solidot此次改版内容包括服务器更新、编程语言、网站后台管理的优化、页面和操作流程的优化等。

## 信息流

• We consider random multimodal $C^3$ maps with negative Schwarzian derivative, defined on a finite union of closed intervals in $[0,1]$, onto the interval $[0,1]$ with the base space $\Omega$ and a base invertible ergodic map $\theta:\Omega\to\Omega$ preserving a probability measure $m$ on $\Omega$. We denote the corresponding skew product map by $T$ and call it a critically finite random map of an interval. We prove that there exists a subset $AA(T)$ of $[0,1]$ with the following properties: (1) For each $t\in AA(T)$ a $t$-conformal random measure $\nu_t$ exists. We denote by $\lambda_{t,\nu_t,\omega}$ the corresponding generalized eigenvalues of the corresponding dual operators $\mathcal{L}_{t,\omega}^*$, $\omega\in\Omega$. (2) Given $t\ge 0$ any two $t$-conformal random measures are equivalent. (3) The expected topological pressure of the parameter $t$: $$\mathcal{E}P(t):=\int_{\Omega}\log\lambda_{t,\nu,\omega}dm(\omega)$$ is independent of the choice of a $t$-conformal random measu

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• Consider the random Cayley graph of a finite, Abelian group $G = \oplus_{j=1}^d \mathbb{Z}_{m_j}$ with respect to $k$ generators chosen uniformly at random. We prove that the simple random walk on this graph exhibits abrupt convergence to equilibrium, known as cutoff, subject to $k \gg 1$, $\log k \ll \log |G|$ and mild conditions on $d$ and $\min_j m_j$ in terms of $|G|$ and $k$. In accordance with spirit of a conjecture of Aldous and Diaconis, the cutoff time is shown to be independent of the algebraic structure of the group; it occurs around the time that the entropy of the simple random walk on $\mathbb{Z}^k$ is $\log|G|$, independent of $d$ and $\{m_j\}_{j=1}^d$. Moreover, we prove a Gaussian profile of convergence to equilibrium inside the cutoff window. We also prove that the order of the spectral gap is $|G|^{-2/k}$ with high probability (as $|G|$ and $k$ diverge); this extends a celebrated result of Alon and Roichman.

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• There is a canonical derived Poisson structure on the universal enveloping algebra $\mathcal{U}\mathfrak{a}$ of a (DG) Lie algebra $\mathfrak{a}$ that is Koszul dual to a cyclic cocommutative (DG) coalgebra. Interesting special cases of this derived Poisson structure include (an analog of) the Chas-Sullivan bracket on string topology. We study how certain derived character of $\mathfrak{a}$ intertwine this derived Poisson structure with the induced Poisson structure on the representation homology of $\mathfrak{a}$. In addition, we obtain an analog of one of our main results for associative algebras.

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• We study the decentralized caching scheme in a two-layer network, which includes a sever, multiple helpers, and multiple users. Basically, the proposed caching scheme consists of two phases, i.e, placement phase and delivery phase. In the placement phase, each helper/user randomly and independently selects contents from the server and stores them into its memory. In the delivery phase, the users request contents from the server, and the server satisfies each user through a helper. Different from the existing caching scheme, the proposed caching scheme takes into account the pre-stored contents at both helpers and users in the placement phase to design the delivery phase. Meanwhile, the proposed caching scheme exploits index coding in the delivery phase and leverages multicast opportunities, even when different users request distinct contents. Besides, we analytically characterize the performance limit of the proposed caching scheme, and show that the achievable rate region of the propo

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• Resonant power converters offer improved levels of efficiency and power density. In order to implement such systems, advanced control techniques are required to take the most of the power converter. In this context, model predictive control arises as a powerful tool that is able to consider nonlinearities and constraints, but it requires the solution of complex optimization problems or strong simplifying assumptions that hinder its application in real situations. Motivated by recent theoretical advances in the field of deep learning, this paper proposes to learn, offline, the optimal control policy defined by a complex model predictive formulation using deep neural networks so that the online use of the learned controller requires only the evaluation of a neural network. The obtained learned controller can be executed very rapidly on embedded hardware. We show the potential of the presented approach on a Hardware-in-the-Loop setup of an FPGA-controlled resonant power converter.

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• A space has $\sigma$-compact tightness if the closures of $\sigma$-compact subsets determines the topology. We consider a dense set variant that we call densely k-separable. We consider the question of whether every densely k-separable space is separable. The somewhat surprising answer is that this property, for compact spaces, implies that every dense set is separable. The path to this result relies on the known connections established between $\pi$-weight and the density of all dense subsets, or more precisely, the cardinal invariant $\delta(X)$.

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• The derived category $D[C,V]$ of the Grothendieck category of enriched functors $[C,V]$, where $V$ is a closed symmetric monoidal Grothendieck category and $C$ is a small $V$-category, is studied. We prove that if the derived category $D(V)$ of $V$ is a compactly generated triangulated category with certain reasonable assumptions on compact generators or $K$-injective resolutions, then the derived category $D[C,V]$ is also compactly generated triangulated. Moreover, an explicit description of these generators is given.

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• Let X be a compact Kahler manifold of dimension n. Let G be a group of zero entropy automorphisms of X. Let G0 be the set of elements in G which are isotopic to the identity. We prove that after replacing G by a suitable finite-index subgroup, G/G0 is a unipotent group of derived length at most n-1. This is a corollary of an optimal upper bound of length involving the Kodaira dimension of X. We also study the algebro-geometric structure of X when it admits a group action with maximal derived length n-1.

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• We study a class of hyperbolic Cauchy problems, associated with linear operators and systems with polynomially bounded coefficients, variable multiplicities and involutive characteristics, globally defined on R^n. We prove well-posedness in Sobolev-Kato spaces, with loss of smoothness and decay at infinity. We also obtain results about propagation of singularities, in terms of wave-front sets describing the evolution of both smoothness and decay singularities of temperate distributions. Moreover, we can prove the existence of random-field solutions for the associated stochastic Cauchy problems. To this aim, we first discuss algebraic properties for iterated integrals of suitable parameter-dependent families of Fourier integral operators, associated with the characteristic roots, which are involved in the construction of the fundamental solution. In particular, we show that, also for this operator class, the involutiveness of the characteristics implies commutative properties for such e

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• A central tool in the study of ergodic random walks on finite groups is the Upper Bound Lemma of Diaconis and Shahshahani. The Upper Bound Lemma uses the representation theory of the group to generate upper bounds for the distance to random and thus can be used to determine convergence rates for ergodic walks. The representation theory of quantum groups is remarkably similar to the representation theory of classical groups. This allows for a generalisation of the Upper Bound Lemma to an Upper Bound Lemma for finite quantum groups. The Upper Bound Lemma is used to study the convergence of ergodic random walks on the dual group $\widehat{S_n}$ as well as on the truly quantum groups of Sekine.

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• This paper gives convex conditions for synthesis of a distributed control system for large-scale networked nonlinear dynamic systems. It is shown that the technique of control contraction metrics (CCMs) can be extended to this problem by utilizing separable metric structures, resulting in controllers that only depend on information from local sensors and communications from immediate neighbours. The conditions given are pointwise linear matrix inequalities, and are necessary and sufficient for linear positive systems and certain monotone nonlinear systems. Distributed synthesis methods for systems on chordal graphs are also proposed based on SDP decompositions. The results are illustrated on a problem of vehicle platooning with heterogeneous vehicles, and a network of nonlinear dynamic systems with over 1000 states that is not feedback linearizable and has an uncontrollable linearization

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• Strong stability preserving (SSP) Runge-Kutta methods are desirable when evolving in time problems that have discontinuities or sharp gradients and require nonlinear non-inner-product stability properties to be satisfied. Unlike the case for L2 linear stability, implicit methods do not significantly alleviate the time-step restriction when the SSP property is needed. For this reason, when handling problems with a linear component that is stiff and a nonlinear component that is not, SSP integrating factor Runge--Kutta methods may offer an attractive alternative to traditional time-stepping methods. The strong stability properties of integrating factor Runge--Kutta methods where the transformed problem is evolved with an explicit SSP Runge--Kutta method with non-decreasing abscissas was recently established. In this work, we consider the use of downwinded spatial operators to preserve the strong stability properties of integrating factor Runge--Kutta methods where the Runge--Kutta method

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• In this paper, dual complex Pell numbers and quaternions are defined. Also, some algebraic properties of dual-complex Pell numbers and quaternions which are connected with dual complex numbers and Pell numbers are investigated. Furthermore, the Honsberger identity, Binet's formula, Cassini's identity, Catalan's identity for these quaternions are given.

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• In this paper, dual-complex k-Pell numbers and dual-complex k-Pell quaternions are defined. Also, some algebraic properties of dual-complex k-Pell numbers and quaternions which are connected with dual-complex numbers and k-Pell numbers are investigated. Furthermore, the Honsberger identity, the d'Ocagne's identity, Binet's formula, Cassini's identity, Catalan's identity for these quaternions are given.

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•   10-11 Hacker News 5608

EU drops rule that would prevent self-driving car data from being copyrighted

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• One-parameter interpolations between any two unitary matrices (e.g., quantum gates) $U_1$ and $U_2$ along efficient paths contained in the unitary group are constructed. Motivated by applications, we propose the continuous unitary path $U(\theta)$ obtained from the QR-factorization $U(\theta)R(\theta)=(1-\theta)A+\theta B,$ where $U_1 R_1=A$ and $U_2 R_2=B$ are the QR-factorizations of $A$ and $B$, and $U(\theta)$ is a unitary for all $\theta$ with $U(0)=U_1$ and $U(1)=U_2$. The QR-algorithm is modified to, instead of $U(\theta)$, output a matrix whose columns are proportional to the corresponding columns of $U(\theta)$ and whose entries are polynomial or rational functions of $\theta$. By an extension of the Berlekamp-Welch algorithm we show that rational functions can be efficiently and exactly interpolated with respect to $\theta$. We then construct probability distributions over unitaries that are arbitrarily close to the Haar measure. Demonstration of computational advantages

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• We give an introduction to the theory and to some applications of eigenvectors of tensors (in other words, invariant one-dimensional subspaces of homogeneous polynomial maps), including a review of some concepts that are useful for their discussion. The intent is to give practitioners an overview of fundamental notions, results and techniques.

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• We review Aomoto's generalized hypergeometric functions on Grassmannian spaces Gr(k +1, n+1). Particularly, we clarify integral representations of the generalized hypergeometric functions in terms of twisted homology and cohomology. With an example of the Gr(2, 4) case, we consider in detail Gauss' original hypergeometric functions in Aomoto's framework. This leads us to present a new systematic description of Gauss' hypergeometric differential equation in a form of a first order Fuchsian differential equation.

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• Given a complete, Ricci-flat 4-manifold with a Killing field, we give an estimate on the manifold's energy in terms of a certain asymptotic quantity of the Killing field. If the Killing field has no zeros and satisfies a certain asymptotic condition, the manifold is flat.

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• It is proved that the projective model structure of the category of topologically enriched diagrams of topological spaces over a topologically enriched locally contractible small category is Quillen equivalent to the standard Quillen model structure of topological spaces. We give a geometric interpretation of this fact in directed homotopy.

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•   10-11 arXiv 5804

Given a countable transitive model of set theory and a partial order contained in it, there is a natural countable Borel equivalence relation on generic objects over the model; two generics are equivalent if they yield the same generic extension. We examine the complexity of this equivalence relations for various partial orders, with particular focus on Cohen and random forcing. We prove, amongst other results, that the former is an increasing union of countably many hyperfinite Borel equivalence relations, while the latter is neither amenable nor treeable.

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• We estimate size of recurrence of an action of a nilpotent group by homeomorphisms of a compact space for polynomial mappings into a nilpotent group form the partial semigroup $(\mathcal{P}_{f}(\mathbb{N}),\uplus)$. To do this we have used algebraic structure of the Stone-\v{C}ech copactification partial semigroup and that of the given nilpotent group.

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• One-dimensional potentials defined by $V^{(S)}(x) =S(S+1) \hbar^2 \pi^2 /[2ma^2\sin^2(\pi x/a)]$ (for integer $S$) arise in the repeated supersymmetrization of the infinite square well, here defined over the region $(0,a)$. We review the derivation of this hierarchy of potentials and then use the methods of supersymmetric quantum mechanics, as well as more familiar textbook techniques, to derive compact closed-form expressions for the normalized solutions, $\psi_n^{(S)}(x)$, for all $V^{(S)}(x)$ in terms of well-known special functions in a pedagogically accessible manner. We also note how the solutions can be obtained as a special case of a family of shape-invariant potentials, the trigonometric P\"oschl-Teller potentials, which can be used to confirm our results. We then suggest additional avenues for research questions related to, and pedagogical applications of, these solutions, including the behavior of the corresponding momentum-space wave functions $\phi_n^{(S)}(p)$ for large $| 收起 • The purpose of this work is to rigorously prove the existence of traveling waves in neural field models with lateral inhibition synaptic coupling types and sigmoidal firing rate functions. In the case of traveling fronts, we utilize theory of linear operators and the implicit function theorem on Banach spaces, providing a variation of the homotopy approach originally proposed by Ermentrout and McLeod (1992) in their seminal study of monotone fronts in neural field models. After establishing the existence of traveling fronts, we move to a well-studied singularly perturbed system with linear feedback. For the special case where the synaptic coupling kernel is a difference of exponential functions, we are able to combine our results for the front with theory of invariant manifolds in autonomous dynamical systems to prove the existence of fast traveling pulses that are comparable to singular homoclinical orbits. Finally, using a numerical approximation scheme, we derive the ubiquitous Evan 收起 • We investigate the algebraic structure of complex Lie groups equipped with left-invariant metrics which are expanding semi-algebraic solitons to the Hermitian curvature flow (HCF). We show that the Lie algebras of such Lie groups decompose in the semidirect product of a reductive Lie subalgebra with their nilradicals. Furthermore, we give a structural result concerning expanding semi-algebraic solitons on complex Lie groups. It turns out that the restriction of the soliton metric to the nilradical is also an expanding algebraic soliton and we explain how to construct expanding solitons on complex Lie groups starting from expanding algebraic solitons on their nirladicals. 收起 • We study the Lie bialgebra structures that can be built on the one-dimensional central extension of the Poincar\'e and (A)dS algebras in (1+1) dimensions. These central extensions admit more than one interpretation, but the simplest one is that they describe the symmetries of (the noncommutative deformation of) an Abelian gauge theory,$U(1)$or$SO(2)$on the (1+1) dimensional Minkowski or (A)dS spacetime. We show that this highlights the possibility that the algebra of functions on the gauge bundle becomes noncommutative. This is a new way in which the Coleman-Mandula theorem could be circumvented by noncommutative structures, and it is related to a mixing of spacetime and gauge symmetry generators when they act on tensor-product states. We obtain all Lie bialgebra structures on centrally-extended Poincar\'e and (A)dS which are coisotropic w.r.t. the Lorentz algebra, and therefore all of them admit the construction of a noncommutative principal gauge bundle on a quantum homogeneous M 收起 • Over an algebraically closed field, various finiteness results are known regarding the automorphism group of a K3 surface and the action of the automorphisms on the Picard lattice. We formulate and prove versions of these results over arbitrary base fields, and give examples illustrating how behaviour can differ from the algebraically closed case. 收起 • In this article we define intersection Floer homology for exact Lagrangian cobordisms between Legendrian submanifolds in the contactisation of a Liouville manifold, provided that the Chekanov-Eliashberg algebras of the negative ends of the cobordisms admit augmentations. From this theory we derive several exact sequences relating the Morse homology of an exact Lagrangian cobordism with the bilinearised contact homologies of its ends. These are then used to investigate the topological properties of exact Lagrangian cobordisms. 收起 • 10-11 arXiv 6001 An infinite cardinal$\lambda$is called Fr\'echet if the Fr\'echet filter on$\lambda$extends to a countably complete ultrafilter. We investigate the relationship between Fr\'echet cardinals and strongly compact cardinals under a hypothesis called the Ultrapower Axiom. 收起 • Error bound condition has recently gained revived interest in optimization. It has been leveraged to derive faster convergence for many popular algorithms, including subgradient methods, proximal gradient method and accelerated proximal gradient method. However, it is still unclear whether the Frank-Wolfe (FW) method can enjoy faster convergence under error bound condition. In this short note, we give an affirmative answer to this question. We show that the FW method (with a line search for the step size) for optimization over a strongly convex set is automatically adaptive to the error bound condition of the problem. In particular, the iteration complexity of FW can be characterized by$O(\max(1/\epsilon^{1-\theta}, \log(1/\epsilon)))$where$\theta\in[0,1]$is a constant that characterizes the error bound condition. Our results imply that if the constrained set is characterized by a strongly convex function and the objective function can achieve a smaller value outside the considered 收起 • We consider stochastic (partial) differential equations appearing as Markovian lifts of affine Volterra processes with jumps from the point of view of the generalized Feller property which was introduced in, e.g., D\"orsek-Teichmann (2010). In particular we provide new existence, uniqueness and approximation results for Markovian lifts of affine rough volatility models of general jump diffusion type. We demonstrate that in this Markovian light the theory of stochastic Volterra processes becomes almost classical. 收起 • We study the one-parameter family of twisted Kahler Taub-NUT metrics (discovered by Donaldson), along with two exceptional Taub-NUT-like instantons, and understand them to the extend that should be sufficient for blow-up and gluing arguments. In particular we parametrize their geodesics from the origin, determine curvature fall-off rates, volume growth rates for metric balls, and find blow-down limits. 收起 • An anonymous reader writes: The Kaiser Family Foundation's annual review of employer-based insurance shows that 21% of large employers collect health information from employees' mobile apps or wearable devices, as part of their wellness programs -- up from 14% last year. Wellness programs are voluntary, and so is contributing your health information to them. But among companies that offer a wellness program, just 9% of employers (including 35% of large employers) offer workers an incentive to participate. 收起 • 10-10 Slashdot 5968 At least two U.S. states are investigating a breach at Alphabet's Google that may have exposed private profile data of at least 500,000 users to hundreds of external developers. From a report: The investigation follows Google's announcement on Monday that it would shut down the consumer version of its social network Google+ and tighten its data-sharing policies after a "bug" potentially exposed user data that included names, email addresses, occupations, genders and ages. "We are aware of public reporting on this matter and are currently undertaking efforts to gain an understanding of the nature and cause of the intrusion, whether sensitive information was exposed, and what steps are being taken or called for to prevent similar intrusions in the future," Jaclyn Severance, a spokeswoman for Connecticut Attorney General George Jepsen, told Reuters in an email. The New York Attorney General's office also said it was looking into the breach. 收起 • 10-10 Hacker News 5890 Boltons: A set of BSD-licensed, pure-Python utilities 收起 • 10-10 Hacker News 5845 Building a speech recognition system for amateur radio communication 收起 • 10-10 Hacker News 5986 Cofactor Genomics (YC S15) Is Hiring a Marketing Specialist in SF 收起 • 10-10 Hacker News 5704 DOD Just Beginning to Grapple with Scale of Weapon Systems Vulnerabilities 收起 • 10-10 THE NEW YORKER 4520 Clare Kayden Hines and Claire Friedman humorously illustrate examples of denim trends for fall. 收起 • 10-10 Hacker News 5172 Flatpak – a security nightmare 收起 • 10-10 Slashdot 6199 Fully self-driving cars may be on the fast lane to U.S. roads under a pilot program the Trump administration said on Tuesday it was considering, which would allow real-world road testing for a limited number of the vehicles. Reuters: Self-driving cars used in the program would potentially need to have technology disabling the vehicle if a sensor fails or barring vehicles from traveling above safe speeds, the National Highway Traffic Safety Administration (NHTSA) said in a document made public Tuesday. NHTSA said it was considering whether it would have to be notified of any accident within 24 hours and was seeking public input on what other data should be disclosed including near misses. The U.S. House of Representatives passed legislation in 2017 to speed the adoption of self-driving cars, but the Senate has not approved it. Several safety groups oppose the bill, which is backed by carmakers. It has only a slender chance of being approved in 2018, congressional aides said. 收起 • An anonymous reader shares a report: Last month, an activist from the German art collective Peng! walked into her local government office in Berlin and applied for a new passport. "I probably have broken the law," the woman, a chemist living in the Western Saxony region, told Motherboard, "but our lawyers don't know which one." The woman applied for a passport using a photo of two separate people. Using specialized software created by Peng!, the collective merged the facial vectors from two different faces from two different images into one. Billie Hoffman (a pseudonym used by everyone in the Peng! Collective when talking to journalists), she told me how easy the whole process was: "Officials didn't mention fraud at any point." Hoffman's passport application was approved, and now she has an official German passport using the digitally altered photo. The photo is half her, half Federica Mogherini, an Italian politician who is the High Representative of the European Union for Foreign Aff 收起 • At its Pixel 3 launch event, Google announced a smart speaker called the Google Home Hub, featuring a 7-inch display to give you visual information, making it easier to control smart home devices and view photos and the weather. Interestingly, Google decided not to include a camera in this device for privacy reasons, as they want you to feel comfortable placing it in an intimate location, such as a bedroom. PhoneDog reports: Google explains that Home Hub will be able to recognize who is speaking to it using Voice Match to provide info for that specific person, which should help to make the device more useful in homes with multiple people. And when you're not using Home Hub, a feature called Live Albums will let you select certain people and have Google Photos create albums with images of these people. Another feature of Google's Home Hub is the Home View. With it, you can easily see and control your smart home devices. And then there's Ambient EQ, which uses a sensor that'll adjust the 收起 • 10-10 OSnews 5815 Not everything got leaked before Google's event today. One surprise announcement that wowed was Call Screen, a new feature that lets the Google Assistant answer your incoming calls and politely ask what the caller wants. A real-time transcript will appear on your screen, allowing you to decide whether or not you want to pick up. When your Pixel rings, a "Screen call" button shows up alongside the usual controls. Tapping it will prompt the Google Assistant to tell your caller that the call is being screened and ask what it's about. Their explanation is transcribed on your screen, and you have options to mark the call as spam or tell the caller you'll get back to them, among others. This is an amazing feature that will save a lot of people a lot of frustration. I want this feature on my phone now. On a related note, Google Duplex, the feature whereby the Google Assistant will call restaurants and such on your behalf, will be rolled out to Pixel phones next month. 收起 • 10-10 Ars Technica 5837 Launching on Pixel 3 family in US, coming to other Pixel phones "next month." 收起 • Alongside the new Pixel smartphones, and the Pixel Slate laptop-tablet hybrid, Google on Tuesday also announced a new version of its Chromecast streaming adapter, the third generation of the company's streaming device, which supports playback video at higher frame rates and can also stream multiroom audio. From a report: The new device goes on sale Tuesday in the U.S., Australia, Canada, Denmark, Finland, Great Britain, Japan, Netherlands, New Zealand, Norway, Singapore and Sweden. Stateside, the new Chromecast once again costs$35 -- the same as its predecessor. [...] The bigger changes are on the inside: The new Chromecast is 15% faster than the previous model, which allows it to stream 1080p HD video with a rate of up to 60 frames per second (fps). "Everything becomes much smoother," said Google Home product manager Chris Chan during a recent interview with Variety. He specifically cited the growth of 60fps content on YouTube as one of the reasons Google added the new feature.

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• Google on Tuesday unveiled the Pixel 3 and Pixel 3 XL, its latest flagship Android smartphones. "For life on the go, we designed the world's best camera and put it in the world's most helpful phone," said Google's hardware chief Rick Osterloh. From a report: The Pixel 3 starts at $799 for 64GB, with the 3 XL costing$899. Add $100 to either for the 128GB storage option. Core specs for both include a Snapdragon 845, 4GB RAM (there's no option for more), Bluetooth 5.0, and front-facing stereo speakers. Also inside is a new Titan M security chip, which Google says provides "on-device protection for login credentials, disk encryption, app data, and the integrity of the operating system." Preorders for both phones begin today, and buyers will get six months of free YouTube Music service. The Pixel 3 and 3 XL both feature larger screens than last year's models thanks to slimmed down bezels -- and the controversial notch in the case of the bigger phone. The 3 XL has a 6.3-inch display (up fro 收起 • 10-10 Slashdot 6131 Google intends to launch a censored version of its Search app for China sometime in the next six to nine months, according to a leaked transcript from a private employee meeting held last month. The Intercept's Ryan Gallagher today reported the company's Search engine chief, Ben Gomes, held a meeting to congratulate a room full of employees working on the platform, dubbed Project Dragonfly. From a report: According to The Intercept, Gomes talked about the launch timeline: "While we are saying it's going to be six and nine months [to launch], the world is a very dynamic place." He goes on to point out that the current political climate makes it difficult to pinpoint a definite timeline, but indicates employees should be ready to launch whenever a "window opens." These comments come in stark contrast to public statements given recently by both Gomes and Google's chief privacy officer, Kieth Enright. Speaking to members of Congress last month, Enright tried to skirt the issue of the Drago 收起 • In addition to announcing new flagship phones today, Google took the wraps off a new premium tablet called the Pixel Slate. It's a Chrome OS-powered slate with a 12.3-inch display that's supposed to be the sharpest in its class. Google claims this isn't just a laptop pretending to be a tablet or a phone pretending to be a computer. From a report: It has a resolution of 3,000 x 2,000 -- i.e., a pixel density of 293 ppi, which Google says is the highest for a premium 12-inch tablet. For reference, the Surface Pro 6 and iPad Pro (12.9 inch) come in at 267 ppi and 264 ppi, respectively. Google was able to make the screen so sharp because of an energy-efficient LCD technology called Low Temperature PolySilicon (LTPS), which let the company pack in more pixels without sacrificing size or battery. In fact, the Pixel Slate is supposed to last up to 12 hours on a charge, which is impressive for its skinny 7mm profile. [...] What stands out about the Pixel Slate is the version of Chrome OS it ru 收起 • 10-10 OSnews 5144 Google unveiled its new Pixel phones today, as well as the Pixel Slate, a ChromeOS tablet/laptop device that's basically a cross between an iPad Pro and a Surface Pro. Virtually everything from the event was leaked over the past few weeks, so there were few - if any - surprises. The new devices are certainly interesting, but Google continues its policy of not making these products available in most of the world, so there's little for me to say about them - I have never seen them, let alone used them. One thing that stood out to me about the Pixel Slate are its specifications - it runs on Intel processors, and in order to get a processor that isn't a slow Celeron or m3, you need to shell out some big bucks. I don't have particularly good experiences with Celeron or m3 processors, and even Intel's mobile i5 chips have never really managed to impress me - hence why I opted for the i7 version of the latest Dell XPS 13 when I bought a new laptop a few weeks ago. In The Verge's video, yo 收起 • 10-10 Slashdot 5890 Google's human-sounding AI software that makes calls for you is coming to Pixel smartphones next month in select markets, like New York, Atlanta, Phoenix, and the San Francisco Bay Area. Google Duplex, as it is called, will be a feature of Google Assistant and, for now, will only be able to call restaurants without online booking systems, which are already supported by the assistant. Wired reports: A Google spokesperson told WIRED that the company now has a policy to always have the bot disclose its true nature when making calls. Duplex still retains the human-like voice and "ums," "ahs," and "umm-hmms" that struck some as spooky, though. Nick Fox, the executive who leads product and design for Google search and the company's assistant, says those interjections are necessary to make Duplex calls shorter and smoother. "The person on the other end shouldn't be thinking about how do I adjust my behavior, I should be able to do what I normally do and the system adapts to that," he says. Fo 收起 • 10-10 MIT Technology 6153 A relation between the precanonical quantization of pure Yang-Mills fields and the functional Schr\"odinger representation in the temporal gauge is discussed. It is shown that the latter can be obtained from the former when the ultraviolet parameter$\varkappa$introduced in precanonical quantization goes to infinity. In this limiting case, the Schr\"odinger wave functional can be expressed as the trace of the Volterra product integral of Clifford-algebra-valued precanonical wave functions restricted to a certain field configuration, and the canonical functional derivative Schr\"odinger equation together with the quantum Gau\ss\ constraint are derived from the Dirac-like precanonical Schr\"odinger equation. 收起 • 10-10 Ars Technica 6048 It bears little resemblance to its 11-inch predecessor from last year. 收起 • 10-10 Ars Technica 5883 Across cultures, the look of pain may be the same—but orgasms have a different face. 收起 • 10-10 Hacker News 5277 How to Get Things Done When You Don't Feel Like It 收起 • 10-10 OSnews 5459 So I learned something new today. Back in the early and mid-90s, IBM tried to build a PC-like platform and ecosystem around its PowerPC processor. They called it the PowerPC Reference Platform, or PReP, and with it, you could build what were effectively PC clones with PowerPC processors, ready to run a number of operating systems, including AIX, Windows NT, OS/2, and Apple's failed Taligent project. None of this is news to me. What is news to me, however, is that aside from a number of desktop PReP machines, IBM also developed and sold a number of PReP laptops under the ThinkPad brand. Sometime in 1994, IBM started working on a prototype mobile system named Woodfield and designated as type 6020. Very little is known about this system; it was never officially announced or sold. On June 19, 1995, IBM announced the ThinkPad 850 and 820 (announcement letters 195-178 and 195-179, respectively) with a planned availability date of July 24, 1995. The ThinkPad 820 designation was typ 收起 • 10-10 Hacker News 5947 In few years renewable power may become a better economic option 收起 • The problems of partially observed major minor LQG and nonlinear mean field game (PO MM LQG MFG) problems where it is assumed the major agent's state is partially observed by each minor agent, and the major agent completely observes its own state have been analysed in the literature. In this paper, PO MM LQG MFG problems with general information patterns are studied where (i) the major agent has partial observations of its own state, and (ii) each minor agent has partial observations of its own state and the major agent's state. The assumption of partial observations by all agents leads to a new situation involving the recursive estimation by each minor agent of the major agent's estimate of its own state. For the general case of indefinite LQG MFG systems, the existence of$\epsilon$-Nash equilibria together with the individual agents' control laws yielding the equilibria are established via the Separation Principle. 收起 • The connection matrix is a powerful algebraic topological tool from Conley index theory that captures relationships between isolated invariant sets. Conley index theory is a topological generalization of Morse theory in which the connection matrix subsumes the role of the Morse boundary operator. Over the last few decades, the ideas of Conley have been cast into a purely computational form. In this paper we introduce a computational, categorical framework for the connection matrix theory. This contribution transforms the computational Conley theory into a computational homological theory for dynamical systems. More specifically, within this paper we have two goals: 1) We cast the connection matrix theory into appropriate categorical, homotopy-theoretic language. We identify objects of the appropriate categories which correspond to connection matrices and may be computed within the computational Conley theory paradigm by using the technique of reductions. 2) We describe an algorithm for 收起 • Traditionally, there are several polynomial algorithms for linear programming including the ellipsoid method, the interior point method and other variants. Recently, Chubanov [Chubanov, 2015] proposed a projection and rescaling algorithm, which has become a potentially \emph{practical} class of polynomial algorithms for linear feasibility problems and also for the general linear programming. However, the Chubanov-type algorithms usually perform much better on the infeasible instances than on the feasible instances in practice. To explain this phenomenon, we derive a new theoretical complexity bound for the infeasible instances based on the condition number, which shows that algorithms can indeed run much faster on infeasible instances in certain situations. In order to speed up the feasible instances, we propose a \emph{Polynomial-time Primal-Dual Projection} algorithm (called PPDP) by explicitly developing the dual algorithm. The numerical results validate that our PPDP algorithm achi 收起 • We consider solving the surface Helmholtz equation on a smooth two dimensional surface embedded into a three dimensional space meshed with tetrahedra. The mesh does not respect the surface and thus the surface cuts through the elements. We consider a Galerkin method based on using the restrictions of continuous piecewise linears defined on the tetrahedra to the surface as trial and test functions.Using a stabilized method combining Galerkin least squares stabilization and a penalty on the gradient jumps we obtain stability of the discrete formulation under the condition$h k < C$, where$h$denotes the mesh size,$k$the wave number and$C$a constant depending mainly on the surface curvature$\kappa$, but not on the surface/mesh intersection. Optimal error estimates in the$H^1$and$L^2$-norms follow. 收起 • The stable center conjecture asserts that the space of stable distributions in the Bernstein center of a reductive p-adic is closed under convolution. It is closely related to the notion of an L-packet and endoscopy theory. We describe a categorical approach to the depth zero part of the conjecture. As an illustration of our method, we show that the Bernstein projector to the depth zero spectrum is stable. 收起 • We study a categorical construction called the cobordism category, which associates to each Waldhausen category a simplicial category of cospans. We prove that this construction is homotopy equivalent to Waldhausen's$S_{\bullet}$-construction and therefore it defines a model for Waldhausen$K$-theory. As an example, we discuss this model for$A$-theory and show that the cobordism category of homotopy finite spaces has the homotopy type of Waldhausen's$A(*)$. We also review the canonical map from the cobordism category of manifolds to$A$-theory from this viewpoint. 收起 • There is a gap in the proof of the main theorem in the article [ShCh13a] on optimal bounds for the Morse lemma in Gromov-hyperbolic spaces. We correct this gap, showing that the main theorem of [ShCh13a] is correct. We also describe a computer certification of this result. 收起 • It has been discovered that linear codes may be described by binomial ideals. This makes it possible to study linear codes by commutative algebra and algebraic geometry methods. In this paper, we give a decoding algorithm for binary linear codes by utilizing the Groebner bases of the associated ideals. 收起 • In this note, we establish an expression of the Loewner energy of a Jordan curve on the Riemann sphere in terms of Werner's measure on simple loops of SLE$_{8/3}$type. The proof is based on a formula for the change of the Loewner energy under a conformal map that is reminiscent of the restriction properties derived for SLE processes. 收起 • We design and analyze solution techniques for a linear-quadratic optimal control problem involving the integral fractional Laplacian. We derive existence and uniqueness results, first order optimality conditions, and regularity estimates for the optimal variables. We propose two strategies to discretize the fractional optimal control problem: a semidiscrete approach where the control is not discretized - the so-called variational discretization approach - and a fully discrete approach where the control variable is discretized with piecewise constant functions. Both schemes rely on the discretization of the state equation with the finite element space of continuous piecewise polynomials of degree one. We derive a priori error estimates for both solution techniques. We illustrate the theory with two-dimensional numerical tests. 收起 • We analyse features of the patterns formed from a simple model for a martensitic phase transition. This is a fragmentation model that can be encoded by a general branching random walk. An important quantity is the distribution of the lengths of the interfaces in the pattern and we establish limit theorems for some of the asymptotics of the interface profile. We are also able to use a general branching process to show almost sure power law decay of the number of interfaces of at least a certain size. We discuss the numerical aspects of determining the behaviour of the density profile and power laws from simulations of the model. 收起 • The Weinstein operator has several applications in pure and applied Mathematics especially in Fluid Mechanics and satisfies some uncertainty principles similar to the Euclidean Fourier transform. The aim of this paper is establish a generalization of uncertainty principles for Weinstein transform in$L_\alpha^p$-norm. Firstly, we extend the Heisenberg-Pauli-Weyl uncertainty principle to more general case. Then we establish three continuous uncertainty principles of concentration type. The first and the second uncertainty principles are$L_\alpha^p$versions and depend on the sets of concentration$\Omega$and$\Sigma$, and on the time function$\varphi$. However, the third uncertainty principle is also$L_\alpha^p$version depends on the sets of concentration and he is independent on the band limited function$\varphi$. These$L_\alpha^p$-Donoho-Stark-type inequalities generalize the results obtained in the case$p=q=2$. 收起 • We describe main issues and design principles of an efficient implementation, tailored to recent generations of Nvidia Graphics Processing Units (GPUs), of an Algebraic Multigrid (AMG) preconditioner previously proposed by one of the authors and already available in the open-source package BootCMatch: Bootstrap algebraic multigrid based on Compatible weighted Matching for standard CPU. The AMG method relies on a new approach for coarsening sparse symmetric positive definite (spd) matrices, named "coarsening based on compatible weighted matching". It exploits maximum weight matching in the adjacency graph of the sparse matrix, driven by the principle of compatible relaxation, providing a suitable aggregation of unknowns which goes beyond the limits of the usual heuristics applied in the current methods. We adopt an approximate solution of the maximum weight matching problem, based on a recently proposed parallel algorithm, referred as the Suitor algorithm, and show that it allow us to o 收起 • A path (cycle) in a$c$-edge-colored multigraph is alternating if no two consecutive edges have the same color. The problem of determining the existence of alternating Hamiltonian paths and cycles in$2$-edge-colored multigraphs is an$\mathcal{NP}$-complete problem and it has been studied by several authors. In Bang-Jensen and Gutin's book "Digraphs: Theory, Algorithms and Applications", it is devoted one chapter to survey the last results on this topic. Most results on the existence of alternating Hamiltonian paths and cycles concern on complete and bipartite complete multigraphs and a few ones on multigraphs with high monochromatic degrees or regular monochromatic subgraphs. In this work, we use a different approach imposing local conditions on the multigraphs and it is worthwhile to notice that the class of multigraphs we deal with is much larger than, and includes, complete multigraphs, and we provide a full characterization of this class. Given a$2$-edge-colored multigraph$G$, 收起 • We use Brascamp-Lieb's inequality to obtain new decoupling inequalities for general Gaussian vectors, and for stationary cyclic Gaussian processes. In the second case, we use a version by Bump and Diaconis of the strong Szego limit theorem. This extends results of Klein, Landau and Shucker. 收起 • Let$(X,{\mathcal A},\mu)$be a probability space and let$S\colon X\to X$be a measurable transformation. Motivated by the paper of K. Nikodem [Czechoslovak Math. J. 41(116) (4) (1991) 565--569], we concentrate on a functional equation generating measures that are absolutely continuous with respect to$\mu$and$\varepsilon$-invariant under$S$. As a consequence of the investigation, we obtain a result on the existence and uniqueness of solutions$\varphi\in L^1([0,1])$of the functional equation $$\varphi(x)=\sum_{n=1}^{N}|f_n'(x)|\varphi(f_n(x))+g(x),$$ where$g\in L^1([0,1])$and$f_1,\ldots,f_N\colon[0,1]\to[0,1]$are functions satisfying some extra conditions. 收起 • Let$p\equiv 4,7\mod 9$be a rational prime number such that$3\mod p$is not a cubic residue. In this paper we prove the 3-part of the product of the full BSD conjectures for$E_p$and$E_{3p^3}$is true using an explicit Gross-Zagier formula, where$E_p: x^3+y^3=p$and$E_{3p^2}: x^3+y^3=3p^2$are the elliptic curves related to the Sylvester conjecture and cube sum problems. 收起 • In this paper we obtain a very general Gauss-Green formula for weakly differentiable functions and sets of finite perimeter. This result is obtained by revisiting Anzellotti's pairing theory and by characterizing the measure pairing$(\boldsymbol{A}, Du)$when$\boldsymbol{A}$is a bounded divergence measure vector field and$u$is a bounded function of bounded variation. 收起 • Given an open subset$\Omega$of a Banach space and a Lipschitz function$u_0: \overline{\Omega} \to \mathbb{R},$we study whether it is possible to approximate$u_0$uniformly on$\Omega$by$C^k$-smooth Lipschitz functions which coincide with$u_0$on the boundary$\partial \Omega$of$\Omega$and have the same Lipschitz constant as$u_0.$As a consequence, we show that every$1$-Lipschitz function$u_0: \overline{\Omega} \to \mathbb{R},$defined on the closure$\overline{\Omega}$of an open subset$\Omega$of a finite dimensional normed space of dimension$n \geq 2$, and such that the Lipschitz constant of the restriction of$u_0$to the boundary of$\Omega$is less than$1$, can be uniformly approximated by differentiable$1$-Lipschitz functions$w$which coincide with$u_0$on$\partial \Omega$and satisfy the equation$\| D w\|_* =1$almost everywhere on$\Omega.$This result does not hold in general without assumption on the restriction of$u_0$to the boundary of$\Omega$. 收起 • We prove, using variational methods, the existence in dimension two of positive vector ground states solutions for the Bose-Einstein type systems $$\begin{cases} -\Delta u+\lambda_1u=\mu_1u(e^{u^2}-1)+\beta v\left(e^{uv}-1\right) \text{ in } \Omega, &\\ -\Delta v+\lambda_2v=\mu_2v(e^{v^2}-1)+\beta u\left(e^{uv}-1\right)\text{ in } \Omega, &\\ u,v\in H^1_0(\Omega) \end{cases}$$ where$\Omega$is a bounded smooth domain,$\lambda_1,\lambda_2>-\Lambda_1$(the first eigenvalue of$(-\Delta,H^1_0(\Omega))$,$\mu_1,\mu_2>0$and$\beta$is either positive (small or large) or negative (small). The nonlinear interaction between two Bose fluids is assumed to be of critical exponential type in the sense of J. Moser. For `small' solutions the system is asymptotically equivalent to the corresponding one in higher dimensions with power-like nonlinearities. 收起 • We review the notion of nuclear dimension for C*-algebras introduced by Winter and Zacharias. We explain why it is a non-commutative version of topological dimension. After presenting several examples, we give a brief overview of the state of the art. 收起 • We consider the problem of private linear computation (PLC) in a distributed storage system. In PLC, a user wishes to compute a linear combination of$f\$ messages stored in noncolluding databases while revealing no information about the coefficients of the desired linear combination to the databases. In extension of our previous work we employ linear codes to encode the information on the databases. We show that the PLC capacity, which is the ratio of the desired linear function size and the total amount of downloaded information, matches the maximum distance separable (MDS) coded capacity of private information retrieval for a large class of linear codes that includes MDS codes. In particular, the proposed converse is valid for any number of messages and linear combinations, and the capacity expression depends on the rank of the coefficient matrix obtained from all linear combinations.

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• This research is concerned with finding the roots of a function in an interval using Chebyshev Interpolation. Numerical results of Chebyshev Interpolation are presented to show that this is a powerful way to simultaneously calculate all the roots in an interval.

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