334,446 research outputs found

    Go Beyond Point Pairs: A General and Accurate Sim2Real Object Pose Voting Method with Efficient Online Synthetic Training

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    Object pose estimation is an important topic in 3D vision. Though most current state-of-the-art method that trains on real-world pose annotations achieve good results, the cost of such real-world training data is too high. In this paper, we propose a novel method for sim-to-real pose estimation, which is effective on both instance-level and category-level settings. The proposed method is based on the point-pair voting scheme from CPPF to vote for object centers, orientations, and scales. Unlike naive point pairs, to enrich the context provided by each voting unit, we introduce N-point tuples to fuse features from more than two points. Besides, a novel vote selection module is leveraged in order to discard those `bad' votes. Experiments show that our proposed method greatly advances the performance on both instance-level and category-level scenarios. Our method further narrows the gap between sim-to-real and real-training methods by generating synthetic training data online efficiently, while all previous sim-to-real methods need to generate data offline, because of their complex background synthesizing or photo-realistic rendering. Code repository: https://github.com/qq456cvb/BeyondPPF

    Large-Scale Structure in Brane-Induced Gravity II. Numerical Simulations

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    We use N-body simulations to study the nonlinear structure formation in brane-induced gravity, developing a new method that requires alternate use of Fast Fourier Transforms and relaxation. This enables us to compute the nonlinear matter power spectrum and bispectrum, the halo mass function, and the halo bias. From the simulation results, we confirm the expectations based on analytic arguments that the Vainshtein mechanism does operate as anticipated, with the density power spectrum approaching that of standard gravity within a modified background evolution in the nonlinear regime. The transition is very broad and there is no well defined Vainshtein scale, but roughly this corresponds to k_*~ 2 at redshift z=1 and k_*~ 1 at z=0. We checked that while extrinsic curvature fluctuations go nonlinear, and the dynamics of the brane-bending mode C receives important nonlinear corrections, this mode does get suppressed compared to density perturbations, effectively decoupling from the standard gravity sector. At the same time, there is no violation of the weak field limit for metric perturbations associated with C. We find good agreement between our measurements and the predictions for the nonlinear power spectrum presented in paper I, that rely on a renormalization of the linear spectrum due to nonlinearities in the modified gravity sector. A similar prediction for the mass function shows the right trends. Our simulations also confirm the induced change in the bispectrum configuration dependence predicted in paper I.Comment: 19 pages, 13 figures. v2: corrected typos, added more simulations, better test of predictions in large mass regime. v3: minor changes, published versio

    Diffusion-driven instabilities and emerging spatial patterns in patchy landscapes

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    Spatial variation in population densities across a landscape is a feature of many ecological systems, from self-organised patterns on mussel beds to spatially restricted insect outbreaks. It occurs as a result of environmental variation in abiotic factors and/or biotic factors structuring the spatial distribution of populations. However the ways in which abiotic and biotic factors interact to determine the existence and nature of spatial patterns in population density remain poorly understood. Here we present a new approach to studying this question by analysing a predator–prey patch-model in a heterogenous landscape. We use analytical and numerical methods originally developed for studying nearest- neighbour (juxtacrine) signalling in epithelia to explore whether and under which conditions patterns emerge. We find that abiotic and biotic factors interact to promote pattern formation. In fact, we find a rich and highly complex array of coexisting stable patterns, located within an enormous number of unstable patterns. Our simulation results indicate that many of the stable patterns have appreciable basins of attraction, making them significant in applications. We are able to identify mechanisms for these patterns based on the classical ideas of long-range inhibition and short-range activation, whereby landscape heterogeneity can modulate the spatial scales at which these processes operate to structure the populations

    Tubular Neighborhoods of Nodal Sets and Diophantine Approximation

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    We give upper and lower bounds on the volume of a tubular neighborhood of the nodal set of an eigenfunction of the Laplacian on a real analytic closed Riemannian manifold M. As an application we consider the question of approximating points on M by nodal sets, and explore analogy with approximation by rational numbers.Comment: 22 pages; revised version containing full proof of lower bound; reference added; to appear in Amer. J. Math

    Implementasi Re-design UI/UX Website Fumigasi Untuk Meningkatkan Customer Experience

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    Fumigation website is a website owned by PT. Prana Argentum which is used as a platform for disseminating information related to pest control. However, based on interviews with company owners, there are some drawbacks such as the appearance of the website is not very user friendly, the information provided is difficult to find. This is also supported by the results of the UEQ pre-survey of website users, where the results of the 6 UEQ scale get the "bad" criterion, which means the low usability value of the website. This study aims to determine the suitability of the company's website in improving customer experience. To overcome the display problems on the website, a solution is needed, namely redesigning the UI/UX design using the double diamond methodology and usability testing along with UEQ. The result of this research is a redesign of the UI/UX design by adding new features such as a price quote feature, an appointment feature, and a transaction feature. To improve the customer experience, researchers also pay attention to the use of colors, fonts, language styles, to user-friendly navigation flows. In this study, two types of tests were carried out, namely usability testing with the Maze tools and UEQ testing. The usability testing results obtained a usability score of 87 which can be said to be good in terms of its usability value. Based on the results of the UEQ test, it is known that there is an increase in the mean value on all UEQ scales. It is proved that the highest mean value is on the perspicuity scale of 2.09 points and the lowest value is on the novelty scale with a value of 1.53 points. the results of the UI/UX website design of PT. Prana Argentum Corporation is classified as good, proper, and acceptable to users

    Reversible Random Sequential Adsorption of Dimers on a Triangular Lattice

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    We report on simulations of reversible random sequential adsorption of dimers on three different lattices: a one-dimensional lattice, a two-dimensional triangular lattice, and a two-dimensional triangular lattice with the nearest neighbors excluded. In addition to the adsorption of particles at a rate K+, we allow particles to leave the surface at a rate K-. The results from the one-dimensional lattice model agree with previous results for the continuous parking lot model. In particular, the long-time behavior is dominated by collective events involving two particles. We were able to directly confirm the importance of two-particle events in the simple two-dimensional triangular lattice. For the two-dimensional triangular lattice with the nearest neighbors excluded, the observed dynamics are consistent with this picture. The two-dimensional simulations were motivated by measurements of Ca++ binding to Langmuir monolayers. The two cases were chosen to model the effects of changing pH in the experimental system.Comment: 9 pages, 10 figure
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