3,140 research outputs found

    3D Multiple Object Tracking on Autonomous Driving: A Literature Review

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    3D multi-object tracking (3D MOT) stands as a pivotal domain within autonomous driving, experiencing a surge in scholarly interest and commercial promise over recent years. Despite its paramount significance, 3D MOT confronts a myriad of formidable challenges, encompassing abrupt alterations in object appearances, pervasive occlusion, the presence of diminutive targets, data sparsity, missed detections, and the unpredictable initiation and termination of object motion trajectories. Countless methodologies have emerged to grapple with these issues, yet 3D MOT endures as a formidable problem that warrants further exploration. This paper undertakes a comprehensive examination, assessment, and synthesis of the research landscape in this domain, remaining attuned to the latest developments in 3D MOT while suggesting prospective avenues for future investigation. Our exploration commences with a systematic exposition of key facets of 3D MOT and its associated domains, including problem delineation, classification, methodological approaches, fundamental principles, and empirical investigations. Subsequently, we categorize these methodologies into distinct groups, dissecting each group meticulously with regard to its challenges, underlying rationale, progress, merits, and demerits. Furthermore, we present a concise recapitulation of experimental metrics and offer an overview of prevalent datasets, facilitating a quantitative comparison for a more intuitive assessment. Lastly, our deliberations culminate in a discussion of the prevailing research landscape, highlighting extant challenges and charting possible directions for 3D MOT research. We present a structured and lucid road-map to guide forthcoming endeavors in this field.Comment: 24 pages, 6 figures, 2 table

    Detecting differences across multiple instances of code clones

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    Clone detectors find similar code fragments (i.e., instances of code clones) and report large numbers of them for industrial systems. To maintain or manage code clones, developers often have to in-vestigate differences of multiple cloned code fragments. However, existing program differencing techniques compare only two code fragments at a time. Developers then have to manually combine several pairwise differencing results. In this paper, we present an approach to automatically detecting differences across multiple clone instances. We have implemented our approach as an Eclipse plugin and evaluated its accuracy with three Java software systems. Our evaluation shows that our algorithm has precision over 97.66% and recall over 95.63 % in three open source Java projects. We also conducted a user study of 18 developers to evaluate the use-fulness of our approach for eight clone-related refactoring tasks. Our study shows that our approach can significantly improve de-velopers ’ performance in refactoring decisions, refactoring details, and task completion time on clone-related refactoring tasks. Au-tomatically detecting differences across multiple clone instances also opens opportunities for building practical applications of code clones in software maintenance, such as auto-generation of appli-cation skeleton, intelligent simultaneous code editing

    Yak and Tibet sheep grazing ingestion restrain seed germination of two Saussurea species in Tibetan meadow

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    Grazing disturbance had been defined as an important mechanism that allows the maintenance of species diversities in plant communities. To help understand effect of grazing on seed germination characteristics, we conducted a laboratory germination experiment with two Saussurea species, which were dominant species in alpine meadow communities of the Qinghai-Tibetan Plateau, and yak and Tibet sheep rumen juices. Results showed that yak rumen juices completely restrained seed germination for two species. Tibet sheep rumen juices significantly decreased seed germination percentage, germination index and weighted germination index, prolonged first germination time and mean germination time for two species. Saussurea japonica showed a significantly higher germination percentage, germination index and weighted germination index, but a significantly shorter first germination time and mean germination time than Saussurea iodostegia. Our study suggests that yak and Tibet sheep grazing ingestion may affect species population dynamic by significantly restraining seed germination in alpine area of the Qinghai-Tibetan Plateau.Key words: Rumen juices, seed germination, Saussurea iodostegia, Saussurea japonica

    AT2R (Angiotensin II Type 2 Receptor)-Mediated Regulation of NCC (Na-Cl Cotransporter) and Renal K Excretion Depends on the K Channel, Kir4.1

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    AT2R (AngII [angiotensin II] type 2 receptor) is expressed in the distal nephrons. The aim of the present study is to examine whether AT2R regulates NCC (Na-Cl cotransporter) and Kir4.1 of the distal convoluted tubule. AngII inhibited the basolateral 40 pS K channel (a Kir4.1/5.1 heterotetramer) in the distal convoluted tubule treated with losartan but not with PD123319. AT2R agonist also inhibits the K channel, indicating that AT2R was involved in tonic regulation of Kir4.1. The infusion of PD123319 stimulated the expression of tNCC (total NCC) and pNCC (phosphorylated NCC; Thr(53)) by a time-dependent way with the peak at 4 days. PD123319 treatment (4 days) stimulated the basolateral 40 pS K channel activity, augmented the basolateral K conductance, and increased the negativity of distal convoluted tubule membrane. The stimulation of Kir4.1 was essential for PD123319-induced increase in NCC because inhibiting AT2R increased the expression of tNCC and pNCC only in wild-type but not in the kidney-specific Kir4.1 knockout mice. Renal clearance study showed that thiazide-induced natriuretic effect was larger in PD123319-treated mice for 4 days than untreated mice. However, this effect was absent in kidney-specific Kir4.1 knockout mice which were also Na wasting under basal conditions. Finally, application of AT2R antagonist decreased the renal ability of K excretion and caused hyperkalemia in wild-type but not in kidney-specific Kir4.1 knockout mice. We conclude that AT2R-dependent regulation of NCC requires Kir4.1 in the distal convoluted tubule and that AT2R plays a role in stimulating K excretion by inhibiting Kir4.1 and NCC
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