I/O虚拟化将重新定义PCI Express的功能

过去几年,PCI Express(以下简称PCIe)总线逐渐成为一种适用于网络应用、具有高效率和成本效益的平台。PCIe的发展是为了克服过去并行计算机总线架构在性能、可扩展性以及配置等方面的限制,这种通用的串行I/O互连技术已被企业型、桌上型、移动、通信及嵌入式等各种应用广泛采用。尽管普及度已相当广泛,业界却普遍认为:PCIe总线的功能还是无法满足高性能存储和网络独特的I/O需求。     

Equilibria,fixed points,and complexity classes

Many models from a variety of areas involve the computation of an equilibrium or fixed point of some kind. Examples include Nash equilibria in games; market equilibria; computing optimal strategies and the values of competitive games (stochastic and other games); stable configurations of neural networks; analysing basic stochastic models for evolution like branching processes and for language like stochastic context-free grammars; and models that incorporate the basic primitives of probability and recursion like recursive Markov chains. It is not known whether these problems can be solved in polynomial time. There are certain common computational principles underlying different types of equilibria, which are captured by the complexity classes PLS, PPAD, and FIXP. Representative complete problems for these classes are, respectively, pure Nash equilibria in games where they are guaranteed to exist, (mixed) Nash equilibria in two-player normal form games, and (mixed) Nash equilibria in normal form games with three (or more) players. This paper reviews the underlying computational principles and the corresponding classes.     

An Efficient Algorithm for Minimizing Real-Time Transition Systems

We address the problem of performing simultaneously reachability analysis and minimization of real-time transition systems represented by timed automata, i.e., automata extended with a finite set of clock variables. The transitions of the automaton may depend on the values of the clocks and may reset some of the clocks. An efficient algorithm is presented for minimizing a system with respect to a given initial partition that respects the enabling conditions of the transitions of the timed automaton. Our algorithm generates the portion of the minimized system that is reachable from a given initial configuration in time polynomial in the input and the size of the minimal reachable system.     

Output-associative RVM regression for dimensional and continuous emotion prediction

Many problems in machine learning and computer vision consist of predicting multi-dimensional output vectors given a specific set of input features. In many of these problems, there exist inherent temporal and spatial dependencies between the output vectors, as well as repeating output patterns and input–output associations, that can provide more robust and accurate predictors when modeled properly. With this intrinsic motivation, we propose a novel Output-Associative Relevance Vector Machine (OA-RVM) regression framework that augments the traditional RVM regression by being able to learn non-linear input and output dependencies. Instead of depending solely on the input patterns, OA-RVM models output covariances within a predefined temporal window, thus capturing past, current and future context. As a result, output patterns manifested in the training data are captured within a formal probabilistic framework, and subsequently used during inference. As a proof of concept, we target the highly challenging problem of dimensional and continuous prediction of emotions, and evaluate the proposed framework by focusing on the case of multiple nonverbal cues, namely facial expressions, shoulder movements and audio cues. We demonstrate the advantages of the proposed OA-RVM regression by performing subject-independent evaluation using the SAL database that constitutes naturalistic conversational interactions. The experimental results show that OA-RVM regression outperforms the traditional RVM and SVM regression approaches in terms of accuracy of the prediction (evaluated using the Root Mean Squared Error) and structure of the prediction (evaluated using the correlation coefficient), generating more accurate and robust prediction models.     

The berth allocation problem with stochastic vessel handling times

In this paper, the berth allocation problem with stochastic vessel handling times is formulated as a bi-objective problem. To solve the resulting problem, an evolutionary algorithm-based heuristic and a simulation-based Pareto front pruning algorithm is proposed. Computational examples show that the proposed approach provides solutions superior to the ones where the expected value of the vessel handling times is used.     

Multilayer Resuspension of Small Identical Particles by Turbulent Flow

ABSTRACT

A model for the resuspension of a multilayer deposit by turbulent flow is developed. The resuspension rate is obtained by solving a set of coupled, first-order kinetic equations. The multilayer resuspension rate depends explicitly on single-particle resuspension rates that are determined from a modified energy-transfer model. The surface-particle and particle-particle interaction potentials are calculated by a microscopic approach based on the integration of the Lennard-Jones intermolecular interaction potential. The effect of the surface roughness, which leads to a distribution of the adhesive forces, is considered, as well as the energy transfer from the fluctuating part of the turbulent flow to the particle. It is shown that for a geometrical arrangement of deposited particles with a co-ordination number of two (particles stacked on top of each other) particles from the top layers resuspend at lower friction velocities than particles adjacent to the surface. The predicted long-term resuspension rate decays algebraically with exposure time. Calculations are presented for a two-layer deposit of either SnO₂ and Al₂O₃ particles on a stainless steel surface.     

Minimum and maximum delay problems in real-time systems

We consider a finite-state system with a finite number of clocks, where the transitions may depend on the values of the clocks, and may reset some of the clocks. We address the complexity and provide algorithms for the following problems. Suppose that the system starts from a given current state with a given assignment of values to the clocks. Can a given target state ever appear in the history of the system? What is the earliest time it can appear? What is the latest time it can appear?     

The photophysics and two-photon absorption of a series of quadrupolar and tribranched molecules: The role of the edge substituent

A series of quadrupolar and tribranched molecules were synthesized in order to examine the role of the edge substituents on their photophysical and two-photon absorption properties. Two-photon absorption cross sections, δ, of the molecules were determined in THF solution using a two-photon excited fluorescence technique with femtosecond pulsed excitation. The quadrupolar molecules contained a fluorene or alcoxy-substituted phenylene central core together with various electron accepting edge substituents such as pyridine, terpyridine, phthalimide and naphthalimide. The tribranched molecules contained triphenylamine at the center and terpyridine or phthalimide substituents at the periphery. It was found that edge phthalimide substituent favour high δ values. δ Values as high as 1660 GM and 1500 GM were obtained from the phthalimide-fluorene-phthalimide and phthalimide-phenylene-phthalimide molecules, respectively; in the case of the tribranched molecule with a phthalimide substituent, a δ-value of 1200 GM was found.     

Deep Affect Prediction in-the-Wild: Aff-Wild Database and Challenge,Deep Architectures,and Beyond

International Journal of Computer Vision - Automatic understanding of human affect using visual signals is of great importance in everyday human–machine interactions. Appraising human...