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Optimized CUDA Implementation to Improve the Performance of Bundle Adjustment Algorithm on GPUs

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Journal of Software engineering and Applications 2024年第4期17卷 172-201页

作者： Pranay r. Kommera Suresh S. Muknahallipatna John e. McInroy Department of electrical engineering and Computer Science University of Wyoming Laramie Wyoming USA

The 3D reconstruction pipeline uses the Bundle Adjustment algorithm to refine the camera and point parameters. The Bundle Adjustment algorithm is a compute-intensive algorithm, and many researchers have improved its performance by implementing the algorithm on GPUs. In the previous research work, “Improving Accuracy and Computational Burden of Bundle Adjustment Algorithm using GPUs,” the authors demonstrated first the Bundle Adjustment algorithmic performance improvement by reducing the mean square error using an additional radial distorting parameter and explicitly computed analytical derivatives and reducing the computational burden of the Bundle Adjustment algorithm using GPUs. The naïve implementation of the CUDA code, a speedup of 10× for the largest dataset of 13,678 cameras, 4,455,747 points, and 28,975,571 projections was achieved. In this paper, we present the optimization of the Bundle Adjustment algorithm CUDA code on GPUs to achieve higher speedup. We propose a new data memory layout for the parameters in the Bundle Adjustment algorithm, resulting in contiguous memory access. We demonstrate that it improves the memory throughput on the GPUs, thereby improving the overall performance. We also demonstrate an increase in the computational throughput of the algorithm by optimizing the CUDA kernels to utilize the GPU resources effectively. A comparative performance study of explicitly computing an algorithm parameter versus using the Jacobians instead is presented. In the previous work, the Bundle Adjustment algorithm failed to converge for certain datasets due to several block matrices of the cameras in the augmented normal equation, resulting in rank-deficient matrices. In this work, we identify the cameras that cause rank-deficient matrices and preprocess the datasets to ensure the convergence of the BA algorithm. Our optimized CUDA implementation achieves convergence of the Bundle Adjustment algorithm in around 22 seconds for the largest dataset compared

关键词： Scene reconstruction Bundle Adjustment Levenberg-Marquardt Non-Linear Least Squares Memory Throughput Computational Throughput Contiguous Memory Access CUDA Optimization

eco-toxicity and health risk assessment of polycyclic aromatic hydrocarbons in surface sediments of Burullus Lake in egypt

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China Geology 2024年第3期7卷 460-468页

作者： Hanan e Osman Mohamed H e el-Morsy Hazem T Abd el-Hamid Department of Biology Faculty of Applied ScienceUmm Al-Qura UniversityMecca 24382Saudi Arabia Deanship of Scientific research Umm Al-Qura UniversityMakkah 24372Saudi Arabia National Institute of Oceanography and Fisheries(NIOF) Cairo 11865Egypt Botany and Microbiology Department Faculty of ScienceAl-Azhar UniversityCairo 11651Egypt

Polycyclic aromatic hydrocarbons(PAHs)are ubiquitous environmental contaminants of growing concern due to their potential ecological and human health *** study presents a comprehensive assessment of PAHs contamination in the surface sediments of Burullus Lake,a vital and second largest delta lake in *** aim was to evaluate the eco-toxicity and potential health risks associated with the presence of these *** seven sediment samples were collected from various drains in the southern part of Burullus *** extraction method was employed to extract PAHs(16PAHs)from the sediment ***,target compounds were located using *** results showed that samples contained PAHs levels ranging from 0.038×10^(-6)to 0.459×10^(-6),which is considered heavily polluted by the european standard for PAHs ***,there was no apparent source of PAHs in the elKhashah drain or the Brinbal Canal,as HPLC found none of the *** most prevalent compound in sediment samples along the study area was *** diagnostic indices in the present study indicated that the hydrocarbons in the region originated from pyrolytic and man-made sources along the drains of Burullus *** principal component analysis(PCA)and diagnostic ratios revealed that coal combustion and pyrolytic sources were responsible for the PAHs contamination in the surface *** non-carcinogenic risk(HI),which is the product of the HQs for the adult and child populations,respectively,was *** values under 1,therefore,demonstrated that they had no carcinogenic effects on human *** and MeQs in the sediments of Burullus Lake do not have a cancer-causing impact on *** the safety of nearby wildlife,aquatic life,and people,all activities that raise petroleum hydrocarbon levels in Burullus Lake must be adequately regulated and *** to the ecological risk assessment,there is little chance that PAHs will be found

关键词： Polycyclic aromatic hydrocarbons Diagnostic indices Toxicity Delta lake sediment Burullus Lake Human health risk Aquatic ecosystem HPLC Coal combustion

Animal models of hepatitis e infection: Advances and challenges

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Hepatobiliary & Pancreatic Diseases International 2024年第2期23卷 171-180页

作者： Ze Xiang Xiang-Lin He Chuan-Wu Zhu Jia-Jia Yang Lan Huang Chun Jiang Jian Wu Chinese Consortium for the Study of Hepatitis e(CCSHe) Zhejiang University School of Medicine Hangzhou 310030China Department of Infectious Diseases The Fifth People’s Hospital of SuzhouSuzhou 215007China Department of Infection Management The Affiliated Suzhou Hospital of Nanjing Medical UniversitySuzhou Municipal HospitalGusu SchoolNanjing Medical UniversitySuzhou 215008China Department of Clinical Laboratory The Affiliated Suzhou Hospital of Nanjing Medical UniversitySuzhou Municipal HospitalGusu SchoolNanjing Medical UniversitySuzhou 215008China 不详

Hepatitis e virus(HeV)is one of the leading causes of acute viral hepatitis *** most of HeV infections are asymptomatic,some patients will develop the symptoms,especially pregnant women,the elderly,and patients with preexisting liver diseases,who often experience anorexia,nausea,vom-iting,malaise,abdominal pain,and *** infection may become chronic in immunosuppressed *** addition,HeV infection can also cause several extrahepatic *** exists in a wide range of hosts in nature and can be transmitted across ***,animals susceptible to HeV can be used as *** establishment of animal models is of great significance for studying HeV transmission,clinical symptoms,extrahepatic manifestations,and therapeutic strategies,which will help us understand the pathogenesis,prevention,and treatment of hepatitis *** review summarized the animal models of HeV,including pigs,monkeys,rabbits,mice,rats,and other *** each animal species,we provided a concise summary of the HeV genotypes that they can be infected with,the cross-species transmission pathways,as well as their role in studying extrahepatic manifestations,prevention,and treatment of HeV *** advantages and disadvantages of these animal models were also *** review offers new perspectives to enhance the current understanding of the research landscape surrounding HeV animal models.

关键词： Hepatitis e virus Animal models Pathogenesis Prevention Treatment

Jigsaw-Sketch: a fast and accurate algorithm for finding top-k elephant flows in high-speed networks

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Science China(Information Sciences) 2024年第4期67卷 113-130页

作者： Boyu ZHANG He HUANG Yu-e SUN Yang DU Dan WANG School of Computer Science and Technology Soochow University School of rail Transportation Soochow University

Finding top-k elephant flows in high-speed networks is one of the most fundamental network measurement tasks. It is more challenging than per-flow size estimation since the IDs and sizes of top-k flows must be tracked simultaneously. Most existing studies only record the IDs of a small number of elephant flows to fit their estimators in the extremely limited high-speed on-chip memory. However, these solutions need too many memory accesses when a packet arrives to track the elephant flows with high accuracy, which limits their practicability. Therefore, this paper proposes Jigsaw-Sketch, a new algorithm to find the top-k elephant flows with much fewer memory accesses while achieving high memory efficiency and accuracy. In this design, we propose a novel two-stage jigsaw storage scheme, which can capture the candidate top-k flows from massive network steams efficiently, and further find the top-k elephant flows with high memory efficiency and only a few memory accesses for each packet. extensive experimental results based on real network traces show that Jigsaw-Sketch improves the packet processing throughput by at least 86%, while achieving smaller memory footprints and higher accuracy compared to the SOTA.

关键词： sketch top-$k$ network measurement elephant flow high-speed networks

Mitochondrial recruitment in myelin:an anchor for myelin dynamics and plasticity?

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Neural regeneration research 2024年第7期19卷 1401-1402页

作者： Jean-David M.Gothié Timothy e.Kennedy Department of Neurology and Neurosurgery Montreal Neurological InstituteMcGill UniversityMontrealQCCanada

Optimal propagation of neuronal electrical impulses depends on the insulation of axons by myelin,produced in the central nervous system by *** is an extension of the oligodendrocyte plasma membrane,which wraps around an axon to form a compact multi-layered *** is composed of a substantially higher proportion of lipids compared to other biological membranes and enriched in a small number of specialized proteins.

关键词： plasticity insulation dynamics

New insights into the role of the endoplasmic reticulum in microglia

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Neural regeneration research 2024年第7期19卷 1397-1398页

作者： Veronika e.Neubrand M.rosario Sepúlveda Department of Cell Biology Faculty of SciencesUniversity of GranadaGranadaSpain

Microglial cells are the only resident immune cells in the central nervous system and constitute its frontline *** are extremely reactive against infections,trauma,or toxins,but are also responsible for mediating inflammation,taking part in the pathogenic course of many neuropathologies(Sierra et al.,2019).Cell-specific staining,ultrastructural analysis by transmission electron microscopy(TeM),or two-photonmicroscopy imaging have been relevant for the characterization of microglia as well as their cell-cell interactions。

关键词： inflammation reticulum

Translating Difference:reflections on the Interface between Novelistic Discourse and World Literature

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Journal of Foreign Languages and Cultures 2024年第1期8卷 16-30页

作者： e.V.rAMAKrISHNAN Central University of Gujarat

The present essay examines two moments from the evolution of the modern Malayalam novel,in relation to the reception of two classics in world literature,namely Victor Hugo's Les Miserables translated into Malayalam between 1925 and 1927 and Garcia Marquez's One Hundred Years of Solitude translated in *** translation of Hugo's novel energized the scene of Malayalam fiction by infusing new modes of representation and widening the intellectual horizons of writers in general,and novelists in *** echoes of Les Miserables could be heard in Malayalam fiction well into the *** struggles against colonial and feudal authorities in Kerala,provided a fertile context for the imaginative interpretation of Hugo's humanist *** paper illustrates this point through close readings of critical essays,autobiographical narratives and debates on the nature of *** fascination of Malayali readers with Garcia Marquez has resulted in the translation of his entire corpus into *** realism as pioneered by Garcia Marquez liberated the Malayalam novelistic narrative from social realist and modernist *** colonial disruption of oral narratives,the consequent cultural amnesia and the struggle to reclaim one's forgotten past are themes that struck a chord in Malayalam writers of *** a detailed discussion of the novel,Moustache by ***,the interface between novelistic discourse and world literature is mapped in the latter part of the essay.

关键词： Malayalam literature translation difference world literature magic realism caste resistance

enhanced quantum resources via two distant atom-cavity systems under the influence of atomic dissipation

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Communications in Theoretical Physics 2024年第2期76卷 62-73页

作者： M Setodeh Kheirabady M K Tavassoly M rafeie e Ghasemian Laser and Optics Group Faculty of PhysicsYazd UniversityYazd 89195-741Iran Department of electrical engineering Faculty of Intelligent Systems Engineering and Data SciencePersian Gulf UniversityBushehrIran

Quantum resources such as entanglement and coherence are the holy grail for modern quantum technologies. Although the unwanted environmental effects tackle quantum information processing tasks, suprisingly these key quantum resources may be protected and even enhanced by the implementation of some special hybrid open quantum systems. Here, we aim to show how a dissipative atom-cavity-system can be accomplished to generate enhanced quantum *** do so, we consider a couple of dissipative cavities, where each one contains two effective two-level atoms interacting with a single-mode cavity field. In practical applications, a classical laser field may be applied to drive each atomic subsystem. After driving the system, a Bell-state measurement is performed on the output of the system to quantify the entanglement and coherence. The obtained results reveal that the remote entanglement and coherence between the atoms existing inside the two distant cavities are not only enhanced, but can be stabilized, even under the action of dissipation. In contrast, the local entanglement between two atoms inside each dissipative cavity attenuates due to the presence of unwanted environmental ***, the local coherence may show the same behavior as the remote ***, the system provides the steady state entanglement in various interaction regimes,particularly in the strong atom-cavity coupling and with relatively large detuning. More interestingly, our numerical analyses demonstrate that the system may show a memory effect due to the fact that the death and revival of the entanglement take place during the interaction. Our proposed model may find potential applications for the implementation of long distance quantum networks. In particular, it facilitates the distribution of quantum resources between the nodes of large-scale quantum networks for secure communication.

关键词： remote entanglement and coherence atomic dissipation steady state entanglement Bell-statemeasurement

Brain dysfunctions and neurotoxicity induced by psychostimulants in experimental models and humans:an overview of recent findings

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Neural regeneration research 2024年第9期19卷 1908-1918页

作者： Marcello Serra Nicola Simola Alexia e.Pollack Giulia Costa Department of Biomedical Sciences Section of NeuroscienceUniversity of CagliariCagliariItaly Department of Biology University of Massachusetts-BostonBostonMAUSA

Preclinical and clinical studies indicate that psychostimulants,in addition to having abuse potential,may elicit brain dysfunctions and/or neurotoxic *** toxicity induced by psychostimulants may pose serious health risks since the recreational use of these substances is on the rise among young people and *** present review provides an overview of recent research,conducted between 2018 and 2023,focusing on brain dysfunctions and neurotoxic effects elicited in experimental models and humans by amphetamine,cocaine,methamphetamine,3,4-methylenedioxymethamphetamine,methylphenidate,caffeine,and *** elucidation of factors and mechanisms that underlie psychostimulant-induced brain dysfunction and neurotoxicity is crucial for understanding the acute and enduring noxious brain effects that may occur in individuals who use psychostimulants for recreational and/or therapeutic purposes.

关键词： 3,4-methylenedioxymethamphetamine amphetamine caffeine cell cultures cocaine methamphetamine methylphenidate neurotoxicity nicotine