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## 信息流

•   03-23 Ars Technica 18

Spying concerns have now totally shut down Huawei's retail presence.

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•   03-23 Hacker News 13

Genetic analysis of tiny mummified skeleton from the Atacama Desert

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•   03-23 Hacker News 12

Charles Lazarus, the founder of retail chain Toys ‘R’ Us, has died

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•   03-23 Ars Technica 12

"Game Workers Unite" push leads to some contentious discussions.

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• Circular Shock Acoustic Waves in Ionosphere Triggered by Launch of Formosat‐5

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•   03-23 Hacker News 11

Ask HN: How do you find freelance work?

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• Playground Global leads a sizeable round with the goal of turning walking robots into useful tools

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•   03-23 Ars Technica 13

And narrow down the window of breeding between our species.

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•   03-23 THE NEW YORKER 12

Best Friends Dept.

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•   03-23 Ars Technica 11

Plus up to 30% off Amazon Alexa devices, an Essential Phone discount, and more.

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•   03-23 Hacker News 13

D3.js 5.0 is out

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• Ever since the Tempe police released a video of Uber's self-driving car hitting and killing a pedestrian, experts have been racing to analyze the footage and determine what exactly went wrong. (If you haven't watched the video, you can do so here. Warning: it's disturbing, though the actual impact is removed.) In a blog post, software architect and entrepreneur Brad Templeton highlights some of the big issues with the video: 1. On this empty road, the LIDAR is very capable of detecting her. If it was operating, there is no way that it did not detect her 3 to 4 seconds before the impact, if not earlier. She would have come into range just over 5 seconds before impact. 2.On the dash-cam style video, we only see her 1.5 seconds before impact. However, the human eye and quality cameras have a much better dynamic range than this video, and should have also been able to see her even before 5 seconds. From just the dash-cam video, no human could brake in time with just 1.5 seconds warning.

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•   03-23 MIT Technology 12

Amazon is a notoriously secretive company, but its recent conference provides a glance at its far-out plans.

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•   03-23 THE NEW YORKER 12

Annals of Thought

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•   03-23 Slashdot 14

BMW will not mass produce electric cars until 2020 because its current technology is not profitable enough to scale up for volume production, the chief executive said on Thursday. From a report: Munich-based BMW unveiled its first battery electric car in 2013, and has been working on different generations of battery, software and electric motor technology since then. The i8 Roadster model, due to hit showrooms in May, is equipped with what BMW calls its fourth-generation electric drive technology. Advances in battery raw materials and chemistry has increased its range by 40 percent over the previous version, BMW said. BMW is working to make electric car technology more modular and scalable to make mass production commercially viable. "We wanted to wait for the fifth generation to be much more cost competitive," Chief Executive Harald Krueger told analysts in Munich. "We do not want to scale up with the fourth generation."

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• New mesh Wi-Fi networks improve coverage, but at the cost of interoperability

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• An anonymous reader shares a report: The pedestrian killed Sunday by a self-driving Uber SUV had crossed at least one open lane of road before being hit, according to a video of the crash that raises new questions about autonomous-vehicle technology. Forensic crash analysts who reviewed the video said a human driver could have responded more quickly to the situation, potentially saving the life of the victim, 49-year-old Elaine Herzberg. Other experts said Uber's self-driving sensors should have detected the pedestrian as she walked a bicycle across the open road at 10 p.m., despite the dark conditions. Herzberg's death is the first major test of a nascent autonomous vehicle industry that has presented the technology as safer than humans who often get distracted while driving. For human driving in the U.S., there's roughly one death every 86 million miles, while autonomous vehicles have driven no more than 15 to 20 million miles in the country so far, according to Morgan Stanley analys

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•   03-23 MIT Technology 12

The SEC is cracking down on ICOs. But blockchain-based fund-raising won’t die—it will just evolve.

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•   03-23 Ars Technica 12

This truck is all about function over form.

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• Guccifer 2.0 Slipped Up and Revealed He Was a Russian Intelligence Officer

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•   03-23 Hacker News 11

BMW says electric car mass production not viable until 2020

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• An anonymous reader quotes a report from Ars Technica: The city of Atlanta government has apparently become the victim of a ransomware attack. The city's official Twitter account announced that the city government "is currently experiencing outages on various customer facing applications, including some that customers may use to pay bills or access court-related information." According to a report from Atlanta NBC affiliate WXIA, a city employee sent the station a screen shot of a ransomware message demanding a payment of $6,800 to unlock each computer or$51,000 to provide all the keys for affected systems. Employees received emails from the city's information technology department instructing them to unplug their computers if they noticed anything suspicious. An internal email shared with WXIA said that the internal systems affected include the city's payroll application. "At this time, our Atlanta Information Management team is working diligently with support from Microsoft to resol

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•   03-23 Ars Technica 13

“Facebook lies within the penumbra of blame,” Maryland woman claims.

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•   03-23 Ars Technica 11

FBI called in as some city services are interrupted, employees told to turn off PCs.

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•   03-23 Slashdot 16

Before Facebook suspended Aleksandr Kogan from its platform for the data harvesting "scam" at the centre of the unfolding Cambridge Analytica scandal, the social media company enjoyed a close enough relationship with the researcher that it provided him with an anonymised, aggregate dataset of 57bn Facebook friendships. From a report: Facebook provided the dataset of "every friendship formed in 2011 in every country in the world at the national aggregate level" to Kogan's University of Cambridge laboratory for a study on international friendships published in Personality and Individual Differences in 2015. Two Facebook employees were named as co-authors of the study, alongside researchers from Cambridge, Harvard and the University of California, Berkeley. Kogan was publishing under the name Aleksandr Spectre at the time. A University of Cambridge press release on the study's publication noted that the paper was "the first output of ongoing research collaborations between Spectre's lab i

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• The geometric Fierz identities are here employed to generate new emergent fermionic fields on the parallelizable (curvatureless, torsionfull) 7-sphere ($S^7$). Employing recently found new classes of spinor fields on the $S^7$ spin bundle, new classes of fermionic fields are obtained from their bilinear covariants by a generalized reconstruction theorem, on the parallelizable $S^7$. Using a generalized non-associative product on the octonionic bundle on the parallelizable $S^7$, these new classes of algebraic spinor fields, lifted onto the parallelizable $S^7$, are shown to correctly transform under the Moufang loop generators on $S^7$.

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• We prove a q-analogue of a Ramanujan-type series of level 1

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• In earlier work in collaboration with Pavel Galashin and Thomas McConville we introduced a version of chip-firing for root systems. Our investigation of root system chip-firing led us to define certain polynomials analogous to Ehrhart polynomials of lattice polytopes, which we termed the symmetric and truncated Ehrhart-like polynomials. We conjectured that these polynomials have nonnegative integer coefficients. Here we affirm "half" of this positivity conjecture by providing a positive, combinatorial formula for the coefficients of the symmetric Ehrhart-like polynomials. This formula depends on a subtle integrality property of slices of permutohedra which may be of independent interest. We also discuss how our formula very naturally suggests a conjecture for the coefficients of the truncated Ehrhart-like polynomials that turns out to be false in general, but which may hold in some cases.

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• We observe that automorphism groups of right-angled Artin groups contain nilpotent non-abelian subgroups, namely $H_3(\mathbb{Z})$ the three-dimensional integer Heisenberg group, provided they admit a certain type of element, called an adjacent transvection. This represents a (minor) extension of a result of Charney-Vogtmann.

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• We study a new construction of bodies from a given convex body in $\mathbb{R}^{n}$ which are isomorphic to (weighted) floating bodies. We establish several properties of this new construction, including its relation to $p$-affine surface areas.

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• In this work, we propose an Action Principle for Action-dependent Lagrangian functions by generalizing the Herglotz variational problem to the case with several independent variables. We obtain a necessary condition for the extremum equivalent to the Euler-Lagrange equation and, through some examples, we show that this generalized Action Principle enables us to construct simple and physically meaningful Action-dependent Lagrangian functions for a wide range of non-conservative classical and quantum systems. Furthermore, when the dependence on the Action is removed, the traditional Action Principle for conservative systems is recovered.

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• We consider a structure $\mathcal {M} = \langle \mathbb N, \{Tr,<\} \rangle$, where the relation $Tr(a,x,y)$ with a parameter $a$ defines a family of trees on $\mathbb N$ and $<$ is the usual order on $\mathbb N$. We show that if the elementary theory of $\mathcal M$ is decidable then (1) the relation $Q( a) \rightleftharpoons$ "there is an infinite branch in the tree $Tr( a,x,y)$" is definable in $\mathcal M$, and (2) if there is an infinite branch in the tree $Tr( a,x,y)$, then there is a definable in $\mathcal M$ infinite branch.

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• One of the phenomena that influences significantly the performance of low-density parity-check codes is known as trapping sets. An $(a,b)$ elementary trapping set, or simply an ETS where $a$ is the size and $b$ is the number of degree-one check nodes and $\frac{b}{a}<1$, causes high decoding failure rate and exert a strong influence on the error floor. In this paper, we provide sufficient conditions for exponent matrices to have fully connected $(3,n)$-regular QC-LDPC codes with girths 6 and 8 whose Tanner graphs are free of small ETSs. Applying sufficient conditions on the exponent matrix to remove some 8-cycles results in removing all 4-cycles, 6-cycles as well as some small elementary trapping sets. For each girth we obtain a lower bound on the lifting degree and present exponent matrices with column weight three whose corresponding Tanner graph is free of certain ETSs.

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• dryriver writes: We live in a time where mainstream media, websites, blogs, social media accounts, your barely computer literate next door neighbor and so forth frequently rave about the "innovation" that is happening everywhere. But as someone who experienced developments in technology back in the 1980s and 1990s, in computing in particular, I cannot shake the feeling that, somehow, the "deep nerds" who were innovating back then did it better and with more heartfelt passion than I can feel today. Of course, tech from 30 years ago seems a bit primitive compared to today -- computer gear is faster and sleeker nowadays. But it seems that the core techniques and core concepts used in much of what is called "innovation" today were invented for the first time one-after-the-other back then, and going back as far as the 1950s maybe. I get the impression that much of what makes billions in profits today and wows everyone is mere improvements on what was actually invented and trail blazed for t

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• As multi-agent networks grow in size and scale, they become increasingly difficult to synchronize, though agents must work together even when generating and sharing different information at different times. Targeting such cases, this paper presents an asynchronous optimization framework in which the time between successive communications and computations is unknown and unspecified for each agent. Agents' updates are carried out in blocks, with each agent updating only a small subset of all decision variables. Each agent uses an independently chosen Tikhonov regularization, and convergence is measured with respect to a weighted block-maximum norm in which agents' blocks can be measured in different p-norms and weighted differently to normalize problems. Asymptotic convergence is shown and convergence rates are derived explicitly in terms of a problem's parameters, with only mild restrictions on what they can be. Simulation results are included to verify the theoretical developments made

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• We consider random polynomials of the form $H_n(z)=\sum_{j=0}^n\xi_jq_j(z)$ where the $\{\xi_j\}$ are i.i.d non-degenerate complex random variables, and the $\{q_j(z)\}$ are orthonormal polynomials with respect to a compactly supported measure $\tau$ satisfying the Bernstein-Markov property on a regular compact set $K \subset \mathbb{C}$. We show that if $\mathbb{P}(|\xi_0|>e^{|z|})=o(|z|^{-1})$, then the normalized counting measure of the zeros of $H_n$ converges weakly in probability to the equilibrium measure of $K.$ This is the best possible result, in the sense that the roots of $G_n(z)=\sum_{j=0}^n\xi_jz^j$ fail to converge in probability to the appropriate equilibrium measure when the above condition on the $\xi_j$ is not satisfied. In addition, we give a multivariable version of this result. We also consider random polynomials of the form $\sum_{k=0}^n\xi_kf_{n,k}z^k$, where the coefficients $f_{n,k}$ are complex constants satisfying certain conditions, and the random variab

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• Assume that we embed the path $P_n$ as a subgraph of a $2$-dimensional grid, namely, $P_k \times P_l$. Given such an embedding, we consider the ordered set of subpaths $L_1, L_2, \ldots , L_m$ which are maximal straight segments in the embedding, and such that the end of $L_i$ is the beginning of $L_{i+1}$. Suppose that $L_i\cong P_2$, for some $i$ and that some vertex $u$ of $L_{i-1}$ is at distance $1$ in the grid to a vertex $v$ of $L_{i+1}$. An elementary transformation of the path consists in replacing the edge of $L_i$ by a new edge $uv$. A tree $T$ of order $n$ is said to be a path-like tree, when it can be obtained from some embedding of $P_n$ in the $2$-dimensional grid, by a sequence of elementary transformations. Thus, the maximum degree of a path-like tree is at most $4$. Intuitively speaking, a tree admits a linear configuration if it can be described by a sequence of paths in such a way that only vertices from two consecutive paths, which are at the same distance of the e

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• We demonstrate a method of associating the principal symbol at a $K$-point with a linear differential operator acting between modules over a commutative algebra, and we use it to define the ellipticity of a linear differential operator in a purely algebraic way. We prove that the ellipticity is preserved by a surjective homomorphism of algebras. As an example, we show that for every real affine variety there is an elliptic linear differential operator acting on the algebra of regular functions on this variety.

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• Despite its numerical challenges, finite element method is used to compute viscous fluid flow. A consensus on the cause of numerical problems has been reached; however, general algorithms---allowing a robust and accurate simulation for any process---are still missing. Either a very high computational cost is necessary for a direct numerical solution (DNS) or some limiting procedure is used by adding artificial dissipation to the system. These stabilization methods are often applied relative to the element size such that a local monotonous convergence cannot be observed. We need a computational strategy for solving viscous fluid flow using only the balance equations. In this work, we present a general procedure solving fluid mechanics problems without use of any stabilization or splitting schemes. Hence its generalization to multiphysics applications is straight-forward. We discuss several numerical problems and present the methodology rigorously. Implementation is achieved by using ope

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• We show that there are no smooth warped AdS$_3$ solutions in 10- and 11-dimensional supergravities which preserve strictly more than 16 supersymmetries and have internal space a compact without boundary manifold.

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• We introduce the oriented Brauer-Clifford and degenerate affine oriented Brauer-Clifford supercategories. These are diagrammatically defined monoidal supercategories which provide combinatorial models for certain natural monoidal supercategories of supermodules and endosuperfunctors, respectively, for the Lie superalgebras of type Q. Our main results are basis theorems for these diagram supercategories. We also discuss connections and applications to the representation theory of the Lie superalgebra of type Q.

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•   03-22 Hacker News 15

Direct X Raytracing: Further Unification

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•   03-22 Hacker News 15

Dejavu – Web UI for Elasticsearch

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•   03-22 Ars Technica 17

AT&T can't force California customers into arbitration, judge says.

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• An anonymous reader quotes a report from Ars Technica: A federal judge has revived a lawsuit that angry customers filed against AT&T over the company's throttling of unlimited mobile data plans. The decision comes two years after the same judge decided that customers could only have their complaints heard individually in arbitration instead of in a class-action lawsuit. The 2016 ruling in AT&T's favor was affirmed by a federal appeals court. But the customers subsequently filed a motion to reconsider the arbitration decision, saying that an April 2017 decision by the California Supreme Court "constitutes a change in law occurring after the Courts arbitration order," Judge Edward Chen of U.S. District Court for the Northern District of California said in the new ruling issued last week. The state Supreme Court "held that an arbitration agreement that waives the right to seek the statutory remedy of public injunctive relief in any forum is contrary to California public policy and

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•   03-22 Ars Technica 15

FCC chair still can’t offer proof that repeal will boost broadband access.

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•   03-22 Ars Technica 15

Critics say law will limit free speech online and won't help trafficking victims.

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•   03-22 Ars Technica 15

We’re looking for a rock star. Know any?

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• An anonymous reader writes: Hi fellow readers. I don't recall reading many comic books as a kid (mostly because I could not afford them), but of late, I have been considering giving that a shot. I wanted to ask if you had any tips to share. Do I start with paperback editions, or do I jump directly into digital? Also, could you recommend a few good sci-fic comic book series? Thanks in advance!

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• Circle Medical (S15) Hiring Nurse Practitioners in SF to Reinvent Primary Care

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•   03-22 THE NEW YORKER 17

Sue Halpern on Cambridge Analytica’s exploitation of Facebook data to push a pro-Trump agenda, and on the actions of Robert Mercer, Alexander Nix, and Christopher Wylie while working for the company.

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•   03-22 THE NEW YORKER 17

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• California should emulate Tokyo, where housing stayed ahead of population growth

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•   03-22 THE NEW YORKER 15

Ali Fitzgerald illustrates a comic about Donald Trump’s relationship to the Peggy Lee song “Is That All There Is?.”

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• Big Other: Surveillance Capitalism and Prospects of an Information Civilization

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•   03-22 Hacker News 14

Facebook Is Not the Internet's Only Privacy Villain

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•   03-22 Hacker News 10

A Visiting Star Jostled Our Solar System 70,000 Years Ago

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• Secure message dissemination is an important issue in vehicular networks, especially considering the vulnerability of vehicle to vehicle message dissemination to malicious attacks. Traditional security mechanisms, largely based on message encryption and key management, can only guarantee secure message exchanges between known source and destination pairs. In vehicular networks however, every vehicle may learn its surrounding environment and contributes as a source, while in the meantime act as a destination or a relay of information from other vehicles, message exchanges often occur between "stranger" vehicles. For secure message dissemination in vehicular networks against insider attackers, who may tamper the content of the disseminated messages, ensuring the consistency and integrity of the transmitted messages becomes a major concern that traditional message encryption and key management based approaches fall short to provide. In this paper, by incorporating the underlying network t

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• In this paper, we study the effects of the variations of the propagation delay over large-scale antenna-arrays used in massive multiple-input multiple-output (MIMO) wideband communication systems on the statistical properties of the channel. Due to its simplicity and popularity, the Elliptical geometry-based stochastic channel model (GBSM) is employed to demonstrate new non-stationary properties of the channel in the frequency and spatial domains caused by the drift of delays. In addition, we show that the time of travel of multi-path components (MPCs) over large-scale arrays may result in overlooked frequency and spatial decorrelation effects. These are theoretically demonstrated by deriving the space-time-frequency correlation functions (STFCFs) of both narrowband and wideband Elliptical models. Closed-form expressions of the array-variant frequency correlation function (FCF), power delay profile (PDP), mean delay, and delay spread of single- and multi-confocal Elliptical models are

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• This is an expository plus research paper which mainly exposes preliminary connection and contrast between classical complex dynamics and semigroup dynamics of holomorphic functions. Classically, we expose some existing results of rational and transcendental dynamics and we see how far these results generalized to holomorphic semigroup dynamics as well as we also see what new phenomena occur.

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• The purpose of this note is to give a number of open problems on matching theory and their relation to the well-known results in this area. We also give a linear analogue of the acyclic matchings.

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• Hybrid dynamical systems have proven to be a powerful modeling abstraction, yet fundamental questions regarding their dynamical properties remain. In this paper, we develop a novel solution concept for a class of hybrid systems, which is a generalization of Filippov's solution concept. In the mathematical theory, these \emph{hybrid Filippov solutions} eliminate the notion of Zeno executions. Building on previous techniques for relaxing hybrid systems, we then introduce a family of smooth control systems that are used to approximate this solution concept. The trajectories of these relaxations vary differentiably with respect to initial conditions and inputs, may be numerically approximated using existing techniques, and are shown to converge to the hybrid Filippov solution in the limit. Finally, we outline how the results of this paper provide a foundation for future work to control hybrid systems using well-established techniques from Control Theory.

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• Deregulated energy markets, demand forecasting, and the continuously increasing share of renewable energy sources call---among others---for a structured consideration of uncertainties in optimal power flow problems. The main challenge is to guarantee power balance while maintaining economic and secure operation. In the presence of Gaussian uncertainties affine feedback policies are known to be viable options for this task. The present paper advocates a general framework for chance-constrained OPF problems in terms of continuous random variables. It is shown that, irrespective of the type of distribution, the random-variable minimizers lead to affine feedback policies. Introducing a three-step methodology that exploits polynomial chaos expansion, the present paper provides a constructive approach to chance-constrained optimal power flow problems that does not assume a specific distribution, e.g. Gaussian, for the uncertainties. We illustrate our findings by means of a tutorial example.

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• Considering a compact Riemann surface of genus greater than two, a Higgs~bundle is a pair composed of a holomorphic bundle over the Riemann surface, joint with an auxiliar vector field, so-called Higgs field. This theory started around thirty years ago, with Hitchin's work, when he reduced the self-duality equations from dimension four to dimension two, and so, studied those equations over Riemann surfaces. Hitchin baptized those fields as "Higgs fields" beacuse in the context of physics and gauge theory, they describe similar particles to those described by the Higgs bosson. Later, Simpson used the name "Higgs bundle" for a holomorphic bundle together with a Higgs field. Today, Higgs bundles are the subject of research in several areas such as non-abelian Hodge theory, Langlands, mirror symmetry, integrable systems, quantum field theory (QFT), among others. The main purposes here are to introduce these objects, and to present a brief construction of the moduli space of Higgs bundles.

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• The Suslin hypothesis states that there are no nonseparable complete dense linear orderings without endpoints which have the countable chain condition. $\mathsf{ZF + AD^+ + V = L(\mathscr{P}(\mathbb{R}))}$ proves the Suslin hypothesis. In particular, if $L(\mathbb{R}) \models \mathsf{AD}$, then $L(\mathbb{R})$ satisfies the Suslin hypothesis, which answers a question of Foreman.

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•   03-22 MIT Technology 15

DNA search finds people resistant to liver disease. Can we mimic the effect with a drug?

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•   03-22 IEEE 14

A helmet records a wearer's brain activity using magnetoencephalography (MEG) while they move around

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• In Menlo Park, Calif., Facebook is building a real community and testing the proposition: Do people love tech companies so much they will live inside them? From a report: Willow Village will be wedged between the Menlo Park neighborhood of Belle Haven and the city of East Palo Alto, both heavily Hispanic communities that are among Silicon Valley's poorest. Facebook is planning 1,500 apartments, and has agreed with Menlo Park to offer 225 of them at below-market rates. The most likely tenants of the full-price units are Facebook employees, who already receive a five-figure bonus if they live near the office. The community will have eight acres of parks, plazas and bike-pedestrian paths open to the public. Facebook wants to revitalize the railway running alongside the property and will finish next year a pedestrian bridge over the expressway. The bridge will provide access to the trail that rings San Francisco Bay, a boon for birders and bikers. Mr. Tenanes, Facebook's vice president for

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•   03-22 Ars Technica 17

If you thought cheating was widespread across the industry, you're probably right.

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• In our previous study of duality for complete discrete valuation fields with perfect residue field, we treated coefficients in finite flat group schemes. In this paper, we treat abelian varieties. This in particular implies Grothendieck's conjecture on the perfectness of his pairing between the Neron component groups of an abelian variety and its dual. The point is that our formulation is well-suited with Galois descent. From the known case of semistable abelian varieties, we deduce the perfectness in full generality. We also treat coefficients in tori and, more generally, 1-motives.

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•   03-22 MIT Technology 12

Amazon, Google, and Microsoft all want to dominate the business of providing artificial-intelligence services through cloud computing. The winner may have the OS of the future.

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• The main purpose of this paper is to find the fixed point in such cases where existing literature remain silent. In this paper we introduce partial completeness, a new type of contraction and many other definitions. Using this approach the existence of fixed point can be proved in incomplete metric spaces with non-contraction map on it. We have reported an example in support our result.

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• Ant Colony System (ACS) is a distributed (agent- based) algorithm which has been widely studied on the Symmetric Travelling Salesman Problem (TSP). The optimum parameters for this algorithm have to be found by trial and error. We use a Particle Swarm Optimization algorithm (PSO) to optimize the ACS parameters working in a designed subset of TSP instances. First goal is to perform the hybrid PSO-ACS algorithm on a single instance to find the optimum parameters and optimum solutions for the instance. Second goal is to analyze those sets of optimum parameters, in relation to instance characteristics. Computational results have shown good quality solutions for single instances though with high computational times, and that there may be sets of parameters that work optimally for a majority of instances.

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• We extend analytic large network results on default contagion in random graphs to capture a pronounced Block Model structure. This includes as a special case the Core-Periphery network structure, which plays a prominent role in recent research on systemic risk. Further, in the existing literature on systemic risk using random graph methods the problematic assumption that the distribution of liabilities solely depends on the creditor type seems to persist. Under this assumption a straightforward application of the law of large numbers allows to turn edge related random elements into deterministic vertex properties. Here we study a general setting in which the liabilities may depend on both the creditor and the debtor where this argument breaks down and a direct asymptotic analysis of the edge weighted random graph becomes necessary. Among several other applications our results allow us to obtain resilience conditions for the entire network (for example the global financial network) base

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•   03-22 Ars Technica 9

In a heartfelt speech, Tim Schafer recalls Will Wright's crucial generosity.

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• The Zap Q-learning algorithm introduced in this paper is an improvement of Watkins' original algorithm and recent competitors in several respects. It is a matrix-gain algorithm designed so that its asymptotic variance is optimal. Moreover, an ODE analysis suggests that the transient behavior is a close match to a deterministic Newton-Raphson implementation. This is made possible by a two time-scale update equation for the matrix gain sequence. The analysis suggests that the approach will lead to stable and efficient computation even for non-ideal parameterized settings. Numerical experiments confirm the quick convergence, even in such non-ideal cases. A secondary goal of this paper is tutorial. The first half of the paper contains a survey on reinforcement learning algorithms, with a focus on minimum variance algorithms.

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• Piecewise deterministic Markov processes (PDMPs) have recently been used for efficient Bayesian analysis of big data, estimation of Boltzmann distributions in molecular dynamics (MD), and hybrid modeling of chemical reaction networks. Such PDMPscan be metastable, considerablyslowing the convergence of sampling. We propose overcoming this obstacle with the parallel replica dynamics (ParRep), which were originally designed to accelerate stochastic MD and more recently have been used to speed up stationary averaging in chemical reaction networks. We show how to use ParRep to accelerate dynamics and stationary computations for PDMPs in the presence of metastability. We present algorithms for synchronous and asynchronous computing environments, and rigorously justify consistency in both settings using a trajectory fragment framework. Since continuous time Markov chains, including reaction network models, are a special case of PDMPs, our results also apply in that setting. Our framework show

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• This is the first in a series of three notes on an investigation into core regular double Stone algebras, CRDSA, and are meant to be read in order. They were born out of a model of network security where individual nodes are considered to be in one of 3 states. Applications of these results are being explored, results of at least one of which will be published at a later date. The two notes following this will establish a duality between the category of CRDSA and specifically crafted bi-topological spaces. Let J be any non-empty set of network nodes, not necessarily finite. We denote the node set bounded distributive lattice through the pairwise disjoint subsets of J with the well known binary operations of ternary set partitions and note J = 1 is our minimal case. We then show the resultant bounded distributive lattice is isomorphic to direct products of the 3 element chain, C_3. We then derive that every CRDSA is a subdirect product of C_3. We use these results along with a few known

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• We study the wave equation in an interval with two linearly moving endpoints. We give the exact solution by a series formula, then we show that the energy of the solution decay at the rate $1/t$. We also establish observability results, at one or two endpoints, in a sharp time. Moreover, using the Hilbert uniqueness method, we derive exact boundary controllability results.

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•   03-22 Hacker News 10

Evolution Is the New Deep Learning

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