red Filtered expansions in general relativity II. (arXiv:2005.03390v1 [math-ph]) By arxiv.org Published On :: This is the second of two papers in which we construct formal power series solutions in external parameters to the vacuum Einstein equations, implementing one bounce for the Belinskii-Khalatnikov-Lifshitz (BKL) proposal for spatially inhomogeneous spacetimes. Here we show that spatially inhomogeneous perturbations of spatially homogeneous elements are unobstructed. A spectral sequence for a filtered complex, and a homological contraction based on gauge-fixing, are used to do this. Full Article
red A reducibility problem for even Unitary groups: The depth zero case. (arXiv:2005.03386v1 [math.RT]) By arxiv.org Published On :: We study a problem concerning parabolic induction in certain p-adic unitary groups. More precisely, for $E/F$ a quadratic extension of p-adic fields the associated unitary group $G=mathrm{U}(n,n)$ contains a parabolic subgroup $P$ with Levi component $L$ isomorphic to $mathrm{GL}_n(E)$. Let $pi$ be an irreducible supercuspidal representation of $L$ of depth zero. We use Hecke algebra methods to determine when the parabolically induced representation $iota_P^G pi$ is reducible. Full Article
red A Chance Constraint Predictive Control and Estimation Framework for Spacecraft Descent with Field Of View Constraints. (arXiv:2005.03245v1 [math.OC]) By arxiv.org Published On :: Recent studies of optimization methods and GNC of spacecraft near small bodies focusing on descent, landing, rendezvous, etc., with key safety constraints such as line-of-sight conic zones and soft landings have shown promising results; this paper considers descent missions to an asteroid surface with a constraint that consists of an onboard camera and asteroid surface markers while using a stochastic convex MPC law. An undermodeled asteroid gravity and spacecraft technology inspired measurement model is established to develop the constraint. Then a computationally light stochastic Linear Quadratic MPC strategy is presented to keep the spacecraft in satisfactory field of view of the surface markers while trajectory tracking, employing chance based constraints and up-to-date estimation uncertainty from navigation. The estimation uncertainty giving rise to the tightened constraints is particularly addressed. Results suggest robust tracking performance across a variety of trajectories. Full Article
red Irreducible representations of Braid Group $B_n$ of dimension $n+1$. (arXiv:2005.03105v1 [math.GR]) By arxiv.org Published On :: We prove that there are no irreducible representations of $B_n$ of dimension $n+1$ for $ngeq 10.$ Full Article
red On the list recoverability of randomly punctured codes. (arXiv:2005.02478v2 [math.CO] UPDATED) By arxiv.org Published On :: We show that a random puncturing of a code with good distance is list recoverable beyond the Johnson bound. In particular, this implies that there are Reed-Solomon codes that are list recoverable beyond the Johnson bound. It was previously known that there are Reed-Solomon codes that do not have this property. As an immediate corollary to our main theorem, we obtain better degree bounds on unbalanced expanders that come from Reed-Solomon codes. Full Article
red Temporal Event Segmentation using Attention-based Perceptual Prediction Model for Continual Learning. (arXiv:2005.02463v2 [cs.CV] UPDATED) By arxiv.org Published On :: Temporal event segmentation of a long video into coherent events requires a high level understanding of activities' temporal features. The event segmentation problem has been tackled by researchers in an offline training scheme, either by providing full, or weak, supervision through manually annotated labels or by self-supervised epoch based training. In this work, we present a continual learning perceptual prediction framework (influenced by cognitive psychology) capable of temporal event segmentation through understanding of the underlying representation of objects within individual frames. Our framework also outputs attention maps which effectively localize and track events-causing objects in each frame. The model is tested on a wildlife monitoring dataset in a continual training manner resulting in $80\%$ recall rate at $20\%$ false positive rate for frame level segmentation. Activity level testing has yielded $80\%$ activity recall rate for one false activity detection every 50 minutes. Full Article
red Prediction of Event Related Potential Speller Performance Using Resting-State EEG. (arXiv:2005.01325v3 [cs.HC] UPDATED) By arxiv.org Published On :: Event-related potential (ERP) speller can be utilized in device control and communication for locked-in or severely injured patients. However, problems such as inter-subject performance instability and ERP-illiteracy are still unresolved. Therefore, it is necessary to predict classification performance before performing an ERP speller in order to use it efficiently. In this study, we investigated the correlations with ERP speller performance using a resting-state before an ERP speller. In specific, we used spectral power and functional connectivity according to four brain regions and five frequency bands. As a result, the delta power in the frontal region and functional connectivity in the delta, alpha, gamma bands are significantly correlated with the ERP speller performance. Also, we predicted the ERP speller performance using EEG features in the resting-state. These findings may contribute to investigating the ERP-illiteracy and considering the appropriate alternatives for each user. Full Article
red On Rearrangement of Items Stored in Stacks. (arXiv:2002.04979v2 [cs.RO] UPDATED) By arxiv.org Published On :: There are $n ge 2$ stacks, each filled with $d$ items, and one empty stack. Every stack has capacity $d > 0$. A robot arm, in one stack operation (step), may pop one item from the top of a non-empty stack and subsequently push it onto a stack not at capacity. In a {em labeled} problem, all $nd$ items are distinguishable and are initially randomly scattered in the $n$ stacks. The items must be rearranged using pop-and-pushs so that in the end, the $k^{ m th}$ stack holds items $(k-1)d +1, ldots, kd$, in that order, from the top to the bottom for all $1 le k le n$. In an {em unlabeled} problem, the $nd$ items are of $n$ types of $d$ each. The goal is to rearrange items so that items of type $k$ are located in the $k^{ m th}$ stack for all $1 le k le n$. In carrying out the rearrangement, a natural question is to find the least number of required pop-and-pushes. Our main contributions are: (1) an algorithm for restoring the order of $n^2$ items stored in an $n imes n$ table using only $2n$ column and row permutations, and its generalization, and (2) an algorithm with a guaranteed upper bound of $O(nd)$ steps for solving both versions of the stack rearrangement problem when $d le lceil cn ceil$ for arbitrary fixed positive number $c$. In terms of the required number of steps, the labeled and unlabeled version have lower bounds $Omega(nd + nd{frac{log d}{log n}})$ and $Omega(nd)$, respectively. Full Article
red A memory of motion for visual predictive control tasks. (arXiv:2001.11759v3 [cs.RO] UPDATED) By arxiv.org Published On :: This paper addresses the problem of efficiently achieving visual predictive control tasks. To this end, a memory of motion, containing a set of trajectories built off-line, is used for leveraging precomputation and dealing with difficult visual tasks. Standard regression techniques, such as k-nearest neighbors and Gaussian process regression, are used to query the memory and provide on-line a warm-start and a way point to the control optimization process. The proposed technique allows the control scheme to achieve high performance and, at the same time, keep the computational time limited. Simulation and experimental results, carried out with a 7-axis manipulator, show the effectiveness of the approach. Full Article
red A predictive path-following controller for multi-steered articulated vehicles. (arXiv:1912.06259v5 [math.OC] UPDATED) By arxiv.org Published On :: Stabilizing multi-steered articulated vehicles in backward motion is a complex task for any human driver. Unless the vehicle is accurately steered, its structurally unstable joint-angle kinematics during reverse maneuvers can cause the vehicle segments to fold and enter a jack-knife state. In this work, a model predictive path-following controller is proposed enabling automatic low-speed steering control of multi-steered articulated vehicles, comprising a car-like tractor and an arbitrary number of trailers with passive or active steering. The proposed path-following controller is tailored to follow nominal paths that contains full state and control-input information, and is designed to satisfy various physical constraints on the vehicle states as well as saturations and rate limitations on the tractor's curvature and the trailer steering angles. The performance of the proposed model predictive path-following controller is evaluated in a set of simulations for a multi-steered 2-trailer with a car-like tractor where the last trailer has steerable wheels. Full Article
red Active Intent Disambiguation for Shared Control Robots. (arXiv:2005.03652v1 [cs.RO]) By arxiv.org Published On :: Assistive shared-control robots have the potential to transform the lives of millions of people afflicted with severe motor impairments. The usefulness of shared-control robots typically relies on the underlying autonomy's ability to infer the user's needs and intentions, and the ability to do so unambiguously is often a limiting factor for providing appropriate assistance confidently and accurately. The contributions of this paper are four-fold. First, we introduce the idea of intent disambiguation via control mode selection, and present a mathematical formalism for the same. Second, we develop a control mode selection algorithm which selects the control mode in which the user-initiated motion helps the autonomy to maximally disambiguate user intent. Third, we present a pilot study with eight subjects to evaluate the efficacy of the disambiguation algorithm. Our results suggest that the disambiguation system (a) helps to significantly reduce task effort, as measured by number of button presses, and (b) is of greater utility for more limited control interfaces and more complex tasks. We also observe that (c) subjects demonstrated a wide range of disambiguation request behaviors, with the common thread of concentrating requests early in the execution. As our last contribution, we introduce a novel field-theoretic approach to intent inference inspired by dynamic field theory that works in tandem with the disambiguation scheme. Full Article
red Universal Coding and Prediction on Martin-L"of Random Points. (arXiv:2005.03627v1 [math.PR]) By arxiv.org Published On :: We perform an effectivization of classical results concerning universal coding and prediction for stationary ergodic processes over an arbitrary finite alphabet. That is, we lift the well-known almost sure statements to statements about Martin-L"of random sequences. Most of this work is quite mechanical but, by the way, we complete a result of Ryabko from 2008 by showing that each universal probability measure in the sense of universal coding induces a universal predictor in the prequential sense. Surprisingly, the effectivization of this implication holds true provided the universal measure does not ascribe too low conditional probabilities to individual symbols. As an example, we show that the Prediction by Partial Matching (PPM) measure satisfies this requirement. In the almost sure setting, the requirement is superfluous. Full Article
red A Reduced Basis Method For Fractional Diffusion Operators II. (arXiv:2005.03574v1 [math.NA]) By arxiv.org Published On :: We present a novel numerical scheme to approximate the solution map $smapsto u(s) := mathcal{L}^{-s}f$ to partial differential equations involving fractional elliptic operators. Reinterpreting $mathcal{L}^{-s}$ as interpolation operator allows us to derive an integral representation of $u(s)$ which includes solutions to parametrized reaction-diffusion problems. We propose a reduced basis strategy on top of a finite element method to approximate its integrand. Unlike prior works, we deduce the choice of snapshots for the reduced basis procedure analytically. Avoiding further discretization, the integral is interpreted in a spectral setting to evaluate the surrogate directly. Its computation boils down to a matrix approximation $L$ of the operator whose inverse is projected to a low-dimensional space, where explicit diagonalization is feasible. The universal character of the underlying $s$-independent reduced space allows the approximation of $(u(s))_{sin(0,1)}$ in its entirety. We prove exponential convergence rates and confirm the analysis with a variety of numerical examples. Further improvements are proposed in the second part of this investigation to avoid inversion of $L$. Instead, we directly project the matrix to the reduced space, where its negative fractional power is evaluated. A numerical comparison with the predecessor highlights its competitive performance. Full Article
red Credulous Users and Fake News: a Real Case Study on the Propagation in Twitter. (arXiv:2005.03550v1 [cs.SI]) By arxiv.org Published On :: Recent studies have confirmed a growing trend, especially among youngsters, of using Online Social Media as favourite information platform at the expense of traditional mass media. Indeed, they can easily reach a wide audience at a high speed; but exactly because of this they are the preferred medium for influencing public opinion via so-called fake news. Moreover, there is a general agreement that the main vehicle of fakes news are malicious software robots (bots) that automatically interact with human users. In previous work we have considered the problem of tagging human users in Online Social Networks as credulous users. Specifically, we have considered credulous those users with relatively high number of bot friends when compared to total number of their social friends. We consider this group of users worth of attention because they might have a higher exposure to malicious activities and they may contribute to the spreading of fake information by sharing dubious content. In this work, starting from a dataset of fake news, we investigate the behaviour and the degree of involvement of credulous users in fake news diffusion. The study aims to: (i) fight fake news by considering the content diffused by credulous users; (ii) highlight the relationship between credulous users and fake news spreading; (iii) target fake news detection by focusing on the analysis of specific accounts more exposed to malicious activities of bots. Our first results demonstrate a strong involvement of credulous users in fake news diffusion. This findings are calling for tools that, by performing data streaming on credulous' users actions, enables us to perform targeted fact-checking. Full Article
red Predictions and algorithmic statistics for infinite sequence. (arXiv:2005.03467v1 [cs.IT]) By arxiv.org Published On :: Consider the following prediction problem. Assume that there is a block box that produces bits according to some unknown computable distribution on the binary tree. We know first $n$ bits $x_1 x_2 ldots x_n$. We want to know the probability of the event that that the next bit is equal to $1$. Solomonoff suggested to use universal semimeasure $m$ for solving this task. He proved that for every computable distribution $P$ and for every $b in {0,1}$ the following holds: $$sum_{n=1}^{infty}sum_{x: l(x)=n} P(x) (P(b | x) - m(b | x))^2 < infty .$$ However, Solomonoff's method has a negative aspect: Hutter and Muchnik proved that there are an universal semimeasure $m$, computable distribution $P$ and a random (in Martin-L{"o}f sense) sequence $x_1 x_2ldots$ such that $lim_{n o infty} P(x_{n+1} | x_1ldots x_n) - m(x_{n+1} | x_1ldots x_n) rightarrow 0$. We suggest a new way for prediction. For every finite string $x$ we predict the new bit according to the best (in some sence) distribution for $x$. We prove the similar result as Solomonoff theorem for our way of prediction. Also we show that our method of prediction has no that negative aspect as Solomonoff's method. Full Article
red A combination of 'pooling' with a prediction model can reduce by 73% the number of COVID-19 (Corona-virus) tests. (arXiv:2005.03453v1 [cs.LG]) By arxiv.org Published On :: We show that combining a prediction model (based on neural networks), with a new method of test pooling (better than the original Dorfman method, and better than double-pooling) called 'Grid', we can reduce the number of Covid-19 tests by 73%. Full Article
red An Experimental Study of Reduced-Voltage Operation in Modern FPGAs for Neural Network Acceleration. (arXiv:2005.03451v1 [cs.LG]) By arxiv.org Published On :: We empirically evaluate an undervolting technique, i.e., underscaling the circuit supply voltage below the nominal level, to improve the power-efficiency of Convolutional Neural Network (CNN) accelerators mapped to Field Programmable Gate Arrays (FPGAs). Undervolting below a safe voltage level can lead to timing faults due to excessive circuit latency increase. We evaluate the reliability-power trade-off for such accelerators. Specifically, we experimentally study the reduced-voltage operation of multiple components of real FPGAs, characterize the corresponding reliability behavior of CNN accelerators, propose techniques to minimize the drawbacks of reduced-voltage operation, and combine undervolting with architectural CNN optimization techniques, i.e., quantization and pruning. We investigate the effect of environmental temperature on the reliability-power trade-off of such accelerators. We perform experiments on three identical samples of modern Xilinx ZCU102 FPGA platforms with five state-of-the-art image classification CNN benchmarks. This approach allows us to study the effects of our undervolting technique for both software and hardware variability. We achieve more than 3X power-efficiency (GOPs/W) gain via undervolting. 2.6X of this gain is the result of eliminating the voltage guardband region, i.e., the safe voltage region below the nominal level that is set by FPGA vendor to ensure correct functionality in worst-case environmental and circuit conditions. 43% of the power-efficiency gain is due to further undervolting below the guardband, which comes at the cost of accuracy loss in the CNN accelerator. We evaluate an effective frequency underscaling technique that prevents this accuracy loss, and find that it reduces the power-efficiency gain from 43% to 25%. Full Article
red Joint Prediction and Time Estimation of COVID-19 Developing Severe Symptoms using Chest CT Scan. (arXiv:2005.03405v1 [eess.IV]) By arxiv.org Published On :: With the rapidly worldwide spread of Coronavirus disease (COVID-19), it is of great importance to conduct early diagnosis of COVID-19 and predict the time that patients might convert to the severe stage, for designing effective treatment plan and reducing the clinicians' workloads. In this study, we propose a joint classification and regression method to determine whether the patient would develop severe symptoms in the later time, and if yes, predict the possible conversion time that the patient would spend to convert to the severe stage. To do this, the proposed method takes into account 1) the weight for each sample to reduce the outliers' influence and explore the problem of imbalance classification, and 2) the weight for each feature via a sparsity regularization term to remove the redundant features of high-dimensional data and learn the shared information across the classification task and the regression task. To our knowledge, this study is the first work to predict the disease progression and the conversion time, which could help clinicians to deal with the potential severe cases in time or even save the patients' lives. Experimental analysis was conducted on a real data set from two hospitals with 422 chest computed tomography (CT) scans, where 52 cases were converted to severe on average 5.64 days and 34 cases were severe at admission. Results show that our method achieves the best classification (e.g., 85.91% of accuracy) and regression (e.g., 0.462 of the correlation coefficient) performance, compared to all comparison methods. Moreover, our proposed method yields 76.97% of accuracy for predicting the severe cases, 0.524 of the correlation coefficient, and 0.55 days difference for the converted time. Full Article
red DramaQA: Character-Centered Video Story Understanding with Hierarchical QA. (arXiv:2005.03356v1 [cs.CL]) By arxiv.org Published On :: Despite recent progress on computer vision and natural language processing, developing video understanding intelligence is still hard to achieve due to the intrinsic difficulty of story in video. Moreover, there is not a theoretical metric for evaluating the degree of video understanding. In this paper, we propose a novel video question answering (Video QA) task, DramaQA, for a comprehensive understanding of the video story. The DramaQA focused on two perspectives: 1) hierarchical QAs as an evaluation metric based on the cognitive developmental stages of human intelligence. 2) character-centered video annotations to model local coherence of the story. Our dataset is built upon the TV drama "Another Miss Oh" and it contains 16,191 QA pairs from 23,928 various length video clips, with each QA pair belonging to one of four difficulty levels. We provide 217,308 annotated images with rich character-centered annotations, including visual bounding boxes, behaviors, and emotions of main characters, and coreference resolved scripts. Additionally, we provide analyses of the dataset as well as Dual Matching Multistream model which effectively learns character-centered representations of video to answer questions about the video. We are planning to release our dataset and model publicly for research purposes and expect that our work will provide a new perspective on video story understanding research. Full Article
red Database Traffic Interception for Graybox Detection of Stored and Context-Sensitive XSS. (arXiv:2005.03322v1 [cs.CR]) By arxiv.org Published On :: XSS is a security vulnerability that permits injecting malicious code into the client side of a web application. In the simplest situations, XSS vulnerabilities arise when a web application includes the user input in the web output without due sanitization. Such simple XSS vulnerabilities can be detected fairly reliably with blackbox scanners, which inject malicious payload into sensitive parts of HTTP requests and look for the reflected values in the web output. Contemporary blackbox scanners are not effective against stored XSS vulnerabilities, where the malicious payload in an HTTP response originates from the database storage of the web application, rather than from the associated HTTP request. Similarly, many blackbox scanners do not systematically handle context-sensitive XSS vulnerabilities, where the user input is included in the web output after a transformation that prevents the scanner from recognizing the original value, but does not sanitize the value sufficiently. Among the combination of two basic data sources (stored vs reflected) and two basic vulnerability patterns (context sensitive vs not so), only one is therefore tested systematically by state-of-the-art blackbox scanners. Our work focuses on systematic coverage of the three remaining combinations. We present a graybox mechanism that extends a general purpose database to cooperate with our XSS scanner, reporting and injecting the test inputs at the boundary between the database and the web application. Furthermore, we design a mechanism for identifying the injected inputs in the web output even after encoding by the web application, and check whether the encoding sanitizes the injected inputs correctly in the respective browser context. We evaluate our approach on eight mature and technologically diverse web applications, discovering previously unknown and exploitable XSS flaws in each of those applications. Full Article
red Structured inversion of the Bernstein-Vandermonde Matrix. (arXiv:2005.03251v1 [math.NA]) By arxiv.org Published On :: Bernstein polynomials, long a staple of approximation theory and computational geometry, have also increasingly become of interest in finite element methods. Many fundamental problems in interpolation and approximation give rise to interesting linear algebra questions. When attempting to find a polynomial approximation of boundary or initial data, one encounters the Bernstein-Vandermonde matrix, which is found to be highly ill-conditioned. Previously, we used the relationship between monomial Bezout matrices and the inverse of Hankel matrices to obtain a decomposition of the inverse of the Bernstein mass matrix in terms of Hankel, Toeplitz, and diagonal matrices. In this paper, we use properties of the Bernstein-Bezout matrix to factor the inverse of the Bernstein-Vandermonde matrix into a difference of products of Hankel, Toeplitz, and diagonal matrices. We also use a nonstandard matrix norm to study the conditioning of the Bernstein-Vandermonde matrix, showing that the conditioning in this case is better than in the standard 2-norm. Additionally, we use properties of multivariate Bernstein polynomials to derive a block $LU$ decomposition of the Bernstein-Vandermonde matrix corresponding to equispaced nodes on the $d$-simplex. Full Article
red Hierarchical Predictive Coding Models in a Deep-Learning Framework. (arXiv:2005.03230v1 [cs.CV]) By arxiv.org Published On :: Bayesian predictive coding is a putative neuromorphic method for acquiring higher-level neural representations to account for sensory input. Although originating in the neuroscience community, there are also efforts in the machine learning community to study these models. This paper reviews some of the more well known models. Our review analyzes module connectivity and patterns of information transfer, seeking to find general principles used across the models. We also survey some recent attempts to cast these models within a deep learning framework. A defining feature of Bayesian predictive coding is that it uses top-down, reconstructive mechanisms to predict incoming sensory inputs or their lower-level representations. Discrepancies between the predicted and the actual inputs, known as prediction errors, then give rise to future learning that refines and improves the predictive accuracy of learned higher-level representations. Predictive coding models intended to describe computations in the neocortex emerged prior to the development of deep learning and used a communication structure between modules that we name the Rao-Ballard protocol. This protocol was derived from a Bayesian generative model with some rather strong statistical assumptions. The RB protocol provides a rubric to assess the fidelity of deep learning models that claim to implement predictive coding. Full Article
red Diagnosis of Coronavirus Disease 2019 (COVID-19) with Structured Latent Multi-View Representation Learning. (arXiv:2005.03227v1 [eess.IV]) By arxiv.org Published On :: Recently, the outbreak of Coronavirus Disease 2019 (COVID-19) has spread rapidly across the world. Due to the large number of affected patients and heavy labor for doctors, computer-aided diagnosis with machine learning algorithm is urgently needed, and could largely reduce the efforts of clinicians and accelerate the diagnosis process. Chest computed tomography (CT) has been recognized as an informative tool for diagnosis of the disease. In this study, we propose to conduct the diagnosis of COVID-19 with a series of features extracted from CT images. To fully explore multiple features describing CT images from different views, a unified latent representation is learned which can completely encode information from different aspects of features and is endowed with promising class structure for separability. Specifically, the completeness is guaranteed with a group of backward neural networks (each for one type of features), while by using class labels the representation is enforced to be compact within COVID-19/community-acquired pneumonia (CAP) and also a large margin is guaranteed between different types of pneumonia. In this way, our model can well avoid overfitting compared to the case of directly projecting highdimensional features into classes. Extensive experimental results show that the proposed method outperforms all comparison methods, and rather stable performances are observed when varying the numbers of training data. Full Article
red Shared Autonomy with Learned Latent Actions. (arXiv:2005.03210v1 [cs.RO]) By arxiv.org Published On :: Assistive robots enable people with disabilities to conduct everyday tasks on their own. However, these tasks can be complex, containing both coarse reaching motions and fine-grained manipulation. For example, when eating, not only does one need to move to the correct food item, but they must also precisely manipulate the food in different ways (e.g., cutting, stabbing, scooping). Shared autonomy methods make robot teleoperation safer and more precise by arbitrating user inputs with robot controls. However, these works have focused mainly on the high-level task of reaching a goal from a discrete set, while largely ignoring manipulation of objects at that goal. Meanwhile, dimensionality reduction techniques for teleoperation map useful high-dimensional robot actions into an intuitive low-dimensional controller, but it is unclear if these methods can achieve the requisite precision for tasks like eating. Our insight is that---by combining intuitive embeddings from learned latent actions with robotic assistance from shared autonomy---we can enable precise assistive manipulation. In this work, we adopt learned latent actions for shared autonomy by proposing a new model structure that changes the meaning of the human's input based on the robot's confidence of the goal. We show convergence bounds on the robot's distance to the most likely goal, and develop a training procedure to learn a controller that is able to move between goals even in the presence of shared autonomy. We evaluate our method in simulations and an eating user study. Full Article
red Nonlinear model reduction: a comparison between POD-Galerkin and POD-DEIM methods. (arXiv:2005.03173v1 [physics.comp-ph]) By arxiv.org Published On :: Several nonlinear model reduction techniques are compared for the three cases of the non-parallel version of the Kuramoto-Sivashinsky equation, the transient regime of flow past a cylinder at $Re=100$ and fully developed flow past a cylinder at the same Reynolds number. The linear terms of the governing equations are reduced by Galerkin projection onto a POD basis of the flow state, while the reduced nonlinear convection terms are obtained either by a Galerkin projection onto the same state basis, by a Galerkin projection onto a POD basis representing the nonlinearities or by applying the Discrete Empirical Interpolation Method (DEIM) to a POD basis of the nonlinearities. The quality of the reduced order models is assessed as to their stability, accuracy and robustness, and appropriate quantitative measures are introduced and compared. In particular, the properties of the reduced linear terms are compared to those of the full-scale terms, and the structure of the nonlinear quadratic terms is analyzed as to the conservation of kinetic energy. It is shown that all three reduction techniques provide excellent and similar results for the cases of the Kuramoto-Sivashinsky equation and the limit-cycle cylinder flow. For the case of the transient regime of flow past a cylinder, only the pure Galerkin techniques are successful, while the DEIM technique produces reduced-order models that diverge in finite time. Full Article
red A Gentle Introduction to Quantum Computing Algorithms with Applications to Universal Prediction. (arXiv:2005.03137v1 [quant-ph]) By arxiv.org Published On :: In this technical report we give an elementary introduction to Quantum Computing for non-physicists. In this introduction we describe in detail some of the foundational Quantum Algorithms including: the Deutsch-Jozsa Algorithm, Shor's Algorithm, Grocer Search, and Quantum Counting Algorithm and briefly the Harrow-Lloyd Algorithm. Additionally we give an introduction to Solomonoff Induction, a theoretically optimal method for prediction. We then attempt to use Quantum computing to find better algorithms for the approximation of Solomonoff Induction. This is done by using techniques from other Quantum computing algorithms to achieve a speedup in computing the speed prior, which is an approximation of Solomonoff's prior, a key part of Solomonoff Induction. The major limiting factors are that the probabilities being computed are often so small that without a sufficient (often large) amount of trials, the error may be larger than the result. If a substantial speedup in the computation of an approximation of Solomonoff Induction can be achieved through quantum computing, then this can be applied to the field of intelligent agents as a key part of an approximation of the agent AIXI. Full Article
red What Soccer Was Like When Retired Soccer Star Briana Scurry First Started Playing By feedproxy.google.com Published On :: Thu, 23 Jan 2014 00:00:00 EST Soccer great Briana Scurry started playing soccer at 12 on an all boys team and in the goal — the "safest" position for a girl ... Full Article video
red Retired Soccer Star Briana Scurry on Sharing "Her Hell" By feedproxy.google.com Published On :: Thu, 23 Jan 2014 00:00:00 EST For a long time after her injury, soccer great Briana Scurry "hid her hell." Now, she knows that that was not the right thing to do and she wants to teach others to become more open and understanding about concussion. Full Article video
red Retired Soccer Star Briana Scurry on What a Concussion Feels Like By feedproxy.google.com Published On :: Thu, 23 Jan 2014 00:00:00 EST After she was hit, retired soccer star Briana Scurry felt off balance, sensitive to light and sound,and felt intense pain in her head and neck. Full Article video
red Retired Soccer Star Briana Scurry: "This Has Been the Most Difficult Thing" By feedproxy.google.com Published On :: Thu, 23 Jan 2014 00:00:00 EST "The penalty kicks, the final goals in the Olympics, playing in front of the president, in front of 90,000 people ... that is what I was born to do ... and my brain is what I used to get myself there." Full Article video
red Retired Soccer Star Briana Scurry: Message to People Struggling After Concussions By feedproxy.google.com Published On :: Thu, 23 Jan 2014 00:00:00 EST If you don't feel right after a concussion, talk to your parents, your coach, your doctor ... get a second, third, fourth opinion ... Do not accept that you will not get better. Full Article video
red How Occipital Nerve Surgery Helped Retired Soccer Star Briana Scurry By feedproxy.google.com Published On :: Thu, 23 Jan 2014 00:00:00 EST Bilateral occipital nerve release surgery was the first, significant step to relieving Scurry's debilitating post-concussive headaches. Full Article video
red Retired Soccer Star Briana Scurry on Girls Soccer and Concussion Protocols By feedproxy.google.com Published On :: Thu, 23 Jan 2014 00:00:00 EST One out of two girls will sustain a concussion playing soccer, but most will recover and return to play with ease. Nevertheless, awareness and education are key to keeping players safe. Full Article video
red Retired Soccer Star Briana Scurry on "Being Me Again" By feedproxy.google.com Published On :: Thu, 23 Jan 2014 00:00:00 EST "The Briana Scurry who could tune out 90,000 people during the World Cup and focus on a single ball and know I could keep it out of the goal ... that is who I want to be again." Full Article video
red Retired Soccer Star Briana Scurry: "My Brain Was Broken" By feedproxy.google.com Published On :: Thu, 23 Jan 2014 00:00:00 EST Retired soccer star Briana Scurry talks about how all her successes started with her mind and her ability to overcome obstacles. After her injury, she felt lost, broken. Full Article video
red Retired Soccer Star Briana Scurry on Her Post-Concussion Depression By feedproxy.google.com Published On :: Thu, 23 Jan 2014 00:00:00 EST Was her depression physiological from the hit to her head or because her professional soccer career was over? Full Article video
red When Retired Soccer Star Briana Scurry Knew Her Career Was Over By feedproxy.google.com Published On :: Thu, 23 Jan 2014 00:00:00 EST After several weeks of not playing because of a concussion and then failing several baseline tests, Briana Scurry became very worried. Full Article video
red Why Retired Soccer Star Briana Scurry Is Speaking Out About Concussion By feedproxy.google.com Published On :: Thu, 23 Jan 2014 00:00:00 EST As someone who had a phenomenal career in professional soccer and that had a career-ending head injury, Briana Scurry knows she can help other female — and male — athletes. Full Article video
red Website Redesign Checklist + 7 Handy Website Redesign Tips By feedproxy.google.com Published On :: Fri, 25 Oct 2019 16:34:12 +0000 Does your website feature design straight out of the ’90s and functionality from the stone age? If so, it’s time for an upgrade — and WebFX can help. When it comes to website redesign checklists, we’re at the top of our game, and we know how to get things done. But where do you start […] The post Website Redesign Checklist + 7 Handy Website Redesign Tips appeared first on WebFX Blog. Full Article Web Design
red Website Redesign Process: Your Website Redesign Strategy in 5 Steps By feedproxy.google.com Published On :: Sat, 07 Mar 2020 17:50:21 +0000 Your website is your virtual business card and it often provides the first impression of your business to future customers — making it one of the most important aspects of your company. But if your website still has cobwebs from the 2000s, it’s time to put together a website redesign process. A website redesign process […] The post Website Redesign Process: Your Website Redesign Strategy in 5 Steps appeared first on WebFX Blog. Full Article Web Design
red Experimental Biomass Harvest a Step Toward Sustainable, Biofuels-Powered Future By feedproxy.google.com Published On :: Thu, 17 Mar 2016 18:58:41 +0000 By Jeff Mulhollem Penn State News The first harvest of 34 acres of fast-growing shrub willow from a Penn State demonstration field this winter is a milestone in developing a sustainable biomass supply for renewable energy and bio-based economic development, … Continue reading → Full Article Biomass agriculture Bio Fuel bio mass
red Trump administration models predict near doubling of daily death toll by June By www.inlander.com Published On :: Mon, 04 May 2020 14:21:00 -0700 By The New York Times The New York Times Company As President Donald Trump presses for states to reopen their economies, his administration is privately projecting a steady rise in the number of cases and deaths from the coronavirus over the next several weeks, reaching about 3,000 daily deaths June 1, according to an internal document obtained by The New York Times, nearly double from the current level of about 1,750.… Full Article Nation & World
red The Spokane County Sheriff's Office has discretely acquired technology that enables them to bypass phone passwords By www.inlander.com Published On :: Thu, 07 May 2020 01:30:00 -0700 Cops are hackers now, too.… Full Article News/Local News
red GOOD NEWS: These local insects never murdered anybody that we know of By www.inlander.com Published On :: Fri, 08 May 2020 15:56:15 -0700 Last week, the New York Times dropped a terrifying story: Asian Giant Hornets, or "murder hornets" as more J. Jonah Jameson-esque researchers like to call them, have been identified in Western Washington. These insects can grow up to 2 inches long, can rip the heads off an entire hive of honeybees in a matter of hours, and have dagger-like stingers that pierce beekeeper suits to deliver a sting that sears like molten acid.… Full Article News/Local News
red Graphene prepared by using edge functionalization of graphite By www.freepatentsonline.com Published On :: Tue, 28 Apr 2015 08:00:00 EDT Disclosed is a method for producing graphene functionalized at its edge positions of graphite. Organic material having one or more functional groups is reacted with graphite in reaction medium comprising methanesulfonic acid and phosphorus pentoxide, or in reaction medium comprising trifluoromethanesulfonic acid, to produce graphene having organic material fuctionalized at edges. And then, high purity and large scaled graphene and film can be obtained by dispersing, centrifugal separating the functionalized graphene in a solvent and reducing, in particular heat treating the graphene. According to the present invention graphene can be produced inexpensively in a large amount with a minimum loss of graphite. (FIG. 1) Full Article
red Process for reductive amination of aliphatic cyanoaldehydes to aliphatic diamines By www.freepatentsonline.com Published On :: Tue, 05 May 2015 08:00:00 EDT A process for reductive amination of aliphatic cyanoaldehydes to aliphatic diamines comprising (1) providing a mixture of 1,3-cyanocyclohexane carboxaldehyde and/or 1,4-cyanocyclohexane carboxaldehyde; (2) contacting said mixture with a metal carbonate based solid bed or a weak base anion exchange resin bed at a temperature from 15 to 40 ° C. for a period of at least 1 minute; (3) thereby treating said mixture, wherein said treated mixture has a pH in the range of 6 to 9; (4) feeding said treated mixture, hydrogen, and ammonia into a continuous reductive amination reactor system; (6) contacting said treated mixture, hydrogen, and ammonia with each other in the presence of one or more heterogeneous metal based catalyst systems at a temperature from 80 ° C. to 160 ° C. and a pressure from 700 to 3500 psig; (7) thereby producing one or more cycloaliphatic diamines is provided. Full Article
red Anti-microbial and anti-static surface treatment agent with quaternary ammonium salt as active ingredient and method for preventing static electricity in polymer fibers using same By www.freepatentsonline.com Published On :: Tue, 12 May 2015 08:00:00 EDT Provided are an anti-static and anti-microbial surface treatment agent including a quaternary ammonium salt compound as an active ingredient and a method of preventing a polymer fiber from developing static electricity by using the surface treatment agent. The quaternary ammonium salt compound has excellent anti-static and anti-microbial effects for the prevention or improvement of static electricity in a polymer fiber. Accordingly, the quaternary ammonium salt compound is suitable for use as a fabric softener, or an anti-static agent, and also, provides anti-microbial effects to a polymer fiber. Full Article
red Aminoethylation process having improved yield of aryloxyalkylene amine compounds and reduced urea by-products By www.freepatentsonline.com Published On :: Tue, 19 May 2015 08:00:00 EDT Disclosed is a process for preparing an aryloxyalkylene amine compound via an aminoethylation reaction comprising: a) reacting an aromatic hydroxyl compound in the presence of a basic catalyst with a 2-oxazolidinone compound of the formula II to form an intermediate reaction product; wherein R3 is selected from the group consisting of hydrogen or lower alkyl having 1 to 6 carbon atoms, R4 is selected from the group consisting of hydrogen, straight or branched chain alkyl having from one to six carbon atoms, phenyl, alkaryl, or arylalkyl; and b) reacting the intermediate product of step a) with a polyalkylene polyamine. Full Article
red Parsing and rendering structured images By www.freepatentsonline.com Published On :: Tue, 12 May 2015 08:00:00 EDT Systems and methods for generating a tuple of structured data files are described herein. In one example, a method includes detecting an expression that describes a structure of a structured image using a constructor. The method can also include using an inference-rule based search strategy to identify a hierarchical arrangement of bounding boxes in the structured image that match the expression. Furthermore, the method can include generating a first tuple of structured data files based on the identified hierarchical arrangement of bounding boxes in the structured image. Full Article
red Modeling of time-variant threshability due to interactions between a crop in a field and atmospheric and soil conditions for prediction of daily opportunity windows for harvest operations using field-level diagnosis and prediction of weather conditions an By www.freepatentsonline.com Published On :: Tue, 19 May 2015 08:00:00 EDT A modeling framework for evaluating the impact of weather conditions on farming and harvest operations applies real-time, field-level weather data and forecasts of meteorological and climatological conditions together with user-provided and/or observed feedback of a present state of a harvest-related condition to agronomic models and to generate a plurality of harvest advisory outputs for precision agriculture. A harvest advisory model simulates and predicts the impacts of this weather information and user-provided and/or observed feedback in one or more physical, empirical, or artificial intelligence models of precision agriculture to analyze crops, plants, soils, and resulting agricultural commodities, and provides harvest advisory outputs to a diagnostic support tool for users to enhance farming and harvest decision-making, whether by providing pre-, post-, or in situ-harvest operations and crop analyzes. Full Article