3D multi-object tracking (MOT) is an essential component for many applications such as autonomous driving and assistive robotics. Recent work on 3D MOT focuses on developing accurate systems giving ...less attention to practical considerations such as computational cost and system complexity. In contrast, this work proposes a simple real-time 3D MOT system. Our system first obtains 3D detections from a LiDAR point cloud. Then, a straightforward combination of a 3D Kalman filter and the Hungarian algorithm is used for state estimation and data association. Additionally, 3D MOT datasets such as KITTI evaluate MOT methods in the 2D space and standardized 3D MOT evaluation tools are missing for a fair comparison of 3D MOT methods. Therefore, we propose a new 3D MOT evaluation tool along with three new metrics to comprehensively evaluate 3D MOT methods. We show that, although our system employs a combination of classical MOT modules, we achieve state-of-the-art 3D MOT performance on two 3D MOT benchmarks (KITTI and nuScenes). Surprisingly, although our system does not use any 2D data as inputs, we achieve competitive performance on the KITTI 2D MOT leaderboard. Our proposed system runs at a rate of 207.4 FPS on the KITTI dataset, achieving the fastest speed among all modern MOT systems. To encourage standardized 3D MOT evaluation, our code is publicly available at http://www.xinshuoweng.com/projects/AB3DMOT.
Recent advances in 3D sensing have created unique challenges for computer vision. One fundamental challenge is finding a good representation for 3D sensor data. Most popular representations (such as ...PointNet) are proposed in the context of processing truly 3D data (e.g. points sampled from mesh models), ignoring the fact that 3D sensored data such as a LiDAR sweep is in fact 2.5D. We argue that representing 2.5D data as collections of (x,y,z) points fundamentally destroys hidden information about freespace. In this paper, we demonstrate such knowledge can be efficiently recovered through 3D raycasting and readily incorporated into batch-based gradient learning. We describe a simple approach to augmenting voxel-based networks with visibility: we add a voxelized visibility map as an additional input stream. In addition, we show that visibility can be combined with two crucial modifications common to state-of-the-art 3D detectors: synthetic data augmentation of virtual objects and temporal aggregation of LiDAR sweeps over multiple time frames. On the NuScenes 3D detection benchmark, we show that, by adding an additional stream for visibility input, we can significantly improve the overall detection accuracy of a state-of-the-art 3D detector.
Today's news media is full of references to 'globalization' - a buzz word that is quickly becoming ubiquitous. But what exactly is globalization? What are its main driving forces? Does it truly ...embrace all aspects of our lives, from economics to cultural developments?
A Globalizing World? examines these and other key questions in a highly accessible fashion, offering a clear and intelligent guide to the big ideas and debates of our time. In doing so, it does not take one particular stance for or against globalizaton; rather, it examines the arguments and evidence about its nature, form and impact.
After introducing the main theoretical positions of those who have studied the subject, key chapters look at the changing form of modern communication and cultural industries, trade patterns and financial flows of the world economy, and whether or not the 'new political world order' is qualitatively different from the old state system. This is essential reading for all students of politics, economics and international relations.
After the devastation of World War II, a new international community was built, organized under the newly formed United Nations which oversaw the development of a new legal and institutional ...framework for the maintenance of peace and security. Maintaining global peace and stability served the purpose of limiting violence, but it was also a prerequisite for accelerating “globalisation”. Even during the years of the Cold War, deep tensions between the United States and the Soviet Union facilitated, paradoxically, a deepening of interdependence and coordination among world powers. The logic of MAD (“mutually assured destruction”) determined the awareness of the shared vulnerability of the globe. From the late 1940s to the beginning of the 21st century, a densely complex and interdependent world order emerged. Global interdependence has now progressed to the point where it is beginning to undermine our ability to engage in further cooperation. The need for international cooperation has never been higher and yet effective institutionalized multilateral cooperation has stalled. It is possible to identify four reasons for this blockage, four pathways to gridlock: rising multipolarity, more difficult problems, institutional inertia and institutional fragmentation. Still, there exists a range of instances in which gridlock has not prevented effective global governance from emerging – some “pathways” out of gridlock. The following article discusses the reasons behind gridlock and the four pathways through and beyond it, in order to identify mechanisms through which effective global change can occur. This task, the search for pathways through and beyond gridlock, is a hugely significant one, if global governance is to be once again effective, responsive and fit for purpose.
This project investigated associational interactions (associational resistance or susceptibility) between native and non-native trees commonly found in urban landscapes in the southeastern United ...States. Non-native plants offer limited ecological services because few native herbivore species are capable of feeding on them. In a 2-yr field study, abundance and species richness of caterpillars, plant damage, and herbivore natural enemies were evaluated in plots where a native red maple (Acer rubrum L. Sapindales: Aceraceae) was planted singly (no neighbors) or interplanted with either non-native non-congeneric crepe myrtles (Lagerstroemia indica L. Myrtales: Lythraceae), non-native congeneric Norway maples (Acer platanoides L. Sapindales: Aceraceae), or other red maples. Dryocampa rubicunda Fabricius (Lepidoptera: Saturniidae) accounted for most of the damage and caterpillar abundance.There were few significant differences between treatment groups in the establishment year of 2014, but in 2015 there was greater tree defoliation, caterpillar abundance, and caterpillar species richness when red maples were surrounded by crepe myrtles. We describe this as a biological fence effect in which the presence of crepe myrtle causes caterpillars to accumulate on the focal red maples over multiple generations. Red maples interplanted with Norway maple neighbors hosted an intermediate abundance and species richness of caterpillars compared to red maples interplanted with crepe myrtles and those with other red maples, indicating a spillover of herbivores to the related maple. No significant trends in insect natural enemy abundance or diversity between treatment groups were detected. These results highlight the necessity of considering plant associational interactions in context of species origin to alleviate pest outbreaks and develop sustainable landscape designs.
Turfgrass culture, a multibillion dollar industry in the United States, poses unique challenges for integrated pest management. Why insect control on lawns, golf courses, and sport fields remains ...insecticide-driven, and how entomological research and extension can best support nascent initiatives in environmental golf and sustainable lawn care are explored. High standards for aesthetics and playability, prevailing business models, risk management–driven control decisions, and difficulty in predicting pest outbreaks fuel present reliance on preventive insecticides. New insights into pest biology, sampling methodology, microbial insecticides, plant resistance, and conservation biological control are reviewed. Those gains, and innovations in reduced-risk insecticides, should make it possible to begin constructing holistic management plans for key turfgrass pests. Nurturing the public's interest in wildlife habitat preservation, including beneficial insects, may be one means to change aesthetic perceptions and gain leeway for implementing integrated pest management practices that lend stability to turfgrass settings.
The use of encapsulated fertilizers and pesticides is a key approach for slowing the release of agrochemicals, while simultaneously reducing costs and environmental problems. The use of hybrid ...systems for encapsulation in organic‐based agriculture, which enables the release of agrochemicals in a single application, has been a growing field. In this approach, a formulation of Bacillus‐thuringiensis as bio‐pesticide and nitrogen, phosphorus, and potassium fertilizer (fish emulsion, potassium nitrate, and potassium phosphate) were formulated using superabsorbent polymers microbeads based on sodium alginate (ALG) then evaluated for release. Different formulations were prepared using 15 wt% of Bt, fish emulsion, nitrogen, and phosphorus. The encapsulated microbeads were prepared by wet‐extrusion processing using sodium alginate as the superabsorbent polymer and calcium chloride as the gelling agent. The resulting beads were characterized in terms of size, morphology, water uptake, and biodegradability. The results showed that the prepared microbeads have narrow size distributions (1.2 to 2.1 mm) and increased water uptake (1,200–3,200%). Moreover, loaded microbeads were analyzed using inductively coupled plasma‐optical emission spectroscopy and Elementar CHNS analyzer to obtain the fertilizer grades as (6.2–0.8–1.05), (0–6.3–6.4), and (0.62–0–2.4) for the one loaded with fish emulsion, for potassium phosphate loaded beads, and for potassium nitrate loaded beads, respectively.
Deformable object manipulation has many applications such as cooking and laundry folding in our daily lives. Manipulating elastoplastic objects such as dough is particularly challenging because dough ...lacks a compact state representation and requires contact-rich interactions. We consider the task of flattening a piece of dough into a specific shape from RGB-D images. While the task is seemingly intuitive for humans, there exist local optima for common approaches such as naive trajectory optimization. We propose a novel trajectory optimizer that optimizes through a differentiable "reset" module, transforming a single-stage, fixed-initialization trajectory into a multistage, multi-initialization trajectory where all stages are optimized jointly. We then train a closed-loop policy on the demonstrations generated by our trajectory optimizer. Our policy receives partial point clouds as input, allowing ease of transfer from simulation to the real world. We show that our policy can perform real-world dough manipulation, flattening a ball of dough into a target shape.
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