prey consisted of six main groups: Coleoptera, Hymenoptera, Homoptera and Araneae, and the adults and larvae of moth Lepidoptera. Lepidoptera was the major dietary component. The presence of ants and moths as common prey suggests an ambush feeding strategy. In spring, females consumed more ants than males although no other dietary differences between males and females were evident. We tbund nine geckos with empty stomachs and six parasitized by nematodes. Presence of empty stomachs corroborates previous observations of other nocturnal geckos and non-gecko lizards. Reduced foraging success of nocturnal lizards could be due to difficulty in prey detection due to dim light, reduced or erratic activity of insect prey at night, or shorter activity times of geckos relative to diurnal success. Sex and season were not associated with the incidence of empty stomachs. Principal component analysis showed that four food alternatives correlated with season. The constraint of nocturnality, coupled with low night-time temperatures restricting feeding to only a few hours after sunset, appear to have caused a generality of diet which may limit energy acquisition. We conclude that H. darwini is an arthropod generalist and likely an ambush forager, as are many other nocturnal gekkonids 展开更多
关键词 Nocturnal lizards DIET GEKKONIDAE PATAGONIA PCA
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The Elder Health Information Technology Framework for Geriatric Care in Rural India: A Policy Initiative
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作者 Keya Sen Stan Ingman 《Communications and Network》 2021年第1期12-24,共13页
<span style="font-family:Verdana;">Healthcare monitoring and analysis of healthcare parameters is a reality to reduce costs and increase access to specialist and experts that holds the future for geria... <span style="font-family:Verdana;">Healthcare monitoring and analysis of healthcare parameters is a reality to reduce costs and increase access to specialist and experts that holds the future for geriatric care in India. This paper proposes distinct methods towards the implementation of rural elder health information technologies (IT), which includes electronic medical records, clinical decision support, mobile medical applications, and software driven medical devices used in the diagnosis or treatment of disease for the older adult population in the villages of India. </span><span style="font-family:Verdana;">The purpose is online patient satisfaction at the microlev</span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">el</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> (village pan</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">chayat) through methods accessible and affordable by establishing a common standard of operations at the village primary care units giving way to early disease detection and routine screening among the aged population avoiding institutionalization. The rural elder health IT framework is of great interest for all stakeholders in the field, as it benefits the investors and the consumers, adding to the technological infrastructure, thereby opening new avenues of research in health informatics, telemedicine and enhancing the scope of geriatric research, which in turn enhances the health-related quality of life for the rural older adults in the remote villages of the nation.</span></span></span> 展开更多
关键词 Older Adults Elder Health Information Technology Quality of Life MHEALTH Social Network Interface Service Quality
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Eigenvector Sensitivity: A Kharitonov Result
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作者 Vincent Winstead 《American Journal of Computational Mathematics》 2013年第2期158-168,共11页
This study is motivated by a need to effectively determine the difference between a system fault and normal system operation under parametric uncertainty using eigenstructure analysis. This involves computational robu... This study is motivated by a need to effectively determine the difference between a system fault and normal system operation under parametric uncertainty using eigenstructure analysis. This involves computational robustness of eigenvectors in linear state space systems dependent upon uncertain parameters. The work involves the development of practical algorithms which provide for computable robustness measures on the achievable set of eigenvectors associated with certain state space matrix constructions. To make connections to a class of systems for which eigenvalue and characteristic root robustness are well understood, the work begins by focusing on companion form matrices associated with a polynomial whose coefficients lie in specified intervals. The work uses an extension of the well known theories of Kharitonov that provides computational efficient tests for containment of the roots of the polynomial (and eigenvalues of the companion matrices) in “desirable” regions, such as the left half of the complex plane. 展开更多
关键词 EIGENVECTORS Kharitonov ROBUSTNESS
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Java Parallel Implementations of Kohonen Self-Organizing Feature Maps
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作者 杨尚明 胡洁 《Journal of Electronic Science and Technology of China》 2004年第2期29-35,共7页
The Kohonen self-organizing map (SOM) is an important tool to find a mapping from high-dimensional space to low dimensional space. The time a SOM requires increases with the number of neurons. A parallel implementatio... The Kohonen self-organizing map (SOM) is an important tool to find a mapping from high-dimensional space to low dimensional space. The time a SOM requires increases with the number of neurons. A parallel implementation of the algorithm can make it faster. This paper investigates the most recent parallel algorithms on SOMs. Using Java network programming utilities, improved parallel and distributed system are set up to simulate these algorithms. From the simulations, we conclude that those algorithms form good feature maps. 展开更多
关键词 SOM parallel and distributed system Java network programming
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Partial Collapsing Degeneration of Floer Trajectories and Adiabatic Gluing
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作者 Yong-Geun OH Ke ZHU 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2024年第1期161-249,共89页
In the present paper,we study partial collapsing degeneration of Hamiltonian-perturbed Floer trajectories for an adiabatic ε-family and its reversal adiabatic gluing,as the prototype of the partial collapsing degener... In the present paper,we study partial collapsing degeneration of Hamiltonian-perturbed Floer trajectories for an adiabatic ε-family and its reversal adiabatic gluing,as the prototype of the partial collapsing degeneration of 2-dimensional(perturbed)J-holomorphic maps to 1-dimensional gradient segments.We consider the case when the Floer equations are S^(1)-invariant on parts of their domains whose adiabatic limit has positive length as ε→0,which we call thimble-flow-thimble configurations.The main gluing theorem we prove also applies to the case with Lagrangian boundaries such as in the problem of recovering holomorphic disks out of pearly configuration.In particular,our gluing theorem gives rise to a new direct proof of the chain isomorphism property between the Morse-Bott version of Lagrangian intersection Floer complex of L by Fukaya-Oh-Ohta-Ono and the pearly complex of L Lalonde and Biran-Cornea.It also provides another proof of the present authors’earlier proof of the isomorphism property of the PSS map without involving the target rescaling and the scale-dependent gluing. 展开更多
关键词 Floer trajectory equation partial collapsing degeneration thimble-flow-thimble moduli space adiabatic gluing exponential decay estimates three-interval method
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Error Bounds of Two Smoothing Approximations for Semi-infinite Minimax Problems
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作者 Hong-xia Yin 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 2009年第4期685-696,共12页
In the paper we investigate smoothing method for solving semi-infinite minimax problems. Not like most of the literature in semi-infinite minimax problems which are concerned with the continuous time version(i.e., th... In the paper we investigate smoothing method for solving semi-infinite minimax problems. Not like most of the literature in semi-infinite minimax problems which are concerned with the continuous time version(i.e., the one dimensional semi-infinite minimax problems), the primary focus of this paper is on multi- dimensional semi-infinite minimax problems. The global error bounds of two smoothing approximations for the objective function are given and compared. It is proved that the smoothing approximation given in this paper can provide a better error bound than the existing one in literature. 展开更多
关键词 Semi-infinite minimax problem smoothing method aggregate function error bound polynomial interpolation
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Development of sensing system for 3-dimensional mapping of underground optic fibre cable conduit
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作者 Min Li Sherif Bakr 《Journal of Control and Decision》 EI 2022年第3期265-276,共12页
This paper presents a newly designed sensing system for 3-Dimensional(3D)mapping of underground optic fibre cable conduit with inertial sensors and encoder.This system consists of a sensing unit containing an inertial... This paper presents a newly designed sensing system for 3-Dimensional(3D)mapping of underground optic fibre cable conduit with inertial sensors and encoder.This system consists of a sensing unit containing an inertial measurement unit(IMU)and battery,a duct rodder and a fibre blowing machine with an encoder.A sensor fusion algorithm is developed to estimate the orientation with the measurements of the gyroscope and accelerometer.With the assumption that the sensing unit only moves along one direction,the 3D trajectory or position of the sensing unit is estimated with the encoder readings and orientation estimation.Additional information,such as the orientation and position of the starting and ending points,are integrated into the algorithm to correct the sensing drifting and refine the position estimation.Experiments with three different layouts of the conduits are conducted and analysed graphically and numerically by comparing with the actual layouts。 展开更多
关键词 3D mapping IMU underground conduit sensor fusion
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A distributed-parameter control system using electromagnetic neural stimulation for human-machine perception interface
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作者 Min Li 《Journal of Control and Decision》 EI 2022年第1期23-34,共12页
This article presents a new design of a distributed-parameter control system for human-machine perception interface,which is capable of precisely stimulating the neural systems with electromagnetic fields.By discretis... This article presents a new design of a distributed-parameter control system for human-machine perception interface,which is capable of precisely stimulating the neural systems with electromagnetic fields.By discretising the neural systems,a state-space representation of the electromagnetic stimulation is developed to facilitate the following design and analysis.A forward controller with multiple inputs and multiple outputs is consequently designed to estimate the excitation current.This novel approach enables the applications of the well-established control theory to analyse the system.The feasibility and accuracy of the control system are numerically illustrated and validated with the applications of Transcranial Magnetic Stimulation(TMS)and retinal stimulation.The results indicate that the newly designed control system can not only generate electromagnetic stimulation with better attenuation and focality than the most widely used Figure-8 coil,but also transmit the patterns extracted from images with electromagnetic stimulations to human retinas. 展开更多
关键词 TMS retinal stimulation human-machine interface electromagnetic stimulation distributed-parameter system
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