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Low-dimensional parametric models are the de-facto standard in computer vision for intrinsic camera calibration. These models explicitly describe the mapping between incoming viewing rays and image pixels. In this paper, we explore an alternative approach which implicitly models the lens distortion. The main idea is to replace the parametric model with a regularization term that ensures the latent
Navigation with terrestrial wireless infrastructure is appealing to overcome geometrical limitations of satellite navigation for users in environments with limited sky views. However, terrestrial signals are also prone to multipath that can result in angular and range estimates that are not representative of actual transmitter-receiver geometry. In this paper, some of these propagation effects are
The performance and reliability of wireless communications at sea are often limited by the deep fades caused by the coherent sea surface reflection. In this paper, we show that by employing multiple antennas at the base station, the deep fades can be mitigated within a large communication range if the antennas are carefully spaced in the vertical direction. We derive a bound for the range where mi
Field-theory simulation by the complex Langevin method offers an alternative to conventional sampling techniques for exploring the forces driving biomolecular liquid–liquid phase separation. Such simulations have recently been used to study several polyampholyte systems. Here, we formulate a field theory corresponding to the hydrophobic/polar (HP) lattice protein model, with finite same-site repul
We prove that polynomial calculus (and hence also Nullstellensatz) over any field requires linear degree to refute that sparse random regular graphs, as well as sparse Erdős-Rényi random graphs, are 3-colourable.
We prove that unary Sherali-Adams requires proofs of size nΩ(d) to rule out the existence of an nΘ(1)-clique in Erdős-Rényi random graphs whose maximum clique is of size d ≤ 2 log n. This lower bound is tight up to the multiplicative constant in the exponent. We obtain this result by introducing a technique inspired by pseudo-calibration which may be of independent interest. The technique involves
Walter Benjamin’s complex notion of time, permeating much of his historical, political, and cultural-critical thought, has been the subject of considerable discussion. In particular, the interaction between the two opposing categories of historical time and messianic time poses a great difficulty: how do messianic moments of cessation act within the homogeneous continuum of history? To propose one
Electromagnetic vector spherical waves have been used recently to model antenna-channel interaction and the available degrees of freedom in multiple-input-multiple-output (MIMO) systems. However, there are no previous accounts of a method to estimate spherical wave coefficients from channel measurements. One approach for this, using a 3-D positioner, is presented and analyzed in this letter. Measu
We study optimal information provision in transportation networks when users are strategic and the network state is uncertain. An omniscient planner observes the network state and discloses information to the users with the goal of minimizing the expected travel time at the user equilibrium. Public signal policies, including full-information disclosure, are known to be inefficient in achieving opt
Software development is a complex activity that needs a lot of tool assistance. Over the years there has been a lot of effort put into development of automated assistance to help with activities such as detection of issues via program analysis, or refactoring of code. Recently, the landscape of developer tool assistance is being disrupted with the entry of AI tools, such as Copilot and ChatGPT, po
The widespread availability of large language models (LLMs) has presented the opportunity for novice programmers to make use of them for the purpose of understanding and synthesising code. In this paper, we discuss a small pilot study intended to explore the user experience of doing so in a limited way, and the attitudes of a group of novice programmers towards this style of programming. We also d
We present novel solutions to previously unsolved prob-lems of relative pose estimation from images whose calibration parameters, namely focal lengths and radial distortion, are unknown. Our approach enables metric reconstruction without modeling these parameters. The minimal case for reconstruction requires 13 points in 4 views for both the calibrated and uncalibrated cameras. We describe and imp
Line segments are ubiquitous in our human-made world and are increasingly used in vision tasks. They are complementary to feature points thanks to their spatial extent and the structural information they provide. Traditional line detectors based on the image gradient are extremely fast and accurate, but lack robustness in noisy images and challenging conditions. Their learned counterparts are more
We present a new SAH guided approach to subdividing triangles as the scene is coarsely partitioned into smaller sets of spatiallycoherent triangles. Our triangle split approach is integrated into the partitioning stage of a fast BVH construction algorithm, butmay as well be used as a stand alone pre-split pass. Our algorithm significantly reduces the number of split triangles comparedto previous m
This paper reports on a case study in which an at- size application is ported onto a commercially available processor array. Its purpose is threefold: (1) Determine the suitability of processor arrays for this kind of application. (2) Develop a runtime software infrastructure that supports streaming applications on processor arrays. (3) Gather data and insights into the resulting system performanc
With the arrival of heterogeneous manycores comprising various features to support task, data and instruction-level parallelism, developing applications that take full advantage of the hardware parallel features has become a major challenge. In this paper, we present an extension to our CAL compilation framework (CAL2Many) that supports data parallelism in the CAL Actor Language. Our compilation f
The problem of joint source-channel coding is considered for a stationary remote (noisy) Gaussian source and a Gaussian channel. The encoder and decoder are assumed to be causal and their combined operations are subject to a delay constraint. It is shown that, under the mean-square error distortion metric, an optimal encoder-decoder pair from the linear and time-invariant (LTI) class can be found
We propose a depth cache that keeps the depth data in compressed format, when possible. Compared to previous work, this requires a more flexible cache implementation, where a tile may occupy a variable number of cache lines depending on whether it can be compressed or not. The advantage of this is that the effective cache size increases proportionally to the compression ratio. We show that the dep
We present a novel architecture for flexible control of shading rates in a GPU pipeline, and demonstrate substantially reduced shading costs for various applications. We decouple shading and visibility by restricting and quantizing shading rates to a finite set of screen-aligned grids, leading to simpler and fewer changes to the GPU pipeline compared to alternative approaches. Our architecture int
